Base station and terminal

Abstract

The base station (10) of the embodiment includes first and second wireless signal processing sections (130, 140) and a link management section (120). The first and second wireless signal processing sections are configured to be able to transmit and receive wireless signals using first and second channels, respectively. The link management section creates a multi-link with a terminal using the first and second wireless signal processing sections, and sets a primary link that is mainly used and a secondary link that is secondarily used for the multi-link. The link management section transmits a first wireless frame that requests a change of the primary link to the terminal using the first wireless signal processing section set as the primary link, and causes the primary link to change from the first wireless signal processing section to the second wireless signal processing section if either of the first and second wireless signal processing sections receives an affirmative response from the terminal after the first wireless frame is transmitted.

Description

[0001] This application is a divisional application of Chinese National Application No. 2020801046010 (PCT / JP2020 / 028670) (Base Station and Terminal) filed on July 27, 2020, the contents of which are quoted below. Technical Field

[0002] The implementation methods involve base stations and terminals. Background Technology

[0003] Wireless LAN (Local Area Network) is a known wireless system that connects base stations and terminals wirelessly.

[0004] Non-patent literature 1: IEEE Std 802.11-2016, “Figure 4-25 Establishing the IEEE 802.11 association” and “11.3 STA authentication and association”, 7 December 2016 Summary of the Invention

[0005] The problem with this invention is to improve communication stability in multi-link scenarios.

[0006] The base station in this embodiment includes a first wireless signal processing unit, a second wireless signal processing unit, and a link management unit. The first wireless signal processing unit is configured to transmit and receive wireless signals using a first channel. The second wireless signal processing unit is configured to transmit and receive wireless signals using a second channel different from the first channel. The link management unit uses the first and second wireless signal processing units to create multiple links with the terminal, and sets a primary link for main use and secondary links for auxiliary use in the multiple links. The link management unit uses the first wireless signal processing unit, which is set as the primary link, to send a first wireless frame to the terminal requesting a change of the primary link. If either the first or second wireless signal processing unit receives a positive response from the terminal after sending the first wireless frame, the primary link is changed from the first wireless signal processing unit to the second wireless signal processing unit.

[0007] The effects of the invention

[0008] The base station implemented in this way can improve communication stability in multi-link scenarios. Attached Figure Description

[0009] Figure 1 This is a conceptual diagram illustrating an example of the overall structure of the wireless system according to the first embodiment.

[0010] Figure 2This is a conceptual diagram illustrating a specific example of the format of a wireless frame in the wireless system according to the first embodiment.

[0011] Figure 3 This is a block diagram illustrating an example of the structure of a base station in the wireless system according to the first embodiment.

[0012] Figure 4 This is a block diagram illustrating an example of the base station functionality of the wireless system according to the first embodiment.

[0013] Figure 5 This is a block diagram illustrating an example of the structure of a terminal in the wireless system according to the first embodiment.

[0014] Figure 6 This is a block diagram illustrating an example of the terminal functionality of the wireless system according to the first embodiment.

[0015] Figure 7 This is a block diagram illustrating an example of the detailed functions of the link management unit of a base station in the wireless system according to the first embodiment.

[0016] Figure 8 This is a flowchart illustrating an example of multi-link processing in the wireless system according to the first embodiment.

[0017] Figure 9 This is a table representing an example of link management information of the wireless system according to the first embodiment.

[0018] Figure 10 This is a flowchart illustrating an example of a data transmission method in a multi-link wireless system according to the first embodiment.

[0019] Figure 11 This is a flowchart illustrating an example of the execution conditions for the primary change processing of the wireless system according to the first embodiment.

[0020] Figure 12 This is a flowchart illustrating a specific example of the initial change processing of the wireless system according to the first embodiment.

[0021] Figure 13 It means based on Figure 12 The table below illustrates an example of changes to the link management information during the initial change processing.

[0022] Figure 14 This is a conceptual diagram illustrating a specific example of a wireless frame used in the primary change processing of the wireless system according to the first embodiment.

[0023] Figure 15This is a conceptual diagram illustrating a specific example of a wireless frame used in the primary change processing of the wireless system according to the first embodiment.

[0024] Figure 16 This is a flowchart illustrating a specific example of a multi-link power-saving method for a wireless system according to the second embodiment.

[0025] Figure 17 It means based on Figure 16 The table below illustrates an example of changes in link management information for multi-link power saving usage examples.

[0026] Figure 18 This is a flowchart illustrating a specific example of the initial change processing of the wireless system according to the second embodiment.

[0027] Figure 19 It means based on Figure 18 The table below illustrates an example of changes to the link management information during the initial change processing.

[0028] Figure 20 This is a conceptual diagram illustrating an example of the frequency band used in wireless communication in the wireless system according to the third embodiment.

[0029] Figure 21 This is a flowchart illustrating an example of the execution conditions for channel change processing in the wireless system according to the third embodiment.

[0030] Figure 22 This is a flowchart illustrating a specific example of channel change processing in the wireless system according to the third embodiment.

[0031] Figure 23 It means based on Figure 22 The table below illustrates an example of changes in link management information during channel change processing.

[0032] Figure 24 This is a conceptual diagram illustrating a specific example of a wireless frame used in the channel change processing of the wireless system according to the third embodiment.

[0033] Figure 25 This is a flowchart illustrating a specific example of channel change processing in a wireless system according to the first variation of the third embodiment.

[0034] Figure 26 This is a flowchart illustrating a specific example of channel change processing in a wireless system according to the second variation of the third embodiment. Detailed Implementation

[0035] The embodiments will now be described with reference to the accompanying drawings. Examples of embodiments illustrate apparatuses and methods for realizing the technical ideas of each invention. The drawings are schematic or conceptual. The dimensions and proportions of the drawings may not be identical to reality. The technical ideas of the present invention are not determined by the shape, structure, or arrangement of structural elements. Furthermore, in the following description, structural elements having substantially the same function and structure are labeled with the same reference numerals.

[0036] <1> First Embodiment

[0037] The wireless system 1 according to the first embodiment relates to a method for switching a primary link set in a multi-link system. The wireless system 1 according to the first embodiment will now be described.

[0038] <1> Structure of Wireless System 1

[0039] <1-1-1> Regarding the overall structure of wireless system 1

[0040] Figure 1 This illustrates an example of the structure of the wireless system 1 according to the first embodiment. For example... Figure 1 As shown, the wireless system 1 includes, for example, a base station 10, a terminal 20, and a server 30.

[0041] Base station 10 is connected to network NW and used as an access point for a wireless LAN. For example, base station 10 can wirelessly distribute data received from network NW to terminal 20. Furthermore, base station 10 can utilize one or more bandwidths to connect to terminal 20. In this specification, the wireless connection utilizing multiple bandwidths between base station 10 and terminal 20 is referred to as "multi-link". Communication between base station 10 and terminal 20 is based, for example, on the IEEE 802.11 standard.

[0042] Terminal 20 can be a wireless terminal such as a smartphone or tablet PC. Terminal 20 can send and receive data with server 30 on network NW via base station 10, which is connected wirelessly. Alternatively, terminal 20 can be other electronic devices such as desktop computers or laptops. Terminal 20 is only required to be an instrument that can at least communicate with base station 10 and perform the actions described later.

[0043] Server 30 can store various types of information, such as content data for terminal 20. Server 30 is configured to connect to network NW via a wired connection, and can communicate with base station 10 via network NW. Furthermore, server 30 only needs to be able to communicate with base station 10 at least. That is, communication between base station 10 and server 30 can be wired or wireless.

[0044] In the wireless system 1 according to the first embodiment, the data communication between the base station 10 and the terminal 20 is based on the OSI (Open Systems Interconnection) reference model. In the OSI reference model, the communication function is divided into 7 layers (Layer 1: Physical Layer, Layer 2: Data Link Layer, Layer 3: Network Layer, Layer 4: Transport Layer, Layer 5: Session Layer, Layer 6: Display Layer, Layer 7: Application Layer).

[0045] The data link layer includes, for example, the LLC (Logical Link Control) layer and the MAC (Media Access Control) layer. The LLC layer, for example, appends DSAP (Destination Service Access Point) headers and SSAP (Source Service Access Point) headers to data input from the upper-level application to form LLC data packets. The MAC layer, for example, appends MAC headers to LLC data packets to form MAC frames.

[0046] Figure 2 This section shows a specific example of the format of the wireless frames used in communication between the base station 10 and the terminal 20 in the wireless system 1 according to the first embodiment. For example... Figure 2 As shown, a wireless frame may include, for example, the Frame Control field, Duration field, Address1 field, Address2 field, Address3 field, Sequence Control field, other control information fields, Frame Body field, and FCS (Frame Check Sequence) field.

[0047] The Frame Control field corresponds to other control information fields, such as the MAC header contained in the MAC frame. The Frame Body field corresponds to, for example, the MAC payload contained in the MAC frame. The FCS field stores error detection symbols in the MAC header and Frame Body fields, used to determine the presence or absence of errors in the radio frame.

