WO2025225274A1 - Access point and communication method - Google Patents

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

This disclosure relates to an access point and a communication method.

The Study Group (SG) is currently developing the technical specifications for IEEE 802.11bn (hereinafter referred to as "11bn") as the successor to the Institute of Electrical and Electronics Engineers (IEEE) 802.11 standard, IEEE 802.11be (hereinafter referred to as "11be"). 11be is also known as "Extremely High Throughput (EHT)." 11bn is also known as "Ultra High Reliability (UHR)."

IEEE 802.11-23/0079r10, IEEE 802.11 UHR Proposed CSD IEEE 802.11-23/1871r2, M-AP Coordination Transmission framework IEEE 802.11-20/0410r4, Coordinated Spatial Reuse Procedure

However, methods for controlling signal transmission in wireless communications such as wireless LAN have not been fully explored.

Non-limiting examples 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 communications.

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 are performing cooperative communication based on measurement information from terminals, and a communication circuit that transmits control signals including the parameters to the other access points.

Note that these comprehensive or specific aspects may be realized as a system, device, method, integrated circuit, computer program, or recording medium, or as any combination of a system, device, method, integrated circuit, computer program, and recording medium.

According to one embodiment of the present disclosure, it is possible to improve the efficiency of transmission control in wireless communications, for example.

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 of the embodiments and features described in the specification and drawings, but not all of them necessarily need to be provided to obtain one or more identical features.

Diagram showing an example of a Multi-Access Point (Multi-AP) coordination sequence Block diagram showing an example of the configuration of part of an AP (Access Point) Block diagram showing an example of the configuration of a part of a terminal (STA: Station) FIG. 10 shows an example of a transmission and reception sequence between an AP and a STA. Block diagram showing an example of an AP configuration Block diagram showing an example of STA configuration Diagram showing an example of Multi-AP coordination in action Diagram showing an example of the configuration of a Basic Service Set (BSS) Diagram showing an example of a Multi-AP request signal A diagram showing an example of measurement information included in a Multi-AP request Diagram showing an example of a Multi-AP response signal A diagram showing an example of measurement information included in a Multi-AP response A diagram showing an example of optimal coordination A diagram showing an example of rough one-way coordination A diagram showing an example of complex one-way coordination Diagram showing an example of sending a Multi-AP response signal A diagram showing an example of measurement information included in a Multi-AP response A diagram showing an example of a transmission sequence for rough one-way coordination An example of a measurement report An example of a Multi-AP Trigger frame An example of a measurement report An example of a Multi-AP Trigger frame An example of a Multi-AP Trigger frame An example of a measurement report An example of a Multi-AP Trigger frame A diagram showing an example of complex one-way coordination An example of a Multi-AP Trigger frame An example of a Multi-AP Trigger frame A diagram showing an example of a Quality of Service (QoS) Characteristics element A diagram showing an example of a Traffic Specification (TSPEC) element A diagram showing an example of a Traffic Classification (TCLAS) element A diagram showing an example of an Intra Access Category element

Each embodiment of the present disclosure will be described in detail below with reference to the drawings.

In 11bn, Multi-AP (MAP) coordination (also known as 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).

Multi-AP coordination includes types (or schemes) of multi-AP coordination such as "Joint Transmission (JT)", in which multiple APs transmit the same data; "Coordinated Beamforming (C-BF)", which reduces interference to destination STAs of other APs through null control; "Coordinated Spatial Reuse (C-SR)", which reduces interference to destination STAs of other APs through transmit power control; "Coordinated Time Division Multiple Access (C-TDMA)", which divides and shares time resources; "Coordinated Orthogonal Frequency Division Multiple Access (C-OFDMA)", which divides and shares frequency resources; and "Coordinated Restricted Target Wake Time (C-rTWT)", which coordinates the transmission period of signals that require low latency. Multi-AP coordination involves considering a Multi-AP coordination sequence that allows APs to exchange information with other APs or terminals (STAs: Stations or non-AP Stations, hereafter referred to as "STAs") for the purpose of coordination (see, for example, non-patent documents 2 and 3).

Figure 1 shows an example of a Multi-AP coordination sequence. As shown in Figure 1, the Multi-AP coordination sequence includes the following phases:

<Cooperative AP search 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 for 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 for multi-AP coordination. For example, an AP may actively discover other APs that support multi-AP coordination by transmitting a signal requesting a capability for multi-AP coordination (e.g., a probe request signal containing a multi-AP information element) to a specific AP. 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 replaced with an AP MLD and the STA with a non-AP MLD. Alternatively, the AP and STA may be APs and STAs, respectively, that are affiliated with an MLD.

<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, the STA stores 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 in a buffer. 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 a STA or AP receiving a transmission signal from another STA or AP may be performed during the measurement information collection phase or before the measurement information collection phase. Also, a STA may select a transmission signal from another AP related to the derivation of measurement information based on information about the other AP notified by the AP to which the STA belongs.

<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."

<Cooperative 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.

The above explains an example of a Multi-AP coordination sequence.

However, methods for controlling the multi-AP coordination sequence (for example, methods for exchanging measurement information used in multi-AP coordination) have not been fully considered.

A non-limiting embodiment of the present disclosure describes a method for appropriately controlling multi-AP coordination among multiple APs and improving the efficiency of multi-AP coordination.

For example, in one embodiment of the present disclosure, the AP holds measurement information from the STA and, based on the measurement information, determines whether to send or receive a signal related to Multi-AP coordination that includes the measurement information (for example, a Multi-AP request or Multi-AP response, as described below). 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 becomes able to send and receive signals in coordination with other APs using Multi-AP coordination.

[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 a 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. The STA 200 transmits an uplink (UL) signal based on a signal received from the AP 100.

FIG. 2 is a block diagram showing an example configuration of a portion of an AP 100 according to one embodiment of the present disclosure. In the AP 100 shown 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.

FIG. 3 is a block diagram showing an example configuration of a portion of STA200 according to one embodiment of the present disclosure. In STA200 shown 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 transmitting circuit) transmits or receives control information or data in cooperative communication.

In this embodiment, multiple APs 100 and multiple STAs 200 perform Multi-AP coordination. As an example, we will explain a method in which two APs 100 (e.g., AP1 and AP2) send and receive information about Multi-AP coordination with two STAs 200 (e.g., STA1 and STA2) and transmit Multi-AP coordination signals.

