Base stations and terminals

Abstract

To provide a base station and a terminal, which restrain power consumption of a radio terminal.SOLUTION: In a radio system, a base station includes first and second radio signal processing parts, each of which transmits / receives radio signals by using first and second channels, respectively, and establishes a multi-link with a terminal by using the first and second radio signal processing parts. The first and second radio signal processing parts respectively store first and second time information, and the first time information and the second time information are synchronized with each other. The first and second radio signal processing parts respectively accumulate first and second traffic. The first radio signal processing part transmits a beacon signal indicating the first time information, information indicating that the first traffic has been accumulated, and information indicating that the second traffic has been accumulated. The second radio signal processing part receives a frame requesting transmission of the second traffic from the terminal based on the beacon signal, and transmits the second traffic to the terminal based on the received frame.SELECTED DRAWING: Figure 11

Description

Technical Field

[0001] Embodiments relate to a base station and a terminal.

Background Art

[0002] A wireless LAN (Local Area Network) is known as a wireless system that wirelessly connects between a base station and a terminal.

Prior Art Literature

Non-Patent Literature

[0003]

Non-Patent Literature 1

Summary of Invention

Problem to be Solved by the Invention

[0004] The problem is to reduce power consumption of a wireless terminal.

Means for Solving the Problem

[0005] The base station of the embodiment includes a first radio signal processing unit and a second radio signal processing unit. The first radio signal processing unit is configured to transmit and receive radio signals using a first channel. The second radio signal processing unit is configured to transmit and receive radio signals using a second channel different from the first channel. A multilink is established with a terminal using the first radio signal processing unit and the second radio signal processing unit. The first radio signal processing unit holds first time information, and the second radio signal processing unit holds second time information. The first time information and the second time information are synchronized. The first radio signal processing unit stores first traffic, and the second radio signal processing unit stores second traffic. The first radio signal processing unit transmits a beacon signal capable of indicating first time information, information indicating that first traffic is being stored, and information indicating that second traffic is being stored. The second wireless signal processing unit receives a frame from the terminal requesting the transmission of a second traffic based on the beacon signal, and transmits the second traffic to the terminal based on the received frame. [Effects of the Invention]

[0006] The base station of this embodiment can suppress the power consumption of wireless terminals. [Brief explanation of the drawing]

[0007] [Figure 1] Figure 1 is a conceptual diagram showing an example of the overall configuration of a wireless system according to the embodiment. [Figure 2] Figure 2 is a conceptual diagram showing a specific example of the wireless frame format in the wireless system according to the embodiment. [Figure 3] Figure 3 is a block diagram showing an example of the configuration of a base station included in the wireless system according to the embodiment. [Figure 4] Figure 4 is a block diagram showing an example of the functions of a base station equipped with the wireless system according to the embodiment. [Figure 5] Figure 5 is a block diagram showing an example of the configuration of a terminal in a wireless system according to an embodiment. [Figure 6]Figure 6 is a block diagram showing an example of the functions of a terminal in the wireless system according to the embodiment. [Figure 7] Figure 7 is a block diagram showing an example of a detailed function of the link management unit of a base station equipped with the wireless system according to this embodiment. [Figure 8] Figure 8 is a table showing an example of link management information in a wireless system according to this embodiment. [Figure 9] Figure 9 is a flowchart showing an example of a data transmission method during multilink operation in a wireless system according to this embodiment. [Figure 10] Figure 10 is a flowchart showing an example of a time synchronization method in a wireless system according to the embodiment. [Figure 11] Figure 11 is a conceptual diagram showing an example of a method for outputting a beacon signal at a base station of a wireless system according to an embodiment. [Figure 12] Figure 12 is a table showing an example of link management information in a wireless system according to the embodiment. [Figure 13] Figure 13 is a flowchart showing an example of a buffer notification method at a base station of a wireless system according to the embodiment. [Figure 14] Figure 14 is a conceptual diagram showing an example of a method for outputting a beacon signal at a base station of a wireless system according to the embodiment. [Figure 15] Figure 15 is a conceptual diagram showing a specific example of a beacon signal including TIM in a wireless system according to the embodiment. [Figure 16] Figure 16 is a flowchart showing an example of how to initiate multilink power saving in a wireless system according to an embodiment. [Figure 17] Figure 17 is a flowchart showing an example of a method for terminating multilink power saving in a wireless system according to an embodiment. [Figure 18] Figure 18 is a flowchart showing an example of a communication method during multilink power saving in a wireless system according to this embodiment. [Figure 19]FIG. 19 is a flowchart illustrating an example of a communication method during multi-link power save in a wireless system according to an embodiment. [Figure 20] FIG. 20 is a block diagram illustrating an example of functions of a base station included in a wireless system according to a first modification of the embodiment. [Figure 21] FIG. 21 is a block diagram illustrating an example of functions of a terminal included in a wireless system according to the first modification of the embodiment. [Figure 22] FIG. 22 is a table illustrating an example of link management information in a wireless system according to a second modification of the embodiment. [Figure 23] FIG. 23 is a conceptual diagram illustrating an example of a beacon signal output method in a base station included in a wireless system according to the second modification of the embodiment. [Figure 24] FIG. 24 is a conceptual diagram illustrating an example of frequency bands used for wireless communication in a wireless system according to a third modification of the embodiment. [Figure 25] FIG. 25 is a table illustrating an example of link management information in a wireless system according to the third modification of the embodiment. DESCRIPTION OF EMBODIMENTS

