Improved Wi-Fi sensing procedure

Abstract

This specification proposes a new signal transmission / reception procedure between STAs when sensing measurement initiated by a STA other than the AP is performed. According to one embodiment of this specification, a sensing measurement procedure is proposed in which a STA other than the AP transmits a sensing start frame to the AP, whereby the AP requests a responder STA to transmit an NDP frame. According to another embodiment of this specification, a method for configuring frames transmitted and received in the procedure is proposed.

Description

【Technical Field】 【0001】 This specification relates to a wireless LAN system, and more particularly, to wireless LAN sensing. 【Background Art】 【0002】 WLAN (wireless local area network) has been improved in various ways. For example, IEEE802.11bf wireless LAN sensing is the first standard in which communication and radar technologies are integrated. Although the demand for unlicensed frequencies has been increasing rapidly in daily life and across industries, there are limitations to the new supply of frequencies. Therefore, the development of integrated technologies for communication and radar is a very favorable direction in terms of increasing frequency utilization efficiency. There have already been developed sensing technologies that use existing wireless LAN signals to detect movements behind walls, and radar technologies that use FMCW (Frequency Modulated Continuous Wave) signals in the 70 GHz band to detect movements inside vehicles. However, it is of great significance in that it can further improve sensing performance in relation to the IEEE802.11bf standardization. In particular, in modern society, the importance of privacy protection is being increasingly emphasized, and different from CCTV, the development of wireless LAN sensing technology, which is more legally free from the problem of privacy infringement, is further expected. 【0003】 On the other hand, the overall radar market is expected to grow to an average annual growth rate of about 5% by 2025 across the board in automobiles, defense, industry, life, etc. In particular, in the case of life sensors, the average annual growth rate is expected to grow rapidly to the level of 70%. Since wireless LAN sensing technology can be applied to a wide range of real-life applications such as motion detection, respiration monitoring, positioning / tracking, fall detection, infant detection in vehicles, appearance / proximity recognition, personal identification, body movement recognition, and behavior recognition, it is expected to contribute to the growth of related new businesses and the improvement of corporate competitiveness. 【0004】 For example, the wireless LAN (WLAN) sensing proposed herein can be used to sense the movement or gestures of an object (person or thing). Specifically, a wireless LAN STA can sense the movement or gestures of an object (person or thing) based on the measurement result for various types of frames / packets designed for wireless LAN sensing. 【0005】 When sensing measurements are performed initiated by an STA that is not an AP, a definition for P2P (peer-to-peer) based signal transmission and reception between STAs may be required. However, according to current wireless LAN standards, P2P based signal transmission and reception is not supported. [Overview of the Initiative] [Means for solving the problem] 【0006】 This specification proposes a new signal transmission and reception procedure between STAs when a sensing measurement initiated by a non-AP STA is performed. According to one embodiment of this specification, a sensing measurement procedure is proposed in which the non-AP STA transmits a sensing initiation frame to the AP, thereby initiating the AP. According to another embodiment of this specification, a procedure is proposed in which the non-AP STA transmits a sensing initiation frame to the AP, thereby initiating the AP to request the responding STA to transmit an NDP frame. According to yet another embodiment of this specification, a method for structuring the frames transmitted and received in the above procedure is proposed. [Effects of the Invention] 【0007】 This specification proposes a novel signal transmission and reception procedure without P2P operation when the sensing procedure is initiated by a non-AP STA. Therefore, the overall complexity of the sensing procedure, including sensing measurements, can be reduced. [Brief explanation of the drawing] 【0008】 [Figure 1]This document presents an example of a wireless LAN sensing scenario using a multiplex sensing transmitter. [Figure 2] This document presents an example of a wireless LAN sensing scenario using a multiplex sensing receiver. [Figure 3] An example of a wireless LAN sensing procedure is shown below. [Figure 4] This is one example of a classification of wireless LAN sensing. [Figure 5] This demonstrates indoor positioning using CSI-based wireless LAN sensing. [Figure 6] This is an example of a wireless LAN sensing device. [Figure 7] This diagram simply illustrates the PPDU structure supported by an 802.11ay wireless LAN system. [Figure 8] An example of a sensing frame format is shown below. [Figure 9] Here are some other examples of sensing frame formats. [Figure 10] Here are some other examples of sensing frame formats. [Figure 11] Here are some other examples of sensing frame formats. [Figure 12] Here are some other examples of sensing frame formats. [Figure 13] Here are some other examples of sensing frame formats. [Figure 14] A modified example of the transmitting and / or receiving device described herein is shown. [Figure 15] This shows an example of a measurement sequence when the initiator, a non-AP STA, acts as the transmitter. [Figure 16] This shows an example of a measurement sequence / order of measurements when the initiator, a non-AP STA, acts as the receiver. [Figure 17] This is a flowchart illustrating an example of a method executed by a starting device in a wireless LAN system. [Figure 18]This is a flowchart illustrating an example of a method performed by an access point (AP) in a wireless LAN system. [Modes for carrying out the invention] 【0009】 In this specification, "A or B" can mean "A only," "B only," or "both A and B." Alternatively, in this specification, "A or B" can be interpreted as "A and / or B." For example, in this specification, "A, B, or C" can mean "A only," "B only," "C only," or "any combination of A, B, and C." 【0010】 In this specification, slashes ( / ) and commas can mean "and / or". For example, "A / B" can mean "A and / or B". Thus, "A / B" can mean "A only", "B only", or "both A and B". For example, "A, B, C" can mean "A, B, or C". 