Below, an example of the operation of the AP 100 and STA 200 according to this embodiment will be described.

FIG. 4 is a sequence diagram showing an example of the operation of AP100 and STA200 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)) consisting of AP1 and STA1, and BSS2, which is consisting of AP2 and STA2.

In Figure 4, AP1 broadcasts a signal including a capability related to Multi-AP coordination (for example, referred to as "Multi-AP coordination capability"). The signal including the Multi-AP coordination capability may be, for example, a Beacon signal or some other signal. AP2 receives and processes the Beacon signal transmitted from AP1, and, by referring to the Multi-AP coordination capability, stores information regarding AP1's support for Multi-AP coordination (for example, capability information) in a buffer.

STA1 also receives a beacon signal from AP1, to which it belongs, measures the received power based on the received beacon signal, and stores the measurement results (e.g., BSS measurement information) in a buffer. STA2 also receives a beacon signal from AP1, which is in an overlapping BSS (OBSS), and 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 results (e.g., OBSS measurement information) in a buffer.

Similarly, in Figure 4, AP2 broadcasts a signal (e.g., a Beacon signal) that includes the Multi-AP coordination capability. AP1 receives and processes 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.

STA1 also 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 results (e.g., OBSS measurement information) in a buffer. STA2 also 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 results (e.g., BSS measurement information) in a buffer.

AP1 sends a Measurement report poll signal to STA1 requesting that STA1 send its measurement information (called Measurement information or Measurement report). When STA1 receives the Measurement report poll signal, it generates a Measurement report containing measurement information (e.g., the received power of the transmission signal from AP1 and the interference power from the transmission signal from AP2) and sends the Measurement report to AP1. AP1 receives the measurement information from STA1.

Similarly, AP2 sends a Measurement report poll signal to STA2 requesting that STA2 send its measurement information. 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 sends the Measurement report to AP2. AP2 receives the measurement information from STA2.

When AP1 acquires the TXOP, it controls Multi-AP coordination as the Sharing AP. For example, based on the Measurement report received from STA1, AP1 sends a signal (referred to as a "Multi-AP request signal" or "MAP request signal") containing information requesting whether or not to participate in the Multi-AP coordination controlled by AP1 to AP2, which supports Multi-AP coordination.

AP2 performs a receiving process for 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 transmits, to AP1, a signal (referred to as a "Multi-AP response signal" or a "MAP response signal" for example) 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 the coordination, AP2 is controlled by the Sharing AP as a Sheared AP.

AP1 performs reception processing of the Multi-AP response signal. For example, AP1 refers to the response information included in the Multi-AP response signal indicating whether or not AP1 can participate in Multi-AP coordination, and performs scheduling processing for AP1 and AP2 in Multi-AP coordination (including, for example, determining the Multi-AP coordination type and resource information). AP1 transmits the scheduling information determined by the scheduling processing (for example, "Multi-AP coordination scheduling information") to AP2. The Multi-AP coordination scheduling information may be transmitted, for example, by a Trigger frame.

AP1 also transmits a Multi-AP coordination signal to STA1 in accordance with the determined scheduling information for AP1.

AP2 receives the Multi-AP coordination scheduling information sent from AP1. For example, AP2 sends a Multi-AP coordination signal to STA2 in accordance with the scheduling information for AP2.

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 detection result of the DL signal.

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

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

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 the scheduling information for each destination STA (e.g., 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.

Furthermore, Multi-AP coordination scheduling may include determining the transmission timing of Multi-AP coordination. For example, AP1 and AP2 may transmit Multi-AP coordination signals simultaneously or at different times. Multi-AP coordination scheduling may include the transmission power of Multi-AP coordination. For example, AP1 may notify AP2 of its transmission power in Multi-AP scheduling, and AP2 may transmit the Multi-AP coordination signal at the transmission power notified in Multi-AP scheduling. Further, Multi-AP coordination scheduling may include parameters related to the transmission power of Multi-AP coordination. For example, AP1 may include parameters for AP2 to determine the transmission power in Multi-AP scheduling, and AP2 may derive the transmission power of AP2's Multi-AP coordination signal based on the parameters related to the transmission power notified in Multi-AP scheduling, and transmit the Multi-AP coordination signal.

The above explains an example of a Multi-AP coordination sequence.

[Configuration example of AP100]
FIG. 5 is a block diagram showing an example of the configuration of an AP 100 (corresponding to, for example, a downlink radio transmitting device) according to this embodiment.

The AP 100 shown in FIG. 5 may include, for example, a radio receiving unit 101, a preamble demodulating unit 102, a data demodulating 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 generating unit 109, a data encoding unit 110, a data modulating unit 111, a preamble generating unit 112, and a radio transmitting unit 113.

Note that 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. Also, at least one of the wireless reception unit 101 and wireless transmission unit 113 shown in FIG. 5 may be included in the communication unit shown in FIG. 2.

In FIG. 5, 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. 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 preamble demodulation unit 102 and the data signal to data demodulation unit 103.

The preamble demodulation unit 102 performs a Fourier transform (e.g., Fast Fourier Transform (FFT)) on the preamble signal input from the radio reception unit 101, and extracts reception control information used for demodulating and decoding the data signal. The reception control information may include, for example, frequency bandwidth (BW), Modulation and Coding Scheme (MCS), and error correction code. The preamble demodulation unit 102 also performs channel estimation based on a reference signal included in the preamble signal, and derives a channel estimation value. The preamble demodulation unit 102 outputs the reception control information to the data demodulation unit 103 and data decoding unit 104, and outputs the channel estimation value to the data demodulation unit 103.

The data demodulation unit 103 performs an FFT on the data signal input from the radio reception unit 101, and demodulates the data signal using the reception control information and channel estimation value input from the preamble demodulation unit 102. The data demodulation unit 103 outputs the demodulated data signal to the data decoding unit 104.

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, buffer status information holding unit 106, capability information holding unit 107, and scheduling unit 108.