[0048] The Frame Control field represents various control information, including values ​​for Type, Subtype, To DS (ToDistribution System), and From DS. The Type value indicates the frame type of the radio frame. For example, a Type value of "00" indicates that the radio frame is a management frame. A Type value of "01" indicates that the radio frame is a control frame. A Type value of "10" indicates that the radio frame is a data frame.

[0049] The content of a radio frame varies depending on the combination of the Type and Subtype values. For example, "00 / 1000 (Type value / Subtype value)" indicates that the radio frame is a beacon signal. The meanings of the To DS and From DS values ​​differ depending on their combination. For example, "00 (To DS / From DS)" indicates data between terminals within the same IBSS (Independent Basic Service Set). "10" indicates that the data frame flows from outside to this DS (Distribution System). "01" indicates that the data frame flows to the outside of this DS. "11" is used in the case of a mesh network.

[0050] The Duration field indicates the scheduled period for using the wireless line. Multiple Address fields represent the BSSID, source address, destination address, sender terminal address, receiver terminal address, etc. The Sequence Control field represents the MAC frame sequence number and the segment number used for the segment. Other control information fields include Traffic Type Identifier (TID) information. TID information can be inserted elsewhere within the wireless frame. The Frame Body field contains information corresponding to the frame type. For example, in the case of a data frame, the Frame Body field stores the data.

[0051] <1-1-2> Regarding the structure of base station 10

[0052] Figure 3 This illustrates an example of the structure of a base station 10 in the wireless system 1 according to the first embodiment. For example... Figure 3 As shown, base station 10 includes, for example, a CPU (Central Processing Unit) 11, a ROM (Read Only Memory) 12, a RAM (Random Access Memory) 13, a wireless communication component 14, and a wired communication component 15.

[0053] CPU 11 is a circuit capable of executing various programs and controlling the operation of the entire base station 10. ROM 12 is a non-volatile semiconductor memory that stores programs and control data used to control the base station 10. RAM 13 is, for example, a volatile semiconductor memory used as the operating area of ​​CPU 11. Wireless communication component 14 is a circuit used for transmitting and receiving data based on wireless signals and is connected to an antenna. Furthermore, wireless communication component 14 may include, for example, multiple communication components corresponding to multiple frequency bands. Wired communication component 15 is a circuit used for transmitting and receiving data based on wired signals and is connected to the network NW.

[0054] Figure 4This illustrates an example of the functional structure of the base station 10 in the wireless system 1 according to the first embodiment. For example... Figure 4 As shown, base station 10 includes, for example, a data processing unit 110, a link management unit 120, and wireless signal processing units 130, 140, and 150. The processing of the data processing unit 110, the link management unit 120, and the wireless signal processing units 130, 140, and 150 is implemented, for example, by a CPU 11 and a wireless communication component 14.

[0055] The data processing unit 110 is capable of performing LLC layer processing and upper layer (layer 3 to layer 7) processing on the input data. For example, the data processing unit 110 outputs data input from the server 30 via the network NW to the link management unit 120. In addition, the data processing unit 110 sends data input from the link management unit 120 to the server 30 via the network NW.

[0056] The link management unit 120 performs, for example, part of the MAC layer processing on the input data. Additionally, the link management unit 120 manages the link with the terminal 20 based on notifications from the wireless signal processing units 130, 140, and 150. The link management unit 120 includes link management information 121. This link management information 121, for example, is stored in RAM 13 and contains information about the terminal 20 wirelessly connected to the base station 10. Furthermore, the link management unit 120 includes an association processing unit 122 and an authentication processing unit 123. Upon receiving a connection request from the terminal 20 via any of the wireless signal processing units 130, 140, and 150, the association processing unit 122 executes association-related protocols. Following the connection request, the authentication processing unit 123 then executes authentication-related protocols.

[0057] Wireless signal processing units 130, 140, and 150 respectively transmit and receive data between base station 10 and terminal 20 using wireless communication. For example, wireless signal processing units 130, 140, and 150 respectively add preambles, PHY headers, etc. to the data input from link management unit 120 to create wireless frames. Furthermore, wireless signal processing units 130, 140, and 150 respectively convert the wireless frames into wireless signals and distribute the wireless signals via the antenna of base station 10. Additionally, wireless signal processing units 130, 140, and 150 respectively convert the wireless signals received via the antenna of base station 10 into wireless frames. Furthermore, wireless signal processing units 130, 140, and 150 respectively output the data contained in the wireless frames to link management unit 120.

[0058] Thus, wireless signal processing units 130, 140, and 150 can respectively perform a portion of MAC layer processing and Layer 1 processing on input data or wireless signals. For example, wireless signal processing unit 130 processes wireless signals in the 2.4 GHz band. Wireless signal processing unit 140 processes wireless signals in the 5 GHz band. Wireless signal processing unit 150 processes wireless signals in the 6 GHz band. Wireless signal processing units 130, 140, and 150 may or may not share the antenna of base station 10.

[0059] <1-1-3> Regarding the structure of terminal 20

[0060] Figure 5 This illustrates an example of the structure of the terminal 20 in the wireless system 1 according to the first embodiment. For example... Figure 5 As shown, terminal 20 includes, for example, a CPU 21, ROM 22, RAM 23, wireless communication component 24, display 25, and storage 26.

[0061] CPU 21 is a circuit capable of executing various programs and controlling the operation of the entire terminal 20. ROM 22 is a non-volatile semiconductor memory that stores programs, control data, etc., used to control the terminal 20. RAM 23 is, for example, a volatile semiconductor memory used as the operating area of ​​CPU 21. Wireless communication component 24 is a circuit used for transmitting and receiving data based on wireless signals and is connected to an antenna. Furthermore, wireless communication component 24 may include multiple communication components corresponding to multiple frequency bands. Display 25 displays, for example, a GUI (Graphical User Interface) corresponding to application software. Display 25 may function as an input interface for terminal 20. Storage 26 is a non-volatile storage device that stores, for example, the system software of terminal 20. Alternatively, terminal 20 may not have a display. For example, display 25 may be omitted in an IoT terminal.

[0062] Figure 6 This illustrates an example of the functional structure of the terminal 20 in the wireless system 1 according to the first embodiment. For example... Figure 6 As shown, terminal 20 includes, for example, a data processing unit 210, a link management unit 220, wireless signal processing units 230, 240 and 250, and an application execution unit 260. The processing of the data processing unit 210, the link management unit 220, and the wireless signal processing units 230, 240 and 250 is implemented, for example, by a CPU 21 and a wireless communication component 24.

[0063] The data processing unit 210 is capable of performing LLC layer processing and upper layer (layer 3 to layer 7) processing on the input data. For example, the data processing unit 210 outputs data input from the application execution unit 260 to the link management unit 220. Additionally, the data processing unit 210 outputs data input from the link management unit 220 to the application execution unit 260.

[0064] The link management unit 220 can perform some of the processing, such as MAC layer processing, on the input data. Furthermore, the link management unit 220 manages the link with the base station 10 based on notifications from the wireless signal processing units 230, 240, and 250. The link management unit 220 includes link management information 221. The link management information 221, for example, is stored in RAM 23 and contains information about the base station 10 wirelessly connected to the terminal 20. Additionally, the link management unit 220 includes an association processing unit 222 and an authentication processing unit 223. Upon receiving a connection request from the base station 10 via any of the wireless signal processing units 230, 240, and 250, the association processing unit 222 executes association-related protocols. The authentication processing unit 223 executes authentication-related protocols after the connection request.

[0065] Wireless signal processing units 230, 240, and 250 respectively transmit and receive data between base station 10 and terminal 20 using wireless communication. For example, wireless signal processing units 230, 240, and 250 respectively add preambles, PHY headers, etc. to the data input from link management unit 220 to create wireless frames. Furthermore, wireless signal processing units 230, 240, and 250 respectively convert the wireless frames into wireless signals and distribute the wireless signals via the antenna of terminal 20. Additionally, wireless signal processing units 230, 240, and 250 respectively convert the wireless signals received via the antenna of terminal 20 into wireless frames. Furthermore, wireless signal processing units 230, 240, and 250 respectively output the data contained in the wireless frames to link management unit 220.

[0066] Thus, wireless signal processing units 230, 240, and 250 can respectively perform a portion of MAC layer processing and Layer 1 processing on the input data or wireless signals. For example, wireless signal processing unit 230 processes wireless signals in the 2.4 GHz band. Wireless signal processing unit 240 processes wireless signals in the 5 GHz band. Wireless signal processing unit 250 processes wireless signals in the 6 GHz band. Wireless signal processing units 230, 240, and 250 may or may not share the antenna of terminal 20.

[0067] The application execution unit 260 executes applications that utilize data input from the data processing unit 210. For example, the application execution unit 260 can display application information on the display 25. Furthermore, the application execution unit 260 can perform actions based on operations of the input interface.

[0068] Regarding the wireless system 1 according to the first embodiment described above, the wireless signal processing units 130, 140, and 150 of the base station 10 are respectively configured to connect with the wireless signal processing units 230, 240, and 250 of the terminal 20. That is, the wireless signal processing units 130 and 230 can achieve wireless connection using the 2.4 GHz frequency band. The wireless signal processing units 140 and 240 can achieve wireless connection using the 5 GHz frequency band. The wireless signal processing units 150 and 250 can achieve wireless connection using the 6 GHz frequency band. In this specification, each wireless signal processing unit may be referred to as having a "STA function." That is, the wireless system 1 according to the embodiment has multiple STA functions.

