Access point, transmitting station, and receiving station

Abstract

An access point according to an embodiment is included in an information communication system that is provided with a transmission station, a plurality of access points, and a reception station, and that allocates traffic to the plurality of access points and transfers data from the transmission station to the reception station. The access point includes a reception status management unit and a transmission buffer control unit. The reception status management unit updates reception success / failure information indicating the reception status of the data stored in the transmission buffer on the basis of the start sequence number and the bitmap included in the received reception confirmation frame. The transmission buffer control unit stores data received via the first radio link or the third radio link in a transmission buffer, and determines data transmitted via the first radio link or the second radio link among the data stored in the transmission buffer on the basis of a transmission window. The transmission window is shifted in accordance with the start sequence number included in the reception acknowledgement frame.

Description

Technical Field

[0001] The implementation involves an access point, a transmitting station, and a receiving station. Background Technology

[0002] Wireless LANs (Local Area Networks) are known as information 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 through a wireless LAN. The UHR-SG (ultra-high reliability-study group), which studies next-generation wireless LAN systems standardized by IEEE 802.11, investigated the multi-AP functionality of multiple access points cooperating.

[0003] As one method of multi-AP functionality, multiple second access points connected to the first access point cooperate to perform data communication between the first access point and the terminal device. As a cooperative action among the multiple second access points, for example, consider distributing the traffic of data exchanged between the first access point and a non-AP_MLD (non-access point multi-link device) to the respective second access points for offloading. The non-AP_MLD corresponds to a function block in the terminal device that manages wireless connections utilizing the multi-AP function.

[0004] Furthermore, the 802.11 standard implements receive status sharing using BlockAck between the data sending device (transmitting station) and the data receiving device (receiving station). This allows the transmitting station to confirm data delivery to the receiving station and control the transmit buffer storing data sent to the receiving station. For example, in BlockAck buffer control, acknowledged data can be removed from the transmit buffer, or window control can be implemented for sending subsequent data.

[0005] Existing technical documents

[0006] Non-patent literature

[0007] Non-patent document 1: IEEE Std 802.11TM-2020, “6.3.27 Block Ack”, pp. 436-442, December 2020 Summary of the Invention

[0008] However, when using multi-AP functionality, not all traffic passes through each of the secondary access points. Therefore, each secondary access point cannot acknowledge receipt of data that does not pass through it, and the window of the transmit buffer cannot be properly shifted. Thus, when traffic is distributed to multiple secondary access points via multi-AP functionality, buffer control within the secondary access points becomes a challenge.

[0009] Therefore, the object of the present invention is to provide an access point, transmitting station, and receiving station that can appropriately control the window of the buffer in the overall information communication system when utilizing the multi-AP function.

[0010] An embodiment provides an access point included in an information communication system, the information communication system comprising: a transmitting station; an access point having a first wireless link established with the transmitting station; other access points having a second wireless link established with the transmitting station; and a receiving station having a third wireless link established with the access points and a fourth wireless link established with the other access points, and transmitting data from the transmitting station to the receiving station by distributing traffic to the access points and other access points. The access point includes a reception status management unit and a transmission buffer control unit. The reception status management unit is configured to update reception success or failure information, indicating the reception status of data accumulated in the transmission buffer, based on the start sequence number and bitmap contained in a reception acknowledgment frame received via the first or third wireless link. The transmission buffer control unit is configured to accumulate data received via the first or third wireless link into the transmission buffer, determine the data to be transmitted via the first or second wireless link from the data accumulated in the transmission buffer according to the transmission window, and shift the transmission window according to the start sequence number contained in the reception acknowledgment frame.

[0011] According to the present invention, an access point, a transmitting station, and a receiving station can be provided, which, when utilizing the multi-AP function, can appropriately control the window of the transmitting buffer in the overall information communication system. Attached Figure Description

[0012] Figure 1 This is a block diagram illustrating an example of the overall structure of an information communication system according to an embodiment.

[0013] Figure 2 This is a block diagram illustrating an example of the hardware structure of a shared access point in an information communication system according to an embodiment.

[0014] Figure 3 This is a block diagram illustrating an example of the hardware structure of a shared access point in an information communication system according to an embodiment.

[0015] Figure 4This is a block diagram illustrating an example of the hardware structure of a terminal device included in an information communication system according to an embodiment.

[0016] Figure 5 This is a block diagram illustrating an example of the functional structure of a shared access point in an information communication system according to an embodiment.

[0017] Figure 6 This is a block diagram illustrating an example of the functional structure of a frame processing unit included in a shared access point of an information communication system according to an embodiment.

[0018] Figure 7 This is a block diagram illustrating an example of the functional structure of a shared access point in an information communication system according to an embodiment.

[0019] Figure 8 This is a block diagram illustrating an example of the functional structure of a frame processing unit included in a common access point of an information communication system according to an embodiment.

[0020] Figure 9 This is a block diagram illustrating an example of the functional structure of a terminal device included in an information communication system according to an embodiment.

[0021] Figure 10 This is a block diagram illustrating an example of the functional structure of a frame processing unit included in a terminal device of an information communication system according to an embodiment.

[0022] Figure 11 This is a block diagram illustrating an example of the functional structure of an auxiliary STA included in a terminal device of an information communication system according to an embodiment.

[0023] Figure 12 This is a schematic diagram illustrating an example of the architecture of the MAC sublayer in an information communication system according to an implementation.

[0024] Figure 13 This is a table illustrating an example of the structure of a transmit buffer of a transmitting station in an information communication system according to an embodiment.

[0025] Figure 14 This is a timing diagram illustrating an example of the setup sequence for a multi-AP connection in an information communication system according to an implementation method.

[0026] Figure 15 This is a block diagram illustrating an example of a data transmission method in an information communication system according to an embodiment.

[0027] Figure 16 This is a flowchart illustrating an example of a window control method for a shared access point in an information communication system according to an embodiment.

[0028] Figure 17This is a flowchart illustrating an example of a window control method for a shared access point in an information communication system according to an embodiment.

[0029] Figure 18 This is a schematic diagram illustrating a specific example of a management method for a transmission buffer of a shared access point in an information communication system according to an embodiment.

[0030] Figure 19 This is a flowchart illustrating an example of a window control method for a terminal device included in an information communication system according to an embodiment.

[0031] Figure 20A This is a timing diagram illustrating a specific example of a data transmission sequence in an information communication system according to an embodiment.

[0032] Figure 20B This is a timing diagram illustrating a specific example of a data transmission sequence in an information communication system according to an embodiment. Detailed Implementation

[0033] Hereinafter, an information communication system according to an embodiment will be described with reference to the accompanying drawings. The embodiments illustrate apparatuses and methods for embodying the technical concept of the invention. The drawings are schematic or conceptual diagrams. Hereinafter, constituent elements having substantially the same function and structure will be given the same reference numerals. Numbers following the numerals constituting a reference numeral are referenced by reference numerals including the same numerals and are used to distinguish elements having the same structure from each other. Similarly, numerals following the numbers constituting a reference numeral and "hyphen + number" are each referenced by reference numerals including the same numbers and are used to distinguish elements having the same structure from each other. When it is not necessary to distinguish elements represented by reference numerals including the same numerals or numbers, these elements are referenced by reference numerals including only numerals or numbers. Hereinafter, "access point" will be appropriately omitted and referred to as "AP". In this specification, the first access point in a multi-AP function is referred to as a "sharing access point", and the second access point in a multi-AP function is referred to as a "shared access point".

[0034] <1> structure

[0035] First, the structure of the information communication system 1 according to the embodiment will be described. In the following description, the information communication system 1 will be described under the premise that a multi-AP connection utilizing the multi-AP function has been established.

[0036] <1-1> Overall Structure of Information and Communication System 1

[0037] Figure 1This is a block diagram illustrating an example of the overall structure of the information communication system 1 according to an embodiment. (See diagram for example.) Figure 1 As shown, the information communication system 1 includes a shared AP10, multiple shared AP20s, and a terminal device 30.

[0038] Shared AP10 is a type of access point for a wireless LAN. Shared AP10 connects to the network NW. Shared AP10 is configured to communicate wirelessly with a server (not shown) on the network NW, and can communicate wirelessly with multiple shared APs 20. Shared AP10 establishes a multi-AP connection with the non-AP_MLD of terminal device 30.

[0039] A shared AP20 is a type of access point for a wireless LAN. The shared AP20 is configured to wirelessly communicate with both the shared AP10 and the terminal device 30. Multiple shared AP20s are located far apart from each other and have distinct communication zones. The communication zones of each shared AP20 may overlap with those of other shared AP20s. Figure 1 The image shows two shared APs, 20-1 and 20-2, connected to the shared AP10.

[0040] Terminal device 30 is a wireless terminal such as a smartphone or PC (Personal Computer). Terminal device 30 has multiple affiliated stations (A-STAs) and a non-AP_MLD. The multiple affiliated stations include A-STA1, which is wirelessly connected to shared AP20-1, and A-STA2, which is wirelessly connected to shared AP20-2. The wireless connection between shared AP20 and the affiliated stations is equivalent to the connection between a pair of access points and STAs in the past. Each A-STA can switch its connection destination to another shared AP20 as terminal device 30 moves. The non-AP_MLD is an MLD (multi-link device) that manages the link status and wireless communication of multiple A-STAs. The non-AP_MLD can establish multi-AP connections with shared AP10 and exchange data via multiple affiliated stations and multiple shared AP20s.

