Access point and communication method

Abstract

This access point comprises: a control circuit for determining, on the basis of measurement information about a terminal, a parameter pertaining to transmission power of another access point for performing cooperative communication; and a communication circuit for transmitting a control signal including the parameter to the other access point.

Description

Access point and communication method

[0001] The present disclosure relates to an access point and a communication method.

[0002] The Institute of Electrical and Electronics Engineers (IEEE) 802.11 standard, IEEE 802.11bn (hereinafter referred to as "11bn"), is being developed by a study group (SG) as a successor to IEEE 802.11be (hereinafter referred to as "11be"), which is also known as "Extremely High Throughput (EHT)." 11bn is also known as "Ultra High Reliability (UHR)."

[0003] IEEE 802.11-23 / 0079r10, IEEE 802.11 UHR Proposed CSDIEEE 802.11-23 / 1871r2, M-AP Coordination Transmission frameworkIEEE 802.11-20 / 0410r4, Coordinated Spatial Reuse Procedure

[0004] However, the method for controlling signal transmission in wireless communication such as wireless LAN has not been fully studied.

[0005] Non-limiting embodiments of the present disclosure contribute to providing an access point, a terminal, and a communication method that can improve the efficiency of transmission control in wireless communication.

[0006] An access point according to one embodiment of the present disclosure includes a control circuit that determines parameters related to the transmission power of other access points that perform cooperative communication based on measurement information from a terminal, and a communication circuit that transmits a control signal including the parameters to the other access points.

[0007] These comprehensive or specific aspects may be realized as a system, an apparatus, a method, an integrated circuit, a computer program, or a recording medium, or may be realized as any combination of a system, an apparatus, a method, an integrated circuit, a computer program, and a recording medium.

[0008] According to an embodiment of the present disclosure, for example, it is possible to improve the efficiency of transmission control in wireless communication.

[0009] Further advantages and benefits of one embodiment of the present disclosure will become apparent from the specification and drawings. Such advantages and / or benefits may be provided by some embodiments and features described in the specification and drawings, respectively, but not necessarily all of them may be provided to obtain one or more identical features.

[0010] Diagram showing an example of a Multi-Access Point (Multi-AP) coordination sequenceBlock diagram showing an example of the configuration of a portion of an AP (Access Point)Block diagram showing an example of the configuration of a portion of a terminal (STA: Station)Diagram showing an example of a transmission and reception sequence by an AP and a STABlock diagram showing an example of the configuration of an APBlock diagram showing an example of the configuration of a STADiagram showing an example of the operation of Multi-AP coordinationDiagram showing an example of the configuration of a Basic Service Set (BSS)Diagram showing an example of a Multi-AP request signalDiagram showing an example of measurement Info included in a Multi-AP requestDiagram showing an example of a Multi-AP response signalDiagram showing an example of measurement Info included in a Multi-AP responseDiagram showing an example of optimal coordinationDiagram showing an example of rough one-way coordinationDiagram showing an example of complex one-way coordinationDiagram showing an example of transmission of a Multi-AP response signalDiagram showing an example of measurement Info included in a Multi-AP responseDiagram showing an example of a transmission sequence of rough one-way coordinationDiagram showing an example of a Measurement reportDiagram showing an example of a Multi-AP Trigger frameDiagram showing an example of a Measurement reportDiagram showing an example of a Multi-AP Trigger frameDiagram showing an example of a Multi-AP Trigger frameDiagram showing an example of a Measurement reportDiagram showing an example of a Multi-AP Trigger frameDiagram showing an example of a Complex one-way coordinationMulti-AP Trigger Figure showing an example of a Multi-AP Trigger frame Figure showing an example of a Quality of Service (QoS) Characteristics element Figure showing an example of a Traffic Specification (TSPEC) elementFigure showing an example of a Classification (TCLAS) element. Figure showing an example of an Intra Access Category element.

[0011] Hereinafter, each embodiment of the present disclosure will be described in detail with reference to the drawings.

[0012] In 11bn, Multi-AP (MAP) coordination (also called cooperative communication), in which multiple access points (also called Access Points (APs) or base stations) transmit in coordination with each other, is being discussed (see, for example, Non-Patent Document 1).

[0013] Multi-AP coordination includes various types (types or schemes) of multi-AP coordination, such as "Joint Transmission (JT)" in which multiple APs transmit the same data, "Coordinated Beamforming (C-BF)" in which interference is reduced by null control for the destination STA of other APs, "Coordinated Spatial Reuse (C-SR)" in which interference is reduced by transmission power control for the destination STA of other APs, "Coordinated Time Division Multiple Access (C-TDMA)" in which time resources are divided and shared, "Coordinated Orthogonal Frequency Division Multiple Access (C-OFDMA)" in which frequency resources are divided and shared, and "Coordinated Restricted Target Wake Time (C-rTWT)" in which the transmission period of a signal requiring low latency is coordinated. In multi-AP coordination, a multi-AP coordination sequence is being considered for APs to exchange information with other APs or terminals (STAs: Stations or non-AP Stations, hereinafter referred to as "STAs") for coordination (see, for example, Non-Patent Documents 2 and 3).

[0014] An example of a Multi-AP coordination sequence is shown in Figure 1. As shown in Figure 1, the Multi-AP coordination sequence includes the following phases:

[0015] <Cooperative AP Discovery Phase> The cooperative AP discovery phase is a phase in which an AP discovers other APs that support multi-AP coordination. For example, an AP that supports multi-AP coordination may broadcast a beacon containing a capability related to multi-AP coordination so that other APs can passively discover it. An AP may passively discover other APs that support multi-AP coordination by receiving a beacon containing a capability related to multi-AP coordination. Alternatively, for example, an AP may transmit a signal requesting a capability related to multi-AP coordination (e.g., a probe request signal including a multi-AP information element) to a specific AP to proactively discover other APs that support multi-AP coordination. The AP may also notify STAs of information about the other discovered APs. The APs and STAs described in each embodiment, specification, and drawings may each be multi-link devices (MLDs). In this case, the AP may be referred to as an AP MLD, and the STA may be referred to as a non-AP MLD. Alternatively, the AP and STA may be APs and STAs, respectively, affiliated with an MLD.

[0016] <Measurement Information Collection Phase> The measurement information collection phase is a phase in which an AP collects measurement information (hereinafter referred to as "measurement information" or "measurement report") from STAs under the AP. For example, an STA stores in a buffer the reception and measurement results of transmission signals (e.g., beacon signals transmitted by APs in a cooperative AP discovery phase, etc.) from the AP to which it belongs (also referred to as "associated") and non-associated APs. The reception and measurement results of transmission signals from the AP to which it belongs and non-associated APs may include, for example, the received signal power (Received Signal Strength Indicator (RSSI)) from the associated AP, the interference power from non-associated APs, and the signal error detection rate (Bit Error Rate (BER) or Packet Error Rate (PER)). The AP transmits a signal to the STAs under its control requesting the transmission of measurement information, including information that can be derived based on the STA's reception and measurement results (e.g., values ​​obtained by measuring the received signal and information included in the received signal) (e.g., a path loss value with respect to the AP, a Signal Interference Noise Ratio (SINR) value per frequency resource, an Acceptable Received Interference Level (ARIL) value, etc.). The STA that receives the measurement information transmission request signal transmits the measurement information to its own AP. The AP also exchanges the measurement information received from the STA with other APs. Note that, in the measurement information collection phase, an example has been described in which the STA receives a transmission signal from the AP and derives measurement information based on the received signal. However, the STA may also receive a transmission signal from a STA belonging to the same AP or a different AP and derive measurement information based on the received signal. The AP may also receive a transmission signal from another AP or STA and derive measurement information based on the received signal. Here, the operation of the STA or AP receiving a transmission signal from another STA or AP may be performed during the measurement information collection phase, or may be performed before the measurement information collection phase.Furthermore, the STA may select a transmission signal of another AP from which measurement information is derived based on information about the other AP notified by the AP to which the STA belongs.

[0017] <Coordination Negotiation Phase> The coordination negotiation phase is a phase in which an AP negotiates with other APs on whether to participate in Multi-AP coordination. For example, an AP that acquires a channel usage opportunity (Transmission Opportunity (TXOP)) (hereinafter also referred to as a "TXOP owner AP" or "Sharing AP") transmits a signal including candidates for Multi-AP coordination types and / or resource information to other APs that support Multi-AP coordination. The other APs that receive the signal transmit a signal including whether to participate in Multi-AP coordination notified by the signal to the Sharing AP. The AP that notifies that it can participate in Multi-AP coordination is controlled by the Sharing AP. The AP controlled by the Sharing AP is also called a "Shared AP."

[0018] <Coordinated Signal Transmission Phase> The coordinated signal transmission phase is a phase in which APs perform Multi-AP coordinated transmission. For example, the Sharing AP notifies the Shared AP of scheduling information including the Multi-AP coordination type and allocated resource information. The signal transmitted in the coordinated signal transmission phase according to the scheduling information (for example, referred to as a "Multi-AP coordination signal") may be a Downlink (DL) communication signal or an Uplink (UL) communication signal.

[0019] An example of a Multi-AP coordination sequence has been described above.

[0020] However, a method for controlling the Multi-AP coordination sequence (for example, a method for exchanging measurement information used in Multi-AP coordination) has not been fully studied.

[0021] In a non-limiting embodiment of the present disclosure, a method for appropriately controlling multi-AP coordination among multiple APs and improving the efficiency of multi-AP coordination will be described.

[0022] For example, in one embodiment of the present disclosure, an AP holds measurement information of a STA, and determines, based on the measurement information, whether to transmit or receive a signal related to Multi-AP coordination that includes the measurement information (for example, a Multi-AP request or a Multi-AP response, which will be described later). As a result, according to one embodiment of the present disclosure, the AP determines control information for Multi-AP coordination based on the measurement information notified from the STA, and is able to transmit or receive signals in coordination with other APs through Multi-AP coordination.

[0023] [Configuration of Wireless Communication System] A wireless communication system according to an embodiment of the present disclosure may include, for example, an AP 100 and an STA 200. In the wireless communication system, there may be two or more APs 100 and one or more STAs 200. For example, the AP 100 transmits a downlink (DL) signal to another AP or the STA 200. Furthermore, the STA 200 transmits an uplink (UL) signal based on a signal received from the AP 100.

[0024] 2 is a block diagram illustrating a configuration example of a portion of an AP 100 according to an embodiment of the present disclosure. In the AP 100 illustrated in FIG. 2, a control unit (e.g., corresponding to a control circuit) determines control information to be transmitted and received between multiple APs performing cooperative communication (Multi-AP coordination) based on measurement information (e.g., measurement information) from the STA 200. A communication unit (e.g., corresponding to a communication circuit) transmits or receives the control information.

[0025] 3 is a block diagram illustrating a configuration example of a portion of an STA 200 according to an embodiment of the present disclosure. In the STA 200 illustrated in FIG. 3, a control unit (e.g., corresponding to a control circuit) controls transmission or reception in cooperative communication, and a communication unit (e.g., corresponding to a receiving circuit or a transmitting circuit) transmits or receives control information or data in cooperative communication.

[0026] In this embodiment, multi-AP coordination is performed by a plurality of APs 100 and a plurality of STAs 200. As an example, a method will be described in which two APs 100 (e.g., AP1 and AP2) transmit and receive information related to multi-AP coordination with two STAs 200 (e.g., STA1 and STA2) and transmit a multi-AP coordination signal.

[0027] An example of the operation of the AP 100 and the STA 200 according to this embodiment will be described below.

[0028] Fig. 4 is a sequence diagram showing an example of the operation of AP 100 and STA 200 according to this embodiment. The example in Fig. 4 shows an example of the operation of BSS1, which is a network (called a Basic Service Set (BSS)) configured by AP1 and STA1, and BSS2, which is configured by AP2 and STA2.

[0029] 4, AP1 broadcasts a signal including a capability related to Multi-AP coordination (e.g., referred to as "Multi-AP coordination capability"). The signal including the Multi-AP coordination capability may be, for example, a Beacon signal or another signal. AP2 receives the Beacon signal transmitted from AP1, references the Multi-AP coordination capability, and stores information related to AP1's support for Multi-AP coordination (e.g., capability information) in a buffer.