[0069] <1-1-4> Detailed Structure of the Link Management Department

[0070] Figure 7 This describes the details of the channel access function of the link management unit 120 of the base station 10 in the wireless system 1 according to the first embodiment. Furthermore, the function of the link management unit 220 of the terminal 20 is, for example, the same as that of the link management unit 120 of the base station 10, and therefore its description is omitted. Figure 7 As shown, the link management unit 120 includes, for example, a data classification unit 124, transmission queues 125A, 125B, 125C, 125D and 125E, CSMA / CA (Carrier Sense Multiple Access with Collision Avoidance) execution units 126A, 126B, 126C, 126D and 126E, and a data conflict management unit 127.

[0071] The data classification unit 124 classifies the data input from the data processing unit 110. Data categories are set as follows: "LL (Low Latency)," "VO (Voice)," "VI (Video)," "BE (Best Effort)," and "BK (Background)." LL is applied to data requiring low latency. Therefore, LL data is preferably processed preferentially compared to any of the VO, VI, BE, and BK categories.

[0072] Furthermore, the data classification unit 124 inputs the classified data into any one of the transmission queues 125A, 125B, 125C, 125D, and 125E. Specifically, data for category LL is input into transmission queue 125A. Data for category VO is input into transmission queue 125B. Data for category VI is input into transmission queue 125C. Data for category BE is input into transmission queue 125D. Data for category BK is input into transmission queue 125E. Moreover, the input data for each category is accumulated in any one of the corresponding transmission queues 125A to E.

[0073] CSMA / CA execution units 126A, 126B, 126C, 126D, and 126E, respectively, confirm via carrier sensing in CSMA / CA whether wireless signals based on other terminals are not being transmitted, and wait for transmission for a predetermined time according to pre-set access parameters. Furthermore, CSMA / CA execution units 126A, 126B, 126C, 126D, and 126E retrieve data from transmission queues 125A, 125B, 125C, 125D, and 125E, respectively, and output the retrieved data to at least one of the wireless signal processing units 130, 140, and 150 via the data collision management unit 127. Thus, the wireless signal including this data is transmitted by the wireless signal processing unit (STA function) that has obtained transmission rights through CSMA / CA.

[0074] CSMA / CA execution unit 126A executes CSMA / CA for the data LL stored in transmission queue 125A. CSMA / CA execution unit 126B executes CSMA / CA for the data VO stored in transmission queue 125B. CSMA / CA execution unit 126C executes CSMA / CA for the data VI stored in transmission queue 125C. CSMA / CA execution unit 126D executes CSMA / CA for the data BE stored in transmission queue 125D. CSMA / CA execution unit 126E executes CSMA / CA for the data BK stored in transmission queue 125E.

[0075] Furthermore, access parameters can be allocated, for example, by prioritizing the transmission of wireless signals in the order of LL, VO, VI, BE, BK. Access parameters include, for example, CWmin, CWmax, AIFS, and TXOPLimit. CWmin and CWmax represent the minimum and maximum values ​​of the contention window, which serves as the waiting time to avoid collisions, respectively. AIFS (Arbitration Inter Frame Space) represents a fixed waiting time set for each access category for collision avoidance control with priority control functionality. TXOPLimit represents the upper limit of TXOP (Transmission Opportunity) corresponding to the channel occupancy time. For example, the shorter CWmin and CWmax are, the easier it is for transmission queue 125 to obtain transmission rights. The smaller the AIFS, the higher the priority of transmission queue 125. The larger the TXOPLimit value, the more data is transmitted in a single transmission.

[0076] When multiple CSMA / CA execution units 126 have obtained transmission rights with the same STA function, the data conflict management unit 127 prevents data conflicts. Specifically, the data conflict management unit 127 adjusts the transmission timing of data of different categories that have obtained transmission rights with the same STA function, sending data of the higher priority category to the STA function. For example, sometimes the STA function that has obtained transmission rights through the CSMA / CA of transmission queue 125A of LL is the same as the STA function that has obtained transmission rights through any of the other transmission queues 125B to 125E. In this case, the data conflict management unit 127 prioritizes sending the data stored in transmission queue 125A to the STA function. Similarly, in combinations of other transmission queues 125, data is sent in order based on the priority set according to the category. This prevents data assigned to the same STA function from conflicting with each other.

[0077] In this embodiment, a method in which the link management unit is equipped with a channel access function is described, but each STA function can also be equipped with a channel access function. When the link management unit is equipped with a channel access function, each STA function detects the status (idle / busy) of the corresponding link's radio channel, and the link management unit determines whether data can be transmitted (which link to use for transmission, etc.). On the other hand, when each STA function is equipped with a channel access function, each STA function only needs to independently perform carrier sensing and transmit data. In this case, channel access when using multiple links simultaneously can be performed by standardizing access parameters through interaction between multiple STA functions, or by standardizing access parameters using the link management unit. The base station 10 and the terminal 20 can simultaneously use multiple links by transmitting data between multiple STA functions based on common access parameters.

[0078] <1-2> Operation of Wireless System 1

[0079] The following describes an example of various operations associated with the multi-link wireless system 1 according to the first embodiment. In the following description, for simplicity, STA1 and STA2 of base station 10 will also be referred to as "access points (APs)". STA1 and STA2 of terminal 20 transmit wireless signals to the access points (APs), corresponding to the transmission of wireless signals to STA1 and STA2 of base station 10, respectively. When STA1 and STA2 are described separately, they represent the STA function of terminal 20.

[0080] <1-2-1> About Multilinks

[0081] Figure 8 This is a flowchart illustrating an example of multi-link processing in the wireless system 1 according to the first embodiment. For example... Figure 8 As shown, in multi-link processing, steps S10 to S16 are executed sequentially, for example.

[0082] Specifically, firstly, in step S10, terminal 20 sends a probe request to base station 10. The probe request is to confirm whether there is a signal from base station 10 around terminal 20. The Frame Control field of the probe request may contain, for example, "00 / 0100 (Type value / Subtype value)". If base station 10 receives the probe request, it executes step S11.

[0083] In step S11, base station 10 sends a probe response to terminal 20. The probe response is a signal used by base station 10 in response to a probe request from terminal 20. The Frame Control field of the probe response may contain, for example, "00 / 0101 (Type value / Subtype value)". If terminal 20 receives the probe request, it executes step S12.

[0084] In step S12, terminal 20 sends a multi-link association request to base station 10 via at least one STA function. The multi-link association request is a signal used to request the creation of multiple links from base station 10. For example, the multi-link association request is generated by the link management unit 220 of terminal 20. The Frame Control field of the multi-link association request may contain, for example, "00 / xxxx (Type value / Subtype value (xxxx is a specified value))". If the link management unit 120 of base station 10 receives the multi-link association request, it executes step S13.

[0085] In step S13, the link management unit 120 of base station 10 performs multi-link association processing using one STA function. Specifically, firstly, association processing for the first STA function is performed between base station 10 and terminal 20. Furthermore, if a radio connection (link) is established in the first STA function, the link management unit 120 of base station 10 uses the first STA function that created the link to perform association processing for the second STA function. That is, the STA function that created the link is used in the association processing of STA functions that did not create a link. If the association processing for at least two STA functions is completed, base station 10 creates multiple links and performs step S14.

[0086] Furthermore, when a link is created in the first STA function, multiple links can be created. For example, before association processing, base station 10 and terminal 20 can uniformly perform association for multiple links by notifying each other of the multi-link capability, the links to be included in the multi-link, and the operating parameters of each link. Specifically, when association begins in the first STA function, link management units 120 and 220 instruct the creation of multiple links and specify the links to be included in the multi-link. Then, link management units 120 and 220 perform association for each link and manage the aforementioned links as multiple links.

[0087] In step S14, the link management unit 120 of base station 10 updates the link management information 121. Furthermore, in this example, step S14 is executed after two links are created, but the link management information 121 can be updated each time the link status is updated, or it can be updated when multiple links are created. If multiple links are created and the link management information is updated, base station 10 executes step S15.

[0088] In step S15, base station 10 sends a multilink creation response to terminal 20. The multilink creation response is a signal used by base station 10 in response to a multilink request from terminal 20. The FrameControl field of the multilink association request may contain, for example, "00 / 0001 (Type value / Subtype value)". The link management unit 220 of terminal 20 identifies whether a multilink has been created with base station 10 based on the received multilink creation response. If terminal 20 receives the multilink creation response, it executes step S16.

[0089] In step S16, the link management unit 220 of the terminal 20 updates the link management information 221. That is, the terminal 20 records in the link management information 221 that multiple links with the base station 10 have been created. As a result, the multi-link processing of the wireless system 1 according to the first embodiment is completed, and data communication utilizing multiple links can be realized between the base station 10 and the terminal 20.

