Method and apparatus for supporting protection for control frame in wireless LAN system

Abstract

Disclosed are a method and an apparatus for supporting protection for a control frame in a wireless LAN system. A method performed by a first STA in a wireless local area network (WLAN) system, according to an embodiment of the present disclosure, may comprise the steps of: identifying key information related to protection for a control frame; receiving, from a second STA, a control frame comprising information encrypted on the basis of a specific encryption protocol; and decrypting the encrypted information and performing an integrity check for the control frame on the basis of the key information. Here, the encrypted information may be configured on the basis of encryption for a common information field and one or more user information fields in the control frame.

Description

Method and device for supporting protection of control frames in a wireless LAN system

[0001] The present disclosure relates to a method and device for supporting protection of a control frame in a wireless local area network (WLAN) system.

[0002] New technologies have been introduced for wireless local area networks (WLANs) to improve transmission rates, increase bandwidth, enhance reliability, reduce errors, and reduce latency. Among WLAN technologies, the IEEE (Institute of Electrical and Electronics Engineers) 802.11 series of standards can be referred to as Wi-Fi. For example, recently introduced technologies for WLANs include enhancements for Very High Throughput (VHT) in the 802.11ac standard and enhancements for High Efficiency (HE) in the IEEE 802.11ax standard.

[0003] To provide a more advanced wireless communication environment, improved technologies for Extremely High Throughput (EHT) are being discussed. For example, technologies for Multiple Input Multiple Output (MIMO), which supports increased bandwidth, efficient utilization of multiple bands, and increased spatial streams, and for coordination of multiple access points (APs), are being studied. In particular, various technologies are being studied to support low latency or real-time traffic. Furthermore, new technologies are being discussed to support ultra-high reliability (UHR), including improvements or extensions of EHT technology.

[0004] The technical problem of the present disclosure is to provide a method and device for supporting protection of a control frame in a wireless LAN system.

[0005] The technical problem of the present disclosure is to provide a method and device for securing confidentiality and integrity based on CCMP (Counter Mode with cipher-block chaining message authentication code protocol) / GCMP (Galois / Counter Mode protocol) for a trigger frame in a wireless LAN system.

[0006] The technical problems to be achieved in the present disclosure are not limited to the technical problems mentioned above, and other technical problems not mentioned will be clearly understood by a person having ordinary skill in the technical field to which the present disclosure belongs from the description below.

[0007] A method performed by a first station (STA) in a wireless local area network (WLAN) system according to one aspect of the present disclosure may include: verifying key information related to protection for a control frame; receiving a control frame including encrypted information based on a specific encryption protocol from a second STA; and performing decryption of the encrypted information and an integrity check on the control frame based on the key information. Here, the encrypted information may be configured based on encryption of a common information field and one or more user information fields within the control frame.

[0008] A method performed by a second station (STA) in a wireless local area network (WLAN) system according to an additional aspect of the present disclosure comprises: identifying key information related to protection for a control frame; constructing a control frame including encrypted information based on the key information and a specific encryption protocol; and transmitting the control frame to a first STA, wherein the encrypted information may be constructed based on encryption of a common information field and one or more user information fields within the control frame.

[0009] According to various embodiments of the present disclosure, a method and device for supporting protection for a control frame in a wireless LAN system may be provided.

[0010] According to various embodiments of the present disclosure, a method and device for securing confidentiality and integrity based on CCMP (Counter Mode with cipher-block chaining message authentication code protocol) / GCMP (Galois / Counter Mode protocol) for a trigger frame in a wireless LAN system may be provided.

[0011] The effects that can be obtained from the present disclosure are not limited to the effects mentioned above, and other effects that are not mentioned will be clearly understood by a person having ordinary skill in the art to which the present disclosure pertains from the description below.

[0012] The accompanying drawings, which are incorporated in and are part of the detailed description to aid in understanding the present disclosure, provide embodiments of the present disclosure and, together with the detailed description, describe the technical features of the present disclosure.

[0013] FIG. 1 illustrates a block diagram of a wireless communication device according to one embodiment of the present disclosure.

[0014] FIG. 2 is a diagram showing an exemplary structure of a wireless LAN system to which the present disclosure can be applied.

[0015] FIG. 3 is a diagram for explaining a link setup process to which the present disclosure can be applied.

[0016] FIG. 4 is a diagram for explaining a backoff process to which the present disclosure can be applied.

[0017] FIG. 5 is a diagram for explaining a CSMA / CA-based frame transmission operation to which the present disclosure can be applied.

[0018] FIG. 6 is a drawing for explaining an example of a frame structure used in a wireless LAN system to which the present disclosure can be applied.

[0019] FIG. 7 is a diagram illustrating examples of PPDUs defined in the IEEE 802.11 standard to which the present disclosure can be applied.

[0020] FIG. 8 is a drawing showing an exemplary format of a trigger frame to which the present disclosure can be applied.

[0021] Figure 9 illustrates a CCMP MPDU structure applicable to the present disclosure.

[0022] Figure 10 illustrates a CCMP encryption encapsulation process that can be applied to the present disclosure.

[0023] Figure 11 illustrates a CCMP decapsulation process applicable to the present disclosure.

[0024] Figure 12 illustrates a GCMP MPDU structure applicable to the present disclosure.

[0025] Figure 13 illustrates a GCMP encryption encapsulation process that can be applied to the present disclosure.

[0026] Figure 14 illustrates a GCMP decapsulation process applicable to the present disclosure.

[0027] FIG. 15 illustrates a CCMP MPDU format according to an embodiment of the present disclosure.

[0028] FIG. 16 illustrates a GCMP MPDU format according to an embodiment of the present disclosure.

[0029] FIG. 17 illustrates the operation of a transmitting STA that supports protection for a trigger frame according to the present disclosure.

[0030] FIG. 18 illustrates the operation of a receiving STA that supports protection for a trigger frame according to the present disclosure.

[0031] FIG. 19 is a diagram illustrating an example of a method performed by a first STA according to the present disclosure.

[0032] FIG. 20 is a drawing for explaining an example of a method performed by a second STA according to the present disclosure.

[0033] Hereinafter, preferred embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. The detailed description set forth below, together with the accompanying drawings, is intended to explain exemplary embodiments of the present disclosure and is not intended to represent the only embodiments in which the present disclosure may be practiced. The following detailed description includes specific details to provide a thorough understanding of the present disclosure. However, one of ordinary skill in the art will appreciate that the present disclosure may be practiced without these specific details.

[0034] In some cases, to avoid obscuring the concepts of the present disclosure, known structures and devices may be omitted or illustrated in block diagram form focusing on the core functions of each structure and device.

[0035] In the present disclosure, when a component is said to be "connected," "coupled," or "connected" to another component, this may include not only a direct connection but also an indirect connection in which another component exists between them. Furthermore, the terms "comprises" or "has" in the present disclosure specify the presence of the mentioned 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.

[0036] In this disclosure, terms such as “first,” “second,” etc. are used only to distinguish one component from another and are not used to limit the components, and do not limit the order or importance between the components unless specifically stated otherwise. Accordingly, within the scope of this disclosure, a first component in one embodiment may be referred to as a second component in another embodiment, and similarly, a second component in one embodiment may be referred to as a first component in another embodiment.

[0037] The terminology used herein is for the purpose of describing particular embodiments and is not intended to limit the scope of the claims. As used in the description of the embodiments and the appended claims, the singular forms "a," "an," and "the" are intended to include the plural forms as well, unless the context clearly dictates otherwise. The term "and / or" as used herein may refer to any one of the associated enumerated items, or is meant to refer to and encompass any and all possible combinations of two or more of them. Furthermore, the use of " / " between words in this disclosure has the same meaning as "and / or" unless otherwise stated.

[0038] The examples of the present disclosure can be applied to various wireless communication systems. For example, the examples of the present disclosure can be applied to a wireless LAN system. For example, the examples of the present disclosure can be applied to a wireless LAN based on the IEEE 802.11a / g / n / ac / ax / be standards. Furthermore, the examples of the present disclosure can be applied to a wireless LAN based on the newly proposed IEEE 802.11bn (or UHR) standard. Additionally, the examples of the present disclosure can be applied to a wireless LAN based on the next-generation standard after IEEE 802.11bn. Furthermore, the examples of the present disclosure can be applied to a cellular wireless communication system. For example, the examples of the present disclosure can be applied to a cellular wireless communication system based on the LTE (Long Term Evolution) series of technologies and the 5G NR (New Radio) series of technologies of the 3rd Generation Partnership Project (3GPP) standard.

[0039] Below, technical features to which examples of the present disclosure can be applied are described.

[0040] FIG. 1 illustrates a block diagram of a wireless communication device according to one embodiment of the present disclosure.

[0041] The first device (100) and the second device (200) illustrated in FIG. 1 may be replaced with 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. In addition, the first device (100) and the second device (200) may be replaced with 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.

[0042] The devices (100, 200) illustrated in FIG. 1 may also be referred to as stations (STAs). For example, the devices (100, 200) illustrated in FIG. 1 may be referred to by various terms such as transmitting device, receiving device, transmitting STA, and receiving STA. For example, the STAs (110, 200) may perform an AP (access point) role or a non-AP role. That is, in the present disclosure, the STAs (110, 200) may perform the functions of an AP and / or a non-AP. When the STAs (110, 200) perform an AP function, they may simply be referred to as APs, and when the STAs (110, 200) perform a non-AP function, they may simply be referred to as STAs. In addition, in the present disclosure, the APs may also be referred to as AP STAs.

[0043] Referring to FIG. 1, the first device (100) and the second device (200) can transmit and receive wireless signals through various wireless LAN technologies (e.g., IEEE 802.11 series). The first device (100) and the second device (200) can include interfaces for a medium access control (MAC) layer and a physical layer (PHY) that follow the provisions of the IEEE 802.11 standard.

[0044] In addition, the first device (100) and the second device (200) may additionally support various communication standards (e.g., 3GPP LTE series, 5G NR series standards, etc.) other than wireless LAN technology. In addition, the device of the present disclosure may be implemented as various devices such as a mobile phone, a vehicle, a personal computer, an AR (Augmented Reality) device, a VR (Virtual Reality) device, etc. In addition, the STA of the present specification may support various communication services such as voice calls, video calls, data communications, autonomous driving, MTC (Machine-Type Communication), M2M (Machine-to-Machine), D2D (Device-to-Device), and IoT (Internet-of-Things).

[0045] A 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 memories (104) and / or the transceivers (106), and may be configured to implement the descriptions, functions, procedures, proposals, methods, and / or operational flowcharts disclosed in the present disclosure. For example, the processor (102) may process information in the memories (104) to generate first information / signals, and then transmit a wireless signal including the first information / signals via the transceivers (106). Furthermore, the processor (102) may receive a wireless signal including second information / signals via the transceivers (106), and then store information obtained from signal processing of the second information / signals in the memory (104). The memory (104) may be connected to the processor (102) and may store various information related to the operation of the processor (102). For example, the memory (104) may perform some or all of the processes controlled by the processor (102), or may store software code including instructions for performing the descriptions, functions, procedures, proposals, methods, and / or operation flowcharts disclosed in the present disclosure. Here, the processor (102) and the memory (104) may be part of a communication modem / circuit / chip designed to implement a wireless LAN technology (e.g., IEEE 802.11 series). The transceiver (106) may be connected to the processor (102) and may transmit and / or receive wireless signals via one or more antennas (108). The transceiver (106) may include a transmitter and / or a receiver. The transceiver (106) may be used interchangeably with an RF (Radio Frequency) unit. In the present disclosure, a device may also mean a communication modem / circuit / chip.

[0046] The second device (200) includes one or more processors (202), 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 memories (204) and / or the transceivers (206), and may be configured to implement the descriptions, functions, procedures, proposals, methods, and / or operational flowcharts disclosed in the present disclosure. For example, the processor (202) may process information in the memory (204) to generate third information / signals, and then transmit a wireless signal including the third information / signals via the transceivers (206). Furthermore, the processor (202) may receive a wireless signal including fourth information / signals via the transceivers (206), and then store information obtained from signal processing of the fourth information / signals in the memory (204). The memory (204) may be connected to the processor (202) and may store various information related to the operation of the processor (202). For example, the memory (204) may perform some or all of the processes controlled by the processor (202), or may store software code including instructions for performing the descriptions, functions, procedures, proposals, methods, and / or operation flowcharts 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 a wireless LAN technology (e.g., IEEE 802.11 series). The transceiver (206) may be connected to the processor (202) and may transmit and / or receive wireless signals via one or more antennas (208). The transceiver (206) may include a transmitter and / or a receiver. The transceiver (206) may be used interchangeably with an RF unit. In the present disclosure, a device may also mean a communication modem / circuit / chip.

