Physical data unit in wireless LAN system

Abstract

The technical features of the present disclosure may relate to a method performed in a wireless local area network (WLAN) system. The method of the present disclosure may be performed by a transmission opportunity (TXOP) holder that has obtained a TXOP. The TXOP holder may transmit control information about a small physical protocol data unit (PPDU). The TXOP holder may sequentially transmit a first PPDU and a second PPDU within the TXOP. At least one of the first and second PPDUs may not include an L-preamble part. At least one of the first and second PPDUs may include a technical feature for having a short PPDU duration. Low latency traffic may be transmitted between the first and second PPDUs.

Description

Physical data unit in wireless LAN system

[0001] This specification relates to a wireless LAN system, and more particularly, to a method and device for improving a data unit used in a physical layer of a wireless LAN system.

[0002] Wireless local area networks (WLANs) have been improved in various ways. For example, the Extreme High Throughput (EHT) standard can utilize newly proposed increased bandwidth, an improved PHY layer protocol data unit (PPDU) structure, improved sequences, and Hybrid Automatic Repeat Request (HARQ) techniques. The EHT standard can also be referred to as the IEEE 802.11be standard.

[0003] The EHT specification supports high throughput and high data rates, which may include wide bandwidth (e.g., 160 / 320 MHz), 16 streams, and / or multi-link (or multi-band) operation.

[0004] In the EHT specification, wide bandwidth (e.g., 160 / 240 / 320 MHz) can be used to achieve high throughput. Preamble puncturing and multiple RU transmissions can also be used to efficiently utilize bandwidth.

[0005] WLAN systems can be further improved through the Ultra High Reliability (UHR) standard. UHR systems can be referred to as the IEEE 802.11bn standard. UHR systems aim to support ultra-high reliability when transmitting signals to STAs. To achieve this, various technologies are being considered for UHR systems, including high throughput, low latency, and extended range support.

[0006] WLAN systems can define various formats / types or physical versions of Physical Protocol Data Units (PPDUs). The performance of a communication system can be determined by the various characteristics of the PPDUs used in the WLAN system.

[0007] This specification relates to PPDUs in wireless LAN systems. This specification addresses technical issues that arise when a single PPDU becomes excessively long in a wireless LAN system. For example, if a PPDU becomes too long, transmission or reception of other PPDUs becomes impossible until the transmission or reception of the corresponding PPDU is complete. For example, when a STA (Station) must transmit low-latency traffic, various technical issues may arise if the duration of an existing PPDU becomes excessively long.

[0008] This specification addresses the problem of a single PPDU occupying an excessively long time interval. This specification proposes technical features that improve the PPDU structure and enable efficient transmission of low-latency traffic. Using the PPDU proposed in this specification, low-latency traffic that suddenly occurs can be transmitted without excessive delay.

[0009] This specification proposes various technical features. The various technical features of this specification may be related to specific STAs (stations), processors, instructions, etc.

[0010] For example, the technical features of the present specification may relate to a method performed in a specific STA. For example, an example of the present specification may relate to a method performed in a Wireless Local Area Network (WLAN) system. The above-described method may be performed by a TXOP holder that has acquired a transmission opportunity (TXOP). The TXOP holder may transmit control information regarding a small Physical Protocol Data Unit (PPDU). The TXOP holder may transmit a first PPDU within the TXOP. The first PPDU may be configured based on the small PPDU. The first PPDU may include an L-STF (Legacy Short Training Field), an L-LTF (Legacy Long Training Field), an L-SIG (Legacy Signal) field, an RL-SIG (Repeated L-SIG) field, a U-SIG (Universal Signal) field, an STF (Short Training Field), an LTF (Long Training Field), and a data field.

[0011] For example, the TXOP holder may transmit a second PPDU within the TXOP after transmitting the first PPDU. The second PPDU may not include the L-STF, the L-LTF, the L-SIG field, and the RL-SIG field. The second PPDU may be configured based on the small PPDU.

[0012] The technical features described in this specification can produce various advantageous effects. The technical features of this specification can solve technical problems that occur when the length of a single PPDU becomes excessively long in a wireless LAN system. For example, when the PPDU of this specification is used, traffic with low latency can be transmitted efficiently. Since the PPDU of this specification has a shorter duration than a conventional PPDU, traffic with low latency can be transmitted quickly without excessive delay. Since the PPDU of this specification has a shorter duration than a conventional PPDU without degrading performance such as channel estimation or AGC, communication efficiency in a wireless LAN can be improved.

[0013] Figure 1 illustrates an example of a transmitting device and / or a receiving device of the present specification.

[0014] Figure 2 is a conceptual diagram showing the structure of a wireless local area network (WLAN).

[0015] Figure 3 is a diagram illustrating a general link setup process.

[0016] Figure 4 illustrates one embodiment of a multi-link (ML).

[0017] Figure 5 illustrates a PPDU transmitted / received by an STA of this specification.

[0018] Figure 6 is a diagram showing the layout of resource units (RUs) used for 20MHz PPDU.

[0019] Figure 7 is a diagram showing the layout of resource units (RUs) used for 40MHz PPDU.

[0020] Figure 8 is a diagram showing the layout of resource units (RUs) used for 80MHz PPDU.

[0021] Figure 9 shows the operation according to UL-MU.

[0022] Figure 10 shows an example of channels used / supported / defined within the 2.4 GHz band.

[0023] Figure 11 illustrates an example of channels used / supported / defined within the 5 GHz band.

[0024] Figure 12 illustrates an example of channels used / supported / defined within the 6 GHz band.

[0025] Figure 13 shows an example of a header of a MAC frame.

[0026] FIG. 14 illustrates a modified example of a transmitting device and / or a receiving device of the present specification.

[0027] An example of FIG. 15 relates to an example of a PPDU proposed in this specification.

[0028] Figure 16 shows an example of a typical PPDU.

[0029] Figure 17 shows a specific example of a preamble included in a PPDU.

[0030] Figure 18 is an example of a procedure flowchart of this specification.

[0031] Figure 19 is an example of a procedure flowchart of this specification.

[0032] In this specification, “A or B” can mean “only A,” “only B,” or “both A and B.” In other words, “A or B” in this specification can be interpreted as “A and / or B.” For example, “A, B or C” in this specification can mean “only A,” “only B,” “only C,” or “any combination of A, B, and C.”

[0033] As used herein, a slash ( / ) or comma can mean "and / or." For example, "A / B" can mean "A and / or B." Accordingly, "A / B" can mean "only A," "only B," or "both A and B." For example, "A, B, C" can mean "A, B, or C."

[0034] In this specification, “at least one of A and B” may mean “only A,” “only B,” or “both A and B.” Additionally, in this specification, the expressions “at least one of A or B” or “at least one of A and / or B” may be interpreted identically to “at least one of A and B.”

[0035] In addition, parentheses used in this specification may mean “for example”. Specifically, when it is indicated as “control information (UHR-Signal field)”, the “UHR-Signal field” may be proposed as an example of “control information”. In other words, the “control information” in this specification is not limited to the “UHR-Signal field”, and the “UHR-Signal field” may be proposed as an example of “control information”. In addition, even when it is indicated as “control information (UHR-Signal field)”, the “UHR-Signal field” may be proposed as an example of “control information”.

[0036] Additionally, as used herein, “a / an” can mean “at least one” or “one or more.” Additionally, terms ending in “(s)” can mean “at least one” or “one or more.”

[0037] Additionally, the expressions “based on” or “on the basis of” or “according to” used herein mean “based at least in part on” and not “based solely on.”

[0038] Technical features individually described in a single drawing in this specification may be implemented individually or simultaneously.

[0039] The following examples of this specification can be applied to various wireless communication systems. For example, the following examples of this specification can be applied to wireless local area network (WLAN) systems. For example, the present specification can be applied to the IEEE 802.11a / g / n / ac / ax / be / bn standards. In addition, the examples of this specification can be applied to the Ultra High Reliability (UHR) standard or the next-generation wireless LAN standard that enhances IEEE 802.11bn. In addition, the examples of this specification can be applied to mobile communication systems. For example, the examples of this specification can be applied to mobile communication systems based on Long Term Evolution (LTE) and its evolution based on the 3rd Generation Partnership Project (3GPP) standard.

[0040] In order to explain the technical features of this specification, the technical features to which this specification can be applied are described below.

[0041] Figure 1 illustrates an example of a transmitting device and / or a receiving device of the present specification.

[0042] An example of FIG. 1 can perform various technical features described below. FIG. 1 relates to at least one STA (station). For example, the STA (110, 120) of the present specification may also be referred to by various names such as a mobile terminal, a wireless device, a Wireless Transmit / Receive Unit (WTRU), a User Equipment (UE), a Mobile Station (MS), a Mobile Subscriber Unit, or simply a user. The STA (110, 120) of the present specification may also be referred to by various names such as a network, a base station, a Node-B, an access point (AP), a repeater, a router, a relay, etc. The STA (110, 120) of the present specification may also be referred to by various names such as a receiving apparatus, a transmitting apparatus, a receiving STA, a transmitting STA, a receiving device, a transmitting device, etc.

[0043] For example, STA (110, 120) may perform the role of an AP (access point) or a non-AP role. That is, STA (110, 120) of the present specification may perform the functions of an AP and / or a non-AP. In the present specification, AP may also be indicated as an AP STA.

[0044] The STA (110, 120) of this specification can support various communication standards other than the IEEE 802.11 standard. For example, it can support communication standards according to the 3GPP standard (e.g., LTE, LTE-A, 5G NR standard). In addition, the STA of this specification can be implemented in various devices such as mobile phones, vehicles, and personal computers. In addition, the STA of this specification can support communication for various communication services such as voice calls, video calls, data communications, and autonomous driving (Self-Driving, Autonomous-Driving).

[0045] In this specification, STA (110, 120) may include a medium access control (MAC) and a physical layer interface for a wireless medium that follow the provisions of the IEEE 802.11 standard.

[0046] Based on the sub-drawing (a) of Fig. 1, STA (110, 120) is described as follows.

[0047] The first STA (110) may include a processor (111), a memory (112), and a transceiver (113). The illustrated processor, memory, and transceiver may each be implemented as separate chips, or at least two blocks / functions may be implemented through a single chip.

[0048] The transceiver (113) of the first STA performs signal transmission and reception operations. Specifically, it can transmit and receive IEEE 802.11 packets (e.g., IEEE 802.11a / b / g / n / ac / ax / be, etc.).

[0049] For example, the first STA (110) can perform the intended operation of the AP. For example, the processor (111) of the AP can receive a signal through the transceiver (113), process the received signal, generate a transmission signal, and perform control for signal transmission. The memory (112) of the AP can store a signal received through the transceiver (113) (i.e., a reception signal) and store a signal to be transmitted through the transceiver (i.e., a transmission signal).

[0050] For example, the second STA (120) can perform the intended operation of a non-AP STA. For example, the transceiver (123) of the non-AP performs signal transmission and reception operations. Specifically, it can transmit and receive IEEE 802.11 packets (e.g., IEEE 802.11a / b / g / n / ac / ax / be, etc.).

[0051] For example, the processor (121) of the Non-AP STA can receive a signal through the transceiver (123), process the received signal, generate a transmission signal, and perform control for signal transmission. The memory (122) of the Non-AP STA can store a signal received through the transceiver (123) (i.e., a reception signal) and store a signal to be transmitted through the transceiver (i.e., a transmission signal).

[0052] For example, in the specification below, the operation of a device indicated as AP may be performed in the first STA (110) or the second STA (120). For example, if the first STA (110) is an AP, the operation of the device indicated as AP may be controlled by the processor (111) of the first STA (110), and a related signal may be transmitted or received through a transceiver (113) controlled by the processor (111) of the first STA (110). In addition, control information related to the operation of the AP or a transmission / reception signal of the AP may be stored in the memory (112) of the first STA (110). In addition, when the second STA (110) is an AP, the operation of the device indicated as an AP is controlled by the processor (121) of the second STA (120), and a related signal can be transmitted or received through a transceiver (123) controlled by the processor (121) of the second STA (120). In addition, control information related to the operation of the AP or the transmission / reception signal of the AP can be stored in the memory (122) of the second STA (110).

