Access point and centralized control device

Abstract

An access point according to an embodiment of the present invention comprises: a plurality of communication circuits configured to transmit and receive wireless signals; and a processor that uses the plurality of communication circuits to establish a multi-link with each of the plurality of terminal devices, extracts a transmission pattern for a multi-link configuration that achieves the maximum transmission power of each of the plurality of communication circuits and the required throughput of the plurality of terminal devices, within the maximum throughput, and controls the plurality of communication circuits so as to use one of the extracted transmission patterns.

Description

Access Points and Central Control Devices

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

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

[0003] IEEE 802.11be mentions multi-link transmission, in which multiple links (transmission paths) with different frequency channels are established between a terminal device and an access point. In multi-link transmission, multiple affiliated access points (AP_MLDs) equipped in the same housing, called access point multi-link devices (AP_MLDs), and multiple affiliated STAs (STAs) equipped in the same housing, called non-AP_MLDs (non-access point multi-link devices), form pairs and communicate. The AP_MLDs can add and remove devices (links), and can fixedly configure multi-links with as many affiliated APs as possible.

[0004] "Current Status and Directions of IEEE 802.11be, the Future Wi-Fi 7", EVGENY KHOROV et al., IEEE Access Journal, VOLUME 8, May 21, 2020

[0005] However, IEEE 802.11be does not specify a specific process that the AP_MLD must follow when releasing a device. When there are many AP_MLD devices, it becomes necessary to set the transmission power high to accommodate many terminal devices, which results in increased power consumption.

[0006] The present invention has been made in light of the above circumstances, and an object of the present invention is to provide an access point that can save power and ensure communication quality by reducing the transmission power from the AP_MLD.

[0007] The access point of the embodiment comprises a plurality of communication circuits configured to transmit and receive wireless signals, and a processor that establishes a multi-link with each of a plurality of terminal devices using the plurality of communication circuits, extracts a transmission pattern of a multi-link configuration that satisfies the required throughput of the plurality of terminal devices within the maximum transmission power and maximum throughput of each of the plurality of communication circuits, and controls the plurality of communication circuits to use one of the extracted transmission patterns.

[0008] According to the embodiment, it is possible to provide an access point that can save power by reducing the transmission power from the AP_MLD and ensure communication quality.

[0009] FIG. 1 is a block diagram showing an example of the overall configuration of a communication system according to the first embodiment. FIG. 2 is a block diagram showing an example of the hardware configuration of an access point included in the communication system according to the first embodiment. FIG. 3 is a block diagram showing an example of the hardware configuration of a terminal device included in the communication system according to the first embodiment. FIG. 4 is a block diagram showing an example of the functional configuration of an access point included in the communication system according to the first embodiment. FIG. 5 is a block diagram showing an example of the functional configuration of a terminal device included in the communication system according to the first embodiment. FIG. 6 is a flowchart showing an example of link management processing of an access point included in the communication system according to the first embodiment. FIG. 7 is a diagram showing an example of information collection by an access point in the communication system according to the first embodiment. FIG. 8 is a diagram showing an example of A-AP setting by an access point in the communication system according to the first embodiment. FIG. 9 is a schematic diagram showing a first specific example of link processing in the communication system according to the first embodiment. FIG. 10 is a schematic diagram showing a second specific example of link processing in the communication system according to the first embodiment. FIG. 11 is a schematic diagram showing an example of the overall configuration of a communication system according to the second embodiment. FIG. 12 is a block diagram showing an example of the hardware configuration of a centralized control device included in the communication system according to the second embodiment. FIG. 13 is a block diagram showing an example of the functional configuration of a centralized control device 30 included in the communication system according to the second embodiment. FIG. 14 is a flowchart showing an example of a link management process of the centralized control device included in the communication system according to the second embodiment.

[0010] Each embodiment will be described below with reference to the drawings. Each embodiment illustrates an apparatus or method for embodying the technical idea of ​​the invention. The drawings are schematic or conceptual. Hereinafter, the same reference numerals are used to designate components having substantially the same functions and configurations. Letters and "hyphen + number" following a reference numeral are used to distinguish between elements having similar configurations and referenced by the same reference numeral. Hereinafter, "access point" will be abbreviated to "AP" as appropriate. In this specification, a wireless LAN access point may be referred to as a "base station." A terminal device associated with an access point may be referred to as an "associated terminal." "Multilink transmission" may be referred to as "multilink."

[0011] <1> First Embodiment In a communication system 1 according to a first embodiment, an access point can establish a multilink for each of a plurality of terminal devices. The access point is configured to set an A-AP so as to satisfy the required throughput of the plurality of terminal devices associated with the access point. Details of the communication system 1 according to the first embodiment are described below.

[0012] <1-1> Configuration First, a configuration of a communication system 1 according to the first embodiment will be described. In the first embodiment, a case will be described in which a plurality of terminal devices belonging to an access point includes a terminal device that has established a multi-link.

[0013] <1-1-1> Overall configuration of communication system 1 Fig. 1 is a block diagram showing an example of the overall configuration of a communication system 1 according to the first embodiment. As shown in Fig. 1, the communication system 1 includes, for example, an access point 10 and a terminal device 20. In this example, the access point 10 and the terminal device 20 each support multi-link, which uses multiple channels (links), as a communication method.

