Access point and terminal device

Abstract

An access point according to an embodiment comprises a communication circuit and a processor. The communication circuit is configured to transmit and receive wireless signals. The processor is configured to use the communication circuit to establish a link between a plurality of access points and a terminal device by linking a plurality of access points different from a host station, allocate one access point among the plurality of access points for which the link has been established to the terminal device as a primary access point, and allocate the remaining access points to the terminal device as secondary access points.

Description

Access point and terminal device

[0001] The embodiments relate to an access point and a terminal device.

[0002] A wireless local area network (LAN) is known as a communication system that wirelessly connects an access point (AP) and a terminal device. The terminal device can access a network via an access point within a communication area of ​​the wireless LAN.

[0003] IEEE 802.11bn is considering a multi-AP function in which multiple access points operate in cooperation. One form of the multi-AP function is a system in which 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, in which traffic is distributed 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 in a terminal device that manages wireless connections, etc., using the multi-AP function.

[0004] In the current multi-AP configuration, all second access points to which a terminal device belongs are treated equally. Also, in IEEE 802.11be multi-link communication, when a terminal device and an access point communicate via multiple links, the multiple links are treated equally.

[0005] IEEE 802.11be / D6.0, "35.3 Multi-link operation (MLO)", p.517-614, May 2024

[0006] However, if multiple access lines (multiple second access points or multiple links) are all treated equally, management information, control information, etc. will be transmitted using all of the multiple access lines, which will result in more management information, control information, etc. being transmitted than necessary, resulting in unnecessary consumption of access line resources.

[0007] SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide an access point and a terminal device that can realize efficient communication by changing the way a plurality of access lines are handled.

[0008] An access point according to an embodiment includes a communication circuit and a processor. The communication circuit is configured to transmit and receive wireless signals. The processor is configured to use the communication circuit to link multiple access points different from the access point itself to establish links between the multiple access points and a terminal device, assign one of the multiple access points with which the links are established as a primary access point to the terminal device, and assign the other access points as secondary access points to the terminal device.

[0009] According to the embodiment, it is possible to provide an access point and a terminal device that can improve communication efficiency.

[0010] FIG. 1 is a block diagram showing an example of the overall configuration of a communication system according to an embodiment. FIG. 2 is a block diagram showing an example of the hardware configuration of a shared access point included in the communication system according to an 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 an 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 an embodiment. FIG. 5 is a block diagram showing an example of the functional configuration of a shared access point included in the communication system according to an 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 an 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 an embodiment. FIG. 8 is a flowchart showing an example of a sequence for establishing a multi-AP connection in the communication system according to an embodiment. FIG. 9 is a schematic diagram showing a specific example of a multi-AP connection in the communication system according to an embodiment. FIG. 10 is a time chart showing an example of the frequency at which beacon signals are transmitted on the primary links of a primary access point and a secondary access point in the communication system according to an embodiment. FIG. 11 is a schematic diagram showing an example of the format of a normal beacon used in the communication system according to an embodiment. FIG. 12 is a schematic diagram showing an example of the format of a restriction information beacon used in the communication system according to an embodiment.

[0011] Hereinafter, embodiments will be described with reference to the drawings. The embodiments illustrate devices and methods for embodying the technical ideas of the invention. The drawings are schematic or conceptual. Components having substantially the same functions and configurations are assigned the same reference numerals. Numbers following letters constituting reference numerals are used to distinguish between elements that are referred to by reference numerals containing the same letters and have similar configurations. Similarly, "hyphen + number" following numbers constituting reference numerals is used to distinguish between elements that are referred to by reference numerals containing the same number and have similar configurations.

[0012] In the communication system 1 according to the embodiment, the concepts of a primary access point and a secondary access point, and a primary link and a secondary link are introduced in a multi-AP connection. Hereinafter, "access point" will be abbreviated as "AP" as appropriate. A wireless LAN access point may also be called a "base station." Hereinafter, a first access point in the multi-AP function will be called a "sharing access point." A sharing access point may also be called a "central control device." Hereinafter, a second access point in the multi-AP function will be called a "shared access point."

[0013] <1> Configuration <1-1> Configuration First, a configuration of a communication system 1 according to an embodiment will be described. The following description will be given on the assumption that a multi-AP connection using a multi-AP function has been established in the communication system 1.

[0014] 1 is a block diagram showing an example of the overall configuration of a communication system 1 according to an 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.

[0015] 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.

[0016] 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 separate 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. FIG. 1 shows two shared APs 20-1 and 20-2 connected to the sharing AP 10. Note that the shared AP 20 and the sharing AP 10 may be connected by wire.