[0090] Figure 9 This illustrates an example of the link management information 121 of the wireless system 1 according to the first embodiment. Furthermore, the link management information 221 of the terminal 20 has similar information to the link management information 121 of the base station 10, therefore its description is omitted. Figure 9 As shown, the link management information 121 includes, for example, STA function, frequency band, link target ID, presence or absence of multiple links, and information on each TID.

[0091] In this example, "STA1" corresponds to the STA function using the 6GHz band, i.e., the wireless signal processing unit 150 or 250. "STA2" corresponds to the STA function using the 5GHz band, i.e., the wireless signal processing unit 140 or 240. "STA3" corresponds to the STA function using the 2.4GHz band, i.e., the wireless signal processing unit 130 or 230.

[0092] The link target ID corresponds to the identifier of terminal 20 in link management information 121 and to the identifier of base station 10 in link management information 221. In this example, multiple links using STA1 and STA2 are created. When multiple links are created, link management units 120 and 220 respectively transmit data input from the upper layer using at least one STA function link associated with the multiple links. In addition, STA1 is set for the primary link and STA2 is set for the secondary link.

[0093] A primary link is the link used as the main link in a multi-link system. A secondary link is a link used as an auxiliary link in a multi-link system. Links constituting a multi-link system are assigned to either the primary or secondary link. There can be two or more primary and secondary links. For each terminal 10 that has established a multi-link with base station 10, the link groups constituting each multi-link can be different, and the primary links can also be different. Allowing different primary links allows the optimal link between base station 10 and each terminal 20 to be set as the primary link. This can lead to improvements in wireless communication quality.

[0094] In addition to transmitting and receiving allocated data, the primary link is also used for transmitting and receiving control information associated with the operation of the multi-link. For example, the primary link is pre-configured when creating a multi-link between base station 10 and terminal 20. The STA function used as the primary link can be prioritized according to the frequency band or the radio wave strength of the link. Furthermore, the primary link settings can be appropriately changed after the creation of the multi-link through the primary link change processing described later.

[0095] The "TID" in link management information 121 indicates the association between STA functions and TID information. Each STA function transmits and receives data corresponding to the assigned TID information. For example, TIDs 1 to 3 correspond to any one of LL, VO, VI, BE, and BK, respectively. A single type of traffic, i.e., a single TID, can be associated with one STA function or multiple STA functions. In this example, TID 1 is assigned to both STA1 and STA2. TID 2 is assigned to STA1. TID 3 is assigned to STA2.

[0096] When establishing multiple links between base station 10 and terminal 20, a communication flow corresponding to the association between this traffic and STA function is pre-defined. For example, the link management unit 220 of terminal 20 determines the association between traffic and STA function and sends a request to the link management unit 120 of base station 10. Moreover, base station 10 responds to the request and determines the association between traffic and STA function.

[0097] Furthermore, traffic is configured to be distributed evenly across multiple links constituting a multi-link system. This is not a limitation; traffic of similar types (priority / non-priority, etc.) can be aggregated onto a single link constituting the multi-link system. Additionally, as STA functions are associated with traffic, for example, voice is associated with the 2.4GHz band, and video is associated with 5G. Thus, frequencies for transmission and reception are preferably allocated based on the type of information being processed and the data capacity.

[0098] <1-2-2> Data transmission in multi-link scenarios

[0099] Figure 10 This illustrates an example of a data transmission method for a base station 10 in a wireless system 1 according to the first embodiment when there are multiple links. For example... Figure 10 As shown, if base station 10 obtains data from the upper layer, it will execute the processing steps S20 to S22 in sequence.

[0100] Specifically, firstly, in step S20, the link management unit 120 obtains the TID information corresponding to the data. In other words, the link management unit 120, for example, refers to the MAC header in the radio frame obtained from the upper layer to confirm whether the TID information contained in the MAC header is any one of LL, VO, VI, BE, or BK. Thus, the link management unit 120 can determine which TID corresponds to the communication flow of the data.

[0101] Next, in step S21, the link management unit 120 acquires the STA function corresponding to the confirmed TID information. At this time, the link management unit 120 confirms the association between the TID information and the STA function by referring to the link management information 121. Furthermore, in step S21, the number of STA functions acquired by the link management unit 120 can be one or more.

[0102] Next, in step S12, the link management unit 120 outputs data to the acquired STA functions. When one STA function is associated with the output data (traffic), the data is transmitted serially using that one STA function. Conversely, when multiple STA functions are associated with the traffic, the data is transmitted in parallel using multiple STA functions.

[0103] Furthermore, when transmitting one type of traffic in parallel, data allocation and rearrangement are performed between the link management unit 120 of base station 10 and the link management unit 220 of terminal 20. Data allocation is performed by the link management unit on the transmitting side, and data rearrangement is performed by the link management unit on the receiving side. For example, the link management unit on the transmitting side adds a flag indicating multiple links and an identification number to the radio frame. The link management unit on the receiving side performs data rearrangement based on the added flag and identification number.

[0104] Furthermore, in the wireless system 1 according to the first embodiment, when multiple data are received from the upper layer, the link management unit can combine the received multiple data to perform aggregation. Multi-link aggregation can be used as a selection function that allows users to choose whether or not to perform the selection.

[0105] <1-2-3> Regarding the processing of primary changes

[0106] First, let's illustrate an example of the conditions for performing a basic change process. Figure 11 This is a flowchart illustrating an example of the execution conditions for the primary change processing of the wireless system 1 according to the first embodiment. For example... Figure 11 As shown, firstly, the link management unit 120 monitors the interference status of the OBSS (Overlapping BSS) of the primary link and the interference status of the OBSS of the secondary link (step S30).

[0107] Furthermore, the link management unit 120 confirms whether the interference of the primary link's OBSS is greater than the interference of the secondary link's OBSS (step S31). For example, the link management unit 120 confirms whether the channel occupancy time for the primary link's OBSS is greater than the channel occupancy time for the secondary link's OBSS. In addition, factors other than channel occupancy time can be used to evaluate interference, as long as factors that keep the channel busy for at least the period excluding signal interaction from its own BSS are used. For example, the magnitude of interference power, interference from other communication systems, and the presence of noise power can be used to evaluate interference.

[0108] If the interference of the OBSS on the primary link is greater than that on the secondary link (YES in step S31), the link management unit 120 performs a primary change process (step S32). If the primary change process is performed, the primary link is changed to another link used in multiple links. That is, the primary link is switched to a secondary link.

[0109] If the interference of the primary link's OBSS is less than or equal to the interference of the secondary link's OBSS (NO in step S31), or if the primary change processing in step S32 has been completed, the link management unit 120 terminates a series of processes related to the execution of the primary change processing. The link management unit 120 can periodically execute the processes described above in steps S30 to S32.

[0110] Furthermore, primary change processing can be appropriately performed based on continuous monitoring of the OBSS interference status. Additionally, the triggering condition for performing primary change processing is not limited to the OBSS interference status. Primary change processing can be performed based on the radio wave strength of each link. In this case, the link management unit 120, for example, confirms whether the radio wave strength of the primary link is weaker than that of the secondary link.

[0111] Next, refer to Figure 12 A specific example of primary change processing is provided. Figure 12 This is a flowchart illustrating a specific example of the initial change processing of the wireless system 1 according to the first embodiment. Furthermore, in the initial state of this example, it is set... Figure 9 The link status is shown. Furthermore, STA1 and STA2 are set for the primary link and the secondary link respectively.

[0112] If in Figure 9 In the link state shown, if the access point AP sends data TID#2 to the terminal 20, then the STA1 of the terminal 20 receives the data (step S40). Furthermore, the STA1 of the terminal 20 will send a notification ("ACK: Acknowledge") to the access point AP to acknowledge receiving the data (step S41).

[0113] If the link management unit 120 of base station 10 detects that the condition is met... Figure 11 If the conditions specified in the description are met, a wireless signal requesting a change of the primary link is sent to terminal 20 via the primary link (STA1) (step S42). If STA1 of terminal 20 receives the wireless signal, the link management unit 220 of terminal 20 confirms whether a change of the primary link can be performed.

[0114] Furthermore, if a change to the primary link is possible, the link management unit 220 of terminal 20 sends an affirmative response (“OK”) to the access point AP via STA1 or STA2 (step S43). In addition, if a change to the primary link is not possible, the link management unit 220 of terminal 20 can send a negative response (“NO”) to the access point AP via STA1 or STA2.

[0115] After the processing in step S43, the link management unit 120 of base station 10 and the link management unit 220 of terminal 20 respectively change the primary link from STA1 to STA2 (step S44). Specifically, STA1 is changed from a primary link to a secondary link, and STA2 is changed from a secondary link to a primary link.

[0116] After the primary link change is performed in step S44, if data with TID#2 is sent from the access point AP to the terminal 20, the STA2 of the terminal 20 receives the data (step S45). Furthermore, the STA2 of the terminal 20 will send an ACK signal (“ACK”) to the access point AP upon receiving the data (step S46).

[0117] Figure 13 Indicates based on Figure 12 This is an example of a change in the link management information 121 during the initial change processing described in the documentation. For example... Figure 13 As shown, the primary / secondary settings and TID settings of the two links constituting the multi-link are alternately performed by executing primary change processing.