[0014] The access point 10 is a type of wireless LAN access point. The access point 10 is connected to the network NW by wire or wirelessly and configured to communicate by wire or wirelessly with a server (not shown) on the network NW. The access point 10 is also connected wirelessly to each of the terminal devices 20 and configured to communicate wirelessly with each of the terminal devices.

[0015] The access point 10 includes, for example, an access point multi-link device (AP_MLD) and multiple affiliated APs (A-APs). The AP_MLD is a multi-link device (MLD) that manages the link status and wireless communication of each of the multiple A-APs. The AP_MLD can execute processing for establishing a multi-link between the access point 10 and the terminal devices 20. Each A-AP corresponds to a wireless signal processing unit that can establish a wireless link with at least one of the terminal devices 20. In this example, the access point 10 includes multiple A-APs, A-AP1, A-AP2, A-AP3, and A-AP4.

[0016] Each of the terminal devices 20 is a wireless terminal such as a smartphone or a PC (Personal Computer). Each of the terminal devices 20 is located in an area where it can communicate with the access point 10. Each of the terminal devices 20 is wirelessly connected to the access point 10 and configured to communicate wirelessly with the access point 10.

[0017] The terminal device 20 includes, for example, a non-AP_MLD (non-access point multi-link device) and multiple A-STAs. The non-AP_MLD is an MLD that manages the link status and wireless communication of each of the multiple A-STAs. The non-AP_MLD may also perform processing for establishing a multi-link between the access point 10 and the terminal device 20. In this example, the terminal device 20 includes A-STA1, A-STA2, A-STA3, and A-STA4 as the multiple A-STAs.

[0018] In this example, A-AP1 of the access point 10 establishes a link L1 with A-STA1 of the terminal device 20. A-AP2 of the access point 10 establishes a link L2 with A-STA2 of the terminal device 20. A-AP3 of the access point 10 establishes a link L3 with A-STA3 of the terminal device 20. A-AP4 of the access point 10 establishes a link L4 with A-STA4 of the terminal device 20. In a multi-link connection, different channels are assigned to A-AP1 to A-AP4. Note that the same frequency band may be used for A-AP1 to A-AP4, or different frequency bands may be used. A multi-link may use one or more links. The access point 10 may include two or more A-APs. The terminal device 20 may include two or more A-STAs.

[0019] The wireless communication used in the communication system 1 complies with, for example, the IEEE 802.11 standard. The IEEE 802.11 standard has wireless communication functions based on the OSI (Open Systems Interconnection) reference model. In the OSI reference model, wireless communication functions are divided into seven layers (Layer 1: Physical Layer, Layer 2: Data Link Layer, Layer 3: Network Layer, Layer 4: Transport Layer, Layer 5: Session Layer, Layer 6: Presentation Layer, and Layer 7: Application Layer). The data link layer includes a Logical Link Control (LLC) sublayer and a Media Access Control (MAC) sublayer. Frequency bands used in the wireless communication of the communication system 1 include, for example, the 2.4 GHz band, the 5 GHz band, the 6 GHz band, the 45 GHz band, and the 60 GHz band. Multiple channels are assigned to each frequency band.

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

[0021] 2 is a block diagram showing an example of a hardware configuration of the access point 10 included in the communication system 1 according to the first embodiment. As shown in FIG. 2, the access point 10 includes, for example, a central processing unit (CPU) 11, a read-only memory (ROM) 12, a random access memory (RAM) 13, a wireless communication module 14, and a wired communication module 15.

[0022] The CPU 11 is a processor capable of executing various programs and controls the overall operation of the access point 10. The ROM 12 is, for example, a non-volatile semiconductor memory that stores programs and control data for controlling the access point 10. The RAM 13 is, for example, a volatile semiconductor memory that is used as a work area for the CPU 11. The wireless communication module 14 is a communication circuit configured to be able to send and receive wireless signals via an antenna. The wired communication module 15 is a circuit used to send and receive data, etc., via wired signals and is configured to be connectable to a network NW.

[0023] The access point 10 may have other hardware configurations. For example, the access point 10 may be wirelessly connected to the network NW. In this case, the wired communication module 15 may be omitted from the access point 10. The antenna may be built into the access point 10 or may be externally connected.

[0024] (2: Hardware Configuration of Terminal Device 20) Fig. 3 is a block diagram showing an example of the hardware configuration of the terminal device 20 included in the communication system 1 according to the first embodiment. As shown in Fig. 3, the terminal device 20 includes, for example, a CPU 21, a ROM 22, a RAM 23, a wireless communication module 24, a display 25, and a storage 26.

[0025] The CPU 21 is a processor capable of executing various programs and controls the overall operation of the terminal device 20. The ROM 22 is, for example, a non-volatile semiconductor memory and stores programs and control data for controlling the terminal device 20. The RAM 23 is, for example, a volatile semiconductor memory and is used as a work area for the CPU 21. The wireless communication module 24 is a communication circuit configured to be able to send and receive wireless signals via an antenna. The display 25 displays, for example, a GUI (Graphical User Interface) of application software. The storage 26 is a non-volatile storage device and stores system software and the like for the terminal device 20.

[0026] The terminal device 20 may have other hardware configurations. For example, if the terminal device 20 is an IoT (Internet of Things) terminal or the like, the display 25 may be omitted from the terminal device 20. The antenna may be built into the terminal device 20 or may be externally connected.