[0030] STA1 receives a beacon signal from AP1 to which it belongs, measures the received power based on the received beacon signal, and stores the measurement result (e.g., BSS measurement information) in a buffer. STA2 receives a beacon signal from AP1, which is an overlapping BSS (OBSS), measures the received power based on the received beacon signal (e.g., the received power of a signal from a non-member AP (OBSS AP) is called "interference power"), and stores the measurement result (e.g., OBSS measurement information) in a buffer.

[0031] 4, AP2 broadcasts a signal (e.g., a Beacon signal) including the Multi-AP coordination capability. AP1 receives the Beacon signal transmitted from AP2, references the Multi-AP coordination capability, and stores information (e.g., capability information) related to AP2's support for Multi-AP coordination in a buffer.

[0032] STA1 receives a beacon signal from AP2, which is an OBSS, measures the received power (interference power) based on the received beacon signal, and stores the measurement result (e.g., OBSS measurement information) in a buffer. STA2 receives a beacon signal from AP2 to which it belongs, measures the received power (e.g., interference power) based on the received beacon signal, and stores the measurement result (e.g., BSS measurement information) in a buffer.

[0033] AP1 transmits a Measurement Report Poll signal to STA1 requesting the transmission of STA1's measurement information (referred to as Measurement Information or Measurement Report). When STA1 receives the Measurement Report Poll signal, it generates a Measurement Report including the measurement information (e.g., the received power of the transmission signal from AP1 and the interference power from the transmission signal from AP2) and transmits the Measurement Report to AP1. AP1 receives the measurement information from STA1.

[0034] Similarly, AP2 transmits a Measurement report poll signal to STA2 requesting the transmission of measurement information from STA2. When STA2 receives the Measurement report poll signal, it generates a Measurement report including measurement information (e.g., the received power of the transmission signal from AP2 and the interference power from the transmission signal from AP1) and transmits the Measurement report to AP2. AP2 receives the measurement information from STA2.

[0035] When AP1 acquires the TXOP, AP1 controls the Multi-AP coordination as a Sharing AP. For example, based on the Measurement report received from STA1, AP1 transmits a signal (e.g., referred to as a "Multi-AP request signal" or "MAP request signal") including information requesting whether or not to participate in the Multi-AP coordination controlled by AP1 to AP2 that supports Multi-AP coordination.

[0036] AP2 performs a reception process of the Multi-AP request signal. For example, AP2 may refer to the Multi-AP type or resource information included in the Multi-AP request signal to determine whether or not to participate in Multi-AP coordination. AP2, for example, transmits to AP1 a signal (e.g., referred to as a "Multi-AP response signal" or "MAP response signal") including response information indicating whether or not to participate in Multi-AP coordination. For example, in FIG. 4, the Multi-AP response signal may include response information indicating participation in Multi-AP coordination. When AP2 participates in Multi-AP coordination managed by AP1, which is a Sharing AP, AP2 is controlled by the Sharing AP as a Shared AP.

[0037] AP1 performs a receiving process of the Multi-AP response signal. For example, AP1 refers to response information included in the Multi-AP response signal, which indicates whether or not AP1 is allowed to participate in the Multi-AP coordination, and performs a scheduling process for AP1 and AP2 in the Multi-AP coordination (including, for example, determining the Multi-AP coordination type and resource information). AP1 transmits the scheduling information determined by the scheduling process (for example, "Multi-AP coordination scheduling information") to AP2. The Multi-AP coordination scheduling information may be transmitted, for example, by a Trigger frame.

[0038] Furthermore, AP1 transmits a Multi-AP coordination signal to STA1 in accordance with the determined scheduling information for AP1.

[0039] AP2 performs a process of receiving the Multi-AP coordination scheduling information transmitted from AP1. For example, AP2 transmits a Multi-AP coordination signal addressed to STA2 in accordance with the scheduling information for AP2.

[0040] STA1 performs reception processing (DL signal reception processing) of the Multi-AP coordination signal transmitted from AP1. For example, STA1 transmits a response (Acknowledge (ACK)) signal to AP1 based on the error determination result of the DL signal.

[0041] Similarly, STA2 performs reception processing (DL signal reception processing) of the Multi-AP coordination signal transmitted from AP2. For example, STA2 transmits a response (ACK) signal to AP2 based on the error determination result of the DL signal.

[0042] If AP2 does not support Multi-AP coordination, or if AP2 notifies that it cannot participate in Multi-AP coordination by using the Multi-AP coordination participation information, AP1 may cancel Multi-AP coordination. In this case, for example, AP1 may communicate independently.

[0043] Furthermore, in the Multi-AP coordination scheduling performed by AP1, the destination STA of the Multi-AP coordination signal of AP2, which is a Shared AP, and scheduling information for each destination STA (for example, Modulation and Coding Scheme (MCS) or stream information) may be determined, or resource information available to AP2 may be determined. For example, when resource information available to AP2 is determined by Multi-AP coordination scheduling, scheduling for each STA under AP2 may be determined by AP2.

[0044] Furthermore, the Multi-AP coordination scheduling may include determining the transmission timing of the Multi-AP coordination. For example, AP1 and AP2 may transmit the Multi-AP coordination signal simultaneously or at different times. The Multi-AP coordination scheduling may include the transmission power of the Multi-AP coordination. For example, AP1 may notify AP2 of the transmission power in the Multi-AP scheduling, and AP2 may transmit the Multi-AP coordination signal at the transmission power notified in the Multi-AP scheduling. The Multi-AP coordination scheduling may also include parameters related to the transmission power of the Multi-AP coordination. For example, AP1 may include parameters for AP2 to determine the transmission power in the Multi-AP scheduling, and AP2 may derive the transmission power of the Multi-AP coordination signal for AP2 based on the parameters related to the transmission power notified in the Multi-AP scheduling, and transmit the Multi-AP coordination signal.

[0045] An example of a Multi-AP coordination sequence has been described above.

[0046] [Configuration Example of AP 100] FIG. 5 is a block diagram showing a configuration example of the AP 100 (corresponding to, for example, a downlink radio transmission device) according to this embodiment.

[0047] The AP 100 shown in Figure 5 may include, for example, a radio receiving unit 101, a preamble demodulation unit 102, a data demodulation unit 103, a data decoding unit 104, a measurement information holding unit 105, a buffer status information holding unit 106, a capability information holding unit 107, a scheduling unit 108, a data generation unit 109, a data encoding unit 110, a data modulation unit 111, a preamble generation unit 112, and a radio transmission unit 113.

[0048] At least one of the preamble demodulation unit 102, data demodulation unit 103, data decoding unit 104, measurement information holding unit 105, buffer status information holding unit 106, capability information holding unit 107, scheduling unit 108, data generation unit 109, data encoding unit 110, data modulation unit 111, and preamble generation unit 112 shown in Fig. 5 may be included in the control unit shown in Fig. 2. At least one of the radio reception unit 101 and radio transmission unit 113 shown in Fig. 5 may be included in the communication unit shown in Fig. 2.

[0049] 5 , a wireless receiving unit 101 receives a signal transmitted from another AP or STA 200 (e.g., a downlink wireless receiving device) via an antenna, and performs wireless receiving processing such as down-conversion and Analog-to-Digital (A / D) conversion. The wireless receiving unit 101 divides the signal after wireless receiving processing into a preamble portion (also called a preamble signal) and a data portion (also called a data signal), and outputs the preamble signal to a preamble demodulation unit 102 and the data signal to a data demodulation unit 103.

[0050] The preamble demodulation unit 102 performs a Fourier transform (e.g., Fast Fourier Transform (FFT)) on the preamble signal input from the radio receiving unit 101 to extract reception control information used for demodulating and decoding the data signal. The reception control information may include, for example, a frequency bandwidth (BW), a modulation and coding scheme (MCS), and an error correction code. The preamble demodulation unit 102 also performs channel estimation based on a reference signal included in the preamble signal to derive a channel estimation value. The preamble demodulation unit 102 outputs the reception control information to the data demodulation unit 103 and the data decoding unit 104, and outputs the channel estimation value to the data demodulation unit 103.

[0051] Data demodulation section 103 performs FFT on the data signal input from radio receiving section 101, and demodulates the data signal using the reception control information and channel estimation value input from preamble demodulation section 102. Data demodulation section 103 outputs the demodulated data signal to data decoding section 104.

[0052] The data decoding unit 104 decodes the demodulated data signal input from the data demodulation unit 103 using the reception control information input from the preamble demodulation unit 102. The data decoding unit 104 determines whether there is an error in the decoded data signal using a method such as Cyclic Redundancy Check (CRC). If there is no error in the decoded data signal, the data decoding unit 104 outputs the decoded data signal to the measurement information holding unit 105, the buffer status information holding unit 106, the capability information holding unit 107, and the scheduling unit 108.

[0053] The measurement information holding unit 105 holds in a buffer the measurement information received from other APs 100 or STAs 200 and included in the decoded data signal input from the data decoding unit 104. For example, the measurement information holding unit 105 may include a BSS measurement information holding unit 151 that holds measurement information received from STAs 200 included in a BSS managed by the AP 100, and an OBSS measurement information holding unit 152 that holds measurement information received from APs 100 and STAs 200 included in an OBSS managed by an AP other than the AP 100. The measurement information holding unit 105 determines whether the decoded data signal has been transmitted from an AP 100 or STA 200 belonging to a BSS or an OBSS, based on, for example, an identifier (e.g., BSS color) included in the decoded data signal input from the data decoding unit 104. The measurement information holding unit 105 holds the measurement information included in the decoded data signal of the STA 200 within the BSS in the BSS measurement information holding unit 151. Furthermore, measurement information holding section 105 holds measurement information included in decoded data signals of AP 100 and STA 200 in the OBSS in OBSS measurement information holding section 152. During scheduling, measurement information holding section 105 outputs the held measurement information from BSS measurement information holding section 151 and BSS measurement information holding section 152 to scheduling section 108.

[0054] The buffer status information holding unit 106 holds in a buffer the buffer status information (e.g., buffer status report (BSR)) of other APs or STAs 200 contained in the decoded data signal input from the data decoding unit 104, and outputs the buffer status information to the scheduling unit 108.

[0055] The capability information holding section 107 holds the capability information of other APs or STAs 200 included in the decoded data signal input from the data decoding section 104 in a buffer, and outputs the capability information to the scheduling section 108 .

[0056] The scheduling unit 108 determines scheduling information (including, for example, destination information, MCS, error correction code, transmission power, parameters related to transmission power (for example, transmission power of the AP 100, allowable transmission power of the other AP 100), and transmission / reception period) for transmitting a signal to another AP or STA 200. The scheduling unit 108 may determine the MCS, error correction code, and transmission power based on, for example, measurement information input from the measurement information holding unit 105. The scheduling unit 108 may also determine destination information based on buffer status information input from the buffer status information holding unit 106 or capability information input from the capability information holding unit 107. The scheduling unit 108 outputs the scheduling information to the data generation unit 109, the data encoding unit 110, the data modulation unit 111, and the preamble generation unit 112.

[0057] The data generation unit 109 generates a data sequence to be transmitted to another AP or STA 200 based on the scheduling information input from the scheduling unit 108. For example, the data sequence to be transmitted to another AP may include a Beacon signal including capability information related to Multi-AP coordination, a signal including Multi-AP coordination participation request information (Multi-AP request signal), a signal including Multi-AP coordination participation response information (Multi-AP response signal), or a signal including Multi-AP coordination scheduling information (Multi-AP Trigger signal). For example, the data sequence to be transmitted to STA 200 may include a signal requesting transmission of measurement information (e.g., a Measurement Report Poll signal or a Beamforming Report Poll (BFRP) signal), a Buffer Status Report Poll (BSRP) signal requesting transmission of buffer status information, or a DL signal transmitted by Multi-AP coordination. The data generation unit 109 outputs the data sequence to the data encoding unit 110.

[0058] Data encoding section 110 encodes the data sequence input from data generation section 109 based on the scheduling information input from scheduling section 108 , and outputs the encoded data to data modulation section 111 .