[0118] Specifically, through primary change processing, STA1 is changed from a primary link to a secondary link, and the TIDs assigned to STA1 are changed from TID #1 and 2 to TID #1 and 3. On the other hand, STA2 is changed from a secondary link to a primary link, and the TIDs assigned to STA2 are changed from TID #1 and 3 to TID #1 and 2.

[0119] As described above, the primary link configured in a multi-link system can be changed through a primary change process performed based on specified conditions. Furthermore, the TID associated with the primary link can be changed simultaneously with the primary link change. Moreover, settings related to the association between traffic and TID information can be maintained even when the primary link is changed. That is, in the primary change process, it is sufficient that at least the STA function for sending and receiving control information for the multi-link system is switched to the new STA function configured for the primary link.

[0120] Figure 14 and Figure 15 This section shows a specific example of a wireless frame used in the initial change processing of the wireless system 1 according to the first embodiment. Figure 14 This corresponds to the radio frame sent when the access point (AP) requests a change in the primary link from the terminal 20. Figure 15 This corresponds to the radio frame sent back to the access point (AP) by terminal 20 in response to a change request for the primary link.

[0121] like Figure 14 As shown, the Frame Body of a radio frame requesting a change to the primary link includes, for example, a Terminal Identifier (AID), a primary change request, and an identifier for the next primary link. The Link Management Unit 220 of the terminal 20 corresponding to the AID determines whether a change to the primary link can be performed based on the "primary change request" and by referring to the "identifier for the next primary link".

[0122] When a primary link change is possible, the frame body of the radio frame corresponding to the response to the primary change request, i.e., the affirmative response, is as follows: Figure 15 (a) contains “Ready”. “Ready” corresponds to the bit that indicates the ability to make a primary change.

[0123] On the other hand, in the absence of a primary link modification, the frame body of the radio frame corresponding to the response to the primary link modification request, i.e., the negative response, is as follows: Figure 15 (b) includes "No" and "Reason". "No" corresponds to the bit indicating that the primary change cannot be made. "Reason" corresponds to the bit indicating the reason why the primary change cannot be made. In addition, the "Reason" in the radio frame corresponding to the response to the primary change request can be omitted.

[0124] <1-3> Effects of the first embodiment

[0125] The wireless system 1 according to the first embodiment described above can improve communication stability in multi-link scenarios. The effects of the wireless system 1 according to the embodiment will now be explained in detail.

[0126] Base stations and terminals using wireless LANs sometimes have multiple STA functions configured for each bandwidth used, such as 2.4GHz, 5GHz, and 6GHz. In such wireless systems, a wireless connection is established by selecting one of the multiple STA functions, enabling data communication between the base station and the terminal. In this case, for any unselected STA function, even if a base station with a bandwidth corresponding to that STA function exists, it becomes unused.

[0127] In contrast, the wireless system 1 according to the first embodiment flexibly utilizes the multiple STA functions of the base station 10 and the terminal 20 respectively to create multiple links between the base station 10 and the terminal 20. Data communication based on multiple links can simultaneously utilize multiple bandwidths, fully and flexibly utilizing the functions of the wireless LAN device. As a result, the wireless system 1 according to the embodiment can achieve effective communication and improve communication speed.

[0128] Furthermore, as a method of using multiple links, it is considered to set up a primary link for transmitting and receiving information associated with the control of the multiple links. By setting up the primary link, the wireless system 1 can simplify the communication between the link management unit 120 of the base station 10 and the link management unit 220 of the terminal 20.

[0129] On the other hand, in multi-link systems, communication stability can vary depending on each link that makes up the multi-link system. For example, interference conditions based on OBSS and the intensity of radio waves can change depending on the frequency band used. Therefore, when a primary link is set up for a multi-link system, it is possible for the communication quality of the primary link to be lower than that of the secondary links. The primary link is used for the control of the entire multi-link system, and therefore preferably has higher communication quality than other links.

[0130] Therefore, the wireless system 1 according to the first embodiment switches between the primary link and the secondary link based on the communication quality of each link used in the multi-link system. For example, the link management unit 120 of the base station 10 monitors the interference status of each link constituting the multi-link system. Furthermore, if the link management unit 120 detects that "the interference of the primary link's OBSS is greater than the interference of the secondary link's OBSS", it switches between the primary link and the secondary link.

[0131] As described above, by appropriately modifying the primary link based on prescribed conditions, a state with high communication quality for the primary link is maintained. As a result, the wireless system 1 according to the first embodiment can improve the stability of multiple links. In other words, the wireless system 1 according to the first embodiment can improve the communication quality between the base station 10 and the terminal 20 in the case of multiple links.

[0132] <2> Second Implementation Method

[0133] The wireless system 1 according to the second embodiment has the same structure as that according to the first embodiment. Furthermore, the wireless system 1 according to the second embodiment is appropriately configured for multi-link power saving for secondary links, and in the primary change processing, the switching of the primary link and the switching of multi-link power saving are performed uniformly. Hereinafter, the differences between the wireless system 1 according to the second embodiment and the first embodiment will be explained.

[0134] <2-1> Operation of Wireless System 1

[0135] <2-1-1> Regarding power saving in multi-link systems

[0136] In the wireless system 1 according to the second embodiment, multiple operating modes are prepared for each STA function. Examples of operating modes for STA functions include an active mode, an intermittent operating mode, and an operation pause mode. The active mode maintains an Awake state through the ST1A function of terminal 20, corresponding to a state where wireless signals can be transmitted and received at any time. The intermittent operating mode repeatedly forms an Awake state and a Doze state through the STA function of terminal 20, corresponding to a state where actions are performed intermittently. The operation pause mode maintains a Doze state through the STA function of terminal 20, corresponding to a state where wireless signals cannot be transmitted or received. Multiple STA functions constituting a multi-link include at least one link with an active mode or an intermittent operating mode. Other links constituting the multi-link can be set to any one of the active mode, intermittent operating mode, and operation pause mode.

[0137] Furthermore, the Awake state corresponds to the state where wireless signals can be transmitted and received. The Dose state corresponds to the state where wireless signals cannot be transmitted and received. In the Dose state, the power supply to the line associated with the STA function is appropriately cut off. Therefore, the power consumption of the STA function decreases in the order of active mode, intermittent operation mode, and operation pause mode. In addition, base station 10 or terminal 20 can be used for communication, but there may also be links not included in the link group of multiple links between them (disabled links). Hereinafter, for the sake of simplicity, the links in active mode or intermittent operation mode, that is, the links that can communicate, are referred to as "STA function (link) in Awake state". The links in operation pause mode, that is, the links in the power-saving state where communication is not possible, are referred to as "STA function (link) in Dose state".

[0138] Regarding the multi-link wireless system 1 according to the second embodiment, the STA function set for the primary link is, for example, set to either an active mode or an intermittent operation mode. On the other hand, the STA function set for the secondary link can be set to either an active mode, an intermittent operation mode, or an operation pause mode. For example, when the terminal 20 is in multi-link operation, setting the secondary link to the operation pause mode can save power during operation. Hereinafter, the state of multi-link operation with the secondary link set to the operation pause mode is referred to as "multi-link power saving". Furthermore, when multi-link operation is created through multi-link processing, the initial state of the secondary link can be set to either an active mode, an intermittent operation mode, or an operation pause mode.

[0139] Figure 16 This illustrates an example of a multi-link power-saving method for the wireless system 1 according to the second embodiment. Furthermore, in the initial state of this example, it is set... Figure 9 The link status is shown. Furthermore, STA1 and STA2 are both set to active mode. For example... Figure 16As shown, when STA1 and STA2 are in active mode, they can simultaneously send and receive data from TID#2 and TID#3.

[0140] If the link management unit 220 of terminal 20 detects that the first condition is met, it sends a Doze transition notification signal to the access point AP using the primary link (STA1) (step S50). The first condition corresponds, for example, to the case where traffic is not accumulated on the secondary link (STA2). The Doze transition notification signal is a signal that notifies a transition to the Doze state, corresponding to "disable" in the illustration. Terminal 20 can obtain information about this traffic by receiving beacon signals from base station 10 using at least one of STA1 and STA2.

[0141] If STA1 of base station 10 receives a Doze transition notification signal, the link management unit 120 of base station 10 checks whether a transition from the secondary link to the operation pause mode is permitted. Furthermore, if a transition from the secondary link to the operation pause mode is permitted, the link management unit 120 of base station 10 sends an affirmative response (“OK”) to terminal 20 via STA1 or STA2 (step S51). Conversely, if a transition from the secondary link to the operation pause mode is not permitted, the link management unit 120 of base station 10 may send a negative response (“NO”) to base station 10 via STA1 or STA2.

[0142] If terminal 20 receives a positive response in step S51, the link management unit 220 of terminal 20 changes STA2, which is set as a secondary link, to the action pause mode (step S52). As a result, STA1 and STA2 of terminal 20 become Awake and Doze states, respectively. At this time, the multi-link becomes capable of only sending and receiving data of TID#2.