[0027] <1-1-3> Functional Configuration of Communication System 1 The functional configuration of the communication system 1 according to the first embodiment will be described below.

[0028] (1: Functional Configuration of Access Point 10) Fig. 4 is a block diagram showing an example of the functional configuration of the access point 10 included in the communication system 1 according to the first embodiment. As shown in Fig. 4, AP_MLD includes a data allocation unit 110 and a management unit 120. A-AP1, A-AP2, A-AP3, and A-AP4 each include a frame processing unit 130 and a transceiver unit 140. The frame processing unit 130 and the transceiver unit 140 of each A-AP are configured in the same way. For this reason, the following description will focus on pairs of frame processing units 130 and transceiver units 140 included in the same A-AP.

[0029] The data allocating unit 110 outputs input data, etc. to a predetermined output destination. For example, the data allocating unit 110 outputs data input from an upper layer to the associated A-AP. The data allocating unit 110 outputs data input from the A-AP to the upper layer. The data allocating unit 110 outputs management information and control information input from the upper layer or the A-AP to the management unit 120. The data allocating unit 110 outputs management information and control information input from the management unit 120 to the upper layer or the associated A-AP.

[0030] The management unit 120 establishes wireless connections (wireless links) with each of the terminal devices 20, maps data types to links, etc. The management unit 120 also manages information such as the link status of the associated terminal devices 20. This information may include the number of associated terminal devices 20, information about their locations, information about user requirements, capabilities, etc. The management unit 120 may also transmit information about the number and locations of associated wireless terminals as publicly known information.

[0031] The frame processing unit 130 is a functional block that executes processing corresponding to the MAC sublayer of the second layer. When data or the like is input from the data allocation unit 110, the frame processing unit 130 adds a MAC header to generate a MAC frame and outputs the MAC frame to the transceiver unit 140. The frame processing unit 130 can generate a beacon signal based on information input from the management unit 120. Furthermore, when a MAC frame is input from the transceiver unit 140, the frame processing unit 130 processes the MAC header and outputs the MAC frame to the data allocation unit 110.

[0032] The transceiver 140 is a functional block that executes processing corresponding to the first layer. The transceiver 140 generates a wireless frame by adding a preamble or the like to the MAC frame input from the frame processing unit 130, and converts the generated wireless frame into a wireless signal. The transceiver 140 then transmits (radiates) the converted wireless signal via an antenna. The transceiver 140 also extracts a MAC frame from the wireless frame received by the antenna and outputs the extracted MAC frame to the frame processing unit 130.

[0033] (2: Functional Configuration of Terminal Device 20) Fig. 5 is a block diagram showing an example of the functional configuration of the terminal device 20 included in the communication system 1 according to the first embodiment. As shown in Fig. 5, non-AP_MLD includes a data allocation unit 210 and a management unit 220. A-STA1, A-STA2, A-STA3, and A-STA4 each include a frame processing unit 230 and a transceiver unit 240. The frame processing unit 230 and transceiver unit 240 of each A-STA are configured in the same way. For this reason, the following description will focus on pairs of frame processing units 230 and transceiver units 240 included in the same A-STA.

[0034] The data allocating unit 210 outputs input data, etc. to a predetermined output destination. For example, the data allocating unit 210 outputs data input from an upper layer to an associated A-STA. The data allocating unit 210 outputs data input from an A-STA to an upper layer. The data allocating unit 210 outputs management information and control information input from an upper layer or an A-STA to the management unit 220. The data allocating unit 210 outputs management information and control information input from the management unit 220 to an upper layer or an associated A-STA.

[0035] The management unit 220 establishes a wireless connection (wireless link) with the access point 10, maps data types to links, and performs other operations. The management unit 220 can also recognize whether the access point AP can use the link management process described below, based on a beacon signal or the like received from the access point 10. The management unit 220 can then select the access point 10 to which the access point 10 belongs, based on information received from the access point 10, such as whether the link management process can be used.

[0036] The frame processing unit 230 is a functional block that executes processing corresponding to the MAC sublayer of the second layer. When data or the like is input from the data allocation unit 210, the frame processing unit 230 adds a MAC header to generate a MAC frame and outputs the MAC frame to the transceiver unit 240. When a MAC frame is input from the transceiver unit 240, the frame processing unit 230 processes the MAC header and outputs the MAC frame to the data allocation unit 210.

[0037] The transceiver 240 is a functional block that executes processing corresponding to the first layer. The transceiver 240 generates a wireless frame by adding a preamble or the like to the MAC frame input from the frame processor 230, and converts the generated wireless frame into a wireless signal. The transceiver 240 then transmits (radiates) the converted wireless signal via an antenna. The transceiver 240 also extracts a MAC frame from the wireless frame received by the antenna and outputs the extracted MAC frame to the frame processor 230.

[0038] <1-2> Operation Next, a description will be given of the operation of the communication system 1 according to the first embodiment. The operation of the access point 10 described below is executed under the control of the management unit 120.

[0039] 6 is a flowchart showing an example of a link management process of the access point 10 included in the communication system 1 according to the first embodiment. When the access point 10 is powered on, it starts the series of processes shown in FIG. 6 (start).