[0047] Hereinafter, the hardware elements of the device (100, 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, 202). For example, one or more processors (102, 202) may implement one or more layers (e.g., functional layers such as PHY, MAC). One or more processors (102, 202) may generate one or more Protocol Data Units (PDUs) and / or one or more Service Data Units (SDUs) according to the descriptions, functions, procedures, proposals, methods, and / or operational flowcharts disclosed in the present disclosure. One or more processors (102, 202) may generate messages, control information, data, or information according to the descriptions, functions, procedures, proposals, methods, and / or operational flowcharts disclosed in the present disclosure. One or more processors (102, 202) can generate signals (e.g., baseband signals) including PDUs, SDUs, messages, control information, data or information according to the functions, procedures, proposals and / or methods disclosed in the present disclosure, and provide the signals to one or more transceivers (106, 206). One or more processors (102, 202) can receive signals (e.g., baseband signals) from one or more transceivers (106, 206) and obtain PDUs, SDUs, messages, control information, data or information according to the descriptions, functions, procedures, proposals, methods and / or operational flowcharts disclosed in the present disclosure.

[0048] One or more processors (102, 202) may be referred to as a controller, a microcontroller, a microprocessor, or a microcomputer. One or more processors (102, 202) may be implemented by hardware, firmware, software, or a combination thereof. For example, one or more Application Specific Integrated Circuits (ASICs), one or more Digital Signal Processors (DSPs), one or more Digital Signal Processing Devices (DSPDs), one or more Programmable Logic Devices (PLDs), or one or more Field Programmable Gate Arrays (FPGAs) may be included in one or more processors (102, 202). The descriptions, functions, procedures, proposals, methods, and / or operational flowcharts disclosed in this disclosure may be implemented using firmware or software, and the firmware or software may be implemented to include modules, procedures, functions, etc. The descriptions, functions, procedures, proposals, methods and / or operation flowcharts disclosed in this disclosure may be implemented using firmware or software configured to perform one or more processors (102, 202) or stored in one or more memories (104, 204) and driven by one or more processors (102, 202). The descriptions, functions, procedures, proposals, methods and / or operation flowcharts disclosed in this disclosure may be implemented using firmware or software in the form of codes, instructions and / or sets of instructions.

[0049] One or more memories (104, 204) may be coupled to one or more processors (102, 202) and may store various forms of data, signals, messages, information, programs, codes, instructions, and / or commands. The one or more memories (104, 204) may be configured as ROM, RAM, EPROM, flash memory, hard drives, registers, cache memory, computer-readable storage media, and / or combinations thereof. The one or more memories (104, 204) may be located internally and / or externally to the one or more processors (102, 202). Additionally, the one or more memories (104, 204) may be coupled to the one or more processors (102, 202) via various technologies, such as wired or wireless connections.

[0050] One or more transceivers (106, 206) can transmit user data, control information, wireless signals / channels, etc., as mentioned in the methods and / or flowcharts of the present disclosure, to one or more other devices. One or more transceivers (106, 206) can receive user data, control information, wireless signals / channels, etc., as mentioned in the descriptions, functions, procedures, proposals, methods and / or flowcharts of the present disclosure, from one or more other devices. For example, one or more transceivers (106, 206) can be coupled to one or more processors (102, 202) and can transmit and receive wireless signals. For example, one or more processors (102, 202) can control one or more transceivers (106, 206) to transmit user data, control information, or wireless signals to one or more other devices. Additionally, one or more processors (102, 202) may control one or more transceivers (106, 206) to receive user data, control information, or wireless signals from one or more other devices. Additionally, one or more transceivers (106, 206) may be coupled 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, wireless signals / channels, or the like, as referred to in the descriptions, functions, procedures, proposals, methods, and / or operational flowcharts disclosed in the present disclosure, via one or more antennas (108, 208). In the present disclosure, one or more antennas may be multiple physical antennas or multiple logical antennas (e.g., antenna ports). One or more transceivers (106, 206) can convert received user data, control information, wireless signals / channels, etc. from RF band signals to baseband signals in order to process the received user data, control information, wireless signals / channels, etc. using one or more processors (102, 202).One or more transceivers (106, 206) may convert user data, control information, wireless signals / channels, etc. processed by one or more processors (102, 202) from baseband signals to RF band signals. For this purpose, one or more transceivers (106, 206) may include an (analog) oscillator and / or filter.

[0051] For example, one of the STAs (100, 200) may perform the intended operation of an AP, and the other of the STAs (100, 200) may perform the intended operation of a non-AP STA. For example, the transceivers (106, 206) of FIG. 1 may perform transmission and reception operations of signals (e.g., packets or PPDUs (Physical layer Protocol Data Units) according to IEEE 802.11a / b / g / n / ac / ax / be / bn, etc.). In addition, in the present disclosure, operations in which various STAs generate transmission and reception signals or perform data processing or calculations in advance for transmission and reception signals may be performed in the processors (102, 202) of FIG. 1. For example, an example of an operation for generating a transmission / reception signal or performing data processing or operation in advance for a transmission / reception signal may include 1) an operation for determining / obtaining / configuring / computing / decoding / encoding bit information of a field (SIG (signal), STF (short training field), LTF (long training field), Data, etc.) included in a PPDU, 2) an operation for determining / configuring / obtaining time resources or frequency resources (e.g., subcarrier resources) used for a field (SIG, STF, LTF, Data, etc.) included in a PPDU, 3) an operation for determining / configuring / obtaining a specific sequence (e.g., a pilot sequence, an STF / LTF sequence, an extra sequence applied to SIG) used for a field (SIG, STF, LTF, Data, etc.) included in a PPDU, 4) a power control operation and / or a power saving operation applied to an STA, 5) an operation related to determining / obtaining / configuring / computing / decoding / encoding an ACK signal, etc. Additionally, in the examples below, various information (e.g., information related to fields / subfields / control fields / parameters / power, etc.) used by various STAs for determining / acquiring / configuring / computing / decoding / encoding transmission / reception signals can be stored in the memory (104, 204) of FIG. 1.

[0052] Hereinafter, downlink (DL) refers to a link for communication from an AP STA to a non-AP STA, and downlink PPDUs / packets / signals, etc. can be transmitted and received through the downlink. In downlink communication, the transmitter may be part of an AP STA, and the receiver may be part of a non-AP STA. Uplink (UL) refers to a link for communication from a non-AP STA to an AP STA, and uplink PPDUs / packets / signals, etc. can be transmitted and received through the uplink. In uplink communication, the transmitter may be part of a non-AP STA, and the receiver may be part of an AP STA.

[0053] FIG. 2 is a diagram showing an exemplary structure of a wireless LAN system to which the present disclosure can be applied.

[0054] The structure of a wireless LAN system can be composed of multiple components. Through the interaction of multiple components, a wireless LAN that supports transparent STA mobility to the upper layer can be provided. A Basic Service Set (BSS) corresponds to a basic building block of a wireless LAN. FIG. 2 illustrates, by way of example, the existence of two BSSs (BSS1 and BSS2) and the inclusion of two STAs as members of each BSS (STA1 and STA2 are included in BSS1, and STA3 and STA4 are included in BSS2). The oval representing a BSS in FIG. 2 can also be understood as representing a coverage area in which STAs included in the corresponding BSS maintain communication. This area can be referred to as a Basic Service Area (BSA). When an STA moves outside of a BSA, it cannot directly communicate with other STAs within the BSA.

[0055] If we do not consider the DS illustrated in Figure 2, the most basic type of BSS in a wireless LAN is an Independent BSS (IBSS). For example, an IBSS can have a minimal form consisting of only two STAs. For example, assuming other components are omitted, BSS1 consisting of only STA1 and STA2, or BSS2 consisting of only STA3 and STA4, can be representative examples of an IBSS, respectively. Such a configuration is possible when the STAs can communicate directly without an AP. Furthermore, in this type of WLAN, a LAN can be configured when needed rather than being planned in advance, and this can be called an ad-hoc network. Since an IBSS does not include an AP, there is no centralized management entity. That is, in an IBSS, STAs are managed in a distributed manner. In IBSS, all STAs can be mobile STAs, and access to distributed systems (DS) is not permitted, forming a self-contained network.

[0056] An STA's membership in a BSS can dynamically change, for example, when an STA is turned on or off, or when an STA enters or leaves a BSS area. To become a member of a BSS, an STA can join the BSS using a synchronization process. To access all services in the BSS infrastructure, an STA must be associated with the BSS. This association can be dynamically established and may involve the use of a Distribution System Service (DSS).

[0057] In a wireless LAN, the direct STA-to-STA distance can be limited by PHY performance. While this distance limit may be sufficient in some cases, communication between STAs over longer distances may be required in other cases. To support extended coverage, a distributed system (DS) can be configured.

[0058] DS refers to a structure in which BSSs are interconnected. Specifically, a BSS may exist as an extended component of a network composed of multiple BSSs, as illustrated in Figure 2. DS is a logical concept and can be specified by the characteristics of a distributed system medium (DSM). In this regard, the Wireless Medium (WM) and DSM can be logically distinguished. Each logical medium is used for a different purpose and by different components. These media are neither limited to being identical nor limited to being different. This logical difference between multiple media explains the flexibility of the WLAN architecture (DS architecture or other network architectures). In other words, the WLAN architecture can be implemented in various ways, and the physical characteristics of each implementation can independently specify the WLAN architecture.

[0059] A DS can support mobile devices by providing seamless integration of multiple BSSs and the logical services necessary to handle addresses to destinations. Additionally, a DS may further include a component called a portal, which acts as a bridge for connecting wireless LANs to other networks (e.g., IEEE 802.X).

[0060] An AP is an entity that enables access to a DS through a WM for associated non-AP STAs and also has the functionality of an STA. Data movement between a BSS and a DS can be performed through an AP. For example, STA2 and STA3 illustrated in FIG. 2 have the functionality of an STA and provide the function of allowing associated non-AP STAs (STA1 and STA4) to access the DS. In addition, since all APs are basically STAs, all APs are addressable entities. The address used by an AP for communication on a WM and the address used by an AP for communication on a DSM do not necessarily have to be the same. A BSS consisting of an AP and one or more STAs can be referred to as an infrastructure BSS.

[0061] Data transmitted from one of the STA(s) associated with an AP to the STA address of that AP may always be received on an uncontrolled port and processed by an IEEE 802.1X port access entity. In addition, if the controlled port is authenticated, the transmitted data (or frame) may be forwarded to the DS.

[0062] In addition to the structure of the DS described above, an extended service set (ESS) may be established to provide wider coverage.

[0063] An ESS is a network of arbitrary size and complexity, consisting of DSs and BSSs. An ESS may correspond to a set of BSSs connected to a DS. However, an ESS does not include a DS. An ESS network is characterized by appearing as an IBSS at the Logical Link Control (LLC) layer. STAs within an ESS can communicate with each other, and mobile STAs can move from one BSS to another (within the same ESS) transparently to the LLC. APs within an ESS may have the same SSID (service set identification). The SSID is distinct from the BSSID, which is the identifier of the BSS.

[0064] In a wireless LAN system, no assumptions are made about the relative physical locations of BSSs, and all of the following configurations are possible: BSSs can be partially overlapping, which is commonly used to provide continuous coverage. BSSs can also be physically disconnected, and there is no logical distance limit between them. BSSs can also be physically co-located, which can be used to provide redundancy. Furthermore, one (or more) IBSS or ESS networks can physically co-exist with one (or more) ESS networks. This can occur in cases where an ad-hoc network operates at the same location as an ESS network, where physically overlapping wireless networks are configured by different organizations, or where two or more different access and security policies are required at the same location.

[0065] FIG. 3 is a diagram for explaining a link setup process to which the present disclosure can be applied.

[0066] For an STA to set up a link and transmit and receive data on a network, it must first discover the network, perform authentication, establish an association, and complete security authentication procedures. The link setup process can also be referred to as the session initiation process or session setup process. Furthermore, the discovery, authentication, association, and security setup processes of the link setup process can be collectively referred to as the association process.

[0067] In step S310, the STA may perform a network discovery operation. This network discovery operation may include scanning operations by the STA. That is, for the STA to access a network, it must search for available networks. Before joining a wireless network, the STA must identify compatible networks. The process of identifying networks in a specific area is called scanning.

