Access point

Abstract

An access point according to an embodiment of the present invention comprises a communication circuit and a processor. The communication circuit is configured to be capable of communicating with a plurality of access points. The processor is configured to determine, on the basis of information regarding each of the plurality of access points, whether each of the access points will use a spatial reuse function, and to apply a spatial reuse function setting based on the determination results to the plurality of assess points.

Description

Access Points

[0001] The embodiments relate to an access point.

[0002] Wireless LANs (local area networks) are known as communication systems that wirelessly connect terminal devices to access points (APs). Terminal devices can access the network via access points within the communication area of ​​a wireless LAN. The Ultra High Reliability - Study Group (UHR-SG), which is studying next-generation wireless LAN systems based on the IEEE 802.11 standard, is studying a multi-AP function that allows multiple access points to operate in coordination.

[0003] In one form of the multi-AP function, multiple second access points connected to a first access point cooperate to perform data communication between the first access point and a terminal device. One example of cooperative operation between multiple second access points is offloading, which distributes traffic between the first access point and a non-AP_MLD (non-access point multi link device) to each second access point. The non-AP_MLD corresponds to a functional block that manages wireless connections, etc., using the multi-AP function in the terminal device.

[0004] In addition, the 802.11 standard is considering a Coordinated Spatial Reuse (Co-SR) function that performs coordinated SR at a second access point to utilize the multi-AP function for spatial reuse (SR). Furthermore, Co-Beamforming and Co-OFDMA (Coordinated Orthogonal Frequency Division Multiple Access) are also being considered as applications of the Co-SR function.

[0005] IEEE 802.11-23 / 0058r0, “Spatial Reuse in Coordinated M-AP for UHR”, January 2023IEEE Std 802.11TM-2020, December 2020

[0006] However, depending on the overlapping degree of OBSS (Overlapping Basic Service Set), the usage scenarios of Co-Beamforming and Co-OFDMA, which are extensions of the Co-SR function, are limited. In other words, the determination of the area where it is better to use the Co-SR function and the area where it is better not to use the Co-SR function depends on the environment. For example, when the overlapping degree of OBSS is large, the effect of power control by using the Co-SR function is reduced, so it is preferable not to use the Co-SR function.

[0007] Therefore, an object of the present invention is to provide an access point that can determine whether or not the access point uses the Co-SR function and can control the on / off of the Co-SR function.

[0008] An access point according to an embodiment includes a communication circuit and a processor. The communication circuit is configured to be able to communicate with a plurality of access points. The processor is configured to determine whether each of the plurality of access points uses a spatial reuse function based on information about each of the plurality of access points, and to apply a setting of the spatial reuse function to the plurality of access points based on a result of the determination.

[0009] According to the present invention, it is possible to provide an access point that can determine whether or not the access point uses the Co-SR function and control the on / off of the Co-SR function.

[0010] FIG. 1 is a block diagram showing an example of the overall configuration of a communication system according to the first embodiment. FIG. 2 is a block diagram showing an example of the hardware configuration of a sharing access point included in the communication system according to the first embodiment. FIG. 3 is a block diagram showing an example of the hardware configuration of a shared access point included in the communication system according to the first embodiment. FIG. 4 is a block diagram showing an example of the hardware configuration of a terminal device included in the communication system according to the first embodiment. FIG. 5 is a block diagram showing an example of the functional configuration of a sharing access point included in the communication system according to the first embodiment. FIG. 6 is a block diagram showing an example of the functional configuration of a shared access point included in the communication system according to the first embodiment. FIG. 7 is a block diagram showing an example of the functional configuration of a terminal device included in the communication system according to the first embodiment. FIG. 8 is a block diagram showing an example of the functional configuration of an affiliated STA included in a terminal device included in the communication system according to the first embodiment. FIG. 9 is a flowchart showing an example of a method for controlling on / off of the Co-SR function by a sharing access point included in the communication system according to the first embodiment. FIG. 10 is a schematic diagram showing an example of a method for acquiring information used to determine on / off of the Co-SR function in the communication system according to the first embodiment. FIG. 11 is a schematic diagram for explaining a first usage condition of the Co-SR function in the communication system according to the first embodiment. FIG. 12 is a schematic diagram illustrating a second use condition of the Co-SR function in the communication system according to the first embodiment. FIG. 13 is a schematic diagram illustrating a third use condition of the Co-SR function in the communication system according to the first embodiment. FIG. 14 is a schematic diagram illustrating a fourth use condition of the Co-SR function in the communication system according to the first embodiment. FIG. 15 is a flowchart showing an example of a method for controlling on / off of the Co-SR function by a shared access point included in the communication system according to the second embodiment. FIG. 16 is a schematic diagram showing an example of a method for acquiring information used to determine on / off of the Co-SR function in the communication system according to the second embodiment. FIG. 17 is a schematic diagram illustrating the use conditions of the Co-SR function in the communication system according to the second embodiment.FIG. 18 is a block diagram illustrating an example of the configuration of a communication system according to a modification of the first embodiment.

[0011] Each embodiment will be described below with reference to the drawings. Each embodiment illustrates an apparatus or method for embodying the technical idea of ​​the invention. The drawings are schematic or conceptual. Components having substantially the same function and configuration are assigned the same reference numerals. The number following a letter constituting a reference numeral is used to distinguish between elements that are referred to by reference numerals containing the same letter and have similar configurations. Similarly, a "hyphen + number" following a number constituting a reference numeral is used to distinguish between elements that are referred to by reference numerals containing the same number and have similar configurations.

[0012] Hereinafter, "access point" will be abbreviated as "AP" where appropriate. In this specification, a wireless LAN access point may be referred to as a "base station." In this specification, a first access point in the multi-AP function is referred to as a "sharing access point," and a second access point in the multi-AP function is referred to as a "shared access point." In this specification, using the Co-SR function corresponds to enabling the Co-SR function (on state). Not using the Co-SR function corresponds to disabling the Co-SR function (off state).

[0013] <1> First Embodiment In a communication system 1 according to a first embodiment, a sharing AP is configured to control the on / off of the Co-SR function based on information from a subordinate shared AP. Details of the communication system 1 according to the first embodiment will be described below.

[0014] <1-1> Configuration First, a description will be given of the configuration of the communication system 1 according to the first embodiment. The following description will be given on the assumption that a multi-AP connection using the multi-AP function has been established in the communication system 1.

[0015] <1-1-1> Overall configuration of communication system 1 Fig. 1 is a block diagram showing an example of the overall configuration of a communication system 1 according to the first embodiment. As shown in Fig. 1, the communication system 1 includes a sharing AP 10, a plurality of shared APs 20, and a terminal device 30.

[0016] The sharing AP 10 is a type of wireless LAN access point. The sharing AP 10 is connected to a network NW. The sharing AP 10 is configured to be able to communicate by wire or wireless with a server (not shown) on the network NW, and to be able to communicate wirelessly with each of the multiple shared APs 20. The sharing AP 10 establishes a multi-AP connection with the non-AP_MLD of the terminal device 30.

