Shared access point, shared access point, and terminal device

Abstract

A shared access point according to an embodiment includes a first management unit. A shared access point is included in a communication system provided with: a shared access point including a second management unit and a first wireless signal processing unit; another shared access point including a third management unit and a second wireless signal processing unit; and a terminal device including a fourth management unit and third and fourth wireless signal processing units. The first management unit establishes a first wireless link between the first and third wireless signal processing units and a second wireless link between the second and fourth wireless signal processing units, and transmits and receives frames between the first management unit and the third management unit via the first wireless link. The setting of a service period in which frame exchange of traffic can be preferentially performed for the first wireless link and the second wireless link is established in batches, and the start time of the service period is notified to the second management unit and the third management unit, respectively.

Description

Technical Field

[0001] The implementation methods involve a sharing access point, a shared access point, and a terminal device. Background Technology

[0002] Wireless LANs (Local Area Networks) are known as communication systems that wirelessly connect access points (APs) to terminal devices. Terminal devices can access the network via an access point within a communicable area using a wireless LAN. IEEE 802.11be mentions multi-link transmission, which establishes multiple links (transmission paths) between a terminal device and an access point. In multi-link transmission, multiple links can operate independently. Next-generation standards are exploring communication that establishes multiple links between a terminal device and multiple access points, i.e., multi-AP communication.

[0003] Furthermore, as a method for low-latency traffic transmission and reception between an access point and a terminal device, the R-TWT (Restricted Target Wake Time) function is known. Using the R-TWT function, the access point sets a service period according to a period corresponding to the delay required by the low-latency traffic, and notifies the terminal device of the set service period using management frames such as beacons or action frames. Then, during the periodically set service period, the access point prioritizes the transmission and reception of low-latency traffic. This reduces the latency and jitter of low-latency traffic. When the R-TWT function is used in multi-link communication, the content established using one link between the access point and the terminal device can be reflected in the other links constituting the multi-link system.

[0004] Existing technical documents

[0005] Non-patent literature

[0006] Non-patent document 1: IEEE 802.11be D3.0, “35.3.24 TWT operation”, pp. 585-586, January 2023. Summary of the Invention

[0007] The technical problem that the invention aims to solve

[0008] However, in multi-AP communication, the R-TWT function needs to be configured separately for each of the multiple access points connected to the terminal device. Furthermore, in multi-AP communication, if coordinated communication between multiple access points cannot be implemented, it may hinder efficient low-latency data transmission.

[0009] This invention was made in view of the above situation, and its purpose is to provide a wireless communication environment that can efficiently transmit low-latency traffic in multi-AP communication.

[0010] Technical solutions for solving technical problems

[0011] The shared access point in the implementation includes a first management unit. The shared access point is included in a communication system comprising: a shared access point including a second management unit and a first wireless signal processing unit; other shared access points including a third management unit and a second wireless signal processing unit; and a terminal device including a fourth management unit, a third wireless signal processing unit, and a fourth wireless signal processing unit. The first management unit is configured to: establish a first wireless link between the first and third wireless signal processing units and a second wireless link between the second and fourth wireless signal processing units; establish service periods for priority traffic exchange on the first and second wireless links in batches through frame transmission and reception between the first and third management units via the first wireless link; and notify the second and third management units of the start time of each service period.

[0012] Invention Effects

[0013] According to the implementation method, a wireless communication environment that can efficiently transmit low-latency traffic can be provided. Attached Figure Description

[0014] Figure 1 This is a block diagram illustrating an example of the structure of a communication system according to an embodiment.

[0015] Figure 2 This is a block diagram illustrating an example of the hardware structure of a shared access point in a communication system according to an embodiment.

[0016] Figure 3 This is a block diagram illustrating an example of the hardware structure of a shared access point in a communication system according to an embodiment.

[0017] Figure 4 This is a block diagram illustrating an example of the hardware structure of a terminal device included in a communication system according to an embodiment.

[0018] Figure 5 This is a block diagram illustrating an example of the functional structure of a shared access point in a communication system according to an embodiment.

[0019] Figure 6 This is a table illustrating an example of multi-AP management information included in the management unit of a shared access point in a communication system according to an embodiment.

[0020] Figure 7This is a table showing an example of information associated with one affiliated STA in the link management information included in the management unit of the shared access point of the communication system shown in the embodiment.

[0021] Figure 8 This is a block diagram illustrating an example of the functional structure of a shared access point in a communication system according to an embodiment.

[0022] Figure 9 This is a block diagram illustrating an example of the functional structure of a terminal device included in a communication system according to an embodiment.

[0023] Figure 10 This is a flowchart illustrating an example of the operation of a shared access point in a communication system according to an embodiment.

[0024] Figure 11 This is a sequence diagram illustrating an example of the processing from multi-link establishment to the initiation of R-TWT communication in a communication system according to an embodiment.

[0025] Figure 12 This is a timing diagram illustrating an example of R-TWT communication in a communication system according to an embodiment.

[0026] Figure Labels

[0027] 1: Communication system; 10: Shared access point; 30: Terminal device; 20, 20-1, 20-2, 20-3: Shared access point; 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, 320: Data processing unit; 130, 220, 330: Management unit; 131: Multi-AP management information; 132, 221, 331: Link management information; 140, 230, 340: Frame processing unit; 150, 210: Transceiver unit; 222: Beacon generation unit; 240-1~240-3, 350-1~350-3: Wireless signal processing unit; 300: Application execution unit. Detailed Implementation

[0028] The embodiments will now be described with reference to the accompanying drawings. These embodiments illustrate apparatus and methods for embodying the inventive concept. The drawings are schematic or conceptual. In the following description, common reference numerals are used for constituent elements having the same function and structure. Furthermore, when distinguishing multiple constituent elements having the same function and structure, a hyphen followed by a number is appended to the end of the reference numerals.

[0029] <1> structure

[0030] First, the structure of the communication system 1 in the implementation method will be described.

[0031] <1-1> Structure of Communication System 1

[0032] Figure 1 This is a block diagram illustrating an example of the structure of the communication system 1 according to an embodiment. Figure 1 As shown, the communication system 1 includes a shared access point (shared AP) 10, multiple shared access points (shared APs) 20, and a terminal device 30.

[0033] Shared AP 10 is a type of access point (AP) for a wireless LAN. The shared AP is connected to the network NW via wired or wireless means. Shared AP 10 is configured to communicate wirelessly or wirelessly with a server (not shown) on the network NW. Additionally, the shared AP is connected to multiple shared APs 20 via wired or wireless means. Shared AP 10 is configured to communicate wirelessly or via wired means with each of the multiple shared APs 20.

[0034] Each shared AP 20 is a type of access point (AP) for a wireless LAN. Multiple shared APs 20 have identical structures. Each shared AP 20 is configured to communicate wirelessly or wiredly with the shared AP 10 and wirelessly with the terminal device 30. The multiple shared APs 20 are located in mutually separate positions and have distinct communicable areas. Furthermore, the communicable area of ​​each shared AP 20 may overlap with the communicable areas of other shared APs 20.

[0035] The terminal device 30 is a wireless terminal such as a smartphone or a PC (personal computer). The terminal device 30 is wirelessly connected to each shared AP 20. The terminal device 30 is configured to communicate wirelessly with each shared AP 20. The terminal device 30 supports multi-link communication using multiple channels (links). Furthermore, the terminal device 30 only needs to be configured to be included in the communication area of ​​at least one shared AP 20.