【0011】 In this specification, "at least one of A and B" may mean "A only," "B only," or "both A and B." Furthermore, in this specification, the expressions "at least one of A or B" and "at least one of A and / or B" may be interpreted similarly to "at least one of A and B." 【0012】 Also, in this specification, "at least one of A, B, and C" can mean "only A", "only B", "only C", or "any combination of A, B, and C". Also, "at least one of A, B, or C" and "at least one of A, B, and / or C" can mean "at least one of A, B, and C". 【0013】 In this specification, the technical features separately described within one drawing can be implemented individually or simultaneously. 【0014】 The following example of this specification can be applied to various wireless communication systems. For example, the following example of this specification can be applied to a wireless local area network (WLAN) system. For example, this specification can be applied to the IEEE 802.11ad standard and the IEEE 802.11ay standard. Also, this specification can be applied to newly proposed wireless LAN sensing standards or the IEEE 802.11bf standard. 【0015】 Hereinafter, to describe the technical features of this specification, the technical features to which this specification can be applied will be described. 【0016】 Wireless LAN sensing technology is a type of radar technology that can be implemented even without a standard, but it is believed that more powerful performance can be achieved through standardization. The IEEE 802.11bf standard defines devices participating in wireless LAN sensing by function as shown in the table below. Based on their function, these devices can be classified into devices that initiate wireless LAN sensing, devices that participate, devices that transmit sensing PPDUs (Physical Layer Protocol Data Units), and devices that receive them. 【0017】 [Table 1] 【0018】 Figure 1 shows an example of a wireless LAN sensing scenario using a multiplex sensing transmitter. 【0019】 Figure 2 shows an example of a wireless LAN sensing scenario using a multiplex sensing receiver. 【0020】 Figures 1 and 2 illustrate sensing scenarios based on the function and placement of wireless LAN sensing devices. Assuming one sensing initiator and multiple sensing participants, Figure 1 shows a scenario using multiple sensing PPDU transmitters, and Figure 2 shows a scenario using multiple sensing PPDU receivers. Assuming that the sensing PPDU receivers include a sensing measurement signal processing unit, in the case of Figure 2, an additional procedure is required to transmit (feed back) the sensing measurement results to the sensing initiator (STA5). 【0021】 Figure 3 shows an example of a wireless LAN sensing procedure. 【0022】 The procedure for wireless LAN sensing involves discovery, negotiation, measurement exchange, and tear-down between the wireless LAN sensing initiator and participating devices. Discovery is the process of determining the sensing capabilities of the wireless LAN devices; negotiation is the process of determining sensing parameters between the sensing initiator and participating devices; measurement exchange is the process of transmitting sensing PPDUs and sensing measurement results; and tear-down is the process of ending the sensing procedure. 【0023】 Figure 4 shows an example of a classification of wireless LAN sensing. 【0024】 Wireless LAN sensing can be classified into CSI-based sensing, which utilizes channel state information of signals that have traveled from the transmitter through the channel to the receiver, and radar-based sensing, which utilizes signals that have been received after the transmitted signal has been reflected by an object. Furthermore, each sensing technology can be divided into two types: one in which the sensing transmitter directly participates in the sensing process (coordinated CSI, active radar), and another in which the sensing transmitter does not participate in the sensing process, i.e., there is no dedicated transmitter that participates in the sensing process (un-coordinated CSI, passive radar). 【0025】 Figure 5 shows indoor positioning using CSI-based wireless LAN sensing. 【0026】 Figure 5 shows how CSI-based wireless LAN sensing can be used for indoor positioning. By using CSI to determine the angle of arrival and time of arrival, and then converting these to orthogonal coordinates, indoor positioning information can be obtained. 【0027】 Figure 6 shows an example of a wireless LAN sensing device. 【0028】 Figure 6 shows a wireless LAN sensing device implemented using the MATLAB® toolbox, Zynq, and USRP. The MATLAB toolbox generates an IEEE 802.11ax wireless LAN signal, and the Zynq SDR (Software Defined Radio) generates an RF signal. The signal passing through the channel is received by the USRP SDR, and sensing signal processing is performed in the MATLAB toolbox. Here, one reference channel (a channel that can be received directly from the sensing transmitter) and one surveillance channel (a channel that can be received after being reflected by an object) were assumed. Analysis using the wireless LAN sensing device yielded unique characteristics that allowed for the distinction of motion and body movements. 【0029】 Currently, the IEEE 802.11bf wireless LAN sensing standardization is in its initial development stage, and cooperative sensing technology to improve sensing accuracy will be a key focus going forward. Synchronization technology for sensing signals, CSI management and utilization technology, sensing parameter negotiation and sharing technology, and scheduling technology for CSI generation are expected to be core standardization topics. Other topics to be considered include long-range sensing technology, low-power sensing technology, sensing security, and privacy protection technology. 【0030】 IEEE 802.11bf wireless LAN sensing is a type of radar technology that utilizes common wireless LAN signals anytime, anywhere. The table below shows typical IEEE 802.11bf use cases, which can be applied to a wide range of real-world applications, including indoor detection, motion recognition, health management, 3D vision, and vehicle detection. Since it is mainly used indoors, the operating range is approximately 10 to 20 meters, and the distance accuracy does not exceed a maximum of 2 meters. 【0031】 [Table 2-1] 【0032】 [Table 2-2] 【0033】 [Table 2-3] 【0034】 [Table 2-4] 【0035】 IEEE 802.11 is discussing technologies for sensing the movement and gestures of objects (people or things) using Wi-Fi signals across various bands. For example, it is possible to sense the movement and gestures of objects using 60GHz band Wi-Fi signals (e.g., 802.11ad or 802.11ay signals). It is also possible to sense the movement and gestures of objects using sub-7GHz band Wi-Fi signals (e.g., 802.11ac, 802.11ax, 802.11be signals). 