[0053] For example, in the specification below, the operation of a device indicated as a non-AP (or User-STA) may be performed in the STA (110) or the second STA (120). For example, if the second STA (120) is a non-AP, the operation of the device indicated as a non-AP may be controlled by the processor (121) of the second STA (120), and a related signal may be transmitted or received through a transceiver (123) controlled by the processor (121) of the second STA (120). In addition, control information related to the operation of the non-AP or the transmission / reception signal of the AP may be stored in the memory (122) of the second STA (120). For example, if the first STA (110) is a non-AP, the operation of a device indicated as a non-AP is controlled by the processor (111) of the first STA (110), and a related signal may be transmitted or received through a transceiver (113) controlled by the processor (111) of the first STA (120). In addition, control information related to the operation of the non-AP or the transmission / reception signal of the AP may be stored in the memory (112) of the first STA (110).

[0054] In the following specification, devices called (transmitting / receiving) STA, first STA, second STA, STA1, STA2, AP, first AP, second AP, AP1, AP2, (transmitting / receiving) Terminal, (transmitting / receiving) device, (transmitting / receiving) apparatus, network, etc. may refer to the STA (110, 120) of FIG. 1. For example, devices indicated as (transmitting / receiving) STA, first STA, second STA, STA1, STA2, AP, first AP, second AP, AP1, AP2, (transmitting / receiving) Terminal, (transmitting / receiving) device, (transmitting / receiving) apparatus, network, etc. without specific drawing symbols may also refer to the STA (110, 120) of FIG. 1. For example, in the example below, the operation of various STAs transmitting and receiving signals (e.g., PPPDU) may be performed by the transceiver (113, 123) of FIG. 1. In addition, in the example below, the operation of various STAs generating transmission and reception signals or performing data processing or calculations in advance for transmission and reception signals may be performed by the processor (111, 121) of FIG. 1.For example, an example of an operation that generates a transmission / reception signal or performs data processing or operation in advance for a transmission / reception signal may include 1) an operation of determining / obtaining / configuring / computing / decoding / encoding bit information of a subfield (SIG, STF, LTF, Data) field included in a PPDU, 2) an operation of determining / configuring / obtaining time resources or frequency resources (e.g., subcarrier resources) used for a subfield (SIG, STF, LTF, Data) field included in a PPDU, 3) an operation of determining / configuring / obtaining a specific sequence (e.g., a pilot sequence, an STF / LTF sequence, an extra sequence applied to SIG) used for a subfield (SIG, STF, LTF, Data) field 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 (112, 122) of FIG. 1.

[0055] The device / STA of the sub-drawing (a) of the above-described FIG. 1 can be modified as in the sub-drawing (b) of FIG. 1. Hereinafter, the STA (110, 120) of the present specification will be described based on the sub-drawing (b) of FIG. 1.

[0056] For example, the transceiver (113, 123) illustrated in sub-drawing (b) of FIG. 1 may perform the same function as the transceiver illustrated in sub-drawing (a) of FIG. 1 described above. For example, the processing chip (114, 124) illustrated in sub-drawing (b) of FIG. 1 may include a processor (111, 121) and a memory (112, 122). The processor (111, 121) and the memory (112, 122) illustrated in sub-drawing (b) of FIG. 1 may perform the same function as the processor (111, 121) and the memory (112, 122) illustrated in sub-drawing (a) of FIG. 1 described above.

[0057] The mobile terminal, wireless device, Wireless Transmit / Receive Unit (WTRU), User Equipment (UE), Mobile Station (MS), Mobile Subscriber Unit, user, user STA, network, Base Station, Node-B, Access Point (AP), repeater, router, relay, receiving device, transmitting device, receiving STA, transmitting STA, receiving Device, transmitting Device, receiving Apparatus, and / or transmitting Apparatus described below may refer to the STA (110, 120) illustrated in the sub-drawings (a) / (b) of FIG. 1, or may refer to the processing chip (114, 124) illustrated in the sub-drawing (b) of FIG. 1. That is, the technical feature of the present specification may be performed in the STA (110, 120) illustrated in the sub-drawings (a) / (b) of FIG. 1, or may be performed only in the processing chip (114, 124) illustrated in the sub-drawings (b) of FIG. 1. For example, the technical feature that the transmitting STA transmits a control signal may be understood as a technical feature that the control signal generated in the processor (111, 121) illustrated in the sub-drawings (a) / (b) of FIG. 1 is transmitted through the transceiver (113, 123) illustrated in the sub-drawings (a) / (b) of FIG. 1. Alternatively, the technical feature that the transmitting STA transmits a control signal may be understood as a technical feature that the control signal to be transmitted to the transceiver (113, 123) is generated in the processing chip (114, 124) illustrated in the sub-drawings (b) of FIG. 1.

[0058] For example, the technical feature of a receiving STA receiving a control signal can be understood as a technical feature of a control signal being received by a transceiver (113, 123) illustrated in sub-drawing (a) of FIG. 1. Alternatively, the technical feature of a receiving STA receiving a control signal can be understood as a technical feature of a control signal received by a transceiver (113, 123) illustrated in sub-drawing (a) of FIG. 1 being acquired by a processor (111, 121) illustrated in sub-drawing (a) of FIG. 1. Alternatively, the technical feature of a receiving STA receiving a control signal can be understood as a technical feature of a control signal received by a transceiver (113, 123) illustrated in sub-drawing (b) of FIG. 1 being acquired by a processing chip (114, 124) illustrated in sub-drawing (b) of FIG.

[0059] Referring to the sub-drawing (b) of FIG. 1, software code (115, 125) may be included in the memory (112, 122). The software code (115, 125) may include instructions that control the operation of the processor (111, 121). The software code (115, 125) may be included in various programming languages.

[0060] The processor (111, 121) or processing chip (114, 124) illustrated in FIG. 1 may include an application-specific integrated circuit (ASIC), another chipset, a logic circuit, and / or a data processing device. The processor may be an application processor (AP). For example, the processor (111, 121) or processing chip (114, 124) illustrated in FIG. 1 may include at least one of a digital signal processor (DSP), a central processing unit (CPU), a graphics processing unit (GPU), and a modem (modulator and demodulator). For example, the processor (111, 121) or processing chip (114, 124) illustrated in FIG. 1 may be a SNAPDRAGON® series processor manufactured by Qualcomm®, an EXYNOS® series processor manufactured by Samsung®, an A series processor manufactured by Apple®, a HELIO® series processor manufactured by MediaTek®, an ATOM® series processor manufactured by INTEL®, or an enhanced processor thereof.

[0061] In this specification, uplink may mean a link for communication from a non-AP STA to an AP STA, and uplink PPDU / packet / signal, etc. may be transmitted through the uplink. In addition, in this specification, downlink may mean a link for communication from an AP STA to a non-AP STA, and downlink PPDU / packet / signal, etc. may be transmitted through the downlink.

[0062] Figure 2 is a conceptual diagram showing the structure of a wireless local area network (WLAN).

[0063] The upper part of Figure 2 shows the structure of the infrastructure BSS (basic service set) of IEEE (institute of electrical and electronic engineers) 802.11.

[0064] Referring to the top of FIG. 2, the wireless LAN system may include one or more infrastructure BSSs (200, 205) (hereinafter, BSS). The BSSs (200, 205) are a collection of APs and STAs, such as an access point (AP) 225 and a station (STA1, 200-1), that have successfully synchronized and can communicate with each other, and are not a concept that designates a specific area. The BSS (205) may also include one or more STAs (205-1, 205-2) that can be associated with one AP (230).

[0065] A BSS may include at least one STA, an AP (225, 230) providing a distribution service, and a distribution system (DS, 210) connecting multiple APs.

[0066] A distributed system (210) can connect multiple BSSs (200, 205) to implement an extended service set (ESS) 240. An ESS (240) can be used as a term to indicate a network formed by connecting one or more APs through the distributed system (210). APs included in a single ESS (240) can have the same SSID (service set identification).

[0067] The portal (portal, 220) can act as a bridge to connect a wireless LAN network (IEEE 802.11) to another network (e.g., 802.X).

[0068] In a BSS such as the upper part of Fig. 2, a network between APs (225, 230) and a network between APs (225, 230) and STAs (200-1, 205-1, 205-2) can be implemented. However, it may also be possible to establish a network and perform communication between STAs without an AP (225, 230). A network that establishes a network and performs communication between STAs without an AP (225, 230) is defined as an ad-hoc network or an independent basic service set (IBSS).

[0069] The bottom of Figure 2 is a conceptual diagram showing IBSS.

[0070] Referring to the bottom of Fig. 2, the IBSS is a BSS that operates in ad-hoc mode. Since the IBSS does not include an AP, there is no centralized management entity. That is, in the IBSS, the STAs (250-1, 250-2, 250-3, 255-4, 255-5) are managed in a distributed manner. In the IBSS, all STAs (250-1, 250-2, 250-3, 255-4, 255-5) can be mobile STAs, and access to the distributed system is not permitted, forming a self-contained network.

[0071] Figure 3 is a diagram illustrating a general link setup process.

[0072] In step S310, the STA may perform a network discovery operation. This network discovery operation may include scanning by the STA. That is, for the STA to access the network, it must find a network it can join. Before joining a wireless network, the STA must identify compatible networks. The process of identifying networks in a specific area is called scanning. Scanning methods include active scanning and passive scanning.

[0073] Figure 3 illustrates a network discovery operation that includes an active scanning process as an example. In active scanning, an STA performing scanning transmits a probe request frame to discover which APs exist in the vicinity while moving between channels and waits for a response. A responder transmits a probe response frame to the STA that transmitted the probe request frame in response to 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 a BSS, the AP transmits the beacon frame, so the AP becomes the responder. In an IBSS, the STAs within the IBSS take turns transmitting beacon frames, so the responder is not constant. 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.

[0074] Although not shown in the example of FIG. 3, the scanning operation can also be performed in a passive scanning manner. An STA performing scanning based on passive scanning can wait for a beacon frame while moving between channels. A beacon frame is one of the management frames in IEEE 802.11. It announces the presence of a wireless network and is periodically transmitted so that the scanning STA can find the wireless network and participate in the wireless network. In the BSS, the AP periodically transmits the beacon frame, and in the IBSS, the STAs within the IBSS take turns transmitting the beacon frame. When the scanning STA 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. An STA that receives a beacon frame can store the BSS-related information included in the received beacon frame, move to the next channel, and perform scanning on the next channel in the same manner.

[0075] An STA that discovers a network can perform an authentication process through 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. The authentication process of S320 may include a process in which the STA transmits an authentication request frame to the AP, and the AP responds by transmitting an authentication response frame to the STA. The authentication frame used for the authentication request / response corresponds to a management frame.

[0076] 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.

[0077] An STA can transmit 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.

[0078] A successfully authenticated STA may perform an association process based on step S330. The association process includes a process in which the STA transmits an association request frame to the AP, and the AP transmits an association response frame to the STA in response. For example, the association request frame may include information related to various capabilities, such as a beacon listen interval, a service set identifier (SSID), supported rates, supported channels, RSN, mobility domain, supported operating classes, a Traffic Indication Map Broadcast request, and interworking service capabilities. For example, the association response frame may contain information related to various capabilities, status codes, Association ID (AID), supported rates, Enhanced Distributed Channel Access (EDCA) parameter sets, Received Channel Power Indicator (RCPI), Received Signal to Noise Indicator (RSNI), mobility domains, timeout interval (association comeback time), overlapping BSS scan parameters, TIM broadcast response, QoS maps, etc.

[0079] In step S340, the STA may perform a security setup process. The security setup process of step S340 may include, for example, a process of setting up a private key through a four-way handshaking using an Extensible Authentication Protocol over LAN (EAPOL) frame.

[0080] Figure 4 illustrates one embodiment of a multi-link (ML).

[0081] As illustrated in FIG. 4, multiple multi-link devices (MLDs) can communicate over a remote link. The MLDs can be categorized into AP MLDs including multiple AP STAs and non-AP MLDs including multiple non-AP STAs. That is, the AP MLD can include affiliated APs (i.e., AP STAs), and the non-AP MLD can include affiliated STAs (i.e., non-AP STAs, or user-STAs).