[0041] In the information communication system 1, when establishing a multi-AP connection, information about multiple shared APs 20 subordinate to the shared AP 10 and multiple affiliated STAs subordinate to the non-AP_MLD are exchanged between the shared AP 10 and the non-AP_MLD. Thus, the information communication system 1 can centrally perform comprehensive connections between the shared AP 10 and the non-AP_MLD, targeting multiple shared APs 20 and multiple affiliated STAs.

[0042] The wireless communication used in Information and Communication System 1 follows, for example, the IEEE 802.11 standard. The IEEE 802.11 standard provides 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. For example, the 2.4 GHz band, 5 GHz band, 6 GHz band, 45 GHz band, and 60 GHz band can be used as frequency bands in the wireless communication of Information and Communication System 1. Multiple channels can be allocated to each frequency band. Different channels or the same channel can be allocated to A-STA1 and A-STA2. Furthermore, A-STA1 and A-STA2 can utilize either the same frequency band or different frequency bands.

[0043] <1-2> Hardware Structure of Information and Communication System 1

[0044] The hardware structure of the information communication system 1 according to the following embodiment will be described.

[0045] <1-2-1> Hardware Structure of Shared AP10

[0046] Figure 2 This is a block diagram illustrating an example of the hardware structure of a shared AP10 included in an information communication system 1 according to an embodiment. Figure 2 As shown, the shared AP10 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.

[0047] 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 and is used as the operating 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 to transmit and receive data with each shared AP 20. Wired communication module 15 is a circuit used to transmit and receive data via wired signals. Wired communication module 15 is configured to connect to network NW.

[0048] Furthermore, the shared AP10 can also have other hardware configurations. For example, when the shared AP10 is wirelessly connected to the network NW, the wired communication module 15 can be omitted from the shared AP10. When the shared AP10 is wiredly connected to the network NW, the wireless communication module 14 can be omitted from the shared AP10. The antenna can be either built into the shared AP10 or connected externally.

[0049] <1-2-2> Shared AP20 hardware structure

[0050] Figure 3 This is a block diagram illustrating an example of the hardware structure of a shared AP20 included in the information communication system 1 according to an embodiment. Figure 3 As shown, Figure 2 As shown, the common AP20 includes, for example, a CPU21, ROM22, RAM23, and a wireless communication module24.

[0051] 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 that is used as the operating 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 to transmit and receive data with the shared AP 10 and with the terminal device 30.

[0052] In addition, the shared AP20 can also have other hardware structures. For example, the antenna can be built into the shared AP20 or connected externally.

[0053] <1-2-3> Hardware Structure of Terminal Device 30

[0054] Figure 4 This is a block diagram illustrating an example of the hardware structure of the terminal device 30 included in the information communication system 1 according to an embodiment. For example... Figure 4As 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.

[0055] CPU 31 is an integrated circuit capable of executing various programs and controlling the overall operation of terminal device 30. ROM 32 is, for example, a non-volatile semiconductor memory that stores programs, control data, etc., used to control terminal device 30. RAM 33 is, for example, a volatile semiconductor memory used as the operating area of ​​CPU 31. Wireless communication module 34 is configured to transmit and receive wireless signals via an antenna. Wireless communication module 34 is used to transmit and receive data with shared AP 20. Display 35 is, for example, an LCD (Liquid Crystal Display) or an EL (Electro-Luminescence) display. Display 35 displays, for example, a GUI (Graphical User Interface) corresponding to application software. Storage device 36 is a non-volatile storage device, for example, storing system software of terminal device 30.

[0056] Furthermore, the terminal device 30 can also be other hardware structures. For example, if 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 also function as an input interface for the terminal device 30. The antenna can be built into the terminal device 30 or connected externally.

[0057] <1-3> Functional Structure of Information and Communication System 1

[0058] The functional structure of the information communication system 1 according to the embodiment will be described below.

[0059] <1-3-1> Functional Structure of Shared AP10

[0060] Figure 5 This is a block diagram illustrating an example of the functional structure of the shared AP10 provided in the information communication system 1 according to an embodiment. Figure 5 As shown, the shared AP10 functions as a computer, for example, equipped with 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 performs processing corresponding to the LLC sublayer of Layer 2 and Layers 3 through 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. The transmission / reception unit 150 is a functional block that performs processing corresponding to Layer 1.

[0061] LLC processing unit 110, for example, appends DSAP (Destination Service Access Point) headers and SSAP (Destination Service Access Point) headers to data received from network NW, generating LLC data packets. LLC processing unit 110 then inputs the generated LLC data packets to data processing unit 120. Furthermore, LLC processing unit 110 extracts data from the LLC data packets input by data processing unit 120. LLC processing unit 110 then sends the extracted data to network NW.

[0062] 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. The data processing unit 120 then inputs the generated MAC frame to the frame processing unit 140. Furthermore, the data processing unit 120 extracts the LLC data packet from the MAC frame input from the frame processing unit 140. The data processing unit 120 then inputs the extracted LLC data packet to the LLC processing unit 110. The MAC frame including data is also referred to as a "data frame".

[0063] The management unit 130 performs tasks such as establishing a wireless connection (wireless link), mapping data types and links, and setting BlockAck between itself and the non-AP_MLD of the terminal device 30. For example, the management unit 130 performs multi-AP association processing based on a multi-AP association request from the terminal device 30. For example, when the terminal device 30 uses two A-STA1 and A-STA2, through multi-AP association processing, A-STA1 establishes a wireless link with the shared AP 20-1, and A-STA2 establishes a wireless link with the shared AP 20-2.

[0064] Additionally, the management unit 130 manages multi-AP management information 131 and link management information 132. Multi-AP management information 131 includes information related to the access points (i.e., shared AP 10 and shared APs 20-1 and 20-2) and terminal devices 30 used in the multi-AP connection. 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 related to the status of the links established in the multi-AP connection.

[0065] 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 transmit / receive unit 150. Alternatively, when a MAC frame is input from the transmit / receive unit 150, the frame processing unit 140 outputs the input frame to the data processing unit 120 or the management unit 130 according to the frame type. For example, when a data frame is input from the transmit / receive 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 transmit / receive unit 150, the frame processing unit 140 outputs the input frame to the management unit 130. The management frame or control frame may include, 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 controlling the operation of either the shared AP 20 or the terminal device 30, etc.

[0066] The transceiver unit 150 transmits and receives data and management information between itself and each of the multiple shared APs 20 belonging to the shared AP 10. For example, each of the multiple shared APs 20 belonging to the shared AP 10 has one wireless signal processing unit within the transceiver unit 150. Each wireless signal processing unit of the transceiver unit 150 is configured to transmit and receive wireless signals using different frequency bands or channels.

[0067] Each wireless signal processing unit of the transceiver unit 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 (transmits) the converted wireless signal via an antenna to the shared AP 20 with wireless connectivity. Additionally, each wireless signal processing unit of the transceiver unit 150 converts a wireless signal received from any of the shared AP 20 via an antenna into a wireless frame. Each wireless signal processing unit extracts the MAC frame from the converted wireless frame and outputs the extracted MAC frame to the frame processing unit 140. Furthermore, when the transceiver unit 150 simultaneously notifies multiple shared AP 20s, it can also use multicast or broadcast. Multicast and broadcast are used, for example, to transmit beacons.

[0068] In addition, the multi-AP management information 131 may include information related to frequency band, channel, application parameters, and access category. Frequency band information, for example, indicates the frequency band used by the A-STA in the wireless link. Channel information, for example, indicates the channel used by the A-STA in the wireless link. Application parameter information includes, for example, CWmin, CWmax, AIFS (arbitration interframe space), 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 backoff time as a transmission waiting time to avoid collisions. AIFS is a fixed transmission waiting time set for each access category of traffic. TXOPLimit represents 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)."

[0069] Link management information 132 may include information indicating whether the wireless link is enabled or disabled. Multi-AP management information 131 and link management information 132 may also be combined. Frame processing unit 140 may, based on multi-AP management information 131, output data, etc., sent to shared AP 20-1 to the wireless signal processing unit associated with shared AP 20-1, and output data, etc., sent to shared AP 20-2 to the wireless signal processing unit associated with shared AP 20-2. Frame processing unit 140 may also determine the destination of MAC frames input from data processing unit 120 based on the TID (traffic identifier) ​​corresponding to the access category. This process of mapping TID to links is also called "TID-link mapping". In the transmit / receive unit 150, wireless signal processing units may be assigned to transmit and receive data, etc., and wireless signal processing units may also be assigned to transmit management information.

[0070] (Functional structure of the frame processing unit 140 of AP10)

[0071] Figure 6 This is a block diagram illustrating an example of the functional structure of the frame processing unit 140 included in the shared AP10 of the information communication system 1 according to an embodiment. Figure 6As shown, the frame processing unit 140 includes a MAC frame generation unit 141, a transmit buffer control unit 142, a receive status management unit 143, and a reordering buffer unit 144.

[0072] When a bitmap is input from the receive status management unit 143, the MAC frame generation unit 141 generates a BlockAck including the input bitmap and outputs it to the transmit buffer control unit 142. When downlink data or the like is input from the data processing unit 120, the MAC frame generation unit 141 generates a MAC frame by adding headers, etc., and outputs it to the transmit / receive unit 150. The MAC header included in the MAC frame includes a sequence number (SN) assigned for identifying the data.

[0073] The transmit buffer control unit 142 outputs the MAC frame input from the MAC frame generation unit 141 to the transmit / receive unit 150. When the input MAC frame is downlink data, the transmit buffer control unit 142 associates it with the sequence number SN, accumulates it in the transmit buffer, and outputs it to the transmit / receive unit 150. Additionally, the transmit buffer control unit 142 can notify the receive status management unit 143 of the sequence number SN of the data accumulated in the transmit buffer. The handling of data frames in the transmit buffer control unit 142 is the same as the handling of uplink data in non-AP_MLD.