[0059] The data modulation unit 111 performs modulation and inverse Fourier transform (IFFT) on the coded data signal input from the data coding unit 110 based on the scheduling information input from the scheduling unit 108, and outputs the modulated data signal to the radio transmission unit 113.

[0060] The preamble generating section 112 generates a preamble signal based on the scheduling information input from the scheduling section 108. The preamble generating section 112 performs modulation and IFFT processing on the preamble signal, and outputs the preamble signal to the radio transmitting section 113.

[0061] The wireless transmitting unit 113 generates a wireless frame (also called a packet signal) by adding a preamble signal input from the preamble generating unit 112 to the modulated data signal input from the data modulating unit 111. The wireless transmitting unit 113 performs wireless transmission processing such as digital-to-analog (D / A) conversion on the wireless frame and up-conversion to a carrier frequency, and transmits the signal after the wireless transmission processing to another AP or STA 200 via an antenna.

[0062] [Configuration Example of STA 200] FIG. 6 is a block diagram showing a configuration example of the STA 200 (for example, a downstream radio receiving device).

[0063] The STA 200 shown in FIG. 6 may include, for example, a radio receiving unit 201, a preamble demodulating unit 202, a data demodulating unit 203, a data decoding unit 204, a measurement control unit 205, a buffer status control unit 206, a transmission signal generating unit 207, and a radio transmitting unit 208.

[0064] At least one of the preamble demodulation unit 202, data demodulation unit 203, data decoding unit 204, measurement control unit 205, buffer status control unit 206, and transmission signal generation unit 207 shown in Figure 6 may be included in the control unit shown in Figure 3, and at least one of the radio receiving unit 201 and radio transmitting unit 208 shown in Figure 6 may be included in the communication unit shown in Figure 3.

[0065] 6 , wireless receiving section 201 receives a signal transmitted from AP 100 (e.g., a downlink wireless transmission device) via an antenna. Wireless receiving section 201 performs wireless reception processing such as down-conversion and A / D conversion of the received signal. Wireless receiving section 201 outputs a preamble signal extracted from the received signal after wireless reception processing to preamble demodulation section 202, and outputs a data signal extracted from the received signal after wireless reception processing to data demodulation section 203.

[0066] The preamble demodulation unit 202 performs an FFT on the preamble signal input from the radio reception unit 201, and extracts reception control information (including, for example, BW, MCS, and error correction code) used for demodulating and decoding the data signal (or data portion). The preamble demodulation unit 202 also performs channel estimation based on a reference signal included in the preamble signal, and derives a channel estimation value. The preamble demodulation unit 202 outputs the reception control information to the data demodulation unit 203, the data decoding unit 204, and the measurement control unit 205, and outputs the channel estimation value to the data demodulation unit 203.

[0067] The data demodulation unit 203 performs an FFT on the data signal input from the radio receiving unit 201, demodulates the data signal using the reception control information and channel estimation value input from the preamble demodulation unit 202, and outputs the demodulated data signal to the data decoding unit 204.

[0068] Data decoding section 204 decodes the demodulated data signal input from data demodulation section 203 using the reception control information input from preamble demodulation section 202. Data decoding section 204 determines whether there is an error in the decoded data signal using a method such as CRC. If there is no error in the decoded data signal, data decoding section 204 outputs the decoded data signal to measurement control section 205, buffer status control section 206, and transmission signal generation section 207.

[0069] The measurement control unit 205 may include, for example, a BSS measurement information unit 251 that calculates measurement information based on signals received from the AP 100 and the STA 200 of the BSS to which the STA 200 belongs, and an OBSS measurement information unit 252 that calculates measurement information based on signals received from the AP 100 and the STA 200 of a BSS to which the STA 200 does not belong. The measurement control unit 205 determines whether the received signal was transmitted from the AP 100 or the STA 200 of the BSS or the OBSS to which the AP 100 or the STA 200 belongs, based on the reception control information input from the preamble demodulation unit 202 and the demodulated data signal input from the data decoding unit 204. For example, in the case of a signal transmitted from the AP 100 or the STA 200 in the BSS, the measurement control unit 205 calculates measurement information (e.g., Channel State Information (CSI), Received Signal Strength Indicator (RSSI)) in the BSS measurement information unit 251 and stores the information in a buffer. Furthermore, for signals transmitted from AP 100 and STA 200 within the OBSS, the measurement control unit 205 calculates measurement information (e.g., CSI or interference power) in the OBSS measurement information unit 252 and stores the information in a buffer. The measurement control unit 205 may also calculate measurement information such as SINR or ARIL using the measurement information calculated in the BSS measurement information unit 251 and OBSS measurement information unit 252 and store the information in a buffer. The measurement control unit 205 may associate each piece of measurement information calculated in the BSS measurement information unit 251 and OBSS measurement information unit 252 with the signal identifier of the received signal for which the measurement information was calculated and store the information in a buffer.Furthermore, the measurement control unit 205 may calculate measurement information for each frequency resource in the BSS measurement information unit 251 and the OBSS measurement information unit 252. When transmission of measurement information is requested in the decoded data signal input from the data decoding unit 204 (for example, when the decoded data signal is a BFRP signal), the measurement control unit 205 outputs the measurement information held in the buffer to the transmission signal generation unit 207.

[0070] When the decoded data signal input from the data decoding unit 204 requests the transmission of STA200's UL transmission request information (e.g., a buffer status report) (e.g., when the decoded data signal is a BSRP signal), the buffer status control unit 206 outputs the UL transmission request information to the transmission signal generation unit 207.

[0071] The transmission signal generation unit 207 generates a data sequence to be transmitted to the AP 100 based on the decoded data signal input from the data decoding unit 204. For example, the data sequence to be transmitted to the AP 100 may include a response signal (ACK or Block ACK (BA)) to the signal received from the AP 100. Furthermore, if the decoded data signal input from the data decoding unit 204 includes a signal requesting transmission of measurement information (e.g., a BFRP signal), the transmission signal generation unit 207 may include measurement information in the data sequence to be transmitted to the AP 100. Furthermore, if the decoded data signal input from the data decoding unit 204 includes a signal requesting transmission of buffer status information (e.g., a BSRP signal), the transmission signal generation unit 207 may include UL transmission request information in the data sequence to be transmitted to the AP 100. The transmission signal generation unit 207 encodes the generated data sequence and generates a data signal by performing modulation and IFFT processing on a predetermined frequency resource. The transmission signal generation unit 207 adds a preamble signal to the data signal to generate a radio frame, and outputs the radio frame to the radio transmission unit 208 .

[0072] The wireless transmission unit 208 performs wireless transmission processing such as D / A conversion or upconversion to a carrier frequency on the wireless frame input from the transmission signal generation unit 207, and transmits the signal after wireless transmission processing to the AP 100 via an antenna.

[0073] The above describes exemplary configurations of the AP 100 and the STA 200.

[0074] [Example of Operation of AP 100 and STA 200] An example of operation regarding Multi-AP coordination in the AP 100 and the STA 200 will be described below.

[0075] For example, in one embodiment of the present disclosure, AP 100 exchanges measurement information using participation request information for Multi-AP coordination (Multi-AP request signal) and participation response information for Multi-AP coordination (Multi-AP response signal).

[0076] For example, in the measurement information collection phase, AP 100 does not transmit measurement information to other APs or receive measurement information from other APs, but in the coordination negotiation phase, APs transmit and receive Multi-AP request signals containing measurement information and Multi-AP response signals containing measurement information. For example, AP 100 may transmit measurement information contained in Multi-AP request signals to other APs and receive measurement information contained in Multi-AP response signals from other APs. Also, for example, AP 100 may receive measurement information contained in Multi-AP request signals from other APs and transmit measurement information contained in Multi-AP response signals to other APs.

[0077] Fig. 7 shows an example of the operation of AP 100 and STA 200. In the example of Fig. 7, as shown in Fig. 8, an example of the operation of BSS1 consisting of AP1 and STA1 belonging to AP1, and BSS2 consisting of AP2 and STA2 belonging to AP2 is shown. Furthermore, the arrows shown in Fig. 8 indicate a) the route (path) between AP1 and STA1, b) the path between AP2 and STA2, c) the path between AP1 and STA2, and d) the path between AP2 and STA1.

[0078] In Fig. 7, AP1 and AP2 each transmit a beacon signal. At this time, STA1 and STA2 acquire (or generate) measurement information based on the beacon signals from AP1 and AP2. For example, STA1 generates BSS measurement information (e.g., measurement information related to the path indicated by a) in Fig. 8) using the beacon signal from AP1, and generates OBSS measurement information (e.g., measurement information related to the path indicated by d) in Fig. 8) using the beacon signal from AP2. Similarly, for example, STA2 generates BSS measurement information (e.g., measurement information related to the path indicated by b) in Fig. 8) using the beacon signal from AP2, and generates OBSS measurement information (e.g., measurement information related to the path indicated by c) in Fig. 8) using the beacon signal from AP1.

[0079] The AP 100 may notify the subordinate STAs 200 of the APs whose measurement information it will measure. For example, the AP 100 may notify the subordinate STAs 200 that it will acquire measurement information in response to a signal transmitted by an AP that supports multi-AP coordination (in other words, has the capability for multi-AP coordination). Whether or not to measure measurement information for each AP may be determined based on whether the AP belongs to a common multi-AP coordination group (referred to as an AP candidate set or virtual BSS). For example, the AP 100 may notify the STAs 200 of the APs whose measurement information it will measure by transmitting a beacon signal to the STAs 200 that includes identifiers of all APs belonging to the multi-AP coordination group (referred to as a multi-AP coordination group list). In other words, the AP 100 may notify the STAs 200 that it will not measure measurement information for APs not included in the multi-AP coordination group list. Furthermore, whether or not to measure measurement information may be notified based on whether or not the AP has the same coordination group ID as the AP to which it belongs. For example, the AP 100 transmits a beacon signal including the coordination group ID to which the AP 100 belongs. By receiving a beacon signal, STA 200 determines the coordination group ID of AP 100 to which STA 200 belongs. If the coordination group ID included in a signal received from another AP is the same as the coordination group ID of AP 100 to which STA 200 belongs, STA 200 measures measurement information, and if it is different from the coordination group ID of AP 100 to which STA 200 belongs, STA 200 does not measure the measurement information.

[0080] In FIG. 7 , AP1 transmits a Measurement Report Poll signal to STA1, and AP2 transmits a Measurement Report Poll signal to STA2. When STA1 receives the Measurement Report Poll signal from AP1, it transmits a Measurement Report to AP1, including measurement information (e.g., path loss values) of paths a) and d) shown in FIG. 8 . When STA2 receives the Measurement Report Poll signal from AP2, it transmits a Measurement Report to AP2, including measurement information (e.g., path loss values) of paths b) and c) shown in FIG. 8 . As an example, each path loss value may be derived from the difference between the transmission power value included in the beacon signal received by each STA from each AP and the received power value of the beacon signal measured by each STA. Furthermore, AP100 may notify STA200, using the Measurement Report Poll signal, that it will transmit a Measurement Report including the received power value of each beacon signal. At this time, the AP 100 may derive a path loss value from the difference between the transmission power value of the beacon signal transmitted by the AP 100 and the received power value of the beacon signal notified by the STA 200. In another example, the AP may transmit an NDPA (Null Data PPDU Announcement) frame and an NDP (Null Data PPDU) signal (not shown). Each path loss value may be derived from the difference between the transmission power value included in the NDPA or other notification signal (e.g., a management frame) received by each STA from each AP and the received power value measured by each STA after receiving the NDP. Hereinafter, an example will be described in which the STA derives measurement information based on the received power value and interference power value obtained using a beacon signal during the measurement information collection phase. However, the measurement information collection phase may be performed based on information obtained using an NDP or data frame instead of a beacon signal. The beacon, NDP, NDPA, data frame, etc. may be transmitted before or during the measurement information collection phase.