[0017] 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.

[0018] In the communication system 1, when a multi-AP connection is established, 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 simultaneously establish a comprehensive connection between the sharing AP 10 and the non-AP_MLD, targeting the multiple shared APs 20 and the multiple affiliated STAs. Note that in a multi-AP connection, the terminal device 30 may establish a multi-link with the shared AP 20.

[0019] 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.

[0020] <1-1-2> Hardware Configuration of Communication System 1 Hereinafter, the hardware configuration of the communication system 1 according to the embodiment will be described.

[0021] 2 is a block diagram showing an example of a hardware configuration of the sharing AP 10 included in the communication system 1 according to the 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.

[0022] 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.

[0023] 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 both the network NW and the shared AP 2, 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.

[0024] 3 is a block diagram showing an example of a hardware configuration of the shared AP 20 included in the communication system 1 according to the 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.

[0025] 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.

[0026] 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. When the shared AP 20 is connected to the sharing AP 10 via a wired connection, 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 wired connection and a shared AP 20 connected to the sharing AP 10 wirelessly.

[0027] 4 is a block diagram showing an example of a hardware configuration of the terminal device 30 included in the communication system 1 according to the 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.

[0028] 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.

[0029] 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.

[0030] <1-1-3> Functional Configuration of Communication System 1 The functional configuration of the communication system 1 according to the embodiment will be described below.

[0031] (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 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.

[0032] The LLC processing unit 110 generates LLC packets by, for example, adding a DSAP (Destination Service Access Point) header, an SSAP (Source Service Access Point) header, etc. 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.

[0033] 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."

[0034] The management unit 130 establishes a wireless connection (wireless link) with the non-AP_MLD of the terminal device 30, maps data types to links, sets up BlockAck, and so on. 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, if 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.

[0035] Furthermore, the management unit 130 assigns multiple shared APs 20 used in a multi-AP connection to a primary access point (hereinafter referred to as a P-AP or primary AP) or a secondary access point (hereinafter referred to as an S-AP or secondary AP). In a multi-AP connection, the management unit 130 assigns one shared AP 20 to the primary AP and the other shared APs 20 to the secondary APs. The management unit 130 may be configured to separately set the frequency and content of frames transmitted and received by the primary AP and the frequency and content of frames transmitted and received by the secondary AP. Details of the functions assigned to the primary AP and secondary AP will be described later.

[0036] The management unit 130 also includes, for example, multi-AP management information 131 and link management information 132. 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 links established in the multi-AP connection.

[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)".

[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-to-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 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 and the non-AP MLD of the terminal device 30 in the multi-AP connection. Furthermore, based on notifications from the sharing AP 10, the management unit 220 generates and distributes beacons necessary for the multi-AP connection, and manages the status of the wireless link between the shared AP 20 and the affiliated STA of the terminal device 30 in the multi-AP connection. The management unit 220 also manages whether its own station is a primary AP or a secondary AP. The management unit 220 has a function of determining the type and content of frames to be transmitted for each link.

[0047] Furthermore, when multiple links are established between the shared AP 20 and the terminal device 30, the management unit 130 assigns one link to a primary link and the other links to secondary links. When a single link is established between the shared AP 20 and the terminal device 30, this link is used in the same way as the primary link, for example. Details of the functions assigned to the primary link and the secondary link will be described later. Furthermore, the management unit 220 includes, for example, link management information 221 and a beacon generation unit 222.

[0048] The link management information 221 stores management information related to 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 can store information included in the multi-AP management information 131 and the link management information 132. The management unit 220 uses the link management information 221 to manage the validity and invalidity of wireless links.

[0049] The beacon generation unit 222 generates a beacon frame or the like including information related to the multi-AP connection based on, for example, management information received from the sharing AP 10. The beacon generation unit 222 notifies the terminal device 30 of the generated beacon frame via the frame processing unit 230-1 and the transmission / reception unit 210-1. The beacon frame includes, for example, information about the sharing AP 10, information about the shared AP 20 of the own station, and information about the shared APs 20 of the other stations included in the multi-AP connection. The beacon frame may also include multi-AP management information 131 and link management information 132 transferred from the sharing AP 10. The beacon frame may be transmitted by broadcast or multicast.

[0050] 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.

[0051] 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.

[0052] 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.

[0053] (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 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 transceiver unit 350. The transceiver unit 350 includes a plurality of affiliated STAs including 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. The transceiver unit 350 is a functional block that executes 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.

[0054] 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.

[0055] 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).

[0056] 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.