[0017] The shared AP 20 is a type of wireless LAN access point. The shared AP 20 is configured to be able to wirelessly communicate with both the sharing AP 10 and the terminal device 30. Multiple shared APs 20 are installed at locations distant from each other and have different communication areas. The communication area of ​​each shared AP 20 may overlap with the communication area of ​​another shared AP 20. Figure 1 shows two shared APs 20-1 and 20-2 connected to the sharing AP 10.

[0018] The terminal device 30 is a wireless terminal such as a smartphone or a PC (Personal Computer). The terminal device 30 has multiple affiliated stations (STAs) (hereinafter also referred to as "A-STAs") and a non-AP_MLD. The multiple affiliated STAs include A-STA1 wirelessly connected to a shared AP 20-1 and A-STA2 wirelessly connected to a shared AP 20-2. The wireless connection between the shared AP 20 and the affiliated STAs corresponds to a conventional connection between a pair of access points and an STA. Each A-STA can switch its connection destination to another shared AP 20 as the terminal device 30 moves. The non-AP_MLD is a multi-link device (MLD) that manages the link status and wireless communication of each of the multiple A-STAs. The non-AP_MLD can establish a multi-AP connection with the sharing AP 10 via a plurality of affiliated STAs and a plurality of shared APs 20, and exchange data and the like.

[0019] When a multi-AP connection is established in the communication system 1, information on the multiple shared APs 20 under the sharing AP 10 and information on the multiple affiliated STAs under the non-AP_MLD are mutually exchanged between the sharing AP 10 and the non-AP_MLD. This allows the communication system 1 to collectively establish a comprehensive connection between the sharing AP 10 and the non-AP_MLD for the multiple shared APs 20 and the multiple affiliated STAs.

[0020] The wireless communication used in the communication system 1 complies with, for example, the IEEE 802.11 standard. The IEEE 802.11 standard has wireless communication functions based on the OSI (Open Systems Interconnection) reference model. In the OSI reference model, wireless communication functions are divided into seven layers (Layer 1: Physical Layer, Layer 2: Data Link Layer, Layer 3: Network Layer, Layer 4: Transport Layer, Layer 5: Session Layer, Layer 6: Presentation Layer, and Layer 7: Application Layer). The data link layer includes an LLC (Logical Link Control) sublayer and a MAC (Media Access Control) sublayer. Frequency bands used in the wireless communication of the communication system 1 may include, for example, the 2.4 GHz band, the 5 GHz band, the 6 GHz band, the 45 GHz band, and the 60 GHz band. Multiple channels may be assigned to each frequency band. Different channels or the same channel may be assigned to A-STA1 and A-STA2. Furthermore, A-STA1 and A-STA2 may use the same frequency band, or different frequency bands.

[0021] <1-1-2> Hardware Configuration of Communication System 1 The hardware configuration of the communication system 1 according to the first embodiment will be described below.

[0022] 2 is a block diagram showing an example of the hardware configuration of the sharing AP 10 included in the communication system 1 according to the first embodiment. As shown in FIG. 2, the sharing AP 10 includes, for example, a central processing unit (CPU) 11, a read-only memory (ROM) 12, a random access memory (RAM) 13, a wireless communication module 14, and a wired communication module 15.

[0023] The CPU 11 is an integrated circuit capable of executing various programs and controls the overall operation of the sharing AP 10. The ROM 12 is, for example, a non-volatile semiconductor memory that stores programs and control data for controlling the sharing AP 10. The RAM 13 is, for example, a volatile semiconductor memory that is used as a work area for the CPU 11. The wireless communication module 14 is configured to be able to send and receive wireless signals via an antenna. The wireless communication module 14 is used to send and receive data, etc., to and from each shared AP 20. The wired communication module 15 is a circuit used to send and receive data, etc., via wired signals. The wired communication module 15 is configured to be connectable to a network NW.

[0024] The sharing AP 10 may have other hardware configurations. For example, when the sharing AP 10 is wirelessly connected to the network NW, the wired communication module 15 may be omitted from the sharing AP 10. When the sharing AP 10 is wiredly connected to the network NW, the wireless communication module 14 may be omitted from the sharing AP 10. The antenna may be built into the sharing AP 10 or may be externally connected.

[0025] (2: Hardware Configuration of Shared AP 20) Fig. 3 is a block diagram showing an example of the hardware configuration of the shared AP 20 included in the communication system 1 according to the first embodiment. As shown in Fig. 3, the shared AP 20 includes, for example, a CPU 21, a ROM 22, a RAM 23, and a wireless communication module 24, as shown in Fig. 2.

[0026] The CPU 21 is an integrated circuit capable of executing various programs and controls the overall operation of the shared AP 20. The ROM 22 is, for example, a non-volatile semiconductor memory and stores programs and control data for controlling the shared AP 20. The RAM 23 is, for example, a volatile semiconductor memory and is used as a work area for the CPU 21. The wireless communication module 24 is configured to be able to send and receive wireless signals via an antenna. The wireless communication module 24 is used to send and receive data, etc., to and from the sharing AP 10 and to and from the terminal device 30.

[0027] The shared AP 20 may have other hardware configurations. For example, the antenna may be built into the shared AP 20 or may be externally connected. The shared AP 20 may be connected to the sharing AP 10 via a wire. In this case, the shared AP 20 further includes a wired communication module configured to be able to communicate with the sharing AP 10. The communication system 1 may include both a shared AP 20 connected to the sharing AP 10 via a wire and a shared AP 20 connected to the sharing AP 10 wirelessly.

[0028] 4 is a block diagram showing an example of the hardware configuration of the terminal device 30 included in the communication system 1 according to the first embodiment. As shown in FIG. 4, the terminal device 30 includes, for example, a CPU 31, a ROM 32, a RAM 33, a wireless communication module 34, a display 35, and a storage 36.

[0029] The CPU 31 is an integrated circuit capable of executing various programs and controls the overall operation of the terminal device 30. The ROM 32 is, for example, a non-volatile semiconductor memory and stores programs and control data for controlling the terminal device 30. The RAM 33 is, for example, a volatile semiconductor memory and is used as a work area for the CPU 31. The wireless communication module 34 is configured to be able to send and receive wireless signals via an antenna. The wireless communication module 34 is used to send and receive data to and from the shared AP 20. The display 35 is, for example, a liquid crystal display (LCD) or an electro-luminescence (EL) display. The display 35 displays, for example, a graphical user interface (GUI) corresponding to application software. The storage 36 is a non-volatile storage device and stores, for example, system software for the terminal device 30.

[0030] The terminal device 30 may have other hardware configurations. For example, if the terminal device 30 is an IoT (Internet of Things) terminal or the like, the display 35 may be omitted from the terminal device 30. The display 35 may function as an input interface for the terminal device 30. The antenna may be built into the terminal device 30 or may be externally connected.

[0031] <1-1-3> Functional Configuration of Communication System 1 The functional configuration of the communication system 1 according to the first embodiment will be described below.