【0036】 The following describes the technical characteristics of PPDU, which is based on the 802.11ay standard and is one of the 60GHz band Wi-Fi signals that can be used for wireless LAN sensing. 【0037】 Figure 7 is a simplified diagram illustrating the PPDU structure supported by an 802.11ay wireless LAN system. 【0038】 As shown in Figure 7, a PPDU format applicable to an 802.11ay system may include L-STF, L-CEF, L-Header, EDMG-Header-A, EDMG-STF, EDMG-CEF, EDMG-Header-B, Data, and TRN fields, the fields of which may be selectively included depending on the form of the PPDU (e.g., SU PPDU, MU PPDU, etc.). 【0039】 Here, the portion containing the L-STF, L-CEF, and L-Header fields can be named the Non-EDMG portion, and the remaining portion can be named the EDMG portion. Additionally, the L-STF, L-CEF, L-Header, and EDMG-Header-A fields can be named the pre-EDMG modulated fields, and the remaining portion can be named the EDMG modulated fields. 【0040】 The EDMG-Header-A field contains the information required to demodulate the EDMG PPDU. The definition of the EDMG-Header-A field is the same as that for the EDMG SC mode PPDU and the EDMG OFDM mode PPDU, but different from that for the EDMG control mode PPDU. 【0041】 The structure of EDMG-STF is determined by the number of consecutive 2.16GHz channels on which the EDMG PPDU is transmitted and i STS Index i of the nth space-time stream STS It depends on the following: For a single space-time stream EDMG PPDU transmission using EDMG SC mode over a single 2.16 GHz channel, the EDMG-STF field does not exist. For EDMG SC transmission, the EDMG-STF field must be modulated using pi / (2-BPSK). 【0042】 The structure of EDMG-CEF is determined by the number of consecutive 2.16 GHz channels on which the EDMG PPDU is transmitted and the space-time stream iSTS It depends on the number of elements. For a single space-time stream EDMG PPDU transmission using EDMG SC mode over a single 2.16 GHz channel, the EDMG-CEF field does not exist. For EDMG SC transmission, the EDMG-CEF field must be modulated using pi / (2-BPSK). 【0043】 The (legacy) preamble portion of the PPDU described above can be used for packet detection, automatic gain control (AGC), frequency offset estimation, synchronization, modulation (SC or OFDM) instruction, and channel estimation. The preamble format can be common to OFDM and SC packets. In this case, the preamble can consist of a Short Training Field (STF) and a Channel Estimation (CE) field located after the STF field. 【0044】 The following describes an example of a sensing frame format proposed for sensing or wireless LAN (WLAN) sensing in the 60 GHz band. The frames, packets, and / or data units used for sensing or wireless LAN (WLAN) sensing proposed herein can be called sensing frames. The sensing frames can be referred to by various names such as sensing measurement frame, sensing operation frame, and / or measurement frame. 【0045】 Figure 8 shows an example of a sensing frame format. 【0046】 Wi-Fi sensing signals can be transmitted and received between AP / STA and STA for channel estimation using 60GHz Wi-Fi signals. In this case, to support backward compatibility with existing 60GHz Wi-Fi signals, 802.11ad and 802.11ay, the sensing frame can be composed in a frame format as shown in Figure 8, including a non-EDMG preamble portion (i.e., L-STF, L-CEF, L-Header). 【0047】 As shown in Figure 8, the sensing frame can consist of L-STF, L-CEF, L-Header, EDMG-Header A, EDMG-STF, and EDMG-CEF. 【0048】 In other words, the sensing frame can be configured without a data field, unlike existing EDMG frames, because it estimates channel changes between P2P (Point to Point) or P2MP (Point to Multipoint) to perform sensing on an STA or object. 【0049】 Since the EDMG frame can be transmitted using one or more channels in the 60 GHz band (i.e., diverse channel bandwidths), the sensing frame is composed of the EDMG-STF and EDMG-CEF fields, as shown in Figure 8. 【0050】 By utilizing the EDMG-STF and EDMG-CEF fields, the STA / AP can accurately measure channel information using the sensing transmit / receive bandwidth. 【0051】 Information regarding the BW used for sensing can be transmitted via EDMG-header A, and at this time, a variety of BWs can be used for transmission, as described below. 【0052】 [Table 3] 【0053】 Figure 9 shows another example of a sensing frame format. 【0054】 Unlike the above, the sensing signal can be transmitted using only a fixed bandwidth (e.g., 2.16 GHz), and in such cases, additional AGC is not required, and the EDMG-STF can be omitted. Therefore, when sensing is performed using only a predetermined bandwidth, the EDMG-STF can be omitted, and the sensing frame format can be configured as shown in Figure 9. Also, because only a predetermined bandwidth is used, the EDMG-header does not include the bandwidth field during sensing, unlike existing versions. 【0055】 Figure 10 shows another example of a sensing frame format. 【0056】 802.11ay transmission at 60 GHz essentially uses beamforming to transmit signals, and in this process, a training (i.e., TRN) field is used to set the AWV (antenna weight vector) for the Tx antenna and Rx antenna in order to set the optimal beam between Tx and Rx. Therefore, the sensing frame transmits signals using a previously determined AWV, making it difficult to accurately reflect changed channel conditions. Accordingly, in order to more accurately measure changes to the channel, the sensing frame can be configured to include a TRN field as follows, in which case information about the channel can be measured via the TRN field. 【0057】 In Figure 10, the sensing frame does not include a data field, and channel measurement for sensing is performed using TRN; therefore, the EDMG-CEF field for channel estimation mentioned above can be omitted. Accordingly, the sensing frame format can be configured as shown in Figure 11. 【0058】 Figure 11 shows another example of a sensing frame format. 【0059】 The following describes the technical characteristics of PPDU using sub-7GHz Wi-Fi signals, which can be utilized for wireless LAN sensing. 【0060】 The following describes an example of a sensing frame format proposed for sensing in the sub-7GHz band or for wireless LAN (WLAN) sensing. For example, for sensing according to this specification, various PPDUs in the 2.4GHz, 5GHz, and 6GHz bands can be used as the sensing frame. For example, PPDUs conforming to the IEEE 802.11ac, 802.11ax, and / or 802.11be standards can be used as the sensing frame. 【0061】 Figure 12 shows another example of a sensing frame format. 【0062】 The sensing frame according to this specification may use only some of the fields shown in Figure 12. For example, the Data field shown in Figure 12 may be omitted. Additionally or alternatively, the VHT-SIG B and / or HE-SIG B fields shown in Figure 12 may be omitted. 