The measurement information holding unit 105 holds in a buffer the measurement information received from other APs 100 or STAs 200 and contained 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 that are 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 that are 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 was transmitted from an AP 100 or STA 200 that belongs 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 STAs 200 within the BSS in the BSS measurement information holding unit 151. Furthermore, the measurement information holding unit 105 holds the measurement information contained in the decoded data signals of the AP 100 and STA 200 within the OBSS in the OBSS measurement information holding unit 152. During scheduling, the measurement information holding unit 105 outputs the held measurement information from the BSS measurement information holding unit 151 and the BSS measurement information holding unit 152 to the scheduling unit 108.

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.

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

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 signals to other APs or STAs 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, data encoding unit 110, data modulation unit 111, and preamble generation unit 112.

The data generation unit 109 generates a data series to be transmitted to other APs or STA200 based on the scheduling information input from the scheduling unit 108. For example, the data series to be transmitted to other APs 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 series to be transmitted to STA200 may include a signal requesting the 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 the 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.

The data encoding unit 110 encodes the data sequence input from the data generation unit 109 based on the scheduling information input from the scheduling unit 108, and outputs the encoded data to the data modulation unit 111.

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.

The preamble generation unit 112 generates a preamble signal based on the scheduling information input from the scheduling unit 108. The preamble generation unit 112 performs modulation and IFFT processing on the preamble signal, and outputs the preamble signal to the radio transmission unit 113.

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

[STA200 configuration example]
FIG. 6 is a block diagram showing an example of the configuration of the STA 200 (for example, a downstream radio receiving device).

The STA 200 shown in FIG. 6 may include, for example, a radio receiver 201, a preamble demodulator 202, a data demodulator 203, a data decoder 204, a measurement controller 205, a buffer status controller 206, a transmission signal generator 207, and a radio transmitter 208.

Note that 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 FIG. 6 may be included in the control unit shown in FIG. 3, and at least one of the wireless receiving unit 201 and wireless transmitting unit 208 shown in FIG. 6 may be included in the communication unit shown in FIG. 3.

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

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 the 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, data decoding unit 204, and measurement control unit 205, and outputs the channel estimation value to the data demodulation unit 203.

The data demodulation unit 203 performs an FFT on the data signal input from the radio reception 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.

The data decoding unit 204 uses the reception control information input from the preamble demodulation unit 202 to decode the demodulated data signal input from the data demodulation unit 203. The data decoding unit 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, the data decoding unit 204 outputs the decoded data signal to the measurement control unit 205, buffer status control unit 206, and transmission signal generation unit 207.

The measurement control unit 205 may include, for example, a BSS measurement information unit 251 that calculates measurement information based on signals received from AP100 and STA200 of the BSS to which STA200 belongs, and an OBSS measurement information unit 252 that calculates measurement information based on signals received from AP100 and STA200 of a BSS to which STA200 does not belong.The measurement control unit 205 determines whether the received signal was transmitted from AP100 or STA200 belonging to a BSS or an OBSS, 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 signals transmitted from AP100 and STA200 in a 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 it in a buffer. Also, in the case of signals transmitted from AP100 and STA200 in an OBSS, the measurement control unit 205 calculates measurement information (e.g., CSI or interference power) in the OBSS measurement information unit 252 and stores it in a buffer. Also, the measurement control unit 205 may use the measurement information calculated in the BSS measurement information unit 251 and OBSS measurement information unit 252 to calculate measurement information such as SINR or ARIL and store it in a buffer. The measurement control unit 205 may associate each piece of measurement information calculated in the BSS measurement information unit 251 and the OBSS measurement information unit 252 with the signal identifier of the received signal for which the measurement information was calculated, and store it in a buffer. The measurement control unit 205 may also calculate measurement information for each frequency resource in the BSS measurement information unit 251 and the OBSS measurement information unit 252. When the measurement control unit 205 receives a request to transmit measurement information in the decoded data signal input from the data decoding unit 204 (for example, when the decoded data signal is a BFRP signal), it outputs the measurement information stored in the buffer to the transmission signal generation unit 207.

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.

The transmission signal generation unit 207 generates a data series to be transmitted to AP100 based on the decoded data signal input from the data decoding unit 204. For example, the data series to be transmitted to AP100 may include a response signal (ACK or Block ACK (BA)) to the signal received from AP100. Furthermore, if the decoded data signal input from the data decoding unit 204 includes a signal requesting the transmission of measurement information (e.g., a BFRP signal), the transmission signal generation unit 207 may include measurement information in the data series to be transmitted to AP100. Furthermore, if the decoded data signal input from the data decoding unit 204 includes a signal requesting the 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 series to be transmitted to AP100. The transmission signal generation unit 207 encodes the generated data series and generates a data signal by performing modulation and IFFT processing on a specified frequency resource. The transmission signal generation unit 207 adds a preamble signal to the data signal to generate a wireless frame, and outputs it to the wireless transmission unit 208.

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

The above explains example configurations of AP100 and STA200.

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

For example, in one embodiment of the present disclosure, AP 100 exchanges measurement information using information requesting participation in Multi-AP coordination (Multi-AP request signal) and information responding to participation in Multi-AP coordination (Multi-AP response signal).

For example, in the measurement information collection phase, AP100 does not send measurement information to other APs or receive measurement information from other APs, but in the cooperative negotiation phase, APs send and receive Multi-AP request signals containing measurement information and Multi-AP response signals containing measurement information. For example, AP100 may send 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, AP100 may receive measurement information contained in Multi-AP request signals from other APs and send measurement information contained in Multi-AP response signals to other APs.

Figure 7 shows an example of the operation of AP100 and STA200. The example in Figure 7 shows an example of the operation of BSS1, which is composed of AP1 and STA1 belonging to AP1, and BSS2, which is composed of AP2 and STA2 belonging to AP2, as shown in Figure 8. The arrows in Figure 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.

In Figure 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 for the path in Figure 8a) using the beacon signal from AP1, and generates OBSS measurement information (e.g., measurement information for the path in Figure 8d) using the beacon signal from AP2. Similarly, for example, STA2 generates BSS measurement information (e.g., measurement information for the path in Figure 8b) using the beacon signal from AP2, and generates OBSS measurement information (e.g., measurement information for the path in Figure 8c) using the beacon signal from AP1.