[0032] (1: Functional Configuration of Sharing AP 10) FIG. 5 is a block diagram showing an example of the functional configuration of the sharing AP 10 included in the communication system 1 according to the first embodiment. As shown in FIG. 5, the sharing AP 10 functions as a computer including, for example, an LLC processing unit 110, a data processing unit 120, a management unit 130, a frame processing unit 140, and a transmission / reception unit 150. The LLC processing unit 110 is a functional block that executes processing corresponding to the LLC sublayer of layer 2 and layers 3 to 7. The data processing unit 120, the management unit 130, and the frame processing unit 140 are functional blocks that execute processing corresponding to the MAC sublayer of layer 2. The transmission / reception unit 150 is a functional block that executes processing corresponding to layer 1.

[0033] The LLC processing unit 110 generates LLC packets by, for example, adding a DSAP (Destination Service Access Point) header or an SSAP (Destination Service Access Point) header to data received from the network NW. The LLC processing unit 110 then inputs the generated LLC packets to the data processing unit 120. The LLC processing unit 110 also extracts data from the LLC packets input from the data processing unit 120. The LLC processing unit 110 then transmits the extracted data to the network NW.

[0034] Data processing unit 120 generates a MAC frame by adding a MAC header to the LLC packet input from LLC processing unit 110. Data processing unit 120 then inputs the generated MAC frame to frame processing unit 140. Data processing unit 120 also extracts LLC packets from the MAC frame input from frame processing unit 140. Data processing unit 120 then inputs the extracted LLC packets to LLC processing unit 110. A MAC frame containing data is also called a "data frame."

[0035] The management unit 130 performs tasks such as establishing a wireless connection (wireless link) with the non-AP_MLD of the terminal device 30, mapping data types to links, setting up BlockAck, and controlling the Co-SR (Coordinated-Spatial Reuse) function. For example, the management unit 130 executes multi-AP association processing in response to a multi-AP association request from the terminal device 30. For example, when the terminal device 30 uses two APs, A-STA1 and A-STA2, the multi-AP association processing causes A-STA1 to establish a wireless link with the shared AP 20-1, and A-STA2 to establish a wireless link with the shared AP 20-2.

[0036] The management unit 130 also includes multi-AP management information 131, link management information 132, and a determination unit 133. The multi-AP management information 131 includes information regarding the access points used in the multi-AP connection (i.e., the sharing AP 10 and the shared APs 20-1 and 20-2) and the terminal device 30. For example, the multi-AP management information 131 is provided for each terminal device 30 that establishes a multi-AP connection. The link management information 132 includes information regarding the status of the links established in the multi-AP connection. The determination unit 133 determines whether to set the Co-SR function of the subordinate shared AP 20 to an on state (enabled) or an off state (disabled) based on information from the subordinate shared AP 20. The sharing AP 10 then notifies each shared AP 20 of the determination result. The information regarding the subordinate shared AP 20 may be stored in the management unit 130 or may be acquired from the subordinate shared AP 20. The determination unit 133 also detects a notification transmitted from the subordinate shared AP 20 as to whether or not to use the Co-SR function.

[0037] When a MAC frame is input from the data processing unit 120 or the management unit 130, the frame processing unit 140 outputs the input MAC frame to the transceiver unit 150. Furthermore, when a MAC frame is input from the transceiver unit 150, the frame processing unit 140 outputs the input frame to the data processing unit 120 or the management unit 130 depending on the frame type. For example, when a data frame is input from the transceiver unit 150, the frame processing unit 140 outputs the input frame to the data processing unit 120. When a management frame or a control frame is input from the transceiver unit 150, the frame processing unit 140 outputs the input frame to the management unit 130. The management frame or the control frame includes, for example, management information. The management information may include notification information for either the shared AP 20 or the terminal device 30, control information related to control of the operation of either the shared AP 20 or the terminal device 30, and the like.

[0038] The transceiver 150 transmits and receives data, management information, and the like to and from each of the multiple shared APs 20 belonging to the sharing AP 10. The transceiver 150 is provided with, for example, one wireless signal processing unit for each of the multiple shared APs 20 belonging to the sharing AP 10. Each wireless signal processing unit of the transceiver 150 is configured to transmit and receive wireless signals using a different frequency band or channel.

[0039] Each wireless signal processing unit of the transceiver 150 generates a wireless frame by adding a preamble or the like to the MAC frame input from the frame processing unit 140, and converts the generated wireless frame into a wireless signal. Each wireless signal processing unit then transmits (radiates) the converted wireless signal via an antenna to the wirelessly connected shared AP 20. Each wireless signal processing unit of the transceiver 150 also converts a wireless signal received from one of the shared APs 20 via the antenna into a wireless frame. Each wireless signal processing unit then extracts a MAC frame from the converted wireless frame and outputs the extracted MAC frame to the frame processing unit 140. The transceiver 150 may use multicast or broadcast when simultaneously notifying multiple shared APs 20. Multicast and broadcast are used, for example, to transmit beacons and the like.

[0040] The multi-AP management information 131 may include information related to frequency bands, channels, operational parameters, access categories, etc. The frequency band information indicates, for example, the frequency band used by the A-STA for the wireless link. The channel information indicates, for example, the channel used by the A-STA for the wireless link. The operational parameter information includes, for example, CWmin, CWmax, AIFS (arbitration interframe space), and TXOP (transmission opportunity) Limit. CWmin and CWmax indicate the minimum and maximum values ​​of the contention window, respectively. The contention window is a parameter used to calculate backoff, which is a transmission waiting time for collision avoidance. AIFS is a fixed transmission waiting time set for each access category of traffic. TXOPLimit indicates the upper limit of the channel occupation period TXOP. The access category information is indicated by, for example, "VO (Voice)," "VI (Video)," "BE (Best Effort)," "BK (Background)," and "LL (Low Latency)." The multi-AP management information 131 may also store whether the Co-SR function of the subordinate shared AP 20 is enabled or disabled.

[0041] The link management information 132 may include information indicating whether a wireless link is enabled or disabled. The multi-AP management information 131 and the link management information 132 may be integrated. Based on the multi-AP management information 131, the frame processing unit 140 may output data to be transmitted to the shared AP 20-1 to a wireless signal processing unit associated with the shared AP 20-1, and output data to be transmitted to the shared AP 20-2 to a wireless signal processing unit associated with the shared AP 20-2. The frame processing unit 140 may determine the destination of the MAC frame input from the data processing unit 120 based on a traffic identifier (TID) associated with an access category. This process of associating a TID with a link is also referred to as "TID-link mapping." The transceiver unit 150 may be provided with a wireless signal processing unit assigned to transmitting and receiving data, etc., as well as a wireless signal processing unit assigned to transmitting management information.

[0042] (2: Functional Configuration of Shared AP 20) Fig. 6 is a block diagram showing an example of the functional configuration of the shared AP 20 included in the communication system 1 according to the first embodiment. As shown in Fig. 6, the shared AP 20 functions as a computer including, for example, transmission / reception units 210-1 and 210-2, a management unit 220, frame processing units 230-1 and 230-2, and a data processing unit 240. The transmission / reception units 210-1 and 210-2 are functional blocks that execute processing corresponding to the first layer. The management unit 220 and frame processing units 230-1 and 230-2 are functional blocks that execute processing corresponding to the MAC sublayer of the second layer.