[0036] The wireless communication used in Communication System 1 conforms to, for example, the IEEE 802.11 standard. The IEEE 802.11 standard features wireless communication functionality based on the OSI (Open Systems Interconnection) reference model. In the OSI reference model, wireless communication functionality is 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, Layer 7: Application Layer). The Data Link Layer includes the LLC (Logical Link Control) sublayer and the MAC (Media Access Control) sublayer. Frequency bands used in the wireless communication of Communication System 1 may utilize, for example, the 2.4 GHz band, 5 GHz band, 6 GHz band, 45 GHz band, and 60 GHz band. Multiple channels can be allocated to each frequency band.

[0037] (Communication method of communication system 1)

[0038] In communication system 1, shared AP 10, shared AP 20, and terminal device 30 each support multi-link transmission as a communication method. Furthermore, shared AP 10 can utilize multiple shared APs 20 to establish multiple links with terminal device 30, enabling indirect communication with terminal device 30 that has established multiple links. In this specification, the wireless connection method in which terminal device 30 communicates with shared AP 10 via multiple shared APs 20 is referred to as the "multi-AP connection method."

[0039] In the multi-AP connection mode, multiple shared APs 20 belong to a shared AP 10. Figure 1 The example shown illustrates the case where three shared APs 20-1, 20-2, and 20-3 belong to shared AP 10. The following explanation uses the case of three shared APs 20-1, 20-2, and 20-3 belonging to shared AP 10 as an example to illustrate the structure and operation of communication system 1.

[0040] In this example, links (transmission paths) are established between shared AP 10 and terminal device 30 via shared AP 20-1, shared AP 20-2, and shared AP 20-3, respectively. In this case, shared APs 20-1, 20-2, and 20-3 become candidate transit points for data exchange between shared AP 10 and terminal device 30. Then, terminal device 30 performs data exchange with shared AP 10 via one of the shared APs 20-1, 20-2, and 20-3, which are candidate transit points.

[0041] Terminal device 30 includes a non-AP type MLD and multiple auxiliary STAs (A-STAs). The non-AP type MLD is an MLD (multi-link device) that manages the link status and wireless communication of the multiple A-STAs. The non-AP type MLD can also implement multi-link processing for establishing a shared AP 10 and terminal device 30 in a multi-AP connection mode. Each A-STA corresponds to a functional block for establishing a wireless link with the shared AP 20. In this example, terminal device 30 includes a non-AP type MLD #1 as a non-AP type MLD, and A-STA #1, A-STA #2, and A-STA #3 as multiple A-STAs. Different channels or the same channel are assigned to A-STA #1 to #3. A-STA #1 to #3 can utilize the same frequency band or different frequency bands.

[0042] The shared AP 20 includes an AP-type MLD and multiple affiliated APs (A-APs). The AP-type MLD manages the link status and wireless communication of each of the multiple A-APs. The AP-type MLD can also implement processing for establishing multiple links between the shared AP 10 and the terminal device 30 in a multi-AP connection mode. Each A-AP corresponds to a functional block for establishing a wireless link with the terminal device 30. In this example, the shared AP 20-1 includes AP-type MLD#1 as the AP-type MLD, and includes A-AP#1, A-AP#2, and A-AP#3 as multiple A-APs. In this example, the shared AP 20-2 includes AP-type MLD#2 as the AP-type MLD, and includes A-AP#4, A-AP#5, and A-AP#6 as multiple A-APs. In this example, the shared AP 20-3 includes AP-type MLD#3 as the AP-type MLD, and includes A-AP#7, A-AP#8, and A-AP#9 as multiple A-APs.

[0043] Each A-STA can, for example, establish a link with one or more A-APs for each shared AP 20 belonging to shared AP 10. Then, each A-STA is configured to communicate with one of the multiple A-APs with established links (i.e., a valid link). In this example, A-STAs #1 to #3 each establish links with A-APs #1 to #9. Then, the link between A-STA #1 and A-AP #1 is configured as valid, and the links between A-STA #1 and the other A-APs are configured as invalid. The link between A-STA #2 and A-AP #5 is configured as valid, and the links between A-STA #2 and the other A-APs are configured as invalid. The link between A-STA #3 and A-AP #9 is configured as valid, and the links between A-STA #3 and the other A-APs are configured as invalid.

[0044] Furthermore, multiple links can be enabled for a single shared AP 20. Each shared AP 20 can disable all links based on the location of the terminal device 30. Additionally, the non-AP type MLD#1, A-STA#1~#3, AP type MLD#1~#3, and A-AP#1~#9 are each assigned a distinct identifier. Link IDs or MAC addresses can be used as such identifiers. In the following description, non-AP type MLD#1, A-STA#1~#3, AP type MLD#1~#3, and A-AP#1~#9 are referred to as identifiers.

[0045] (R-TWT function)

[0046] In communication system 1, shared AP 10, shared AP 20, and terminal device 30 all support the R-TWT (Restricted Target Wake-up Time) function. The R-TWT function allocates service periods to terminal device 30 to prioritize the exchange of traffic requiring low latency. Hereinafter, the service period set according to the R-TWT function is referred to as the "R-TWT Service Period (R-TWT SP)," and the traffic requiring low latency is referred to as "low-latency traffic."

[0047] When setting up the R-TWT function, the shared AP 10 sets a certain period (TWT period). Preferably, the TWT period is set in conjunction with the transmission period of low-latency traffic. One period of the TWT period (TWT interval) contains an R-TWT SP. The R-TWT SP is determined, for example, based on the TWT start time and the TWT duration. The TWT duration represents the length of the R-TWT SP from the TWT start time. The terminal device 30 can identify the time obtained from the TWT start time and the TWT period as the rTWT start time of the next R-TWT service period SP. The TWT interval also corresponds to the interval between the TWT start times of adjacent R-TWT service period SPs.

[0048] In the R-TWT SP, the shared AP 10 utilizes the shared AP 20 with a valid link to prioritize frame switching opportunities for the terminal device 30. A frame switching opportunity corresponds to the opportunity to send traffic (data) via frame switching. For example, in the R-TWT SP, the terminal device 30 sends low-latency traffic based on the receipt of a trigger frame. In this way, the R-TWT function enables the priority transmission of low-latency traffic from the terminal device 30 in the R-TWT SP, thereby improving the latency performance of low-latency traffic.

[0049] Furthermore, when setting up the R-TWT function, the suppression transmission period can be set overlapping with the R-TWT SP. The suppression transmission period corresponds to the period during which traffic is suppressed from being transmitted by other terminal devices that are not given priority in frame switching opportunities. Additionally, the initial settings for the R-TWT function can be determined using various methods. For example, in the initial settings of the R-TWT function, traffic attributes such as the occurrence interval and data volume of traffic notified from applications generating low-latency traffic can be used. In this case, the shared AP 10 notifies the server on the network NW of the type of traffic, thereby obtaining the corresponding traffic attributes. Then, the shared AP 10 determines the initial settings for the R-TWT function based on the obtained traffic attributes.

[0050] <1-2> Hardware Structure of Communication System 1

[0051] The hardware structure of the communication system 1 according to the embodiment will be described below.

[0052] <1-2-1> Hardware Structure of Shared AP 10

[0053] Figure 2 This is a block diagram illustrating an example of the hardware structure of a shared AP 10 provided in the communication system 1 of the embodiment. Figure 2 The example illustrates the wireless connection between shared AP 10 and each shared AP 20, and the wired connection between shared AP 10 and the network NW. For example... Figure 2 As shown, the shared AP 10 includes, for example, a CPU (Central Processing Unit) 11, a ROM (Read-Only Memory) 12, a RAM (Random Access Memory) 13, a wireless communication module 14, and a wired communication module 15.