[0040] First, the access point 10 reads pre-settings (step S11). In the processing of step S11, the access point 10 reads, for example, the required throughput of the associated terminal device 20, the maximum throughput of each A-AP (e.g., a maximum of 60 Mbps), and the maximum transmission power of each A-AP (e.g., a maximum of 200 mW). Note that each terminal device 20 may transmit its required throughput to the access point 10 based on an instruction from the access point 10, may transmit it periodically to the access point 10, or may transmit it to the access point 10 when a link is established. The access point 10 stores the required throughput of each terminal device 20 in the ROM 12. Furthermore, the access point 10 reads the required throughput of each terminal device 20, the maximum throughput of each A-AP, and the maximum transmission power of each A-AP, which are stored in the ROM 12.

[0041] Next, the access point 10 determines whether there has been a change in the state of the terminal device 20 to which it belongs (step S12). For example, the access point 10 determines whether there is a new terminal device 20 that has newly connected to the access point 10 or whether there is a terminal device 20 that has disconnected from the access point 10.

[0042] If it is determined that there is no change in the status of the associated terminal device 20 (step S12: NO), the access point 10 repeats the process of step S12. On the other hand, if it is determined that there is a change in the status of the associated terminal device 20 (step S12: YES), the access point 10 collects terminal information from each terminal device 20 (step S13). In the process of step S13, the access point 10 collects terminal information including the number of associated terminal devices 20, the location of each terminal device 20, and the received power of each terminal device 20. Note that each terminal device 20 may transmit the terminal information to the access point 10 based on an instruction from the access point 10, may transmit the terminal information to the access point 10 periodically, or may transmit the terminal information to the access point 10 when a link is established. In addition, a terminal device 20 that has newly connected to the access point 10 includes a required throughput in the terminal information it transmits.

[0043] FIG. 7 is a diagram showing an example of information collection by the access point 10 in the communication system 1 according to the first embodiment. In the example of FIG. 7, the access point 10 in the communication system 1 has established a multilink with two terminal devices 20-1 and 20-2. In the example of FIG. 7, A-AP1 has established a link L1-1 with A-STA1 of the terminal device 20-1 and a link L1-2 with A-STA1 of the terminal device 20-2. A-AP2 has established a link L2-1 with A-STA2 of the terminal device 20-1 and a link L2-2 with A-STA1 of the terminal device 20-2. A-AP3 and A-AP4 have established a link L3-2 with A-STA3 of the terminal device 20-2 and a link L4-2 with A-STA4, respectively. The access point 10 then collects terminal information from the terminal devices 20-1 and 20-2 via these links.

[0044] Next, the access point 10 derives the transmission power required to cover each terminal device 20 (step S14). In the processing of step S14, the access point 10 derives the transmission power capable of covering each of the associated terminal devices 20 based on the terminal information and pre-settings. For example, the access point 10 derives the transmission power required to satisfy the required throughput of the terminal device 20 from the location and received power of the terminal device 20. For example, if the terminal device 20-1 is closer to the access point 10 than the terminal device 20-2 and there is less noise, the access point 10 will set a lower transmission power to the terminal device 20-1 than to the terminal device 20-2.

[0045] Next, the access point 10 derives a pattern that satisfies the required throughput of the terminal device 20 to which it belongs (step S15). In the processing of step S15, the access point 10 derives a transmission pattern that satisfies the required throughput of the terminal device 20 to which it belongs within the maximum transmission power and maximum throughput of each A-AP of the access point 10. For example, the access point 10 derives multiple transmission patterns that satisfy the required throughput of the terminal device 20 to which it belongs. Here, the transmission patterns include a pattern in which links with the terminal device at some A-APs are disconnected, i.e., a pattern in which some A-APs are assigned only to terminal device 20-1. Furthermore, the transmission patterns include a pattern in which all links with some A-APs are disconnected, i.e., a pattern in which some A-APs are not used.

[0046] Next, the access point 10 selects a transmission pattern that can minimize the total transmission power (step S16). In the processing of step S16, the access point 10 selects the transmission pattern with the smallest total transmission power from the transmission patterns derived in the processing of step S15. Furthermore, when it is desired to give priority to a certain terminal device, for example, when it is necessary to transmit at a priority throughput that exceeds the required throughput, the access point 10 may select a transmission pattern that satisfies the priority throughput required by the priority terminal device.

[0047] Next, the access point 10 switches the A-AP and sets the transmission power (step S17). In the process of step S17, the access point 10 switches the A-AP and sets the transmission power in accordance with the A-AP settings of the transmission pattern selected in step S16.

[0048] Then, the process returns to step S12. That is, as long as the power of the access point 10 is on, the operations of steps S12 to S17 are repeated. Note that when the power of the access point 10 is turned off, the series of processes in FIG. 6 ends.

[0049] FIG. 8 is a diagram showing an example of A-AP configuration by an access point 10 in a communication system according to the first embodiment. In the example of FIG. 8, a communication system 1 similar to that of FIG. 7 is used, i.e., the access point 10 establishes multilinks with two terminal devices 20-1 and 20-2. In the example of FIG. 8, A-AP1 and A-AP2 establish links L1-1 and L2-1 with terminal device 20-1's A-STA1 and A-STA2, respectively. Furthermore, A-AP3 and A-AP4 establish links L3-2 and L4-2 with terminal device 20-2's A-STA3 and A-STA4, respectively. For example, in step S17, as shown in FIG. 8, links L1-2 and L2-2 between A-AP1 and A-AP2 and terminal device 20-2's A-STA1 and A-STA2 are released.