[0074] When the MAC frame input from the transmit / receive unit 150 is a frame from a shared AP 20 connected to the local station, the reception status management unit 143 determines whether it has been correctly received by checking the frame check sequence. The reception status management unit 143 then outputs the correctly received data to the reordering buffer unit 144. Furthermore, based on the sequence number SN information notified from the transmit buffer control unit 142, the reception status management unit 143 generates or updates reception success / failure information for each sequence number SN, managing the success or failure of reception. The reception status management unit 143 updates the reception success / failure information based on the reception success / failure result. Upon receiving a BlockAck request, the reception status management unit 143 generates a bitmap based on the reception success / failure information and outputs it to the MAC frame generation unit 141.

[0075] The reordering buffer unit 144 accumulates MAC frames input from the reception status management unit 143. Furthermore, if the reordering buffer unit 144 has received the sequence numbers (SNs) of the accumulated MAC frames sequentially from the beginning without omission, it outputs the sequentially received MAC frames to the data processing unit 120. For example, the reordering buffer unit 144 can control the reception window of the accumulated MAC frames (data) based on the start sequence number (SSN) of the BlockAck transmitted from the terminal device 30. When sharing uplink traffic on AP 10, the reception window represents the sequence number (SN) of the data transferred from the terminal device 30 and the reception status. In this case, the reordering buffer unit 144 outputs the data containing the sequence number (SN) preceding the start sequence number (SSN) of the BlockAck to the upper layer, and deletes (discards) the data output to the upper layer from the reordering buffer unit 144.

[0076] <1-3-2> Shared AP20 Functional Structure

[0077] Figure 7 This is a block diagram illustrating an example of the functional structure of a shared AP20 provided in the information communication system 1 according to an embodiment. For example... Figure 7 As shown, the shared AP20 functions, for example, as a computer equipped with transmit / receive units 210-1 and 210-2, a management unit 220, frame processing units 230-1 and 230-2, and a data processing unit 240. Transmit / receive units 210-1 and 210-2 are function blocks that perform processing corresponding to Layer 1. Management unit 220 and frame processing units 230-1 and 230-2 are function blocks that perform processing corresponding to the MAC sublayer of Layer 2.

[0078] Transmitter / receiver unit 210-1 transmits and receives data and management information with the shared AP 10 via wireless communication. Transmitter / receiver unit 210-2 transmits and receives data and management information with the terminal device 30 via wireless communication. Transmitter / receiver units 210-1 and 210-2 correspond to frame processing units 230-1 and 230-2, respectively. Each of transmitter / receiver units 210-1 and 210-2 has a wireless signal processing unit. Furthermore, in the shared AP 20, the wireless signal processing units of transmitter / receiver unit 210-1 and transmitter / receiver unit 210-2 are preferably configured to use different frequency bands or channels.

[0079] The wireless signal processing unit of the transceiver unit 210-1 adds preambles and other parameters to the MAC frames (data frames and management frames, etc.) input from the frame processing unit 230-1 to generate wireless frames. Furthermore, the wireless signal processing unit of the transceiver unit 210-1 converts the generated wireless frames into wireless signals and transmits (transmits) the converted wireless signals to the shared AP10 via the antenna. Additionally, the wireless signal processing unit of the transceiver unit 210-1 converts the wireless signals received from the shared AP10 via the antenna into wireless frames. Furthermore, the wireless signal processing unit of the transceiver unit 210-1 extracts the MAC frame from the converted wireless frames and outputs the extracted MAC frame to the frame processing unit 230-1.

[0080] The wireless signal processing unit of the transceiver unit 210-2 adds preambles and other parameters to the MAC frames (data frames and management frames, etc.) input from the frame processing unit 230-2 to generate wireless frames. Furthermore, the wireless signal processing unit of the transceiver unit 210-2 converts the generated wireless frames into wireless signals and transmits (transmits) the converted wireless signals to the terminal device 30 via the antenna. Additionally, the wireless signal processing unit of the transceiver unit 210-2 converts the wireless signals received from the terminal device 30 via the antenna into wireless frames. The wireless signal processing unit of the transceiver unit 210-2 extracts the MAC frame from the converted wireless frames and outputs the extracted MAC frame to the frame processing unit 230-2.

[0081] The management unit 220 controls the establishment of the wireless connection (wireless link) between the shared AP 10 and the non-AP MLD of the terminal device 30 in a multi-AP connection. Additionally, based on notifications from the shared AP 10, the management unit 220 manages the generation and distribution of beacons required for the multi-AP connection, and 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 the multi-AP connection. Furthermore, the management unit 220 includes link management information 221 and a beacon generation unit 222.

[0082] Link management information 221 stores management information related to the status of the wireless link used in a multi-AP connection. Additionally, link management information 221 may include, for example, the identifier of the shared AP 10 to which this station belongs, and the identifier of the A-STA of the terminal device 30 that has established a wireless link with this station. Link management information 221 may also 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.

[0083] The beacon generation unit 222 generates a beacon frame, including information related to the multi-AP connection, based on management information received from the shared AP 10. The beacon generation unit 222 reports the generated beacon frame to the terminal device 30 via the frame processing unit 230-1 and the transmission / reception unit 210-1. The beacon frame may include, for example, information about the shared AP 10, information about the shared AP 20 of the local station, and information about the shared AP 20 of other stations included in the multi-AP connection. The beacon frame may also include 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.

[0084] When a MAC frame is input from the data processing unit 240, the frame processing unit 230-1 outputs the input frame to the transmit / receive unit 210-1. When a MAC frame is input from the transmit / receive 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 transmit / receive 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 addressed to the local station is input from the transmit / receive unit 210-1, the frame processing unit 230-1 outputs the input frame to the management unit 220.

[0085] When a MAC frame is input from the data processing unit 240, the frame processing unit 230-2 outputs the input frame to the transmit / receive unit 210-2. When a MAC frame is input from the transmit / receive 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 transmit / receive 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 addressed to the local station is input from the transmit / receive unit 210-2, the frame processing unit 230-2 outputs the input frame to the management unit 220.

[0086] The data processing unit 240 outputs the MAC frame input from the frame processing unit 230-1 to the frame processing unit 230-2. Conversely, the data processing unit 240 outputs the MAC frame input from the frame processing unit 230-2 to the frame processing unit 230-1.

[0087] (The functional structure of the frame processing units 230-1 and 230-2 of AP20 is shared)

[0088] Figure 8 This is a block diagram illustrating an example of the functional structure of the frame processing units 230-1 and 230-2 included in the shared AP20 of the information communication system 1 according to an embodiment. Figure 8As shown, frame processing unit 230-1 includes a transmit buffer control unit 231-1, a receive status management unit 232-1, and a reordering buffer unit 233-1. Frame processing unit 230-2 includes a transmit buffer control unit 231-2, a receive status management unit 232-2, and a reordering buffer unit 233-2. In each of frame processing units 230-1 and 230-2, the function blocks used change depending on the transmission direction of the frame.

[0089] First, the functional structure of the frame processing units 230-1 and 230-2 used in the case of forwarding traffic from terminal device 30 to shared AP10, that is, when forwarding uplink traffic using shared AP20, will be explained.

[0090] When the MAC frame input from the transmit / receive unit 210-2 is a frame from an A-STA connected to the local station, the reception status management unit 232-2 determines whether it has been correctly received based on the frame check sequence and outputs the correctly received data to the reordering buffer unit 233-2.

[0091] The reordering buffer unit 233-2 stores the MAC frames input from the reception status management unit 232-2. Furthermore, the reordering buffer unit 233 outputs the stored MAC frames to the transmission buffer control unit 231-1 via the data processing unit 240 in the order of their sequence numbers (SN).

[0092] The transmit buffer control unit 231-1 accumulates the MAC frames input from the data processing unit 240 into the transmit buffer, retrieves the MAC frames according to the window control described later, and outputs them to the transmit / receive unit 210-1. Additionally, the transmit buffer control unit 231-1 can generate a BlockAck request and output it to the transmit / receive unit 210-1.

[0093] When the reception status management unit 232-1 receives a BlockAck from the shared AP10, it outputs a bitmap containing the BlockAck to the transmit buffer control unit 231-1. The transmit buffer control unit 231-1 can retrieve the MAC frame that failed to be received using the shared AP10 from the transmit buffer and retransmit it based on the bitmap input from the reception status management unit 232-1.

[0094] Next, the functional structure of the frame processing units 230-1 and 230-2 used in the case of forwarding traffic from the shared AP10 to the terminal device 30, that is, when forwarding downlink traffic using the shared AP20, will be explained.

[0095] When the MAC frame input from the transmit / receive unit 210-1 is a frame from the shared AP10 connected to this station, the reception status management unit 232-1 determines whether it has been received correctly based on the frame check sequence and outputs the correctly received data to the reordering buffer unit 233-1.

[0096] The reordering buffer unit 233-1 stores the MAC frames input from the reception status management unit 232-1. Furthermore, the reordering buffer unit 233-1 outputs the stored MAC frames to the transmission buffer control unit 231-2 via the data processing unit 240 in the order of sequence number SN.

[0097] The transmit buffer control unit 231-2 accumulates the MAC frames input from the data processing unit 240 into the transmit buffer, retrieves the MAC frames according to the window control described later, and outputs them to the transmit / receive unit 210-2. Additionally, the transmit buffer control unit 231-2 can generate a BlockAck request and output it to the transmit / receive unit 210-2.