[0068] Scanning methods include active scanning and passive scanning. Figure 3 illustrates a network discovery operation including an active scanning process as an example. In active scanning, an STA performing scanning transmits a probe request frame to discover any APs in the vicinity while moving between channels and waits for a response. The responder transmits a probe response frame in response to the STA that transmitted the probe request frame. Here, the responder may be the STA that last transmitted a beacon frame in the BSS of the channel being scanned. In the BSS, the AP transmits the beacon frame, so the AP becomes the responder. In the IBSS, the STAs within the IBSS take turns transmitting beacon frames, so the responder is not fixed. For example, an STA that transmits a probe request frame on channel 1 and receives a probe response frame on channel 1 can store BSS-related information included in the received probe response frame and move to the next channel (e.g., channel 2) to perform scanning (i.e., transmitting and receiving probe requests / responses on channel 2) in the same manner.

[0069] Although not shown in Figure 3, the scanning operation can also be performed in a passive scanning manner. In passive scanning, the STA performing the scanning moves between channels and waits for a beacon frame. A beacon frame is one of the management frames defined in IEEE 802.11. It announces the existence of a wireless network and is periodically transmitted so that the STA performing the scanning can find the wireless network and participate in the wireless network. In the BSS, the AP performs the role of periodically transmitting the beacon frame, and in the IBSS, the STAs within the IBSS take turns transmitting the beacon frame. When the STA performing the scanning receives a beacon frame, it stores the information about the BSS included in the beacon frame and moves to another channel, recording the beacon frame information on each channel. The STA receiving the beacon frame stores the BSS-related information included in the received beacon frame and moves to the next channel to perform scanning on the next channel in the same manner. Comparing active scanning and passive scanning, active scanning has the advantage of lower delay and power consumption than passive scanning.

[0070] After the STA discovers the network, an authentication process may be performed in step S320. This authentication process may be referred to as the first authentication process to clearly distinguish it from the security setup operation of step S340 described below.

[0071] The authentication process involves the STA sending an authentication request frame to the AP, and the AP responding by sending an authentication response frame to the STA. The authentication frame used for the authentication request / response corresponds to a management frame.

[0072] The authentication frame may include information such as an authentication algorithm number, an authentication transaction sequence number, a status code, a challenge text, a Robust Security Network (RSN), and a Finite Cyclic Group. These are just some examples of information that may be included in an authentication request / response frame, and may be replaced with other information or include additional information.

[0073] An STA can send an authentication request frame to an AP. The AP can determine whether to grant authentication to the STA based on the information contained in the received authentication request frame. The AP can provide the result of the authentication process to the STA via an authentication response frame.

[0074] After the STA is successfully authenticated, an association process may be performed in step S330. The association process includes a process in which the STA transmits an association request frame to the AP, and in response, the AP transmits an association response frame to the STA.

[0075] For example, the association request frame may include information about various capabilities, a beacon listen interval, a service set identifier (SSID), supported rates, supported channels, an RSN, a mobility domain, supported operating classes, a Traffic Indication Map Broadcast request, interworking service capabilities, etc. For example, the association response frame may include information about various capabilities, a status code, an Association ID (AID), supported rates, an Enhanced Distributed Channel Access (EDCA) parameter set, a Received Channel Power Indicator (RCPI), a Received Signal to Noise Indicator (RSNI), a mobility domain, a timeout interval (e.g., an association comeback time), overlapping BSS scan parameters, a TIM broadcast response, a Quality of Service (QoS) map, etc. These are just some examples of information that may be included in a combined request / response frame, and may be replaced by other information or include additional information.

[0076] After the STA successfully joins the network, a security setup process may be performed in step S340. The security setup process in step S340 may be referred to as an authentication process through a Robust Security Network Association (RSNA) request / response, the authentication process in step S320 may be referred to as a first authentication process, and the security setup process in step S340 may also be referred to simply as an authentication process.

[0077] The security setup process of step S340 may include, for example, a process of establishing a private key through a four-way handshaking using an Extensible Authentication Protocol over LAN (EAPOL) frame. Furthermore, the security setup process may be performed according to a security method not defined in the IEEE 802.11 standard.

[0078] FIG. 4 is a diagram for explaining a backoff process to which the present disclosure can be applied.

[0079] In wireless LAN systems, the basic access mechanism of MAC (Medium Access Control) is Carrier Sense Multiple Access with Collision Avoidance (CSMA / CA). The CSMA / CA mechanism, also known as the Distributed Coordination Function (DCF) of the IEEE 802.11 MAC, essentially employs a "listen before talk" access mechanism. According to this type of access mechanism, the AP and / or STA may perform a Clear Channel Assessment (CCA) to sense the wireless channel or medium for a predetermined time period (e.g., a DCF Inter-Frame Space (DIFS)) before starting transmission. If the sensing result determines that the medium is in an idle state, the AP and / or STA may start transmitting frames through the medium. On the other hand, if the medium is detected to be occupied or busy, the AP and / or STA may not start its own transmission, but may wait for a delay period (e.g., a random backoff period) for medium access before attempting to transmit frames. By applying a random backoff period, multiple STAs are expected to attempt to transmit frames after waiting for different periods of time, thereby minimizing collisions.

[0080] In addition, the IEEE 802.11 MAC protocol provides the Hybrid Coordination Function (HCF). The HCF is based on the DCF and the Point Coordination Function (PCF). The PCF is a polling-based synchronous access method that periodically polls all receiving APs and / or STAs to ensure that they receive data frames. In addition, the HCF has the Enhanced Distributed Channel Access (EDCA) and the HCF Controlled Channel Access (HCCA). The EDCA is a contention-based access method for a provider to provide data frames to multiple users, while the HCCA uses a non-contention-based channel access method that utilizes a polling mechanism. In addition, the HCF includes a medium access mechanism to improve the Quality of Service (QoS) of the wireless LAN, and can transmit QoS data in both the Contention Period (CP) and the Contention Free Period (CFP).

[0081] Referring to Fig. 4, an operation based on a random backoff period is described. When a medium that was occupied / busy changes to an idle state, multiple STAs can attempt to transmit data (or frames). To minimize collisions, each STA can select a random backoff count, wait for the corresponding slot time, and then attempt transmission. The random backoff count has a pseudo-random integer value and can be determined as one of the values ​​in the range of 0 to CW. Here, CW is a contention window parameter value. The CW parameter is given an initial value of CWmin, but can take a value doubled in case of transmission failure (e.g., when an ACK for a transmitted frame is not received). When the CW parameter value becomes CWmax, data transmission can be attempted while maintaining the CWmax value until data transmission is successful, and if data transmission is successful, it is reset to the CWmin value. The CW, CWmin, and CWmax values ​​are 2. n It is desirable to set it to -1 (n=0, 1, 2, ...).

[0082] Once the random backoff process begins, the STA continues to monitor the medium while counting down the backoff slots according to the determined backoff count value. If the medium is monitored as occupied, the countdown stops and waits. When the medium becomes idle, the remaining countdown resumes.

[0083] In the example of FIG. 4, when a packet to be transmitted reaches the MAC of STA3, STA3 can immediately transmit a frame if it confirms that the medium is idle for DIFS. The remaining STAs monitor the medium for occupied / busy states and wait. In the meantime, data to be transmitted may also occur in each of STA1, STA2, and STA5, and each STA can count down the backoff slot according to a random backoff count value selected by each STA after waiting for DIFS if the medium is monitored as idle. Assume that STA2 selects the smallest backoff count value and STA1 selects the largest backoff count value. In other words, this example illustrates a case where the remaining backoff time of STA5 is shorter than the remaining backoff time of STA1 when STA2 finishes the backoff count and starts frame transmission. STA1 and STA5 briefly stop counting down and wait while STA2 occupies the medium. When STA2's occupation ends and the medium becomes idle again, STA1 and STA5 wait for DIFS and then resume the backoff count that they had stopped. That is, they can start transmitting frames after counting down the remaining backoff slots equal to the remaining backoff time. Since STA5's remaining backoff time is shorter than STA1's, STA5 starts transmitting frames. While STA2 occupies the medium, STA4 may also have data to transmit. From STA4's perspective, when the medium becomes idle, it waits for DIFS, counts down according to its selected random backoff count value, and then starts transmitting frames. In the example of Figure 4, the remaining backoff time of STA5 coincidentally matches the random backoff count value of STA4, in which case a collision may occur between STA4 and STA5. If a collision occurs, neither STA4 nor STA5 will receive an ACK, resulting in a failure in data transmission.In this case, STA4 and STA5 can select a random backoff count value and perform a countdown after doubling the CW value. STA1 waits while the medium is occupied by transmissions from STA4 and STA5, and when the medium becomes idle, it waits for DIFS and can start transmitting frames after the remaining backoff time elapses.

[0084] As in the example of Fig. 4, a data frame is a frame used for transmitting data forwarded to a higher layer, and can be transmitted after a backoff performed after DIFS elapses from when the medium becomes idle. Additionally, 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 performed after an IFS elapses, such as DIFS or PIFS (Point coordination function IFS). Subtype frames of a management frame include a beacon, an association request / response, a re-association request / response, a probe request / response, and an authentication request / response. A control frame is a frame used to control access to the medium. The subtype frames of the control frame include Request-To-Send (RTS), Clear-To-Send (CTS), Acknowledgment (ACK), Power Save-Poll (PS-Poll), Block ACK (BlockAck), Block ACK Request (BlockACKReq), Null Data Packet Announcement (NDP), and Trigger. If the control frame is not a response frame to the previous frame, it is transmitted after a backoff performed after the DIFS (Direct Inverse Frame Stop) has elapsed, and if it is a response frame to the previous frame, it is transmitted without a backoff performed after the SIFS (short IFS). The type and subtype of the frame can be identified by the type field and subtype field in the Frame Control (FC) field.

[0085] A QoS (Quality of Service) STA can transmit a frame after a backoff performed after the AIFS (arbitration IFS) for the access category (AC) to which the frame belongs, i.e., AIFS[i] (where i is a value determined by the AC), has elapsed. Here, the frames for which AIFS[i] can be used can be data frames, management frames, and also control frames that are not response frames.

[0086] FIG. 5 is a diagram for explaining a CSMA / CA-based frame transmission operation to which the present disclosure can be applied.

[0087] As mentioned above, the CSMA / CA mechanism includes virtual carrier sensing in addition to physical carrier sensing, in which STAs directly sense the medium. Virtual carrier sensing is intended to address potential issues in medium access, such as the hidden node problem. For virtual carrier sensing, the MAC of an STA can utilize a Network Allocation Vector (NAV). The NAV is a value that an STA that is currently using or has the right to use the medium indicates to other STAs the remaining time until the medium becomes available. Therefore, the value set as NAV corresponds to the period during which the STA transmitting the frame is scheduled to use the medium, and an STA receiving the NAV value is prohibited from accessing the medium during that period. For example, the NAV can be set based on the value of the "duration" field in the MAC header of the frame.

[0088] In the example of FIG. 5, it is assumed that STA1 wants to transmit data to STA2, and STA3 is in a position to overhear some or all of the frames transmitted and received between STA1 and STA2.

[0089] In order to reduce the possibility of collisions in transmissions of multiple STAs in a CSMA / CA-based frame transmission operation, a mechanism using RTS / CTS frames may be applied. In the example of FIG. 5, while STA1 is transmitting, STA3 may determine that the medium is idle based on carrier sensing results. That is, STA1 may correspond to a hidden node for STA3. Alternatively, in the example of FIG. 5, while STA2 is transmitting, STA3 may determine that the medium is idle based on carrier sensing results. That is, STA2 may correspond to a hidden node for STA3. By exchanging RTS / CTS frames before performing data transmission and reception between STA1 and STA2, STAs outside the transmission range of either STA1 or STA2, or STAs outside the carrier sensing range for transmissions from STA1 or STA3, may not attempt to occupy the channel during data transmission and reception between STA1 and STA2.

[0090] Specifically, STA1 can determine whether a channel is occupied through carrier sensing. In terms of physical carrier sensing, STA1 can determine channel occupancy idleness based on the energy level or signal correlation detected in the channel. Furthermore, in terms of virtual carrier sensing, STA1 can determine the channel occupancy status using a network allocation vector (NAV) timer.

[0091] STA1 can transmit an RTS frame to STA2 after performing a backoff if the channel is idle during the DIFS. STA2 can transmit a CTS frame, which is a response to the RTS frame, to STA1 after an SIFS if it receives the RTS frame.

[0092] If STA3 cannot overhear a CTS frame from STA2 but can overhear an RTS frame from STA1, STA3 can use the duration information contained in the RTS frame to set a NAV timer for the subsequent consecutively transmitted frame transmission period (e.g., SIFS + CTS frame + SIFS + data frame + SIFS + ACK frame). Alternatively, if STA3 cannot overhear an RTS frame from STA1 but can overhear a CTS frame from STA2, STA3 can use the duration information contained in the CTS frame to set a NAV timer for the subsequent consecutively transmitted frame transmission period (e.g., SIFS + data frame + SIFS + ACK frame). That is, if STA3 can overhear one or more of the RTS or CTS frames from one or more of STA1 or STA2, it can set a NAV accordingly. If STA3 receives a new frame before the NAV timer expires, it can update the NAV timer using the duration information contained in the new frame. STA3 does not attempt channel access until the NAV timer expires.