[0057] 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 may acquire management information from, for example, a beacon received from the shared AP 20. The management unit 330 also manages information related to the allocation of primary APs and secondary APs in a multi-AP connection. The management unit 330 also manages the status of wireless links between multiple shared APs 20 used in the multi-AP connection and multiple affiliated STAs used in the multi-AP connection. For example, the management unit 330 manages whether the link used is a primary link or a secondary link for each shared AP 20 to which it is connected. The management unit 330 includes, for example, link management information 331.

[0058] 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.

[0059] 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 the multiple affiliated STAs in the transceiver unit 350 in accordance with traffic allocation. Furthermore, when a MAC frame is input from one of the multiple affiliated STAs, 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 one of the multiple affiliated STAs, 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 one of the multiple affiliated STAs. When a management frame or control frame addressed to the frame processing unit 340 is input from one of the multiple affiliated STAs, the frame processing unit 340 outputs the input frame to the management unit 330.

[0060] Each affiliated STA (A-STA) 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 wirelessly connected shared AP 20 via wireless communication. The affiliated STA generates a wireless frame by adding a preamble, etc. to the MAC frame input from the frame processing unit 340. The affiliated STA then converts the generated wireless frame into a wireless signal. The affiliated STA then transmits (radiates) the converted wireless signal via an antenna to the wirelessly connected shared AP 20. The affiliated STA also converts the wireless signal received from the wirelessly connected shared AP 20 via the antenna into a wireless frame. The affiliated STA extracts a MAC frame from the converted wireless frame and outputs the extracted MAC frame to the frame processing unit 340.

[0061] <2> Operation Next, the operation of the communication system 1 according to the embodiment will be described.

[0062] 8 is a flowchart showing an example of a sequence for establishing a multi-AP connection in the communication system 1 according to the embodiment. Hereinafter, an example of the sequence for establishing a multi-AP connection will be described with reference to FIG.

[0063] First, a multi-AP connection request is issued by the terminal device 30 and transferred to the sharing AP 10 via the shared AP 20 (ST1).

[0064] When the sharing AP 10 receives the multi-AP connection request, it executes a multi-AP connection setup operation (ST2). In the multi-AP connection setup operation, association processing and the like are executed between the multiple shared APs 20 used for the multi-AP connection and the terminal device 30.

[0065] After the multi-AP connection setup operation, the sharing AP 10 determines the primary AP and secondary AP (ST3). For example, the sharing AP 10 assigns the primary AP and secondary AP based on information collected during the multi-AP connection setup. The sharing AP 10 then notifies each shared AP 20 used in the multi-AP connection of the determined primary AP and secondary AP information. The sharing AP 10 can individually set the primary AP and secondary AP for each terminal device 30. That is, each shared AP 20 may function as both a primary AP and a secondary AP.

[0066] Thereafter, each shared AP 20 determines a primary link and a secondary link (ST4). Then, each shared AP 20 notifies information about the determined primary link and secondary link to the terminal device 30 that is the target of the multi-AP connection. Note that if the connection between the shared AP 20 and the terminal device 30 is a single link, the processing of step ST4 can be omitted.

[0067] Note that the above description has been given of the case where the sharing AP 10 determines the primary AP and secondary AP for each terminal device 30, i.e., the case where the sharing AP 10 performs centralized control, but the present invention is not limited to this. The function of determining the primary AP and secondary AP for each terminal device 30 may be installed in the shared AP 20. That is, the shared AP 20 may be configured to assign the primary AP and secondary AP to each terminal device 30 by autonomous distributed control. In this case, the sharing AP 10 receives information from each shared AP 20 indicating whether it is the primary AP or the secondary AP, and manages the primary AP and secondary AP in the multi-AP connection.

[0068] Although the above description has been given of an example in which the process of step ST2 and the processes of steps ST3 and ST4 are separate, the present invention is not limited to this. The multi-AP connection setup operation may include the processes of steps ST3 and ST4.

[0069] <2-2> Communication Method Hereinafter, a communication method in the communication system 1 according to the embodiment will be described using a specific example.

[0070] (1: Specific Example of Multi-AP Connection) Fig. 9 is a schematic diagram showing a specific example of multi-AP connection in a communication system according to an embodiment. As shown in Fig. 9, in this example, a terminal device 30-1 establishes a multi-AP connection with a sharing AP 10 using shared APs 20-1 and 20-2, and a terminal device 30-2 establishes a multi-AP connection with the sharing AP 10 using shared APs 20-2 and 20-3. In Fig. 9, a two-dot chain line indicates a primary link (PL), and a dashed line indicates a secondary link (SL).