[0050] 7, assume that the terminal device 20-1 is closer to the access point 10 than the terminal device 20-2, and that the transmission power from the access point 10 to the terminal device 20-1 can be set lower than that of the terminal device 20-2. In such a case, the transmission pattern is set so that the transmission power of A-AP1 and A-AP2 is lower than the transmission power of A-AP3 and A-AP4, and links L1-1 and L2-1 with the terminal device 20-1 are established, and links L1-2 and L2-2 with the terminal device 20-2 are released. At this time, it is assumed that the throughput required by the terminal devices 20-1 and 20-2 is satisfied.

[0051] By setting it as described above, the transmission power of A-AP1 and A-AP2 is set lower than the transmission power of A-AP3 and A-AP4, making it possible to reduce the total transmission power of the access point 10.

[0052] Below, a first and second specific example of the link management process in the communication system 1 according to the first embodiment will be described in order. In each of the first and second specific examples, the access point 10 establishes a multilink with each of three terminal devices 20-1, 20-2, and 20-3. In this example, the maximum throughput of A-AP1, A-AP2, A-AP3, and A-AP4 is 60 Mbps. The maximum transmission power of A-AP1, A-AP2, A-AP3, and A-AP4 is 200 mW. The terminal devices 20-1 and 20-2 are approximately the same distance away from the access point 10, and the terminal device 20-3 is farther away from the access point 10 than the terminal devices 20-1 and 20-2. Therefore, the transmission power from the access point 10 directed toward the terminal device 20-3 is greater than that directed toward the terminal devices 20-1 and 20-2. For example, in the first and second specific examples, the transmission power required from the access point 10 to the terminal devices 20-1 and 20-2 is 100 mW, and the transmission power required from the access point 10 to the terminal device 20-3 is 200 mW. In the first specific example, the required throughput for the terminal devices 20-1, 20-2, and 20-3 is 30 Mbps. In the second specific example, the required throughput for the terminal devices 20-1, 20-2, and 20-3 is 60 Mbps.

[0053] (First Specific Example) Fig. 9 is a schematic diagram showing a first specific example of link processing in the communication system according to the first embodiment. Fig. 9 shows an example in which the access point 10 derives multiple transmission patterns in the processing of step S15. Figs. 9(a) and 9(b) show transmission patterns 1 and 2, respectively, derived by the access point 10. In the example of Fig. 9, the access point 10 can satisfy the required throughput of the terminal device 20 to which it belongs with only two A-APs.

[0054] In the example of FIG. 9(a), A-AP1 has established a link L1-1 with A-STA1 of terminal device 20-1, a link L1-2 with A-STA1 of terminal device 20-2, and a link L1-3 with A-STA1 of terminal device 20-3. A-AP2 has established a link L2-1 with A-STA2 of terminal device 20-1, a link L2-2 with A-STA2 of terminal device 20-2, and a link L2-3 with A-STA2 of terminal device 20-3. Furthermore, A-AP1 and A-AP2 each transmit at a power of 200 mW and a throughput of 60 Mbps. Therefore, the total transmission power of the access point 10 is 400 mW. Furthermore, S-STA1 and S-STA2 of each terminal device 20 receive at a throughput of 20 Mbps, for a total of 40 Mbps. Therefore, the required throughput of each terminal device 20 is satisfied.

[0055] In the example of FIG. 9(b), A-AP1 has established a link L1-1 with A-STA1 of terminal device 20-1, and a link L1-2 with A-STA1 of terminal device 20-2. A-AP2 has established a link L2-3 with A-STA2 of terminal device 20-3. Furthermore, A-AP1 and A-AP2 each transmit with a transmission power of 100 mW and a throughput of 60 Mbps. Therefore, the total transmission power of the access point 10 is 300 mW. Furthermore, S-STA1 of terminal device 20-1 and terminal device 20-2 receives with a throughput of 30 Mbps, and S-STA2 of terminal device 20-3 receives with a throughput of 60 Mbps. Therefore, the required throughput of each terminal device 20 is met.

[0056] In the above example, the total transmission power of the transmission pattern in Fig. 9(b) is lower than the total transmission power of Fig. 9(a), so the access point 10 sets the A-AP to have the transmission pattern in Fig. 9(b).

[0057] (Second Specific Example) Fig. 10 is a schematic diagram showing a second specific example of link processing in the communication system according to the first embodiment. Fig. 10 shows an example in which the access point 10 derives multiple transmission patterns in the processing of step S15. Figs. 9(a) and 9(b) show transmission patterns 1 and 2, respectively, derived by the access point 10. In the example of Fig. 9, the access point 10 can satisfy the required throughput of the terminal device 20 associated with four A-APs.