【0063】 Figure 13 shows another example of a sensing frame format. 【0064】 The sensing frame described herein may use only a portion of the fields of the EHT (Extreme High Throughput) PPDU shown in Figure 13. For example, the Data field shown in Figure 13 may be omitted. 【0065】 The PPDU in Figure 13 can represent some or all of the PPDU types used in an EHT system. For example, the example in Figure 13 can be used for both SU (single-user) mode and MU (multi-user) mode. In other words, the PPDU in Figure 13 is a PPDU for one receiving STA or multiple receiving STAs. When the PPDU in Figure 13 is used for TB (Trigger-based) mode, the EHT-SIG in Figure 13 can be omitted. In other words, an STA that has received a Trigger frame for UL-MU (Uplink-MU) communication can transmit a PPDU with the EHT-SIG omitted in the example in Figure 13. 【0066】 In Figure 13, the subcarrier spacing for the L-STF, L-LTF, L-SIG, RL-SIG, U-SIG, and EHT-SIG fields is set to 312.5 kHz, while the subcarrier spacing for the EHT-STF, EHT-LTF, and Data fields is set to 78.125 kHz. That is, the tone index (or subcarrier index) for the L-STF, L-LTF, L-SIG, RL-SIG, U-SIG, and EHT-SIG fields can be displayed in units of 312.5 kHz, and the tone index (or subcarrier index) for the EHT-STF, EHT-LTF, and Data fields can be displayed in units of 78.125 kHz. 【0067】 In the PPDU shown in Figure 13, L-LTF and L-STF are the same as in the conventional field. 【0068】 The L-SIG field in Figure 13 can contain, for example, 24 bits of bit information. For example, the 24 bits of information can 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 can contain information about the length or time duration of the PPDU. For example, the value of the 12-bit Length field can be determined based on the type of PPDU. For example, if the PPDU is a non-HT, HT, VHT PPDU, or EHT PPDU, the value of the Length field can be determined to be a multiple of 3. For example, if the PPDU is an HE PPDU, the value of the Length field can be determined to be a multiple of 3 + 1 or a multiple of 3 + 2. In other words, for non-HT, HT, VHT PPDU, or EHT PPDU, the value of the Length field can be determined to be a multiple of 3, and for HE PPDU, the value of the Length field can be determined to be a multiple of 3 + 1 or a multiple of 3 + 2. 【0069】 The transmitting STA can generate an RL-SIG, which is generated in the same way as the L-SIG. BPSK modulation can be applied to the RL-SIG. Based on the presence of the RL-SIG, the receiving STA can know that the received PPDU is either an HE PPDU or an EHT PPDU. 【0070】 A U-SIG (Universal SIG) can be inserted after the RL-SIG in Figure 13. The U-SIG can be referred to by various names such as the first SIG field, first SIG, first type SIG, control signal, control signal field, or first (type) control signal. 【0071】 A U-SIG can contain N bits of information and may include information to identify the type of EHT PPDU. For example, a U-SIG can be composed of two symbols (e.g., two consecutive OFDM symbols). Each symbol for the U-SIG (e.g., an OFDM symbol) may have a duration of 4us. Each symbol of the U-SIG can be used to transmit 26 bits of information. For example, each symbol of the U-SIG can be transmitted and received based on 52 data tones and 4 pilot tones. 【0072】 U-SIGs can be configured in 20MHz units. For example, if an 80MHz PPDU is configured, U-SIGs can be duplicated; that is, four identical U-SIGs can be contained within an 80MHz PPDU. PPDUs exceeding an 80MHz bandwidth can contain different U-SIGs from each other. 【0073】 The EHT-SIG in Figure 13 may include control information for the receiving STA. For example, the EHT-SIG may include a common field and a user-specific field. The common field may be omitted, and the number of user-specific fields may be determined based on the number of users. The common field may include RU allocation information. The RU allocation information may mean information about the location of RUs to which multiple users (i.e., multiple receiving STAs) are assigned. The RU allocation information may consist of 9-bit units. The user-specific field may include information for decoding at least one RU identified via the common field (e.g., STA ID information assigned to the RU, MCS index applied to the RU, LDPC / BCC coding type information applied to the RU, etc.). 【0074】 The EHT-STF in Figure 13 can be used to improve automatic gain control estimation in MIMO (multiple input multiple output) or OFDMA environments. The EHT-LTF in Figure 13 can be used to estimate channels in MIMO or OFDMA environments. 【0075】 Figure 14 shows a modified example of the transmitting and / or receiving apparatus described herein. 【0076】 The device shown in Figure 14 can also be referred to by various names such as mobile terminal, wireless device, Wireless Transmit / Receive Unit (WTRU), User Equipment (UE), Mobile Station (MS), Mobile Subscriber Unit, or simply user. Furthermore, the device in Figure 14 can also be referred to by various names such as Base Station, Node-B, Access Point (AP), Repeater, Router, and Relay. 【0077】 The processor 610 in Figure 14 can direct and control operations performed in STA, transmit STA, receive STA, AP, non-AP, and / or user-STA as specified herein. For example, the processor 610 can receive signals via the transceiver 630, process received signals, generate transmit signals, and perform control for signal transmission. The illustrated processor, memory, and transceiver may each be embodied on separate chips, or at least two or more blocks / functions may be embodied on a single chip. 【0078】 The memory 620 in Figure 14 can store signals received via the transceiver 630 (i.e., received signals) and signals transmitted via the transceiver 630 (i.e., transmitted signals). 【0079】 Referring to Figure 14, the power management module 611 manages power to the processor 610 and / or transceiver 630. The battery 612 supplies power to the power management module 611. The display 613 outputs the results processed by the processor 610. The keypad 614 receives inputs used by the processor 610. The keypad 614 can be displayed on the display 613. The SIM card 615 is an integrated circuit used to securely store the IMSI (international mobile subscriber identity) and associated keys used to identify and authenticate subscribers in mobile phone devices such as mobile phones and computers. 【0080】 Referring to Figure 14, speaker 640 can output sound-related results processed by processor 610. Microphone 641 can receive sound-related inputs used by processor 610. 【0081】 The method proposed in this specification is described below. 