[0043] The transceiver 210-1 transmits and receives data, management information, and the like to and from the sharing AP 10 via wireless communication. The transceiver 210-2 transmits and receives data, management information, and the like to and from the terminal device 30 via wireless communication. The transceivers 210-1 and 210-2 are associated with the frame processors 230-1 and 230-2, respectively. The transceiver 210-2 may use multicast or broadcast when notifying the terminal device 30. Multicast or broadcast is used, for example, to transmit beacons or the like that include information about multi-AP connections. Each of the transceivers 210-1 and 210-2 includes a wireless signal processor. Note that in the shared AP 20, the wireless signal processor of the transceiver 210-1 and the wireless signal processor of the transceiver 210-2 are preferably configured to use different frequency bands or channels.

[0044] The radio signal processing unit of the transceiver unit 210-1 generates a radio frame by adding a preamble or the like to the MAC frame (data frame, management frame, etc.) input from the frame processing unit 230-1. Then, the radio signal processing unit of the transceiver unit 210-1 converts the generated radio frame into a radio signal and transmits (radiates) the converted radio signal to the sharing AP 10 via the antenna. Furthermore, the radio signal processing unit of the transceiver unit 210-1 converts the radio signal received from the sharing AP 10 via the antenna into a radio frame. Then, the radio signal processing unit of the transceiver unit 210-1 extracts the MAC frame from the converted radio frame and outputs the extracted MAC frame to the frame processing unit 230-1.

[0045] The radio signal processing unit of the transceiver unit 210-2 generates a radio frame by adding a preamble or the like to the MAC frame (data frame, management frame, etc.) input from the frame processing unit 230-2. The radio signal processing unit of the transceiver unit 210-2 then converts the generated radio frame into a radio signal and transmits (radiates) the converted radio signal to the terminal device 30 via the antenna. The radio signal processing unit of the transceiver unit 210-2 also converts a radio signal received from the terminal device 30 via the antenna into a radio frame. The radio signal processing unit of the transceiver unit 210-2 extracts a MAC frame from the converted radio frame and outputs the extracted MAC frame to the frame processing unit 230-2.

[0046] The management unit 220 controls the establishment of a wireless connection (wireless link) between the sharing AP 10 in the multi-AP connection and the non-AP MLD of the terminal device 30. Furthermore, based on a notification from the sharing AP 10, the management unit 220 generates and distributes beacons necessary for the multi-AP connection, manages the status of the wireless link between the A-AP of the shared AP 20 in the multi-AP connection and the A-STA of the terminal device 30, and controls the Co-SR (Coordinated-Spatial Reuse) function. Furthermore, the management unit 220 includes link management information 221 and a determination unit 222.

[0047] The link management information 221 stores management information regarding the status of wireless links used in a multi-AP connection. The link management information 221 also includes, for example, the identifier of the sharing AP 10 to which the local station belongs and the identifier of the A-STA of the terminal device 30 that has established a wireless link with the local station. The link management information 221 may store information included in the multi-AP management information 131 and the link management information 132. The management unit 220 manages the validity and invalidity of wireless links using the link management information 221. The determination unit 222 detects signals from subordinate terminal devices 30 and performs a determination process, which will be described later. In the determination process, the determination unit 222 determines whether to set the Co-SR function to an on state (enabled) or an off state (disabled) based on information from the subordinate terminal devices 30. Information about the subordinate terminal devices 30 is acquired from the subordinate terminal devices 30. The determination unit 222 may notify the sharing AP 10 of the determination result. A specific method for using the determination unit 222 will be described in the second embodiment.

[0048] When a MAC frame is input from the data processing unit 240, the frame processing unit 230-1 outputs the input frame to the transceiver unit 210-1. When a MAC frame is input from the transceiver unit 210-1, the frame processing unit 230-1 outputs the input MAC frame to the management unit 220 or the data processing unit 240, depending on the frame type. For example, when a data frame is input from the transceiver unit 210-1, the frame processing unit 230-1 outputs the input frame to the data processing unit 240. When a management frame or control frame intended for the frame processing unit 230-1 is input from the transceiver unit 210-1, the frame processing unit 230-1 outputs the input frame to the management unit 220.

[0049] When a MAC frame is input from the data processing unit 240, the frame processing unit 230-2 outputs the input frame to the transceiver unit 210-2. When a MAC frame is input from the transceiver unit 210-2, the frame processing unit 230-2 outputs the input MAC frame to the management unit 220 or the data processing unit 240, depending on the frame type. For example, when a data frame is input from the transceiver unit 210-2, the frame processing unit 230-2 outputs the input frame to the data processing unit 240. When a management frame or control frame intended for the frame processing unit 230-2 is input from the transceiver unit 210-2, the frame processing unit 230-2 outputs the input frame to the management unit 220.

[0050] Data processing unit 240 outputs the MAC frame input from frame processing unit 230-1 to frame processing unit 230-2, and also outputs the MAC frame input from frame processing unit 230-2 to frame processing unit 230-1.

[0051] (3: Functional Configuration of Terminal Device 30) FIG. 7 is a block diagram showing an example of the functional configuration of the terminal device 30 included in the communication system 1 according to the first embodiment. As shown in FIG. 7, the terminal device 30 functions as a computer including, for example, an application execution unit 300, an LLC processing unit 310, a data processing unit 320, a management unit 330, a frame processing unit 340, and A-STA1 and A-STA2. The application execution unit 300 is a functional block that executes processing corresponding to layer 7. The LLC processing unit 310 is a functional block that executes processing corresponding to the LLC sublayer of layer 2 and layers 3 to 6. The data processing unit 320, the management unit 330, and the frame processing unit 340 are functional blocks that execute processing corresponding to the MAC sublayer of layer 2. A-STA1 and A-STA2 are functional blocks that execute processing corresponding to the MAC sublayer of layer 2 and layer 1. For example, a set of LLC processing unit 310, data processing unit 320, management unit 330, and frame processing unit 340 corresponds to non-AP_MLD.

[0052] The application execution unit 300 executes an application based on data input from the LLC processing unit 310. The application execution unit 300 also outputs data to the LLC processing unit 310. For example, the application execution unit 300 can display application information on the display 35. The application execution unit 300 can also operate based on operations on an input interface.

[0053] The LLC processing unit 310 generates LLC packets by adding DSAP headers, SSAP headers, etc. to data input from the application execution unit 300 (upper layer). The LLC processing unit 310 then outputs the generated LLC packets to the data processing unit 320. The LLC processing unit 310 also extracts data from the LLC packets input from the data processing unit 320. The LLC processing unit 310 then outputs the extracted data to the application execution unit 300 (upper layer).

[0054] The data processing unit 320 generates a MAC frame by adding a MAC header to the LLC packet input from the LLC processing unit 310. The data processing unit 320 then outputs the generated MAC frame to the frame processing unit 340. The data processing unit 320 also extracts an LLC packet from the MAC frame input from the frame processing unit 340. The data processing unit 320 then outputs the extracted LLC packet to the LLC processing unit 310.