In addition, AP100 may notify its subordinate STA200 of the APs that will measure measurement information. For example, AP100 may notify its subordinate STA200 that it will acquire measurement information from signals transmitted by APs that support multi-AP coordination (in other words, have the capability for multi-AP coordination). Whether or not to measure measurement information for each AP may be determined depending on whether or not the AP belongs to a common multi-AP coordination group (called an AP candidate set or virtual BSS). For example, AP100 may notify STA200 of the APs that will measure measurement information by transmitting a beacon signal to STA200 that includes identifiers of all APs that belong to the multi-AP coordination group (called a multi-AP coordination group list). In other words, AP100 may notify STA200 that it will not measure measurement information for APs that are not included in the multi-AP coordination group list. In addition, whether or not to measure measurement information may be notified depending on whether or not the AP has the same coordination group ID as the AP to which it belongs. For example, AP100 transmits a beacon signal including the ID of the coordination group to which AP100 belongs. STA200 receives the beacon signal and determines the coordination group ID of AP100 to which STA200 belongs. If the coordination group ID included in a signal received from another AP is the same as the coordination group ID of AP100 to which STA200 belongs, STA200 measures measurement information; if it is different from the coordination group ID of AP100 to which STA200 belongs, STA200 does not measure the measurement information.

7, AP1 sends a Measurement report poll signal to STA1, and AP2 sends a Measurement report poll signal to STA2. When STA1 receives a Measurement report poll signal from AP1, it includes measurement information (e.g., path loss values) of paths a) and d) shown in FIG. 8 in a Measurement report and sends it to AP1. When STA2 receives a Measurement report poll signal from AP2, it includes measurement information (e.g., path loss values) of paths b) and c) shown in FIG. 8 in a Measurement report and sends it to AP2. 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 by a Measurement report poll signal that it will include the received power value of each beacon signal in the Measurement report and send it. At this time, the AP 100 may derive the 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. Below, an example is described in which, during the measurement information collection phase, the STA derives measurement information based on the received power value and interference power value obtained using a beacon signal. 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.

In Figure 7, for example, AP1 becomes the Sharing AP and manages Multi-AP coordination. In this case, AP1 notifies AP2 whether or not it will participate in Multi-AP coordination by sending a Multi-AP request signal including measurement information. The measurement information included in the Multi-AP request signal may include, for example, the 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 the signal received by STA1 from its own AP (AP1) or the received power value of the signal received by STA1 from its own AP (AP1) in cooperative transmission (which can be derived from the transmission power value and path loss value of the signal transmitted by its own AP (AP1) in cooperative transmission), and the signal error rate of the received signal. For example, STA1 may derive an ARIL value based on an SINR value that results in STA1's packet error rate being 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 cooperative transmission, and the STAs may derive the ARIL value for 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 an SINR value that results in STA1's packet error rate being 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.

In Figure 7, AP2 transmits to AP1 a Multi-AP response signal containing information indicating whether or not it will participate in Multi-AP coordination. If AP2 will participate in Multi-AP coordination, the Multi-AP response signal may contain measurement information. The measurement information contained in the Multi-AP response signal may include the path loss value between the Shared AP (AP2) and the destination STA (STA2) of the Shared AP (AP2), the path loss value between the Sharing AP (AP1) and the destination STA (STA2) of the Shared AP (AP2), and the ARIL value of the destination STA (STA2) of the Shared AP (AP2).

In Figure 7, AP1, the Sharing AP, performs scheduling based on the 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, the Sharing AP, and AP2, the Shared AP, transmit data to their subordinate STAs 1 and 2 using Multi-AP coordination based on the scheduling information contained in the Multi-AP Trigger signal.

Note that in the example of Figure 7, one Sharing AP and one Shared AP send and receive Multi-AP request signals and Multi-AP response signals, but there may be multiple Shared APs, and the Multi-AP request signal may be a signal sent to multiple Shared APs.

<Example of a Multi-AP request signal>
FIG. 9 shows an example of a Multi-AP request signal.

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

The "Number of Shared APs" subfield, for example, communicates information about the number of Shared APs that are the destination of the Multi-AP request signal. The "Shared AP ID" subfield communicates information about the identifiers (AP IDs) of the Shared APs, a number equal to the number of Shared APs communicated by the Number of Shared APs subfield.

The "Measurement Info" subfield, for example, notifies measurement information (e.g., path loss value, ARIL) about the STA belonging to the Sharing AP (the destination STA of the Sharing AP).

Figure 10 shows an example of the Measurement Info subfield included in a Multi-AP request signal.

In Figure 10, the "Number of STAs" subfield notifies information about the number of destination STAs of the Sharing AP.

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

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

In Figure 11, the "MAP type response" subfield indicates whether or not the device can participate in communications of the Multi-AP coordination type, as notified by the Multi-AP request signal.

The "Measurement Info" subfield, for example, notifies measurement information (e.g., path loss value, ARIL) about the STA belonging to the Shared AP (the destination STA of the Shared AP).

Figure 12 shows an example of the Measurement Info subfield included in a Multi-AP response signal.

In Figure 12, the "Number of STAs" subfield provides information about the number of STAs that are destinations of the Shared AP.

The "STA Info" subfield contains, for example, a number equal to the number of STAs notified in the Number of STA subfield. The STA Info subfield contains, for example, a "STA ID" subfield that notifies the identifier for each STA, an "ARIL" subfield that notifies the ARIL value for each STA, and a "Pathloss" subfield that notifies the path loss value between the STA and the Sharing AP.

The above explains examples of Multi-AP request signals and Multi-AP response signals.

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 the 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 the buffer status information received by the Shared AP from the STA.

In this embodiment, the AP 100 determines the control information to be transmitted and received between multiple APs performing multi-AP cooperative communication (multi-AP coordination) based on the measurement information of the STAs 200, and transmits or receives the determined control information. For example, measurement information of the APs 100 and 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 STAs 200 not related to multi-AP cooperative communication does not need to be transmitted and received (or exchanged). This means that, for example, in the measurement information collection phase, measurement information of all APs 100 and 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 in wireless communication (e.g., multi-AP coordination).

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

For example, when C-SR is notified by the Request MAP type subfield of the Multi-AP request signal shown in Figure 9, the Multi-AP subtype subfield may notify one of optimal coordination, rough one-way coordination, or 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."