[0093] If STA1 receives a CTS frame from STA2, it can transmit a data frame to STA2 after SIFS from the time when the CTS frame is completely received. If STA2 successfully receives the data frame, it can transmit an ACK frame in response to the data frame to STA1 after SIFS. STA3 can determine whether the channel is in use through carrier sensing if the NAV timer expires. If STA3 determines that the channel is not in use by another terminal during the DIFS after the NAV timer expires, it can attempt channel access after a contention window (CW) based on a random backoff has elapsed.

[0094] FIG. 6 is a drawing for explaining an example of a frame structure used in a wireless LAN system to which the present disclosure can be applied.

[0095] The PHY layer can prepare an MPDU (MAC PDU) to be transmitted based on an instruction or primitive (meaning a set of instructions or parameters) from the MAC layer. For example, when a command requesting the start of transmission of the PHY layer is received from the MAC layer, the PHY layer can switch to transmission mode and transmit the information (e.g., data) provided by the MAC layer in the form of a frame. In addition, when the PHY layer detects a valid preamble of the received frame, it monitors the header of the preamble and sends a command to the MAC layer notifying the start of reception of the PHY layer.

[0096] In this way, information transmission / reception in a wireless LAN system is done in the form of frames, and for this purpose, the PHY layer Protocol Data Unit (PPDU) format is defined.

[0097] A basic PPDU may include a Short Training Field (STF), a Long Training Field (LTF), a SIGNAL (SIG) field, and a Data field. The most basic (e.g., non-HT (High Throughput) as illustrated in FIG. 7) PPDU format may consist of only the Legacy-STF (L-STF), Legacy-LTF (L-LTF), Legacy-SIG (L-SIG) fields, and a Data field. Additionally, 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 different types of) RL-SIG, U-SIG, non-legacy SIG field, 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. More specific details are described below with reference to FIG. 7.

[0098] STF is a signal for signal detection, AGC (Automatic Gain Control), diversity selection, and precise time synchronization, while LTF is a signal for channel estimation, frequency error estimation, etc. STF and LTF can be said to be signals for synchronization and channel estimation of the OFDM physical layer.

[0099] The SIG field may include various information related to PPDU transmission and reception. For example, the L-SIG field may consist of 24 bits and 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 include information about the modulation and coding rate of data. For example, the 12-bit Length field may include information about 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 a non-HT, HT, VHT, or EHT PPDU, the value of the Length field may be determined as a multiple of 3. For example, for HE PPDU, the value of the Length field can be determined as a multiple of 3 + 1 or a multiple of 3 + 2.

[0100] The data field may include a SERVICE field, a Physical layer Service Data Unit (PSDU), a PPDU TAIL bit, and, if necessary, padding bits. Some bits of the SERVICE field may be used to synchronize the descrambler at the receiving end. The PSDU corresponds to a MAC PDU defined at the MAC layer and may contain data generated / used by upper layers. The PPDU TAIL bit may be used to return the encoder to a 0 state. The padding bit may be used to adjust the length of the data field to a predetermined unit.

[0101] MAC PDUs are defined according to various MAC frame formats, and a basic MAC frame consists of a MAC header, a frame body, and a Frame Check Sequence (FCS). A MAC frame is composed of MAC PDUs and can be transmitted / received through the PSDU in the data portion of the PPDU format.

[0102] The MAC header includes a Frame Control field, a Duration / ID field, an Address field, etc. The Frame Control field may include control information required for frame transmission / reception. The Duration / ID field may be set to a time for transmitting the corresponding frame, etc. The Address subfields may indicate the receiver address, transmitter address, destination address, and source address of the frame, and some Address subfields may be omitted. For specific details of each subfield of the MAC header, including the Sequence Control, QoS Control, and HT Control subfields, refer to the IEEE 802.11 standard document.

[0103] The Null-Data PPDU (NDP) format refers to a PPDU format that does not include a data field. In other words, NDP refers to a frame format that includes a PPDU preamble (i.e., L-STF, L-LTF, L-SIG fields, and, if additionally present, non-legacy SIG, non-legacy STF, and non-legacy LTF) in the general PPDU format, and does not include the remaining part (i.e., data field).

[0104] FIG. 7 is a diagram illustrating examples of PPDUs defined in the IEEE 802.11 standard to which the present disclosure can be applied.

[0105] Standards such as IEEE 802.11a / g / n / ac / ax use various PPDU formats. 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)).

[0106] The HT PPDU format (IEEE 802.11n) additionally includes HT-SIG, HT-STF, and HT-LFT(s) fields in addition to the basic PPDU format. The HT PPDU format illustrated in Fig. 7(b) may be referred to as an HT-mixed format. Additionally, an HT-greenfield format PPDU may be defined, which corresponds to a format that does not include L-STF, L-LTF, and L-SIG, but consists of HT-GF-STF, HT-LTF1, HT-SIG, one or more HT-LTF, and Data fields (not illustrated).

[0107] An example of the VHT PPDU format (IEEE 802.11ac) includes VHT SIG-A, VHT-STF, VHT-LTF, and VHT-SIG-B fields in addition to the basic PPDU format (Fig. 7(c)).

[0108] An example of a HE PPDU format (IEEE 802.11ax) additionally includes RL-SIG (Repeated L-SIG), HE-SIG-A, HE-SIG-B, HE-STF, HE-LTF(s), and PE (Packet Extension) fields in addition to the basic PPDU format (Fig. 7(d)). Depending on specific examples of the HE PPDU format, some fields may be excluded or their lengths may vary. For example, the HE-SIG-B field is included in the HE PPDU format for multi-users (MUs), but the HE PPDU format for single users (SUs) does not include the HE-SIG-B. In addition, the HE trigger-based (TB) PPDU format does not include the HE-SIG-B, and the length of the HE-STF field may vary to 8us. 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 vary to 16us. For example, RL-SIG can be configured identically to L-SIG. The receiving STA can determine that the received PPDU is a HE PPDU or an EHT PPDU, described later, based on the presence of RL-SIG.

[0109] The EHT PPDU format may include the EHT MU (multi-user) PPDU 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 an L-SIG, but may include a U (universal)-SIG, an EHT-SIG, an EHT-STF, and an EHT-LTF following the RL-SIG.

[0110] The EHT MU PPDU in FIG. 7(e) corresponds to a PPDU that carries one or more data (or PSDUs) for one or more users. That is, the EHT MU PPDU can be used for both SU transmission and MU transmission. For example, the EHT MU PPDU can correspond to a PPDU for one receiving STA or multiple receiving STAs.

[0111] The EHT TB PPDU of Fig. 7(f) omits the EHT-SIG compared to the EHT MU PPDU. An 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.

[0112] The L-STF, L-LTF, L-SIG, RL-SIG, U-SIG (Universal SIGNAL), and EHT-SIG fields can be encoded and modulated so that even legacy STAs can attempt demodulation and decoding, and can be mapped based on a predetermined subcarrier frequency interval (e.g., 312.5 kHz). These can be referred to as pre-EHT modulated fields. Next, the EHT-STF, EHT-LTF, Data, and PE fields can 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 corresponding field, and can be mapped based on a predetermined subcarrier frequency interval (e.g., 78.125 kHz). These can be referred to as EHT modulated fields.

[0113] 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 modulation fields, and the HE-STF, HE-LTF, Data, and PE fields may be referred to as HE modulation fields. Additionally, in the VHT PPDU format, the L-STF, L-LTF, L-SIG, and VHT-SIG-A fields may be referred to as pre-VHT modulation fields, and the VHT STF, VHT-LTF, VHT-SIG-B, and Data fields may be referred to as VHT modulation fields.

[0114] The U-SIG included in the EHT PPDU format of FIG. 7 can be configured based on, for example, two symbols (e.g., two consecutive OFDM symbols). Each symbol (e.g., OFDM symbol) for the U-SIG can have a duration of 4 us, and the U-SIG can have a total duration of 8 us. Each symbol of the U-SIG can be used to transmit 26 bits of information. For example, each symbol of the U-SIG can be transmitted and received based on 52 data tones and 4 pilot tones.

[0115] U-SIGs can be configured in 20MHz units. For example, when an 80MHz PPDU is configured, the same U-SIG can be duplicated in 20MHz units. That is, four identical U-SIGs can be included in an 80MHz PPDU. When the bandwidth exceeds 80MHz, for example, for a 160MHz PPDU, the U-SIGs in the first 80MHz unit and the U-SIGs in the second 80MHz unit can be different.

[0116] For example, A uncoded bits may be transmitted via U-SIG, and a first symbol of U-SIG (e.g., a U-SIG-1 symbol) may transmit the first X bits of information out of a total A bits of information, and a second symbol of U-SIG (e.g., a U-SIG-2 symbol) may transmit the remaining Y bits of information out of a total A bits of information. The A bits of information (e.g., 52 uncoded bits) may include a CRC field (e.g., a field of 4 bits in length) and a tail field (e.g., a field of 6 bits in length). The tail field may be used to terminate the trellis of the convolutional decoder and may be set to 0, for example.

[0117] The A bit information transmitted by U-SIG can be divided into version-independent bits and version-dependent bits. For example, U-SIG can be included in a new PPDU format (e.g., UHR PPDU format) not shown in FIG. 7, and 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 can be the same, and some or all of the version-dependent bits can be different.

[0118] For example, the size of the version-independent bits of U-SIG can be fixed or variable. The version-independent bits can be assigned only to U-SIG-1 symbols, or to both U-SIG-1 symbols and U-SIG-2 symbols. The version-independent bits and the version-dependent bits can be called by various names, such as the first control bit and the second control bit.

[0119] For example, the version-independent bits of the U-SIG may include a 3-bit PHY version identifier, which may indicate the PHY version (e.g., EHT, UHR, etc.) of the transmitted and received PPDUs. The version-independent bits of the U-SIG may include a 1-bit UL / DL flag field. The first value of the 1-bit UL / DL flag field relates to UL communication, and the second value of the UL / DL flag field relates to DL communication. The version-independent bits of the U-SIG may include information about the length of a transmission opportunity (TXOP) and information about a BSS color ID.

[0120] For example, the version-dependent bits of the U-SIG may contain information that directly or indirectly indicates the type of PPDU (e.g., SU PPDU, MU PPDU, TB PPDU, etc.).

[0121] Information required for PPDU transmission and reception may be included in the U-SIG. For example, the U-SIG may further include information about bandwidth, information about the MCS technique applied to the non-legacy SIG (e.g., EHT-SIG or UHR-SIG), information indicating whether a dual carrier modulation (DCM) technique (e.g., a technique to achieve an effect similar to frequency diversity by reusing the same signal on two subcarriers) is applied to the non-legacy SIG, information about the number of symbols used for the non-legacy SIG, information about whether the non-legacy SIG is generated across the entire band, etc.

[0122] Some of the information required for transmitting and receiving a PPDU may be included in the U-SIG and / or the non-legacy SIG (e.g., EHT-SIG or UHR-SIG, etc.). For example, information about the type of the non-legacy LTF / STF (e.g., EHT-LTF / EHT-STF or UHR-LTF / UHR-STF, etc.), information about the length of the non-legacy LTF and the cyclic prefix (CP) length, information about the guard interval (GI) applicable to the non-legacy LTF, information about preamble puncturing applicable to the PPDU, information about resource unit (RU) 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.

[0123] Preamble puncturing may refer to the transmission of a PPDU in which no signal is present in one or more frequency units within the PPDU's bandwidth. 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 greater than a certain size.

[0124] 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 over at least one symbol, and each 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.).

[0125] Non-legacy SIGs, such as HE-SIG-B and EHT-SIG, may contain common fields and user-specific fields. Common and user-specific fields may be coded separately.

[0126] In some cases, common fields may be omitted. For example, in a compressed mode where non-OFDMA (orthogonal frequency multiple access) is applied, common fields may be omitted, and multiple STAs may receive PPDUs (e.g., data fields of PPDUs) over the same frequency band. In a non-compressed mode where OFDMA is applied, multiple users may receive PPDUs (e.g., data fields of PPDUs) over different frequency bands.

[0127] The number of user-specific fields can be determined based on the number of users. A single user block field can contain up to two user fields. Each user field can be associated with either MU-MIMO allocation or non-MU-MIMO allocation.