[0054] CPU 11 is an integrated circuit capable of executing various programs and controlling the overall operation of the shared AP 10. ROM 12 is, for example, a non-volatile semiconductor memory that stores programs and control data used to control the shared AP 10. RAM 13 is, for example, a volatile semiconductor memory, used as the working area of ​​CPU 11. Wireless communication module 14 is configured to transmit and receive wireless signals via an antenna. Wireless communication module 14 is used for transmitting and receiving data, etc., with each shared AP 20. Wired communication module 15 is a circuit for transmitting and receiving data, etc., via wired signals. Wired communication module 15 is configured to be connected to a network NW.

[0055] Furthermore, the shared AP 10 can have other hardware configurations. For example, when the shared AP 10 is wirelessly connected to both the network NW and the shared AP 20, the wired communication module 15 can be omitted from the shared AP 10. When the shared AP 10 is wiredly connected to both the network NW and the shared AP 20, the wireless communication module 14 can be omitted from the shared AP 10. The antenna can be built into the shared AP 10 or connected externally.

[0056] <1-2-2> Hardware Structure of Shared AP 20

[0057] Figure 3 This is a block diagram illustrating an example of the hardware structure of the shared AP 20 provided in the communication system 1 of the embodiment. Figure 3 The example illustrates a wireless connection between shared AP 10 and shared AP 20. For example... Figure 2 As shown, the shared AP 20 includes, for example, a CPU 21, ROM 22, RAM 23 and a wireless communication module 24.

[0058] CPU 21 is an integrated circuit capable of executing various programs and controlling the overall operation of the shared AP 20. ROM 22 is, for example, a non-volatile semiconductor memory that stores programs and control data used to control the shared AP 20. RAM 23 is, for example, a volatile semiconductor memory and serves as the working area of ​​CPU 21. The wireless communication module 24 is configured to transmit and receive wireless signals via an antenna. The wireless communication module 24 is used for transmitting and receiving data, etc., with the shared AP 10 and with the terminal device 30.

[0059] Furthermore, the shared AP 20 can have other hardware configurations. For example, when the shared AP 20 is wired to the shared AP 10, the same wired communication module 15 as the shared AP 10 can be added to the shared AP 20. The antenna can be built into the shared AP 20 or connected externally.

[0060] <1-2-3> Hardware Structure of Terminal Device 30

[0061] Figure 4 This is a block diagram illustrating an example of the hardware structure of the terminal device 30 included in the communication system 1 of the embodiment. For example... Figure 4 As shown, 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 device 36.

[0062] The CPU 31 is an integrated circuit capable of executing various programs and controlling the overall operation of the terminal device 30. The ROM 32 is, for example, a non-volatile semiconductor memory that stores programs and control data used to control the terminal device 30. The RAM 33 is, for example, a volatile semiconductor memory that serves as the working area of ​​the CPU 31. The wireless communication module 34 is configured to transmit and receive wireless signals via an antenna. The wireless communication module 34 is used for transmitting and receiving data with the shared AP 20. The display 35 is, for example, an LCD (liquid crystal display) or an EL (electroluminescent) display. The display 35 displays, for example, a GUI (graphical user interface) corresponding to the application software. The storage 36 is a non-volatile storage device, for example, storing the system software of the terminal device 30.

[0063] Furthermore, the terminal device 30 can also be other hardware structures. For example, when the terminal device 30 is an IoT (Internet of Things) terminal, the display 35 can be omitted from the terminal device 30. The display 35 can function as an input interface for the terminal device 30. The antenna can be built into the terminal device 30 or connected externally.

[0064] <1-3> Functional Structure of Communication System 1

[0065] The functional structure of the communication system 1 in the following implementation method will be described.

[0066] <1-3-1> Functional Structure of Shared AP 10

[0067] Figure 5 This is a block diagram illustrating an example of the functional structure of a shared access point 10 provided in the communication system 1 of the embodiment. The shared access point 10 functions, for example, as a computer including an LLC processing unit 110, a data processing unit 120, a management unit 130, a frame processing unit 140, and a transceiver unit 150. The LLC processing unit 110 is a functional block that performs processing corresponding to the LLC sublayer of Layer 2 and Layers 3 to 7. The data processing unit 120, management unit 130, and frame processing unit 140 are functional blocks that perform processing corresponding to the MAC sublayer of Layer 2. When the shared access point 10 communicates wirelessly with each shared access point 20, the transceiver unit 150 is a functional block that performs processing corresponding to Layer 1. When the shared access point 10 communicates wiredly with each shared access point 20, the transceiver unit 150 is a functional block that performs processing corresponding to the MAC sublayer of Layer 2.

[0068] LLC processing unit 110, for example, appends DSAP (Destination Service Access Point) headers, SSAP (Destination Service Access Point) headers, etc., to the data received from network NW to generate LLC data packets. Then, LLC processing unit 110 inputs the generated LLC data packets to data processing unit 120. Additionally, LLC processing unit 110 extracts data from the LLC data packets input from data processing unit 120. Then, LLC processing unit 110 sends the extracted data to network NW.

[0069] The data processing unit 120 appends a MAC header to the LLC data packet input from the LLC processing unit 110 to generate a MAC frame. Then, the data processing unit 120 inputs the generated MAC frame to the frame processing unit 140. Additionally, the data processing unit 120 extracts LLC data packets from the MAC frame input from the frame processing unit 140. Then, the data processing unit 120 inputs the extracted LLC data packets to the LLC processing unit 110. Furthermore, the MAC frame containing data is also called a "data frame".

[0070] The management unit 130 controls the establishment of wireless connections (wireless links) between the shared AP 10 and the non-AP type MLD of the terminal device 30 in a multi-AP connection mode. For example, in response to a multi-AP association request from the terminal device 30, the management unit 130 performs multi-AP association processing. For example, when the terminal device 30 uses three A-STAs #1 to #3, through multi-AP association processing, A-STAs #1 to #3 establish wireless links with A-APs #1 to #3 of the shared AP 20-1, A-APs #4 to #6 of the shared AP 20-2, and A-APs #7 to #9 of the shared AP 20-3, respectively. During actual data exchange, the management unit 130 sets any one of the established wireless links to enabled for use as a wireless link for data exchange, and sets the other wireless links to disabled.

[0071] Additionally, the management unit 130 includes multi-AP management information 131 and link management information 132. Multi-AP management information 131 includes information related to the access points used in the multi-AP connection (i.e., shared AP 10 and shared APs 20-1, 20-2, and 20-3) and terminal devices 30. For example, multi-AP management information 131 is set for each terminal device 30 establishing the multi-AP connection. Link management information 132 includes information about the status of the links established in the multi-AP connection and the R-TWT function. Details regarding the respective multi-AP management information 131 and link management information 132 will be described later.

[0072] 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. Alternatively, 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 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 control frame may contain, for example, management information. This management information may include notification information for any device in the shared AP 20 and the terminal device 30, control information regarding the operation of any device in the shared AP 20 and the terminal device 30, etc.

[0073] The transceiver unit 150 transmits and receives data and management information with each of the multiple shared APs 20 belonging to the shared AP 10. In this example, shared APs 20-1, 20-2, and 20-3 are connected to the transceiver unit 150 via wired or wireless means, respectively.

[0074] When the shared AP 10 communicates wirelessly with multiple shared APs 20, the transceiver unit 150 includes one or more wireless signal processing units. Each wireless signal processing unit of the transceiver unit 150 is configured to transmit and receive wireless signals using different frequency bands or channels. Each wireless signal processing unit of the transceiver unit 150 adds a preamble or the like to the MAC frame input from the frame processing unit 140 to generate a wireless frame, and converts the generated wireless frame into a wireless signal. Then, each wireless signal processing unit transmits (radiates) the converted wireless signal to each of the shared APs 20 via an antenna. In addition, each wireless signal processing unit of the transceiver unit 150 converts the wireless signal received from any of the shared APs 20 via the antenna into a wireless frame. Each wireless signal processing unit extracts a MAC frame from the converted wireless frame and outputs the extracted MAC frame to the frame processing unit 140.