[0055] The management unit 330 establishes a wireless connection (wireless link) with the sharing AP 10, maps data types to links, sets up BlockAck, and so on. The management unit 330 can acquire management information from, for example, a beacon received from the shared AP 20. The management unit 330 also manages the status of the wireless link between the A-AP of the shared AP 20 and the A-STA of the terminal device 30 in a multi-AP connection. The management unit 330 also includes link management information 331.

[0056] The link management information 331 stores management information related to the status of wireless links used in a multi-AP connection. The link management information 331 also includes, for example, information related to the identifier of the sharing AP 10 to which the local station belongs and the identifier of the shared AP 20 that has established a wireless link with the local station. The link management information 331 may store information included in the multi-AP management information 131 and the link management information 132. The management unit 330 uses the link management information 331 to manage whether wireless links are enabled or disabled.

[0057] When a MAC frame is input from the data processing unit 320, the frame processing unit 340 outputs the input frame to at least one of A-STA1 and A-STA2 in accordance with traffic allocation. Furthermore, when a MAC frame is input from either A-STA1 or A-STA2, the frame processing unit 340 outputs the input frame to the management unit 330 or the data processing unit 320 in accordance with the frame type. For example, when a data frame is input from either A-STA1 or A-STA2, the frame processing unit 340 outputs the input frame to the data processing unit 320. When a data frame is input from the data processing unit 320, the frame processing unit 340 outputs the input frame to either A-STA1 or A-STA2. When a management frame or control frame intended for the own station is input from either A-STA1 or A-STA2, the frame processing unit 340 outputs the input frame to the management unit 330.

[0058] Each of A-STA1 and A-STA2 functions as a wireless signal processing unit configured to be able to transmit and receive data, management information, and the like to and from the shared AP 20 via wireless communication. The A-STA generates a wireless frame by adding a preamble, etc., to the MAC frame input from the frame processing unit 340. The A-STA then converts the generated wireless frame into a wireless signal. The A-STA then transmits (radiates) the converted wireless signal via an antenna to the wirelessly connected shared AP 20. The A-STA also converts a wireless signal received from the wirelessly connected shared AP 20 via an antenna into a wireless frame. The A-STA extracts a MAC frame from the converted wireless frame and outputs the extracted MAC frame to the frame processing unit 340.

[0059] 8 is a block diagram showing an example of the functional configuration of an affiliated STA (A-STA) included in the terminal device 30 of the communication system 1 according to the first embodiment. As shown in FIG. 8, the A-STA includes a MAC frame generation unit 351, a transmission / reception unit 352, and a MAC frame processing unit 353.

[0060] The MAC frame generation unit 351 generates a MAC frame by adding a MAC header and the like to the data and the like input from the frame processing unit 340, and outputs the MAC frame to the transmission / reception unit 352. The MAC header includes a sequence number SN assigned to identify the data. In other words, the sequence number SN is output from the transmission buffer of the non-AP_MLD together with the data.

[0061] The transmitting / receiving unit 352 performs wireless processing and transmits the MAC frame input from the MAC frame generating unit 351. On the other hand, the transmitting / receiving unit 352 extracts a MAC frame from a wireless signal received via an antenna and outputs the MAC frame to the MAC frame processing unit 353.

[0062] The MAC frame processing unit 353 determines whether the MAC frame input from the transmitting / receiving unit 352 has been correctly received based on the frame check sequence. Then, the MAC frame processing unit 353 outputs the correctly received data to the non-AP_MLD frame processing unit 340.

[0063] <1-2> Operation Next, the operation of the communication system 1 according to the first embodiment will be described.

[0064] <1-2-1> Method for Controlling On / Off of Co-SR Function FIG. 9 is a flowchart showing an example of a method for controlling on / off of the Co-SR function by the sharing AP 10 included in the communication system 1 according to the first embodiment.

[0065] The sharing AP 10 periodically executes (starts) the series of processes shown in Fig. 9 based on a predetermined schedule, for example. The series of processes shown in Fig. 9 may be started based on a user operation or a predetermined trigger.

[0066] First, the sharing AP 10 acquires information about the subordinate shared APs 20 (step S10). The details of this information about the subordinate shared APs 20 will be described later.

[0067] Next, the sharing AP 10 determines whether to use the Co-SR function (step S11). Specifically, the determination unit 133 of the sharing AP 10 executes a determination process. In the determination process, the determination unit 133 determines whether to set the Co-SR function to ON or OFF, using the information about the subordinate shared AP 20 acquired in the process of step S10 and the preset conditions for using the Co-SR function.

[0068] Next, the sharing AP 10 checks whether the determination result is different from the current usage status of the Co-SR function (step S12). At this time, the determination unit 133 acquires the current usage status of the Co-SR function from, for example, the link management information 132.

[0069] In the process of step S12, if it is confirmed that the determination result is the same as the current usage status of the Co-SR function (step S12: NO), the sharing AP 10 ends the series of processes in Fig. 9 (END). For example, if the Co-SR function is enabled in the subordinate shared AP 20 and the determination result in step S11 indicates that the Co-SR function should be enabled, the sharing AP 10 maintains the current setting of the Co-SR function of the subordinate shared AP 20.

[0070] In the processing of step S12, if it is confirmed that the judgment result is different from the current usage status of the Co-SR function (step S12: YES), the sharing AP 10 notifies the shared AP 20 of the judgment result (step S13).

[0071] After the process of step S13, the sharing AP 10 sets the Co-SR function based on the determination result (step S14). Then, the sharing AP 10 ends the series of processes shown in Fig. 9 (end). For example, if the Co-SR function is off in the subordinate shared AP 20 and the determination result of step S11 indicates that the Co-SR function should be turned on, the sharing AP 10 turns on the Co-SR function of the subordinate shared AP 20 by the process of step S14.

[0072] <1-2-2> Method for collecting information used to determine whether the Co-SR function is on or off Figure 10 is a schematic diagram showing an example of a method for acquiring information used to determine whether the Co-SR function is on or off in the communication system 1 according to the first embodiment. The following describes an example in which terminal devices 30-1, 30-2, and 30-3 are connected to the shared AP 20-1, and terminal devices 30-4, 30-5, and 30-6 are connected to the shared AP 20-2, as shown in Figure 10. Note that the connection between the shared AP 20 and the terminal devices 30 may be a multi-link or a single-link.

[0073] 10 , the sharing AP 10 transmits a wireless frame including a request to a subordinate shared AP 20 in order to collect information used to configure the Co-SR function. Based on the received request, the subordinate shared AP 20 then notifies the sharing AP 10 of information used to determine whether to enable or disable the Co-SR function. The sharing AP 10 may store the request in a beacon signal transmitted by multicast or broadcast, or may transmit the request to each shared AP 20.

[0074] The shared AP 20 may store information used to determine whether the Co-SR function is on or off in an element added to, for example, an action frame or a beacon frame format. By notifying the information via such a wireless frame, the shared AP 20 can indicate to the sharing AP 10 its intention to use the Co-SR function.