[0082] A multilink may include a first link and a second link, and different channels / subchannels / frequency resources may be allocated to the first and second links. The first and second multilinks may be identified through a link ID of 4 bits (or other n bits). The first and second links may be configured in the same 2.4 GHz, 5 GHz, or 6 GHz band. Alternatively, the first link and the second link may be configured in different bands.

[0083] The AP MLD of FIG. 4 includes three affiliated APs. In the example of FIG. 4, AP1 may operate in the 2.4 GHz band, AP2 may operate in the 5 GHz band, and AP3 may operate in the 6 GHz band. In the example of FIG. 4, the first link in which AP1 and non-AP1 operate may be defined as a channel / subchannel / frequency resource within the 2.4 GHz band. Furthermore, in the example of FIG. 4, the second link in which AP2 and non-AP2 operate may be defined as a channel / subchannel / frequency resource within the 5 GHz band. Furthermore, in the example of FIG. 4, the third link in which AP3 and non-AP3 operate may be defined as a channel / subchannel / frequency resource within the 6 GHz band.

[0084] In the example of FIG. 4, AP1 may initiate a multi-link setup procedure (ML setup procedure) by transmitting an Association Request frame to non-AP STA1. In the example of FIG. 4, non-AP STA1 may transmit an Association Response frame in response to the Association Request frame. Each AP (e.g., AP1 / 2 / 3) illustrated in FIG. 4 may be identical to the AP illustrated in FIG. 1 and / or FIG. 2, and each non-AP (e.g., non-AP1 / 2 / 3) illustrated in FIG. 4 may be identical to the STA (i.e., user-STA or non-AP STA) illustrated in FIG. 1 and / or FIG. 2.

[0085] The specific features of this specification are not limited to the specific features of FIG. 4. That is, the number of links can be defined in various ways, and multiple links can be defined in various ways within at least one band.

[0086] FIG. 5 illustrates a PPDU (physical protocol data unit or physical layer (PHY) protocol data unit) transmitted / received by an STA of this specification.

[0087] The STA (e.g., AP STA, non-AP STA, AP MLD, non-AP MLD) of the present specification can transmit and / or receive the PPDU of FIG. 5. The PPDU described in the present specification may have, for example, the structure of FIG. 5. In addition, the PPDU described in the present specification may be called by various names such as a transmission PPDU, a reception PPDU, a first type PPDU, or an Nth type PPDU, etc. The PPDU described in the present specification can be used in a WLAN system defined according to IEEE 802.11bn and / or a next-generation WLAN system that improves IEEE 802.11bn.

[0088] The PPDU of FIG. 5 may be related to various PPDU types used in a UHR system. For example, the example of FIG. 5 may be used for at least one of a single-user (SU) mode / type / transmission, a multi-user (MU) mode / type / transmission, and a null data packet (NDP) mode / type / transmission related to channel sounding. For example, if the example of FIG. 5 is related to NDP, the Data field illustrated may be omitted. If the PPDU of FIG. 5 is used for a trigger-based (TB) mode, the UHR-SIG of FIG. 5 may be omitted. In other words, an STA that has received a trigger frame for UL-MU (Uplink-MU) communication may transmit a PPDU with the UHR-SIG omitted in the example of FIG. 5.

[0089] In FIG. 5, L-STF or UHR-LTF may be called a preamble or physical preamble, and may be generated / transmitted / received / acquired / decoded in the physical layer (included in the transmitting / receiving STA).

[0090] Each block illustrated in Fig. 5 may be called a field / subfield / signal, etc. The names of these fields / subfields / signals may be, as illustrated in Fig. 5, L-STF (legacy short training field), L-LTF (legacy long training field), L-SIG (legacy signal), RL-SIG (repeated L-SIG), U-SIG (Universal Signal), UHR-SIG (UHR-signal), etc.

[0091] The subcarrier spacing of the L-STF, L-LTF, L-SIG, RL-SIG, U-SIG, and UHR-SIG fields in FIG. 5 may be set to 312.5 kHz, and the subcarrier spacing of the UHR-STF, UHR-LTF, and Data fields may be set to 78.125 kHz. That is, the tone index (or subcarrier index) of the L-STF, L-LTF, L-SIG, RL-SIG, U-SIG, and UHR-SIG fields may be expressed in units of 312.5 kHz, and the tone index (or subcarrier index) of the UHR-STF, UHR-LTF, and Data fields may be expressed in units of 78.125 kHz.

[0092] In the PPDU of Fig. 5, L-LTF and L-STF may be identical to conventional fields (e.g., non-HT LTF and non-HT STF defined in conventional WLAN standards).

[0093] The L-SIG field of FIG. 5 may include, for example, 24 bits of bit information. For example, the 24 bits of information may include a 4 bit Rate field, a 1 bit Reserved bit, a 12 bit Length field, a 1 bit Parity bit, and a 6 bit Tail bit. 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, if the PPDU is a non-HT (non-High Throughput), HT (High Throughput), VHT (Very High Throughput) PPDU, or an EHT (extremely high throughput) PPDU or UHR PPDU, the value of the Length field may be determined as a multiple of 3. For example, if the PPDU is a HE PPDU, the value of the Length field may be determined as "a multiple of 3 + 1" or "a multiple of 3 + 2". In other words, for non-HT, HT, VHT PPDU, EHT PPDU, UHR PPDU, the value of the Length field can be determined as a multiple of 3, and for HE (High Efficiency) PPDU, the value of the Length field can be determined as "a multiple of 3 + 1" or "a multiple of 3 + 2". In other words, the Length field in an UHR PPDU is set to a value satisfying the condition that the remainder is zero when LENGTH is divided by 3.

[0094] For example, (non-AP and AP) STAs can apply BCC encoding based on a code rate of 1 / 2 to the 24 bits of information in the L-SIG field. Then, the transmitting STA can obtain 48 BCC coded bits. BPSK modulation can be applied to the 48 coded bits to generate 48 BPSK symbols. The transmitting STA can map the 48 BPSK symbols to positions excluding the pilot subcarriers {subcarrier index -21, -7, +7, +21} and the DC subcarrier {subcarrier index 0}. As a result, the 48 BPSK symbols can be mapped to subcarrier indices -26 to -22, -20 to -8, -6 to -1, +1 to +6, +8 to +20, and +22 to +26. The transmitting STA can additionally map the signal {-1, -1, -1, 1} to the subcarrier indices {-28, -27, +27, +28}. The above signal can be used for channel estimation for the frequency domain corresponding to {-28, -27, +27, +28}.

[0095] For example, (non-AP and AP) STA can generate RL-SIG, which is generated in the same manner as L-SIG. BPSK modulation can be applied to RL-SIG. Receiving (non-AP and AP) STA can determine whether the received PPDU is a HE PPDU, EHT PPDU, or UHR PPDU based on the presence of RL-SIG. In other words, if RL-SIG is present, receiving (non-AP and AP) STA can determine whether the received PPDU is one of HE PPDU, EHT PPDU, or UHR PPDU. In other words, if RL-SIG is not present, receiving (non-AP and AP) STA can determine whether the received PPDU is one of non-HT PPDU, HT PPDU, or VHT PPDU. In other words, the RL-SIG field is a repeat of the L-SIG field and is used to differentiate an UHR PPDU from a non-HT PPDU, HT PPDU, and VHT PPDU.

[0096] After the RL-SIG in Fig. 5, a U-SIG (Universal SIG) may be inserted. The U-SIG may be called by various names such as the first SIG field, the first SIG, the first type SIG, the control signal, the control signal field, the first (type) control signal, the common control field, and the common control signal.

[0097] A U-SIG can contain N bits of information and can include information for identifying the type of EHT PPDU. For example, a U-SIG can be formed based on two symbols (e.g., two consecutive OFDM symbols). Each symbol (e.g., an OFDM symbol) for a U-SIG can have a duration of 4 microseconds. Each symbol of a U-SIG can be used to transmit 26 bits of information. For example, each symbol of a U-SIG can be transmitted and received based on 52 data tones and 4 pilot tones.

[0098] For example, A bit information (e.g., 52 uncoded bits) can be transmitted through U-SIG, and the first symbol of U-SIG can transmit the first X bits of information (e.g., 26 uncoded bits) out of the total A bit information, and the second symbol of U-SIG can transmit the remaining Y bits of information (e.g., 26 uncoded bits) out of the total A bit information. For example, the transmitting STA can obtain 26 uncoded bits included in each U-SIG symbol. The transmitting STA can perform convolutional encoding (i.e., BCC encoding) based on a rate of R=1 / 2 to generate 52 coded bits, and perform interleaving on the 52 coded bits. The transmitting STA can perform BPSK modulation on the interleaved 52 coded bits to generate 52 BPSK symbols allocated to each U-SIG symbol. A single U-SIG symbol can be transmitted based on 56 tones (subcarriers) from subcarrier index -28 to subcarrier index +28, excluding DC index 0. The 52 BPSK symbols generated by the transmitting STA can be transmitted based on the remaining tones (subcarriers) excluding the pilot tones -21, -7, +7, and +21.

[0099] For example, A bit information (e.g., 52 uncoded bits) transmitted by U-SIG may include a CRC field (e.g., a 4-bit long field) and a tail field (e.g., a 6-bit long field). The CRC field and the tail field may be transmitted through the second symbol of the U-SIG. The CRC field may be generated based on 26 bits allocated to the first symbol of the U-SIG and the remaining 16 bits excluding the CRC / tail field within the second symbol, and may be generated based on a conventional CRC calculation algorithm. In addition, the tail field may be used to terminate the trellis of the convolutional decoder and may be set to, for example, "000000".

[0100] The A bit information (e.g., 52 uncoded bits) transmitted by the U-SIG (or U-SIG field) can be divided into version-independent bits and version-dependent bits. For example, the size of the version-independent bits can be fixed or variable. For example, the version-independent bits can be assigned only to the first symbol of the U-SIG, or the version-independent bits can be assigned to both the first symbol and the second symbol of the U-SIG. For example, 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.

[0101] For example, the version-independent bits of the U-SIG may include a 3-bit PHY version identifier. For example, the 3-bit PHY version identifier may include information related to the PHY version of the transmitted and received PPDU. For example, a first value (e.g., a value of 000) of the 3-bit PHY version identifier may indicate that the transmitted and received PPDU is an EHT PPDU. In addition, a second value (e.g., a value of 001) of the 3-bit PHY version identifier may indicate that the transmitted and received PPDU is an UHR PPDU.

[0102] In other words, when the (AP / non-AP) STA transmits an EHT PPDU, it can set the 3-bit PHY version identifier to the first value. In other words, the receiving (AP / non-AP) STA can determine that the received PPDU is an EHT PPDU based on the PHY version identifier having the first value, and can determine that the received PPDU is an UHR PPDU based on the PHY version identifier having the second value.

[0103] For example, the version-independent bits of U-SIG may include a 1-bit UL / DL flag field. The first value of the 1-bit UL / DL flag field relates to UL communication, and the second value of the UL / DL flag field relates to DL communication.

[0104] For example, the version-independent bits of U-SIG may contain information about the length of the TXOP and information about the BSS color ID.

[0105] For example, if a UHR PPDU is classified into various types (e.g., a type related to SU transmission (performed based on UL or DL), a type related to DL transmission, a type related to NDP transmission, a type related to DL non-MU-MIMO, a type related to DL MU-MIMO, a type related to Multi-AP operation, a type related to CBF (Coordinated beamforming), SR (Spatial Reuse), a type related to C-OFDMA (Coordinated OFDMA), a type related to C-TDMA (Coordinated TDMA)), information about the type of the EHT PPDU (e.g., 2-bit or 3-bit information) can be included in the version-dependent bits of the U-SIG.

[0106] For example, U-SIG may include 1) a bandwidth field including information about bandwidth, 2) a field including information about a Modulation and Coding Scheme (MCS) technique applied to UHR-SIG, 3) an indication field including information about whether a dual subcarrier modulation (DCM) technique is applied to UHR-SIG, 4) a field including information about the number of symbols used for UHR-SIG, 5) a field including information about whether UHR-SIG is generated over the entire band, 6) a field including information about the type of UHR-LTF / STF, and 7) a field indicating the length of UHR-LTF and the CP length.