[0075] For example, the transceiver unit 150 has one wireless signal processing unit for each of the multiple shared APs 20 belonging to the shared AP 10. Then, the frame processing unit 140 outputs data, etc., to the wireless signal processing unit associated with shared AP 20-1, data, etc., to the wireless signal processing unit associated with shared AP 20-2, and data, etc., to the wireless signal processing unit associated with shared AP 20-3. The transceiver unit 150 can have both a wireless signal processing unit assigned to the transmission and reception of data and a wireless signal processing unit assigned to the transmission of management information.

[0076] When the shared AP 10 communicates with multiple shared APs 20 via wired connections, the transceiver unit 150 is connected to each of the multiple shared APs 20 belonging to the shared AP 10 via a wired network. Then, the transceiver unit 150 sends and receives data and management information between each of the shared APs 20-1 to 20-3 via the wired network. In this case, the transceiver unit 150 is configured with a network interface of the wired network.

[0077] Furthermore, after multiple AP connections are established, the frame processing unit 140 assigns the destination of the MAC frame input from the data processing unit 120 to any one of the multiple shared APs 20-1, 20-2, and 20-3 belonging to the shared AP 10. For example, the frame processing unit 140 outputs the MAC frame to the radio signal processing unit associated with the shared AP 20 among the shared APs 20-1, 20-2, and 20-3 belonging to the shared AP 10 that has been allocated a valid link. The frame processing unit 140 can determine the radio signal processing unit of the MAC frame's output destination based on the TID (Traffic Identifier) ​​associated with the access class. In addition, when the R-TWT agreement is established (described later), the frame processing unit 140 can send information for controlling the R-TWT function to the multiple shared APs 20-1, 20-2, and 20-3 belonging to the shared AP 10.

[0078] Figure 6 This is a table illustrating an example of multi-AP management information 131 included in the management unit 130 of the shared AP 10 of the communication system 1 of the embodiment. (Example) Figure 6 As shown, the multi-AP management information 131 includes, for example, information about the shared AP identifier, TWT protocol capability (TWT AC), STA identifier, and link identifier.

[0079] The shared AP identifier information included in the multi-AP management information 131 includes information about the identifiers of the AP-type MLDs and A-APs assigned to the multi-AP connections. In this example, A-APs #1 to #3 are assigned to the multi-AP connections associated with AP-type MLD #1. A-APs #4 to #6 are assigned to the multi-AP connections associated with AP-type MLD #2. A-APs #7 to #9 are assigned to the multi-AP connections associated with AP-type MLD #3.

[0080] The TWT protocol capability information included in the multi-AP management information 131 is recorded for each link allocated to the multi-AP connection, including, for example, information used as a basis for scheduling R-TWT SPs. A shared AP 10 can, for example, obtain the TWT protocol capability of each link by requesting each shared AP 20. The TWT protocol capability may simply indicate whether an R-TWT SP can be scheduled.

[0081] The link identifier information included in the multi-AP management information 131 includes information about the identifiers of the links established in the multi-AP connection. Shared AP 10, for example, uses link identifiers to manage the activation (enabled) and deactivation (disabled) of links used in the multi-AP connection. In this example, links #1 to #9 are assigned to A-APs #1 to #9 respectively.

[0082] In addition, multi-AP management information can include information about frequency bands, channels, operating parameters, and access categories. Frequency band information indicates the frequency bands used by the A-AP and A-STA for the wireless link. Channel information indicates the channels used by the A-AP and A-STA for the wireless link. Operating parameter information includes, for example, CWmin, CWmax, AIFS (Arbitration Inter-Frame Spacing), and TXOP (Transmission Opportunity) Limit. CWmin and CWmax represent the minimum and maximum values ​​of the contention window, respectively. The contention window is a parameter used to calculate the transmission waiting time, i.e., backoff, for collision avoidance. AIFS is a fixed transmission waiting time set for each traffic access category. TXOP Limit indicates the upper limit of the channel occupancy period (TXOP). Access category information is represented, for example, by "VO (Voice)," "VI (Video)," "BE (Best Effort)," "BK (Background)," and "LL (Low Latency)."

[0083] Figure 7 This is an example table of information associated with one A-STA in the link management information 132 included in the management unit 130 of the shared AP 10 of the communication system 1 shown in the embodiment. This table sets the information for each A-STA used in a multi-AP connection. Figure 7 As shown, the link management information 132 includes information such as link status, R-TWT function, and TWT protocol group (TWT_AG) link identifier for each link identifier.

[0084] The link management information 132 includes link status information indicating whether the wireless link is active (enabled) or inactive (disabled). In other words, an active link status means that data exchange can be performed using the wirelessly connected A-AP and A-STA. An inactive link status means that data exchange cannot be performed using the wirelessly connected A-AP and A-STA. In this example, link #1 is active, and the other links are set to inactive. In this case, it is assumed that the terminal device 30 is at least within the communicable area of ​​the shared AP 20-1.

[0085] The R-TWT function information included in Link Management Information 132 indicates whether the R-TWT function is enabled or disabled. In this example, the R-TWT function is enabled for links #1, #5, and #9, while the R-TWT function is disabled for other links. In a multi-AP connection, there may also be links like #5 and #9 where the link state is disabled but the R-TWT function is enabled.

[0086] The R-TWT_AG link identifier information included in link management information 132 is the identifier assigned to the link allocated to the multi-AP TWT protocol group. The multi-AP TWT protocol group is set up through the R-TWT protocol setup described later and consists of links with R-TWT functionality enabled. In this example, R-TWT links #1, #2, and #3 are assigned to links #1, #5, and #9, respectively.

[0087] Furthermore, when terminal device 30 moves from the communicable area of ​​shared AP 20-1 to the communicable area of ​​shared AP 20-2 or 20-3, link #1 will become invalid, while link #5 or link #9 may become valid. In this case, since the R-TWT function of links #5 and #9 is valid (enabled), terminal device 30 can quickly begin communication based on the R-TWT procedure (in other words, communication utilizing the R-TWT function) even after the move. That is, in communication system 1, shared AP 10 and terminal device 30 can conduct communication based on the R-TWT procedure when both the detected link status and R-TWT function are valid (enabled).

[0088] Furthermore, the multi-AP management information 131 and link management information 132 can be merged. This information can also be managed using tables in other formats. The management unit 130 can cooperate with the AP-type MLDs of multiple shared APs 20 belonging to the shared AP 10 and the non-AP-type MLDs of the terminal devices 30 to perform the allocation (mapping) of traffic transmitted and received between the shared AP 10 and the terminal devices 30. For example, based on the traffic allocation, the management unit 130 instructs the frame processing unit 140 on the destination of the traffic. Then, the frame processing unit 140 causes the transceiver unit 150 to send traffic to the shared AP 20 based on the instructions from the management unit 130. Specifically, based on the instructions from the management unit 130, traffic allocated to the link associated with the shared AP 20-1 is sent from the transceiver unit 150 of the shared AP 10 to the shared AP 20-1. Furthermore, the management unit 130 can also allocate traffic based on the TID associated with the access class.

[0089] <1-3-2> Functional Structure of Shared AP 20

[0090] Figure 8 This is a block diagram illustrating an example of the functional structure of the shared AP 20 provided in the communication system 1 of the embodiment. For example... Figure 8As shown, the shared AP 20 functions, for example, as a computer equipped with a transceiver unit 210, a management unit 220, a frame processing unit 230, and wireless signal processing units 240-1, 240-2, and 240-3. The management unit 220 and the frame processing unit 230 are functional blocks that perform processing corresponding to the MAC sublayer of Layer 2. The wireless signal processing units 240-1 to 240-3 are functional blocks that perform processing corresponding to both the MAC sublayer of Layer 2 and Layer 1. When the shared AP 10 communicates wirelessly with each shared AP 20, the transceiver unit 210 is a functional block that performs processing corresponding to Layer 1. When the shared AP 10 communicates wiredly with each shared AP 20, the transceiver unit 210 is a functional block that performs processing corresponding to the MAC sublayer of Layer 2.