[0075] The shared AP 20 may add a block or element for notifying information to the trigger frame or BlockAck and transmit the added block or element. The shared AP 20 may also be configured to voluntarily notify the sharing AP 10 of information. In this case, the sharing AP 10 may omit sending a request to the shared AP 20 regarding the notification of the information.

[0076] <1-2-3> Conditions for Using the Co-SR Function An example of the conditions for using the Co-SR function that are referenced in the determination operation is described below. Note that the communication system 1 shown in the drawing for explaining the conditions for using the Co-SR function has the same configuration as that shown in FIG. 10.

[0077] (1: First Use Condition) Fig. 11 is a schematic diagram for explaining a first use condition of the Co-SR function in the communication system 1 according to the first embodiment. The first use condition of the Co-SR function in the first embodiment is that the number of shared APs 20 that want to use the Co-SR function is equal to or greater than a predetermined number. In the example shown in Fig. 11, the first use condition of the Co-SR function is set to be that the number of shared APs 20 that want to use the Co-SR function is equal to or greater than two.

[0078] In this example, each of the shared APs 20-1 and 20-2 indicates its intention to use the Co-SR function ("O" in FIG. 11). Therefore, the sharing AP 10 instructs each of the shared APs 20-1 and 20-2 to enable the Co-SR function. Then, each of the shared APs 20-1 and 20-2 starts using the Co-SR function. In this way, the sharing AP 10 can determine whether to use the Co-SR function based on the number of shared APs 20 that want to use the Co-SR function.

[0079] In the first usage condition for the Co-SR function, each shared AP 20 may notify the sharing AP 10 of binary information indicating whether or not it wants to use the Co-SR function. Alternatively, each shared AP 20 may notify the sharing AP 10 of its intention to use the Co-SR function using a value greater than two. For example, the degree of request for the Co-SR function is indicated on a four-level scale from 0 to 3. In this case, the sharing AP 10 determines whether to use the Co-SR function based on, for example, the total degree of request for the Co-SR function of the shared APs 20 under its control and a predetermined threshold value.

[0080] (2: Second Use Condition) FIG. 12 is a schematic diagram illustrating a second use condition for the Co-SR function in the communication system 1 according to the first embodiment. The second use condition for the Co-SR function in the first embodiment is that the distance between two shared APs 20 (inter-shared AP distance) is greater than a predetermined distance. In the example shown in FIG. 12, the second use condition for the Co-SR function is set to be that the inter-shared AP distance exceeds Dth. Dth is set to a value that provides a favorable effect of power control when the two shared APs 20 use the Co-SR function, for example.

[0081] In this example, the inter-shared AP distance between the shared APs 20-1 and 20-2 is greater than Dth. Therefore, the sharing AP 10 instructs each of the shared APs 20-1 and 20-2 to enable the Co-SR function. Then, each of the shared APs 20-1 and 20-2 starts using the Co-SR function. In this way, the sharing AP 10 can determine whether to use the Co-SR function based on the inter-shared AP distance. In other words, the sharing AP 10 can determine whether to use the Co-SR function based on the location of the shared AP 20.

[0082] The sharing AP 10 may estimate the location of the shared AP 20 based on the power level of a signal received from the shared AP 20. The sharing AP 10 may also store information on the location coordinates of each shared AP 20 in advance. In this case, the sharing AP 10 may calculate the distance between the shared APs based on the information on the location coordinates of each shared AP 20. Each shared AP 20 may be equipped with a global positioning system (GPS) and may be configured to notify the sharing AP 10 of location information acquired by the GPS. In this case, the sharing AP 10 may calculate the distance between the shared APs based on the location information received from each shared AP 20.

[0083] The second usage condition for the Co-SR function can also be used when there are three or more shared APs 20. The process of determining whether to enable or disable the Co-SR function is performed for each shared AP 20, for example, using the inter-AP distance between the shared AP 20 and the closest shared AP 20. The second usage condition for the Co-SR function may be combined with the first usage condition for the Co-SR function. In this case, the sharing AP 10 determines whether to use the Co-SR function of each shared AP 20 based on the number of shared APs 20 that want to use the Co-SR function and the inter-AP distance between the shared APs 20.

[0084] (3: Third Use Condition) FIG. 13 is a schematic diagram for explaining a third use condition of the Co-SR function in the communication system 1 according to the first embodiment. The third use condition of the Co-SR function in the first embodiment is that the subordinate shared AP 20 uses beamforming. In the example shown in FIG. 13, each of the shared APs 20-1 and 20-2 uses beamforming. Therefore, the sharing AP 10 instructs each of the shared APs 20-1 and 20-2 to enable the Co-SR function. Then, each of the shared APs 20-1 and 20-2 starts using the Co-SR function. In this way, the sharing AP 10 can determine whether to use the Co-SR function according to the beamforming setting of the shared AP.

[0085] The sharing AP 10 may refer to detailed beamforming settings in the third usage condition for the Co-SR function. For example, the sharing AP 10 may determine whether to enable the Co-SR function based on signal directivity information based on the beamforming settings. Furthermore, the third usage condition for the Co-SR function may determine whether to enable the Co-SR function depending on the number of shared APs 20 using beamforming. For example, the sharing AP 10 enables the Co-SR function when the number of shared APs 20 using beamforming exceeds a predetermined threshold.

[0086] (4: Fourth Use Condition) FIG. 14 is a schematic diagram illustrating a fourth use condition of the Co-SR function in the communication system 1 according to the first embodiment. The fourth use condition of the Co-SR function in the first embodiment is whether or not the number of terminal devices 30 that are detected by the shared AP 20 but are not detected by other shared APs 20 is equal to or greater than a predetermined number. In the example shown in FIG. 14, the fourth use condition of the Co-SR function is set to be that the number of terminal devices 30 that are detected by the shared AP 20 but are not detected by other shared APs 20 is two or more. Hereinafter, the terminal devices 30 detected by the shared AP 20 will be referred to as "detected terminals."

[0087] In this example, the terminals detected by shared AP 20-1 are terminal devices 30-1, 30-2, 30-3, and 30-4. On the other hand, the terminals detected by shared AP 20-2 are terminal devices 30-3, 30-4, 30-5, and 30-6. In this case, terminal devices 30-3 and 30-4 overlap among the terminals detected by shared APs 20-1 and 20-2. Therefore, of the terminal devices 30 detected by shared AP 20-1, the number of terminal devices 30 that have not been detected by other shared APs 20-2 is two (terminal devices 30-1 and 30-2). Similarly, of the terminal devices 30 detected by shared AP 20-1, the number of terminal devices 30 that have not been detected by other shared APs 20-2 is two (terminal devices 30-5 and 30-6).