[0058] In the example of FIG. 10(a), A-AP1 has established a link L1-3 with A-STA1 of terminal device 20-3. A-AP2 has established a link L2-1 with A-STA2 of terminal device 20-1 and a link L2-2 with A-STA2 of terminal device 20-2. A-AP3 has established a link L3-1 with A-STA3 of terminal device 20-1 and a link L3-2 with A-STA3 of terminal device 20-2. A-AP4 has established a link L4-1 with A-STA4 of terminal device 20-1 and a link L4-2 with A-STA4 of terminal device 20-2. Furthermore, A-AP1 transmits with a transmission power of 200 mW and a throughput of 60 Mbps. A-AP2, A-AP2, and A-AP3 each transmit with a transmission power of 100 mW and a throughput of 60 Mbps. Therefore, the total transmission power of the access point 10 is 500 mW. Furthermore, S-STA2, S-STA3, and S-STA4 of the terminal devices 20-1 and 20-2 each receive with a throughput of 30 Mbps, for a total of 90 Mbps for the three. Furthermore, S-STA1 of the terminal device 20-3 receives with a throughput of 60 Mbps. Therefore, the required throughput of each terminal device 20 is met.

[0059] In the example of FIG. 10(b), A-AP1 and A-AP2 have established links L1-3 and L2-3 with A-STA1 and S-STA2 of terminal device 20-3, respectively. A-AP3 has established links L3-1 and L3-2 with A-STA3 of terminal devices 20-1 and 20-2. A-AP4 has established links L4-1 and L4-2 with A-STA4 of terminal devices 20-1 and 20-2. Furthermore, A-AP1 and A-AP2 transmit with a transmission power of 200 mW and a throughput of 60 Mbps. A-AP3 and A-AP4 each transmit with a transmission power of 100 mW and a throughput of 60 Mbps. Therefore, the total transmission power of the access point 10 is 600 mW. Furthermore, S-STA3 and S-STA4 of terminal devices 20-1 and 20-2 each receive at a throughput of 30 Mbps, for a total of 60 Mbps. Furthermore, S-STA1 and S-STA2 of terminal device 20-3 receive at a throughput of 60 Mbps, for a total of 120 Mbps. Therefore, the required throughput of each terminal device 20 is met.

[0060] In the above example, the total transmission power of the transmission pattern in Fig. 10(a) is lower than the total transmission power of Fig. 10(b), so the access point 10 sets the A-AP to have the transmission pattern in Fig. 10(a).

[0061] As shown in Figures 9 and 10, a link is established using the same A-AP for terminal devices 20 at a similar distance (within a range of the transmission power required by the access point 10). For example, the access point 10 can reduce transmission power by using multi-user transmission using a communication method such as OFDMA for the terminal device 20. In other words, the transmission pattern adopted by the access point 10 is a transmission pattern in which the transmission power to the terminal device 20 is transmitted by multi-user transmission to terminal devices within a certain range. Therefore, there is no need to match the transmission power required by a terminal device 20 that is further away.

[0062] For example, if priority needs to be given to the terminal device 20-3 and the priority throughput of the terminal device 20-3 is 120 Mbps, the access point 10 may set the A-AP to have the transmission pattern shown in FIG. 10(b). <1-3> Effects of the First Embodiment As described above, in the communication system 1 according to the first embodiment, the access point 10 sets the A-AP so as to reduce the total transmission power of the access point 10 while satisfying the required throughput of the terminal device 20 to which it belongs. For example, the access point 10 assigns the same A-AP to a terminal device 20 that requires the same level of transmission power as the access point 10. This allows the access point 10 to satisfy the required throughput of the terminal device 20 to which it belongs and reduce the total transmission power.

[0063] <2> Second embodiment <2-1-1> Overall configuration of communication system 1 In the communication system 1 according to the second embodiment, the A-AP settings of the access point 10 are performed by a centralized control device to which multiple access points are connected. Details of the second embodiment will be described below, focusing on the differences from the first embodiment.

[0064] 11 is a schematic diagram showing an example of the overall configuration of a communication system 1A according to the second embodiment. The communication system 1A includes, for example, access points 10-1 and 10-2 and a central control device 30.

[0065] Each of the access points 10-1 and 10-2 has a configuration similar to that of the access point 10 described in the first embodiment. Each of the access points 10-1 and 10-2 is configured to be able to execute the link management process described in the first embodiment. Each of the access points 10-1 and 10-2 is configured to transmit information INFO to the centralized control device 30. The information INFO may include information collected by the access point 10 from the terminal device 20 described in the first embodiment, information stored in the ROM of the access point 10, etc. The information INFO may include the status of each A-AP within the access point 10, the configuration of the AP_MLD, the status of the terminal device 20 to which it belongs, etc.

[0066] The central control device 30 is connected to two or more access points 10 and is configured to transmit instructions to switch the A-AP settings of the access points based on information collected by the access points.

[0067] Here, the centralized control device 30 and the access points 10 may be configured such that the centralized control device 30 serves as a sharing access point and the access points 10 serve as shared access points 10. The number of access points 10 and the number of terminal devices 20 included in the communication system 1A may be any other number.

[0068] <2-1-2> Hardware Configuration of Centralized Control Device 30 Fig. 12 is a block diagram showing an example of the hardware configuration of the centralized control device 30 included in the communication system 1A according to the second embodiment. As shown in Fig. 12, the centralized control device 30 includes, for example, a central processing unit (CPU) 31, a read-only memory (ROM) 32, a random access memory (RAM) 33, a wireless communication module 34, a display 35, and a wired communication module 36.