[0091] The transceiver unit 210 transmits and receives data and management information with the shared access point 10. When the shared access point 20 and the shared access point 10 communicate wirelessly, the transceiver unit 210 includes a wireless signal processing unit. The wireless signal processing unit of the transceiver unit 210 then adds a preamble or the like to the MAC frame input from the frame processing unit 230 to generate a wireless frame. The wireless signal processing unit of the transceiver unit 210 then converts the generated wireless frame into a wireless signal. The wireless signal processing unit then transmits (radiates) the converted wireless signal to the shared access point 10 via an antenna. Additionally, the wireless signal processing unit of the transceiver unit 210 converts the wireless signal received from the shared access point 10 via the antenna into a wireless frame. The wireless signal processing unit extracts the MAC frame from the converted wireless frame and outputs the extracted MAC frame to the frame processing unit 230.

[0092] When the shared AP 20 communicates with the shared AP 10 via a wired connection, the transceiver unit 210 is connected to the shared AP 10 via a wired network. Then, the transceiver unit 210 sends and receives data and management information with the shared AP 10 via the wired network. In this case, the transceiver unit 210 is configured with a network interface of the wired network.

[0093] The management unit 220 controls the establishment of wireless connections (wireless links) between the shared AP 10 and the non-AP type MLD of the terminal device 30 in a multi-AP connection mode. Additionally, the management unit 220 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 mode. During actual data exchange, the management unit 220, based on instructions from the management unit 130 of the shared AP 10, sets each wireless link to be active (enabled) for data exchange or deactivated (disabled). Furthermore, the management unit 220 includes link management information 221 and a beacon generation unit 222.

[0094] Link management information 221 stores management information about the status of the wireless links used in multi-AP connections. Additionally, link management information 221 includes, for example, information about the shared AP 10 to which this station belongs and information about the A-STAs of the terminal devices 30 that have established wireless links with this station. Link management information 221 may store information contained in multi-AP management information 131 and link management information 132. Management unit 220 uses link management information 221 to manage the validity and invalidation of wireless links.

[0095] The beacon generation unit 222 generates a beacon frame containing information about the multi-AP connection and control parameters containing the R-TWT function based on management information received from the shared AP. The beacon generation unit 222 notifies the terminal device 30 of the generated beacon frame via at least one of the frame processing unit 230 and the wireless signal processing units 240-1, 240-2, and 240-3. The beacon frame may contain, for example, information about the shared AP 10, information about the shared AP 20 as the local station, and information about the shared AP 20 as another station included in the multi-AP connection. The beacon frame may also contain multi-AP management information 131 and link management information 132 forwarded from the shared AP 10. The beacon frame can be transmitted via broadcast or multicast.

[0096] Furthermore, the management unit 220 allocates traffic to the wireless link established on the shared AP 20, which serves as the local station, according to the traffic allocation instruction from the shared AP 10. Then, based on the traffic allocation, the management unit 220 notifies the frame processing unit 230 of the destination of the traffic sent to the terminal device 30. Accordingly, the management unit 220 notifies the frame processing unit 230 of information indicating which of the wireless signal processing units 240-1 to 240-3 will output the traffic sent to the terminal device 30.

[0097] When a MAC frame is input from the transceiver unit 210, the frame processing unit 230 outputs the input MAC frame to at least one of the management unit 220 or the wireless signal processing units 240-1 to 240-3, depending on the frame type and traffic allocation. Alternatively, when a MAC frame is input from any of the wireless signal processing units 240-1 to 240-3, the frame processing unit 230 outputs the input frame to either the management unit 220 or the transceiver unit 210, depending on the frame type. For example, when a data frame is input from any of the wireless signal processing units 240-1 to 240-3, the frame processing unit 230 outputs the input frame to the transceiver unit 210. When a data frame is input from the transceiver unit 210, the frame processing unit 230 outputs the input frame to at least one of the wireless signal processing units 240-1 to 240-3. When a management frame or control frame for the local station is input from the transceiver unit 210, the frame processing unit 230 outputs the input frame to the management unit 220. When a management frame or control frame for the terminal device 30 is input from the transceiver unit 210, the frame processing unit 230 outputs the input frame to at least one of the wireless signal processing units 240-1 to 240-3.

[0098] Wireless signal processing units 240-1, 240-2, and 240-3 are each configured to transmit and receive data and management information with the terminal device 30 via wireless communication. Each wireless signal processing unit 240 uses the same frequency band and channel as the wirelessly connected A-STA. Each wireless signal processing unit 240 adds a preamble or the like to the MAC frame input from the frame processing unit 230 to generate a wireless frame. Then, each wireless signal processing unit 240 converts the generated wireless frame into a wireless signal. Subsequently, each wireless signal processing unit 240 transmits (radiates) the converted wireless signal to the terminal device 30 via an antenna. In addition, each wireless signal processing unit 240 converts the wireless signal received from the terminal device 30 via the antenna into a wireless frame. Each wireless signal processing unit 240 extracts the MAC frame from the converted wireless frame and outputs the extracted MAC frame to the frame processing unit 230.

[0099] Furthermore, when the shared AP 10 and the shared AP 20 communicate wirelessly, the transceiver unit 210 and each of the wireless signal processing units 240 can be integrated. In this case, wireless communication between the shared AP 10 and the shared AP 20 can be performed by any of the wireless signal processing units 240-1 to 240-3 or other wireless signal processing units 240 (not shown).

[0100] exist Figure 8In one example shown, when it is a shared AP 20-1, the transceiver unit 210, the management unit 220, and the frame processing unit 230 correspond to AP type MLD#1. When it is a shared AP 20-2, the transceiver unit 210, the management unit 220, and the frame processing unit 230 correspond to AP type MLD#2. When it is a shared AP 20-3, the transceiver unit 210, the management unit 220, and the frame processing unit 230 correspond to AP type MLD#3. Furthermore, when it is a shared AP 20-1, the wireless signal processing units 240-1, 240-2, and 240-3 correspond to A-AP#1, A-AP#2, and A-AP#3, respectively. When it is a shared AP 20-2, the wireless signal processing units 240-1, 240-2, and 240-3 correspond to A-AP#4, A-AP#5, and A-AP#6, respectively. In the case of a shared AP 20-3, the wireless signal processing units 240-1, 240-2 and 240-3 correspond to A-AP#7, A-AP#8 and A-AP#9, respectively.

[0101] <1-3-3> Functional Structure of Terminal Device 30

[0102] Figure 9 This is a block diagram illustrating an example of the functional structure of the terminal device 30 included in the communication system 1 according to an embodiment. The terminal device 30 functions as a computer including 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 wireless signal processing units 350-1, 350-2, and 350-3. The application execution unit 300 is a functional block that performs processing corresponding to Layer 7. The LLC processing unit 310 is a functional block that performs processing corresponding to the LLC sublayer of Layer 2 and Layers 3 to 6. The data processing unit 320, management unit 330, and frame processing unit 340 are functional blocks that perform processing corresponding to the MAC sublayer of Layer 2. The wireless signal processing units 350-1 to 350-3 are functional blocks that perform processing corresponding to the MAC sublayer of Layer 2 and Layer 1.

[0103] The application execution unit 300 executes the application based on data input from the LLC processing unit 310. Additionally, the application execution unit 300 inputs data to the LLC processing unit 310. For example, the application execution unit 300 can display application information on the display 35. Furthermore, the application execution unit 300 can operate based on operations via the input interface.