Figure 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 Figure 13) collects measurement information from its subordinate STAs and aggregates it to a Sharing AP (AP1 in the example of Figure 13), which then determines the transmit power of each AP so as to reduce residual interference for 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 transmit power of each Shared AP determined by the Sharing AP is notified to the Shared AP by including it in the scheduling information of the Multi-Ap Trigger signal.

Figure 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 the Shared AP (AP2 in the example of Figure 14) determines the transmit power of the Sharing AP (AP1 in the example of Figure 14) so as to reduce residual interference to the destination STA of the Sharing AP. In Rough one-way coordination, the Sharing AP determines the transmit power of the Sharing AP without using the measurement information of the Shared AP. The Shared AP determines the transmit 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 Sharing AP's destination STA and the path loss value between the Sharing AP's destination STA 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 and the path loss value between the Sharing AP's destination STA and the Shared AP notified in the Multi-AP request signal. 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 it in the Multi-AP request signal. 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 transmission power of that Shared AP without using measurement information from the other Shared APs. For example, a Shared AP determines the transmission power that reduces residual interference to the Sharing AP's destination STA, and does not need to consider the interference it may cause to the destination STAs of the other Shared APs.

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 Sharing AP's destination STA 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 the measurement information of the Shared AP. Also, the Shared AP determines the transmission power of the Shared AP based on the measurement information notified by the Sharing AP and the measurement information received from other Shared APs. For example, a Multi-AP request signal in which C-SR is indicated in the Request MAP type subfield and complex one-way coordination is indicated in the Multi-AP subtype subfield may include a measurement Info subfield containing the ARIL of the Sharing AP's destination STA and the path loss value between the Sharing AP's destination STA and each Shared AP.

Variation 1 allows measurement information used (or referenced) in the applied Multi-AP coordination method type and subtype of the Multi-AP coordination type to be notified by the Multi-AP request signal, and measurement information not used in the Multi-AP coordination method type and subtype of the Multi-AP coordination type is not notified. This reduces the overhead of the Multi-AP request signal.

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

For example, if a Shared AP receives a Multi-AP request signal in which C-SR is indicated in the Request MAP type subfield and Optimal coordination is indicated in the Multi-AP subtype subfield, and the Shared AP wishes to participate in C-SR optimal coordination, the Shared AP will send a Multi-AP response signal to the Sharing AP that includes, 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.

Furthermore, for example, if a Shared AP receives a Multi-AP request signal in which C-SR is indicated in the Request MAP type subfield and rough one-way coordination is indicated in the Multi-AP subtype subfield, and the Shared AP participates in the C-SR rough one-way coordination, the Shared AP does not need to include the measurement Info subfield in the Multi-AP response signal.

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, if the Shared AP wishes to participate in the complex one-way coordination of C-SR, it may transmit a Multi-AP response signal to the Sharing AP and other Shared APs that includes in the measurement Info subfield the ARIL of the Shared AP's destination STA and the path loss value between the Shared AP's destination STA and the other Shared APs.

Figure 16 shows an example of transmitting a Multi-AP response signal in complex one-way coordination. In Figure 16, Shared APs (AP2, AP3) transmit Multi-AP response signals to the 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 by using a Multi-AP request signal. For example, the order in which the Multi-AP response signals are transmitted may be notified by the order of the Sharing AP ID subfields in the Multi-AP request signal. Figure 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 Figure 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).

Variation 2 uses the Multi-AP response signal to notify 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, and does not notify 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. This reduces the overhead of the Multi-AP response signal.

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

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

Furthermore, 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).

Variation 3 allows the Sharing AP to determine the type of Multi-AP cooperation method using only the measurement information of the STA200 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 the STA200 under the Shared AP. This reduces the overhead of the measurement information used to determine the type of Multi-AP cooperation method.

[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.

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.

[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 .

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 this in measurement information.

The transmission power value of AP100 notified in the measurement information may be, for example, information notifying the recommended minimum transmission power value of AP100 to which STA200 belongs. When AP100 receives measurement information including the recommended minimum transmission power from a subordinate STA200, it may transmit a signal to STA200 at the recommended minimum transmission power, or it may determine a transmission power equal to or greater than the recommended minimum transmission power based on the recommended minimum transmission power and transmit a signal to STA200.

Furthermore, the transmission power value of AP100 notified in the measurement information may be, for example, information notifying the recommended maximum transmission power value of another AP100 to which STA200 does not belong. When AP100 receives measurement information including a recommended maximum transmission power value from a subordinate STA200, it may notify the other AP100 by including the recommended maximum transmission power value received from STA200 in the measurement information of a Multi-AP request signal or a Multi-AP response signal. The other AP100 may transmit a signal to the other STA200 using the recommended maximum transmission power notified in the measurement information, or may determine a transmission power below the recommended maximum transmission power based on the recommended maximum transmission power and transmit a signal to the other STA200.

The measurement information that STA200 transmits to AP100 may include both the recommended minimum transmission power value of AP100 and the maximum transmission power of another AP100, or it may include transmission power information for either one of them.

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

[Variation 6]
Whether to transmit or 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.

For example, if the Sharing AP decides to cooperatively transmit C-SR using optimal coordination based on measurement information, it may decide to send and receive a Multi-AP request signal and a Multi-AP response signal. In this case, the Sharing AP sends a Multi-AP request signal to the Shared AP, and the Shared AP that receives the Multi-AP request signal sends a Multi-AP response signal to the Sharing AP.

Furthermore, for example, if the Sharing AP decides to cooperatively transmit a C-SR using rough one-way coordination based on the measurement information, it may decide not to send or receive a Multi-AP request signal or a Multi-AP response signal. In this case, the Sharing AP may omit sending the Multi-AP request signal, and the Shared AP may omit sending the Multi-AP response signal. Figure 18 shows an example of a transmission sequence when the subtype of the Multi-AP coordination type (C-SR) is rough one-way coordination. When cooperatively transmitting using rough one-way coordination, the Sharing AP may omit sending the Multi-AP request signal and receiving the Multi-AP response signal, and notify the measurement information (measurement Info) using a MAP Trigger signal. The measurement information 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.

Furthermore, for example, if the Sharing AP decides to coordinate the transmission of C-SR using complex one-way coordination based on measurement information, it may decide to send and receive a Multi-AP request signal and a Multi-AP response signal. In this case, the Sharing AP sends a Multi-AP request signal to the Shared AP, and the Shared AP that receives the Multi-AP request signal sends a Multi-AP response signal to the Sharing AP and other Shared APs.