[0008] Hereinafter, a wireless system 1 according to an embodiment will be described with reference to the drawings. The embodiments exemplify apparatuses and methods for embodying the technical idea of the present invention. The drawings are schematic or conceptual. Dimensions, ratios, and the like in each drawing are not necessarily the same as actual ones. The technical idea of the present invention is not limited by the shapes, structures, arrangements, and the like of constituent elements. In the following description, constituent elements having substantially the same functions and configurations are denoted by the same reference numerals.

[0009] <1> Configuration of Wireless System 1 <1-1> Overall Configuration of Wireless System 1 FIG. 1 illustrates an example of a configuration of a wireless system 1 according to an embodiment. As illustrated in FIG. 1, the wireless system 1 includes, for example, a base station 10, a terminal 20, and a server 30.

[0010] Base station 10 is connected to a network NW and used as a wireless LAN access point. For example, base station 10 can wirelessly distribute data received from the network NW to terminal 20. Base station 10 can also connect to terminal 20 using one or more types of bandwidths. In this specification, a wireless connection between base station 10 and terminal 20 using multiple types of bandwidths is referred to as "multilink". Communication between base station 10 and terminal 20 is based on, for example, the IEEE 802.11 standard.

[0011] Terminal 20 is, for example, a wireless terminal such as a smartphone or tablet PC. Terminal 20 can send and receive data to and from a server 30 on the network NW via a wirelessly connected base station 10. Terminal 20 may also be other electronic devices such as a desktop computer or laptop computer. Terminal 20 only needs to be a device that can communicate with at least the base station 10 and can perform the operations described later.

[0012] Server 30 is capable of holding various types of information, for example, it holds content data targeted to terminal 20. Server 30 is configured to be connected to a network NW via a wired connection and to be able to communicate with base station 10 via the network NW. It is sufficient that server 30 can communicate with at least base station 10. In other words, communication between base station 10 and server 30 may be wired or wireless.

[0013] In the wireless system 1 according to this embodiment, 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, communication functions are divided into seven layers (Layer 1: Physical Layer, Layer 2: Data Link Layer, Layer 3: Network Layer, Layer 4: Transport Layer, Layer 5: Session Layer, Layer 6: Presentation Layer, Layer 7: Application Layer).

[0014] The data link layer includes, for example, the LLC (Logical Link Control) layer and the MAC (Media Access Control) layer. The LLC layer adds headers such as DSAP (Destination Service Access Point) and SSAP (Source Service Access Point) to data input from a higher-level application to form an LLC packet. The MAC layer adds a MAC header to the LLC packet to form a MAC frame.

[0015] Figure 2 shows a specific example of the format of a wireless frame used for communication between a base station 10 and a terminal 20 in a wireless system 1 according to an embodiment. As shown in Figure 2, the wireless frame includes, for example, a Frame Control field, a Duration field, an Address1 field, an Address2 field, an Address3 field, a Sequence Control field, other control information fields, a Frame Body field, and an FCS (Frame Check Sequence) field.

[0016] The Frame Control field and other control information fields correspond to, for example, the MAC header included in the MAC frame. The Frame Body field corresponds to, for example, the MAC payload included in the MAC frame. The FCS field stores the error detection code between the MAC header and the Frame Body field and is used to determine whether or not there is an error in the wireless frame.

[0017] The Frame Control field displays various control information, including, for example, the Type value, Subtype value, To DS (To Distribution System) value, and From DS value. The Type value indicates the frame type of the wireless frame. For example, a Type value of "00" indicates that the wireless frame is a management frame. A Type value of "01" indicates that the wireless frame is a control frame. A Type value of "10" indicates that the wireless frame is a data frame.