[0104] LLC processing unit 310 appends DSAP or SSAP headers, etc., to the data input from application execution unit 300 to generate LLC data packets. Then, LLC processing unit 310 inputs the generated LLC data packets to data processing unit 320. Additionally, LLC processing unit 310 extracts data from the LLC data packets input from data processing unit 320. Then, LLC processing unit 310 inputs the extracted data to application execution unit 300.

[0105] The data processing unit 320 appends a MAC header to the LLC data packet input from the LLC processing unit 310 to generate a MAC frame. Then, the data processing unit 320 inputs the generated MAC frame to the frame processing unit 340. Additionally, the data processing unit 320 extracts LLC data packets from the MAC frame input from the frame processing unit 340. Then, the data processing unit 320 inputs the extracted LLC data packets to the LLC processing unit 310.

[0106] The management unit 330 controls the establishment of the wireless connection (wireless link) between the shared AP 10 and the non-AP type MLD of the terminal device 30 in a multi-AP connection mode. The management unit 330 can, for example, obtain management information from beacons received from the shared AP 20. Furthermore, the management unit 330 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 mode. During actual data exchange, the management unit 330, based on the instructions of the management unit 130 of the shared AP 10, sets each wireless link to be active (enabled) for data exchange or deactivated (disabled). Additionally, the management unit 330 includes link management information 331.

[0107] Link management information 331 stores management information about the status of the wireless links used in multi-AP connections. Additionally, link management information 331 includes, for example, information about the shared AP 10 to which this station belongs and information about the A-AP that has established a wireless link with this station's shared AP 20. Link management information 331 may store information contained in multi-AP management information 131 and link management information 132. Management unit 330 uses link management information 331 to manage the validity and invalidation of wireless links.

[0108] 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 wireless signal processing units 240-1 to 240-3 according to the traffic allocation. Conversely, when a MAC frame is input from any of the wireless signal processing units 350-1 to 350-3, the frame processing unit 230 outputs the input frame to either the management unit 330 or the data processing unit 320 according to the frame type. For example, when a data frame is input from any of the wireless signal processing units 350-1 to 350-3, 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 at least one of the wireless signal processing units 350-1 to 350-3. When a management frame or control frame for the local station is input into any of the wireless signal processing units 350-1 to 350-3, the frame processing unit 340 outputs the input frame to the management unit 330.

[0109] Wireless signal processing units 350-1, 350-2, and 350-3 are each configured to transmit and receive data and management information with the shared AP 20 via wireless communication. Each wireless signal processing unit 350 uses the same frequency band and channel as the wirelessly connected AP. Each wireless signal processing unit 350 adds a preamble or the like to the MAC frame input from the frame processing unit 340 to generate a wireless frame. Then, each wireless signal processing unit 350 converts the generated wireless frame into a wireless signal. Then, each wireless signal processing unit 350 transmits (radiates) the converted wireless signal to the shared AP 20 via an antenna. In addition, each wireless signal processing unit 350 converts the wireless signal received from the shared AP 20 via the antenna into a wireless frame. Each wireless signal processing unit 350 extracts the MAC frame from the converted wireless frame and outputs the extracted MAC frame to the frame processing unit 340.

[0110] exist Figure 9 In one example shown, the application execution unit 300, LLC processing unit 310, data processing unit 320, management unit 330, and frame processing unit 340 correspond to non-AP type MLD#1. Additionally, the wireless signal processing units 350-1, 350-2, and 350-3 correspond to A-STA#1, A-STA#2, and A-STA#3, respectively.

[0111] <2> Work

[0112] The operation of the communication system 1 in the next embodiment will be described.

[0113] Figure 10 This is a flowchart illustrating an example of a communication method of a shared AP 10 provided in an embodiment of a communication system. The following refers to... Figure 10An example of the series of processes from establishing a multi-AP connection to setting up the R-TWT function will be described. Furthermore, the operation of the shared AP 10 described below is, for example, performed by the management unit 130.

[0114] For example, a shared AP 10 starts upon a request from a terminal device 30 received via any shared AP 20. Figure 10 A series of processes.

[0115] First, the shared AP 10 establishes a multi-AP connection with the terminal device 30 (S10). In the S10 process, for example, management frames are exchanged between the management unit 130 of the shared AP 10 and the non-AP type MLD of the terminal device 30, and between the management unit 130 of the shared AP 10 and the AP type MLDs of each shared AP 20. In this example, N links #1 to #N are established in the multi-AP connection between the shared AP 10 and the terminal device 30. When the establishment of the multi-link, i.e., the multi-AP connection using multiple shared APs 20, is completed, the shared AP 10 proceeds to the S11 process. Furthermore, in the establishment of the multi-link, authentication and association processing of other links constituting the multi-link can be performed using the initial link established with the terminal device 30, or authentication and association processing can be performed using multiple links.

[0116] In the S11 process, the shared AP 10 selects K links from N links #1 to #N and designates them as multi-AP TWT protocol groups. "N" is an integer of 2 or higher, corresponding to the number of links used in the multi-AP connection. That is, in the S11 process, K links out of the multiple wireless links established under the multi-AP connection are designated as multi-AP TWT protocol groups. Additionally, in the S11 process, the shared AP 10 performs link numbering (1...K). "K" is an integer of 2 or higher, corresponding to the number of links where the R-TWT function is set to be valid. Accordingly, R-TWT links #1 to #K are allocated in the multi-AP connection.

[0117] Next, the shared AP 10 establishes a TWT protocol targeting the multi-AP TWT protocol group (S12). In the S12 process, the TWT protocol is batch-configured for all links included in the multi-AP TWT protocol group. Specifically, in the TWT protocol, an exchange of requests and responses, including identifiers of all the target links, is performed. In the S12 process, the links for which the R-TWT function is set to be valid are determined based on information about the TWT protocol capabilities notified from each shared AP 20. For example, the TWT protocol establishment is implemented via a specific A-AP of the shared AP 20. This specific A-AP, for example, corresponds to a link for which a non-AP type MLD requested TWT protocol establishment. Then, the TWT protocol establishment result is notified to the non-AP type MLD of the terminal device 30. Furthermore, the S12 process can also be referred to as "multi-AP TWT protocol".

[0118] Next, the shared AP 10 sets the start timing of the R-TWT SP (S13). That is, the shared AP 10 determines the TWT start time. In the processing of S13, the TWT period, TWT duration, and suppression transmission period can be set simultaneously. The shared AP 10 can set the TWT start time, TWT duration, and TWT period in conjunction with the low-latency traffic generation period. The shared AP 10 can obtain the low-latency traffic generation period in any way. For example, the shared AP 10 can obtain information such as the data generation period set in the application that generates low-latency traffic from the terminal device 30 for the establishment of the R-TWT function. The set start timing of the R-TWT SP is notified to the AP-type MLD of the shared AP 20 and the non-AP-type MLD of the terminal device 30.

[0119] Next, the process of setting "k=1" is executed (S14). "k" is a variable used to perform the process described later. In the process of S14, the number "1" substituted into k corresponds to the first number of the identifier assigned to the R-TWT link (i.e., the R-TWT protocol group link identifier).

[0120] Next, the shared AP 10 confirms whether R-TWT link #k is valid (enabled) (S15). In the processing of S15, for example, the link status of R-TWT link #k is confirmed by referring to link management information 132.

[0121] In the S15 process, if it is confirmed that the R-TWT link #k is valid (enabled) (S15: Yes), the shared AP 10 proceeds to the S16 process.

[0122] In the S15 process, if it is confirmed that the R-TWT link #k is not valid (enabled) or invalid (disabled) (S15: No), the shared AP 10 proceeds to the S18 process.