[0069] The CPU 31 is a processor capable of executing various programs and controls the overall operation of the centralized control device 30. The ROM 32 is, for example, a non-volatile semiconductor memory and stores programs and control data for controlling the centralized control device 30. The RAM 33 is, for example, a volatile semiconductor memory and is used as a work area for the CPU 31. The wireless communication module 34 is a communication circuit configured to be able to send and receive wireless signals via an antenna. The display 35 displays, for example, a GUI (Graphical User Interface) of application software. The wired communication module 36 is a circuit used to send and receive data, etc. via wired signals and is configured to be connectable to a network NW.

[0070] The centralized control device 30 may have other hardware configurations. For example, the centralized control device 30 may be wirelessly connected to the network NW. In this case, the wired communication module 36 may be omitted from the centralized control device 30. The antenna may be built into the centralized control device 30 or may be externally connected.

[0071] Furthermore, the functional configuration of the centralized control device 30 may be the same as that of a general server, or may be the same as that of the access point 10 included in the communication system 1 according to the first embodiment. Other configurations of the communication system 1A according to the second embodiment are the same as those of the communication system 1 according to the first embodiment.

[0072] <2-1-3> Functional configuration of the centralized control device 30 Fig. 13 is a block diagram showing an example of the functional configuration of the control device 40 included in the communication system 1A according to the second embodiment. As shown in Fig. 13, the centralized control device 30 includes, for example, a transmitting / receiving unit 310, a frame processing unit 320, and a link management unit 330.

[0073] The transmitting / receiving unit 310 is configured to be able to transmit and receive data, control instructions, etc. to and from the access point 10 via the network NW. The transmitting / receiving unit 310 transmits data, etc. input from the frame processing unit 320 to the access point 10 via the network NW. The transmitting / receiving unit 310 also extracts frames from signals received via the network NW and inputs them to the frame processing unit 320.

[0074] The frame processing unit 320 extracts data and the like from the frame input from the transmitting / receiving unit 310 and inputs the extracted data to the link management unit 330. The frame processing unit 320 also inputs control instructions and the like input from the link management unit 330 to the transmitting / receiving unit 310.

[0075] The link management unit 330 inputs and outputs data etc. between the frame processing unit 320 and manages the state of the link between the access point 10 and the associated terminal device 20. The link management unit 330 can generate, for example, a setting instruction instructing the access point 10 to switch A-AP and change transmission power.

[0076] <2-2> Operation The operation of the communication system 1A according to the second embodiment will be described below. The operation of the central control device 30 described below is executed based on the control of the link management unit 330.

[0077] Fig. 14 is a flowchart showing an example of a link management process of the centralized control device 30 included in the communication system 1A according to the second embodiment. When the centralized control device 30 is powered on, it starts the series of processes shown in Fig. 14 (start).

[0078] First, the centralized control device 30 reads the pre-settings (step S21). In the processing of step S21, the centralized control device 30 reads the required throughput (e.g., 30 Mbps) of the terminal device 20 belonging to each access point 10, the maximum throughput of each A-AP (e.g., maximum 60 Mbps), the maximum transmission power of each A-AP (e.g., 200 mW), etc. Note that each terminal device 20 may transmit its required throughput to the access point 10 based on an instruction from the access point 10, may periodically transmit it to the access point 10, or may transmit it to the access point 10 when a link is established, and the access point 10 may then transmit it to the centralized control device 30. The centralized control device 30 stores the required throughput of each terminal device 20 in the ROM 32. Furthermore, the centralized control device 30 reads the required throughput of each terminal device 20, the maximum throughput of each A-AP, and the maximum transmission power of each A-AP stored in the ROM 32.

[0079] Alternatively, the pre-setting information may be input, i.e., manually set, by an administrator of the centralized control device 30. For example, the administrator may input the required throughput of each terminal device 20.

[0080] Next, the central control device 30 determines whether to receive collected information (step S22). As described in steps S12 and S13 of the first embodiment, when a new terminal device 20 has newly connected to the access point 10 or a terminal device 20 has disconnected from the access point 10, the access point 10 collects terminal information from each terminal device 20. Then, the access point 10 transmits the collected information to the central control device 30.

[0081] Next, the centralized control device 30 derives the transmission power required to cover each terminal device 20 (step S23). The operation of step S23 may be the same as the operation of step S14 in the first embodiment. For example, the centralized control device 30 derives the transmission power required to cover each terminal device 20 belonging to the access point 10 based on the terminal information and the pre-settings. For example, the centralized control device 30 derives the transmission power required to satisfy the required throughput of the terminal device 20 based on the position and received power of the terminal device 20.

[0082] Next, the centralized control device 30 derives a transmission pattern that satisfies the required throughput of the terminal devices 20 that belong to the access point 10 (step S24). The operation of step S24 may be the same as the operation of step S15 in the first embodiment. For example, the centralized control device 30 derives a transmission pattern that satisfies the required throughput of the terminal devices 20 that belong to the access point 10 within the maximum transmission power and maximum throughput of each A-AP of the access point 10. For example, the access point 10 derives multiple transmission patterns that satisfy the required throughput of the terminal devices 20 that belong to it.

[0083] Next, the centralized control device 30 selects a transmission pattern that can minimize the total transmission power (step S25). The operation of step S25 may be the same as the operation of step S16 in the first embodiment. For example, the centralized control device 30 selects the transmission pattern with the smallest total transmission power from among the transmission patterns derived in the processing of step S24.