[0088] The sharing AP 10 can ascertain the number of undetected terminals for each shared AP 20 based on the information about detected terminals notified by the shared APs 20-1 and 20-2. In this example, because the number of undetected terminals for each shared AP 20 is two or more, the sharing AP 10 instructs each of the shared APs 20-1 and 20-2 to enable the Co-SR function. Then, each of the shared APs 20-1 and 20-2 begins using the Co-SR function. In this way, the sharing AP 10 can determine whether to use the Co-SR function based on the number of terminal devices 30 that the shared AP 20 has detected but that have not been detected by the other shared APs 20.

[0089] In other words, the sharing AP 10 compares the number of terminal devices 30 that can be detected for each shared AP 20. Then, the sharing AP 10 determines the imbalance in the placement of the terminal devices 30, and if the imbalance exceeds a certain threshold, that is, if a number of terminal devices 30 equal to or greater than the threshold cannot detect each other, the sharing AP 10 determines to enable the Co-SR function.

[0090] The shared AP 20 may determine, based on the received power value, whether or not it has detected the terminal device 30. For example, the shared AP 20 may treat the source of a signal whose preamble has been successfully demodulated with a received power of −62 dBm or more as the detected terminal device 30.

[0091] <1-3> Advantages of the First Embodiment As described above, in the communication system 1 according to the first embodiment, the sharing AP 10 can determine whether to turn the Co-SR function on or off based on information about the subordinate shared APs 20, and can change the settings of the Co-SR function to be applied to the shared APs 20. As a result, the communication system 1 according to the first embodiment can use the Co-SR function efficiently, and can improve the effectiveness of power control.

[0092] <2> Second Embodiment In a communication system 1 according to a second embodiment, a shared AP 20 is configured to control the on / off of the Co-SR function based on information from subordinate terminal devices 30. Details of the communication system 1 according to the second embodiment will be described below, focusing on differences from the first embodiment. Note that the configuration of the communication system according to the second embodiment is the same as that of the first embodiment.

[0093] <2-1> Operation The operation of the communication system 1 according to the second embodiment will be described below.

[0094] <2-1-1> Method for Controlling On / Off of Co-SR Function FIG. 15 is a flowchart showing an example of a method for controlling on / off of the Co-SR function by the shared AP 20 included in the communication system 1 according to the second embodiment.

[0095] The shared AP 20 periodically executes (starts) the series of processes shown in Fig. 15 based on a predetermined schedule, for example. The series of processes shown in Fig. 15 may be started based on a request from the sharing AP 10, a user operation, or a predetermined trigger.

[0096] First, the shared AP 20 acquires information about the subordinate terminal devices 30 (step S20). The details of this information about the subordinate terminal devices 30 will be described later.

[0097] Next, the shared AP 20 determines whether to use the Co-SR function (step S21). Specifically, the determination unit 222 of the shared AP 20 executes a determination process. In the determination process, the determination unit 222 determines whether to set the Co-SR function to ON or OFF, using the information about the subordinate terminal device 30 acquired in the process of step S20 and the pre-set conditions for using the Co-SR function.

[0098] Next, the shared AP 20 checks whether the determination result is different from the current usage status of the Co-SR function (step S22). At this time, the determination unit 222 acquires the current usage status of the Co-SR function from, for example, the link management information 331.

[0099] In the process of step S22, if it is confirmed that the determination result is the same as the current usage status of the Co-SR function (step S22: NO), the shared AP 20 ends the series of processes in Fig. 15 (END). For example, if its own Co-SR function is enabled and the determination result of step S21 indicates that the Co-SR function should be enabled, the shared AP 20 maintains the current setting of its own Co-SR function.

[0100] In the process of step S22, if it is confirmed that the determination result differs from the current usage status of the Co-SR function (step S22: YES), the shared AP 20 notifies the sharing AP 10 of the determination result (step S23). The sharing AP 10, which has been notified of the determination result, updates the usage status of the Co-SR function in the shared AP 20 that sent the determination result.

[0101] After the process of step S23, the shared AP 20 sets the Co-SR function based on the determination result (step S14). Then, the shared AP 20 ends the series of processes shown in Fig. 15 (end). For example, if the shared AP 20's own Co-SR function is in the OFF state and the determination result of step S21 indicates that the Co-SR function should be turned ON, the shared AP 20 sets its own Co-SR function to the ON state by the process of step S24.

[0102] <2-1-2> Method for collecting information used to set the Co-SR function Figure 16 is a schematic diagram showing an example of a method for acquiring information used to determine whether the Co-SR function is on or off in the communication system 1 according to the second embodiment.

[0103] 16, the shared AP 20 transmits a wireless frame including a request to the subordinate terminal device 30 in order to collect information used to set the Co-SR function. In response to the received request, the subordinate terminal device 30 notifies the shared AP 20 of information used to determine whether to turn the Co-SR function on or off. The shared AP 20 may store the request in a beacon signal transmitted by multicast or broadcast, or may transmit the request to each terminal device 30.

[0104] The terminal device 30 may store information used to determine whether to enable or disable the Co-SR function in an element added to an action frame, a beacon frame format, etc. By notifying the information via such a wireless frame, the terminal device 30 can indicate to the shared AP 20 its intention to use the Co-SR function.

[0105] The terminal device 30 may add a block or element for notifying information to the trigger frame or BlockAck and transmit the added block or element. The terminal device 30 may also be configured to voluntarily notify the shared AP 20 of information. In this case, the shared AP 20 may omit sending a request to the terminal device 30 for notifying the information.

[0106] <2-1-3> Conditions for Using the Co-SR Function Figure 17 is a schematic diagram for explaining conditions for using the Co-SR function in the communication system according to the second embodiment. The condition for using the Co-SR function in the second embodiment is, for example, whether the number of terminal devices 30 that wish to use the Co-SR function is equal to or greater than a predetermined number. In the example shown in Figure 17, the condition for using the Co-SR function is set to whether the number of terminal devices 30 that wish to use the Co-SR function is equal to or greater than three.

[0107] In this example, each of the terminal devices 30-1, 30-2, and 30-3 connected to the shared AP 20-1 indicates an intention to use the Co-SR function ("O" in FIG. 17). Therefore, the shared AP 20-1 voluntarily starts using the Co-SR function. On the other hand, each of the terminal devices 30-4, 30-5, and 30-6 connected to the shared AP 20-2 does not indicate an intention to use the Co-SR function. In this case, the shared AP 20-2 disables the Co-SR function.

[0108] In this way, the shared AP 20 can determine whether to use the Co-SR function based on the number of terminal devices 30 that wish to use the Co-SR function, without relying on instructions from the sharing AP 10. In the conditions for using the Co-SR function in the second embodiment, each terminal device 30 may notify the shared AP 20 of binary information indicating whether or not it wishes to use the Co-SR function. Alternatively, each terminal device 30 may notify the shared AP 20 of its intention to use the Co-SR function with a value greater than two. For example, the degree of request for the Co-SR function is indicated on a four-level scale from 0 to 3. In this case, the shared AP 20 determines whether to use the Co-SR function based on, for example, the total degree of request for the Co-SR function of the terminal devices 30 under its control and a predetermined threshold.