[0098] When the reception status management unit 232-2 receives a BlockAck from the A-STA of the terminal device 30, it outputs a bitmap containing the BlockAck to the transmit buffer control unit 231-2. The transmit buffer control unit 231-2 can retrieve the MAC frame that failed to be received by the A-STA of the terminal device 30 from the transmit buffer and retransmit it according to the bitmap input from the reception status management unit 232-2.

[0099] <1-3-3> Functional Structure of Terminal Device 30

[0100] Figure 9 This is a block diagram illustrating an example of the functional structure of a terminal device 30 included in the information communication system 1 according to an embodiment. For example... Figure 9 As shown, the terminal device 30 functions as a computer comprising an application execution unit 300, an LLC processing unit 310, a data processing unit 320, a management unit 330, a frame processing unit 340, and A-STA1 and A-STA2. The application execution unit 300 is a function block that performs processing corresponding to Layer 7. The LLC processing unit 310 is a function block that performs processing corresponding to the LLC sublayer of Layer 2 and Layers 3 through 6. The data processing unit 320, management unit 330, and frame processing unit 340 are function blocks that perform processing corresponding to the MAC sublayer of Layer 2. A-STA1 and A-STA2 are function blocks that perform processing corresponding to the MAC sublayer of Layer 2 and Layer 1. For example, the group consisting of the LLC processing unit 310, data processing unit 320, management unit 330, and frame processing unit 340 corresponds to non-AP_MLD.

[0101] The application execution unit 300 executes the application based on the data input from the LLC processing unit 310. Additionally, the application execution unit 300 outputs 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 perform actions based on the operation of the input interface.

[0102] LLC processing unit 310 appends DSAP headers, SSAP headers, etc., to the data input from application execution unit 300 (upper layer) to generate LLC data packets. Then, LLC processing unit 310 outputs 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 outputs the extracted data to application execution unit 300 (upper layer).

[0103] 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. The data processing unit 320 then outputs 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. The data processing unit 320 then outputs the extracted LLC data packets to the LLC processing unit 310.

[0104] The management unit 330 establishes a wireless connection (wireless link) with the shared AP 10, maps data types and links, and sets BlockAck. For example, the management unit 330 can obtain management information from beacons received by 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. Additionally, the management unit 330 includes link management information 331.

[0105] Link management information 331 stores management information related to the status of the wireless link used in a multi-AP connection. Additionally, link management information 331 includes, for example, the identifier of the shared AP 10 to which this station belongs, and information related to the identifier of the shared AP 20 with which this station has established a wireless link. Link management information 331 may also 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.

[0106] When a MAC frame is input from the data processing unit 320, the frame processing unit 340 outputs the input frame to at least one of A-STA1 and A-STA2 according to traffic allocation. Alternatively, when a MAC frame is input from either A-STA1 or A-STA2, the frame processing unit 340 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 either A-STA1 or A-STA2, the frame processing unit 340 outputs the input frame to the data processing unit 320. When a data frame is input from the data processing unit 320, the frame processing unit 340 outputs the input frame to either A-STA1 or A-STA2. When a management frame or control frame for the local station is input from either A-STA1 or A-STA2, the frame processing unit 340 outputs the input frame to the management unit 330.

[0107] A-STA1 and A-STA2 each function as a wireless signal processing unit, configured to transmit and receive data and management information with the shared AP20 via wireless communication. A-STA adds a preamble or similar code to the MAC frame input from the frame processing unit 340 to generate a wireless frame. Then, A-STA converts the generated wireless frame into a wireless signal. Afterward, A-STA transmits the converted wireless signal via an antenna to the wirelessly connected shared AP20. Additionally, A-STA converts the wireless signal received from the wirelessly connected shared AP20 via the antenna into a wireless frame. A-STA extracts the MAC frame from the converted wireless frame and outputs the extracted MAC frame to the frame processing unit 340.

[0108] (Functional structure of frame processing unit 340 of terminal device 30)

[0109] Figure 10 This is a block diagram illustrating an example of the functional structure of the frame processing unit 340 included in the terminal device 30 of the information communication system 1 according to an embodiment. Figure 10 As shown, the frame processing unit 340 includes a transmit buffer control unit 341, a receive status management unit 342, and a reordering buffer unit 343.

[0110] The transmit buffer control unit 341 accumulates data input from the data processing unit 320 in association with the sequence number (SN) in the transmit buffer, extracts MAC frames according to the window control described later, and outputs them to any A-STA. The window is set according to the bitmap of BlockAck (BA) included in the receive status management unit 342. Data dispatch performed by the transmit buffer control unit 341 can also be sent to the A-STA corresponding to the traffic type (TID) according to the TID-link mapping.

[0111] Additionally, the transmit buffer control unit 341 can notify the receive status management unit 342 of the sequence number (SN) of the data accumulated in the transmit buffer. The transmit buffer control unit 341 can generate a BlockAck request (BAR) to trigger a receive acknowledgment and output it to any A-STA. The BlockAck request generated by the transmit buffer control unit 341 includes the start sequence number (SSN). The BlockAck includes the start sequence number (SSN) and a bitmap (information regarding the success or failure of reception for each sequence number (SN) starting with the start sequence number (SSN)).

[0112] When the MAC frame input from the A-STA is a frame from a shared AP20 connected to the local station, the reception status management unit 342 determines whether it has been correctly received based on the frame check sequence. Furthermore, the reception status management unit 342 outputs the correctly received data to the reordering buffer unit 343. Additionally, the reception status management unit 342 generates or updates reception success / failure information based on the sequence number SN notified from the transmit buffer control unit 341. This reception success / failure information manages the reception success / failure result for each sequence number SN. The reception status management unit 342 updates the reception success / failure information based on the reception success / failure result. Upon receiving a BlockAck request, the reception status management unit 342 generates a bitmap based on the reception success / failure information and outputs it to the transmit buffer control unit 341.

[0113] The reordering buffer unit 343 accumulates MAC frames input from the reception status management unit 342. Furthermore, when the reordering buffer unit 343 has received the sequence numbers (SNs) of the accumulated MAC frames sequentially from the beginning without omission, it outputs the sequentially received MAC frames to the data processing unit 320. For example, the reordering buffer unit 343 can control the reception window of the accumulated MAC frames (data) based on the start sequence number (SSN) of the BlockAck, which is transmitted from the shared AP10. When the terminal device 30 receives downlink traffic, the reception window represents the sequence number (SN) of the data transferred from the shared AP10 and the reception status. In this case, the reordering buffer unit 144 outputs the data containing the sequence number (SN) preceding the start sequence number (SSN) of the BlockAck to the upper layer, and deletes (discards) the data output to the upper layer from the reordering buffer unit 343.

[0114] (Functional structure of A-STA in terminal device 30)

[0115] Figure 11 This is a block diagram illustrating an example of the functional structure of an auxiliary STA (A-STA) included in a terminal device 30 of the information communication system 1 according to an embodiment. Figure 11 As shown, A-STA includes a MAC frame generation unit 351, a transmission and reception unit 352, and a MAC frame processing unit 353.

[0116] The MAC frame generation unit 351 generates a MAC frame by adding a MAC header to the data input from the transmit buffer control unit 341, and outputs it to the transmit / receive unit 352. The MAC header includes a sequence number (SN) assigned to identify the data. That is, the sequence number (SN) is output from the non-AP_MLD transmit buffer along with the data.

[0117] The transmitting and receiving unit 352 performs wireless processing on the MAC frames input from the MAC frame generation unit 351 and transmits them. On the other hand, the transmitting and receiving unit 352 extracts MAC frames from the wireless signals received via the antenna and outputs them to the MAC frame processing unit 353.

[0118] The MAC frame processing unit 353 determines whether a MAC frame received from the transmitting / receiving unit 352 has been correctly received based on the frame check sequence. Furthermore, the MAC frame processing unit 353 outputs the correctly received data to the non-AP_MLD frame processing unit 340.

[0119] <2> action

[0120] Next, the operation of the information communication system 1 according to the embodiment will be described.

[0121] <2-1> Architecture of the MAC Sublayer

[0122] Figure 12 This is a schematic diagram illustrating an example of the architecture of the MAC sublayer in an information communication system 1 according to an implementation. Figure 12 The left side shows an example of the architecture of the MAC sublayer in the transmitting side device (transmitting station TX) of the shared AP10 and terminal device 30. Figure 12 The right side shows an example of the MAC sublayer architecture in the shared AP10 and the receiving-side device (receiving station RX) in the terminal device 30. The transmitting station TX corresponds to the terminal device 30, for example, when transmitting uplink traffic, and to the shared AP10, when transmitting downlink traffic. The receiving station RX corresponds to the shared AP10, for example, when transmitting uplink traffic, and to the terminal device 30, when transmitting downlink traffic. Furthermore, Figure 12 The MAC sublayer architecture shown is merely an example. In multi-AP connections, the MAC sublayer can also be divided into a higher-level MAC sublayer that includes processing performed jointly across multiple links, and a lower-level MAC sublayer that includes processing performed for each of the multiple links. (Processing at the sending station TX)

[0123] like Figure 12As shown on the left, after the transmitting station TX completes the LLC layer processing for the transmitted data, it sequentially executes processes S10 to S15 in the MAC layer. The processing described below can be performed by frame processing units 140, 340, etc.

[0124] First, A-MSDU aggregation (S10) is performed. A-MSDU aggregation is the process of combining multiple MSDUs (MAC Service Data Units) input from the LLC layer to create one A-MSDU. An MSDU is a unit of data processed in the LLC layer. When multiple MSDUs have the same receiving station address and the same TID, the sending station TX can use these multiple MSDUs to create an A-MSDU.