[0084] Alternatively, the transmission pattern may be selected manually by an administrator of the centralized control device 30. For example, the centralized control device 30 outputs the transmission pattern derived in step S24 to the display 350. The administrator may select an arbitrary transmission pattern from the transmission patterns displayed on the display.

[0085] Next, the access point 10 transmits an instruction to switch the A-AP and set the transmission power (step S26). The operation of step S26 may be the same as the operation of step S17 in the first embodiment. For example, the centralized control device 30 transmits a setting instruction to the access point 10 to switch the A-AP and set the transmission power in accordance with the A-AP setting of the transmission pattern selected in step S25. The access point 10 sets the A-AP in accordance with the setting instruction.

[0086] Then, the process returns to step S22. That is, as long as the power of the centralized control device 30 is on, the operations of steps S22 to S26 are repeated. Note that when the power of the centralized control device 30 is turned off, the series of processes in FIG. 13 ends.

[0087] <2-3> Effects of the Second Embodiment As described above, in the communication system 1A according to the second embodiment, the centralized control device 30 sets an A-AP so as to reduce the total transmission power of the access point 10 while satisfying the required throughput of the terminal devices 20 associated with the access point 10. For example, the centralized control device 30 assigns the same A-AP to terminal devices 20 that require the same level of transmission power as the access point 10. This allows the access point 10 to satisfy the required throughput of the associated terminal devices 20 while reducing the total transmission power.

[0088] <3> Others The conversion process from radio frames to radio signals described in the above embodiments includes, for example, convolutional coding, interleaving, subcarrier modulation, inverse fast Fourier transform, OFDM modulation, and frequency conversion. The conversion process from radio signals to radio frames described in the above embodiments includes, for example, frequency conversion, OFDM demodulation, fast Fourier transform, subcarrier demodulation, deinterleaving, and Viterbi decoding. A wireless communication standard other than the IEEE 802.11 standard may be used as the wireless communication standard.

[0089] In the above-described embodiments, the CPU 11 of the access point 10, the CPU 21 of the terminal device 20, and the CPU 31 of the centralized control device 30 may each be other circuits. For example, the access point 10, the terminal device 20, and the centralized control device 30 may each include an MPU (Micro Processing Unit) or the like instead of a CPU. Each of the processes described in each embodiment may be realized by dedicated hardware. The processes of the access point 10, the terminal device 20, and the centralized control device 30 may be a mixture of processes executed by software and processes executed by hardware, or may be only one of them.

[0090] The present invention is not limited to the above-described embodiments, and various modifications can be made in the implementation stage without departing from the spirit of the invention. Furthermore, the embodiments may be implemented in appropriate combinations, in which case the combined effects can be obtained. Furthermore, the above-described embodiments include various inventions, and various inventions can be extracted by combining selected elements from the disclosed elements. For example, if the problem can be solved and the desired effect can be obtained even if some elements are deleted from all elements shown in the embodiments, the configuration from which these elements are deleted can be extracted as an invention.

[0091] DESCRIPTION OF SYMBOLS 1, 1A...Communication system 10, 10-1, 10-2...Access point 20, 20-1, 20-2, 20-3, 20-4...Terminal device 11, 21, 31...CPU 12, 22, 32...ROM 13, 23, 33...RAM 14, 24, 34...Wireless communication module 15, 36...Wired communication module 25, 35...Display 26...Storage 110, 210...Data distribution unit 120, 220...Management unit 130, 230, 420...Frame processing unit 140, 240, 410...Transmission / reception unit 330...Link management unit

Claims

1. An access point comprising: a plurality of communication circuits configured to transmit and receive wireless signals; and a processor that establishes a multi-link with each of a plurality of terminal devices using the plurality of communication circuits, extracts a transmission pattern of a multi-link configuration that satisfies the required throughput of the plurality of terminal devices within the maximum transmission power and maximum throughput of each of the plurality of communication circuits, and controls the plurality of communication circuits to use one of the extracted transmission patterns.

2. The access point according to claim 1, wherein the extracted transmission pattern is a transmission pattern that minimizes the total transmission power of the plurality of communication circuits.

3. The access point according to claim 1, wherein the extracted transmission pattern is a transmission pattern that satisfies a priority throughput required by a priority terminal device among the plurality of terminal devices.

4. The access point of claim 1, wherein when the processor determines that a new terminal device has connected, the processor collects location information, received power, and required throughput from the plurality of terminal devices and derives the transmission power required to cover each of the plurality of terminal devices.

5. The access point according to claim 1, wherein the transmission pattern includes a transmission pattern in which transmission power to the plurality of terminal devices is transmitted to terminal devices within a certain range in a multi-user transmission.

6. The access point according to claim 1, wherein the transmission patterns include a transmission pattern in which at least one of the plurality of terminal devices has disconnected a link with the plurality of terminal devices.

7. A centralized control device comprising: an access point communication circuit configured to connect to an access point that has established a multi-link with each of a plurality of terminal devices using a plurality of communication circuits; and a processor that extracts a transmission pattern of a multi-link configuration that satisfies the required throughput of the plurality of terminal devices within the maximum transmission power and maximum throughput of each of the plurality of communication circuits, and transmits an instruction through the access point communication circuit to control the plurality of communication circuits to use one of the extracted transmission patterns.

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