[0123] In the S16 process, shared AP 10 checks whether UL (uplink) / DL (downlink) traffic exists on R-TWT link #k. That is, shared AP 10 checks whether there is uplink or downlink traffic allocated to R-TWT link #k.

[0124] In the S16 process, if UL / DL traffic is confirmed to exist in R-TWT link #k (S16: Yes), the shared AP 10 proceeds to the S17 process.

[0125] In the S16 process, if it is confirmed that there is no UL / DL traffic in the R-TWT link #k (S16: No), the shared AP 10 proceeds to the S18 process.

[0126] In the S17 processing, the shared AP 10 schedules the R-TWT SP in R-TWT link #k. That is, during the TWT period, a TWT SP is set with R-TWT link #k as the target.

[0127] In the S18 process, shared AP 10 does not schedule an R-TWT SP on R-TWT link #k. That is, no TWT SP is set for R-TWT link #k during the TWT period. When the S18 process is completed, shared AP 10 proceeds to the S19 process. Alternatively, shared AP 10 can skip the S18 process and proceed to the S19 process.

[0128] In the S19 process, the shared AP 10 confirms whether "k = K" is satisfied. That is, the shared AP 10 confirms whether the S17 or S18 process has been performed on all R-TWT links configured under the multi-AP connection.

[0129] In the process of S19, if it is confirmed that "k = K" is not satisfied (S19: No), the shared AP 10 increments k (S20) and proceeds to the process of S15. Accordingly, the shared AP 10 performs the process of whether to schedule the R-TWT SP for the next R-TWT link.

[0130] In the processing of S19, if it is confirmed that "k = K" is satisfied (S19: Yes), the shared AP 10 ends. Figure 10After a series of processing steps (end), communication system 1 performs communication based on the R-TWT process. In other words, it sends and receives low-latency uplink or downlink traffic in the scheduled R-TWT SP.

[0131] Figure 11 This is a sequence diagram illustrating an example of the process from the establishment of a multi-link communication system 1 in an embodiment to the commencement of R-TWT communication. Figure 11 The diagram shows the processing sequences for shared AP 10, AP-type MLDs #1, #2, and #3 corresponding to shared APs 20-1, 20-2, and 20-3 respectively, A-STAs #1, #2, and #3 corresponding to terminal device 30, and non-AP-type MLD #1. The following refers to... Figure 11 An example of information exchange within the communication system 1 related to the establishment of the R-TWT function will be described. Furthermore, communication between each AP-type MLD and the non-AP-type MLD #1 is performed via valid A-STA and A-AP (not shown) pairs.

[0132] First, a multi-AP connection is established through the processing of S10. Accordingly, a multi-AP connection is established utilizing multiple A-STAs of non-AP type MLD #1 and multiple A-APs of AP type MLDs #1 to #3 belonging to shared AP 10.

[0133] Next, processing related to the establishment of the R-TWT function is performed between the shared AP 10, AP-type MLDs #1 to #3, and the non-AP-type MLD #1. Specifically, firstly, each of the AP-type MLDs #1 to #3 sends information about its TWT protocol capabilities for each link (TWT AC information) to the shared AP 10 (S20). The TWT AC information can be sent based on a request from the shared AP 10, or it can be sent proactively by the AP-type MLDs to the shared AP 10.

[0134] When the shared AP 10 collects the TWT AC information for each link, it notifies each AP-type MLD of information (TWT AC information) regarding whether each link in the established links can utilize the R-TWT function (S21). The information notified to each AP-type MLD in the S21 process includes at least information on all target links (all target links) that can utilize the TWT function.

[0135] Then, each AP-type MLD notifies the non-AP-type MLD#1 via a beacon of the availability of R-TWT information received from the shared AP 10 (S22). Specifically, each A-STA receives the beacon and forwards the availability of R-TWT information contained in the beacon to the non-AP-type MLD#1.

[0136] Based on the information received regarding TWT protocol capabilities, the non-AP type MLD#1 selects (specifies) any number of links among the multiple links established in the multi-AP connection. Then, the non-AP type MLD#1 requests the shared AP 10 to establish the TWT protocol on the selected (specified) links (S23: TWT protocol request).

[0137] Based on the TWT protocol request, the shared AP 10 selects the link to form the TWT protocol and specifies a multi-AP TWT protocol group. Then, the shared AP 10 performs TWT protocol establishment via a specific A-AP of the shared AP 20 and notifies the non-AP type MLD (S24: TWT protocol reply and TWT protocol group notification). This specific A-AP corresponds, for example, to the link where the non-AP type MLD#1 requested TWT protocol establishment. When the processing of S24 is completed, the establishment of the multi-AP TWT protocol is completed (S25). In addition, corresponding to the establishment of the multi-AP TWT protocol, the shared AP 10, each shared AP 20, and the terminal device 30 update their respective link management information as appropriate.

[0138] Subsequently, the shared AP 10 specifies the timing for starting the R-TWT SP and notifies each multi-AP TWT protocol group of this timing. Specifically, it notifies each AP-type MLD of the scheduling information, such as the TWT start time, (S26). Each AP-type MLD sets up the R-TWT function based on the notified scheduling information. Then, each AP-type MLD#1 notifies the notified scheduling information to the non-AP-type MLD#1 (S27). Furthermore, in multi-AP R-TWT SP communication, at the specified timing, R-TWT SPs are scheduled for links with valid UL or DL ​​traffic in the links included in the multi-AP TWT protocol group, and communication based on the R-TWT procedure is executed (S28).

[0139] Figure 12 This is a timing diagram illustrating an example of R-TWT communication in communication system 1 according to an embodiment. Figure 12 The diagram shows the processing sequences for links #1-#3 corresponding to shared AP 20-1, links #4-#6 corresponding to shared AP 20-2, and links #7-#9 corresponding to shared AP 20-3. The following refers to... Figure 12 A summary of communication utilizing the R-TWT function is provided.

[0140] In this example, links #3 and #5 are set to active, while the other links are set to inactive. Then, TWT protocol establishment is performed between shared AP 10 and terminal device 30 using link #3. In this example, the links included in the TWT protocol group are links #3, #5, and #7. The result of the TWT protocol establishment is then applied to links #5 and #7 in the TWT protocol group via shared AP 10. In other words, the result of the TWT protocol establishment is also applied to link #7 of shared AP 20-3 outside the communication area. That is, TWT protocol establishment only requires at least one link in the TWT protocol group to be active. Afterwards, communication utilizing the R-TWT function is implemented in communication system 1.

[0141] When the TWT period begins, each link simultaneously transmits (radiates) beacon signals to notify the R-TWT SP. The beacon signals may contain, for example, management information used in the R-TWT function, such as the TWT start time, TWT duration, TWT interval, and suppression transmission period. Furthermore, this management information used in the R-TWT function is not only contained in the beacon signals but also in the multi-link probe response during multi-link establishment (e.g., ...). Figure 11 The process included in S10 is as follows: When a beacon signal is received, the terminal device 30 acquires the TWT start time, TWT duration, and TWT interval, and notifies each A-STA.

[0142] Accordingly, in links #3 and #5, the R-TWT SP can be set to the same timing. On the other hand, although link #7 is included in the TWT protocol group, the R-TWT SP is omitted because the link is invalid. Frame switching for low-latency traffic is prioritized on links with allocated R-TWT SPs. When the R-TWT SP expires, terminal device 30 and other terminal devices perform frame switching using the valid link until the next TWT cycle.

[0143] Furthermore, in the R-TWT SP, traffic transmission from other terminal devices can be suppressed or prohibited based on the setting of a suppression transmission period. Additionally, depending on the presence or absence of traffic from the shared AP 10 or a Buffer Status Report (BSR) from terminal device 30, the R-TWT SP for this link may not be set, and the suppression transmission period may not be set. This is because, in the absence of traffic, other terminal devices must terminate communication before the R-TWT SP begins, resulting in low communication efficiency.