[0071] The terminal device 30-1 has established three links L1 to L3 with the shared AP 20-1, and two links L4 and L5 with the shared AP 20-2. In the terminal device 30-1, the links L1 and L4 are set as primary links, and the links L2, L3, and L5 are set as secondary links. In the terminal device 30-1, the shared AP 20-1 is set as the primary AP (P-AP), and the shared AP 20-2 is set as the secondary AP (S-AP).

[0072] The terminal device 30-2 has established two links L1 and L2 with the shared AP 20-2, and three links L3 to L5 with the shared AP 20-3. In the terminal device 30-2, links L1 and L3 are set as primary links, and links L2, L4, and L5 are set as secondary links. In the terminal device 30-2, the shared AP 20-2 is set as the primary AP (P-AP), and the shared AP 20-3 is set as the secondary AP (S-AP).

[0073] Thus, in this example, the shared AP 20-2 functions as a primary AP for the terminal device 30-1 and as a secondary AP for the terminal device 30-2. Only one primary AP is assigned to each terminal device 30. On the other hand, multiple secondary APs may be assigned to each terminal device 30, and may be one or more. When a multi-link is established between the shared AP 20 and the terminal device 30, the multi-link may include only one primary link and one or more secondary links.

[0074] The primary link of the primary AP (e.g., link L1 of terminal device 30-1 and link L1 of terminal device 30-2) is used, for example, to transmit normal beacons. Normal beacons correspond to beacon frames used to broadcast various information in wireless communication. The primary link of the primary AP may be used to transmit management frames or control frames, not limited to beacons, or may be used to transmit limited information beacons. Limited information beacons correspond to normal beacons with reduced information. Specifically, the primary link of the primary AP may be used for communications such as information regarding TID allocation, identification information for the primary AP and secondary AP, identification information for the primary link and secondary link, switching-related information such as roaming, implementation of agreements required for multi-AP cooperation, and implementation of proxy processing for TXOP sharing and NAV (Network Allocation Vector: transmission prohibition period) setting.

[0075] The primary link of the secondary AP (e.g., link L4 of terminal device 30-1 and link L1 of terminal device 30-2) is used, for example, to transmit a limited information beacon. The limited information beacon includes, for example, primary link identification information. The secondary link of the primary AP (e.g., links L2 and L3 of terminal device 30-1 and link L2 of terminal device 30-2) and the secondary link of the secondary AP (e.g., link L5 of terminal device 30-1 and links L4 and L5 of terminal device 30-2) are each used, for example, to transmit application data.

[0076] (2: Beacon Frame Transmission Frequency) Fig. 10 is a time chart showing an example of the beacon frame transmission frequency in the primary links of the primary access point and the secondary access point in the communication system 1 according to the embodiment. Fig. 10 shows an example of the beacon frame transmission timing in each of the link L1 corresponding to the primary link PL of the primary AP for the terminal device 30-1 and the link L4 corresponding to the primary link PL of the secondary AP for the terminal device 30-1 in the state shown in Fig. 9.

[0077] 10 , a normal beacon BE is transmitted in a cycle F1 on a link L1 corresponding to the primary link PL of the primary AP. On the other hand, a restriction information beacon LBE is transmitted in a cycle F2, which is longer than the cycle F1, on a link L4 corresponding to the primary link PL of the secondary AP. In this way, in the communication system 1 according to the embodiment, the transmission frequency of a beacon signal on the primary link PL of the secondary AP is set lower than the transmission frequency of a beacon signal on the primary link PL of the primary AP. The transmission frequency of a beacon frame on the primary link PL of the secondary AP can be set individually for each link and each secondary AP.

[0078] An opportunity to transmit the restriction information beacon LBE may be set in the primary link PL of the primary AP. The timing at which the primary link PL of the primary AP transmits the restriction information beacon LBE may be set by replacing the normal beacon BE in the transmission cycle of the normal beacon BE. Furthermore, the restriction information beacon LBE in the primary link PL of the primary AP may be transmitted at a timing different from that of the normal beacon BE.

[0079] (3: Specific example of normal beacon) Fig. 11 is a schematic diagram showing an example of the frame format of a normal beacon used in the communication system 1 according to the embodiment. As shown in Fig. 11, a normal beacon includes, for example, a frame control field, a duration field, an address field, a frame body field, a padding field, and an FCS (Frame Check Sequence) field. Note that the configuration of a beacon frame is not limited to this. A beacon frame may not include some or all of the fields described below, and may include fields that have different names but the same functions as the fields described below.