【0082】 To improve the accuracy and resolution of WLAN sensing, WLAN sensing that utilizes signal transmission and reception channels between multiple sensing STAs is considered. The sensing STAs may include STAs and APs. Therefore, channel estimation for each transmission and reception channel may be required in order to efficiently perform WLAN sensing using signal transmission and reception channels between a sensing initiator / initiator and multiple sensing responders / responders. This specification proposes a channel sounding method for efficiently performing channel measurement for multiple transmission and reception channels used for sensing. 【0083】 During WLAN sensing, the initiator can measure the channel using transmit and receive channels with multiple responders. In this case, the initiator can perform the sensing operation with the following roles: 【0084】 1. Initiator & Transmitter: This can mean a case where the initiator acts as a transmitter, sending a measurement frame for channel estimation to the sensing responder. 【0085】 2. Initiator and receiver: This can mean a case where the initiator requests the responder to transmit a measurement frame for channel estimation and then receives the said measurement frame. 【0086】 As defined above, the sensing initiator is either an AP or a non-AP STA. This specification proposes a sensing measurement procedure when the sensing initiator is a non-AP STA. 【0087】 As an example, the initiator, a non-AP STA, can act as the transmitter. Figure 15 shows an example of a measurement sequence when the initiator, a non-AP STA, acts as the transmitter. 【0088】 Referring to Figure 15, the initiator performing the transmitter role can send a sensing request frame to responder 1 (AP). Here, the initiator is a non-AP STA. Responder 1 can send a response frame to the initiator in response to the sensing request frame. 【0089】 Thereafter, responder 1 can transmit a sensing pole frame. Responder n can then transmit a response frame to responder 1 for the sensing pole frame. 【0090】 Thereafter, responder 1 can transmit a trigger frame. The initiator can transmit an NDP frame based on the trigger frame. The transmission of the NDP frame is an action triggered by the trigger frame. 【0091】 Thereafter, responder 1 may send a feedback request frame to responder n. In response to the feedback request frame, responder n may send a feedback frame to responder 1. Responder 1 may send a sensing feedback frame to the initiator. 【0092】 In another embodiment, after receiving a feedback request frame from the initiator, the responder 1 may send a sensing feedback frame to the initiator. 【0093】 As shown in Figure 15, when the initiator, a non-AP STA, performs the role of the transmitter, some or all of the following rules may apply. 【0094】 1. STAs / APs participating in sensing can exchange information regarding sensing roles and information for the STAs through negotiations for sensing operations. 【0095】 2. The initiating non-AP STA can send a sensing request frame or an initial sensing request frame to the APs participating in the sensing in order to start sensing measurements. 【0096】 2.A. The request frame transmitted by the non-AP STA may include some or all of the following information: 【0097】 2. Information for AI Sensing Responders (STAs) 【0098】 2.Ai1. The above information is STA-ID (identifier) ​​information for STAs participating in sensing, obtained through negotiation or discovery procedures. 【0099】 2.A.ii. Sensing role indication 【0100】 2.A.ii.1. The above instructions are information regarding whether the initiator will perform the role of transmitter or receiver. 【0101】 2.A.ii.2. The instruction may consist of 1 bit. For example, if the initiator is performing the role of transmitter, the instruction may be set to 0, and if the initiator is performing the role of receiver, the instruction may be set to 1. 【0102】 2.A.iii. Information regarding TXOP or sensing duration 【0103】 2.A.iii.1. The information above is information regarding the time required to exchange the sensing measurement frame. 【0104】 2.A.iii.2. Based on the above information, a third-party STA can perform network allocation vector (NAV) configuration. Therefore, sensing operations can be protected. 【0105】 2.A.iii.3. The aforementioned TXOP is either a TXOP requested by a non-AP STA from an AP for sensing purposes, or a TXOP determined during sensing negotiations. 【0106】 2.A.iii.3.A. If the TXOP is determined during negotiations, the information may be shared with all STAs participating in sensing. Furthermore, all STAs participating in sensing may use the information for sensing operations. 【0107】 2.A.iii.4. The above information can be composed of 7 bits. 【0108】 2.A.iv. Information regarding Sensing burst configuration 【0109】 2.A.iv.1. The sensing period may consist of a number of sensing bursts. In this case, the information may include information on the number and magnitude of the bursts. 【0110】 2. Av Sensing Operation Bandwidth Information (Sensing operation BW info) 【0111】 2. Av1. The information is information regarding the bandwidth in which the sensing measurement is performed. Here, the information can consist of 3 bits to indicate 20, 40, 80, 160 and / or 320 MHz. 【0112】 2.B.AP can send a response frame to the non-AP STA in response to the request frame sent by the non-AP STA. In this case, the response frame may include the following information: 【0113】 2. Bi Sensing Bandwidth (Sensing BW) 【0114】 2.B.ii. TXOP for sensing 【0115】 2.B.iii. Sensing confirmation 【0116】 2.C. Through the sensing request frames and response frames exchanged between the non-AP STA and the AP, the third-party STA does not perform channel access while the NAV is set up and sensing operations are being performed. 【0117】 3. An AP that has sent a sensing responder / response frame to the initiator may send a sensing pole frame or sensing trigger frame to a sensing STA that has sensing capability as determined via the negotiation / sensing request frame, in order to determine whether it can perform sensing. 【0118】 3.A. The sensing pole frame or sensing trigger frame may include one or more of the following information: 【0119】 3. AiSTA-ID: ID for Sensing STA 【0120】 3.A.ii. Spatial stream (SS) allocation sensing: Information about the spatial stream allocated to the STA during sensing. 【0121】 3.A.iii.BW: Sensing bandwidth 【0122】 3.A.iv. Sensing Measurement Indication 【0123】 3. AV Sensing Channel Confirmation Request 【0124】 3. Av1. The information in response to the sensing channel confirmation request may indicate whether transmission and reception are possible with respect to the sensing bandwidth. The information may be structured in 20 MHz units. The information may also be structured as a bitmap. 【0125】 3. A.vi. Whether or not a Sensing Feedback Request is Possible 【0126】 3.A.vi.1. The information regarding the request for sensing feedback indicates whether or not it is necessary to send measurement feedback. 