[0081] In FIG. 7 , for example, AP1 serves as the Sharing AP and manages Multi-AP coordination. In this case, AP1 notifies AP2 of whether or not to participate in Multi-AP coordination by transmitting a Multi-AP request signal including measurement information. The measurement information included in the Multi-AP request signal may include, for example, a path loss value between the destination STA (STA1) of the Sharing AP (AP1) and the Shared AP (AP2), and the ARIL value of the destination STA (STA1) of the Sharing AP (AP1). The ARIL value of STA1 may be derived by STA1 from the received power value of a signal received by STA1 from its serving AP (AP1) or the received power value of a signal received by STA1 from its serving AP (AP1) in cooperative transmission (which may be derived from the transmission power value and path loss value of a signal transmitted by the serving AP (AP1) in cooperative transmission), and the signal error rate of the received signal. For example, STA1 may derive the ARIL value based on the SINR value at which the packet error rate of STA1 is 10% or less, and include the ARIL value in the measurement information. The AP may notify the STAs in advance of information about the transmission power and MCS to be used in the cooperative transmission, and the STAs may derive an ARIL value for the cooperative transmission based on the transmission power and MCS information notified by the AP. Alternatively, the ARIL value of STA1 may not be included in the measurement information but may be derived by AP 100 from other measurement information. For example, STA1 notifies AP1 of the measurement information including the received power value of a signal received from its serving AP (AP1), the interference power value of a signal received from a non-serving AP (AP2), and the path loss value between each AP. At this time, AP1 derives the ARIL value of STA1 from the SINR value that makes the packet error rate of STA1 10% or less based on the transmission rate of STA1's response (ACK) signal (in other words, the packet error rate of STA1) and the measurement information notified by STA1. The ARIL value may be derived for each MCS of the signal received by STA1.

[0082] 7, AP2 transmits information indicating whether or not it is willing to participate in Multi-AP coordination to AP1 in a Multi-AP response signal. If AP2 is willing to participate in Multi-AP coordination, the Multi-AP response signal may include measurement information. The measurement information included in the Multi-AP response signal may include a path loss value between the Shared AP (AP2) and the destination STA (STA2) of the Shared AP (AP2), a path loss value between the Sharing AP (AP1) and the destination STA (STA2) of the Shared AP (AP2), and an ARIL value of the destination STA (STA2) of the Shared AP (AP2).

[0083] 7, AP1, which is the Sharing AP, performs scheduling based on measurement information exchanged with AP2, and notifies AP2 of the Multi-AP coordination type (e.g., JT, C-SR, C-BF, C-OFDMA, etc.) and scheduling information using a Multi-AP Trigger signal (Trigger frame). AP1, which is the Sharing AP, and AP2, which is the Shared AP, transmit data to subordinate STAs 1 and 2 using Multi-AP coordination based on the scheduling information included in the Multi-AP Trigger signal.

[0084] In the example of Figure 7, an example was described in which one Sharing AP and one Shared AP send and receive a Multi-AP request signal and a Multi-AP response signal, but there may be multiple Shared APs, and the Multi-AP request signal may be a transmission signal addressed to multiple Shared APs.

[0085] <Example of Multi-AP Request Signal> FIG. 9 shows an example of a Multi-AP request signal.

[0086] 9, the "Request MAP type" subfield notifies, for example, information about the type of Multi-AP coordination requested by the Sharing AP (for example, JT, C-SR, C-BF, C-OFDMA, etc.). Also, the "Multi-AP subtype" subfield notifies, for example, when the type of Multi-AP coordination notified in the Request MAP type has multiple control options (also called "subtypes" or "options"), information about the control option type.

[0087] The "Number of Shared APs" subfield reports, for example, information regarding the number of Shared APs to which the Multi-AP request signal is addressed. The "Shared AP ID" subfield reports information regarding the identifiers (AP IDs) of the Shared APs, the number of which is equal to the number of Shared APs reported in the "Number of Shared APs" subfield.

[0088] The "Measurement Info" subfield notifies, for example, measurement information (for example, path loss value, ARIL) related to a STA belonging to the Sharing AP (a destination STA of the Sharing AP).

[0089] FIG. 10 shows an example of the Measurement Info subfield included in the Multi-AP request signal.

[0090] In FIG. 10, the "Number of STA" subfield notifies information regarding the number of destination STAs of the sharing AP.

[0091] The "STA Info" subfield includes, for example, a number equal to the number of STAs notified in the Number of STA subfield. The STA Info subfield includes, for example, a "STA ID" subfield that notifies an identifier for each STA, an "ARIL" subfield that notifies an ARIL value for each STA, and a "Pathloss" subfield that notifies a pathloss value between the STA and the Shared AP. For example, the Pathloss subfield shown in FIG. 10 includes pathloss values ​​between N STAs notified in the Number of STA subfield (FIG. 10) and M Shared APs notified in the Number of Shared AP subfield (FIG. 9).

[0092] <Example of Multi-AP response signal> FIG. 11 shows an example of a Multi-AP response signal.

[0093] In FIG. 11, the "MAP type response" subfield indicates whether or not participation in communication of the Multi-AP coordination type notified by the Multi-AP request signal is permitted.

[0094] The "Measurement Info" subfield notifies, for example, measurement information (for example, path loss value, ARIL) related to a STA belonging to the Shared AP (a destination STA of the Shared AP).

[0095] FIG. 12 shows an example of the Measurement Info subfield included in the Multi-AP response signal.

[0096] In FIG. 12, the "Number of STAs" subfield notifies information regarding the number of destination STAs of the Shared AP.

[0097] The "STA Info" subfield includes, for example, a number equal to the number of STAs notified in the "Number of STA" subfield. The STA Info subfield includes, for example, a "STA ID" subfield notifying an identifier for each STA, an "ARIL" subfield notifying an ARIL value for each STA, and a "Pathloss" subfield notifying a pathloss value between the STA and the Sharing AP.

[0098] Examples of the Multi-AP request signal and the Multi-AP response signal have been described above.

[0099] For example, the destination STA of the Sharing AP included in the Multi-AP request signal may be determined by the Sharing AP based on buffer status information received by the Sharing AP from the STA. Similarly, the destination STA of the Shared AP included in the Multi-AP response signal may be determined by the Shared AP based on buffer status information received by the Shared AP from the STA.

[0100] In this embodiment, the AP 100 determines control information to be transmitted and received between multiple APs performing multi-AP cooperative communication (multi-AP coordination) based on measurement information from the STAs 200, and transmits or receives the determined control information. For example, measurement information of the APs 100 and the STAs 200 related to multi-AP cooperative communication is transmitted and received (or exchanged) between multiple APs 100, while measurement information of the APs 100 and the STAs 200 not related to multi-AP cooperative communication does not need to be transmitted and received (or exchanged). As a result, for example, during the measurement information collection phase, measurement information of all APs 100 and the STAs 200 does not need to be exchanged between the APs 100, thereby reducing measurement information overhead. Therefore, this embodiment can improve the efficiency of transmission control (e.g., multi-AP coordination) in wireless communication.

[0101] [Variation 1] The measurement information included in the Multi-AP request signal may be determined (or changed) based on the type of Multi-AP cooperation method included in the Multi-AP request signal and the subtype (or option) for each Multi-AP cooperation method.

[0102] For example, when C-SR is notified by the Request MAP type subfield of the Multi-AP request signal shown in Fig. 9, the Multi-AP subtype subfield may notify one of optimal coordination, rough one-way coordination, and complex one-way coordination. Note that optimal coordination is also called "full coordination," "two-way coordination," or "bi-directional coordination." One-way coordination is also called, for example, "half-coordination," "restricted coordination," or "uni-directional coordination." Rough one-way coordination is also called "simple one-way coordination."

[0103] 13 shows an example of the operation of optimal coordination. Optimal coordination is a C-SR transmission control method in which a Shared AP (AP2 in the example of FIG. 13) aggregates measurement information collected from subordinate STAs to a Sharing AP (AP1 in the example of FIG. 13), and the Sharing AP determines the transmission power of each AP so as to reduce residual interference with the destination STA of each AP. For example, a Multi-AP request signal in which C-SR is notified in the Request MAP type subfield and optimal coordination is notified in the Multi-AP subtype subfield does not need to include the measurement info subfield. The transmission power of each Shared AP determined by the Sharing AP is included in the scheduling information of a Multi-Ap Trigger signal and notified to the Shared AP.

[0104] 14 shows an example of the operation of Rough one-way coordination. Rough one-way coordination is a C-SR transmission control method in which a Shared AP (AP2 in the example of FIG. 14) determines the transmission power of the Shared AP so as to reduce residual interference with the destination STA of the Sharing AP (AP1 in the example of FIG. 14). In Rough one-way coordination, the Sharing AP determines the transmission power of the Sharing AP without using measurement information of the Shared AP. The Shared AP determines the transmission power of the Shared AP based on the measurement information notified by the Sharing AP. For example, a Multi-AP request signal in which C-SR is notified in the Request MAP type subfield and rough one-way coordination is notified in the Multi-AP subtype subfield may include a measurement Info subfield that includes the ARIL of the destination STA of the Sharing AP and a path loss value between the destination STA of the Sharing AP and each Shared AP. The Shared AP may determine the transmit power of the Shared AP so as to reduce interference to the Sharing AP's destination STA based on the ARIL of the Sharing AP's destination STA notified in the Multi-AP request signal and the path loss value between the Sharing AP's destination STA and the Shared AP. Alternatively, the Sharing AP may determine the transmit power of the Shared AP based on the ARIL of the Sharing AP's destination STA and the path loss value between the Sharing AP's destination STA and the Shared AP, and notify the determined transmit power in the Multi-AP request signal. Note that rough one-way coordination may also be selected as a cooperative control method between one Sharing AP and two or more Shared APs. In this case, each Shared AP determines the transmit power of the Shared AP without using measurement information from the other Shared APs.For example, the Shared AP determines the transmission power that reduces residual interference to the destination STA of the Sharing AP, and does not need to consider interference to the destination STA of other Shared APs.

[0105] Figure 15 shows an example of the operation of Complex one-way coordination. Complex one-way coordination is a C-SR transmission control method in which one Sharing AP (AP1 in the example of Figure 15) and two or more Shared APs (AP2 and AP3 in the example of Figure 15) cooperate. In Complex one-way coordination, a Shared AP determines the transmission power of the Shared AP so as to reduce residual interference with the destination STA of the Sharing AP and the destination STAs of other Shared APs. Also, in Complex one-way coordination, the Sharing AP determines the transmission power of the Sharing AP without using measurement information of the Shared AP. Also, the Shared AP determines the transmission power of the Shared AP based on measurement information notified by the Sharing AP and measurement information received from other Shared APs. For example, a Multi-AP request signal in which C-SR is notified in the Request MAP type subfield and complex one-way coordination is notified in the Multi-AP subtype subfield may include a measurement Info subfield containing the ARIL of the destination STA of the Sharing AP and the path loss value between the destination STA of the Sharing AP and each Shared AP.

[0106] In Variation 1, measurement information used (or referenced) in the applied Multi-AP cooperation method type and subtype of the Multi-AP cooperation type is reported in the Multi-AP request signal, and measurement information not used in the Multi-AP cooperation method type and subtype of the Multi-AP cooperation type is not reported, thereby reducing the overhead of the Multi-AP request signal.

[0107] [Variation 2] The measurement information included in the Multi-AP response signal may be determined (or changed) based on the type of Multi-AP cooperation method included in the Multi-AP request signal and the subtype (or option) for each Multi-AP cooperation method.

[0108] For example, when a Shared AP receives a Multi-AP request signal in which C-SR is notified in the Request MAP type subfield and Optimal coordination is notified in the Multi-AP subtype subfield, if the Shared AP wishes to participate in the optimal coordination of C-SR, the Shared AP transmits a Multi-AP response signal to the Sharing AP, the signal including in the measurement Info subfield the ARIL of the Shared AP's destination STA, the path loss value between the Sharing AP and the Shared AP's destination STA, and the path loss value between the Shared AP and the Shared AP's destination STA.

[0109] Furthermore, for example, a Shared AP that receives a Multi-AP request signal in which C-SR is notified in the Request MAP type subfield and rough one-way coordination is notified in the Multi-AP subtype subfield does not need to include the measurement Info subfield in the Multi-AP response signal when participating in the rough one-way coordination of C-SR.