Variation 6 determines whether to send 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.

The above describes one embodiment of the present disclosure.

(Other embodiments)
In another embodiment, the AP 100 notifies or exchanges the allowable transmission power value (information on the transmission power of the other AP) 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.

For example, during the measurement information collection phase, AP 100 does not send measurement information to other APs or receive measurement information from other APs, but during the cooperative negotiation phase, APs send and receive Multi-AP request signals including allowable transmission power values, Multi-AP response signals including allowable transmission power values, or Multi-AP Trigger signals including allowable transmission power values.

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.

AP100 may determine the allowable transmission power value of other APs performing multi-AP cooperative communication, for example, based on a measurement report from STA200.

For example, when the subtype of the multi-AP coordination type (e.g., C-SR) is rough one-way coordination, an example of the operation of the AP 100 and the STA 200 regarding notification of the allowable transmission power value may be similar to the example of operation (example of transmission sequence) shown in FIG. 18.

In FIG. 18, AP1 and AP2 each transmit a beacon signal. At this time, STA1 and STA2 acquire (or generate) measurement information based on the beacon signals of AP1 and AP2. For example, STA1 generates measurement information (e.g., RSSI) regarding received signal power using the beacon signal from AP2. Similarly, for example, STA2 generates measurement information regarding 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 AP2's beacon signal, 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 AP1's beacon signal.

In Figure 18, AP1 sends a Measurement report poll signal to STA1, and AP2 sends a Measurement report poll signal to STA2. When STA1 receives a Measurement report poll signal from AP1, it includes the RSSI generated using the beacon signal from AP2 in the Measurement report and sends it to AP1. Also, when STA2 receives a Measurement report poll signal from AP2, it includes the RSSI generated using the beacon signal from AP1 in the Measurement report and sends it to AP2. Figure 19 shows an example of a Measurement report sent by STA200 (e.g., STA1, STA2). The Measurement report shown in FIG. 19 includes, for example, the transmit power value of the Measurement report by STA 200 ("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) and the RSSI generated using the beacon signal of the corresponding OBSS AP ("RSSI" subfield). In addition, each piece of OBSS information may include beacon signal transmit power information of the corresponding OBSS AP. Each piece of OBSS information may also include path loss information between the corresponding OBSS AP and the STA.

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

For example, AP1 may determine its transmission power value (e.g., 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 (e.g., a Measurement report) and the transmit power value of the Measurement report included in the Measurement report (e.g., 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, IN _STA1,max indicates the maximum interference and noise power received by STA1 from AP2 (e.g., the RSSI of the beacon signal of AP2 notified by STA1 via a Measurement report), SINR _required indicates the SINR required for STA1 to receive a specified MCS, and Pathloss _AP1,STA1 indicates the pathloss value between AP1 and STA1.
TxPower _AP1 = IN _STA1,max + SINR _required + Pathloss _AP1,STA1 (1)

Alternatively, AP1 may receive link margin information from STA1 and determine the transmit power for 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 may determine the transmit power (TxPower _AP1 ) for cooperative communication as a value obtained by adjusting the transmit power of the signal transmitted to STA1 based on the link margin information. The link margin information is a 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)

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

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, 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)

ARIL _STA1 may be derived according to, for example, equation (4).
ARIL _STA1 = TxPower _AP1 - Pathloss _AP1,STA1 - SINR _required (4)

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

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 AP2's transmission power (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 AP100 (including, for example, 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).

AP1 sends a Multi-AP Trigger signal to other APs, which includes AP1's transmission power information (e.g., the Sharing AP Tx power value) and the allowable transmission power information for each other AP (e.g., the Acceptable Tx power value).

In FIG. 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. Also, 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 held in a buffer and the notified relative allowable transmission power value.

Instead of 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. The transmission parameters may include, for example, 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 for beacon signals with different transmission parameters. If the beacon signal of AP2 includes a transmission parameter identifier, AP2 retains information regarding the set of transmission parameter identifiers and transmission power values of the most recently transmitted beacon signal. AP1 transmits to AP2 a Multi-AP Trigger signal including 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 cooperative transmission based on the transmission power value of a beacon signal that matches the transmission parameter identifier included in the Multi-AP Trigger signal.

AP2 may also 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 transmitted power value of the Measurement report included in the Measurement report. AP2 may calculate an expected RSSI at STA2 based on the transmitted power value of AP2 and the path loss value between AP2 and STA2. AP2 may also 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 AP1's beacon signal measured by STA2 (e.g., a received power value at STA2) included in the Measurement report received from STA2 and the transmitted power value of AP1 included in the Multi-AP Trigger signal. AP2 may also 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 STA2's SINR meets a predetermined quality (e.g., an SINR that results in a packet error rate of 10% or less), and may decide not to participate in one-way coordination if STA2's SINR does not meet the predetermined quality.

In Figure 18, after a predetermined time has passed since the Multi-AP Trigger signal was sent and received (for example, after SIFS (Short Inter Frame Space)), AP1 transmits a data signal to STA1 using its transmission power value. If AP2 is participating in one-way coordination, it transmits a data signal to STA2 using its transmission power value. If AP2 is not participating in one-way coordination, it does not transmit a data signal to STA2.

(Variation 1 of another embodiment)
The above-mentioned 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.

For example, when STA1 receives any signal transmitted from AP2, it includes in a Measurement report 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, and sends this to AP1. Figure 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 Figure 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 received signal from the corresponding OBSS AP ("Signal ID" subfield), and the RSSI of the signal received from the corresponding OBSS AP (RSSI subfield).

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

AP1 may derive the 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 the signal identifier included in the Measurement report. Figure 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 Figure 22 includes, in the common information field (Common Info field), the Multi-AP Type subfield, the subtype of the Multi-AP cooperative communication method (Multi-AP subtype), and the transmission power value of the Sharing AP during Multi-AP cooperative communication (Sharing AP Tx power subfield). The Multi-AP Trigger signal includes user information of one or more Shared APs in the user information field (User Info field). The user information for a Shared AP includes the identifier of the corresponding Shared AP (Shared AP ID subfield), the signal identifier of the corresponding Shared AP ("Signal ID" subfield), and the allowable transmit power value of the corresponding Shared AP (Acceptable Tx power subfield).