[0125] Next, a sequence number SN is assigned to each A-MSDU (S11). The transmitting station TX can manage the sequence number SN for each TID or manage the sequence number SN together across multiple TIDs. The sequence number SN is used to determine the portion of data that the receiving station RX has successfully received.

[0126] Next, for each A-MSDU, fragmentation (S12) is performed. Fragmentation is the process of dividing (splitting) the A-MSDU into pieces. Each fragmented A-MSDU corresponds to an MPDU.

[0127] Next, MPDU encryption (S13) is performed on each MPDU. MPDU encryption is a process of encrypting the MPDU. The encrypted MPDU is configured to be decoded among the shared AP10, shared AP20, and terminal device 30 with established ownership.

[0128] Next, for the encrypted MPDU, a MAC header and error detection code are appended (S14). The MAC header includes the MAC addresses of the sending destination and sending source, Ethernet type field, etc. The error detection code is used to detect errors in the received data at the receiving station RX. For example, CRC (Cyclic Redundancy Check) is used as the error detection code.

[0129] Next, A-MPDU aggregation (S15) is performed. A-MPDU aggregation is a process that combines multiple MPDUs to generate one A-MPDU. The generated A-MPDU is then input into the physical layer.

[0130] In addition, the transmitting station (TX) can perform buffer control using BlockAck. For example, the transmitting station (TX) performs window control to remove acknowledged data from the transmitting buffer or to send subsequent data. Window control includes processes that shift the transmitting window sequentially from the beginning to the acknowledged delivery positions.

[0131] (Processing of the receiving station RX)

[0132] like Figure 12 As shown on the right, after the receiving station RX completes the physical layer processing of the received wireless signal, it sequentially executes processes S20 to S26 in the MAC layer. The processing described below can be performed by frame processing units 140, 340, etc.

[0133] First, A-MPDU depolymerization is performed (S20). A-MPDU depolymerization is the process of depolymerizing (splitting) the A-MPDU input from the physical layer according to MPDU units.

[0134] Next, error detection (S21) is performed. Error detection is the process of using error detection codes (such as CRC) to detect errors in the received data. The error detection in step S21 is performed for each MPDU.

[0135] Next, the reception status is confirmed (S22). Specifically, the reception of the data (MPDU) is determined based on whether error detection was successful. If no error is detected, i.e., the data is successfully received, the receiving station RX performs subsequent processing using the data. On the other hand, if an error is detected, the receiving station RX discards the data containing the error. Furthermore, the receiving station RX updates the reception success / failure information based on the reception result and the data reception status. Additionally, upon receiving a BlockAck request, the receiving station RX transmits a BlockAck request, including a bitmap, to the transmitting station TX using the radio link that received the BlockAck request. This bitmap contains at least a portion of the reception success / failure information.

[0136] Next, MPDU decryption processing (S23) is performed. MPDU decryption processing is the process of decrypting the encrypted MPDU. In a multi-AP connection, when the data is being communicated between devices with a defined home address, the MPDU decryption is successful.

[0137] Next, the MPDU reordering process (S24) is performed. The reordering process is to reorder the successfully received MPDUs according to the sequence number SN.

[0138] Next, fragment reassembly of the reordered MPDU is performed (S25). Fragment reassembly is the process of restoring the A-MSDU by combining multiple MPDUs.

[0139] Next, A-MSDU deaggregation is performed (S26). A-MSDU deaggregation is the process of dividing the recovered A-MSDU into MSDU units. The divided A-MSDUs are then fed into the LLC layer.

[0140] (Structure of the transmit buffer of the transmitting station TX)

[0141] Figure 13 This is a table illustrating an example of the structure of the transmit buffer of the transmitting station TX in the information communication system 1 according to an embodiment. For example... Figure 13 As shown, the transmit buffer stores data for each sequence number SN. In this example, sequence numbers SN#1 to SN#6 are respectively associated with data D1 to D6. Furthermore, the transmit buffer control unit 142 or 341 manages information indicating the reception status of each sequence number SN as reception success or failure information associated with the transmit buffer. Figure 13 The diagram shows the case where data D3 associated with sequence number SN3 is in a state of not being received, while data D associated with other sequence numbers SN is in a state of being successfully received.

[0142] Furthermore, for each of the transmit buffer control units 142 and 341, a transmit window TW is set as the unit for attempting to transmit data. The transmit window TW represents the range of sequence numbers SN to be transmitted. The transmit window TW can be determined, for example, by WindowStart and window size (the number of frames of sequence numbers SN to be transmitted starting from WindowStart). Hereinafter, the last sequence number SN contained in the transmit window TW, which is represented by WindowStart and window size, will also be referred to as "WindowEnd".

[0143] <2-2> How to set up multiple AP connections

[0144] Figure 14 This is a timing diagram illustrating an example of the setup sequence for a multi-AP connection in the information communication system 1 according to an embodiment. Hereinafter, refer to... Figure 14 This is an example illustrating a multi-AP connection setup sequence. Furthermore, in Figure 14 In the diagram, the diagrams of AP20-2 and A-STA2 are omitted.

[0145] First, the shared AP10 notifies each shared AP of multi-AP management information via multicast or broadcast. This multi-AP management information includes, for example, the identifiers of the shared AP10 and shared AP20 used for multi-AP connections. Upon receiving the multi-AP management information, each shared AP20 reports this information using a beacon frame. Each A-STA receives the beacon frame and outputs it to the non-AP_MLD. The non-AP_MLD obtains the multi-AP management information from the input beacon frame. Based on the multi-AP management information, the non-AP_MLD generates a multi-AP association request, including the identifier of the shared AP as the destination and the identifiers of each shared AP, and sends it to the shared AP10 via any A-STA and the shared AP20.

[0146] Based on the multi-AP association request, the shared AP10 sends an association notification (or request) via multicast to its subordinate shared AP20. Furthermore, based on the responses from the shared AP20, which is the object of the multi-AP connection, the shared AP10 sends a multi-AP association response to the non-AP_MLD. Each shared AP20, if it includes itself in the association notification from the shared AP10, returns a response to that notification. The non-AP_MLD, based on the responses from the shared AP10, sends an association notification to each A-STA. Thus, the wireless connection between the associated A-STA and the shared AP20 is established.

[0147] Next, the shared AP10 implements TID-link mapping. Specifically, the shared AP10 sends a TID-link mapping request to the non-AP_MLD. The non-AP_MLD then sends a response to the TID-link mapping request (the TID-link mapping response) back to the shared AP10. Thus, the shared AP10 can associate each TID with a link (corresponding to the shared AP20 in this example) with the non-AP_MLD. In the default settings, for example, each TID is associated with all links. When the shared AP10 wants to associate a specific TID with only a specific link, it uses TID-link mapping to associate that TID with the corresponding link.

[0148] Next, the shared AP10 implements BlockAck settings. Specifically, before exchanging BlockAck, the shared AP10 sends an ADDBA request to the non-AP_MLD. The ADDBA request includes the TID of the object, the buffer size, and the initial value of the start sequence number (SSN). Furthermore, the non-AP_MLD sends its response to the ADDBA request (the ADDBA response) back to the shared AP10. Thus, the shared AP10 can set the implementation parameters for BlockAck during data transfer.

[0149] As described above, in the information communication system 1, the management unit 130 can also cooperate with the non-AP MLDs of multiple shared APs 20 and terminal devices 30 belonging to the shared AP 10 to perform the allocation (mapping) of traffic transmitted and received between the shared AP 10 and the terminal devices 30. Thus, the management unit 130 can instruct the frame processing unit 140 on the destination of the traffic based on the traffic allocation. Furthermore, the frame processing unit 140 can enable the transmission / reception unit 150 to transmit traffic to the shared AP 20 based on the instructions from the management unit 130. For example, 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 transmission / reception unit 150 of the shared AP 10 to the shared AP 20-1.

[0150] <2-3> Data transfer methods

[0151] Figure 15 This is a block diagram illustrating an example of a data transfer method in an information communication system according to an embodiment. Figure 15 The example illustrates a scenario where uplink traffic is transferred from terminal device 30 to shared AP 10 using a multi-AP connection. In this example, A-STA1 is assigned data with odd sequence numbers SN, and A-STA2 is assigned data with even sequence numbers SN. That is, the example illustrates a situation where data with the same TID is mapped to both A-STA1 and A-STA2, and the transmit buffer control unit 341 alternately assigns data to A-STA1 and A-STA2. Furthermore, in a specific example of the data transfer method described below, the case where uplink traffic is assigned sequence numbers SN: #1 to #12 is described.

[0152] In the information communication system 1 of the first embodiment, BlockAck is performed in two phases: (1) end-to-end (between shared AP10 and non-AP_MLD) and (2) per link. (1) non-AP_MLD sends a BlockAck request to shared AP10 to obtain the reception status of all sequence number SNs. (2) each shared AP20 also sends a BlockAck request to shared AP10 to obtain the reception status of all sequence number SNs. (1) and (2) when shared AP10 receives a BlockAck request, it sends back the reception status of all sequence number SNs using BlockAck.

[0153] Furthermore, in the information communication system 1 of the first embodiment, non-AP_MLD shifts the window based on the received status. Specifically, non-AP_MLD shifts the amount of the confirmed received sequence number SN sequentially from the beginning. Additionally, non-AP_MLD deletes (discards) the portion of data that has left the window due to the window shift from the transmission buffer, and sets the data that newly enters the window range due to the window shift as the next transmission target.