[0018] The content of a wireless frame changes depending on the combination of Type and Subtype values. For example, "00 / 1000 (Type value / Subtype value)" indicates that the wireless frame is a beacon signal. The meaning of the To DS value and From DS value differs depending on their combination. For example, "00 (To DS / From DS)" indicates that the data is between terminals within the same IBSS (Independent Basic Service Set). "10" indicates that the data frame is directed from an external source to the DS (Distribution System). "01" indicates that the data frame is destined to go outside the DS. "11" is used when configuring a mesh network.

[0019] The Duration field indicates the planned duration of use of the wireless connection. Multiple Address fields indicate the BSSID, source address, destination address, sender terminal address, receiver terminal address, etc. The Sequence Control field indicates the sequence number of the MAC frame and the fragment number for fragments. Other control information fields include, for example, Traffic Type (TID) information. TID information may be inserted at other locations within the wireless frame. The Frame Body field contains information specific to the frame type. For example, the Frame Body field stores data when it corresponds to a data frame.

[0020] <1-2> Configuration of base station 10 Figure 3 shows an example of the configuration of a base station 10 included in the wireless system 1 according to the embodiment. As shown in Figure 3, the base station 10 includes, for example, a CPU (Central Processing Unit) 11, ROM (Read Only Memory) 12, RAM (Random Access Memory) 13, a wireless communication module 14, and a wired communication module 15.

[0021] The CPU 11 is a circuit capable of executing various programs and controls the overall operation of the base station 10. The ROM 12 is a non-volatile semiconductor memory that holds programs and control data for controlling the base station 10. The RAM 13 is, for example, a volatile semiconductor memory and is used as a workspace for the CPU 11. The wireless communication module 14 is a circuit used for transmitting and receiving data via wireless signals and is connected to an antenna. The wireless communication module 14 also includes, for example, multiple communication modules corresponding to multiple frequency bands. The wired communication module 15 is a circuit used for transmitting and receiving data via wired signals and is connected to a network NW.

[0022] Figure 4 shows an example of the functional configuration of a base station 10 in a wireless system 1 according to an embodiment. As shown in Figure 4, the 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 realized, for example, by a CPU 11 and a wireless communication module 14.

[0023] The data processing unit 110 can perform LLC layer processing and higher layer (layers 3 to 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. Also, the data processing unit 110 transmits data input from the link management unit 120 to the server 30 via the network NW.

[0024] The link management unit 120 performs a portion of the MAC layer processing on the input data. The link management unit 120 also manages the link with the terminal 20 based on notifications from the radio signal processing units 130, 140, and 150. The link management unit 120 holds link management information 121 and shared time information 122. The link management information 121 is stored, for example, in RAM 13 and includes information about the terminal 20 that is wirelessly connected to the base station 10. The shared time information 122 holds time information shared within the base station 10 and can be referenced by the radio signal processing units 130, 140, and 150, respectively. The shared time information 122 corresponds to time information for synchronizing the multilink.

[0025] Each of the wireless signal processing units 130, 140, and 150 transmits and receives data between the base station 10 and the terminal 20 using wireless communication. For example, each of the wireless signal processing units 130, 140, and 150 adds a preamble, PHY header, etc., to the data input from the link management unit 120 to create a wireless frame. Then, each of the wireless signal processing units 130, 140, and 150 converts the wireless frame into a wireless signal and distributes the wireless signal via the base station 10's antenna. Also, each of the wireless signal processing units 130, 140, and 150 converts the wireless signal received via the base station 10's antenna into a wireless frame. Then, each of the wireless signal processing units 130, 140, and 150 outputs the data contained in the wireless frame to the link management unit 120.

[0026] Thus, each of the wireless signal processing units 130, 140, and 150 can perform, for example, part of the MAC layer processing and the first layer processing on the input data or wireless signal. For example, the wireless signal processing unit 130 handles wireless signals in the 2.4 GHz band. The wireless signal processing unit 140 handles wireless signals in the 5 GHz band. The wireless signal processing unit 150 handles wireless signals in the 6 GHz band. The wireless signal processing units 130, 140, and 150 may or may not share the antenna of the base station 10.

[0027] Furthermore, the wireless signal processing unit 130 holds time information 131. Time information 131 is used as the reference time for communication using the wireless signal processing unit 130. The wireless signal processing unit 140 holds time information 141. Time information 141 is used as the reference time for communication using the wireless signal processing unit 140. The wireless signal processing unit 150 holds time information 151. Time information 151 is used as the reference time for communication using the wireless signal processing unit 150. The link management unit 120 appropriately synchronizes the shared time information 122 with time information 131, 141, and 151, respectively.

[0028] <1-3>Regarding the configuration of terminal 20 Figure 5 shows an example of the configuration of a terminal 20 included in the wireless system 1 according to this embodiment. As shown in Figure 5, the terminal 20 includes, for example, a CPU 21, ROM 22, RAM 23, a wireless communication module 24, a display 25, and storage 26.