[0110] Furthermore, for example, when a Shared AP receives a Multi-AP request signal in which C-SR is notified in the Request MAP type subfield and complex one-way coordination is notified in the Multi-AP subtype subfield, when participating in the complex one-way coordination of C-SR, the Shared AP may transmit a Multi-AP response signal to the Sharing AP and other Shared APs, the Multi-AP response signal including the ARIL of the Shared AP's destination STA and the path loss value between the Shared AP's destination STA and other Shared APs in the measurement Info subfield.

[0111] FIG. 16 shows an example of transmitting a Multi-AP response signal in complex one-way coordination. In FIG. 16, Shared APs (AP2, AP3) transmit Multi-AP response signals to a Sharing AP (AP1) and other Shared APs (AP3, AP2). At this time, the Sharing AP may notify the order in which the Shared APs transmit the Multi-AP response signals using a Multi-AP request signal. For example, the order in which the Sharing AP ID subfields of the Multi-AP request signal transmit the Multi-AP response signals may be notified. FIG. 17 shows an example of measurement info included in a Multi-AP request signal in complex one-way coordination. The measurement info (STA Info subfield) shown in FIG. 17 may include an identifier of the Shared AP's destination STA ("STA ID" subfield), an ARIL value of the Shared AP's destination STA ("ARIL" subfield), and a path loss value between the Shared AP's destination STA and other Shared APs ("Pathloss" subfield).

[0112] In variation 2, the measurement information used for each Multi-AP cooperation method type and subtype of the Multi-AP cooperation type notified by the Multi-AP request signal is notified by the Multi-AP response signal, and measurement information that is not used in the Multi-AP cooperation method type and Multi-AP cooperation type notified by the Multi-AP request signal is not notified. This reduces the overhead of the Multi-AP response signal.

[0113] [Variation 3] The type of multi-AP cooperation method may be determined based on measurement information transmitted by the STA 200 .

[0114] For example, the Sharing AP may determine the transmission in joint transmission and the Shared AP as a candidate for cooperation based on path loss information between the Shared AP and STA200 contained in measurement information received from STA200 under the Sharing AP (e.g., based on a comparison of the path loss value with a threshold).

[0115] Also, for example, the Sharing AP may determine transmission in C-SR and the Shared AP as a candidate for cooperation based on the interference power value or SINR value included in the measurement information (e.g., based on a comparison of the interference power value or SINR value with a threshold value).

[0116] Variation 3 allows the Sharing AP to determine the type of multi-AP cooperation method using only the measurement information of STA 200 under the Sharing AP. In other words, the Sharing AP can determine the type of multi-AP cooperation method without using the measurement information of STA 200 under the Shared AP. This reduces the overhead of the measurement information used to determine the type of multi-AP cooperation method.

[0117] [Variation 4] The subtype for each multi-AP cooperation type may be determined based on measurement information transmitted by STA 200. For example, the Sharing AP may determine the multi-AP cooperation type of C-SR (e.g., optimal coordination, rough one-way coordination, or complex one-way coordination) based on the difference between the path loss value between the Sharing AP and STA 200 included in the measurement information received from the STA under the Sharing AP and the path loss value between the Shared AP and STA 200 (e.g., based on comparison of the difference with a threshold). For example, the Sharing AP may determine the multi-AP cooperation type of C-SR depending on whether the difference in the path loss values ​​exceeds a threshold.

[0118] Variation 4 allows the Sharing AP to determine the subtype of the Multi-AP cooperation method type using only the measurement information of the STAs under the Sharing AP. In other words, the Sharing AP can determine the subtype of the Multi-AP cooperation method type without using the measurement information of the STAs under the Shared AP. This reduces the overhead of the measurement information used to determine the subtype of the Multi-AP cooperation method type.

[0119] [Variation 5] The measurement information included in the Multi-AP request signal or the measurement information included in the Multi-AP response signal may be determined based on the measurement information transmitted by the STA 200 .

[0120] For example, STA200 may derive the transmission power value of AP100 based on the received power and signal error determination rate of the signal received from AP100 to which it belongs, and the interference power of the signal received from non-AP100, and notify the AP100 to which it belongs by including it in measurement information.

[0121] The transmission power value of AP 100 notified in the measurement information may be, for example, information notifying the recommended minimum transmission power value of AP 100 to which STA 200 belongs. When AP 100 receives measurement information including the recommended minimum transmission power from subordinate STA 200, AP 100 may transmit a signal to STA 200 at the recommended minimum transmission power, or may determine a transmission power equal to or greater than the recommended minimum transmission power based on the recommended minimum transmission power and transmit the signal to STA 200.

[0122] Furthermore, the transmission power value of AP 100 that is included in the measurement information and notified may be, for example, information notifying the recommended maximum transmission power value of another AP 100 to which STA 200 does not belong. When AP 100 receives measurement information including a recommended maximum transmission power value from a subordinate STA 200, it may notify the other AP 100 by including the recommended maximum transmission power value received from STA 200 in the measurement information of a Multi-AP request signal or a Multi-AP response signal. The other AP 100 may transmit a signal to the other STA 200 using the recommended maximum transmission power notified in the measurement information, or may determine a transmission power that is equal to or less than the recommended maximum transmission power based on the recommended maximum transmission power and transmit a signal to the other STA 200.

[0123] The measurement information transmitted by STA 200 to AP 100 may include both the recommended minimum transmission power value of AP 100 and the maximum transmission power of another AP 100, or may include transmission power information for either one of them.

[0124] Variation 5 allows STA 200 to determine the transmission power of each AP 100 based on measurement information, thereby reducing the amount of information to be included in the measurement information.

[0125] [Variation 6] Whether to transmit and receive a Multi-AP request signal and a Multi-AP response signal may be determined based on the subtype of each Multi-AP cooperation type.

[0126] For example, if the Sharing AP determines to transmit C-SRs in optimal coordination based on the measurement information, it may determine to transmit and receive a Multi-AP request signal and a Multi-AP response signal. In this case, the Sharing AP transmits a Multi-AP request signal to the Shared AP, and the Shared AP that receives the Multi-AP request signal transmits a Multi-AP response signal to the Sharing AP.

[0127] Furthermore, for example, when the Sharing AP determines to cooperatively transmit a C-SR using rough one-way coordination based on the measurement information, it may decide not to transmit and receive a Multi-AP request signal and a Multi-AP response signal. In this case, the Sharing AP may omit transmitting the Multi-AP request signal, and the Shared AP may omit transmitting the Multi-AP response signal. Figure 18 shows an example of a transmission sequence when the subtype of the Multi-AP cooperation type (C-SR) is rough one-way coordination. When cooperatively transmitting using rough one-way coordination, the Sharing AP may omit transmitting the Multi-AP request signal and receiving the Multi-AP response signal, and may notify the measurement information (measurement info) using a MAP Trigger signal. The measurement info included in the trigger frame may include, for example, the ARIL of the destination STA of the Sharing AP and the path loss value between the destination STA of the Sharing AP and the Shared AP.

[0128] Furthermore, for example, if the Sharing AP determines to cooperatively transmit C-SRs using complex one-way coordination based on the measurement information, it may determine to transmit and receive a Multi-AP request signal and a Multi-AP response signal. In this case, the Sharing AP transmits a Multi-AP request signal to the Shared AP, and the Shared AP that receives the Multi-AP request signal transmits a Multi-AP response signal to the Sharing AP and other Shared APs.

[0129] Variation 6 determines the transmission of Multi-AP request signals and Multi-AP response signals based on the subtype for each Multi-AP coordination type, thereby reducing the transmission of unnecessary Multi-AP request signals and Multi-AP response signals, thereby reducing the overhead of Multi-AP coordination.

[0130] One embodiment of the present disclosure has been described above.

[0131] In another embodiment, the AP 100 notifies or exchanges the allowable transmission power value of the other AP (information on the transmission power of the other AP) using at least one of a Multi-AP request signal, a Multi-AP response signal, and a Multi-AP Trigger signal. The allowable transmission power value of the other AP indicates, for example, the upper limit of the transmission power of the other AP.

[0132] For example, in the measurement information collection phase, AP 100 does not send measurement information to other APs or receive measurement information from other APs, and in the cooperative negotiation phase, APs send and receive a Multi-AP request signal including an allowable transmission power value, a Multi-AP response signal including an allowable transmission power value, or a Multi-AP Trigger signal including an allowable transmission power value.

[0133] For example, AP 100 may transmit the allowable transmission power value included in the Multi-AP request signal and the allowable transmission power value included in the Multi-AP Trigger signal to another AP, and receive the allowable transmission power value included in the Multi-AP response signal from another AP.Also, for example, AP 100 may receive the allowable transmission power value included in the Multi-AP request signal and the allowable transmission power value included in the Multi-AP Trigger signal from another AP, and transmit the allowable transmission power value included in the Multi-AP response signal to another AP.

[0134] The AP 100 may determine the allowable transmission power value of other APs that perform multi-AP cooperative communication based on, for example, a measurement report from the STA 200 .

[0135] For example, when the subtype of the Multi-AP cooperation type (e.g., C-SR) is rough one-way coordination, the operation example of AP100 and STA200 regarding notification of the allowable transmission power value may be similar to the operation example (example of transmission sequence) shown in Figure 18.

[0136] In FIG. 18 , AP1 and AP2 each transmit a beacon signal. STA1 and STA2 acquire (or generate) measurement information based on the beacon signals from AP1 and AP2. For example, STA1 generates measurement information (e.g., RSSI) related to received signal power using the beacon signal from AP2. Similarly, for example, STA2 generates measurement information related to received signal power using the beacon signal from AP1. In addition, STA1 may extract and store beacon signal transmission power information included in the beacon signal from AP2, and STA2 may extract and store beacon signal transmission power information included in the beacon signal from AP1. Furthermore, STA1 may calculate and store the path loss between AP2 and STA1 based on the received signal power information and transmission power information of the beacon signal from AP2, and STA2 may calculate and store the path loss between AP1 and STA2 based on the received signal power information and transmission power information of the beacon signal from AP1.

[0137] In Fig. 18, AP1 transmits a Measurement report poll signal to STA1, and AP2 transmits a Measurement report poll signal to STA2. When STA1 receives the Measurement report poll signal from AP1, it includes an RSSI generated using a beacon signal from AP2 in a Measurement report and transmits the resulting report to AP1. When STA2 receives the Measurement report poll signal from AP2, it includes an RSSI generated using a beacon signal from AP1 in a Measurement report and transmits the resulting report to AP2. Fig. 19 shows an example of a Measurement report transmitted by STA200 (e.g., STA1, STA2). The Measurement report shown in Fig. 19 includes, for example, the transmission power value of the Measurement report by STA200 ("STA Tx power" subfield), the number of OBSS APs included in the Measurement report ("Number of OBSS AP" subfield), and one or more pieces of OBSS information ("OBSS Info" field). Each OBSS information includes an identifier of the corresponding OBSS AP ("AP ID" subfield) and an RSSI generated using the beacon signal of the corresponding OBSS AP ("RSSI" subfield). In addition, each OBSS information may include beacon signal transmission power information of the corresponding OBSS AP. Each OBSS information may also include path loss information between the corresponding OBSS AP and the STA.

[0138] In FIG. 18 , for example, AP1 serves as the Sharing AP and manages Multi-AP coordination. In this case, when AP1 determines to cooperatively transmit C-SR using rough online coordination based on the Measurement report received from STA1, it may transmit a Multi-AP Trigger signal including the transmission power value of AP1 and the allowable transmission power value of AP2 (a parameter related to the transmission power of AP2). FIG. 20 shows an example of a Multi-AP Trigger signal (e.g., a Common Info field and a User Info field). The Multi-AP Trigger signal shown in FIG. 20 includes, for example, a Multi-AP cooperative communication method ("Multi-AP Type" subfield), a subtype of the Multi-AP cooperative communication method ("Multi-AP subtype" subfield), and a transmission power value of the Sharing AP during Multi-AP cooperative communication ("Sharing AP Tx power" subfield) in the common information section (Common Info field). Furthermore, the Multi-AP Trigger signal includes, for example, user information of one or more Shared APs in the user information section (User Info field). The user information of a Shared AP includes an identifier of the corresponding Shared AP ("Shared AP ID" subfield) and an acceptable transmission power value of the corresponding Shared AP (Acceptable Tx power subfield).