[0154] Furthermore, in the information communication system 1 of the first embodiment, each device performs window control of the transmission buffer and reception success / failure information based on the starting sequence number (SSN) of the BlockAck request included on the transmitting side, so that each device independently and decentralizedly controls the transmission buffer and reception success / failure information in a way that matches the transmission buffer and reception success / failure information in the overall system. For example, each shared AP 20, regardless of whether it has data to transmit / buffer, controls the window to stop immediately before the data that cannot be confirmed to have been delivered in the shared AP 10 when observing the overall sequence number SN. Specifically, the shared AP 20 shifts the window to immediately before the starting sequence number (SSN) of the BlockAck received from the shared AP 10.

[0155] <2-3-1> Window control method for shared AP10

[0156] Figure 16 This is a flowchart illustrating an example of a window control method for a shared AP10 provided in an information communication system 1 according to an embodiment. Hereinafter, refer to... Figure 16 This is an example illustrating the window control method for shared AP10.

[0157] In the shared AP10, when uplink data is sent by the terminal device 30, appropriate actions are performed. Figure 16 A series of processes (beginning).

[0158] First, the shared AP10 receives a BlockAck request (BAR) (S30). The source of the BlockAck received by the shared AP10 can be either non-AP_MLD or shared AP20.

[0159] Then, shared AP10 confirms whether the source of the BlockAck request is non-AP_MLD (S31). If the source is confirmed to be non-AP_MLD (S31: "Yes"), shared AP10 proceeds to process S32. If the source is confirmed to be not non-AP_MLD (S31: "No"), shared AP10 proceeds to process S33. Thus, the next processing branch executed by shared AP10 depends on the source of the BlockAck request.

[0160] In the S32 process, the shared AP10 updates its window. Specifically, the WindowStart in the reordering buffer unit 144 is set to the start sequence number SSN within the BlockAck request (Window Start = SSN). That is, in the S32 process, if the source of the BlockAck request for shared AP10 is non-AP_MLD, since the data before the start sequence number SSN has already been acknowledged as received even in the transmitting device (transmitting station), the window for receiving acknowledgments in shared AP10 is shifted. After the S32 process is completed, shared AP10 proceeds to the S33 process.

[0161] In the S33 process, the shared AP10 generates and transmits the BlockAck. Specifically, first, the shared AP10 generates a BlockAck including the SSN and a bitmap. The shared AP10 sets the SSN stored in the BlockAck to the same value as the Window Start in the reordering buffer section 144 (SSN = Window Start). Furthermore, based on the reception success or failure information from the reception status management section 143, the shared AP10 sets the reception status corresponding to each sequence number SN stored in the BlockAck bitmap to 0 (not received) or 1 (received), starting from the start sequence number SSN. Then, the shared AP10 transmits the generated BlockAck to the device (shared AP10 or shared AP20) that requested the BlockAck. After the S33 process is completed, the shared AP10 terminates. Figure 16 A series of processes (end).

[0162] <2-3-2> Window control method for shared AP20

[0163] Figure 17 This is a flowchart illustrating an example of a window control method for a shared AP20 provided in the information communication system 1 according to an embodiment. Hereinafter, refer to... Figure 17 This is an example illustrating the window control method shared by AP20.

[0164] In the shared AP20, when uplink data is transmitted by terminal device 30, appropriate actions are performed. Figure 17 A series of processes (beginning).

[0165] First, the shared AP20 receives the BlockAck (S30). Then, the shared AP20 obtains the start sequence number (SSN) and bitmap from the received BlockAck. Furthermore, the shared AP20 updates the reception success or failure information of the reception status management unit 232 based on the content of the received BlockAck.

[0166] Specifically, the shared AP20 checks whether the start sequence number SSN, represented by BlockAck, is greater than the Window Start set in its own transmit buffer control unit 231 (S41: SSN > Window Start?). If SSN > Window Start (S41: "Yes"), the shared AP20 proceeds to the process in S42. If SSN does not > Window Start (S41: "No"), the shared AP20 proceeds to the process in S42.

[0167] In the S42 process, the shared AP20 update window is used. Specifically, the Window Start in the transmit buffer is set to the start sequence number SSN within BlockAck (Window Start = SSN). That is, in the S42 process, since the data before the start sequence number SSN has already been acknowledged as received even in the transmitting device (transmitting station), the window for receiving acknowledgments in the shared AP20 is moved. After the S42 process is completed, the shared AP20 enters the S42 process.

[0168] In the S43 process, the shared AP20 updates the reception success or failure information. Specifically, based on the 0 (not received) / 1 (received) bitmap contained in BlockAck, the reception status corresponding to each sequence number SN is updated. More specifically, starting from the Window Start of the transmit buffer, the shared AP20 sets the reception status to "1" for sequence number SNs with a "1" set on the bitmap. Furthermore, the shared AP20 maintains the reception status to "0" for sequence number SNs with a "0" set on the bitmap. After the S43 process is completed, the shared AP20 proceeds to the S44 process.

[0169] In the S44 process, the shared AP20 retrieves data from the sequence numbers SN of Window Start to Window End in the transmit buffer that has a receive state of "0" and has data accumulated in the transmit buffer, and sends it to the shared AP10. After the S44 process is completed, the shared AP20 terminates. Figure 17 A series of processes (end).

[0170] Figure 18 This is a schematic diagram illustrating a specific example of a management method for a shared AP20 transmission buffer in an information communication system 1 according to an embodiment. Figure 18 (A) shows the data accumulated in the transmit buffer of the shared AP20-1. Figure 18 (B) shows the data accumulated in the transmit buffer of the shared AP20-2. In this example, Window Start=1 and the window size=6 is set in both shared AP20-1 and AP20-2.

[0171] like Figure 18 As shown, the transmit buffer of AP20-1 accumulates data D1, D3, and D5 corresponding to odd sequence numbers SN#1, #3, and #5 respectively, but does not retain data (null) corresponding to even sequence numbers SN#2, #4, and #6. On the other hand, the transmit buffer of AP20-2 accumulates data D2, D4, and D6 corresponding to even sequence numbers SN#2, #4, and #6 respectively, but does not retain data (null) corresponding to odd sequence numbers SN#1, #3, and #5.

[0172] Furthermore, in each of the shared AP20-1 and AP20-2, a transmission window TW is set according to Window Start=1 and window size=6. Thus, in the information communication system 1 of the embodiment, the transmission buffer of each shared AP20 is controlled in a way that synchronizes the setting of the transmission window TW of each shared AP20-1 and AP20-2 used in the multi-AP connection.

[0173] <2-3-3> Window Control Method of Terminal Device 30

[0174] Figure 19 This is a flowchart illustrating an example of a window control method for a terminal device 30 included in an information communication system 1 according to an embodiment. Hereinafter, refer to... Figure 19 This is an example illustrating the window control method of the terminal device 30.

[0175] When transmitting data in the uplink direction, the terminal device 30 performs appropriate actions. Figure 19 A series of processes (beginning).

[0176] First, the terminal device 30 sends a BlockAck request (S50) to the shared AP10, which is the destination for receiving data, in which the Window Start is stored in the Start Sequence Number SSN.

[0177] Subsequently, terminal device 30 receives BlockAck (S51) using the response to the sent BlockAck request. BlockAck uses the Window Start of the receiving destination as the starting sequence number SSN, including a bitmap that uses it as the starting point (using 0 / 1 to represent the receiving status of each sequence number SN).

[0178] Furthermore, the terminal device 30 updates the reception success or failure information based on the bitmap contained in BlockAck (S52). Specifically, the terminal device 30 sets the reception state to "1" for the sequence number SN that is set to "1" on the bitmap, starting from Window Start. In addition, the terminal device 30 maintains the reception state to "0" for the sequence number SN that is set to "0" on the bitmap.

[0179] Then, the terminal device 30 updates the window (S53). Specifically, the terminal device 30 sets the WindowStart of the transmit buffer to the next sequence number SN after the last sequence number SN that has been successfully received consecutively from the starting sequence number SSN. The reason for this is that data with "1" set on the bitmap starting from the starting sequence number SSN has been acknowledged as received. In addition, the terminal device 30 sets the WindowEnd of the transmit buffer to the value of the starting sequence number SSN plus the window size (Window End = SSN + Window Size). Thus, the terminal device 30 can shift the transmit window TW by an amount that has been consecutively set to "1" starting from the starting sequence number SSN.

[0180] Next, terminal device 30 retrieves data with a receive status of "0" from the sequence numbers SN of Window Start to Window End contained in the transmit buffer and sends it to shared AP10 (S54). That is, terminal device 30 finds new data that can be sent by utilizing the processing window shifting in S53, and then sends it. In the processing of S54, terminal device 30 may also retransmit data that has not been acknowledged (data with a receive status of "0" on the bitmap and accumulated in the transmit buffer).

[0181] <2-4> Specific examples of data transfer sequences

[0182] Figure 20A as well as Figure 20BThis is a timing diagram illustrating a specific example of the data transmission sequence of the information communication system 1 according to an embodiment. Figure 20B Showing the next Figure 20A The timing diagram shown is processed. Furthermore, in... Figure 20A as well as Figure 20B In the non-AP_MLD, the data of the sequence number SN, which is the number within the dashed box, is stored in the respective transmit buffer TB of AP20-1 and AP20-2 and the reordering buffer section 144 of AP10. Additionally, the numbers of the reception status RS recorded under the bitmap of the transmit buffer TB and the reordering buffer section 144 indicate the reception status of adjacent sequence number SNs. Hereinafter, refer to... Figure 20A as well as Figure 20B This section provides a specific example of a data transfer sequence for situations involving forwarding uplink traffic. Furthermore, in the following explanation, the timing of sending the BlockAck request can be arbitrary, but to make the control flow easier to understand, it will be assumed that it is sent in the order of shared AP20-1, shared AP20-2, and non-AP_MLD.