[0029] The CPU 21 is a circuit capable of executing various programs and controls the overall operation of the terminal 20. The ROM 22 is a non-volatile semiconductor memory that holds programs and control data for controlling the terminal 20. The RAM 23 is, for example, a volatile semiconductor memory and is used as the working area for the CPU 21. The wireless communication module 24 is a circuit used for sending and receiving data via wireless signals and is connected to an antenna. The wireless communication module 24 also includes, for example, multiple communication modules corresponding to multiple frequency bands. The display 25 displays, for example, a GUI (Graphical User Interface) corresponding to application software. The display 25 may also function as an input interface for the terminal 20. The storage 26 is a non-volatile storage device that holds, for example, the system software of the terminal 20. Note that the terminal 20 does not necessarily have a display. For example, in an IoT terminal, the display 25 may be omitted.

[0030] Figure 6 shows an example of the functional configuration of a terminal 20 in a wireless system 1 according to an embodiment. As shown in Figure 6, the 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 realized, for example, by a CPU 21 and a wireless communication module 24.

[0031] The data processing unit 210 can perform processing at the LLC layer and processing at higher layers (layers 3 to 7) 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. Also, the data processing unit 210 outputs data input from the link management unit 220 to the application execution unit 260.

[0032] The link management unit 220 can perform some of the MAC layer processing on the input data. The link management unit 220 also manages the link with the base station 10 based on notifications from the radio signal processing units 230, 240, and 250. The link management unit 220 includes link management information 221 and shared time information 222. The link management information 221 is stored, for example, in RAM 23 and includes information about the base station 10 to which the terminal 20 is connected. The shared time information 222 contains time information shared within the terminal 20 and can be referenced by the radio signal processing units 230, 240, and 250, respectively. The shared time information 222 corresponds to time information for synchronizing the multilink.

[0033] Each of the wireless signal processing units 230, 240, and 250 transmits and receives data between the base station 10 and the terminal 20 using wireless communication. For example, each of the wireless signal processing units 230, 240, and 250 adds a preamble, PHY header, etc., to the data input from the link management unit 220 to create a wireless frame. Then, each of the wireless signal processing units 230, 240, and 250 converts the wireless frame into a wireless signal and distributes the wireless signal via the antenna of the terminal 20. In addition, each of the wireless signal processing units 230, 240, and 250 converts the wireless signal received via the antenna of the terminal 20 into a wireless frame. Then, each of the wireless signal processing units 230, 240, and 250 outputs the data contained in the wireless frame to the link management unit 220.

[0034] Thus, each of the wireless signal processing units 230, 240, and 250 can perform, for example, part of the MAC layer processing and the first layer processing on the input data or wireless signal. For example, the wireless signal processing unit 230 handles wireless signals in the 2.4 GHz band. The wireless signal processing unit 240 handles wireless signals in the 5 GHz band. The wireless signal processing unit 250 handles wireless signals in the 6 GHz band. The wireless signal processing units 230, 240, and 250 may or may not share the antenna of the terminal 20.

[0035] Furthermore, the wireless signal processing unit 230 holds time information 231. Time information 231 is used as the reference time for communication using the wireless signal processing unit 230. The wireless signal processing unit 240 holds time information 241. Time information 241 is used as the reference time for communication using the wireless signal processing unit 240. The wireless signal processing unit 250 holds time information 251. Time information 251 is used as the reference time for communication using the wireless signal processing unit 250. The link management unit 220 appropriately synchronizes the shared time information 222 with time information 231, 241, and 251, respectively.

[0036] The application execution unit 260 executes an application that can utilize the 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 operate based on the operation of the input interface.

[0037] In the wireless system 1 according to the embodiment described above, the wireless signal processing units 130, 140, and 150 of the base station 10 are configured to be connectable to the wireless signal processing units 230, 240, and 250 of the terminal 20, respectively. That is, wireless connection between wireless signal processing units 130 and 230 can be made using the 2.4GHz band. Wireless connection between wireless signal processing units 140 and 240 can be made using the 5GHz band. Wireless connection between wireless signal processing units 150 and 250 can be made using the 6GHz band. In this specification, each wireless signal processing unit may be referred to as an "STA function". That is, the wireless system 1 according to the embodiment has multiple STA functions.

[0038] <1-4> Detailed structure of the Link Management Department Figure 7 shows details of the channel access function in the link management unit 120 of the base station 10 of the wireless system 1 according to the embodiment. Note that the function of the link management unit 220 of the terminal 20 is the same as that of the link management unit 120 of the base station 10, for example, so its description is omitted. As shown in Figure 7, the link management unit 120 includes, for example, a data categorization unit 123, transmission queues 124A, 124B, 124C, 124D and 124E, CSMA / CA (Carrier Sense Multiple Access with Collision Avoidance) execution units 125A, 125B, 125C, 125D and 125E, and a data collision management unit 126.