[0128] The common field may include CRC bits and Tail bits, the length of the CRC bits may be determined as 4 bits, and the length of the Tail bits may be determined as 6 bits and set to 000000. The common field may include RU allocation information. The RU allocation information may include information about the location of RUs to which multiple users (i.e., multiple receiving STAs) are allocated.

[0129] An RU can contain multiple subcarriers (or tones). RUs can be used when transmitting signals to multiple STAs based on OFDMA techniques. RUs can also be defined when transmitting signals to a single STA. Resources can be allocated on an RU basis for non-legacy STFs, non-legacy LTFs, and data fields.

[0130] Depending on the PPDU bandwidth, an applicable RU size can be defined. The RU may be defined identically or differently for the applicable PPDU format (e.g., HE PPDU, EHT PPDU, UHR PPDU, etc.). For example, in the case of an 80MHz PPDU, the RU arrangements of HE PPDU and EHT PPDU may be different. The applicable RU size, RU number, RU position, DC (direct current) subcarrier position and number, null subcarrier position and number, guard subcarrier position and number, etc. for each PPDU bandwidth can be referred to as a tone plan. For example, a tone plan for a wide bandwidth can be defined in the form of multiple repetitions of a low bandwidth tone plan.

[0131] RUs of different sizes can be defined, such as 26-ton RU, 52-ton RU, 106-ton RU, 242-ton RU, 484-ton RU, 996-ton RU, 2X996-ton RU, 4X996-ton RU, etc. A multiple RU (MRU) is distinguished from multiple individual RUs and corresponds to a group of subcarriers consisting of multiple RUs. For example, one MRU can be defined as 52+26-tons, 106+26-tons, 484+242-tons, 996+484-tons, 996+484+242-tons, 2X996+484-tons, 3X996-tons, or 3X996+484-tons. Additionally, multiple RUs constituting one MRU may or may not be consecutive in the frequency domain.

[0132] The specific size of an RU may be reduced or expanded. Therefore, the specific size of each RU (i.e., the number of corresponding tones) in the present disclosure is not limited and is exemplary. Furthermore, within a given bandwidth (e.g., 20, 40, 80, 160, 320 MHz, etc.) in the present disclosure, the number of RUs may vary depending on the RU size.

[0133] The names of each field in the PPDU formats of FIG. 7 are exemplary and the scope of the present disclosure is not limited by those names. Furthermore, the examples of the present disclosure can be applied not only to the PPDU format exemplified 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 formats of FIG. 7.

[0134] trigger frame

[0135] FIG. 8 is a drawing showing an exemplary format of a trigger frame to which the present disclosure can be applied.

[0136] A trigger frame may allocate resources for the transmission of one or more TB PPDUs and request the transmission of TB PPDUs. The trigger frame may also include other information required by the STA transmitting the TB PPDU in response. The trigger frame may include common information and a user information list field in the frame body.

[0137] The common information field may include information that is common to one or more TB PPDU transmissions requested by a trigger frame, such as trigger type, UL length, presence of a subsequent trigger frame (e.g., More TF), whether CS (channel sensing) is required, UL BW (bandwidth), etc. Fig. 12 illustrates an example of an EHT variant common information field format.

[0138] The 4-bit trigger type subfield can have values ​​from 0 to 15. Among them, the values ​​0, 1, 2, 3, 4, 5, 6, and 7 of the trigger type subfield are defined to correspond to basic, Beamforming Report Poll (BFRP), multi user-block acknowledgement request (MU-BAR), multi user-request to send (MU-RTS), Buffer Status Report Poll (BSRP), groupcast with retries (GCR) MU-BAR, Bandwidth Query Report Poll (BQRP), and NDP Feedback Report Poll (NFRP), respectively, and the values ​​8 to 15 are defined as reserved.

[0139] Among the common information, the trigger dependent common info subfield may include information that is optionally included based on the trigger type.

[0140] A special user info field may be included within the trigger frame. The special user info field does not contain user-specific information, but rather extended common information not provided in the common information field.

[0141] A user information list contains zero or more user information fields. Figure 12 illustrates an example of an EHT variant user information field format.

[0142] The AID12 subfield basically indicates that it is a user information field for an STA with the corresponding AID. In addition, if the AID12 field has a predetermined specific value, it may be utilized for other purposes, such as allocating a random access (RA)-RU, or being configured in the form of a special user information field. The special user information field is a user information field that does not contain user-specific information, but contains extended common information not provided in the common information field. For example, the special user information field can be identified by the AID12 value of 2007, and the special user information field flag subfield within the common information field can indicate whether the special user information field is included.

[0143] The RU allocation subfield can indicate the size and location of an RU / MRU. For this purpose, the RU allocation subfield can be interpreted together with the PS160 (primary / secondary 160MHz) subfield of the user information field, the UL BW subfield of the common information field, etc.

[0144] For example, the mapping of B7-B1 of the RU Allocation subfield can be defined together with the settings of the B0 and PS160 subfields of the RU Allocation subfield as shown in Table 1 below. Table 1 shows an example of encoding of the PS160 subfield and the RU Allocation subfield of the EHT Variant User Information Field.

[0145]

[0146]

[0147]

[0148] When B0 of the RU Allocation subfield is set to 0, it may indicate that the RU / MRU allocation is applied to the primary 80 MHz channel, and when its value is set to 1, it may indicate that the RU allocation is applied to the secondary 80 MHz channel of the primary 160 MHz. When B0 of the RU Allocation subfield is set to 0, it may indicate that the RU / MRU allocation is applied to the lower 80 MHz of the secondary 160 MHz, and when its value is set to 1, it may indicate that the RU allocation is applied to the upper 80 MHz of the secondary 160 MHz.

[0149] In the trigger frame RU allocation table of Table 1, the parameter N can be calculated based on the formula N=2*X1+X0. For a bandwidth of 80 MHz or less, the values ​​of PS160, B0, X0, and X1 can be set to 0. For a bandwidth of 160 MHz and a bandwidth of 320 MHz, the values ​​of PS160, B0, X0, and X1 can be set as shown in Table 2. These settings represent the absolute frequency order for the primary and secondary 80 MHz and 160 MHz channels. The order from left to right represents the order from low frequency to high frequency. The primary 80 MHz channel is represented as P80, the secondary 80 MHz channel is represented as S80, and the secondary 160 MHz channel is represented as S160.

[0150]

[0151] CCMP(Counter Mode with cipher-block chaining message authentication code protocol)

[0152] CCMP provides confidentiality, authentication, integrity, and replay protection for data.

[0153] CCMP is based on the CCM of the AES encryption algorithm, which combines Counter Mode (CTR) for data confidentiality and Cipher-Block Chaining Message Authentication Code (CBC-MAC) for authentication and integrity. CCM can provide integrity protection for both the MPDU data field and selected portions of the MAC header (i.e., the IEEE 802.11 MPDU header). In this regard, the AES processing used within CCMP can utilize AES with a 128-bit key (CCMP-128) or a 256-bit key (CCMP-256).

[0154] In this regard, when CCMP is selected as the robust security network (RSN) pairwise cipher and management frame protection is negotiated, individually addressed robust management frames and group addressed action frames need to be protected with CCMP.

[0155] Figure 9 illustrates a CCMP MPDU structure applicable to the present disclosure.

[0156] Referring to FIG. 9, a CCMP MPDU may include a MAC header, a CCMP header, data (PDU), a MIC field, and an FCS field.

[0157] Specifically, the CCMP header can be composed of PN information, key ID information, etc.

[0158] With respect to CCMP MPDUs, encryption can be applied to the data (PDU) and MIC fields.

[0159] Figure 10 illustrates a CCMP encryption encapsulation process that can be applied to the present disclosure.

[0160] Referring to Figure 10, CCMP can encrypt the frame body field of a plaintext MPDU and encapsulate the resulting cipher text using the following steps.

[0161] 1) By incrementing the PN (packet number), a new non-zero PN can be obtained for each MPDU. This prevents the PN from being repeated for the same temporal key.

[0162] 2) Additional authentication data (AAD) for CCM can be constructed using fields in the MPDU header. The CCM algorithm can provide integrity protection for the fields included in the AAD. MPDU header fields that may change during retransmission can be muted by setting them to known values ​​during AAD calculation and masking them out.

[0163] 3) A CCM nonce can be constructed from the priority value of an MPDU whose PN, A2, and A2 are MPDU address 2. If the Type field of the Frame Control field is 10 (i.e., a data frame) and a QoS Control field is present in the MPDU header, the priority value of the MPDU can be the same as the value of the TID subfield of the QoS Control field (e.g., bits 0 to 3 of the QoS Control field). If the Type field of the Frame Control field is 00 (i.e., a management frame) and the frame is QMF, the priority value of the MPDU can be the same as the value in the ACI subfield of the Sequence Number field. Otherwise, the priority value of the MPDU can be a fixed value of 0.

[0164] 4) CCMP header can be configured.

[0165] 5) The temporary key, AAD, CCM nonce, and MPDU data can be used to generate the ciphertext and encrypted MIC. This step may be referred to as CCM originator processing.

[0166] 6) As illustrated in FIG. 9, an MPDU with CCMP-based encryption applied can be constructed by combining an original MPDU header (e.g., MAC header), a CCMP header, encrypted data, and an encrypted MIC.

[0167] Figure 11 illustrates a CCMP decapsulation process applicable to the present disclosure.

[0168] Referring to Figure 11, CCMP can decrypt the frame body field of a ciphertext MPDU and decapsulate a plaintext MPDU using the following steps.

[0169] 1) The encrypted MPDU can be parsed to form the AAD and nonce values.

[0170] 2) MIC can be extracted for use in CCM integrity check.

[0171] 3) In CCM receiver processing, the temporary key, AAD, nonce, encrypted MIC, and MPDU ciphertext data can be used to recover the MPDU plaintext data and verify the integrity of the AAD and MPDU plaintext data.

[0172] 4) A plain text MPDU can be constructed by concatenating the received MPDU header and the MPDU plain text data processed by the CCM receiver.

[0173] 5) Decryption processing can prevent replay of an MPDU by checking that the PN of the MPDU is greater than a replay counter maintained for the session and TID (for data frames) or ACI (for QMF).

[0174] In relation to the CCMP-based encryption / decryption described above, AAD can be constructed based on the MAC header (i.e., the original MPDU header).

[0175] Galois / Counter Mode protocol (GCMP)

[0176] GCMP provides confidentiality, authentication, integrity, and replay protection for data.

[0177] GCMP is based on the GCM of the AES encryption algorithm, which can provide integrity protection for both the MPDU data field and selected portions of the MAC header (i.e., the IEEE 802.11 MPDU header). In this regard, the AES processing used within GCMP can use AES based on a 128-bit key (GCMP-128) or a 256-bit key (GCMP-256).

[0178] In this regard, when GCMP is selected as the robust security network (RSN) pairwise cipher and management frame protection is negotiated, individually addressed robust management frames and group addressed action frames need to be protected with GCMP.

[0179] Figure 12 illustrates a GCMP MPDU structure applicable to the present disclosure.

[0180] Referring to FIG. 12, a GCMP MPDU may include a MAC header, a GCMP header, data (PDU), a MIC field, and an FCS field.

[0181] Specifically, the GCMP header may consist of PN information, key ID information, etc.

[0182] With respect to GCMP MPDUs, encryption can only be applied to data (PDUs).

[0183] Figure 13 illustrates a GCMP encryption encapsulation process that can be applied to the present disclosure.

[0184] Referring to Figure 13, GCMP can encrypt the frame body field of a plaintext MPDU and encapsulate the resulting cipher text using the following steps.

[0185] 1) By incrementing the PN (packet number), a new non-zero PN can be obtained for each MPDU. This prevents the PN from being repeated for the same temporal key.

[0186] 2) Additional authentication data (AAD) for GCM can be constructed using fields in the MPDU header. The GCM algorithm can provide integrity protection for the fields included in the AAD. MPDU header fields that may change during retransmission can be muted by setting them to known values ​​during AAD calculation and masking them out.

[0187] 3) GCM nonce can be configured.

[0188] 4) CCMP header can be configured.

[0189] 5) The temporary key, AAD, GCM nonce, and MPDU data can be used to generate the ciphertext and MIC. This step may be referred to as GCM originator processing.

[0190] 6) As illustrated in FIG. 12, an MPDU with GCMP-based encryption applied can be constructed by combining an original MPDU header (e.g., MAC header), a GCMP header, encrypted data, and a MIC.

[0191] Figure 14 illustrates a GCMP decapsulation process applicable to the present disclosure.

[0192] Referring to Figure 14, GCMP can decrypt the frame body field of a ciphertext MPDU and decapsulate a plaintext MPDU using the following steps.