[0143] Then, if the link management unit 220 of terminal 20 detects that the second condition is met, it sends an Awake transition request signal to the access point AP via the primary link (STA1) (step S53). The second condition corresponds, for example, to the case where traffic has accumulated on the secondary link (STA2). The Awake transition request signal is a signal requesting a transition to the Awake state, corresponding to "enable" in the illustration. Terminal 20 can obtain information about this traffic by receiving the beacon signal from base station 10 using the activated STA1.

[0144] If STA1 of base station 10 receives an Awake transition request signal, the link management unit 120 of base station 10 sends an affirmative response (“OK”) to terminal 20 via STA1 corresponding to the primary link (step S54). If terminal 20 receives the affirmative response in step S54, the link management unit 220 of terminal 20 changes STA2, which is set as a secondary link, to active mode (step S55). Thus, STA1 and STA2 of terminal 20 both enter the Awake state. As a result, the multi-link becomes, for example, capable of transmitting and receiving any of TID#1 to 3.

[0145] Figure 17 Indicated based on Figure 16 This is an example of a change in link management information 121 in the multi-link power-saving usage example described in the text. For example... Figure 17 As shown, multi-link power saving is achieved through the application of Doze transition notification signals and Awake transition request signals. Specifically, after setting up multiple links, terminal 20 sends a Doze transition notification signal to base station 10 to cause the secondary link in the active mode to switch to the action-off mode, and sends an Awake transition request signal to cause the secondary link in the action-off mode to switch to the active mode.

[0146] Thus, in the wireless system 1 according to the second embodiment, the base station 10 and the terminal 20 can change the mode of the secondary link by sending Awake transition request / Doze transition notification signals. The Awake transition request signal is transmitted using the primary link or another activated link. The Doze transition notification signal is transmitted using the primary link or a stopped link (a link transitioning to an action-pause mode).

[0147] Furthermore, an Awake transition request signal and a Doze transition notification signal can be sent from either the access point (AP) or the terminal 20. When the first and second conditions are based on traffic stagnation (buffered state), for example, a change in the action mode is triggered when the traffic accumulated in the buffer exceeds a predetermined threshold. Additionally, an intermittent action mode can be applied to the primary link. In this case, the primary link operates in a manner that allows it to receive beacon signals containing control information for multiple links.

[0148] <2-1-2> Regarding the processing of primary changes

[0149] Figure 18 This is a flowchart illustrating a specific example of the initial change processing of the wireless system 1 according to the second embodiment. Furthermore, in the initial state of this example, it is set... Figure 17The link states shown are in Doze state. That is, STA1 and STA2 are set to Awake state and Doze state respectively, and the multi-link configuration is set to be able to send and receive data of TID#2 only.

[0150] If the link management unit 120 of base station 10 detects that the condition is met... Figure 11 If the conditions specified in the description are met, a wireless signal requesting a change of the primary link is sent to the terminal 20 using the primary link (STA1) in active mode (step S60). If the STA1 of the terminal 20 receives the wireless signal, the link management unit 220 of the terminal 20 confirms whether a change of the primary link can be performed.

[0151] Furthermore, if a change to the primary link is possible, the link management unit 220 of terminal 20 sends an affirmative response (“OK”) to the access point AP via STA1 or STA2 (step S61). In addition, if a change to the primary link is not possible, similar to the first embodiment, the link management unit 220 of terminal 20 can send a negative response (“NO”) to the access point AP via STA1 or STA2.

[0152] After the processing in step S61, the link management unit 220 first changes the secondary link from the Doze state to the Awake state (step S62). At this time, the secondary link can be set to either the active mode or the intermittent operation mode.

[0153] Furthermore, the access point (AP) sends a beacon signal to the terminal 20 containing countdown information indicating the timing of the change in the primary link (step S63). The “countdown #1 to n” shown in the figure corresponds to the n counts of beacon signals sent to the terminal 20 up to the time the primary link has been changed.

[0154] If the countdown based on multiple beacon signals is completed, the link management unit 120 of base station 10 and the link management unit 220 of terminal 20 respectively change the primary link from STA1 to STA2 (step S64). Specifically, STA1 is changed from the primary link to the secondary link, and STA2 is changed from the secondary link to the primary link. Furthermore, in the second embodiment, along with the change of the primary link, STA1, which has been changed to the secondary link, is set to the Doze state of the operation rest mode. As a result, the multiple links are configured to be able to use STA2 to transmit and receive data of TID#2, and to suppress the power consumption of STA1.

[0155] Figure 19 Indicates based on Figure 18 This is an example of a change in the link management information 121 during the initial change processing described in the documentation. For example... Figure 19As shown, the primary / secondary settings, TID settings, and action mode settings of the two links constituting the multi-link are replaced respectively by performing primary change processing.

[0156] Specifically, through a primary change process, STA1 is changed from a primary link in active mode (Awake state) to a secondary link in doze mode. On the other hand, STA2 is changed from a secondary link in doze mode to a primary link in active mode (Awake state). Furthermore, when the primary link is changed, settings related to traffic and TID information can be changed, or these settings can be maintained. Other operations of the wireless system 1 according to the second embodiment are the same as in the first embodiment.

[0157] <2-2> Effects of the second implementation method

[0158] Regarding the power consumption of multiple links, since they are used by multiple STA functions, the power consumption is higher compared to a single link using only one STA function. Therefore, from the viewpoint of power saving, it is preferable to use a single link when there is no traffic congestion and to use multiple links when there is traffic congestion. Furthermore, from the viewpoint of low latency, when there is accumulated LL traffic, it is preferable to set up a link exclusively used by LL traffic. In other words, it is preferable to temporarily set up a link for LL traffic and a link for traffic other than LL traffic.

[0159] Therefore, the wireless system 1 according to the second embodiment switches between single link and multiple links for data communication after multiple links are created. Specifically, after multiple links are created, the link management unit 120 of the base station 10 and the link management unit 220 of the terminal 20 control the start / stop of the secondary links. Here, "link start" corresponds to the case where the operation is set to active mode, and "link stop" corresponds to the case where the operation is set to idle mode.

[0160] For example, from an energy-saving perspective, when traffic is not congested, only one link (the primary link) of a multi-link system is set to active mode, while the other links (secondary links) are set to inactive mode. In this case, the multi-link system essentially performs data communication in the same state as a single link. On the other hand, when traffic is congested, high-speed data communication utilizing the multiple links of the multi-link system is performed.

[0161] Furthermore, according to the Low Latency perspective, when there is no accumulated Low Latency traffic, multiple links can be used in a single-link state by flexibly utilizing the action pause mode. On the other hand, when there is accumulated Low Latency traffic, multiple links constituting multiple links can be used, for example, one of the multiple links can be allocated as a dedicated link for Low Latency traffic.

[0162] As described above, by utilizing a low-power operation pause mode based on the traffic status, the wireless system 1 according to the second embodiment can suppress power consumption. Furthermore, the wireless system 1 according to the second embodiment can protect the traffic of the LL by controlling the start / stop of the link based on the presence or absence of traffic on the LL.

[0163] Furthermore, in the case of a combination of multiple links and an action pause mode, the primary change processing described in the first embodiment can also be performed. On the other hand, if the base station 10 unilaterally instructs the primary link to switch for the terminal 20 with a secondary link having an action pause mode, it is possible that the synchronization of the link status (primary / secondary) cannot be achieved on the terminal 20 side.

[0164] Therefore, in the wireless system 1 according to the second embodiment, the link management unit 120 of the base station 10 transmits and receives signals for controlling link start / stop before performing a primary link handover with the terminal 20. This signal transmission and reception corresponds, for example, to a countdown using a beacon signal. Furthermore, since the primary link handover is performed using the primary link before the handover, the link management unit 120 of the base station 10 and the link management unit 220 of the terminal 20 can perform primary change processing regardless of whether an operation pause mode is used.

[0165] Therefore, the link management unit 220 of terminal 20 can know the switching timing of the primary link based on the transmission and reception of signals. As a result, the wireless system 1 according to the second embodiment can reliably perform the primary change processing when using the operation pause mode. Furthermore, the wireless system 1 according to the second embodiment also applies the operation pause mode of the secondary link along with the switching of the primary link, thus suppressing power consumption when using multiple links.

[0166] Furthermore, when multiple terminals 20 are connected to the base station 10 and one of the terminals 20 has LL traffic, the transmission and reception of signals in the primary handover process described above can be performed to perform exclusive control of the links of other terminals 20. In this case, the base station 10 can improve the communication quality of the terminal 20 with LL traffic by changing the link settings of the other terminal 20.

[0167] <3> Third Implementation Method

[0168] The wireless system 1 according to the third embodiment has the same structure as that according to the first embodiment. Furthermore, after establishing multiple links, the wireless system 1 according to the third embodiment appropriately performs channel changes within the same frequency band. Hereinafter, the differences between the wireless system 1 according to the third embodiment and those according to the first and second embodiments will be explained.