[0039] The data categorization unit 123 categorizes the data input from the data processing unit 110. Examples of data categories include "LL (Low Latency)", "VO (Voice)", "VI (Video)", "BE (Best Effort)", and "BK (Background)". LL is applied to data requiring low latency. Therefore, it is preferable that LL data be processed with priority over any of the VO, VI, BE, and BK data.

[0040] The data categorization unit 123 then inputs the categorized data into one of the transmission queues 124A, 124B, 124C, 124D, and 124E. Specifically, LL data is input into transmission queue 124A, VO data into transmission queue 124B, VI data into transmission queue 124C, BE data into transmission queue 124D, and BK data into transmission queue 124E. The data of each category that is input is then stored in the corresponding transmission queue 124A through E.

[0041] Each of the CSMA / CA execution units 125A, 125B, 125C, 125D, and 125E waits for a time specified by pre-configured access parameters, while confirming through carrier sensing that no other terminals are transmitting wireless signals in CSMA / CA. Then, each of the CSMA / CA execution units 125A, 125B, 125C, 125D, and 125E retrieves data from the transmission queues 124A, 124B, 124C, 124D, and 124E, respectively, and outputs the retrieved data to at least one of the wireless signal processing units 130, 140, and 150 via the data collision management unit 126. The wireless signal containing this data is then transmitted by the wireless signal processing unit (STA function) for which transmission rights have been acquired by CSMA / CA.

[0042] The CSMA / CA execution unit 125A performs CSMA / CA on the LL data held in the transmission queue 124A. The CSMA / CA execution unit 125B performs CSMA / CA on the VO data held in the transmission queue 124B. The CSMA / CA execution unit 125C performs CSMA / CA on the VI data held in the transmission queue 124C. The CSMA / CA execution unit 125D performs CSMA / CA on the BE data held in the transmission queue 124D. The CSMA / CA execution unit 125D performs CSMA / CA on the BK data held in the transmission queue 124E.

[0043] Access parameters are assigned in the order of priority for radio signal transmission, for example, 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 is the transmission waiting time to avoid conflicts. AIFS (Arbitration Inter Frame Space) represents a fixed transmission 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, for transmission queue 124, the shorter the CWmin and CWmax, the easier it is to obtain transmission rights. The priority of transmission queue 124 is higher as the AIFS is smaller. The amount of data transmitted in a single transmission right is greater as the value of TXOPLimit is larger.

[0044] The data collision management unit 126 prevents data collisions when multiple CSMA / CA execution units 125 acquire transmission rights for the same STA function. Specifically, the data collision management unit 126 adjusts the transmission timing of data from different categories that have acquired transmission rights for the same STA function, and transmits data from the category with higher priority to the STA function first. For example, an STA function that has acquired transmission rights through CSMA / CA in transmission queue 124A of LL may be the same as an STA function that has acquired transmission rights through CSMA / CA in any of the other transmission queues 124B to 124E. In this case, the data collision management unit 126 prioritizes transmitting the data stored in transmission queue 124A to the STA function. Similarly, in other combinations of transmission queues 124, data is transmitted in an order based on the priority set for each category. This prevents collisions between data that have been assigned to transmit to the same STA function.

[0045] This embodiment describes a configuration in which the link management unit implements the channel access function, but each STA function may also implement the channel access function. When the link management unit implements the channel access function, each STA function detects the state of the radio channel (idle / busy) on the corresponding link, and the link management unit determines whether or not to transmit data (which link to use for transmission, etc.). On the other hand, when each STA function implements the channel access function, each STA function can independently perform carrier sensing and transmit data. In this case, channel access when multiple links are used simultaneously may be performed by commonizing access parameters through communication between multiple STA functions, or by commonizing access parameters by the link management unit. The base station 10 and terminal 20 can use multiple links simultaneously by transmitting data between multiple STA functions based on common access parameters.

[0046] <2> Operation of Wireless System 1 In the wireless system 1 according to this embodiment, a multilink between the base station 10 and the terminal 20 can be established in response to a request from either the base station 10 or the terminal 20. Below is an example of the operation when the base station 10 and the terminal 20 have established a multilink in the wireless system 1 according to this embodiment.

[0047] Figure 8 shows an example of link management information 121 in the wireless system 1 according to the embodiment. Note that the link management information 221 of the terminal 20 contains similar information to the link management information 121 of the base station 10, so its explanation is omitted. As shown in Figure 8, the link management information 121 includes information such as STA function, frequency band, operating mode, link destination ID, presence or absence of multilink, and TID.