[0183] exist Figure 20A At the start of the process, data with sequence numbers SN#1 to #12 are accumulated in the transmit buffer of terminal device 30 (non-AP_MLD). That is, 12 data items are accumulated in the transmit buffer of non-AP_MLD and assigned sequence numbers #1 to #12 respectively. Then, uplink traffic is sent from non-AP_MLD to shared AP10. Specifically, non-AP_MLD outputs data D1, D3, and D5 with odd sequence numbers SN#1, #3, and #5 to A-STA1, and outputs data D2, D4, and D6 with even sequence numbers SN#2, #4, and #6 to A-STA2. Then, A-STA1 sends data D1, D3, and D5 to shared AP20-1, and A-STA2 sends data D2, D4, and D6 to shared AP20-2.

[0184] The shared AP20-1 accumulates the received data D1, D3, and D5 into the transmit buffer TB to update its own reception success / failure information, and then sends data D1, D3, and D5 to the shared AP10. Then, the shared AP10 updates its own reception success / failure information (reordering buffer section 144) based on whether data D1 was successfully received and whether data D3 and D5 were not received. Afterwards, the shared AP20-1 confirms the reception status after data transmission by sending a BlockAck request to the shared AP10. In this example, the shared AP10 sends a BlockAck (SSN=1, "100000") as a response to the BAR to the shared AP20-1. This "100000" corresponds to a bitmap representing the reception status, starting with the corresponding start sequence number SSN.

[0185] Based on the received BlockAck (SSN=1, "100000"), shared AP20-1 updates its own reception success / failure information and retransmits data D3 and D5 to shared AP10. The retransmitted data is the data with the sequence number SN corresponding to "0" in the received bitmap, and it is the data accumulated in the transmit buffer. Furthermore, in this example, retransmission occurs only once. Shared AP10 updates its own reception success / failure information based on the successful reception of data D3 and the failure to receive data D5. Afterwards, shared AP20-1 confirms the reception status after data transmission by sending a BlockAck request to shared AP10. In this example, shared AP10 sends BlockAck (SSN=1, "101000") as a response to BAR to shared AP20-1. Shared AP20-1 updates its own reception success / failure information based on the received BlockAck (SSN=1, "101000").

[0186] Shared AP20-2 accumulates the received data D2, D4, and D6 into the transmit buffer TB to update its own reception success information, and then sends data D2, D4, and D6 to shared AP10. Shared AP10 then updates its own reception success information based on the successful reception of data D2, D4, and D6. Afterwards, shared AP20-2 sends a BlockAck request to shared AP10, and shared AP10 sends a BlockAck (SSN=1, "111101") as a response to BAR to shared AP20-2. Shared AP20-2 updates its own reception success information based on the received BlockAck (SSN=1, "111101").

[0187] Additionally, after sending data D1~D6, non-AP_MLD confirms the reception status via a BlockAck request. Specifically, non-AP_MLD sends a BlockAck request (SSN=1) to shared AP10. In this example, shared AP10 sends a BlockAck (SSN=1, "111101") as a response to BAR to non-AP_MLD. As a result, the non-AP_MLD's transmit buffer control unit 341, based on the start sequence number SSN=1 and the bitmap, determines that data with sequence numbers SN#1~#4 has been confirmed received, and shifts the Window Start to the next sequence number SN#5, which is the position where reception was successfully achieved consecutively. In this example, the window size is set to 6 frames, so the Window End sequence number is set to SN#10. Furthermore, the transmit buffer control unit 341 discards the confirmed data from the transmit buffer. The start sequence number SSN in the subsequent BlockAck request becomes the shifted window's start sequence number SSN=5.

[0188] Next, non-AP_MLD, based on the sending window TW (SSN=5, Window Size=6) and reception success / failure information, outputs the data D5, D7, and D9 of odd sequence numbers SN#5, #7, and #9 to A-STA1, and the data D2, D4, and D6 of even sequence numbers SN#8 and #10 to A-STA2. Furthermore, A-STA1 sends data D5, D7, and D9 to shared AP20-1, and A-STA2 sends data D8 and D10 to shared AP20-2.

[0189] The shared AP20-1 accumulates the received data D5, D7, and D9 in its transmit buffer and updates its own reception success / failure information. At this point, the transmission of data already sent from the non-AP_MLD to the shared AP20 can be omitted. Then, data D5, D7, and D9 are sent to the shared AP10. Afterwards, the shared AP10 updates its own reception success / failure information based on the successful reception of data D5 and the failure to receive data D7 and D9. Next, the shared AP20-1 sends a BlockAck request to the shared AP10, and the shared AP10 sends a BlockAck (SSN=1, "111111") as a response to the BAR to the shared AP20-1. Based on the received BlockAck (SSN=1, "111111"), the shared AP20-1 updates its own reception success / failure information and retransmits data D7 and D9 to the shared AP10. Furthermore, the shared AP10 updates its own reception success / failure information based on the successful reception of data D7 and the failure to receive data D9. Subsequently, shared AP20-1 sends a BlockAck request to shared AP10. Shared AP10 then sends a BlockAck (SSN=1, "1111111") as a response to BAR to shared AP20-1. Shared AP20-1 updates its own reception success / failure information based on the received BlockAck (SSN=1, "1111111").

[0190] Shared AP20-2 accumulates the received data D8 and D10 into its transmit buffer to update its own reception success information. It then sends data D8 and D10 to shared AP10. Shared AP10, upon successful reception of data D8 and D10, updates its own reception success information. Next, shared AP20-2 sends a BlockAck request to shared AP10, and shared AP10 sends a BlockAck (SSN=1, "1111111101") as a response to the BAR to shared AP20-1. Shared AP20-1, upon receiving the BlockAck (SSN=1, "1111111101"), updates its own reception success information.

[0191] Furthermore, after sending data D5 and D7~D10, non-AP_MLD confirms the reception status via a BlockAck request. Specifically, non-AP_MLD sends a BlockAck request (SSN=5) to shared AP10. Upon receiving the BlockAck request with SSN=5, shared AP10 shifts the start sequence number of the receive window in the reordering buffer unit 144 to SSN=5. Meanwhile, the transmit buffer control unit 142 discards data with SSNs smaller than the updated start sequence number SSN from the reordering buffer unit 144. Additionally, shared AP10 sends a BlockAck (SSN=5, "111101") as a response to BAR to non-AP_MLD. Thus, based on the start sequence number SSN=5 and the bitmap, non-AP_MLD's transmit buffer control unit 341 determines that data with sequence numbers SN#5~#8 has been confirmed received, and shifts the Window Start to the next sequence number SN#9, which is the position where reception was successfully achieved with consecutive numbers. In this example, the window size is set to 6 frames, so the sequence number of the Window End is set to SN#14 (not shown). Furthermore, the transmit buffer control unit 341 discards the acknowledged data from the transmit buffer. The start sequence number SSN in the subsequent BlockAck request becomes the start sequence number SSN=9 of the shifted window.

[0192] Next, non-AP_MLD, based on the transmission window TW (SSN=9, Window Size=6) and reception success / failure information, outputs data D9 and D11 with odd sequence numbers SN#9 and #11 to A-STA1, and data D12 with even sequence number SN#12 to A-STA2. A-STA1 then sends data D9 and D11 to shared AP20-1, and A-STA2 sends data D12 to shared AP20-2.

[0193] Shared AP20-1 accumulates the received data D9 and D11 into its transmit buffer to update its own reception success information. It then sends data D9 and D11 to shared AP10. Afterwards, shared AP10 updates its own reception success information based on the successful reception of data D9 and D11. Next, shared AP20-1 sends a BlockAck request to shared AP10, and shared AP10 sends a BlockAck (SSN=5, "1111111") as a response to BAR to shared AP20-1. Upon receiving the BlockAck (SSN=5, "1111111"), shared AP20-1 shifts its transmit window (TW), updates its own reception success information, and discards data with confirmed reception sequence number SN=5 or earlier from its transmit buffer.

[0194] Shared AP20-2 accumulates the received data D12 in its transmit buffer and updates its own reception success / failure information. It then sends data D12 to shared AP10. Afterwards, shared AP10 updates its own reception success / failure information based on the successful reception of data D12. Next, shared AP20-2 sends a BlockAck request to shared AP10, and shared AP10 sends a BlockAck (SSN=5, "11111111") as a response to the BAR to shared AP20-2. Upon receiving the BlockAck (SSN=5, "11111111"), shared AP20-2 shifts its transmit window (TW), updates its own reception success / failure information, and discards data with confirmed reception sequence number SN=5 and earlier from its transmit buffer.

[0195] After sending data D9, D11, and D12, non-AP_MLD confirms the reception status via a BlockAck request. Specifically, non-AP_MLD sends a BlockAck request (SSN=9) to shared AP10. Upon receiving the BlockAck request with SSN=9, shared AP10 shifts the start sequence number of the receive window in the reordering buffer unit 144 to SSN=9. Furthermore, the transmit buffer control unit 142 discards data with SSNs smaller than the updated start sequence number SSN from the reordering buffer unit 144. Additionally, shared AP10 sends a BlockAck (SSN=9, "1111") as a response to BAR to non-AP_MLD. Thus, non-AP_MLD's transmit buffer control unit 341, based on the start sequence number SSN=9 and the bitmap, determines that data with sequence numbers SN#9~#12 has been confirmed received, and shifts the Window Start to the next sequence number SN following the position of successful reception with consecutive numbers. Furthermore, the transmit buffer control unit 341 discards the data that has been confirmed to be received from the transmit buffer.