[0144] <3> Effects of the implementation method

[0145] The communication system 1 according to the embodiments described above can provide a wireless communication environment capable of efficiently transmitting low-latency traffic. Details of the effects of the embodiments will be explained below.

[0146] In a multi-link environment between one AP-type MLD (access point) and one non-AP-type MLD (terminal device), the TWT protocol for all links of that AP-type MLD can be established by executing the TWT protocol through a pair of A-APs and A-STAs. However, the establishment of this TWT protocol does not assume the scenario where multiple shared APs 20 utilize the R-TWT function in a multi-AP connected environment.

[0147] In response to a TWT request from a terminal device 30 connected to the shared AP 10 in the communication system 1 of this embodiment, the shared AP 10 performs TWT protocol establishment for specific or all links of the multiple shared APs 20 belonging to the shared AP 10. At this time, the shared AP 10 summarizes the TWT protocols between any multiple A-APs and A-STAs of the multiple shared APs into a single TWT protocol between one A-AP and A-STA of any shared AP. In other words, the TWT protocol under multiple AP connections is established in a manner that spans links across multiple shared APs. In other words, by using a single link to implement the TWT protocol, the TWT protocol can be established without performing TWT protocol execution for each of the multiple shared APs 20.

[0148] As a result, the communication system 1 of the implementation can implement the TWT protocol based on the valid shared AP 20 link, even for shared AP 20 links that are currently invalid and located outside the communication area. Then, even when the shared AP 20 to which the connection destination is changed, i.e., when a handover is performed, the terminal device 30 can utilize the R-TWT function without reimplementing the TWT protocol.

[0149] Furthermore, the shared AP 10 has established a valid multi-AP TWT protocol group scheduling R-TWT SP with its subordinate A-STAs constituting the multi-AP connection and notifies each shared AP 20. Then, each shared AP 20 sets up its R-TWT SP in response to the notified scheduling information.

[0150] Accordingly, the communication system 1 of this embodiment enables the R-TWT SP to synchronize with the beacon transmission timing of each shared AP 20. As a result, the communication system 1 of this embodiment can implement coordinated communication among multiple shared APs 20 in a multi-AP connection, and can suppress latency and jitter of low-latency traffic. Therefore, the communication system 1 of this embodiment can provide a wireless communication environment that can efficiently transmit low-latency traffic.

[0151] Furthermore, in the communication system 1 of the embodiment, the scheduling of R-TWT SPs can be omitted based on whether there is traffic from the shared AP 10 or a buffer status report (BSR) from the terminal device 30. Accordingly, the communication system 1 of the embodiment can eliminate the communication restrictions on other terminal devices 30 caused by scheduling R-TWT SPs without generating low-latency traffic, and can achieve efficient communication.

[0152] <4> other

[0153] The transformation processes from radio frames to radio signals described in the embodiments include, for example, convolutional coding, interleaving, subcarrier modulation, inverse fast Fourier transform, OFDM modulation, and frequency conversion. The transformation processes from radio signals to radio frames described in the embodiments include, for example, frequency conversion, OFDM demodulation, fast Fourier transform, subcarrier demodulation, deinterleaving, and Viterbi decoding. In a multi-link system, one or more radio links can be assigned to a single traffic type. The association between traffic and radio links is configured, for example, to make the amount of traffic more even across the multiple radio links constituting the multi-link system. Traffic of similar types (preferred / non-preferred, etc.) can be grouped onto specific links constituting the multi-link system.

[0154] In this implementation, the CPU 11 of the shared AP 10, the CPU 21 of the shared AP 20, and the CPU 31 of the terminal device 30 can each be other circuits. For example, the shared AP 10, the shared AP 20, and the terminal device 30 can each have an MPU (microprocessor unit) instead of a CPU. The various processes described in this implementation can also be implemented by dedicated hardware. The processes of the shared AP 10, the shared AP 20, and the terminal device 30 can be a mixture of software-executed processes and hardware-executed processes, or only one of them. The CPU can also be called a "processor". The wireless communication module can also be called a "communication circuit".

[0155] In this implementation, the flowchart used for describing the work is only one example. The processing order of the various operations described in this implementation may be changed to the extent possible, and other processes may be added. For example, the link establishment method and R-TWT communication method described in this implementation are only one example. As the wireless communication standard, a wireless communication standard different from the IEEE 802.11 standard may be used.

[0156] Furthermore, the present invention is not limited to the embodiments described above, and various modifications can be made during implementation without departing from its spirit. Additionally, the embodiments can be combined as appropriate, resulting in combined effects. Moreover, the above embodiments include various inventions, which can be extracted by selecting combinations from a plurality of disclosed constituent elements. For example, if the technical problem can be solved and the desired effect obtained even if several constituent elements are deleted from all the constituent elements shown in the embodiments, the structure with the deleted constituent elements can also be extracted as an invention.

Claims

1. A shared access point in a communication system, the communication system comprising: a shared access point including a first management unit; a shared access point including a second management unit and a first wireless signal processing unit; other shared access points including a third management unit and a second wireless signal processing unit; and a terminal device including a fourth management unit, a third wireless signal processing unit, and a fourth wireless signal processing unit, wherein in the shared access point, The first management unit is configured to: establish a first wireless link between the first wireless signal processing unit and the third wireless signal processing unit, and a second wireless link between the second wireless signal processing unit and the fourth wireless signal processing unit; establish service periods for priority traffic exchange on the first and second wireless links in batches by transmitting and receiving frames between the first and third management units via the first wireless link; and notify the second and third management units of the start time of the service periods respectively.

2. The shared access point according to claim 1, wherein, The first management unit is configured to: schedule the service period for the second wireless link when the second wireless link is active, and not schedule the service period for the second wireless link when the second wireless link is inactive.

3. A shared access point in a communication system, the communication system comprising: a shared access point including a first management unit; a shared access point including a second management unit and a first wireless signal processing unit; other shared access points including second wireless signal processing units; and a terminal device including a third wireless signal processing unit that has established a first wireless link with the first wireless signal processing unit and a fourth wireless signal processing unit that has established a second wireless link with the second wireless signal processing unit, wherein in the shared access point, The second management unit is configured such that, instead of transmitting or receiving frames about setting a service period for which traffic exchange can be preferentially implemented on the first and second wireless links via the first wireless link, it sets the service period for the first wireless link based on information received from the first management unit about the start time of the service period.

4. The shared access point according to claim 3, wherein, The second management unit is configured to: schedule the service period for the first wireless link when the first wireless link is valid, and not schedule the service period for the first wireless link when the first wireless link is invalid, based on the instructions of the first management unit.

5. A terminal device in a communication system, the communication system comprising: a shared access point including a first management unit; a shared access point including a first wireless signal processing unit; and other shared access points including a second wireless signal processing unit; And a terminal device, including: a second management unit; a third wireless signal processing unit that establishes a first wireless link with the first wireless signal processing unit; and a fourth wireless signal processing unit that establishes a second wireless link with the second wireless signal processing unit, wherein in the terminal device, The second management unit is configured to: establish service periods for priority traffic frame switching on the first and second wireless links by sending and receiving frames between the second management unit and the first management unit via the first wireless link; and perform frame switching using the service periods on the first and second wireless links at the same timing.

6. The terminal device according to claim 5, wherein, The second management unit is configured to: after the establishment, receive beacon signals at the same timing on the first wireless link and the second wireless link respectively, and perform frame switching using the service period on the first wireless link and the second wireless link respectively based on the information of the start time of the service period contained in the beacon signal.

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