[0048] In this example, “STA1” corresponds to the STA function using the 6GHz frequency band, i.e., the wireless signal processing unit 150 or 250. “STA2” corresponds to the STA function using the 5GHz frequency band, i.e., the wireless signal processing unit 140 or 240. “STA3” corresponds to the STA function using the 2.4GHz frequency band, i.e., the wireless signal processing unit 130 or 230.

[0049] The operating mode indicates the current operating mode of the STA function. Examples of STA function operating modes include active mode, intermittent operation mode, and operation pause mode. Active mode corresponds to a state in which the terminal 20's STA function maintains the Awake state, allowing for continuous transmission and reception of wireless signals. Intermittent operation mode corresponds to a state in which the terminal 20's STA function alternates between the Awake and Doze states, resulting in intermittent operation. Operation pause mode corresponds to a state in which the terminal 20's STA function maintains the Doze state, making transmission and reception of wireless signals impossible. Multiple STA functions constituting a multilink include at least one link in active mode or intermittent operation mode. Other links constituting the multilink may be set to active mode, intermittent operation mode, or operation pause mode.

[0050] The Awake state corresponds to a state in which wireless signals can be sent and received. The Dose state corresponds to a state in which wireless signals cannot be sent or received. In the Doze state, the power supply to the circuit related to 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. Although the base station 10 or terminal 20 can use it for communication, there may be links that are not included in the multilink link set between them (Disabled links, corresponding to "Off" in Figure 8). In the following explanation, for the sake of brevity, links in Active mode or Intermittent operation mode, i.e., links that can communicate, will be referred to as the "Awake state STA function." Links in Operation pause mode, i.e., links in a power-saving state in which communication is not possible, will be referred to as the "Dose state STA function."

[0051] The link destination ID corresponds, for example, 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, a multilink is established using STA1 and STA2. When a multilink is established, each of the link management units 120 and 220 transmits the data input from the upper layer using the link of at least one STA function associated with the multilink.

[0052] The “TID” in the link management information 121 indicates the association between an STA function and TID information. Each STA function sends and receives data corresponding to the assigned TID information. Each of TID#1 to 3 corresponds to one of LL, VO, VI, BE, or BK. One STA function may be associated with one traffic, i.e., one TID, or multiple STA functions may be associated with it. In this example, TID#1 is assigned to both STA1 and STA2. TID#2 is assigned to STA1. TID#3 is assigned to STA2.

[0053] Traffic flows corresponding to such associations between traffic and STA functions are pre-configured during the setup of the multilink between the base station 10 and the terminal 20. For example, the link management unit 220 of the terminal 20 determines the association between traffic and STA functions and requests it from the link management unit 120 of the base station 10. The base station 10 then responds to the request, thereby confirming the association between traffic and STA functions.

[0054] The traffic described above is, for example, set to be evenly distributed across the multiple links that make up a multilink. However, it is not limited to this, and similar types of traffic (e.g., priority / non-priority) may be grouped together on one of the links that make up the multilink. Furthermore, as for the association between STA functions and traffic, for example, audio may be associated with the 2.4GHz frequency band, and video with 5G. In this way, it is preferable that the frequencies used for transmission and reception are allocated according to the type of information and data capacity being handled.

[0055] The following describes, in order, the various operations that occur when the base station 10 and the terminal 20 establish a multilink, focusing on each of the base station 10 and the terminal 20.

[0056] <2-1> Operation of base station 10 (Regarding data transmission methods when using multilink) Figure 9 shows an example of a data transmission method in multilink mode at a base station 10 of the wireless system 1 according to the embodiment. As shown in Figure 9, when the base station 10 obtains data from the upper layer, it sequentially executes the processes in steps S10 to S12.

[0057] Specifically, in step S10, the link management unit 120 first obtains the TID information corresponding to the data. In other words, the link management unit 120 refers to the MAC header in the wireless frame obtained from the upper layer, for example, and checks whether the TID information contained in the MAC header is LL, VO, VI, BE, or BK. This allows the link management unit 120 to determine which TID corresponds to the traffic flow of the data.

[0058] Next, in step S11, 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. Note that the number of STA functions acquired by the link management unit 120 in step S11 may be one or multiple.

[0059] Next, in step S12, the link management unit 120 outputs data to the acquired STA function. If one STA function is associated with the output data (traffic), the data is transmitted serially using that one STA function. On the other hand, if multiple STA functions are associated with the traffic, the data is transmitted in parallel using multiple STA functions.