【0127】 3.A.vii. Assignment information for response frames 【0128】 3.A.vii.1. The information may include RU allocation information for sending response frames. 【0129】 4. As described above, a sensing responder STA that receives a sensing poll / polling frame from an AP can send a response frame to the AP. 【0130】 4.A. The response frames may be transmitted sequentially to the AP during the SIFS interval. Alternatively, the response frames may be transmitted after the SIFS interval, after receiving the request frame, using the bandwidth or resource unit allocation (RU) allocated by the AP. 【0131】 5. Through the response frame, the AP can identify the STAs that will participate in the actual sensing measurement. After receiving the response frame and after the SIFS has elapsed, the AP may send a trigger frame to perform the sensing measurement. 【0132】 5.A. In the above, the trigger frame transmitted by the AP can be used to request the Non-AP STA, which is the initiator, to transmit an NDP (null data packet) frame. 【0133】 5. The trigger frame transmitted by the Ai AP may include the following information: 【0134】 5. Ai1. ID of the initiator (non-AP STA) 【0135】 5. Ai2.RU allocation or allocated subchannel information (allocated subchannel info) 【0136】 5. Ai3. Information regarding the number of spatial streams 【0137】 5. Ai4. Number of LTFs (long training fields) or the number of LTF repetitions. 【0138】 5. Ai5.LTF size 【0139】 5. Ai6. Sensing measurement indication or NDP transmission indication 【0140】 5.Ai6.A. The above information is a request for the initiator to send an NDP frame. 【0141】 5.Ai6.B. The responder can understand that the transmission of NDP frames has begun via the aforementioned information. 【0142】 5.B. The trigger frame can also be used to inform the sensing responder that the transmission of an NDP frame has begun. 【0143】 6. The initiator who receives the trigger frame for transmitting the NDP frame from the AP may transmit the NDP frame for sensing measurement. The NDP frame may be transmitted after the trigger frame has been received and after the SIFS has elapsed. 【0144】 7. After the initiator has sent the NDP frame, the AP may send a feedback request frame to the responder STA for channel measurement feedback. 【0145】 7.A. The feedback request frame may be sent after the NDP frame has been sent and after SIFS has elapsed. 【0146】 7.B. The feedback request frame may include some or all of the following information: 【0147】 7. Bi-feedback type 【0148】 7.Bi1. The feedback type may include CQI (channel quality indicator), RSSI (Received Signal Strength Indicator), angle, compressed, etc. 【0149】 7.B.ii. Codebook size 【0150】 7.B.ii.1. The aforementioned information is information regarding the magnitude of the information being fed back. 【0151】 7.B.iii. Feedback resolution 【0152】 7.B.iii.1. The above information is a channel measurement unit (e.g., n g It can include information for (e.g., 1, 2, 4, 8, 16). 【0153】 7.B.iv.RU allocation 【0154】 7.B.iv.1. The information may include information for RUs used when performing feedback of measurement information. 【0155】 7. Bv Spatial Stream (SS) 【0156】 7.Bv1. The above information may include information regarding the number of assigned SSs and the starting point of the assigned SSs. 【0157】 7.B.vi.MCS(modulation and coding scheme) 【0158】 7.B.vi.1. The aforementioned information may include MCS information used for feedback information. 【0159】 7.B.vii. Encoding 【0160】 7.B.vii.1. The aforementioned information may provide encoding information (BCC or LDPC) for the feedback information. 【0161】 8. After transmitting the feedback request frame, the AP that receives feedback information from the responder STA can transmit channel measurement information received from other responders to the initiator. 【0162】 8.A. After receiving the feedback request frame, the responder STA may simultaneously transmit feedback information using the RU assigned after the SIFS has elapsed. 【0163】 8.B. In contrast to the above, the responder may sequentially send feedback information to the AP at SIFS intervals. 【0164】 8.C. After receiving feedback information from all responders (STA) that participated in sensing, and after the SIFS has elapsed, the AP can send all the feedback information to the initiator. 【0165】 8.D. In contrast to the foregoing, AP may send all feedback information to the initiator after receiving a feedback request frame from the initiator. 【0166】 9. While the above assumes that the sensing measurement procedure is performed on a single TXOP, the measurement can also be performed on multiple TXOPs. 【0167】 9.A. As an example, a TXOP for sensing feedback can be configured separately. 【0168】 9.B. As another example, TXOPs can be independently configured for each of the following: sensing request and response, sensing polling and NDP transmission, and feedback procedure. 【0169】 Unlike the above, the initiator, non-AP STA, can also act as the receiver. Figure 16 shows an example of a measurement sequence when the initiator, non-AP STA, performs the role of the receiver. 【0170】 If the initiator, a non-AP STA, is performing the role of the receiver, some or all of the following rules may apply: 【0171】 10. The same sensing procedures described in Rules 1 to 4 above can be applied. For example, referring to Figure 16, an initiator, which is a non-AP STA, can send a sensing request frame to responder_1, which is an AP. In this case, the AP that receives the request frame can send a response frame to the initiator after the SIFS has elapsed. 【0172】 10.A. The request frame and response frame may include the information proposed in Rules 1 and 2 above. 【0173】 11. The AP may transmit a sensing poll / polling frame after transmitting a response frame. In this case, each frame may be constructed as described in rules 3 and 4 above. Frame exchange may also be performed between the AP and the responder STA. 【0174】 12. As shown in Figure 16, an AP that has identified an actual sensing responder participating in sensing via a response frame received from a responder STA can send a trigger frame to the responder STA to request the responder STA to send an NDP frame. 【0175】 12.A. The trigger frame for requesting the transmission of the NDP frame may include the following information: 【0176】 12. AiNDP Transmission Request Indication 【0177】 12.A.ii. Information regarding the Responder STA's ID 【0178】 12.A.ii.1. The above information may include ID information for the STA that transmits the NDP frame. 【0179】 12.A.iii.LTF Information 【0180】 12.A.iii.1. The above information may indicate the size or type of the LTF (e.g., 1x, 2x, 4x). 【0181】 12.A.iii.2. The above information may include information regarding the repetition of LTF. 