[0107] Preamble puncturing may be applied to the PPDU of FIG. 5. Preamble puncturing refers to applying puncturing to a portion of the entire bandwidth of the PPDU (e.g., the secondary 20 MHz band). For example, when an 80 MHz PPDU is transmitted, the STA applies puncturing to the secondary 20 MHz band within the 80 MHz band, and can transmit the PPDU only through the primary 20 MHz band and the secondary 40 MHz band.

[0108] For example, the pattern of preamble puncturing can be preset. For example, when the first puncturing pattern is applied, puncturing can be applied only to the secondary 20 MHz band within the 80 MHz band. For example, when the second puncturing pattern is applied, puncturing can be applied only to one of the two secondary 20 MHz bands included in the secondary 40 MHz band within the 80 MHz band. For example, when the third puncturing pattern is applied, puncturing can be applied only to the secondary 20 MHz band included in the primary 80 MHz band within the 160 MHz band (or 80+80 MHz band). For example, when the fourth puncturing pattern is applied, a primary 40 MHz band included in the primary 80 MHz band within the 160 MHz band (or 80+80 MHz band) may be present, and puncturing may be applied to at least one 20 MHz channel that does not belong to the primary 40 MHz band.

[0109] Information regarding preamble puncturing applied to the PPDU may be included in the U-SIG and / or UHR-SIG. For example, the first field of the U-SIG may include information regarding the contiguous bandwidth of the PPDU, and the second field of the U-SIG may include information regarding preamble puncturing applied to the PPDU.

[0110] For example, U-SIG and UHR-SIG may include information regarding preamble puncturing based on the following method. If the bandwidth of the PPDU exceeds 80 MHz, the U-SIG may be individually configured in units of 80 MHz. For example, if the bandwidth of the PPDU is 160 MHz, the PPDU may include a first U-SIG for the first 80 MHz band and a second U-SIG for the second 80 MHz band. In this case, the first field of the first U-SIG may include information regarding the 160 MHz bandwidth, and the second field of the first U-SIG may include information regarding preamble puncturing applied to the first 80 MHz band (i.e., information regarding the preamble puncturing pattern). Additionally, the first field of the second U-SIG may include information about a 160 MHz bandwidth, and the second field of the second U-SIG may include information about preamble puncturing applied to the second 80 MHz band (i.e., information about a preamble puncturing pattern). Meanwhile, the UHR-SIG consecutive to the first U-SIG may include information about preamble puncturing applied to the second 80 MHz band (i.e., information about a preamble puncturing pattern), and the UHR-SIG consecutive to the second U-SIG may include information about preamble puncturing applied to the first 80 MHz band (i.e., information about a preamble puncturing pattern).

[0111] Additionally or alternatively, U-SIG and UHR-SIG may include information regarding preamble puncturing based on the following methods. U-SIG may include information regarding preamble puncturing for all bands (i.e., information regarding preamble puncturing patterns). That is, UHR-SIG may not include information regarding preamble puncturing, and only U-SIG may include information regarding preamble puncturing (i.e., information regarding preamble puncturing patterns).

[0112] U-SIGs can be configured in 20 MHz units. For example, if an 80 MHz PPDU is configured, U-SIGs can be duplicated. That is, four identical U-SIGs can be included within an 80 MHz PPDU. PPDUs exceeding the 80 MHz bandwidth can contain different U-SIGs.

[0113] The UHR-SIG of FIG. 5 may include control information for a receiving STA. The UHR-SIG may be transmitted via at least one symbol, and each symbol may have a length of 4 us. Information regarding the number of symbols used for the UHR-SIG may be included in the U-SIG.

[0114] UHR-SIG provides additional signals to the U-SIG field to enable STAs to interpret / decode UHR PPDUs. The UHR-SIG field may contain U-SIG overflow bits that are common to all users. The UHR-SIG field also contains resource allocation information, allowing STAs to look up resources used in fields containing data fields / UHR-STF / UHR-LTF (i.e., UHR modulated fields of an UHR PPDU).

[0115] The frequency resources of the UHR-LTF, UHR-STF, and data fields illustrated in FIG. 5 can be determined based on RUs (resource units) defined by multiple subcarriers / tones. That is, the UHR-LTF, UHR-STF, and data fields of this specification can be transmitted / received through RUs (resource units) defined by multiple subcarriers / tones.

[0116] FIG. 6 is a diagram illustrating the layout of resource units (RUs) used for a 20 MHz PPDU. That is, the UHR-LTF, UHR-STF, and / or data fields included in the 20 MHz PPDU can be transmitted / received through at least one of the various RUs defined in FIG. 6.

[0117] As shown at the top of Fig. 6, 26 units (i.e., units corresponding to 26 tones) can be arranged. Six tones can be used as a guard band in the leftmost band of the 20 MHz band, and five tones can be used as a guard band in the rightmost band of the 20 MHz band. In addition, seven DC tones can be inserted in the center band, i.e., the DC band, and 26 units corresponding to 13 tones can exist on each side of the DC band. In addition, 26 units, 52 units, and 106 units can be allocated to other bands. Each unit can be allocated for a receiving station, i.e., a user.

[0118] Meanwhile, the RU arrangement of FIG. 6 is utilized not only in a situation for multiple users (MUs) but also in a situation for a single user (SU), in which case it is possible to use one 242-unit as shown at the bottom of FIG. 4, in which case three DC tones can be inserted.

[0119] In the example of Fig. 6, RUs of various sizes, such as 26-RU, 52-RU, 106-RU, and 242-RU, are proposed. Since the specific sizes of these RUs can be expanded or increased, the present embodiment is not limited to the specific size of each RU (i.e., the number of corresponding tones). In this specification, N-RU may be represented as N-tone RU, etc. For example, 26-RU may be represented as 26-tone RU.

[0120] Figure 7 is a diagram showing the layout of resource units (RUs) used for 40MHz PPDU.

[0121] As in the example of Fig. 6 where RUs of various sizes were used, the example of Fig. 7 can also use 26-RU, 52-RU, 106-RU, 242-RU, 484-RU, etc. In addition, 5 DC tones can be inserted at the center frequency, 12 tones can be used as a guard band in the leftmost band of the 40 MHz band, and 11 tones can be used as a guard band in the rightmost band of the 40 MHz band.

[0122] Additionally, as illustrated, 484 RUs may be used when used for a single user. Meanwhile, the specific number of RUs may be changed, as in the example of FIG. 6.

[0123] Figure 8 is a diagram illustrating the layout of resource units (RUs) used for an 80MHz PPDU. The layout of resource units (RUs) used in this specification may vary. For example, the layout of resource units (RUs) used in the 80MHz band may vary.

[0124] Figure 9 illustrates an operation according to UL-MU. As illustrated, a transmitting STA (e.g., AP) can acquire a TXOP (925) by performing channel access through contending (i.e., backoff operation) and transmit a trigger frame (930). That is, the transmitting STA (e.g., AP) can transmit a PPDU including a trigger frame (930). When a PPDU including a trigger frame is received, a TB (trigger-based) PPDU is transmitted after a delay of SIFS.

[0125] TB PPDUs (941, 942) are transmitted at the same time and can be transmitted from multiple STAs (e.g., User STAs) whose AIDs are indicated in the Trigger frame (930). The ACK frame (950) for the TB PPDU can be implemented in various forms. For example, the ACK frame (950) for the TB PPDU can be implemented in the form of a BA (block ACK).

[0126] In FIG. 9, transmission(s) of a Trigger Frame (930), TB PPDU (941, 942) and / or ACK frame (950) can be performed within a TXOP (925).

[0127] Figure 10 shows an example of channels used / supported / defined within the 2.4 GHz band.

[0128] The 2.4 GHz band may be referred to by other names, such as the first band (band). Furthermore, the 2.4 GHz band may refer to a frequency range in which channels with a center frequency adjacent to 2.4 GHz (e.g., channels with a center frequency between 2.4 and 2.5 GHz) are used / supported / defined.

[0129] The 2.4 GHz band may include multiple 20 MHz channels. The 20 MHz within the 2.4 GHz band may have multiple channel indices (e.g., indices 1 through 14). For example, the center frequency of a 20 MHz channel assigned channel index 1 may be 2.412 GHz, the center frequency of a 20 MHz channel assigned channel index 2 may be 2.417 GHz, and the center frequency of a 20 MHz channel assigned channel index N may be (2.407 + 0.005*N) GHz. The channel indices may be referred to by various names, such as channel numbers. The specific numerical values ​​of the channel indices and center frequencies may change.

[0130] Figure 10 exemplarily illustrates four channels within the 2.4 GHz band. The illustrated first frequency region (1010) to fourth frequency region (1040) may each include one channel. For example, the first frequency region (1010) may include channel 1 (a 20 MHz channel having an index of 1). In this case, the center frequency of channel 1 may be set to 2412 MHz. The second frequency region (1020) may include channel 6. In this case, the center frequency of channel 6 may be set to 2437 MHz. The third frequency region (1030) may include channel 11. In this case, the center frequency of channel 11 may be set to 2462 MHz. The fourth frequency region (1040) may include channel 14. In this case, the center frequency of channel 14 may be set to 2484 MHz.

[0131] Figure 11 illustrates an example of channels used / supported / defined within the 5 GHz band.

[0132] The 5 GHz band may be referred to by other names, such as a second band / band, etc. The 5 GHz band may refer to a frequency range in which channels with center frequencies greater than or equal to 5 GHz and less than 6 GHz (or less than 5.9 GHz) are used / supported / defined. Alternatively, the 5 GHz band may include multiple channels between 4.5 GHz and 5.5 GHz. The specific figures shown in FIG. 11 are subject to change.

[0133] Multiple channels within the 5 GHz band include Unlicensed National Information Infrastructure (UNII)-1, UNII-2, UNII-3, and ISM. UNII-1 may be referred to as UNII Low. UNII-2 may include frequency ranges called UNII Mid and UNII-2Extended. UNII-3 may be referred to as UNII-Upper.

[0134] Within the 5 GHz band, multiple channels can be configured, and the bandwidth of each channel can be variously configured, such as 20 MHz, 40 MHz, 80 MHz, or 160 MHz. For example, the 5170 MHz to 5330 MHz frequency domain / range within UNII-1 and UNII-2 can be divided into eight 20 MHz channels. The 5170 MHz to 5330 MHz frequency domain / range can be divided into four channels through a 40 MHz frequency domain. The 5170 MHz to 5330 MHz frequency domain / range can be divided into two channels through an 80 MHz frequency domain. Alternatively, the 5170 MHz to 5330 MHz frequency domain / range can be divided into one channel through a 160 MHz frequency domain.

[0135] Figure 12 illustrates an example of channels used / supported / defined within the 6 GHz band.

[0136] The 6 GHz band may also be referred to by other names, such as the third band / band. The 6 GHz band may refer to the frequency range in which channels with center frequencies above 5.9 GHz are used, supported, or defined. The specific figures shown in Figure 12 are subject to change.

[0137] For example, the 20 MHz channel of FIG. 12 can be defined from 5.940 GHz. Specifically, the leftmost channel among the 20 MHz channels of FIG. 12 can have an index of 1 (or channel index, channel number, etc.), and a center frequency of 5.945 GHz can be assigned. That is, the center frequency of the indexed channel N can be determined as (5.940 + 0.005*N) GHz.

[0138] Accordingly, the indexes (or channel numbers) of the 20 MHz channels of FIG. 12 are 1, 5, 9, 13, 17, 21, 25, 29, 33, 37, 41, 45, 49, 53, 57, 61, 65, 69, 73, 77, 81, 85, 89, 93, 97, 101, 105, 109, 113, 117, 121, 125, 129, 133, 137, 141, 145, 149, 153, 157, 161, 165, 169, 173, 177, 181, 185, 189, 193, It can be 197, 201, 205, 209, 213, 217, 221, 225, 229, 233. Also, according to the (5.940 + 0.005*N) GHz rule mentioned above, the indices of the 40 MHz channels in Fig. 12 can be 3, 11, 19, 27, 35, 43, 51, 59, 67, 75, 83, 91, 99, 107, 115, 123, 131, 139, 147, 155, 163, 171, 179, 187, 195, 203, 211, 219, 227.