[0193] 1) The encrypted MPDU can be parsed to form the AAD and nonce values.

[0194] 2) MIC can be extracted for use in GCM integrity check.

[0195] 3) In GCM receiver processing, the temporary key, AAD, nonce, MIC, and MPDU ciphertext data can be used to recover the MPDU plaintext data and verify the integrity of the AAD and MPDU plaintext data.

[0196] 4) A plain text MPDU can be constructed by concatenating the received MPDU header and the MPDU plain text data processed by the GCM receiver.

[0197] 5) Decryption processing can prevent replay of an MPDU by checking that the PN of the MPDU is greater than a replay counter maintained for the session and TID (for data frames) or ACI (for QMF).

[0198] In relation to the GCMP-based encryption / decryption described above, AAD can be constructed based on the MAC header (i.e., the original MPDU header).

[0199] A method to support CCMP / GCMP-based protection for control frames.

[0200] In the case of existing wireless LAN systems, encryption / decryption based on Temporal Key Integrity Protocol (TKIP) / CCMP / GCMP can be performed / applied using a pairwise transient key (PTK) for individually addressed data frames (e.g., unicast-based data frames) and management frame(s). In addition, encryption / decryption based on TKIP / CCMP / GCMP can be performed / applied using a group temporal key (GTK) for group addressed frames (e.g., broadcast-based data frames). That is, CCMP / GCMP is a security protocol that performs encryption / decryption, and a TK based on PTK can be used for a single-user (SU), and a TK based on GTK can be used for a multi-user (MU). CCMP / GCMP can ensure confidentiality and integrity for data frames and management frame(s).

[0201] Additionally, for group-addressed management frames(es), BIP-based integrity check can be performed using IGTK (integrity group temporal key). In particular, for beacon frames, BIP-based integrity check can be performed using BIGTK (beacon integrity group temporal key). In the case of BIP, a TK based on IGTK / BIGTK is used to generate a message integrity code (MIC) for the frame body of the corresponding data frame, and an integrity check can be performed based on this. That is, unlike CCMP / GCMP, BIP can only guarantee the integrity of data frames and management frames(es).

[0202] The way MPDUs are constructed based on CCMP and GCMP and the way MMPDUs (management MPDUs) are constructed based on BIP have the following differences:

[0203] First, in the case of CCMP / GCMP, the transmitting STA encrypts the data portion using CCM / GCM and transmits the encrypted data, and the receiving STA can decrypt the received encrypted data. In contrast, in the case of BIP, the transmitting STA does not encrypt the data portion and can perform the corresponding protocol to generate an MIC for integrity verification of the data in the frame body.

[0204] Next, for CCMP / GCMP, the MPDU can be composed and transmitted and received in the following order: MAC header, CCMP / GCMP header, encrypted data, MIC (encrypted MIC in case of CCMP), and FCS. In contrast, for BIP, the MPDU can be composed and transmitted and received in the following order: MAC header, management frame body including MME (management MIC element), and FCS. Here, since the MME takes the role of CCMP / GCMP header, it can include information on Key ID field, IPN / BIPN, and MIC.

[0205] As previously mentioned, protection is supported for management frames, including data frames and beacon frames, among group-addressed frames. However, protection is not supported for control frames, and thus control frames are transmitted and received without any encryption / decryption and / or integrity check protocols applied.

[0206] Among control frames, a trigger frame is a frame that contains information that allocates specific RUs, specific bandwidths, etc. for data transmission and reception for multiple STAs. If the information contained in the trigger frame is exposed to a third-party STA (e.g., an attack STA), the data transmission and reception capabilities between the transmitting STA and the receiving STA may be reduced, or this may result in waste of power / medium.

[0207] Taking these points into consideration, the present disclosure proposes a security technology for ensuring confidentiality and integrity of trigger frames transmitted and received between a transmitting STA and a receiving STA.

[0208] The values / names proposed in this disclosure may be changed, and the scope of this disclosure is not limited thereto. Furthermore, the STA in this disclosure may include a non-AP STA and an AP STA.

[0209] Additionally, in the description of the present disclosure, it is assumed that all receiving STAs that receive a trigger frame according to the present disclosure transmitted by an AP, which is a transmitting STA, are UHR STAs (and / or beyond UHR STAs). That is, if a pre-UHR STA (e.g., an EHT / HE STA, etc.) receives a trigger frame configured according to the proposed method of the present disclosure, an error may occur during decoding of the trigger frame.

[0210] Additionally, although the present disclosure describes a security technology for a trigger frame among control frames as a representative example, the proposed method of the present disclosure can be extended and applied to other types of control frames other than trigger frames.

[0211] In the present disclosure, performing confidentiality and integrity checks on trigger frames can be interpreted as extending and applying CCMP / GCMP to trigger frames. In this regard, additional provisions for control frames may be defined for the previously defined CCMP / GCMP, or a separate protocol based on CCMP / GCMP for confidentiality and integrity checks of control frames may be newly defined.

[0212] Below, methods for supporting / performing protection, i.e., confidentiality and integrity checks, for trigger frames are described through specific examples.

[0213] Example 1

[0214] This embodiment is about a trigger frame configuration method to support the aforementioned protection.

[0215] In this regard, the length of the CCMP / GCMP header and information (e.g., key ID, IPN / BIPN, MIC) configured within the MIC added to the chip text (i.e., encrypted text) after application of CCMP / GCMP is not limited to the previously defined values.

[0216] It is not limited to what is shown in Fig. 10. For example, in the case of the key ID field, the key ID indicating GTK has a length of 2 bits, but the key ID indicating IGTK or BIGTK can have a length of 2 octets. In addition, in the case of the MIC field, the length can be 8 octets, 16 octets, 64 octets, etc. Additionally, the length can be changed by additionally applying the MIC value to a separate function.

[0217] A trigger frame for applying protection according to the present disclosure may be configured based on one or more of the formats described below.

[0218] Example 1-1

[0219] To support protection for trigger frames, a format can be configured that applies CCMP to the common information field and user information list field included in the trigger frame.

[0220] The format may be for performing encryption / decryption on the common information field and the user information list field(s) (i.e., one or more user information fields) within the trigger frame.

[0221] Specifically, the transmitting STA may perform CCMP encryption on the common information field and the user information list field(s) using a key negotiated / shared with the receiving STA. During the encryption process, additional authentication data (AAD) may be configured using the frame control field, duration field, receiver address (RA) field, and / or transmitter address (TA) field, which are the front part of the MPDU format (e.g., MPDU header or MAC header).

[0222] For CCMP, the MIC value calculated based on the common information field and the user information list field is configured in encrypted text form together with the common information field and the user information list field.

[0223] FIG. 15 illustrates a CCMP MPDU format according to an embodiment of the present disclosure.

[0224] Referring to FIG. 15, the CCMP MPDU format may be composed of a frame control field, an interval field, an RA field, a TA field, a CCMP header field, encrypted text, padding, and an FCS in that order. This configuration is merely an example, and the scope of the present disclosure is not limited thereto.

[0225] In this regard, the CCMP header field may include information about PN (packet number) related values ​​(e.g., PN0, PN1, PN2, PN3, PN4, PN5, etc.) and / or key ID.

[0226] As mentioned above, when CCMP is applied, the common information field, the user information list field, and the MIC information can be included in the CCMP MPDU format in the form of encrypted text. That is, CCMP-based encryption can be applied to the entire frame body and MIC information of the trigger frame before encryption.

[0227] Example 1-2

[0228] To support protection for trigger frames, a format can be configured that applies GCMP to the common information field and user information list field included in the trigger frame.

[0229] The format may be for performing encryption / decryption on the common information field and the user information list field(s) (i.e., one or more user information fields) within the trigger frame.

[0230] Specifically, the transmitting STA may perform GCMP encryption on the common information field and the user information list field(s) using a key negotiated / shared with the receiving STA. During the encryption process, additional authentication data (AAD) may be configured using the frame control field, duration field, receiver address (RA) field, and / or transmitter address (TA) field, which are the front part of the MPDU format (e.g., MPDU header or MAC header).

[0231] For GCMP, the MIC value calculated based on the common information field and the user information list field is not encrypted, unlike the CCMP described above.

[0232] FIG. 16 illustrates a GCMP MPDU format according to an embodiment of the present disclosure.

[0233] Referring to FIG. 16, the GCMP MPDU format may be composed of a frame control field, an interval field, an RA field, a TA field, a GCMP header field, encrypted text, an MIC field, padding, and an FCS in that order. This configuration is merely an example, and the scope of the present disclosure is not limited thereto.

[0234] In this regard, the GCMP header field may include information about PN (packet number) related values ​​(e.g., PN0, PN1, PN2, PN3, PN4, PN5, etc.) and / or key ID.

[0235] As mentioned above, when GCMP is applied, the common information field and the user information list field can be included in the GCMP MPDU format in the form of encrypted text. That is, GCMP-based encryption can be applied to the entire frame body of the trigger frame prior to encryption.

[0236] Additionally, with respect to a trigger frame supporting protection according to the present disclosure, a transmitting STA and a receiving STA(s) may share information with each other regarding whether encryption (i.e., encryption based on CCMP or GCMP) for the trigger frame is supported. The information may be shared via a specific element (e.g., an Extended RSN element (RSNXE)) during a discovery process (e.g., a beacon frame, a probe response frame, etc.) and / or a (re)association process (e.g., a (re)association request frame, a (re)association response frame, etc.).

[0237] In this regard, whether CCMP or GCMP application to trigger frames is supported can be shared by utilizing reserved bits in existing elements (e.g., RSNXE) or by defining new (sub)fields in new elements. For example, a 1-bit protected trigger support (sub)field can be newly defined, and a value of 1 can be defined to mean / indicate that CCMP or GCMP application to trigger frames is supported, and a value of 0 can be defined to mean / indicate that CCMP or GCMP application to trigger frames is not supported.

[0238] If both the transmitting STA and the receiving STA support encryption and support applying encryption to the trigger frame, the two STAs can perform encryption application to the trigger frame. Conversely, if the transmitting STA and the receiving STA support encryption but do not support applying encryption to the trigger frame, the two STAs may not perform encryption to the trigger frame. Additionally, when encrypting the trigger frame, the cipher suite (e.g., CCMP-128, CCMP-256, GCMP-128, GCMP-256, etc.) agreed upon by the transmitting STA and the receiving STA during the negotiation process may be used identically. Alternatively, in order to encrypt the trigger frame, the transmitting STA and the receiving STA may negotiate an additional / separate cipher suite for the trigger frame.

[0239] Additionally or alternatively, in the case of existing wireless LAN systems, the transmitting STA and the receiving STA do not perform encryption / decryption operations based on CCMP or GCMP for trigger frames, which are a type of control frame. In this regard, the protected frame subfield of the frame control field in the MAC header is set to reserved for control frames.

[0240] In contrast, when the common information field and / or the user information list field of the trigger frame is encrypted / decrypted based on CCMP or GCMP according to the method proposed in the present disclosure, the value of the protected frame subfield in the frame control field of the trigger frame is set to 1. Based on this, the receiving STA can recognize that the common information field and / or the user information list field in the trigger frame is encrypted through the value of the protected frame subfield. In this regard, when encrypting the trigger frame, the cipher suite (e.g., CCMP-128, CCMP-256, GCMP-128, GCMP-256, etc.) agreed upon by the transmitting STA and the receiving STA during the negotiation process can be used identically. Alternatively, in order to encrypt the trigger frame, the transmitting STA and the receiving STA may negotiate an additional / separate cipher suite for the trigger frame.

[0241] Additionally or alternatively, information regarding whether encryption (i.e., CCMP or GCMP-based encryption) for trigger frames is supported and in which format the CCMP / GCMP MPDU format is configured among the methods proposed in the present disclosure may be shared between the transmitting STA and the receiving STA. In this regard, for sharing the information, reserved bits in existing elements (e.g., RSNXE), reserved bits in the UHR variant common information field, and / or reserved bits in the special user information field may be utilized, or a new (sub)field in a new element (e.g., a protected trigger mode (sub)field) may be defined. At this time, the method of encrypting / decrypting the trigger frame may be the same as the cipher suite (e.g., CCMP-128, CCMP-256, GCMP-128, GCMP-256, etc.) agreed upon during the negotiation process between the transmitting STA and the receiving STA, or an additional / separate cipher suite for the trigger frame may be negotiated.

[0242] The (sub)field may be included in a beacon frame by a transmitting STA or in a data frame by a receiving STA not only during the (re)association process but also during the data transmission and reception process. For example, setting the value of the protected trigger mode (sub)field to 0 may mean / indicate that CCMP or GCMP-based encryption is not applied to the trigger frame. Conversely, setting the value of the protected trigger mode (sub)field to 1 or more may mean / indicate that CCMP or GCMP-based encryption is applied to the trigger frame.