[0139] For example, AP1 may determine its transmission power value (for example, the value of the Sharing AP Tx power subfield) based on the path loss value between AP1 and STA1. The path loss value between AP1 and STA1 may be derived based on, for example, the received power value of a signal received from STA1 (for example, a Measurement report) and the transmit power value of the Measurement report included in the Measurement report (for example, the value of the STA Tx power subfield in FIG. 19). Also, for example, AP1 may determine its transmit power so that the SINR of STA1 satisfies a predetermined quality (desired reception quality, for example, an SINR that results in a packet error rate of 10% or less). For example, the transmit power value of AP1, which is a Sharing AP, may be derived according to equation (1). In equation (1), TxPower AP1 indicates the transmission power value of AP1, and IN STA1,max indicates the maximum interference noise power received by STA1 from AP2 (e.g., the RSSI of the beacon signal of AP2 notified by STA1 in a measurement report), and SINR required indicates the SINR required for STA1 to receive a given MCS, and Pathloss AP1,STA1 indicates the path loss value between AP1 and STA1. TxPower AP1 = IN STA1,max + SINR required + Pathloss AP1,STA1 (1)

[0140] Alternatively, AP1 may receive link margin information from STA1 and determine the transmission power of the cooperative transmission. For example, when AP1 transmits a signal to STA1 and receives link margin information based on a signal quality evaluation when STA1 receives the signal, AP1 determines the transmission power of the signal transmitted to STA1 as the transmission power (TxPower AP1) The link margin information is the surplus received power value required to satisfy a predetermined reception quality, and is expressed by equation (2). In equation (2), the received signal detection threshold is, for example, Clear Channel Assessment-Energy Detect (CCA-ED). LinkMargin = Received signal power - Received signal detection threshold (2)

[0141] In addition, the transmission power of AP1 is not limited to control based on feedback information from STA1, such as measurement reports and link margin information, but may be determined by AP1 based on AP1's control policy (e.g., low power consumption control, communication reliability control (QoS: Quality of Service, etc.), etc.).

[0142] Furthermore, AP1 may determine the allowable transmission power (e.g., the value of the Acceptable Tx power subfield) of AP2, which is a Shared AP, based on, for example, the interference power (e.g., the allowable interference power) of STA200 (e.g., STA1) that satisfies a predetermined quality with the transmission power of AP1 described above. For example, the allowable transmission power of AP2, which is a Shared AP, may be derived according to equation (3). In equation (3), AcceptableTxPower AP2 indicates the allowable transmission power of AP2, and ARIL STA1 indicates the allowable interference power of STA1, and Pathloss AP2,STA1 indicates the path loss value between AP2 and STA1. AcceptableTxPower AP2 = ARIL STA1 + Pathloss AP2,STA1 (3)

[0143] In addition, ARIL STA1 may be derived, for example, according to equation (4). STA1 = TxPower AP1 - Pathloss AP1,STA1 - SINR required (4)

[0144] For example, the allowable transmission power of AP2 may be derived as an absolute value. For example, AP1 may derive a path loss value between AP2 and STA1 based on transmission power information of AP2 included in a beacon signal received from AP2 and the RSSI (e.g., the received power value at STA1) of the beacon signal received by STA1 from AP2, which is included in a measurement report received from STA1. Alternatively, STA1 may include transmission power information of the beacon signal of AP2 in a measurement report and transmit it to AP1, and AP1 may derive a path loss value between AP2 and STA1 based on the transmission power information of the beacon signal of AP2 included in the measurement report received from STA1 and the RSSI of the beacon signal of AP2 measured by STA1. As yet another method, STA1 may include path loss information between AP2 and STA1 in a measurement report, and AP1 may obtain a path loss value based on the path loss information included in the measurement report received from STA1. AP1 may derive the upper limit of AP2's transmission power as AP2's allowable transmission power, for example, based on the derived path loss value between AP2 and STA1 and STA1's desired SINR (for example, the SINR value at which the packet error rate is 10% or less).

[0145] Furthermore, for example, the allowable transmission power of AP2 may be derived as a relative value. For example, AP1 may derive the amount of change in the transmission power of AP2 (in other words, the relative value of the transmission power of AP2's coordinated transmission in Multi-AP coordination to the transmission power of AP2's beacon signal) as the allowable transmission power of AP2 based on (e.g., using RSSI as a reference) the RSSI (e.g., the received power value at STA1) of the beacon signal received by STA1 from AP2, which is included in the Measurement report received from STA1. In this case, for example, each AP 100 (e.g., including AP2) may store the transmission power value of the most recently transmitted beacon signal in a buffer. AP2 may determine the transmission power value of AP2 based on, for example, the transmission power value stored in the buffer and the allowable transmission power value, which is a relative value (e.g., the amount of change in AP2's transmission power).

[0146] AP1 notifies the other APs of a Multi-AP Trigger signal including transmission power information of AP1 (for example, a value of Sharing AP Tx power) and allowable transmission power information for each of the other APs (for example, a value of Acceptable Tx power).

[0147] 18 , AP2 determines a destination STA (e.g., STA2) with which it can communicate using a transmission power equal to or less than AP2's allowable transmission power value, as indicated in the Multi-AP Trigger signal received from AP1. For example, if the Multi-AP Trigger signal received from AP1 notifies AP2 of an absolute allowable transmission power value, AP2 may determine its transmission power value based on the absolute allowable transmission power value. Furthermore, if the Multi-AP Trigger signal received from AP1 notifies AP2 of a relative allowable transmission power value, AP2 may determine its transmission power value based on the transmission power value of the most recently transmitted beacon signal stored in a buffer and the notified relative allowable transmission power value.

[0148] Instead of using the method based on the most recently transmitted beacon signal, AP2 may determine the transmission power value using the following method. The beacon signal transmitted by AP2 may include, for example, a transmission parameter identifier as information for identifying the transmission parameters. Examples of transmission parameters that may be considered include the transmission power value, the number of transmitting antennas, and a weighting matrix (such as a steering matrix) for multi-antenna transmission. AP2 may include different transmission parameter identifiers in beacon signals with different transmission parameters. If the beacon signal of AP2 includes a transmission parameter identifier, AP2 retains information about the sets of transmission parameter identifiers and transmission power values ​​of the most recently transmitted beacon signals. AP1 transmits a Multi-AP Trigger signal to AP2 that includes the transmission parameter identifier of AP2's beacon signal related to Measurement. When determining the transmission power, AP2 may determine the transmission power value for coordinated transmission based on the transmission power value of a beacon signal that matches the transmission parameter identifier included in the Multi-AP Trigger signal.

[0149] Furthermore, AP2 may derive a path loss value between AP2 and STA2 from the received power value of a signal including a measurement report received from a destination STA (e.g., STA2) and the transmit power value of the measurement report included in the measurement report. AP2 may calculate an expected RSSI at STA2 based on the transmit power value of AP2 and the path loss value between AP2 and STA2. AP2 may derive a power value of a signal received by STA2 from AP1 in one-way coordination (e.g., an interference signal power value) based on the RSSI of the beacon signal of AP1 measured by STA2 (e.g., the received power value at STA2) included in the measurement report received from STA2 and the transmit power value of AP1 included in the Multi-AP Trigger signal. AP2 may derive (or estimate) the SINR of STA2 based on the expected RSSI value at STA2 and the derived interference signal power value. AP2 may decide to participate in one-way coordination if the SINR of STA2 meets a predetermined quality (e.g., an SINR at which the packet error rate is 10% or less), and may decide not to participate in one-way coordination if the SINR of STA2 does not meet the predetermined quality.

[0150] 18, after a predetermined time (for example, after a Short Inter Frame Space (SIFS)) has elapsed since the Multi-AP Trigger signal was transmitted and received, AP1 transmits a data signal addressed to STA1 using its own transmission power value. If AP2 participates in one-way coordination, it transmits a data signal addressed to STA2 using its own transmission power value. If AP2 does not participate in one-way coordination, it does not transmit a data signal addressed to STA2.

[0151] (Variation 1 of Other Embodiments) The above-described allowable transmission power value, which is a relative value, may be derived, for example, based on the RSSI of a signal other than the beacon signal most recently transmitted by AP2.

[0152] For example, when STA1 receives a signal transmitted from AP2, it transmits a Measurement Report to AP1 including the identifier of the AP (e.g., AP2) that transmitted the received signal, the identifier of the received signal, and the RSSI of the received signal. Fig. 21 shows an example of a Measurement Report including RSSI generated using a specific signal from an OBSS AP (e.g., AP2). The Measurement Report shown in Fig. 21 includes the transmit power value of the Measurement Report by STA200 (STA Tx power subfield), the number of OBSS APs included in the Measurement Report (Number of OBSS AP subfield), and one or more pieces of OBSS information (OBSS Info field). Each piece of OBSS information includes the identifier of the corresponding OBSS AP (AP ID subfield), the identifier of the signal received from the corresponding OBSS AP ("Signal ID" subfield), and the RSSI of the signal received from the corresponding OBSS AP (RSSI subfield).

[0153] The signal identifier may be based on, for example, the type of frame included in the signal (e.g., beacon frame, data frame, etc.). Alternatively, the signal identifier may be based on, for example, the signal type (e.g., NDP, MU PPDU, etc.). Alternatively, the signal identifier may be based on, for example, transmission parameters (e.g., the number of transmit antennas, information on the presence or absence of beamforming, a weighting matrix for multi-antenna transmission (e.g., a steering matrix), a transmission bandwidth, and frequency resource allocation (RU size and allocation type), etc.).

[0154] AP1 may derive the amount of change in AP2's transmission power as AP2's allowable transmission power value based on the RSSI included in the Measurement report received from STA1 (for example, using the RSSI as a reference). AP1 may notify AP2 of a Multi-AP Trigger signal including the allowable transmission power value, which is a relative value, and a signal identifier included in the Measurement report. FIG. 22 shows an example of a Multi-AP Trigger signal including a relative allowable transmission power value for a specific signal. The Multi-AP Trigger signal shown in FIG. 22 includes a Multi-AP Type subfield, a subtype of the Multi-AP cooperative communication method (Multi-AP subtype), and a transmission power value of the Sharing AP during Multi-AP cooperative communication (Sharing AP Tx power subfield) in the Common Info field. The Multi-AP Trigger signal includes user information of one or more Shared APs in the User Info field. The user information of a Shared AP includes an identifier of the corresponding Shared AP (Shared AP ID subfield), an identifier of the signal of the corresponding Shared AP ("Signal ID" subfield), and an acceptable transmission power value of the corresponding Shared AP (Acceptable Tx power subfield).

[0155] When AP2 is notified of a relative allowable transmission power value and a signal identifier by the Multi-AP Trigger signal received from AP1, AP2 may determine its transmission power value based on the transmission power value of a signal stored in the buffer that matches the signal identifier and the relative allowable transmission power value.

[0156] (Variation 2 of Another Embodiment) The above-described allowable transmission power value, which is a relative value, may be notified together with update information of the allowable transmission power value (for example, information on whether or not it has been updated).

[0157] For example, when STA1 receives any signal transmitted from AP2, if the difference (hereinafter also referred to as the amount of change or fluctuation) between the RSSI of the signal currently received from AP2 and the RSSI of a signal previously received from AP2 exceeds a certain amount, STA1 may include the RSSI of the signal currently received from AP2 in a Measurement Report and transmit the same to AP1. On the other hand, for example, if the amount of change in the RSSI of the signal received from AP2 does not exceed a certain amount, STA1 may not need to transmit a Measurement Report to AP1.

[0158] AP1 may derive the amount of change in the transmission power of AP2 as the allowable transmission power value of AP2 based on the RSSI included in the Measurement report received from STA1. AP1 may notify AP2 of a Multi-AP Trigger signal including the allowable transmission power value, which is a relative value, and update information for the allowable transmission power value. For example, if the allowable transmission power value has not been updated, AP1 may not need to notify the allowable transmission power value using the Multi-AP Trigger signal.