[0196] Subsequently, after the shared AP20-1 sends a BlockAck request to the shared AP10, the shared AP10 sends a BlockAck (SSN=9, "1111") to the shared AP20-1 as a response to the BAR. Upon receiving the BlockAck (SSN=9, "1111"), the shared AP20-1 shifts its transmission window (TW), updates its reception success / failure information, and discards data from the transmission buffer up to the sequence number SN=9 that has already been acknowledged.

[0197] Similarly, shared AP20-2 sends a BlockAck request to shared AP10, and shared AP10 sends a BlockAck (SSN=9, "1111") as a response to BAR to shared AP20-2. Upon receiving the BlockAck (SSN=9, "1111"), shared AP20-2 shifts its transmission window (TW), updates its reception success / failure information, and discards data before the confirmed sequence number SN=9 from its transmission buffer.

[0198] As described above, in the data transfer sequence of the information communication system 1 in the embodiment, the settings of the transmission window TW in each transmission buffer are synchronized. Furthermore, the above description illustrates the case of forwarding uplink traffic in a multi-AP connection, i.e., the non-AP_MLD is the transmitting station TX and the shared AP10 is the receiving station RX, but it is not limited to this. Regarding the case of forwarding downlink traffic in a multi-AP connection, i.e., the non-AP_MLD is the receiving station RX and the shared AP is the transmitting station TX, the same operation can be performed by interchangering the operations of the shared AP10 and the non-AP_MLD described above.

[0199] <3> Effects of the implementation method

[0200] Next, the effects of the information communication system 1 according to the implementation method will be explained.

[0201] In the information communication system 1 of the implementation method, each shared AP 20 stores the data it has transmitted in a transmission buffer and manages its reception status. Based on the reception status of all sequence number SNs (i.e., not limited to its own transmitted data) contained in the BlockAck from the shared AP 10 (in the case of uplink traffic) or non-AP_MLD (in the case of downlink traffic), it updates the reception success / failure information and controls the transmission window TW. Furthermore, for each sequence number SN that has been sequentially acknowledged for reception from the beginning, the transmission window TW is shifted, buffer data is discarded, and data corresponding to the newly entered sequence number SN in the transmission window TW is transmitted.

[0202] Thus, in the information communication system 1 of this embodiment, regardless of the transmission / buffering traffic of each device (shared AP10, shared AP20, and terminal device 30), the overall reception status of the sequence number SN is observed and the transmission buffer is controlled. As a result, the control of the transmission buffer of the shared AP20 in the case of multiple AP connections becomes explicit, including the synchronization of window control of the transmission buffers in the end-to-end / system as a whole for each shared AP20.

[0203] As described above, the information communication system 1 of the embodiment can provide a shared AP 20, a transmitting station TX, and a receiving station RX. When utilizing the multi-AP function, the shared AP 20, transmitting station TX, and receiving station RX can appropriately control the window of the transmitting buffer within the overall information communication system 1. Furthermore, by synchronizing window control, the information communication system 1 of the embodiment can reliably forward data end-to-end without the risk of malfunction. Moreover, the information communication system 1 of the embodiment can perform retransmission control at the shared AP 20 level, thus improving data forwarding efficiency.

[0204] <4> other

[0205] The transformation process from wireless frames to wireless signals described in the embodiments includes, for example, convolutional coding, interleaving, subcarrier modulation, inverse fast Fourier transform, OFDM modulation, and frequency conversion. The transformation process from wireless signals to wireless frames described in the embodiments includes, for example, frequency conversion, OFDM demodulation, fast Fourier transform, subcarrier demodulation, deinterleaving, and Viterbi decoding. In this specification, BlockAck may also be referred to as a receive acknowledgment frame. A BlockAck request may also be referred to as a receive acknowledgment request frame.

[0206] In this embodiment, 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 replace the CPU and have an MPU (Micro Processing Unit), etc. The various processes described in this embodiment can also be implemented by dedicated hardware. The processes of the shared AP 10, the shared AP 20, and the terminal device 30 can either include a mixture of software-executed processes and hardware-executed processes, or they can be only one of them. The CPU can also be called a "processor". The wireless communication module can also be called a "communication circuit".

[0207] In this implementation, the flowchart used in the description of the actions is merely an example. The actions described in this implementation may have their processing order interchanged to the extent possible, and additional processes may be added. For example, the link setup method and data forwarding method described in this implementation are merely examples. As a wireless communication standard, a wireless communication standard different from the IEEE 802.11 standard may also be used.

[0208] Furthermore, the present invention is not limited to the embodiments described above, and various modifications can be made during the implementation phase without departing from its essence. Additionally, the embodiments can be appropriately combined, resulting in combined effects. Moreover, the above embodiments include various inventions, and various inventions can be extracted through combinations selected from a plurality of disclosed constituent elements. For example, if the problem can be solved and the effect obtained even if several constituent elements are deleted from all the constituent elements shown in the embodiments, the structure after deleting those constituent elements can be extracted as an invention.

[0209] (Symbol Explanation)

[0210] 1: Information and communication system; 10: Shared access point; 20: Common access point; 30: Terminal device; 11, 21, 31: CPU; 12, 22, 32: ROM; 13, 23, 33: RAM; 14, 24, 34: Wireless communication module; 15: Wired communication module; 35: Display; 36: Storage device; 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, 340: Frame processing unit; 141, 351: MAC frame generation unit; 142, 231, 341: Transmit buffer control unit; 143, 232, 342: Receive status management unit; 144, 233, 343: Reordering buffer unit; 150, 210-1, 210-2, 352: Transmit and receive unit; 222: Beacon generation unit; 300: Application execution unit; 353: MAC frame processing unit; SN: Sequence number; SSN: Start sequence number; TW: Transmit window; TB: Transmit buffer; RS: Receive status.

Claims

1. An access point in an information communication system, the information communication system having: a transmitting station; An access point establishes a first wireless link with the transmitting station; other access points establish a second wireless link with the transmitting station; and a receiving station establishes a third wireless link with the access point and a fourth wireless link with the other access points. The information communication system distributes traffic to the access points and the other access points to forward data from the transmitting station to the receiving station. The access point has the following features: The reception status management unit is configured to update reception success or failure information, which indicates the reception status of data stored in the transmit buffer, based on the start sequence number and bitmap contained in the reception acknowledgment frame received via the first wireless link or the third wireless link. as well as The transmit buffer control unit is configured to accumulate data received via the first wireless link or the third wireless link into the transmit buffer, determine the data to be transmitted via the first wireless link or the second wireless link from the data accumulated in the transmit buffer according to the transmit window, and shift the transmit window according to the start sequence number included in the receive acknowledgment frame.

2. The access point according to claim 1, wherein, The transmit buffer control unit is configured to set the sequence number representing the start of the transmit window to the start sequence number included in the receive acknowledgment frame.

3. The access point according to claim 1, wherein, The transmit buffer control unit is configured to retrieve data from the sequence number contained in the transmit window that has a receive status of not received and has data accumulated in the transmit buffer, and transmit it via the first wireless link or the second wireless link.

4. A transmitting station in an information communication system, the information communication system comprising: a transmitting station; An access point establishes a first wireless link with the transmitting station; other access points establish a second wireless link with the transmitting station; and a receiving station establishes a third wireless link with the access point and a fourth wireless link with the other access points. The information communication system distributes traffic to the access points and the other access points to forward data from the transmitting station to the receiving station. The sending station has: The reception status management unit is configured to update reception success or failure information, which indicates the reception status of data stored in the transmit buffer, based on the start sequence number and bitmap contained in the reception acknowledgment frame received via the first wireless link or the second wireless link. as well as The transmit buffer control unit is configured to accumulate data received from the outside into the transmit buffer, determine the data to be transmitted via the first wireless link or the second wireless link from the data accumulated in the transmit buffer according to the transmit window, and transmit a receive acknowledgment request frame via the first wireless link or the second wireless link. The transmit window is shifted in such a way that the next sequence number after the last sequence number that has been successfully received consecutively from the start sequence number contained in the receive acknowledgment frame becomes the starting point. The receive acknowledgment frame corresponds to the response to the receive acknowledgment request frame.

5. The sending station according to claim 4, wherein, The transmit buffer control unit retrieves data from the sequence number contained in the transmit window that is not received according to the reception success or failure information, and transmits it via the first wireless link or the second wireless link.

6. A receiving station in an information communication system, the information communication system comprising: a transmitting station; access points having a first wireless link established with the transmitting station; other access points having a second wireless link established with the transmitting station; and a receiving station having a third wireless link established with the access points and a fourth wireless link established with the other access points, the information communication system distributing traffic to the access points and the other access points to forward data from the transmitting station to the receiving station, wherein... The receiving station has: The reordering buffer accumulates data correctly received via the third or fourth wireless link and reorders it according to the sequence number; and The reception status management unit is configured to update reception success or failure information indicating the reception status of data based on the sequence number of the data received via the third wireless link or the fourth wireless link. When a reception confirmation request frame is received, the unit sends a reception confirmation frame including a start sequence number and a bitmap based on the reception success or failure information via the third wireless link or the fourth wireless link. If the source of the reception confirmation request frame is the transmitting station, the unit sets the starting point of the reception window of the reordering buffer unit to the start sequence number of the reception confirmation request frame.

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