[0243] As a specific example, when the protected trigger mode (sub)field is set to a value of 1 or more, the value of the protected trigger mode (sub)field may be defined as in Table 3 below. Table 3 is exemplary, and at least one of the values ​​described in Table 3 may be applied / defined, and specific values ​​may be set / defined differently from the example.

[0244] Meaning of the value of the Protected Trigger Mode (Sub) Field 0 CCMP / GCMP not applied to the trigger frame 1 Trigger frame configuration based on Example 1-1 2 Trigger frame configuration based on Example 1-2......

[0245] Additionally or alternatively, the reserved bits present in front of the key ID information (i.e., the key ID octet) in the CCMP header and / or GCMP header may be utilized as a protected trigger mode (sub)field to share information about whether encryption (i.e., CCMP or GCMP-based encryption) for the trigger frame is supported and in which format the CCMP / GCMP MPDU format is configured among the methods proposed in the present disclosure. In this case, the method of encrypting / decrypting the trigger frame may use the same cipher suite (e.g., CCMP-128, CCMP-256, GCMP-128, GCMP-256, etc.) agreed upon during the negotiation process between the transmitting STA and the receiving STA, or an additional / separate cipher suite for the trigger frame may be negotiated.

[0246] The (sub)field may be included in a data frame transmitted by a transmitting STA to a receiving STA during a data transmission / reception process. For example, setting the value of the protected trigger mode (sub)field to 0 may mean / indicate that CCMP or GCMP-based encryption is not applied to the trigger frame. Conversely, setting the value of the protected trigger mode (sub)field to 1 or greater may mean / indicate that CCMP or GCMP-based encryption is applied to the trigger frame.

[0247] As a specific example, when the protected trigger mode (sub)field is set to a value of 1 or more, the value of the protected trigger mode (sub)field may be defined as shown in Table 4 below. Table 4 is exemplary, and at least one of the values ​​described in Table 4 may be applied / defined, and specific values ​​may be set / defined differently from the example.

[0248] Meaning of the value of the Protected Trigger Mode (Sub) Field 0 CCMP / GCMP not applied to the trigger frame 1 Trigger frame configuration based on Example 1-1 2 Trigger frame configuration based on Example 1-2......

[0249] Example 2

[0250] This embodiment relates to a method for generating an MIC for CCMP / GCMP transmission / reception in relation to the application of encryption to the trigger frame described above.

[0251] In the case of a trigger frame, the type of the trigger frame to be transmitted and received can be indicated based on the value of the trigger type subfield in the common information field. Depending on the indicated value, the receiving STA can determine whether the trigger frame is an individually addressed frame or a group addressed frame. In addition, the receiving STA can determine whether the trigger frame is an individually addressed frame or a group addressed frame based on the information in the RA field in the trigger frame.

[0252] In this regard, when applying CCMP or GCMP to a trigger frame, the key used to calculate the MIC value may be used differently depending on whether it is an individually addressed frame or a group addressed frame.

[0253] For example, for individually addressed data frames, MIC value calculation may be performed using a TK based on a PTK generated identically between the transmitting STA and the receiving STA. Conversely, for group addressed data frames, MIC value calculation may be performed using a TK based on a GTK shared by the transmitting STA with the receiving STA.

[0254] For existing CCMP / GCMP (e.g., CCMP / GCMP applied to data frames / management frames), it is not possible to utilize CCMP and GCMP based on IGTK or BIGTK. In contrast, the present disclosure assumes that CCMP and / or GCMP based on PTK / GTK / IGTK / BIGTK are possible.

[0255] Below, we specifically describe how keys are used to calculate and verify MIC values ​​for individually addressed trigger frames and / or group addressed trigger frames.

[0256] First, for individually addressed trigger frames, the MIC value can be calculated / verified as follows.

[0257] The transmitting STA and the receiving STA can calculate the MIC value using the TK based on the PTK generated identically during the 4-way handshake process. For example, in relation to the application of BIP to a trigger frame, the transmitting STA and the receiving STA can equally utilize the PTK generated in relation to the protection of the data frame during the 4-way handshake process, or can utilize a (new) PTK generated / agreed / shared identically between them in relation to the protection of the trigger frame during the 4-way handshake process.

[0258] Alternatively, the transmitting STA and the receiving STA may calculate the MIC value using a TK based on a new PTK for individually addressed trigger frames shared during the 4-way handshake process. In this regard, the new PTK may be referred to as a Trigger PTK (TPTK), and the transmitting STA may generate and share a different TPTK for each receiving STA. That is, different TPTKs may be shared for receiving STA 1 and receiving STA 2. In addition, information about the TPTK and information related to a cipher suite that can use the TPTK may be shared between the transmitting STA and the receiving STA through a new key data element (KDE) for the TPTK (e.g., TPTK KDE).

[0259] If the receiving STA recognizes / verifies the key (e.g., TPTK) for protecting the trigger frame (and / or received the key from the transmitting STA), the receiving STA can perform an MIC check on the trigger frame based on the key. Otherwise, the receiving STA can perform an MIC check on the trigger frame based on a key (e.g., PTK) previously shared with the transmitting STA.

[0260] Next, for group addressed trigger frames, the MIC value can be calculated / verified as follows.

[0261] A transmitting STA can generate an IGTK or a BIGTK and share it with a receiving STA during a 4-way handshake process, and the transmitting STA and the receiving STA can calculate an MIC value using a TK based on the IGTK or the BIGTK.

[0262] Alternatively, the transmitting STA can generate a GTK and share it with the receiving STA during the 4-way handshake process, and the transmitting STA and the receiving STA can calculate the MIC value using a TK based on the GTK.

[0263] Alternatively, the transmitting STA may generate a new GTK for the group-addressed trigger frame and share it with the receiving STA during the 4-way handshake process, and the transmitting STA and the receiving STA may calculate an MIC value using a TK based on the new GTK. Here, the new GTK may be referred to as a trigger broadcast GTK (TBGTK), and the transmitting STA may share a TBGTK of the same value with the receiving STAs. That is, the AP may generate and share the same TBGTK with the STAs associated with it. In addition, information about the TBGTK and information related to a cipher suite that can use the TBGTK may be shared between the transmitting STA and the receiving STA through the new KDE for the TBGTK (e.g., the TBGTK KDE).

[0264] If the receiving STA has received a key (e.g., TBGTK) for protecting the trigger frame from the transmitting STA, the receiving STA can perform an MIC check on the trigger frame based on the key. Otherwise, the receiving STA can perform an MIC check on the trigger frame based on a key (e.g., IGTK or BIGTK) previously shared with the transmitting STA.

[0265] Example 3

[0266] This embodiment is about a specific method for performing protection (i.e., encryption and integrity check) on a trigger frame based on the trigger frame configuration proposed in the present disclosure.

[0267] First, if the trigger frame is a group-addressed trigger frame, the trigger frame configuration proposed in the present disclosure can be used as in the following examples.

[0268] For example, in the case of the trigger frame configuration described in Example 1-1 (e.g., see FIG. 15), the transmitting STA and / or the receiving STA may perform encryption / decryption via CCMP using GTK, IGTK, BIGTK, or TBGTK for the common information field and the user information list field, and derive the MIC value.

[0269] For another example, in the case of the trigger frame configuration described in Example 1-2 (e.g., see FIG. 16), the transmitting STA and / or the receiving STA may perform encryption / decryption via GCMP using GTK, IGTK, BIGTK, or TBGTK for the common information field and the user information list field, and derive the MIC value.

[0270] Next, if the trigger frame is an individually addressed trigger frame, the trigger frame configuration proposed in the present disclosure can be used as in the following examples.

[0271] For example, in the case of the trigger frame configuration described in Example 1-1 (e.g., see FIG. 15), the transmitting STA and / or the receiving STA may perform encryption / decryption via CCMP using the PTK or TPTK described above for the common information field and the user information list field, and derive the MIC value.

[0272] For another example, in the case of the trigger frame configuration described in Example 1-2 (e.g., see FIG. 16), the transmitting STA and / or the receiving STA may perform encryption / decryption via GCMP using the PTK or TPTK described above for the common information field and the user information list field, and derive the MIC value.

[0273] Based on the methods proposed in this disclosure, protection for trigger frames can be performed as follows.

[0274] For the example situations described below, it is assumed that the transmitting STA and the receiving STA(s) support the use of trigger frames over CCMP or GCMP via the protected trigger support (sub)field and / or share the configuration method of the CCMP / GCMP MPDU format of the trigger frame via the protected trigger mode (sub)field.

[0275] A receiving STA can configure an AAD for a trigger frame based on information in the MAC header of an MPDU received from a transmitting STA (e.g., frame control field, interval field, RA field, TA field, etc.). Thereafter, the receiving STA can decode the MSDU using the AAD.

[0276] A receiving STA can obtain a plaintext MPDU and an MIC value based on the MPDU, which is the result of decryption based on the AAD and CCMP or GCMP configured by the receiving STA for the trigger frame. At this time, the receiving STA can derive the MIC value by performing the same encryption process for the MPDU as the transmitting STA.

[0277] Thereafter, the receiving STA can compare the derived MIC value with the MIC value transmitted by the transmitting STA (e.g., MIC information included in the CCMP MPDU format or the GCMP MPDU format). If the two MIC values ​​are the same, the receiving STA can follow the information in the acquired plaintext MPDU. Conversely, if the two MIC values ​​are not the same, the receiving STA can recognize that at least one piece of information in the acquired plaintext MPDU has been modified by a third party STA (e.g., an attacking STA) or has been damaged during transmission and reception, and can discard it.

[0278] The operation of an STA supporting / performing protection for a trigger frame according to an embodiment of the present disclosure may be as shown in FIGS. 17 and 18.

[0279] FIG. 17 illustrates the operation of a transmitting STA that supports protection for a trigger frame according to the present disclosure.

[0280] Referring to FIG. 17, a transmitting STA may share with a receiving STA information including whether it supports protection (e.g., encryption / decryption and integrity check) for a trigger frame (S1710).

[0281] At this time, if both the transmitting STA and the receiving STA(s) apply security to the trigger frame, the transmitting STA may generate and share key(s) used for integrity check of the trigger frame (S1720). For example, depending on the type of the trigger frame, the key(s) may include a key for individually addressed frames (e.g., PTK or TPTK, collectively referred to as PTK) or a key for group addressed frames (e.g., GTK, IGTK, BIGTK, or TBGTK, collectively referred to as GTK).

[0282] Based on the key(s), the transmitting STA can construct a trigger frame including a result value / information (e.g., encrypted text) based on CCMP or GCMP, and transmit the trigger frame to the receiving STA(s) (S1730).

[0283] In relation to the above-described process, the transmitting STA may share / discuss in advance with the receiving STA information on how to configure the CCMP / GCMP MPDU format within the trigger frame to be transmitted, or may include the information in the trigger frame and transmit it.

[0284] FIG. 18 illustrates the operation of a receiving STA that supports protection for a trigger frame according to the present disclosure.

[0285] Referring to FIG. 18, the receiving STA can share with the transmitting STA information including whether it supports protection (e.g., encryption / decryption and integrity check) for the trigger frame (S1810).

[0286] At this time, if the key(s) used for integrity verification of the transmitting STA and the trigger frame are shared, the receiving STA can assume that a protection method has been applied to the trigger frame transmitted by the transmitting STA (S1820).

[0287] In this regard, the transmitting STA and the receiving STA may generate / negotiate / share the same key information (e.g., PTK / GTK, etc.) through a key generation process, or key information generated by the transmitting STA may be transmitted to the receiving STA.

[0288] For example, a receiving STA may receive a trigger frame transmitted from a transmitting STA and recognize that CCMP or GCMP has been applied based on information related to the pre-shared key(s) and / or the composition of the CCMP / GCMP MPDU format.

[0289] Based on this, when a trigger frame is received, the receiving STA can perform decryption and integrity check on the trigger frame using pre-shared / generated / agreed key(s) (e.g., PTK / GTK, etc.) (S1830).

[0290] Below, FIGS. 19 and 20 illustrate operations performed by an STA according to the proposed method of the present disclosure described above. In FIGS. 19 and 20 , the second STA may correspond to an AP / transmitting STA, and the first STA may correspond to a non-AP STA / receiving STA coupled to an AP.

[0291] FIG. 19 is a diagram illustrating an example of a method performed by a first STA according to the present disclosure.

[0292] Referring to FIG. 19, the first STA can check key information related to protection for the control frame (S1910).