[0109] The shared AP 20 may acquire information used to determine whether to use the Co-SR function only from a specific terminal device 30. In this case, the shared AP 20 determines whether to use the Co-SR function based on the information acquired from the specific terminal device 30. For example, the shared AP 20 designates a terminal device 30 that is about to perform transmission by beamforming as the terminal device 30 to be used in determining whether to use the Co-SR function. Furthermore, the terminal device 30 may voluntarily transmit information used to determine whether to use the Co-SR function to the shared AP 20.

[0110] As described above, the shared AP 20 may determine whether to use the Co-SR function separately from the setting of the Co-SR function set by the sharing AP 10. For example, even if the shared AP 20 is not instructed to use the Co-SR function by the sharing AP 10, the shared AP 20 may use the Co-SR function if the above-mentioned usage conditions are met. Note that, when setting the on / off status of the Co-SR function, the determination result by the sharing AP 10 may take priority, or the determination result by the shared AP 20 may take priority.

[0111] <2-2> Effects of the Second Embodiment In the communication system 1 according to the second embodiment, the shared AP 20 can determine whether to turn on or off the Co-SR function and change the settings of the Co-SR function applied to itself based on information from the subordinate terminal devices 30. As a result, the communication system 1 according to the second embodiment can use the Co-SR function efficiently and improve the effectiveness of power control.

[0112] <3> Others In the above embodiment, the sharing AP 10 may set the on / off of the Co-SR function of all of the subordinate shared APs 20 to the same setting, or may set it individually. The above embodiment illustrates a case in which each terminal device 30 establishes a multi-link with one shared AP 20, but this is not limited to this. The method for controlling the on / off of the Co-SR function described in the above embodiment can also be executed in a similar manner when the terminal device 30 is connected to a multi-AP. Furthermore, the terminal device 30 connected to the shared AP 20 may be a single-link device. Both single-link devices and multi-link devices may be connected to the shared AP 20. The determination unit 133 of the sharing AP 10 may determine whether to use the Co-SR function based on information about the terminal device 30 received via the subordinate shared AP 20.

[0113] FIG. 18 is a block diagram showing an example of the configuration of a communication system according to a modification of the first embodiment. As shown in FIG. 18, the communication system 1 may include multiple sharing APs 10 connected via a network NW. In this example, a sharing AP 10-1 and a sharing AP 10-2 are connected via the network NW. The multiple sharing APs 10 may be connected to each other via a wired or wireless connection. The determination unit 133 of one sharing AP 10 may exchange information about the shared APs 20 managed by each sharing AP 10 and information about the determination results of the on / off status of the Co-SR function. As a result, the communication system 1 according to the modification of the first embodiment can coordinate the multiple sharing APs 10 to control the on / off status of the Co-SR function of the shared APs 20 subordinate to each sharing AP 10.

[0114] The conversion process from radio frames to radio signals described in the above embodiments includes, for example, convolutional coding, interleaving, subcarrier modulation, inverse fast Fourier transform, OFDM modulation, and frequency conversion. The conversion process from radio signals to radio frames described in the above embodiments includes, for example, frequency conversion, OFDM demodulation, fast Fourier transform, subcarrier demodulation, deinterleaving, and Viterbi decoding. In this specification, a BlockAck may be referred to as a receipt confirmation frame. A BlockAck request may be referred to as a receipt confirmation request frame.

[0115] In the above embodiment, the CPU 11 of the sharing AP 10, the CPU 21 of the shared AP 20, and the CPU 31 of the terminal device 30 may each be other circuits. For example, the sharing AP 10, the shared AP 20, and the terminal device 30 may each include an MPU (Micro Processing Unit) instead of a CPU. Each of the processes described in the above embodiment may be realized by dedicated hardware. The processes of the sharing AP 10, the shared AP 20, and the terminal device 30 may be a mixture of processes executed by software and processes executed by hardware, or may be only one of them. The CPU may be called a "processor." The wireless communication module may be called a "communication circuit."

[0116] In the above-described embodiment, the flowcharts used to explain the operations are merely examples. The order of the operations described in the embodiment may be changed to the extent possible, or other processes may be added. For example, the order of steps S13 and S14 shown in FIG. 9 may be changed. Similarly, the order of steps S23 and S24 shown in FIG. 15 may be changed. A wireless communication standard other than the IEEE 802.11 standard may be used as the wireless communication standard.

[0117] The present invention is not limited to the above-described embodiments, and various modifications can be made in the implementation stage without departing from the spirit of the invention. Furthermore, the embodiments may be implemented in appropriate combinations, in which case the combined effects can be obtained. Furthermore, the above-described embodiments include various inventions, and various inventions can be extracted by combining selected elements from the disclosed elements. For example, if the problem can be solved and the desired effect can be obtained even if some elements are deleted from all elements shown in the embodiments, the configuration from which these elements are deleted can be extracted as an invention.

[0118] DESCRIPTION OF SYMBOLS 1...Communication system 10...Sharing access point 20...Shared access point 30...Terminal device 11, 21, 31...CPU 12, 22, 32...ROM 13, 23, 33...RAM 14, 24, 34...Wireless communication module 15...Wired communication module 35...Display 36...Storage 110, 310...LLC processing unit 120, 240, 320...Data processing unit 130, 220, 330...Management unit 131...Multi-AP management information 132, 221...Link management information 133, 222...Determination unit 140, 230-1, 230-2, 340...Frame processing unit 300...Application execution unit 351...MAC frame generation unit 352...Transmission / reception unit 353...MAC frame processing unit

Claims

1. An access point comprising: a communication circuit configured to be communicable with a plurality of access points; and a processor configured to determine whether each of the plurality of access points uses a spatial reuse function based on information of each of the plurality of access points, and apply a setting of the spatial reuse function based on a result of the determination to the plurality of access points.

2. The access point according to claim 1, wherein the processor is further configured to determine whether to use the spatial reuse function according to the number of access points among the plurality of access points that desire to use the spatial reuse function.

3. The access point according to claim 1, wherein the processor is further configured to determine whether to use the spatial reuse function according to a distance between two adjacent access points among the plurality of access points.

4. The access point according to claim 3, wherein the processor is further configured to determine whether to use the spatial reuse function according to the number of access points among the plurality of access points that use beamforming.

5. The access point according to claim 1, wherein the plurality of access points includes a first access point and a second access point, and the processor is further configured to determine whether to use the spatial reuse function according to the number of terminal devices detected by the first access point that are not detected by the second access point.

6. An access point in a communication system configured to transfer data via the access point between a terminal device under the access point and another access point, the access point comprising: a communication circuit configured to be communicable with each of the other access point and a plurality of terminal devices; and a processor configured to determine whether to use a spatial reuse function based on information of each of the plurality of terminal devices, and apply a setting of the spatial reuse function based on a result of the determination.

7. The processor is further configured to determine whether to use the space reuse function according to the number of terminal devices among the plurality of terminal devices that desire to use the space reuse function. The access point according to claim 6.

8. The processor is further configured to notify the access point of the setting of the space reuse function based on the result of the determination when the current setting of the space reuse function is different from the setting of the space reuse function based on the result of the determination. The access point according to claim 6.

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