[0139] Below, the structure and types / subtypes of MAC frames are described.

[0140] Fig. 13 illustrates an example of a header of a MAC frame. As illustrated, the MAC frame may include a frame control field / information of 2 octets in length, a duration field / information of 2 octets in length, a RA (Receiver Address) field / information of 6 octets in length, and a TA (Transmitter Address) field / information of 6 octets in length. As illustrated in Fig. 13, the four fields may be consecutive to each other. The MAC header of Fig. 13 may be modified in various ways, and a new field may be inserted between the four illustrated fields, or at least one of the illustrated fields may be omitted.

[0141] The MAC header illustrated in Fig. 13 may be positioned at the very front of a MAC frame. That is, the MAC frame may include a MAC header as illustrated in Fig. 13 and MAC body fields / information subsequent to the MAC header. The MAC frame including the MAC header of Fig. 13 is inserted / included in the data field of the PPDU (e.g., UHR PPDU) illustrated in Fig. 5.

[0142] The MAC frames included in the data field of the PPDU of this specification can be classified into various types. For example, the MAC frames of this specification can be classified into control frames, management frames, and data frames.

[0143] For example, the management frame includes Association Request, Association Response, Reassociation Request, Reassociation Response, Probe Request, Probe Response, Beacon, Disassociation, Authentication, and Deauthentication frames / signals defined in conventional WLAN. For the management frame, the values ​​of the type fields (B3 and B2) in FIG. 13 are set to 00. In addition, the values ​​of the subtype fields (B7, B6, B5, B4) in FIG. 13 are as follows: Association Request (0000), Association Response (0001), Reassociation Request (0010), Reassociation Response (0011), Probe Request (0100), Probe Response (0101), Beacon (1000), Disassociation (1010), Authentication (1011), Deauthentication (1100).

[0144] For example, the control frame includes Trigger Beamforming Report Poll, NDP Announcement (NDPA), Control Frame Extension, Control Wrapper, Block Ack Request (BlockAckReq), Block Ack (BlockAck), PS-Poll, RTS, CTS, Ack, and CF-End frames / signals defined in conventional WLAN. For the control frame, the value of the type field (B3 and B2) in FIG. 13 is set to 01. Also, the values ​​of the subtype fields (B7, B6, B5, B4) of FIG. 13 are as follows: Trigger (0010), Beamforming Report Poll (0100), NDP Announcement (0101), Control Frame Extension (0110), Control Wrapper (0111), BlockAckReq (1000), BlockAck (1001), PS-Poll (1010), RTS (1011), CTS (1100), Ack (1101), CF-End (1110).

[0145] For example, the data frame includes (QoS) Data, (QoS) Null, etc. defined in conventional WLAN. For the management frame, the value of the type field (B3 and B2) of Fig. 13 is set to 10.

[0146] The MAC frame / signal used in this specification can be identified through the type field / information and subtype field / information described above. For example, the “trigger frame” in this specification can mean a MAC frame in which the type bits B3 and B2 bits in the frame control field of the MAC header are set to 01, and the subtype bits B7, B6, B5, B4 bits in the frame control field are also set to 0010. Various MAC frames described in this specification are inserted / included in the data fields of various PPDUs (e.g., HE / VHT / HE / EHT / UHR PPDUs).

[0147] FIG. 14 illustrates a modified example of a transmitting device and / or a receiving device of the present specification.

[0148] The devices (e.g., AP STA, non-AP STA) illustrated in FIGS. 1 to 4 may be modified as illustrated in FIG. 14. The transceiver (630) of FIG. 14 may be identical to the transceivers (113, 123) of FIG. 1. The transceiver (630) of FIG. 14 may include a receiver and a transmitter.

[0149] The processor (610) of FIG. 14 may be identical to the processor (111, 121) of FIG. 1. Alternatively, the processor (610) of FIG. 14 may be identical to the processing chip (114, 124) of FIG. 1.

[0150] The memory (150) of FIG. 14 may be the same as the memory (112, 122) of FIG. 1. Alternatively, the memory (150) of FIG. 14 may be a separate external memory different from the memory (112, 122) of FIG. 1.

[0151] Referring to FIG. 14, a power management module (611) manages power to a processor (610) and / or a transceiver (630). A battery (612) supplies power to the power management module (611). A display (613) outputs results processed by the processor (610). A keypad (614) receives input to be used by the processor (610). The keypad (614) may be displayed on the display (613). A SIM card (615) may be an integrated circuit used to securely store an international mobile subscriber identity (IMSI) and an associated key used to identify and authenticate a subscriber in a mobile phone device, such as a mobile phone or computer.

[0152] Referring to FIG. 14, the speaker (640) can output sound-related results processed by the processor (610). The microphone (641) can receive sound-related input to be used by the processor (610).

[0153] The technical features of this specification are described in more detail below.

[0154] The maximum duration of a PPDU based on HT / VHT / HE / EHT / UHR can be up to 5.484 ms. For example, the IEEE 802.11 standard can determine the maximum duration of a PPDU based on a parameter called aPPDUmaxtime.

[0155] This specification may relate to a new type / format / category of PPDU that improves upon the conventional PPDU. For example, a PPDU of a new type / format / category related to the operation of this specification may be called by various names. For example, a PPDU related to the operation of this specification may be used by various names such as Small PPDU, Short PPDU, Low latency PPDU, TX PPDU, RX PPDU, 1st / 2nd PPDU, etc. In the following, the name Small PPDU is used for convenience of explanation, but the technical features of this specification are not limited to this name Small PPDU.

[0156] The small PPDU related to the present specification may have a maximum duration set shorter than that of a conventional PPDU. Additionally or alternatively, the small PPDU may have the same aPPDUmaxtime parameter as the conventional PPDU, but its duration may be set shorter than that of the conventional PPDU based on a parameter / field / subfield newly defined in the WIFI standard or a conventional parameter / field / subfield. Additionally or alternatively, the small PPDU may be a PPDU that does not include a Low-latency PPDU. For example, the Low-latency PPDU may be a PPDU that carries Low-latency traffic. The Low-latency traffic may be identified based on at least one of QoS / AC (Access category) / TID (Traffic ID) / Delay / latency assigned to the corresponding traffic. Additionally or alternatively, the small PPDU may mean a set of multiple PPDUs for which immediate ACK is not required and delayed ACK is allowed. Additionally or alternatively, the small PPDU may mean a PPDU configured based on a preamble having a new structure as presented in the present specification (e.g., a preamble in which the Legacy preamble is omitted as described below, or a preamble including only HE / EHT / UHR-LTF, or a preamble including only HE / EHT / UHR-STF and HE / EHT / UHR-LTF).The small PPDU of the present specification may include a preamble and a data field succeeding the preamble, and the data field may include a Physical Service Data Unit (PSDU). The small PPDU related to the present specification may be distinguished from a conventional PPDU based on at least one criterion / definition presented above. The conventional PPDU that is distinguished from the newly proposed PPDU (e.g., small PPDU) of the present specification may be called by various names. For example, various names such as long / large / legacy / HT / VHT / HE / EHT / UHR-PPDU may be used.

[0157] Additionally or alternatively, the small PPDU may be determined independently of the duration of the PPDU. For example, whether a PPDU is a small PPDU may be determined based on the physical version of the PPDU, or whether a PPDU is a small PPDU may be determined based on the type of the PPDU. In this case, information regarding the type of the PPDU may be included in the U-SIG field and / or the EHT / UHR-SIG field of the PPDU.

[0158] If the length (or duration) of a PPDU is set long, there may be advantages such as reduced contention and preamble overhead for channel occupation. However, if low-latency traffic occurs while a PPDU is being transmitted or received, the transmission / reception of the low-latency traffic cannot be performed immediately. In other words, the transmission / reception of the newly generated low-latency traffic must be performed after the transmission / reception of the existing PPDU is completed, resulting in a technical problem. For example, if the maximum length (or duration) of a conventional PPDU is set to 5.484 ms as described above, the maximum delay that can occur can be 5.484 ms. Furthermore, an STA wishing to transmit the low-latency traffic may need to perform a new contention to access the wireless channel.

[0159] This specification proposes the aforementioned small PPDU to address the technical issues associated with conventional PPDUs. For example, to address the problems associated with conventional PPDUs (e.g., the inability to immediately transmit low-latency traffic), this specification proposes a method of limiting the PPDU length and instead transmitting multiple PPDUs sequentially.

[0160] An example of FIG. 15 relates to an example of a PPDU proposed in this specification.

[0161] In an example of FIG. 15, communication in a BSS including AP1 (1500), STA1 (1501), and STA2 (1502) is described. For example, AP1 (1500) may be a TXOP holder defined in a conventional WIFI standard. For example, STA1 (1501) may be a TXOP responder defined in a conventional WIFI standard. The definition of TXOP holder / responder used in this specification may be the same as that of a conventional wireless LAN. For example, a TXOP holder may obtain / acquire a TXOP through a conventional RTS (request to send) / CTS (clear to send) exchange, or may obtain a TXOP through various methods, such as a method of transmitting a PPDU and receiving an ACK for it. The TXOP holder may be an AP or a non-AP. For convenience of explanation, a TXOP acquired by an AP may be expressed by various names such as DL-TXOP, and a TXOP acquired by a non-AP may be expressed by various names such as UL-TXOP. For example, a TXOP responder may mean an STA that can receive a response frame for a frame received from a TXOP holder during a frame exchange sequence, but does not acquire a TXOP in a related processor. For example, a TXOP responder may be an AP or a non-AP. In the example of FIG. 15, STA2 (1502) may be a BSS STA that is neither a TXOP holder nor a TXOP responder.

[0162] For example, as shown in FIG. 15, a TXOP holder (e.g., AP1) may transmit multiple Small PPDUs in succession after acquiring a TXOP. Afterwards, a) a Low Latency (LL) PPDU may occur, b) a response (e.g., an ACK) to the LL PPDU may need to be transmitted / received, and / or c) transmission / reception of other other PPDU(s) may be required.

[0163] More specifically, in the example of FIG. 15, AP1 (1500) can acquire a TXOP according to a conventional method. During the same TXOP, AP1 (1500) can transmit at least one or more small PPDUs (1501, 1502) to STA1 (1501), which is a TXOP responder. In this case, the multiple small PPDUs (1501, 1502) can be transmitted sequentially. That is, an immediate ACK may not be received after the first small PPDU (1501) is transmitted, and the IFS (Interframe space) between the multiple small PPDUs can be the SIFS (Interframe space) of the conventional WIFI / wireless LAN standard.

[0164] As illustrated, LL (low latency) traffic may be generated (1530) in AP1 (1500), which is a TXOP holder. In this case, the LL traffic may need to be transmitted to STA2 (1502), not STA1 (1501), which is a TXOP responder. Accordingly, AP1 (1500), which is a TXOP holder, may transmit an LL PPDU (1540) related to the LL traffic to STA2 (1502). In this case, a preemption technique / technology / method may be applied to STA2 (1502), and based on this preemption technique / technology / method, STA2 (1502) may transmit an ACK / BA (1550) for the LL PPDU (1540) to AP1 (1500) during the TXOP, even though it is not a TXOP responder. Afterwards, AP1 (1500), which is the TXOP holder, may transmit an additional small PPDU (1560). The ACK for at least one small PPDU (1510, 1520, 1560) transmitted by AP1 (1500), which is the TXOP holder, may be transmitted in the form of a delayed ACK. That is, the ACK (1570) transmitted by STA1 (1501) may be delivered to AP1 (1500) after a duration equal to SIFS has elapsed from the last small PPDU (1560).

[0165] Hereinafter, technical features applied to small PPDUs used in this specification are described. The small PPDUs of this specification are not limited to the example of FIG. 15. For example, the small PPDUs of this specification may be used not only in a situation where a DL-TXOP is acquired as in FIG. 15, but also in a situation where a UL-TXOP is acquired. For example, the small PPDUs of this specification may be used not only by a TXOP holder as in FIG. 15, but also by a TXOP responder, or a normal AP (or non-AP) that is not a TXOP holder / responder.