[0293] For example, a control frame may correspond to a trigger frame for triggering transmission and reception of data frames with a second STA. In this case, key information related to protection for the control frame may be configured independently from key information for protecting data triggered by the control frame.

[0294] Here, protection for the control frame may be based on encryption / decryption and integrity checking utilizing CCMP or GCMP as described above in the present disclosure.

[0295] In this regard, the first STA may negotiate / share / generate key information (related to the control frame) with the second STA in advance through a four-way handshake process. Additionally or alternatively, the first STA may also receive key information generated from the second STA.

[0296] For example, if the control frame corresponds to an individually addressed control frame, the key information may include a pairwise transient key (PTK) (e.g., TPTK, etc.) for the first STA and the second STA. On the other hand, if the control frame corresponds to a group addressed control frame, the key information may include a group temporal key (GTK) (e.g., TBGTK, etc.) for the first STA and the second STA.

[0297] The first STA can receive a control frame including encrypted information (e.g., encrypted text) based on a specific encryption protocol from the second STA (S1920).

[0298] In this regard, the encrypted information may be configured based on encryption of a common information field and one or more user information fields (e.g., a user information list field) within the control frame.

[0299] For example, a specific encryption protocol may correspond to CCMP or GCMP as described above in the present disclosure. In this regard, CCMP-128 or CCMP-256 may be used as a cipher suite for the CCMP, and GCMP-128 or GCMP-256 may be used as a cipher suite for the GCMP.

[0300] Additionally, the control frame may include message integrity code (MIC) information calculated based on the aforementioned key information. In this case, if a specific encryption protocol corresponds to CCMP, the encrypted information included in the control frame may be configured by additionally applying encryption to the MIC information. That is, in the case of an encrypted control frame based on CCMP, a common information field, one or more user information fields, and ciphertext with encryption applied to the MIC may be included.

[0301] Additionally, the control frame may include a CCMP header or a GCMP header, which includes a first field for a key identifier (ID) and a second field for a packet number. Here, the CCMP header or the GCMP header may further include information indicating an MPDU format (e.g., the MPDU format of FIGS. 15 and 16) according to the type of a specific encryption protocol within the control frame.

[0302] Thereafter, the first STA can perform decryption of the encrypted information and integrity check on the corresponding control frame based on the verified key information (S1930).

[0303] Additionally or alternatively, with respect to the procedure described above, information indicating whether protection for a control frame is supported may be transmitted and received between the first STA and the second STA. For example, the information indicating whether protection for a control frame is supported may be transmitted and received through at least one of a frame during a discovery process (e.g., a beacon frame, a probe request frame, a probe response frame, etc.), a frame during a (re)association process (e.g., a (re)association request frame, a (re)association response frame, etc.), or a corresponding control frame.

[0304] Additionally or alternatively, in connection with the above-described procedure, when the above-described specific encryption protocol is applied to a control frame, the protected frame subfield within the frame control field included in the control frame may be set to a predefined specific value (e.g., 1).

[0305] Additionally or alternatively, in relation to the procedure described above, information indicating an MPDU format (e.g., the MPDU format of FIGS. 15 and 16) according to the type of a specific encryption protocol may be transmitted and received in advance between the first STA and the second STA.

[0306] The method described in the example of FIG. 19 can be performed by the first device (100) of FIG. 1. That is, the first STA of FIG. 19 can be implemented as the first device (100). For example, one or more processors (102) of the first device (100) of FIG. 1 can be configured to verify key information related to protection for a control frame, receive a control frame including encrypted information based on a specific encryption protocol from a second STA, and perform decryption of the encrypted information and an integrity check on the control frame based on the key information.

[0307] In this regard, one or more processors (102) can recognize whether the received trigger frame has been applied to security based on information previously shared with the transmitting STA (e.g., PTK / GTK for performing encryption / decryption, which encryption / decryption algorithm to use, which field to encrypt / decrypt, etc.) based on the decoded data, and can perform decryption and integrity check by applying CCMP or GCMP. As a specific example, one or more processors (102) can parse a MAC frame obtained through PHY decoding of a DATA field of a PPDU received through one or more transceivers (106). One or more processors (102) can apply CCMP or GCMP to a cipher text (cipher txt) portion of the parsed MAC frame to obtain plain text (plain txt) and an MIC value, and can perform an integrity check by comparing the MIC value with the MIC value transmitted by the transmitting STA.

[0308] Furthermore, one or more memories (104) of the first device (100) may store commands for performing the method described in the example of FIG. 19 or the examples described below when executed by one or more processors (102).

[0309] FIG. 20 is a drawing for explaining an example of a method performed by a second STA according to the present disclosure.

[0310] Referring to FIG. 20, the second STA can check key information related to protection for the control frame (S2010).

[0311] Here, protection for the control frame may be based on encryption / decryption and integrity checking utilizing CCMP or GCMP as described above in the present disclosure.

[0312] Thereafter, the second STA can configure a trigger frame including encrypted information based on the key information and a specific encryption protocol (S2020).

[0313] In this regard, the encrypted information may be configured based on encryption of a common information field and one or more user information fields (e.g., a user information list field) within the control frame.

[0314] Thereafter, the second STA can perform decryption of encrypted information and integrity check of control frames based on the key information (S2030).

[0315] In this regard, specific details regarding protection for control frames, key information, specific encryption protocols, encrypted information, frame / MPDU formats, etc. are identical / similar to those described in Fig. 19, and therefore, a detailed description thereof is omitted.

[0316] The method described in the example of FIG. 20 can be performed by the second device (200) of FIG. 1. That is, the second STA of FIG. 20 can be implemented as the second device (200). For example, one or more processors (202) of the second device (200) of FIG. 1 can be configured to verify key information related to protection for a control frame, configure a control frame including encrypted information based on the key information and a specific encryption protocol, and transmit the configured control frame to the first STA.

[0317] In this regard, one or more processors (202) may be configured to perform an operation of applying CCMP or GCMP to a trigger frame to configure a CCMP / GCMP MPDU format based on information shared with a receiving STA before configuring a PPDU (e.g., PTK / GTK for performing encryption / decryption, which encryption / decryption algorithm to use, which field to encrypt / decrypt, etc.).

[0318] Furthermore, one or more memories (204) of the second device (200) may store instructions for performing the method described in the example of FIG. 20 or the examples described below when executed by one or more processors (202).

[0319] The embodiments described above are combinations of components and features of the present disclosure in a predetermined form. Each component or feature should be considered optional unless explicitly stated otherwise. Each component or feature may be implemented without being combined with other components or features. Furthermore, it is also possible to form 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 components or features of one embodiment may be included in another embodiment or may be replaced with corresponding components or features of another embodiment. It is self-evident that claims that do not have an explicit citation relationship in the patent claims may be combined to form embodiments or incorporated as new claims through post-application amendments.

[0320] It will be apparent to those skilled in the art that the present disclosure may be embodied in other specific forms without departing from the essential characteristics thereof. Therefore, the above detailed description should not be construed as limiting in any respect, but rather as illustrative. The scope of the present disclosure should be determined by a reasonable interpretation of the appended claims, and all modifications within the scope of equivalents of the present disclosure are intended to be included within the scope of the present disclosure.

[0321] The scope of the present disclosure includes software or machine-executable instructions (e.g., an operating system, an application, firmware, a program, etc.) that cause operations according to the methods of various embodiments to be executed on a device or a computer, and a non-transitory computer-readable medium having such software or instructions stored thereon and executable on the device or computer. Instructions that can be used to program a processing system to perform the features described in the present disclosure can be stored on / in a storage medium or a computer-readable storage medium, and a computer program product including such a storage medium can be used to implement the features described in the present disclosure. 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 optionally includes one or more storage devices remotely located from the processor(s). The memory or, alternatively, the non-volatile memory device(s) within the memory comprise a non-transitory computer-readable storage medium. The features described in this disclosure may be incorporated into software and / or firmware stored on any of the machine-readable media, which may control the hardware of the processing system and allow the processing system to interact with other mechanisms that utilize results according to embodiments of the present disclosure. Such software or firmware may include, but is not limited to, application code, device drivers, operating systems, and execution environments / containers.

[0322] The method proposed in this disclosure is described with a focus on examples applied to IEEE 802.11-based systems, but can be applied to various wireless LANs or wireless communication systems in addition to IEEE 802.11-based systems.

Claims

1. A method performed by a first station (STA) in a wireless local area network (WLAN) system, the method comprising: A step of verifying key information related to protection for a control frame; A step of receiving a control frame including encrypted information based on a specific encryption protocol from a second STA; and Based on the above key information, a step of performing decryption on the encrypted information and an integrity check on the control frame is included. A method wherein the encrypted information is configured based on encryption of a common information field and one or more user information fields within the control frame.

2. In paragraph 1, The above specific encryption protocol corresponds to CCMP (counter mode with cipher-block chaining message authentication code protocol) or GCMP (galois / counter mode protocol), CCMP-128 or CCMP-256 is used as the cipher suite for the above CCMP. A method wherein GCMP-128 or GCMP-256 is used as a cipher suite for the above GCMP.

3. In paragraph 1, A method wherein the above control frame includes MIC (message integrity code) information calculated based on the above key information.

4. In paragraph 3, A method in which the encrypted information is configured by additionally applying encryption to the MIC information based on the fact that the specific encryption protocol corresponds to CCMP.

5. In paragraph 1, A method wherein the control frame comprises a CCMP header or a GCMP header including a first field for a key ID (identifier) ​​and a second field for a packet number.

6. In paragraph 5, A method wherein the CCMP header or the GCMP header further includes information indicating an MPDU (MAC protocol data unit) format according to the type of the specific encryption protocol within the control frame.

7. In paragraph 1, A method in which information indicating whether protection for the control frame is supported is transmitted and received between the first STA and the second STA.

8. In paragraph 7, A method in which information indicating whether protection for the above control frame is supported is transmitted and received through at least one of a beacon frame, a probe request frame, a probe response frame, a combination request frame, a combination response frame, or the above control frame.

9. In paragraph 1, A method in which a protected frame subfield within a frame control field included in the control frame is set to a predefined specific value based on the application of the specific encryption protocol to the control frame.

10. In paragraph 1, A method in which information indicating an MPDU format according to the type of the specific encryption protocol is transmitted and received between the first STA and the second STA 11. In paragraph 1, Based on the fact that the above control frame corresponds to an individually addressed control frame, the key information is based on a pairwise transient key (PTK) for the first STA and the second STA, A method wherein the key information is based on a GTK (group temporal key) for the first STA and the second STA, based on the control frame corresponding to a group addressed control frame.

12. In paragraph 1, The above control frame corresponds to a trigger frame for triggering data with the second STA, A method wherein the above key information is configured independently from the key information for protecting the above data.

13. In paragraph 1, The above second STA is an access point (AP), A method wherein the first STA is a non-AP STA coupled to the AP.

14. In a first station (STA) device in a wireless local area network (WLAN) system, the device: one or more transmitters and receivers; and comprising one or more processors connected to said one or more transceivers, One or more of the above processors: Verify key information related to protection for control frames; Receive a control frame including encrypted information based on a specific encryption protocol from a second STA; Based on the above key information, decryption of the encrypted information and integrity check of the control frame are set to be performed. A device wherein the encrypted information is configured based on encryption of a common information field and one or more user information fields within the control frame.

15. A method performed by a second station (STA) in a wireless local area network (WLAN) system, the method comprising: A step of verifying key information related to protection for a control frame; A step of constructing a control frame including encrypted information based on the above key information and a specific encryption protocol; and A step of transmitting the above control frame to a first STA, and a step of receiving the control frame from a second STA, A method wherein the encrypted information is configured based on encryption of a common information field and one or more user information fields within the control frame.

16. In a second station (STA) device in a wireless local area network (WLAN) system, the device: one or more transmitters and receivers; and comprising one or more processors connected to said one or more transceivers, One or more of the above processors: Verify key information related to protection for control frames; Constructing a control frame including encrypted information based on the above key information and a specific encryption protocol; A step of transmitting the above control frame to a first STA, but setting it to be received from a second STA; A device wherein the encrypted information is configured based on encryption of a common information field and one or more user information fields within the control frame.

17. In a processing device configured to control a station (STA) in a wireless local area network (WLAN) system, the processing device: one or more processors; and A processing device comprising one or more computer memories operatively connected to said one or more processors and storing instructions for performing a method according to any one of claims 1 to 13 based on execution by said one or more processors.

18. One or more non-transitory computer-readable media storing one or more instructions, A computer-readable medium, wherein the one or more commands are executed by one or more processors to control a device in a wireless LAN system to perform a method according to any one of claims 1 to 13.

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