[0159] 23 shows an example of a Multi-AP Trigger signal including an allowable transmission power value and update information for the allowable transmission power value. The Multi-AP Trigger signal shown in FIG. 23 includes, in a common information field (Common Info field), a Multi-AP Type subfield, a subtype of the Multi-AP cooperative communication method (Multi-AP subtype), and a transmission power value of the Sharing AP during Multi-AP cooperative communication (Sharing AP Tx power subfield). The Multi-AP Trigger signal also includes, for example, user information for one or more Shared APs in a user information field (User Info field). The user information for the Shared AP includes an identifier of the corresponding Shared AP (Shared AP ID subfield), an identifier of the signal of the corresponding Shared AP (Signal ID subfield), update information for the allowable transmission power value of the corresponding Shared AP ("Update Tx power" subfield), and an allowable interference power value of the corresponding Shared AP (Acceptable Tx power subfield).

[0160] The update information of the allowed transmission power value of the Shared AP (value of the Update Tx power subfield) may be, for example, information indicating whether or not the allowed transmission power value has been changed.

[0161] When the Multi-AP Trigger signal received from AP1 notifies AP2 of the relative value of the allowable transmission power value and that the update information indicates a change in the allowable transmission power value, AP2 may determine its transmission power value based on the transmission power value of the most recent signal stored in the buffer and the relative value of the allowable transmission power value.Also, when the Multi-AP Trigger signal received from AP1 notifies AP2 of the relative value of the allowable transmission power value and that the update information indicates no change in the allowable transmission power value, AP2 may determine its transmission power value based on the transmission power value of the past signal stored in the buffer.

[0162] (Variation 3 of Other Embodiments) The above-described allowable transmission power value of the AP 100 may be notified for each frequency resource.

[0163] For example, STA1 may generate (or measure) a received power value of a beacon signal received from AP2 for each frequency resource, and transmit a Measurement Report including the received power value to AP1. For example, the frequency resource for generating the received power value may be every 20 MHz, every 80 MHz, or every other frequency bandwidth.

[0164] Fig. 24 shows an example of a Measurement report transmitted by STA1. The Measurement report shown in Fig. 24 includes, for example, the bandwidth of the measurement information included in the Measurement report (e.g., "BW" subfield), the frequency resource unit of the measurement information (e.g., "RU unit" subfield), the transmit power value of the Measurement report from STA1 (e.g., "STA Tx power" subfield), the number of OBSS APs included in the Measurement report (e.g., "Number of OBSS AP" subfield), and one or more pieces of OBSS information (OBSS Info field). Each piece of OBSS information includes an identifier of the corresponding OBSS AP (e.g., "AP ID" subfield) and an RSSI (e.g., "RSSI" subfield) for each frequency resource (e.g., RU) of the beacon signal of the corresponding OBSS AP.

[0165] AP1 may determine a transmission power value of the Sharing AP (e.g., AP1) for each frequency resource based on a path loss value derived from the received power value (RSSI) for each frequency resource included in the Measurement report received from STA1 and the transmission power value of the Measurement report included in the Measurement report. AP1 may also determine an allowable transmission power value of the Shared AP (e.g., AP2) for each frequency resource based on the transmission power value for each frequency resource. AP1 may notify AP2 of a Multi-AP Trigger signal including the transmission power value of the Sharing AP for each frequency resource and the allowable transmission power value of the Shared AP for each frequency resource.

[0166] 25 shows an example of a Multi-AP Trigger signal transmitted by AP1. The Multi-AP Trigger signal shown in FIG. 25 includes, for example, a common information field (Common Info field) that includes a Multi-AP cooperative communication method (Multi-AP Type subfield), a subtype of the Multi-AP cooperative communication method (Multi-AP subtype), a bandwidth used in Multi-AP cooperative communication ("BW" subfield), a frequency resource unit of the transmission power value ("RU unit" subfield), and a transmission power value of the Sharing AP for each frequency resource during Multi-AP cooperative communication (Sharing AP Tx power subfield). The Multi-AP Trigger signal also includes, for example, user information of one or more Shared APs in a user information field (User Info field). The user information of the Shared AP includes an identifier of the corresponding Shared AP (Shared AP ID subfield) and an acceptable transmission power value for each frequency resource of the corresponding Shared AP (Acceptable Tx power subfield).

[0167] AP2 may determine the frequency resource from which to transmit a signal and determine the transmission power value of AP2 based on the transmission power value for each frequency resource of AP1 (Sharing AP) included in the Multi-AP Trigger signal received from AP1 and the allowable transmission power value for each frequency resource of AP2 (Shared AP).

[0168] (Variation 4 of Another Embodiment) The Sharing AP may derive the allowable transmission power of the Shared AP based on information about multiple STAs associated with the Sharing AP. If there are multiple destination STAs (subordinate STAs) of the Sharing AP, the Sharing AP (e.g., AP1) may, for example, include in a Multi-AP Trigger signal the minimum allowable transmission power value among the allowable transmission power values ​​derived based on measurement information received from each of the multiple destination STAs as the allowable transmission power value that satisfies a predetermined quality for all of the multiple destination STAs, and notify the Shared AP (e.g., AP2). This allows the Sharing AP to satisfy the predetermined quality for all STAs when performing multi-user transmission to multiple STAs through Multi-AP coordination.

[0169] (Variation 5 of Other Embodiments) When there are multiple Sharing APs, the Shared AP may select the smallest allowable transmission power value from among the allowable transmission power values ​​notified by the Sharing AP and the other Shared APs.

[0170] Fig. 26 shows an example of complex one-way coordination when there are multiple Shared APs. In Fig. 26, AP1 is a Sharing AP and has STA1 under its control. In Fig. 26, AP2 and AP3 are Shared APs and have STA2 and STA3 under their control, respectively. In Fig. 26, AP1, which is a Sharing AP, transmits, for example, a Multi-AP Trigger signal shown in Fig. 27 to AP2 and AP3, which are Shared APs.

[0171] Each Shared AP that receives the Multi-AP Trigger signal derives the transmission power of the Multi-AP coordination signal based on the transmission power of the Sharing AP included in the Multi-AP Trigger signal (e.g., AP Tx power) and the allowable transmission power (e.g., Acceptable Tx power) corresponding to each Shared AP. Furthermore, if user information for another Shared AP is included after the user information for the Shared AP, the Shared AP may derive the allowable transmission power of the other Shared AP. The Shared AP corresponding to the user information following the user information for a certain Shared AP is referred to as the "subsequent Shared AP." For example, in FIGS. 26 and 27 , AP2 derives the allowable transmission power of the subsequent Shared AP (AP3) based on the transmission power of AP2 and the RSSI of the signal received from the subsequent Shared AP (AP3) included in the measurement information received from STA2 under its control. AP2 may notify AP1 and AP3 of a Multi-AP Trigger signal including the transmission power of AP2 and the allowable transmission power of the subsequent Shared AP (AP3).

[0172] FIG. 28 shows an example of a Multi-AP Trigger signal transmitted by a Shared AP (AP2). The Multi-AP Trigger signal shown in FIG. 28 includes, for example, a Multi-AP cooperative communication method (Multi-AP Type subfield), a subtype of the Multi-AP cooperative communication method (Multi-AP subtype subfield), and the transmit power of the Shared AP (AP2) during Multi-AP cooperative communication (e.g., transmit power derived based on the Multi-AP Trigger signal received from the Sharing AP or Shared AP; AP Tx power subfield) in the common information field. The Multi-AP Trigger signal also includes, for example, user information of one or more Shared APs in the user information field. The user information of the Shared AP includes an identifier of the corresponding Shared AP (Shared AP ID subfield) and an allowable transmit power value of the corresponding Shared AP (e.g., the allowable transmit power value of the subsequent Shared AP described above; Accessible Tx power subfield). The allowable transmission power value included in the user information of AP3 in FIG. 27 and the allowable transmission power value included in the user information of AP3 in FIG. 28 may be the same value or different values.

[0173] An AP (AP3 in FIG. 26) that receives a Multi-AP Trigger signal from another Shared AP (AP2 in FIG. 26) derives the transmission power of the Multi-AP coordination signal based on the transmission power of the Shared AP (AP2) included in the Multi-AP Trigger signal (AP Tx power shown in FIG. 28) and the allowable transmission power corresponding to each Shared AP (Acceptable Tx power shown in FIG. 28). The Shared AP (AP3) selects the smallest transmission power from among the multiple transmission powers derived based on the Multi-AP Trigger signals received from the Sharing AP (AP1) and the Shared AP (AP2). As shown in FIG. 26, if the Multi-AP Trigger signal does not include user information of other APs after the user information of the Shared AP, the Shared AP (AP3) transmits a response signal (e.g., an ACK signal) to the Sharing AP (AP1) and the other Shared AP (AP2). After a predetermined time (e.g., after SIFS) has passed since the response signal was transmitted and received, each AP transmits data to its subordinate STAs using the transmission power it derived.

[0174] The Sharing AP may determine the order of the user information of the Shared AP included in the Multi-AP Trigger signal based on the transmission priority order of the Shared AP. Note that the transmission priority of the Shared AP may be determined based on the buffer status notified from the Shared AP or the QoS information of the Shared AP.

[0175] If a Multi-AP Trigger signal received from another Shared AP does not include user information addressed to that AP, the Sharing AP and the Shared AP do not need to derive the transmission power in Multi-AP coordination.

[0176] When a Shared AP receives a Multi-AP Trigger signal containing user information addressed to the Shared AP, the Shared AP may transmit a Multi-AP Trigger signal and a response signal to the Sharing AP and other Shared APs, regardless of whether the transmit power derived based on the Multi-AP Trigger signal satisfies the predetermined quality of the destination STA. For example, if the derived transmit power satisfies the predetermined quality of the destination STA, the Shared AP may transmit a Multi-AP Trigger signal including the transmit power of the Shared AP and the allowable transmit power of the other Shared APs. For example, if the derived transmit power does not satisfy the predetermined quality of the destination STA, the Shared AP may notify "no transmit power" (in other words, the Shared AP does not transmit) in the transmit power information (AP Tx power subfield) of the Shared AP during Multi-AP cooperative communication and notify "no limit" in the allowable transmit power (Accesptable Tx power subfield) of the other Shared APs. When a Shared AP receives an allowable transmission power indicating a certain value from a certain AP and an allowable transmission power indicating "no limit" from another AP, the Shared AP derives the transmission power based on the allowable transmission power indicating a certain value from the certain AP. In other words, in deriving the transmission power, the allowable transmission power indicating a certain value takes priority over the allowable transmission power indicating "no limit."

[0177] If the minimum transmit power selected based on the Multi-AP Trigger signals received from the Sharing AP and the Shared AP does not meet the predetermined quality of the destination STA, the Shared AP may not participate in the Multi-AP coordination. In other words, the Shared AP may not transmit data to the destination STA after a predetermined time has passed since it received or transmitted a response signal transmitted by another Shared AP.

[0178] The above describes variations of other embodiments.

[0179] In the other embodiments, as an example, a case where the subtype of the Multi-AP cooperation type is rough one-way coordination (for example, when a Multi-AP request signal and a Multi-AP response signal are not transmitted or received) has been described as shown in Fig. 18 , but the present invention is not limited to this. For example, as shown in Fig. 7 , the operation according to the other embodiments may be applied when a Multi-AP request signal and a Multi-AP response signal are transmitted or received (for example, exchanged).

[0180] Also, any of variations 1 to 5 may be applied in combination.

[0181] Other embodiments have been described above.

[0182] In the above embodiment, an example of operation in which STA 200 receives a transmission signal from AP 100 and generates measurement information has been described, but STA 200 may also generate measurement information based on a transmission signal from another STA. STA 200 may also determine whether the measurement information is BSS measurement information or OBSS measurement information depending on the BSS to which the other STA belongs. Furthermore, AP 100 may also receive a transmission signal from STA 200 and generate measurement information.