[0166] Figure 16 illustrates an example of a typical PPDU. As illustrated, a Preamble (1610) is configured at the very front of the PPDU. Furthermore, the PPDU may include a Data field (1620) that follows the Preamble (1610). Furthermore, the PPDU may include a Packet Extension (PE) field (1630) that follows the Data field (1620).

[0167] Figure 17 illustrates a specific example of a preamble included in a PPDU. Each detailed field in Figure 17 may be based on the preamble of an EHT-MU PPDU.

[0168] For example, L-STF (1710), L-LTF (1720), L-SIG (1730), RL-SIG (1740), U-SIG (1750) of FIG. 17 may be identical to L-STF, L-LTF, L-SIG, RL-SIG, U-SIG described in FIG. 5, respectively. For example, EHT-SIG (1760), EHT-STF (1770), EHT-LTF (1780) of FIG. 17 may be identical to UHR-SIG, UHR-STF, UHR-LTF described in FIG. 5, respectively.

[0169] For example, the Preamble configuration of the Small PPDU of the present specification may be based on the Preamble of the EHT MU PPDU or UHR PPDU illustrated in FIG. 17 and / or FIG. 5. For example, the names and configurations of the U-SIG (1750) and EHT-SIG / STF / LTF (1760, 1770, 1780) illustrated in FIG. 17 may be changed.

[0170] Below, specific technical features applicable to the Small PPDU of this specification are described.

[0171] Technical Features-1.

[0172] As previously explained, when transmitting multiple small PPDUs instead of a single long PPDU (i.e., a conventional PPDU, not a small PPDU in this specification), technical problems may arise due to the presence of multiple small PPDUs. For example, if multiple small PPDUs exist instead of a single long PPDU, a time interval of xIFS (e.g., SIFS, PIFS) may exist between the multiple small PPDUs, and radio / time / frequency resources may be wasted due to these multiple time intervals. In addition, if the preamble is repeated for each multiple small PPDU, radio / time / frequency resources may be wasted due to these repeated preambles. This specification proposes the following various technical features to minimize such waste of radio / time / frequency resources. Hereinafter, an example of a method for configuring a preamble of a small PPDU and the operation of STAs according to the method will be described. The xIFS described in the example below may be a SIFS or PIFS (priority interframe space) defined according to a conventional wireless LAN standard.

[0173] Technical Features-2.

[0174] For example, the Small PPDU of this specification may be structured as follows. For example, the preamble illustrated in FIGS. 5 / 16 / 17 may be omitted, and the PPDU may start directly from the Data field / part.

[0175] Technical Features-2.1.

[0176] As described above, the small PPDU of the present specification can be transmitted directly from the Data field / part without a Preamble. In this case, information regarding the configuration of the small PPDU (e.g., information indicated by U-SIG or EHT-SIG, such as RU configuration, SS number, MCS, etc.) can be transmitted in advance to the STA receiving the small PPDU. That is, the STA transmitting the small PPDU (e.g., AP, non-AP, TXOP holder, TXOP responder, etc.) can transmit information regarding the configuration of the small PPDU to the intended recipient of the small PPDU (e.g., AP, non-AP, TXOP holder, TXOP responder, etc.). The information regarding the configuration of the small PPDU can be transmitted in various ways. For example, the information regarding the configuration of the small PPDU can be included in the PPDU transmitted first within the TXOP in which the small PPDU(s) are transmitted (i.e., the initial PPDU). For example, the information regarding the configuration of the small PPDU may be configured as 1 / 2 / 3 bit (or n bit) information in the U-SIG field (or EHT-SIG / UHT-SIG) included in the PPDU transmitted first (i.e., initial PPDU) within the TXOP through which the small PPDU(s) are transmitted. For example, the information regarding the configuration of the small PPDU may be included in a management frame generated before the TXOP through which the small PPDU(s) are transmitted is acquired, and the management frame may be transmitted in advance to the intended recipient of the small PPDU. The information regarding the configuration of the small PPDU may include various control information / bits.For example, the information about the configuration of the small PPDU may include information about RUs applied to a data field of the small PPDU (the first small PPDU transmitted, or the subsequent small PPDU transmitted after the present time) (e.g., information about the maximum / minimum number of tones of the RUs allocated to the small PPDU, information about the frequency / subchannel band of the allocated RU, etc.). For example, the information about the configuration of the small PPDU may include information about SSs (Spatial streams) applied to a data field of the small PPDU (the first small PPDU transmitted, or the subsequent small PPDU transmitted after the present time) (e.g., information about the number of SSs allocated, and the maximum / minimum number of SSs that can be allocated). For example, information about the configuration of the small PPDU may include information about an MCS applied to a data field of the small PPDU (the first small PPDU transmitted, or a subsequent small PPDU transmitted after the current point in time) (e.g., MCS or Modulation order or coding type information applied to the data field and / or a specific RU).

[0177] The fields included in the Small PPDU of this specification may be configured differently depending on the order in which they are transmitted within the TXOP. For example, when two small PPDUs are transmitted within the TXOP, the first Small PPDU among the two small PPDUs (i.e., the small PPDU transmitted first or the initial PPDU transmitted first within the TXOP) may be based on the EHT / UHR (or future version) PPDU format including the entire Preamble. That is, the first Small PPDU among the two small PPDUs (i.e., the small PPDU transmitted first or the initial PPDU transmitted first within the TXOP) may include all of L-STF, L-LTF, L-SIG, RL-SIG, U-SIG, EHT / UHR-SIG, EHT / UHR-STF, and EHT / UHR-LTF as illustrated in FIG. 5 / 17, etc. For example, among two small PPDUs, the second Small PPDU (i.e., the small PPDU transmitted later or the non-initial PPDU within the TXOP) may not include a preamble in the PPDU but may include a data field. If the second Small PPDU (i.e., the small PPDU transmitted later or the non-initial PPDU within the TXOP) does not include a preamble, the PPDU configuration method applied to the second small PPDU (e.g., the configuration method for SS / RU / MCS applied to the data field) may be the same as the configuration method applied to the first small PPDU. As another example, the TXOP holder may announce the configuration (e.g., the RU configuration, the number of SSs, and the MCS information described above) before transmitting the Small PPDU.

[0178] Below, the operation of the receiving STAs is described.

[0179] Technical Features-2.1.1.

[0180] The technical features described below can be performed together with the technical feature-2.1 described above, or can be performed independently of the technical feature-2.1 described above.

[0181] An (RX) STA that knows the configuration information in advance can start data decoding immediately at the expected start time of the PPDU (e.g., after the xIFS of the previous PPDU). For example, an STA that has already received configuration information including its STA-ID can read the MAC header of the received small PPDU and read / decode data. For example, STAs that do not include their STA-ID in the received configuration information in advance can read the MAC header of the received small PPDU, obtain the duration field value included in the MAC header, and set the NAV based on the obtained duration value. This NAV setting process may be identical to the NAV setting of the conventional WLAN standard. If a decoding operation is performed but a decoding fail occurs, the conventional PPDU detection procedure defined in the conventional WLAN standard may be additionally performed.

[0182] Technical Features-2.1.2.

[0183] The following technical features can be applied to STAs that do not have prior configuration information. The technical features described below can be implemented in conjunction with or independently of Technical Feature 2.1 described above.

[0184] STAs that do not know the configuration information in advance can perform the conventional PPDU detection procedure defined in existing wireless LAN standards from the beginning. However, because the small PPDUs received by the STA may not contain preamble information, NAV setting may not be performed throughout the small PPDU transmission period due to continued preamble detection failures. In this case, the receiving STA may continue to attempt preamble detection, resulting in detection overhead.

[0185] Technical Features - 2.1.3.

[0186] The following technical features can be applied to OBSS (overlapping BSS) STAs. The technical features described below can be performed together with the previously described technical feature-2.1 (and / or technical feature-2.1.1, technical feature-2.1.2), or can be performed independently of the previously described technical features. For example, the STA and AP illustrated in FIG. 15 can be BSS STAs, and the OBSS may not be indicated in FIG. 15. That is, the STA described below can be applied to OBSS STAs (APs and / or non-APs) included in an OBSS adjacent to a BSS including an AP / STA in FIG. 15.

[0187] For example, an OBSS STA can set a basic NAV from the time of setting a BSS TXOP. This basic NAV setting can be performed according to a conventional wireless LAN standard. For example, when a TXOP is acquired by AP1 (1500) of FIG. 15, the TXOP can be called a BSS TXOP. An OBSS STA (not shown in FIG. 15) can set a basic NAV based on a duration field included in a packet used in the process of acquiring the TXOP of FIG. 15. For example, the basic NAV can be set based on a duration field included in a CTS / RTS used in the process of acquiring the TXOP of FIG. 15, or the basic NAV can be set based on a duration field included in a typical packet used in the process of acquiring the TXOP of FIG. 15. When the basic NAV is set within the OBSS STA as described above, the OBSS STA may not be able to transmit a PPDU within the OBSS while the basic NAV is set (i.e., while the BSS TXOP is set). However, a special reuse (SR) technique may be applied to the OBSS STA so that the OBSS STA can transmit a PPDU within the OBSS even while the basic NAV is set (i.e., while the BSS TXOP is set). That is, the OBSS STA can transmit a PPDU within the OBSS even while the BSS TXOP is set by using the SR technique. Specifically, the OBSS STA can determine whether the surrounding wireless channel is busy or idle based on the OBSS PD (Power Detection) level. The OBSS PD level related to the SR technique may have a threshold set higher than a normal PD level (for example, a threshold set that is 10 dBm higher than the conventional one).Through this, the OBSS STA can determine the wireless channel, which is determined to be busy if it were a conventional PD level, as idle. The OBSS STA applying the OBSS PD level as described above can transmit a PPDU within the OBSS based on the transmission power set based on the threshold value of the increased PD level. For example, according to the SR technique described above, if the threshold value of the PD level increases by 10 dBm, the maximum value of the transmission power applied to the OBSS STA can be reduced by 10 dBm. In this way, the OBSS STA can transmit a PPDU based on the maximum value of the increased PD Level (i.e., OBSS PD level) and the reduced transmission power within the OBSS even while the basic NAV is being set (i.e., while the BSS TXOP is being set).

[0188] Technical Features-2.2.

[0189] The technical feature-2 described above (i.e., technical feature-2.1, technical feature-2.1.1, technical feature-2.1.2, and / or technical feature-2.1.3) may be modified in various ways. The technical features described below describe examples of various modifications of the above-described technical feature-2 (i.e., technical feature-2.1, technical feature-2.1.1, technical feature-2.1.2, and / or technical feature-2.1.3).

[0190] AGC, Timing sync, CFO, channel estimation, etc. required for data decoding may be based on the EHT-STF / LTF (or UHR-STF / LTF, etc.) of the previous PPDU (e.g., the PPDU immediately before the currently received small PPDU) or the first Small PPDU (e.g., the initial PPDU in the TXOP). However, for more accurate performance, each Small PPDU (or all small PPDUs in the TXOP) may include EHT-STF and / or EHT-LTF (or UHR-STF / LTF, etc.). For example, if the Small PPDU in the present specification includes EHT-STF and / or EHT-LTF (or UHR-STF / LTF, etc.), not all small PPDUs need to include EHT-STF and / or EHT-LTF (or UHR-STF / LTF, etc.). For example, only every N (for example, N is a natural number greater than 1 (e.g., 2, 3, 4, N, etc.)) small PPDUs within a TXOP may include the EHT-STF and / or EHT-LTF (or UHR-STF / LTF, etc.). Alternatively, EHT-STF and / or EHT-LTF (or UHR-STF / LTF, etc.) may be included for small PPDUs transmitted or received immediately after LL PPDUs are transmitted or received, and EHT-STF and / or EHT-LTF (or UHR-STF / LTF, etc.) may be omitted for other small PPDUs. When small PPDUs are transmitted or received consecutively, the possibility of the radio channel changing between each PPDU is low, so there is no need to always include STF / LTF in the small PPDUs. However, when LL PPDUs are inserted, the possibility of the radio channel changing before and after the transmission or reception of the LL PPDU is high.That is, since a small PPDU transmitted or received after an LL PPDU is likely to experience a different wireless channel than a small PPDU transmitted or received earlier, a small PPDU transmitted or received immediately after an LL PPDU may necessarily include EHT-STF and / or EHT-LTF (or UHR-STF / LTF, etc.).