When AP2 is notified of the relative allowable transmission power value and signal identifier by the Multi-AP Trigger signal received from AP1, it may determine its own transmission power value based on the transmission power value of the signal that matches the signal identifier among the signals held in the buffer and the relative allowable transmission power value.

(Variation 2 of another embodiment)
The above-mentioned 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).

For example, when STA1 receives any signal transmitted from AP2, if the difference (hereinafter 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 send it 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 does not need to send a Measurement report to AP1.

AP1 may derive the 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. 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 there is no update to the allowable transmission power value, AP1 may not need to notify the allowable transmission power value using a Multi-AP Trigger signal.

Figure 23 shows an example of a Multi-Ap Trigger signal that includes an allowable transmission power value and update information for the allowable transmission power value. The Multi-AP Trigger signal shown in Figure 23 includes, in the common information field, the Multi-AP cooperative communication method (Multi-AP Type subfield), the subtype of the Multi-AP cooperative communication method (Multi-AP subtype), and the 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 the user information field (User Info field). The user information of a Shared AP includes the identifier of the corresponding Shared AP (Shared AP ID subfield), the signal identifier of the corresponding Shared AP (Signal ID subfield), update information for the acceptable transmit power value of the corresponding Shared AP ("Update Tx power" subfield), and the acceptable interference power value of the corresponding Shared AP (Acceptable Tx power subfield).

The update information for the allowed transmission power value of the Shared AP (value of the Update Tx power subfield) may be, for example, information indicating whether the allowed transmission power value has changed.

When AP2 is notified by the Multi-AP Trigger signal received from AP1 that the allowable transmission power value is a relative value and that the allowable transmission power value has changed based on the update information, it may determine its transmission power value based on the transmission power value of the most recent signal held in the buffer and the allowable transmission power value in relative value. Also, when AP2 is notified by the Multi-AP Trigger signal received from AP1 that the allowable transmission power value is a relative value and that the allowable transmission power value has not changed based on the update information, it may determine its transmission power value based on the transmission power value of the previous signal held in the buffer.

(Variation 3 of another embodiment)
The above-mentioned allowable transmission power value of the AP 100 may be notified for each frequency resource.

For example, STA1 may generate (or measure) the received power value of the 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.

Figure 24 shows an example of a Measurement report sent by STA1. The Measurement report shown in Figure 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 STA1's Measurement report (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 the identifier of the corresponding OBSS AP (e.g., "AP ID" subfield) and the RSSI (e.g., "RSSI" subfield) for each frequency resource (e.g., RU) of the beacon signal of the corresponding OBSS AP.

AP1 may determine the transmission power value of the Sharing AP (e.g., AP1) for each frequency resource based on the 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 the 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.

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

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) contained in the Multi-AP Trigger signal received from AP1 and the allowable transmission power value for each frequency resource of AP2 (Shared AP).

(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. When there are multiple destination STAs (subordinate STAs) of the Sharing AP, the Sharing AP (e.g., AP1) may include 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 in a Multi-AP Trigger signal 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.

(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.

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

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

Figure 28 shows an example of a Multi-AP Trigger signal transmitted by a Shared AP (AP2). The Multi-AP Trigger signal shown in Figure 28 includes, for example, in the common information field, the Multi-AP cooperative communication method (Multi-AP Type subfield), the 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 (for example, the transmit power derived based on the Multi-AP Trigger signal received from the Sharing AP or Shared AP; AP Tx power subfield). 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 a Shared AP includes the identifier of the corresponding Shared AP (Shared AP ID subfield) and the allowable transmission power value of the corresponding Shared AP (for example, the allowable transmission 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 Figure 27 and the allowable transmission power value included in the user information of AP3 in Figure 28 may be the same value or different values.

An AP (AP3 in Figure 26) that receives a Multi-AP Trigger signal from another Shared AP (AP2 in Figure 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 Figure 28) and the allowable transmission power corresponding to each Shared AP (Acceptable Tx power shown in Figure 28). The Shared AP (AP3) selects the smallest transmission power from the multiple transmission powers derived based on the Multi-AP Trigger signals received from the Sharing AP (AP1) and Shared AP (AP2). As shown in Figure 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 has passed since the response signal was sent and received (e.g., after SIFS), each AP transmits data to its subordinate STAs using the transmission power it has derived.

The Sharing AP may determine the order of the user information of the Shared AP contained in the Multi-AP Trigger signal based on the transmission priority order of the Shared AP. The transmission priority of the Shared AP may be determined by the buffer status notified by the Shared AP, or by the QoS information of the Shared AP.

If the Multi-AP Trigger signal received from another Shared AP does not contain user information addressed to that AP, the Sharing AP and Shared AP do not need to derive the transmission power for Multi-AP coordination.

If the received Multi-AP Trigger signal includes 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 meets the specified quality of the destination STA. For example, if the derived transmit power meets the specified 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 meet the specified 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 may notify "no limit" in the allowable transmit power (Accesptable Tx power subfield) of the other Shared APs. Furthermore, 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 certain AP, it derives the transmission power based on the allowable transmission power indicating a certain value from the certain AP. In other words, when deriving the transmission power, the allowable transmission power indicating a certain value takes priority over the allowable transmission power indicating "no limit."

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

The above describes variations of other embodiments.

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

Also, any combination of variations 1 to 5 may be applied.

The above describes other embodiments.

In the above embodiment, an example of operation has been described in which STA200 generates measurement information upon receiving a transmission signal from AP100, but STA200 may also generate measurement information based on a transmission signal from another STA. STA200 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. In addition, AP100 may receive a transmission signal from STA200 and generate measurement information.

In the above embodiment, an example of operation was described in which the method of determining which STA200's measurement information to include in the Multi-AP request signal and the Multi-AP response signal is determined based on the buffer status, but the parameter used to determine which STA200's measurement information to include is not limited to the buffer status. For example, Quality of Service (QoS) information may 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 of determining which STA200's measurement information to include in the Multi-AP request signal and the Multi-AP response signal, information on the power save state of the STA200 may be used. For example, the AP may determine that the STAs 200 for which measurement information is to be included do not include STAs 200 in a low power state (e.g., doze state, low power listening mode, etc.), but include all or some of the STAs 200 in an active state (e.g., active state). The AP may determine the STAs 200 for which measurement information is to be included based on the priority of data transmission determined using the buffer status, QoS, power saving state, and/or other information of the STAs 200.