[0080] The frame control field stores various control information. The frame control field includes, for example, information indicating the frame type of the wireless frame. The duration field includes information indicating the planned period for using the wireless link. The address field includes information indicating the BSSID (Basic service set identifier), source address, destination address, sender terminal address, receiver terminal address, etc. The frame body field includes information related to multi-AP communication, such as first information and second information. The padding is an area for adjusting the data length of the wireless frame. The FCS field stores an error detection code for the MAC header and frame body field pair, and is used to determine whether or not there is an error in the data frame.

[0081] (4: Specific example of restriction information beacon) Figure 12 is a schematic diagram showing an example of the format of a restriction information beacon used in the communication system 1 according to the embodiment. As shown in Figure 11, the information stored in the frame body field of a control information beacon is different from that of a normal beacon, for example. For example, the frame body field of a control information beacon stores first information but does not include second information. In this way, a restriction information beacon has a configuration in which some information is omitted from a normal beacon, for example. For this reason, the frame size of a control information beacon is smaller than the frame size of a normal beacon.

[0082] <3> Effects of the embodiment As described above, the communication system 1 according to the embodiment distinguishes between the multiple shared APs 20 used in a multi-AP configuration and treats them as primary APs and secondary APs. Furthermore, the communication system 1 distinguishes between the links used in a multi-link configuration, such as primary links and secondary links. Furthermore, the primary link of the primary AP is responsible for sending and receiving basic management information and control information. In other words, the primary AP is the main controller for each terminal device 30. The secondary AP and secondary link are assigned auxiliary roles to the primary AP and primary link, respectively.

[0083] This allows the communication system 1 to determine the information, data, etc. to be transmitted via the primary link or primary AP according to the characteristics of the transmission content. Furthermore, the communication system 1 can achieve more efficient communication by setting the content of frames to be transmitted and received and the frequency of frame transmission differently between the primary and secondary. Therefore, the communication system 1 according to the embodiment can improve communication efficiency.

[0084] <4> Others 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. A wireless communication standard other than the IEEE 802.11 standard may be used as the wireless communication standard.

[0085] In the above embodiments, each of the CPUs 11, 21, and 31 may be other circuits. For example, instead of a CPU, an MPU (Micro Processing Unit) or the like may be provided. Each of the processes described in each embodiment may be realized by dedicated hardware. Each of the processes described in the above embodiments may be a mixture of processes executed by software and processes executed by hardware, or may be only one of them.

[0086] 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.

[0087] 1...Communication system 10...Sharing AP 20, 20-1, 20-2...Shared AP 30, 30-1, 30-2...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, 331...Link management information 140, 230-1, 230-2, 340...Frame processing unit 150, 210-1, 210-2, 350...Transmission / reception unit 222...Beacon generation unit 300...Application execution unit

Claims

1. An access point comprising: a communication circuit configured to transmit and receive wireless signals; and a processor configured to use the communication circuit to establish links between a plurality of access points different from the access point itself and a terminal device by coordinating the plurality of access points, and to assign one of the plurality of access points with which the links have been established to the terminal device as a primary access point, and to assign the other access points to the terminal device as secondary access points.

2. The access point of claim 1, wherein the processor is further configured to set the frequency and content of frames transmitted and received at the primary access point and the frequency and content of frames transmitted and received at the secondary access point separately.

3. An access point comprising: a communication circuit configured to transmit and receive wireless signals; and a processor configured to use the communication circuit to establish links between a plurality of access points including the access point itself and a terminal device, and to assign one of the plurality of access points with which the links have been established to the terminal device as a primary access point, and to assign the other access points to the terminal device as secondary access points.

4. The access point of claim 3, wherein the processor is further configured to assign one access point of the plurality of access points as the primary access point and assign other access points as the secondary access points.

5. The access point according to claim 3, wherein the processor is further configured to, when multiple links are established with the terminal device, assign one of the multiple links as a primary link and assign the other links as secondary links.

6. The access point of claim 3, wherein the processor transmits first frames to the terminal device at a first frequency when assigned to the primary access point, and transmits second frames, having a size smaller than the first frames, to the terminal device at a second frequency different from the first frequency when assigned to the secondary access point.

7. A terminal device comprising: a communication circuit configured to transmit and receive wireless signals; and a processor configured to establish communication with a plurality of access points using the communication circuit, wherein one access point among the plurality of access points is assigned as a primary access point and the other access points are assigned as secondary access points; and the processor is configured to receive, via the communication circuit, a first frame from the primary access point at a first frequency and a second frame from the secondary access point at a second frequency different from the first frequency.

8. The terminal device according to claim 7, wherein the second frame includes a portion of the information stored in the first frame, and the frame size of the first frame is different from that of the second frame.

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