[0191] Technical Features-3.

[0192] The above-described Technical Feature-2 (i.e., Technical Feature-2.1, Technical Feature-2.1.1, Technical Feature-2.1.2, Technical Feature-2.1.3, and / or Technical Feature-2.2, etc.) relates to the case where the preamble part is omitted entirely or only the STF / LTF signal is included in the preamble part. However, since the existing L-STF, L-LTF, L-SIG (i.e., the L-preamble part) are fields that can be recognized by the conventional legacy wireless LAN STA, the L-preamble part may be forced in the small PPDU of the present specification. The following Technical Feature-3.1 (i.e., Technical Feature-3.1.1 to Technical Feature-3.1.4) relates to an example where the L-preamble part is included.

[0193] Technical Features-3.1.

[0194] For example, if at least two small PPDUs are transmitted sequentially, L-STF / L-LTF / L-SIG may be enforced from the second Small PPDU onwards. The Data field may be located immediately after the L-SIG field within the PPDU. For example, if at least two small PPDUs are transmitted sequentially, the first Small PPDU (i.e., the small PPDU transmitted first or the initial PPDU transmitted first within the TXOP) may be based on the EHT / UHR (or future version) PPDU format including the entire Preamble. That is, among the two small PPDUs, the first Small PPDU (i.e., the small PPDU transmitted first or the initial PPDU transmitted first within the TXOP) may include all of L-STF, L-LTF, L-SIG, RL-SIG, U-SIG, EHT / UHR-SIG, EHT / UHR-STF, and EHT / UHR-LTF as shown in FIG. 5 / 17, etc.

[0195] CFO correction and channel information required for data decoding of the above-mentioned second small PPDU may utilize EHT-STF / LTF (or UHR-STF / LTF, etc.) included in the above-mentioned first small PPDU.

[0196] Technical Features-3.1.1.

[0197] Even if the above-described technical feature-3.1 is applied, the operation of the above-described STA (i.e., the operation of the STA described in the above-described technical feature-2.1.1, technical feature-2.1.2, and technical feature-2.1.3) can be applied in the same manner.

[0198] Technical Features - 3.1.2.

[0199] However, STAs that do not know the configuration information in advance can set the NAV by looking at the L-SIG information of the Small PPDU, which can reduce the detection overhead compared to the above method.

[0200] Technical Features-3.1.3.

[0201] When the L-part preamble is included as in the above-described technical feature-3.1, the small PPDU may additionally include EHT-STF and / or EHT-LTF (or UHR-STF / LTF, etc.) for the reasons introduced in the above-described technical feature-2.2.

[0202] Technical Features - 3.1.4.

[0203] If the U-SIG includes information such as Small PPDU (or an indication that a Low Latency PPDU / packet is transmitted within the corresponding TXOP), the small PPDU of this specification may include the U-SIG field in addition to the L-preamble part. In this case, when a PPDU including the above-described information (i.e., U-SIG) is received, the receiving PPDU can determine that the received signal is a Small PPDU, and therefore, the STA (including the OBSS STA) that must transmit the Low Latency packet / PPDU can attempt to transmit the Low latency packet / PPDU. For example, the information (information indicating a small PPDU / LL PPDU) may be included in the MAC header of the data field instead of the U-SIG. In this case, the receiving STA can attempt to transmit the Low latency packet / PPDU regardless of the presence of the U-SIG through the information included in the MAC header. Additionally or alternatively, the PPDU length of the Small PPDU may be fixed. The receiving STA can read / obtain only information about the fixed PPDU length and then set NAV (or defer decoding) for that length.

[0204] The content of the above-described technical feature-3.1.4 can be applied in various ways. For example, the content of the above-described technical feature-3.1.4 can be applied even when only the L-preamble part is included, or even when the L-preamble part is omitted.

[0205] Technical Features-4.

[0206] Additional technical features described below may be applied to the contents of the above-described technical features-1 to-3.

[0207] For example, when multiple small PPDUs are transmitted within one TXOP, the first small PPDU and the subsequent small PPDUs may be PPDUs with the same Receive Address (RA). For example, when multiple small PPDUs related to an MU are transmitted within one TXOP (i.e., each of the multiple small PPDUs is delivered to a multi-user), the BSS Color and STA-ID included in each small PPDU may be the same, or the information included in the U-SIG and EHT-SIG of each small PPDU may be the same.

[0208] When multiple small PPDUs are transmitted within a single TXOP, the technical features of the small PPDU proposed in this specification may not be applied to all of the small PPDUs. For example, the technical features of the small PPDU proposed in this specification may not be applied to the first small PPDU (e.g., initial PPDU) or the last small PPDU within a single TXOP. In other words, the small PPDU (e.g., initial PPDU or last PPDU within a TXOP) may follow the structure of the EHT / UHR-PPDU described in FIG. 5 / 17, etc.

[0209] The above-described technical features can be explained based on the following flowchart.

[0210] Figure 18 is an example of a procedure flowchart of this specification.

[0211] Each step of FIG. 18 may be performed by various STAs (AP-STA, Relay STA, non-AP STA) of the WLAN system. For example, each step of FIG. 18 may be performed by a TXOP holder. For example, the TXOP holder may be an AP (Access Point) STA (station) or a non-AP STA. In other words, each step of FIG. 18 may be performed by an AP STA rather than a TXOP holder, or by a non-AP STA.

[0212] As illustrated in step S1810, a step of transmitting control information regarding a small PPDU (Physical Protocol Data Unit) may be performed.

[0213] For example, the control information regarding the small PPDU (Physical Protocol Data Unit) may be based on the contents described in the above-described technical feature-2.1. That is, it may include information regarding an RU applied to a data field of the small PPDU (the first small PPDU transmitted, or the subsequent small PPDU transmitted after the present time) (e.g., information regarding the maximum / minimum number of tones of the RU allocated to the small PPDU, information regarding the frequency / subchannel band of the allocated RU, etc.). For example, the information regarding the configuration of the small PPDU may include information regarding an SS (Spatial stream) applied to a data field of the small PPDU (the first small PPDU transmitted, or the subsequent small PPDU transmitted after the present time) (e.g., information regarding the number of SSs allocated, and the maximum / minimum number of SSs that can be allocated).

[0214] For example, the control information regarding the small PPDU (Physical Protocol Data Unit) can be transmitted in various ways. For example, the control information regarding the small PPDU (Physical Protocol Data Unit) can be transmitted before the TXOP related to step S1810 is acquired. For example, as described in the technical feature-2.1 described above, the control information regarding the small PPDU (Physical Protocol Data Unit) can be transmitted before the TXOP is acquired. Alternatively, the control information regarding the small PPDU (Physical Protocol Data Unit) can be transmitted through a specific PPDU (e.g., an initial PPDU or a non-initial PPDU transmitted Nth within the corresponding PPDU) within the acquired TXOP.

[0215] As illustrated in step S1820, a first PPDU may be transmitted within the already acquired TXOP. This first PPDU may be the small PPDU described in this specification. That is, as in the technical feature-2.1 described above, the first small PPDU (i.e., initial PPDU) within the TXOP may be configured in a format including all fields illustrated in FIG. 5 / FIG. 17, etc. That is, the PPDU of step S1820 (e.g., the first PPDU) may include an L-STF (Legacy Short Training Field), an L-LTF (Legacy Long Training Field), an L-SIG (Legacy Signal) field, an RL-SIG (Repeated L-SIG) field, a U-SIG (Universal Signal) field, an STF (Short Training Field), an LTF (Long Training Field), and a data field. Each field / signal listed above can be arranged sequentially as illustrated in FIG. 5 / 17, and the fields / signals listed above can be consecutive to each other as illustrated in FIG. 5 / 17. The PPDU of step S1820 can be configured based on the small PDU defined in this specification. That is, the PPDU of step S1820 can have at least one of the technical features described in Technical Features-2 to Technical Features-4 (and their detailed features) described above. As described above, the small PPDU can be called by various names. Accordingly, the PPDU of step S1820 can be called by various names such as first / second, TX / RX PPDU, short PPDU, etc., instead of the name small PPDU.

[0216] As illustrated in step S1830, a second PPDU may be transmitted. The second PPDU may be configured based on a small PDU defined in this specification. That is, the PPDU of step S1820 may have at least one of the technical features described in the above-described technical features-2 to-4 (and their detailed features), and accordingly, the second PPDU of step S1830 may not include the L-STF, the L-LTF, the L-SIG field, and the RL-SIG field. For example, the second PPDU of step S1830 may include EHT-STF / LTF (or UHR-STF / LTF, etc.) according to the above-described technical feature-2.2. Additionally or alternatively, the second PPDU of step S1830 may include the U-SIG field described in the above-described technical feature-3.1.4.

[0217] The PPDU transmitted through step S1820 and / or step S1830 may be configured based on the control information transmitted through step S1810. For example, information applied to the data field of the PPDU transmitted through step S1820 and / or step S1830 (e.g., Resource Unit (RU), Spatial Stream (SS), and / or Modulation and Coding Scheme (MCS)) may be based on the control information transmitted in step S1810.

[0218] As described in Technical Feature-4 above, the RA applied to PPDUs transmitted through steps S1820 and S1830 may be identical. For example, the BSS color, STA-ID, etc. applied to PPDUs transmitted through steps S1820 and S1830 may be determined identically.

[0219] For example, PPDUs transmitted through steps S1820 and S1830 can be delivered to the TXOP responder.

[0220] For example, PPDUs transmitted through steps S1820 and S1830 may be consecutive within the same TXOP. That is, the interframe space (IFS) between PPDUs transmitted through steps S1820 and S1830 may be set to the shot interframe space (SIFS).

[0221] For example, PPDUs transmitted through steps S1820 and S1830 may not be consecutive within the same TXOP. That is, after the PPDU of step S1820 is transmitted, the TXOP holder may transmit an LL PPDU. In this case, the IFS (interframe space) between the PPDU of step S1820 and the LL PPDU may be set to SIFS (Shot interframe space).

[0222] Figure 19 is an example of a procedure flowchart of this specification.

[0223] Each step of FIG. 19 may be performed by various STAs (AP-STA, Relay STA, non-AP STA) of the WLAN system. For example, each step of FIG. 19 may be performed by a TXOP responder. For example, the TXOP responder may be an AP (Access Point) STA (station) or a non-AP STA.

[0224] To avoid redundant explanations, the features of each step of FIG. 19 are described below based on FIG. 18. For example, the technical features applied to the illustrated step S1910 may be identical to the technical features of the illustrated step S1810. In addition, the technical features applied to the illustrated step S1920 may be identical to the technical features of the illustrated step S1820. In addition, the technical features applied to the illustrated step S1930 may be identical to the technical features of the illustrated step S1830.

[0225] The technical features of the present specification (e.g., the technical features described in at least one of FIGS. 15 to 19) may be implemented by various devices. The devices of the present specification may be the devices described in FIGS. 1 and 14. The devices of the present specification may include at least one processor; and at least one computer memory operably connectable to the at least one processor, the computer memory storing instructions that perform operations based on being executed by the at least one processor.

[0226] For example, the processor may be a processor described in FIG. 1 and / or FIG. 14. That is, as described above, the processor of the present specification may include at least one of a digital signal processor (DSP), a central processing unit (CPU), a graphics processing unit (GPU), and a modem (modulator and demodulator). The processor may include not only computers having various architectures such as single / multiprocessor architecture, sequential (Von Neumann) / parallel architecture, but also specialized circuits such as FPGAs, ASICs, signal processing devices, and other devices. For example, the processor of the present specification may be a SNAPDRAGON® series processor manufactured by Qualcomm®, an EXYNOS® series processor manufactured by Samsung®, an A series processor manufactured by Apple®, a HELIO® series processor manufactured by MediaTek®, an ATOM® series processor manufactured by INTEL®, or a processor that enhances the same.