[0060] Furthermore, when a single traffic is transmitted in parallel, data distribution and reordering are performed between the link management unit 120 of the base station 10 and the link management unit 220 of the terminal 20. Data distribution is performed by the link management unit on the transmitting side, and data reordering 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 that it is a multilink and an identification number to the radio frame. The link management unit on the receiving side reorders the data based on the added flag and identification number.

[0061] Furthermore, in the wireless system 1 according to this embodiment, the link management unit may perform aggregation by combining multiple data received from a higher layer. Aggregation in multilink may be used as an optional function that can be selected by the user.

[0062] (Regarding time synchronization methods) In the wireless system 1 according to this embodiment, time synchronization within the BSS (Basic Service Set) is necessary in order to perform CSMA / CA, etc. Therefore, the base station 10 appropriately transmits beacon signals to synchronize time with the terminal 20 that forms the link. The following describes an example in which the base station 10 transmits a beacon signal containing time information when each STA function of the terminal 20 on which a multilink has been established is in the Awake state.

[0063] Figure 10 shows an example of a time synchronization method in a base station 10 of the wireless system 1 according to this embodiment. As shown in Figure 10, the base station 10 sequentially executes steps S20 to S22 in order to synchronize the time within the BSS.

[0064] Specifically, in step S20, the time information of each STA function constituting the multilink is synchronized with the shared time information 122. In other words, the link management unit 120 transmits the shared time information 122 to each STA function (wireless signal processing units 130, 140, and 150). The shared time information 122 then overwrites the time information 131 in the wireless signal processing unit 130, the time information 141 in the wireless signal processing unit 140, and the time information 151 in the wireless signal processing unit 150.

[0065] Next, in step S21, each STA function constituting the multilink creates a beacon signal containing the same time information. Specifically, the radio signal processing units 130, 140, and 150 each create beacon signals containing time information 131, 141, and 151. These time information units 131, 141, and 151 contain the same time information as a result of the processing in step S20. Alternatively, the link management unit 120 may create a beacon signal containing the same time information and provide the created beacon signal to each STA function.

[0066] Next, in step S22, each STA function constituting the multilink simultaneously transmits a beacon signal. Each STA function can transmit a beacon signal when, for example, it is in the Awake state of the active mode or the Awake state of the intermittent operation mode. On the other hand, each STA function cannot transmit a beacon signal when it is in the Disable state or the Doze state of the intermittent operation mode. In this embodiment, a form is described in which beacon signals containing the same time information are transmitted simultaneously from each STA function, but this is not limited to this. For example, beacon signals containing time information shared by each STA function may be transmitted at different times. In other words, it is sufficient that the time information handled among the multiple STA functions constituting the multilink is synchronized, and the time information of the beacon signal is generated based on said synchronized time information.

[0067] As described above, the beacon signal containing time information transmitted by the base station 10 can be received by the terminal 20. The terminal 20 uses the STA function in the Awake state to receive the beacon signal. The link management unit 220 of the terminal 20 then overwrites the shared time information 222 with the time information contained in the received beacon signal. In other words, the time information contained in the beacon signal and the shared time information 222 of the terminal 20 are synchronized. Similarly, the time information of the STA function used to receive the beacon signal is also synchronized with the time information contained in the beacon signal. If it is necessary to compensate for the time information offset due to the physical distance between the base station 10 and the terminal 20, the STA function in the Awake state of the terminal 20 performs Fine Timing Management and overwrites the shared time information with the time information of the received beacon signal, taking the offset into account. As a result, the STA function that has transitioned from the Doze state to the Awake state can use the time information with the offset taken into account by using the shared time information. Here, Fine Timing Management refers to high-precision timing management as defined in IEEE 802.11-2016. By incorporating the offset provided by Fine Timing Management, the STA function can transition to the Awake state and quickly achieve high-precision synchronization even if terminal 20 moves while in the Doze state.

[0068] Furthermore, since a multilink includes at least one STA function in the Awake state, the synchronization of time information described above can be performed even if the multilink includes an STA function in the Doze state. In addition, terminal 20 may receive a beacon containing time information with multiple STA functions that constitute the multilink. In this case, the time information of the STA function that received the beacon signal is synchronized, and the shared time information 222 is updated based on the beacon signal received by any of the STA functions. The STA function used to update the shared time information 222 at this time is selected, for example, based on the priority set for each STA function.

[0069] Figure 11 shows an example of a method for outputting a beacon signal at a base station 10 of the wireless system 1 according to the embodiment, and corresponds to the operation described in Figure 10. In this example, STA1 and STA2 have established a multilink. STA1 and STA2 are set to the Awake state, and STA3 is set to the Disable state ("off").