[0169] <3-1> Operation of Wireless System 1

[0170] <3-1-1> About the Channel

[0171] Figure 20 This illustrates an example of the frequency band used in the wireless communication of the wireless system 1 according to the third embodiment. For example... Figure 20 As shown, in wireless communication, frequency bands such as 2.4 GHz, 5 GHz, and 6 GHz are used. Each frequency band contains multiple channels. In this example, it is assumed that the 2.4 GHz, 5 GHz, and 6 GHz bands each contain at least three channels, CH1, CH2, and CH3. Communication using each channel CH is achieved by establishing associated STA functions.

[0172] <3-1-2> Regarding Channel Change Processing

[0173] First, an example of the conditions for performing channel change processing will be explained. Figure 21 This is a flowchart illustrating an example of the execution conditions for channel change processing in the wireless system 1 according to the third embodiment. For example... Figure 21 As shown, firstly, the link management unit 120 monitors the interference status of the OBSS of each channel in the frequency band of the secondary link (step S70).

[0174] Furthermore, the link management unit 120 confirms whether the interference of the OBSS of the channel in use is greater than the interference of the OBSS of other channels (step S71). For example, the link management unit 120 confirms whether the channel occupancy time for the OBSS of the channel in use is greater than the channel occupancy time for other channels. In addition, factors other than channel occupancy time can be used to evaluate interference, as long as factors that make the channel busy during periods other than the interaction of its own BSS signals are used. For example, the magnitude of interference power, interference from other communication systems, and the presence of noise power can be used to evaluate interference.

[0175] If the interference of the OBSS of the channel in use is greater than the interference of the OBSS of other channels (YES in step S71), the link management unit 120 performs a channel change (step S72). If a channel change is performed, the channel used in the secondary link is changed to another channel in the same frequency band.

[0176] If the interference of the OBSS of the channel in use is less than or equal to the interference of the OBSS of other channels (NO in step S71), or if the channel change in step S72 has been completed, the link management unit 120 ends a series of processes related to the channel change process. The link management unit 120 can periodically execute the processes described above in steps S70 to S72.

[0177] Furthermore, channel change processing can be appropriately performed based on the continuous monitoring results of the OBSS interference status. Additionally, the triggering condition for performing channel change processing is not limited to the OBSS interference status. Channel change processing can be performed based on the radio wave strength of each link. In this case, the link management unit 120, for example, confirms whether the radio wave strength of the channel in use is weaker than the radio wave strength of other channels in the same frequency band. Alternatively, the base station 10 may not directly monitor the interference status, but the terminal 20 may monitor the interference status and send the monitoring results to the base station 10. In this case, the base station 10 uses the monitoring results to perform channel change processing.

[0178] Next, refer to Figure 22 A specific example of channel change processing is explained. Figure 22 This is a flowchart illustrating a specific example of channel change processing in the wireless system 1 according to the third embodiment. Furthermore, in the initial state of this example, relative to... Figure 9 The link status shown indicates that multiple links are configured based on channel CH1 of STA1 and channel CH2 of STA2.

[0179] If data with TID#3 is sent from the access point AP to the terminal 20 in this state, the STA2 of the terminal 20 receives the data (step S80). Furthermore, the STA2 of the terminal 20 will send a radio signal (“ACK”) notifying the access point AP that the data has been received (step S81).

[0180] If the link management unit 120 of base station 10 detects that the condition is met... Figure 21 If the conditions specified in the description are met, a wireless signal requesting a channel change is sent to terminal 20 via the primary link (step S82). If STA1 of terminal 20 receives the wireless signal, the link management unit 220 of terminal 20 confirms whether a channel change can be performed.

[0181] Furthermore, if a channel change is possible, the link management unit 220 sends an affirmative response (“OK”) to the access point AP via STA1 or STA2 (step S83). Conversely, if a channel change is not possible, the link management unit 220 of the terminal 20 sends a negative response (“NO”) to the access point AP via STA1 or STA2.

[0182] After the processing in step S83, the link management unit 120 of base station 10 and the link management unit 220 of terminal 20 respectively change the 5GHz channel used as a secondary link from, for example, "CH2" to "CH3" (step S84).

[0183] After the channel change in step S84 is performed, if data TID#3 is sent from the access point AP to the terminal 20, the STA2 of the terminal 20, which has been changed to channel CH3 in 5 GHz, receives the data (step S85). Furthermore, the STA2 of the terminal 20 will send an ACK ("ACK") notification to the access point AP indicating that the data has been received (step S86).

[0184] Figure 23 Indicates based on Figure 22 This is an example of a change in the link management information 121 during channel change processing, as described in the diagram. Figure 23 As shown, the channel ID corresponding to the secondary link among the multiple links constituting a multi-link is changed by performing channel change processing.

[0185] Specifically, the channel of STA2, which is configured as a secondary link and uses the 5GHz band, is changed from "CH2" to "CH3" through channel change processing. In addition, the settings related to traffic and TID information can be changed when the channel is changed, or the settings can be maintained.

[0186] Figure 24 This illustrates a specific example of a wireless frame used in the channel change processing of the wireless system 1 according to the third embodiment. Figure 24 This corresponds to the radio frame sent when the access point (AP) requests a change of channel for the secondary link from the terminal 20.

[0187] like Figure 24 As shown, the frame body of the radio frame requesting channel change processing includes, for example, a terminal identifier (AID), a channel change request, an identifier of the target secondary link, and the following channel ID. The link management unit 220 of the terminal 20 corresponding to this AID determines whether a channel change for the secondary link can be performed based on the "channel change request," referring to the "identifier of the target secondary link" and the "following channel ID." Furthermore, in the response to the channel change request, for example, the method described in the first embodiment is used... Figure 15 The same wireless frame. Other operations of the wireless system 1 involved in the third embodiment are the same as those in the first embodiment.

[0188] <3-2> Effects of the third implementation method

[0189] In the first embodiment, an example is shown where the primary link is switched based on the communication quality of different frequency bands. However, sometimes the communication quality differs between channels within the same frequency band. For example, regarding the communication quality of the secondary link, within the same frequency band, interference conditions based on OBSS, radio wave intensity, etc., may change depending on the channel used. Therefore, regarding the wireless system 1, it is sometimes preferable to switch the channel of the secondary link used as a secondary link when using the primary link as the main line for data communication in a multi-link configuration.

[0190] Therefore, the wireless system 1 according to the third embodiment switches the channel used in the secondary link based on the communication quality of each channel used in the multiple links. For example, the link management unit 120 of the base station 10 monitors the interference status of each channel in the frequency band (2.4 / 5 / 6 GHz band, etc.) of the secondary link. Moreover, if the link management unit 120 detects, for example, "the interference of the OBSS of the channel in use is greater than the interference of the OBSS of other channels", it switches the channel of the secondary link to the channel with the least interference in the same frequency band.

[0191] As described above, in the wireless system 1 according to the third embodiment, the channel used in the secondary link is appropriately changed based on predetermined conditions, thereby maintaining a state of high communication quality for the secondary link. As a result, the wireless system 1 according to the third embodiment can improve the communication quality of multiple links.

[0192] Furthermore, as a set of conditions for performing channel change processing, all parameters related to the communication quality of each link can be used. Additionally, while the third embodiment illustrates changing the channel of a secondary link, the channel of the primary link can also be changed through channel change processing.

[0193] Furthermore, when multiple terminals 20 are connected to the base station 10, the base station 10 can uniformly perform channel change processing for all of these terminals 20. In this case, the link management unit 120 of the base station 10, for example, changes the channel of the secondary link upon receiving a positive response from all terminals 20 that are subject to the channel change.

[0194] <3-3> Variations of the third embodiment

[0195] The wireless system 1 described in the third embodiment is merely an example, and various modifications are possible. The first and second modifications of the third embodiment will be described below in sequence.

[0196] <3-3-1> First variation of the third embodiment

[0197] The first variation of the third embodiment is a combination of the signal transmission and reception of the third embodiment and the second embodiment. Figure 25This is a flowchart illustrating a specific example of the channel change processing in the first variation of the third embodiment. Figure 25 The flowchart shown has in Figure 22 The flowchart shown has an additional step S90 structure between steps S83 and S84.

[0198] Specifically, the access point (AP) indicates a channel change to the terminal 20 (step S82), and the terminal 20 sends a positive response to the AP (step S83). Then, the AP sends a beacon signal to the terminal 20 containing a countdown information indicating the timing of the channel change in the secondary link (step S90). The “countdown #1 to n” shown in the diagram corresponds to the n counted beacon signals sent to the terminal 20 up to the channel change in the secondary link.

[0199] If the countdown based on multiple beacon signals is completed, the link management unit 120 of base station 10 and the link management unit 220 of terminal 20 respectively change the channel of the secondary link (STA2) from CH2 to CH3 (step S84). The other structures and operations of the wireless system 1 involved in the second variation of the third embodiment are the same as those in the third embodiment.

[0200] As described above, in the wireless system 1 according to the first variation of the third embodiment, countdown information is sent before changing the channel. In other words, the access point (AP) performs signal transmission and reception with the terminal 20 before performing channel switching of the secondary link. As a result, the link management unit 220 of the terminal 20 can know the channel switching timing based on the signal transmission and reception, and can reliably perform channel switching.