[0183] Furthermore, in the above embodiment, an example of an operation in which the measurement information of which STA 200 should be included in the Multi-AP request signal and the Multi-AP response signal is determined based on the buffer status has been described. However, the parameters used to determine the STA 200 whose measurement information should be included are not limited to the buffer status. For example, Quality of Service (QoS) information may also be used. The QoS information may be notified, for example, by the QoS Characteristics element shown in FIG. 29. The QoS information may be notified, for example, by the Traffic Specification (TSPEC) element shown in FIG. 30. The QoS information may be notified, for example, by the Traffic Classification (TCLAS) element shown in FIG. 31. The QoS information may be notified, for example, by the Intra-Access Category element shown in FIG. 32. As another method for determining the measurement information of which STA 200 should be included in the Multi-AP request signal and the Multi-AP response signal, information on the power save state of the STA 200 may also be used. For example, the AP may determine that the STAs 200 to include in the measurement information should not include STAs 200 in a low power state (e.g., doze state, low power listening mode, etc.), but should include all or some of the STAs 200 in an active state (e.g., active state). The AP may determine the STAs 200 to include in the measurement information based on the priority of data transmission determined using the buffer status, QoS, power saving state, or / and other information of the STAs 200.

[0184] Although the embodiments have been described above with reference to the drawings, the present disclosure is not limited to such examples. It is clear that a person skilled in the art can conceive of various modifications or alterations within the scope of the claims. It is understood that such modifications or alterations also fall within the technical scope of the present disclosure. Furthermore, the components in the embodiments may be combined in any manner without departing from the spirit of the present disclosure.

[0185] In the above-described embodiments, the notation "... part" used for each component may be replaced with other notations such as "... circuit," "... assembly," "... device," "... unit," or "... module."

[0186] The interface names (frame names), field names, or subfield names described in the above-described embodiments may be other names.

[0187] In addition, in each of the above-described embodiments, the field (or subfield) used for notifying control information is an example, and other fields or subfields may be used. Furthermore, the number of bits used for notifying control information in each field or subfield is an example, and other numbers of bits may be used.

[0188] Furthermore, the signal formats described in each of the above-mentioned embodiments are merely examples, and other configurations may be used in which at least one of other fields is added and some fields is deleted, and other configurations may be used in which at least one of other subfields is added and some subfields are deleted in each of the above-mentioned fields.

[0189] Furthermore, in the above embodiment, as an example, a case based on the format defined in IEEE 802.11 has been described, but the format to which an embodiment of the present disclosure is applied is not limited to the IEEE 802.11 format.

[0190] The present disclosure can be realized by software, hardware, or software in conjunction with hardware. Each functional block used in the description of the above embodiments may be partially or entirely realized as an LSI, which is an integrated circuit, and each process described in the above embodiments may be partially or entirely controlled by a single LSI or a combination of LSIs. The LSI may be composed of individual chips, or may be composed of a single chip that includes some or all of the functional blocks. The LSI may have data input and output. Depending on the degree of integration, the LSI may also be called an IC, system LSI, super LSI, or ultra LSI.

[0191] The integrated circuit method is not limited to LSI, and may be realized by a dedicated circuit, a general-purpose processor, or a dedicated processor. Also, a field programmable gate array (FPGA) that can be programmed after LSI manufacturing, or a reconfigurable processor that can reconfigure the connections and settings of circuit cells within the LSI, may be used. The present disclosure may be realized as digital processing or analog processing.

[0192] Furthermore, if an integrated circuit technology that can replace LSI emerges due to advances in semiconductor technology or other derivative technologies, it is natural that such technology may be used to integrate functional blocks. The application of biotechnology, etc. is also a possibility.

[0193] The present disclosure may be implemented in any type of apparatus, device, or system (collectively referred to as a communications apparatus) that has a communications function. The communications apparatus may include a radio transceiver and processing / control circuitry. The radio transceiver may include a receiver and a transmitter, or both functions. The radio transceiver (transmitter and receiver) may include a radio frequency (RF) module and one or more antennas. The RF module may include an amplifier, an RF modulator / demodulator, or the like. Non-limiting examples of communication devices include telephones (e.g., cell phones, smartphones), tablets, personal computers (PCs) (e.g., laptops, desktops, notebooks), cameras (e.g., digital still / video cameras), digital players (e.g., digital audio / video players), wearable devices (e.g., wearable cameras, smartwatches, tracking devices), game consoles, digital book readers, telehealth / telemedicine devices, communication-enabled vehicles or mobile transportation (e.g., cars, airplanes, ships), and combinations of the above devices.

[0194] The communication devices are not limited to portable or mobile devices, but also include any kind of non-portable or fixed equipment, devices, and systems, such as smart home devices (such as home appliances, lighting equipment, smart meters or measuring devices, control panels, etc.), vending machines, and any other "things" that may exist on an IoT (Internet of Things) network.

[0195] Communications include data communications via cellular systems, wireless LAN systems, communication satellite systems, and the like, as well as data communications via combinations of these.

[0196] A communications apparatus also includes devices such as controllers and sensors connected or coupled to a communications device that performs the communications functions described in this disclosure, such as controllers and sensors that generate control and data signals used by the communications device to perform the communications functions of the communications apparatus.

[0197] The communication apparatus also includes infrastructure facilities, such as base stations, access points, and any other apparatus, device, or system that communicates with or controls the various apparatuses listed above, but are not limited to these.

[0198] An access point according to one embodiment of the present disclosure includes a control circuit that determines parameters related to the transmission power of other access points that perform cooperative communication based on measurement information from a terminal, and a communication circuit that transmits a control signal including the parameters to the other access points.

[0199] In one embodiment of the present disclosure, the control signal includes a transmission power value of the access point and the parameter, and the parameter is an upper limit value of the transmission power of the other access point.

[0200] In one embodiment of the present disclosure, the control circuit determines the upper limit value based on a path loss value between the other access point and a terminal under the access point and an allowable interference power of the terminal under the access point.

[0201] In one embodiment of the present disclosure, the measurement information includes a received power value of a signal received by the terminal from the other access point, and the control circuit calculates the path loss value based on the transmission power value of the other access point included in the signal received from the other access point and the received power value.

[0202] In one embodiment of the present disclosure, the measurement information includes a received power value of a signal received by the terminal from the other access point, and the control circuit calculates the parameter indicating the amount of change in the transmission power of the other access point based on the received power value.

[0203] In one embodiment of the present disclosure, the control circuit determines the transmission power of the access point based on a path loss value between the access point and a terminal under the access point and a desired reception quality at the terminal under the access point.

[0204] In one embodiment of the present disclosure, the control circuit calculates the path loss value based on a received power value of a signal received from the terminal and a transmission power value of the measurement information included in the measurement information.

[0205] In one embodiment of the present disclosure, the measurement information includes information identifying a signal from the other access point received by the terminal and a received power value of the signal, the control circuit calculates the parameter based on the received power value, and the communication circuit transmits the control signal including the parameter and information identifying the signal.

[0206] In one embodiment of the present disclosure, the control signal includes information on whether or not the parameter is to be updated.

[0207] In one embodiment of the present disclosure, the parameter is set for each frequency resource in the control signal.

[0208] In one embodiment of the present disclosure, the parameter is an upper limit value of the transmission power of the other access point, and the control signal includes the smallest value among the upper limit values ​​corresponding to each of multiple terminals under the access point.

[0209] In one embodiment of the present disclosure, the control signal is a request signal for participation in the cooperative communication, a response signal to the request signal, or a trigger signal for the cooperative communication.

[0210] An access point according to one embodiment of the present disclosure is an access point that performs cooperative communication and includes a communication circuit that receives a control signal from another access point, the control signal including a parameter related to transmission power determined based on measurement information of a terminal, and a control circuit that controls transmission of a signal based on the parameter.

[0211] In one embodiment of the present disclosure, the communication circuit receives the control signal from a plurality of the other access points, and the control circuit selects the smallest value of the transmission power determined based on parameters included in the control signal from each of the plurality of other access points.

[0212] In a communication method according to one embodiment of the present disclosure, an access point determines parameters related to the transmission power of other access points that perform cooperative communication based on measurement information from a terminal, and transmits a control signal including the parameters to the other access points.

[0213] In a communication method according to one embodiment of the present disclosure, an access point performing cooperative communication receives a control signal from another access point, the control signal including a parameter related to transmission power determined based on measurement information of a terminal, and controls the transmission of a signal based on the parameter.

[0214] The disclosures of the specification, drawings and abstract contained in Japanese Patent Application No. 2024-070896, filed on April 24, 2024, are incorporated herein by reference in their entirety.

[0215] One embodiment of the present disclosure is useful in wireless communication systems.

[0216] 100 AP 101, 201 Radio receiving unit 102, 202 Preamble demodulation unit 103, 203 Data demodulation unit 104, 204 Data decoding unit 105 Measurement information storage unit 106 Buffer status information storage unit 107 Capability information storage unit 108 Scheduling unit 109 Data generation unit 110 Data encoding unit 111 Data modulation unit 112 Preamble generation unit 113, 208 Radio transmission unit 151 BSS measurement information storage unit 152 OBSS measurement information storage unit 200 STA 205 Measurement control unit 206 Buffer status control unit 207 Transmission signal generation unit 251 BSS measurement information unit 252 OBSS measurement information unit

Claims

1. An access point comprising: a control circuit that determines parameters related to the transmission power of other access points that perform cooperative communication based on measurement information from a terminal; and a communication circuit that transmits a control signal including the parameters to the other access points.

2. The access point according to claim 1, wherein the control signal includes a transmission power value of the access point and the parameter, and the parameter is an upper limit value of the transmission power of the other access point.

3. The access point according to claim 2, wherein the control circuit determines the upper limit value based on a path loss value between the other access point and a terminal under the control of the access point, and an allowable interference power of the terminal under the control of the access point.

4. The access point according to claim 3, wherein the measurement information includes a received power value of a signal received by the terminal from the other access point, and the control circuit calculates the path loss value based on the transmission power value of the other access point included in the signal received from the other access point and the received power value.

5. The access point according to claim 2, wherein the measurement information includes a received power value of a signal received by the terminal from the other access point, and the control circuit calculates the parameter indicating the amount of change in transmission power of the other access point based on the received power value.

6. The access point according to claim 2, wherein the control circuit determines the transmission power of the access point based on a path loss value between the access point and a terminal under the control of the access point and a desired reception quality at the terminal under the control of the access point.

7. The access point according to claim 6, wherein the control circuit calculates the path loss value based on a received power value of a signal received from the terminal and a transmission power value of the measurement information included in the measurement information.

8. The access point according to claim 1, wherein the measurement information includes information identifying a signal received by the terminal from the other access point and a received power value of the signal, the control circuit calculates the parameter based on the received power value, and the communication circuit transmits the control signal including the parameter and information identifying the signal.

9. The access point according to claim 1, wherein the control signal includes information on whether or not the parameter has been updated.

10. The access point according to claim 1, wherein in the control signal, the parameter is set for each frequency resource.

11. The access point according to claim 1, wherein the parameter is an upper limit value of the transmission power of the other access point, and the control signal includes the smallest value of the upper limit values ​​corresponding to each of a plurality of terminals under the control of the access point.

12. The access point according to claim 1, wherein the control signal is a request signal for participation in the cooperative communication, a response signal to the request signal, or a trigger signal for the cooperative communication.

13. An access point that performs cooperative communication, comprising: a communication circuit that receives a control signal from another access point, the control signal including a parameter related to transmission power determined based on measurement information from a terminal; and a control circuit that controls the transmission of signals based on the parameter.

14. The access point according to claim 13, wherein the communication circuit receives the control signals from a plurality of the other access points, and the control circuit selects the minimum value of the transmission powers determined based on parameters included in the control signals from each of the plurality of other access points.

15. A communication method, in which an access point determines parameters related to the transmission power of other access points that will perform cooperative communication based on measurement information from terminals, and transmits a control signal including the parameters to the other access points.

16. A communication method in which an access point performing cooperative communication receives a control signal from another access point, the control signal including a parameter related to transmission power determined based on measurement information from a terminal, and controls signal transmission based on the parameter.

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