[0227] For example, the instructions may refer to computer program instructions executed by the at least one processor. The (computer program) instructions provide logic and / or routines that enable the technical features of the present specification (the technical features described in at least one of FIGS. 15 to 19) to be performed by the processor. The at least one processor can load and execute a computer program by reading the at least one memory.

[0228] The computer program(s) defined by the above instructions may be delivered to the device (e.g., STA) of the present specification via an appropriate delivery mechanism. The delivery mechanism may be, for example, a computer-readable storage medium, a computer program product, a memory device, a recording medium such as a CD-ROM or DVD, or a product tangibly embodying the computer program. The delivery mechanism may be a signal configured to reliably transmit the computer program via a wireless or electrical connection.

[0229] The above (computer program) instructions may include software or firmware for a programmable processor (e.g., programmable content of a hardware device whether instructions for a processor, or configuration settings for a fixed-function device, gate array or programmable logic device, etc.).

[0230] For example, the memory may be the memory described in FIG. 1 and / or FIG. 14. That is, as described above, the memory of the present specification may store control information related to the operation of the STA of the present specification or information about signals transmitted and received by the STA (e.g., PPDU including management / control / data frames).

[0231] The technical features of this specification may be implemented in at least one computer-readable recording medium (CRM). The CRM includes instructions that are executed by at least one processor as described above. The instructions stored in the CRM may be computer program instructions as described above.

[0232] The device of the present disclosure may further include a transceiver. The transceiver may be operably connectable to the memory / processor, etc. The transceiver may be the transceiver illustrated in FIG. 1 and / or FIG. 14.

[0233] The technical features of this specification described above are applicable to various applications and business models. For example, the technical features described above can be applied to wireless communication in devices that support artificial intelligence (AI).

[0234] Artificial intelligence (AI) is the study of artificial intelligence or the methodologies for creating it, while machine learning (ML) defines various problems in the field of AI and studies the methodologies for solving them. Machine learning is also defined as an algorithm that improves performance on a task through consistent experience.

[0235] An artificial neural network (ANN) is a model used in machine learning. It can refer to a model with problem-solving capabilities, consisting of artificial neurons (nodes) formed by the connection of synapses to form a network. An ANN can be defined by the connection patterns between neurons in different layers, the learning process that updates model parameters, and the activation function that generates output values.

[0236] An artificial neural network may include an input layer, an output layer, and optionally one or more hidden layers. Each layer contains one or more neurons, and the artificial neural network may include synapses connecting neurons. In an artificial neural network, each neuron can output a function value of an activation function based on input signals, weights, and biases received through the synapses.

[0237] Model parameters are parameters determined through learning, including synaptic connection weights and neuron biases. Hyperparameters are parameters that must be set before learning in machine learning algorithms, including the learning rate, number of iterations, mini-batch size, and initialization function.

[0238] The goal of learning an artificial neural network can be seen as determining model parameters that minimize a loss function. The loss function can be used as an indicator for determining optimal model parameters during the learning process of an artificial neural network.

[0239] Machine learning can be classified into supervised learning, unsupervised learning, and reinforcement learning depending on the learning method.

[0240] Supervised learning refers to a method for training an artificial neural network when given labels for the training data. The labels can refer to the correct answer (or output value) that the artificial neural network must infer when the training data is input to the artificial neural network. Unsupervised learning can refer to a method for training an artificial neural network when the training data is not given labels. Reinforcement learning can refer to a learning method in which an agent defined within a given environment is trained to select actions or action sequences that maximize the cumulative reward in each state.

[0241] Machine learning implemented with a deep neural network (DNN) containing multiple hidden layers among artificial neural networks is also called deep learning, and deep learning is a subset of machine learning. Hereinafter, the term "machine learning" is used to encompass deep learning.

[0242] Additionally, the above-described technical features can be applied to wireless communication of robots.

[0243] A robot can be defined as a machine that automatically performs or operates a given task based on its own capabilities. Specifically, a robot capable of perceiving its environment, making independent judgments, and performing actions can be called an intelligent robot.

[0244] Robots can be categorized into industrial, medical, household, and military applications based on their intended use or field. Robots are equipped with actuators or motors, enabling them to perform various physical actions, such as moving robot joints. Furthermore, mobile robots incorporate wheels, brakes, and propellers into their actuators, enabling them to move on the ground or fly in the air.

[0245] Additionally, the above-described technical features can be applied to devices that support extended reality.

[0246] Extended reality is a general term for virtual reality (VR), augmented reality (AR), and mixed reality (MR). VR technology presents real-world objects and backgrounds as CG images only, AR technology presents virtual CG images over images of real objects, and MR technology is a computer graphics technology that blends and combines virtual objects with the real world.

[0247] MR technology is similar to AR in that it presents both real and virtual objects simultaneously. However, while AR uses virtual objects to complement real objects, MR uses virtual and real objects on an equal footing.

[0248] XR technology can be applied to HMD (Head-Mount Display), HUD (Head-Up Display), mobile phones, tablet PCs, laptops, desktops, TVs, digital signage, etc., and devices to which XR technology is applied can be called XR devices.

Claims

1. A method performed in a wireless local area network (WLAN) system, A step of transmitting control information regarding a small PPDU (Physical Protocol Data Unit) by a TXOP holder who has acquired a TXOP (transmission opportunity); A step of transmitting a first PPDU by the TXOP holder within the TXOP, wherein the first PPDU includes an L-STF (Legacy Short Training Field), an L-LTF (Legacy Long Training Field), an L-SIG (Legacy Signal) field, an RL-SIG (Repeated L-SIG) field, a U-SIG (Universal Signal) field, an STF (Short Training Field), an LTF (Long Training Field), and a data field, and wherein the first PPDU is configured based on the small PPDU; and A step of transmitting a second PPDU by the TXOP holder within the TXOP after transmitting the first PPDU, wherein the second PPDU does not include the L-STF, the L-LTF, the L-SIG field, and the RL-SIG field, and the second PPDU is configured based on the small PPDU. How to include.

2. In the first paragraph, the TXOP holder is an AP (Access Point) STA (station) or a non-AP STA. method.

3. In the first paragraph, the control information regarding the small PPDU is information regarding at least one of the RU (Resource Unit), SS (Spatial Stream), and / or MCS (modulation and coding scheme) applied to the data field of the PPDU. method.

4. In the first paragraph, the RU (Resource Unit), SS (Spatial Stream), and / or MCS (modulation and coding scheme) applied to the data fields of the first PPDU and the second PPDU are determined based on control information regarding the small PPDU. method.

5. In the first paragraph, the first PPDU and the second PPDU are transmitted to a TXOP responder related to the TXOP. method.

6. In the first paragraph, the IFS (interframe space) between the first PPDU and the second PPDU is set to SIFS (Shot interframe space). method.

7. For TXOP holders who have acquired a transmission opportunity (TXOP) in a wireless local area network (WLAN) system, at least one processor; and At least one computer memory operable to said at least one processor, said memory storing instructions for performing operations based on being executed by said at least one processor, The instructions of at least one computer memory are: A step of transmitting control information regarding a small PPDU (Physical Protocol Data Unit); A step of transmitting a first PPDU within the TXOP, wherein the first PPDU includes an L-STF (Legacy Short Training Field), an L-LTF (Legacy Long Training Field), an L-SIG (Legacy Signal) field, an RL-SIG (Repeated L-SIG) field, a U-SIG (Universal Signal) field, an STF (Short Training Field), an LTF (Long Training Field), and a data field, and wherein the first PPDU is configured based on the small PPDU; and A step of transmitting a second PPDU within the TXOP after transmitting the first PPDU, wherein the second PPDU does not include the L-STF, the L-LTF, the L-SIG field, and the RL-SIG field, and the second PPDU is configured based on the small PPDU. to perform TXOP holder.

8. In paragraph 7, The instructions of at least one computer memory are configured to further perform the steps of claims 2 to 6. TXOP holder.

9. In a method performed in a wireless local area network (WLAN) system, A step of receiving control information regarding a small PPDU (Physical Protocol Data Unit) from a TXOP holder that has acquired a TXOP (transmission opportunity); A step of receiving a first PPDU from the TXOP holder within the TXOP, wherein the first PPDU includes an L-STF (Legacy Short Training Field), an L-LTF (Legacy Long Training Field), an L-SIG (Legacy Signal) field, an RL-SIG (Repeated L-SIG) field, a U-SIG (Universal Signal) field, an STF (Short Training Field), an LTF (Long Training Field), and a data field, and wherein the first PPDU is configured based on the small PPDU; and A step of receiving a second PPDU by the TXOP holder within the TXOP after receiving the first PPDU, wherein the second PPDU does not include the L-STF, the L-LTF, the L-SIG field and the RL-SIG field, and the second PPDU is configured based on the small PPDU. How to include.

10. In a TXOP responder that communicates with a TXOP holder that has acquired a transmission opportunity (TXOP) in a wireless local area network (WLAN) system, at least one processor; and At least one computer memory operable to said at least one processor, said memory storing instructions for performing operations based on being executed by said at least one processor, The instructions of at least one computer memory are: A step of receiving control information regarding a small PPDU (Physical Protocol Data Unit) from the TXOP holder; A step of receiving a first PPDU from the TXOP holder within the TXOP, wherein the first PPDU includes an L-STF (Legacy Short Training Field), an L-LTF (Legacy Long Training Field), an L-SIG (Legacy Signal) field, an RL-SIG (Repeated L-SIG) field, a U-SIG (Universal Signal) field, an STF (Short Training Field), an LTF (Long Training Field), and a data field, and wherein the first PPDU is configured based on the small PPDU; and A step of receiving a second PPDU by the TXOP holder within the TXOP after receiving the first PPDU, wherein the second PPDU does not include the L-STF, the L-LTF, the L-SIG field and the RL-SIG field, and the second PPDU is configured based on the small PPDU. to perform TXOP responder.

11. In a wireless local area network (WLAN) system, at least one computer-readable recording medium including instructions based on being executed by at least one processor, A step of transmitting control information regarding a small PPDU (Physical Protocol Data Unit) by a TXOP holder who has acquired a TXOP (transmission opportunity); A step of transmitting a first PPDU by the TXOP holder within the TXOP, wherein the first PPDU includes an L-STF (Legacy Short Training Field), an L-LTF (Legacy Long Training Field), an L-SIG (Legacy Signal) field, an RL-SIG (Repeated L-SIG) field, a U-SIG (Universal Signal) field, an STF (Short Training Field), an LTF (Long Training Field), and a data field, and wherein the first PPDU is configured based on the small PPDU; and A step of transmitting a second PPDU by the TXOP holder within the TXOP after transmitting the first PPDU, wherein the second PPDU does not include the L-STF, the L-LTF, the L-SIG field, and the RL-SIG field, and the second PPDU is configured based on the small PPDU. Performing an operation that includes device.

12. In a wireless local area network (WLAN) system, At least one transceiver; at least one processor; and At least one computer memory operably connectable to said at least one transceiver and said at least one processor, said computer memory storing instructions for performing an operation based on being executed by said at least one processor, The instructions of at least one computer memory are: A step of transmitting control information regarding a small PPDU (Physical Protocol Data Unit) by a TXOP holder who has acquired a TXOP (transmission opportunity); A step of transmitting a first PPDU by the TXOP holder within the TXOP, wherein the first PPDU includes an L-STF (Legacy Short Training Field), an L-LTF (Legacy Long Training Field), an L-SIG (Legacy Signal) field, an RL-SIG (Repeated L-SIG) field, a U-SIG (Universal Signal) field, an STF (Short Training Field), an LTF (Long Training Field), and a data field, and wherein the first PPDU is configured based on the small PPDU; and A step of transmitting a second PPDU by the TXOP holder within the TXOP after transmitting the first PPDU, wherein the second PPDU does not include the L-STF, the L-LTF, the L-SIG field, and the RL-SIG field, and the second PPDU is configured based on the small PPDU. to perform device.

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