[0201] Furthermore, the channel change for signal transmission and reception in the first variation of the third embodiment can be performed on multiple terminals 20 connected to the access point (AP). By using the signal transmission and reception in the first variation of the third embodiment, the access point (AP) can synchronously switch the channels of multiple terminals 20 within the BSS. This operation is effective, for example, in the case of exclusive control of link creation as described in the effects of the second embodiment.

[0202] <3-3-2> Second variation of the third embodiment

[0203] The second variation of the third embodiment is a combination of the multi-link power saving of the third embodiment and the second embodiment. Figure 26 This is a flowchart illustrating a specific example of the channel change processing in the second variation of the third embodiment. In the initial state of this example, relative to... Figure 9The link states shown are configured with multiple links based on channel CH1 of STA1 and channel CH2 of STA2. STA1 and STA2 are respectively set to Awake state (active mode or intermittent action mode) and Doze state (action pause mode).

[0204] If the link management unit 120 of base station 10 detects that the condition is met... Figure 21 Under the conditions specified in the description, the primary link (STA1) in the Awake state is used to send data to terminal 20, such as... Figure 26 The wireless signal requesting a channel change is shown (step S100). If STA1 of terminal 20 receives the wireless signal, the link management unit 220 of terminal 20 confirms whether a channel change for the secondary link can be performed.

[0205] Furthermore, when it is possible to change the channel of the secondary link, the link management unit 220 of the terminal 20 sends an affirmative response (“OK”) to the access point AP via STA1 (step S101). In addition, when it is not possible to change the channel of the secondary link, similar to the third embodiment, the link management unit 220 of the terminal 20 can send a negative response (“NO”) to the access point AP via STA1.

[0206] After the processing in step S101, the link management unit 120 of base station 10 and the link management unit 220 of terminal 20 change the channel of the secondary link from CH2 to CH3 while the secondary link is in the Doze state of the operation pause mode (step S102).

[0207] Then, if the link management unit 220 of terminal 20 detects that the conditions described in the second embodiment are met, it sends an Awake transition request signal to the access point AP via the primary link (STA1) (step S103). If STA1 of base station 10 receives the Awake transition request signal, the link management unit 120 of base station 10 sends an affirmative response (“OK”) to terminal 20 via the primary link (step S104).

[0208] If terminal 20 receives a positive response in step S104, the link management unit 220 of terminal 20 changes STA2, which is configured as a secondary link, to active mode (step S105). At this time, the link management unit 220 controls STA2 based on the settings changed through the process in step S102. That is, it wakes up STA2 of terminal 20 in a communication-enabled state using the 5GHz channel CH3.

[0209] That is, after the channel change in step S105 is performed, if data TID#3 is sent from the access point AP to the terminal 20, the STA2 of the terminal 20, which has been changed to the 5GHz channel CH3, receives the data (step S106). Furthermore, the STA2 of the terminal 20 sends a wireless signal (“ACK”) to the access point AP to notify that the data has been received (step S107). The other structures and operations of the wireless system 1 involved in the second variation of the third embodiment are the same as those in the third embodiment.

[0210] As described above, in the second variation of the third embodiment, channel change processing is performed when the secondary link is in an operation pause mode. If the access point AP unilaterally performs a channel change while the secondary link is in an operation pause mode, the awakened STA function may not perform its operation on the appropriate channel. On the other hand, in the second variation of the third embodiment, the access point AP notifies the terminal 20 of the channel change of the secondary link using the primary link.

[0211] Therefore, the wireless system 1 according to the second variation of the third embodiment can reliably perform channel change processing targeting the secondary link during the operation pause mode. Furthermore, the STA function awakened from the operation pause mode uses the link management unit 220 to confirm the association between the STA function and the channel, thereby enabling communication on the appropriate channel.

[0212] <4> Others

[0213] In the above embodiment, an example is shown where the access point (AP) sends data to the terminal 20. However, the terminal 20 can send data to the access point (AP) even when there are multiple links. When the status of multiple links changes, the link management units 120 and 220 update the link management information 121 and 221, respectively. The link management units 120 and 220 can update the association between traffic and STA functions according to the increase or decrease in the number of links.

[0214] In the above embodiments, an example is shown where terminal 20 requests the creation of multiple links from base station 10 during multi-link processing, but this is not a limitation. For example, base station 10 may request the creation of multiple links from terminal 20 based on the fact that multiple links have been created between base station 10 and terminal 20.

[0215] In the above embodiments, an example is shown where the primary link and secondary link are set to active mode after multi-link processing, but this is not a limitation. When creating multiple links, it is sufficient that at least the primary link is set to active mode, while the secondary link can be set to either active mode or action pause mode. The secondary link can switch between action pause mode and active mode based on specified conditions.

[0216] In the above embodiments, the example shown is the creation of multiple links using STA functions in different frequency bands, but it is not limited to this. Multiple links can be created between base station 10 and terminal 20 using multiple channels (CH) included in the same frequency band. For example, multiple STA functions can form multiple links using different channels in the 5GHz frequency band. In this case, the primary change processing described in the first and second embodiments, and the channel change processing described in the third embodiment, can also be performed.

[0217] The structure of the wireless system 1 described in this embodiment is merely an example, and other structures are also possible. For example, the example shown illustrates a case where both base station 10 and terminal 20 have three STA functions (wireless signal processing units), but it is not limited to this. It is sufficient that base station 10 has at least two wireless signal processing units. Similarly, it is sufficient that terminal 20 has at least two wireless signal processing units. Furthermore, the number of channels that each STA function can handle can be appropriately set according to the frequency band used. Wireless communication components 14 and 24 can each utilize multiple communication components to handle wireless communication across multiple frequency bands, or they can utilize a single communication component to handle wireless communication across multiple frequency bands.

[0218] Furthermore, the functional structures of the base station 10 and terminal 20 in the wireless system 1 described in this embodiment are merely one example. The functional structures of the base station 10 and terminal 20 can be named and grouped in any way that enables them to perform the operations described in each embodiment. For example, in the base station 10, the data processing unit 110 and the link management unit 120 can be collectively referred to as the data processing unit. Similarly, in the terminal 20, the data processing unit 210 and the link management unit 220 can be collectively referred to as the data processing unit.

[0219] Furthermore, in the wireless system 1 described in the embodiments, the CPUs included in the base station 10 and the terminal 20 can be other circuits. For example, an MPU (Micro Processing Unit) can be used instead of a CPU. Additionally, the processes described in each embodiment can be implemented by dedicated hardware. The wireless system 1 described in each embodiment may contain a mixture of software-executed processes and hardware-executed processes, or only one of them may exist.

[0220] In each embodiment, the flowchart illustrating the actions is merely an example. The order of processing for each action described in the embodiments can be rearranged to the extent possible, and other processes can be added. Furthermore, the format of the wireless frame described in the above embodiments is merely an example. The wireless system 1 can use other wireless frame formats as long as it is able to perform the actions described in each embodiment.

[0221] 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 spirit. Additionally, the embodiments can be appropriately combined, in which case combined effects can be obtained. Moreover, the above embodiments include various inventions, and various inventions can be derived by selecting and combining from multiple disclosed technical features. For example, deleting several technical features from all the technical features shown in the embodiments can also solve the problem; if an effect is obtained, the structure with the deleted technical feature can also be derived as an invention.

[0222] Explanation of the label

[0223] 1… Wireless System

[0224] 10…base stations

[0225] 20…terminal

[0226] 30… servers

[0227] 11, 21... CPU

[0228] 12, 22…ROM

[0229] 13, 23…RAM

[0230] 14, 24… wireless communication components

[0231] 15…Wired communication components

[0232] 25… monitor

[0233] 26… storage

[0234] 110, 210… Data Processing Department

[0235] 120, 220… Link Management Department

[0236] 121, 221… Link Management Information

[0237] 122, 222…

[0238] 123, 223…

[0239] 124…Data Classification Department

[0240] 125…Send queue

[0241] 126…CSMA / CA Implementation Department

[0242] 127…Data Conflict Management Department

[0243] 130, 140, 150, 230, 240, 250… Wireless Signal Processing Department

Claims

1. A base station that communicates with a terminal based on the IEEE 802.11 standard. The base station has: A first wireless signal processing unit, which establishes a first link with the terminal; A second wireless signal processing unit, which establishes a second link with the terminal that is different from the first link; and The link management unit uses the first link and the second link to create multiple links with the terminal. When the link management unit is in a first state where it communicates using only the first link by setting the first link to an active state and setting the second link to a passive state, the link management unit changes from the first state to a second state where it communicates using only the second link by setting the second link to an active state and setting the first link to a passive state.

2. A terminal that communicates with a base station based on the IEEE 802.11 standard. The terminal has: have: The first wireless signal processing unit establishes a first link with the base station; A second wireless signal processing unit, which establishes a second link with the base station that is different from the first link; and The link management unit creates multiple links with the base station using the first link and the second link. When the link management unit is in a first state where it communicates using only the first link by setting the first link to an active state and setting the second link to a passive state, the link management unit changes from the first state to a second state where it communicates using only the second link by setting the second link to an active state and setting the first link to a passive state.

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