【0182】 12.A.iii.3. The above information can indicate the number of LTF symbols. 【0183】 12.A.iv. Number of spatial streams (Nss) 【0184】 12.A.iv.1. The above information can indicate the Nss allocated per STA. 【0185】 12.A.iv.2. The above information can inform the total Nss. 【0186】 12. RU / subchannel allocation for Av bandwidth or NDP frames 【0187】 12.Av1. The above information may include information regarding the bandwidth and RU / subchannel for transmitting the NDP frame. 【0188】 13. After receiving the trigger frame requesting the transmission of the NDP frame, and after the SIFS has elapsed, the responder STA may transmit the NDP frame to the initiator. 【0189】 13.A. Here, the AP can also send an NDP frame to the initiator. 【0190】 13.B. The NDP frames may be transmitted simultaneously. Alternatively, the NDP frames may be transmitted sequentially by the responder STA at SIFS intervals. 【0191】 The following describes examples of sensing procedures performed in a wireless LAN system, as partially embodied in this specification. Figure 17 is a flowchart of an example of a method performed by an initiator in a wireless LAN system. 【0192】 Referring to Figure 17, the initiating device transmits a sensing initiation frame to the AP (S1710). Here, the initiating device is an STA (non-AP station) that is not an AP. The sensing initiation frame is the same as the sensing request frame in Figures 15 and / or 16. In response to the sensing initiation frame, the initiating device receives a sensing response frame from the AP (S1720). 【0193】 Thereafter, the starter device performs one of the following: a transmitter operation or a receiver operation, based on its sensing role (S1730). When the starter device performs the transmitter role, the procedure described with reference to Figure 15 can be performed. Specifically, based on the starter device performing the transmitter role, the starter device can transmit a first NDP frame. Here, the first NDP frame is a frame transmitted by the starter device based on a trigger frame received from the AP. 【0194】 Furthermore, if the initiator is performing the receiver role, the procedure described with reference to Figure 16 can be performed. For example, based on the initiator performing the receiver role, the initiator can receive a second NDP frame from one or more responders. 【0195】 Figure 18 is a flowchart illustrating an example of a method performed by an access point (AP) in a wireless LAN system. 【0196】 Referring to Figure 18, the AP receives a sensing start frame from the starter (S1810). Here, the starter is a non-AP STA. The AP transmits a sensing response frame to the starter in response to the start frame (S1820). 【0197】 The AP transmits a sensing pole frame (S1830). The AP receives sensing pole response frames from one or more response devices as a response to the sensing pole frame (S1840). 【0198】 The AP transmits a trigger frame to the starter and one of the one or more responseers based on the role of the starter (S1850). The role of the starter is either a transmitter or a receiver. 【0199】 An example where the role of the initiator is that of a transmitter is the same as the example in Figure 15. Specifically, based on the initiator performing the role of a transmitter, the AP can transmit the trigger frame to the initiator. Here, the trigger frame is a frame that triggers the initiator to transmit an NDP frame. The AP can also transmit a feedback request frame to one or more responders. The AP can also receive a feedback response frame from one or more responders as a response to the feedback request frame. Here, the feedback response frame may include sensing measurement information for sensing measurements performed by one or more responders. The AP can also transmit a feedback frame containing the sensing measurement information to the initiator based on the feedback response frame. 【0200】 Alternatively, an example in which the initiator acts as a receiver is the same as the example in Figure 16. Specifically, based on the initiator acting as a receiver, the AP can transmit the trigger frame to one or more responders. Here, the trigger frame is a frame that triggers the transmission of an NDP frame by one or more responders. In this case, the NDP frame is a frame transmitted to the initiator. The initiator can perform sensing measurements based on the NDP frame. 【0201】 It is obvious that the configuration / proposed method described through Figures 15 and 16 can be applied to Figures 17 and / or 18. Therefore, redundant explanations are omitted. 【0202】 The technical features described herein, as outlined above, are applicable to a variety of applications and business models. For example, these technical features can be applied to wireless communication in devices that support artificial intelligence (AI). 【0203】 Artificial intelligence refers to the field of study that researches artificial intelligence or methodologies that can create it, while machine learning refers to the field of study that researches methodologies for solving various problems dealt with in the field of artificial intelligence. Machine learning can also be defined as an algorithm that improves its performance for any task through continuous experience. 【0204】 An artificial neural network (ANN) is a model used in machine learning that can be broadly defined as a problem-solving model composed of artificial neurons (nodes) that form a network through synaptic connections. An ANN can be defined by the connection patterns between neurons in other layers, the learning process that updates the model parameters, and the activation function that generates the output values. 【0205】 An artificial neural network may comprise an input layer, an output layer, and optionally one or more hidden layers. Each layer may contain one or more neurons, and the artificial neural network may include synapses connecting neurons. In an artificial neural network, each neuron can output an input signal, a weighted value, and a function value of the activation function for the bias received via the synapse. 【0206】 Model parameters refer to parameters determined through learning, including synaptic connection weights and neuron bias. Hyperparameters, on the other hand, refer to parameters that must be set before training in a machine learning algorithm, including the learning rate, iteration count, mini-batch size, and initialization function. 【0207】 The objective of learning an artificial neural network can be considered as determining the model parameters that minimize the loss function. The loss function can be used as an indicator to determine the optimal model parameters during the learning process of the artificial neural network. 