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 would be able to conceive of various modifications or alterations within the scope of the claims. Such modifications or alterations are understood to fall within the technical scope of the present disclosure. Furthermore, the components in the embodiments may be combined in any manner as long as they do not deviate from the spirit of the present disclosure.

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

The interface names (frame names), field names, or subfield names described in each of the above embodiments may be other names.

Furthermore, in each of the above-described embodiments, the fields (or subfields) used to notify control information are merely examples, and other fields or subfields may be used. Furthermore, the number of bits used to notify control information in each field or subfield is merely an example, and other numbers of bits may also be used.

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.

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

This 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 realized, in whole or in part, as an LSI, which is an integrated circuit, and each process described in the above embodiments may be controlled, in whole or in part, by a single LSI or a combination of LSIs. An LSI may be composed of individual chips, or may be composed of a single chip that contains some or all of the functional blocks. An LSI may have data input and output. Depending on the level of integration, an LSI may also be called an IC, system LSI, super LSI, or ultra LSI.

The integrated circuit method is not limited to LSI, and may be realized using dedicated circuits, general-purpose processors, or dedicated processors. It is also possible to use FPGAs (Field Programmable Gate Arrays), which can be programmed after LSI manufacturing, or reconfigurable processors, which allow the connections and settings of circuit cells within LSIs to be reconfigured. The present disclosure may be realized as digital processing or analog processing.

Furthermore, if advances in semiconductor technology or other derivative technologies result in the emergence of integrated circuit technology that can replace LSI, it is natural that such technology could be used to integrate functional blocks. The application of biotechnology, for example, is also a possibility.

The present disclosure can be implemented in any type of apparatus, device, or system (collectively referred to as a communications apparatus) with communications capabilities. A communications apparatus may include a radio transceiver and processing/control circuitry. The radio transceiver may include a receiver and a transmitter, or each of these functions. The radio transceiver (transmitter and receiver) may include an RF (Radio Frequency) 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.

Communication devices are not limited to portable or mobile devices, but also include all types of non-portable or fixed equipment, devices, and systems, such as smart home devices (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.

Communications include data communications via cellular systems, wireless LAN systems, communications satellite systems, etc., as well as data communications via combinations of these.

The term "communications apparatus" also includes devices such as controllers and sensors that are connected or coupled to a communications device that performs the communications functions described in this disclosure. For example, it includes controllers and sensors that generate control signals and data signals used by a communications device that performs the communications functions of the communications apparatus.

Furthermore, communication equipment includes infrastructure facilities, such as base stations, access points, and any other equipment, devices, or systems that communicate with or control the various devices listed above, but are not limited to these.

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 are performing cooperative communication based on measurement information from terminals, and a communication circuit that transmits control signals including the parameters to the other access points.

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

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

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.

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.

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

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

In one embodiment of the present disclosure, 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.

In one embodiment of the present disclosure, the control signal includes information regarding whether or not the parameter has been updated.

In one embodiment of the present disclosure, the parameters in the control signal are set for each frequency resource.

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 of the upper limit values corresponding to each of multiple terminals under the access point.

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.

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 control signals from other access points, the control signals including parameters related to transmission power determined based on terminal measurement information, and a control circuit that controls signal transmission based on the parameters.

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.

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 will perform cooperative communication based on measurement information from terminals, and transmits a control signal including the parameters to the other access points.

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 from the terminal, and controls signal transmission based on the parameter.

The entire disclosures of the specification, drawings, and abstract contained in Japanese Patent Application No. 2024-070896, filed April 24, 2024, are incorporated herein by reference.

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

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 transmitting unit 151 BSS measurement information storage unit 152 BSS measurement information storage unit 200 STA
205 Measurement control section 206 Buffer status control section 207 Transmission signal generation section 251 BSS measurement information section 252 BSS measurement information section

Claims (16)

a control circuit that determines parameters related to the transmission power of other access points that perform cooperative communication based on the measurement information of the terminal;
a communication circuit for transmitting a control signal including the parameter to the other access point;
An access point comprising: the control signal includes a transmission power value of the access point and the parameter;
the parameter is an upper limit of the transmission power of the other access point;
The access point of claim 1 . 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.
3. The access point of claim 2. the measurement information includes a received power value of a signal received by the terminal from the other access point;
the control circuit calculates the path loss value based on a transmission power value of the other access point included in the signal received from the other access point and the received power value;
The access point of claim 3 . the measurement information includes a received power value of a signal received by the terminal from the other access point;
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.
3. The access point of claim 2. the control circuit determines a 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.
3. The access point of claim 2. the control circuit calculates the path loss value based on a received power value of the signal received from the terminal and a transmission power value of the measurement information included in the measurement information.
7. The access point of claim 6. 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;
the communication circuit transmits the control signal including the parameter and information identifying the signal.
The access point of claim 1 . The control signal includes information regarding whether or not the parameter is updated.
The access point of claim 1 . In the control signal, the parameter is set for each frequency resource.
The access point of claim 1 . the parameter is an upper limit of the transmission power of the other access point;
the control signal includes a minimum value among the upper limit values corresponding to each of a plurality of terminals under the access point;
The access point of claim 1 . 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.
The access point of claim 1 . An access point that performs cooperative communication,
a communication circuit for receiving a control signal from another access point, the control signal including a parameter related to transmission power determined based on measurement information of the terminal;
a control circuit for controlling transmission of a signal based on the parameter;
An access point comprising: the communication circuit receives the control signals from a plurality of the other access points;
the control circuit selects a minimum value from among the transmission powers determined based on parameters included in the control signals from the plurality of other access points.
14. The access point of claim 13. The access point is
Determine parameters related to the transmission power of other access points that will perform cooperative communication based on the measurement information of the terminal;
transmitting a control signal including the parameter to the other access point;
Communication method. The access points that perform cooperative communication are
receiving a control signal from another access point, the control signal including a parameter related to transmission power determined based on measurement information of the terminal;
controlling the transmission of a signal based on the parameter;
Communication method.