【0208】 Machine learning can be classified into supervised learning, unsupervised learning, and reinforcement learning based on the learning method. 【0209】 Supervised learning refers to a method of training an artificial neural network (AI) with labels provided for the training data. A label can be defined as the correct answer (or result value) that the AI ​​should infer when the training data is input to the AI. Unsupervised learning can be defined as a method of training an AI without labels provided for the training data. Reinforcement learning can be defined as a learning method in which an AI is trained to select the action or sequence of actions that maximizes cumulative compensation in each state within a defined environment. 【0210】 Deep learning is sometimes referred to as "deep learning" when it is implemented using a deep neural network (DNN) that has multiple hidden layers within an artificial neural network. Deep learning is a part of machine learning. In the following, machine learning will be used to include deep learning. 【0211】 Furthermore, the technical features described above can be applied to wireless communication for robots. 【0212】 A robot can be defined as a machine that automatically processes or operates on assigned tasks using its own capabilities. In particular, a robot that has the ability to perceive its environment and make decisions and act accordingly can be called an intelligent robot. 【0213】 Robots can be classified into industrial, medical, household, military, etc., depending on their intended use and field. Robots are equipped with a drive unit containing actuators or motors, which allows them to perform various physical actions, such as moving robotic joints. Mobile robots also include wheels, brakes, propellers, etc., in their drive unit, and can travel on the ground or fly in the air via this drive unit. 【0214】 Furthermore, the technical features described above can be applied to devices that support augmented reality. 【0215】 Augmented reality is a general term encompassing virtual reality (VR), augmented reality (AR), and mixed reality (MR). VR technology provides real-world objects and backgrounds only as computer graphics (CG) images, AR technology provides virtually created CG images alongside images of real objects, and MR technology is a computer graphics technology that blends and combines virtual objects with the real world. 【0216】 Mixed Reality (MR) technology is similar to augmented reality (AR) technology in that it displays both real and virtual objects together. However, while AR technology uses virtual objects to complement real objects, MR technology uses virtual and real objects with equal importance. 【0217】 XR technology can be applied to HMDs (Head-Mount Displays), HUDs (Head-Up Displays), mobile phones, tablet PCs, laptops, desktops, TVs, digital signage, and other devices, and devices to which XR technology is applied can be called XR devices.

Claims

[Claim 1] In a method implemented in a WLAN (Wireless Local Area Network) system, The first non-access point (AP) STA (station) transmits a sensing request frame to the access point (AP), The sensing request frame enables the first non-AP STA to invoke a procedure to request the AP to perform a sensing procedure. The sensing request frame includes information related to the sensing responder, The sensing request frame includes sensing role information indicating that the sensing responder will operate as a sensing transmitter or a sensing receiver. The aforementioned sensing responder is non-AP STA, in stages, The first non-AP STA receives a sensing response frame from the AP as a response to the sensing request frame, The first non-AP STA includes the step of receiving a sensing report frame from the AP, The method wherein the sensing report frame includes a sensing measurement report received by the AP. [Claim 2] In a WLAN (Wireless Local Area Network) system, in the first non-access point (AP) STA (station), Memory and The system comprises a processor operably connected to the aforementioned memory, The aforementioned processor is adapted to send a sensing request frame to the AP (access point), The sensing request frame enables the first non-AP STA to invoke a procedure to request the AP to perform a sensing procedure. The sensing request frame includes information related to the sensing responder, The sensing request frame includes sensing role information indicating that the sensing responder will operate as a sensing transmitter or a sensing receiver. The aforementioned sensing responder is a non-AP STA. The aforementioned processor, In response to the sensing request frame, the AP receives a sensing response frame. Further adapted to receive sensing report frames from the aforementioned AP, The sensing report frame includes a first non-AP STA, which contains a sensing measurement report received by the AP. [Claim 3] In a method implemented in a WLAN (Wireless Local Area Network) system, At the stage when the access point (AP) receives a sensing request frame from the first non-AP station (STA), The sensing request frame enables the first non-AP STA to invoke a procedure to request the AP to perform a sensing procedure. The sensing request frame includes information related to the sensing responder, The sensing request frame includes sensing role information indicating that the sensing responder will operate as a sensing transmitter or a sensing receiver. The aforementioned sensing responder is non-AP STA, in stages, The AP transmits a sensing response frame to the first non-AP STA as a response to the sensing request frame, A method comprising the steps of: the AP transmitting a sensing report frame to the first non-AP STA, wherein the sensing report frame includes a sensing measurement report received by the AP. [Claim 4] In an access point (AP) in a WLAN (Wireless Local Area Network) system, Memory and The system comprises a processor operably connected to the aforementioned memory, The processor is adapted to receive a sensing request frame from the first non-AP STA (station), The sensing request frame enables the first non-AP STA to invoke a procedure to request the AP to perform a sensing procedure. The sensing request frame includes information related to the sensing responder, The sensing request frame includes sensing role information indicating that the sensing responder will operate as a sensing transmitter or a sensing receiver. The aforementioned sensing responder is a non-AP STA. The aforementioned processor, As a response to the sensing request frame, a sensing response frame is sent to the first non-AP STA. Further adapted to transmit a sensing report frame to the first non-AP STA, The sensing report frame includes the sensing measurement report received by the AP.

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