[0070] As shown in Figure 11, STA1 and STA2, which constitute the multilink, each transmit beacon signals intermittently. On the other hand, the transmission of beacon signals by STA3, which is in a disabled state, is omitted. Furthermore, the beacon signals transmitted simultaneously by STA1 and STA2 each contain the same time information (reference time information). Specifically, the time information 131 contained in the beacon signal transmitted by STA1 and the time information 141 contained in the beacon signal transmitted by STA2 contain the same time information synchronized with the shared time information 122.

[0071] (Regarding how to notify about buffer status) In this embodiment, the base station 10 appropriately transmits a beacon signal to the terminal 20 to notify the data buffer status when the multilink includes a link in dormant mode (STA function in Dose state). Figure 12 shows an example of link management information 121 in the wireless system 1 according to this embodiment. The link management information 121 shown in Figure 12 includes information that the operating mode of STA1 has been changed to intermittent operation mode (Awake state) and the operating mode of STA2 has been changed to dormant mode (Doze state) compared to the link management information 121 shown in Figure 8. Below, an example of the base station 10 constituting the multilink shown in Figure 12 transmitting a beacon signal regarding buffer status notification will be described.

[0072] Figure 13 shows an example of a method for notifying the buffer status at a base station 10 of the wireless system 1 according to the embodiment. As shown in Figure 13, the base station 10 sequentially executes the processes in steps S30 to S32 in order to notify the terminal 20 of the buffer status.

[0073] Specifically, in step S30, the link management unit 120 first checks the data buffer status corresponding to the STA function that constitutes the multilink. In other words, the link management unit 120 checks whether data has been accumulated in the multiple transmission queues 124 corresponding to, for example, TID#1 to 3.

[0074] Next, in step S31, a beacon signal including a TIM (Traffic Indication Map) is created based on the data buffer status. The TIM is an information element for notifying terminal 20, which is in power-saving mode, of incoming data. The creation of this beacon signal may be performed by the link management unit 120 or by each STA function. Specific examples of the format of the beacon signal including the TIM will be described later.

[0075] Next, in step S32, the base station 10 transmits a beacon signal using an STA function that has configured a multilink and is in the Awake state. In other words, if the multilink includes an STA function in the Doze state, the base station 10 transmits the beacon signal created in step S31 using at least one STA function that is in the Awake state among the STA functions that have established the multilink. In this example, the base station 10 uses STA1 to transmit the beacon signal.

[0076] Figure 14 shows an example of the beacon signal output method at the base station 10 of the wireless system 1 according to the embodiment, and corresponds to the operation described in Figure 13. In this example, STA1 and STA2 establish a multilink, and STA1 and STA2 are set to the Awake state and Doze state, respectively. STA3 is set to the Disable state.

[0077] As shown in Figure 14, of the STA1 and STA2 that make up the multilink, STA1 in the Awake state intermittently transmits beacon signals. On the other hand, the transmission of beacon signals by STA2 in the Doze state and STA3 in the Disable state is omitted.

[0078] Figure 15 shows a specific example of a beacon signal including a TIM corresponding to the multilink shown in Figure 12 in the wireless system 1 according to the embodiment. As shown in Figure 15, the beacon signal includes, for example, a terminal identifier, link identifier #1, buffer information #1, link identifier #2, and buffer information #2, in this order.

[0079] The terminal identifier includes, for example, the Association Identifier (AID) between base station 10 and terminal 20. Link identifiers #1 and #2 each contain the link identifiers of one and the other link constituting the multilink. Buffer status #1 and #2 indicate the buffer status of the traffic corresponding to link identifiers #1 and #2, respectively. For example, a buffer status of "0" indicates that no traffic has been accumulated for the associated link identifier. A buffer status of "1" indicates that traffic has been accumulated for the associated link identifier. Note that the assignment of bits indicating buffer status and whether or not traffic has been accumulated can be arbitrarily changed.

[0080] As described above, in the wireless system 1 according to the embodiment, the base station 10 can transmit a beacon signal to the terminal 20 that includes information indicating whether or not traffic is being accumulated for each link that has established a multilink. The beacon signal notifying the buffer status includes the buffer status of the STA function corresponding to the STA function forming the link, regardless of whether the STA function is in the Awake state or the Doze state.

[0081] Furthermore, the header of the beacon signal includes information indicating how many STA function buffer status information is contained in the beacon signal. If a multilink is established by three or more STA functions, the beacon signal may contain three or more pairs of link identifiers and corresponding buffer statuses. The beacon signal may or may not contain information about links that have not been established.

[0082] <2-2> Operation of Terminal 20 In this embodiment, terminal 20 applies a doze mode to some of the links constituting the multilink depending on the communication status. Below, the state of the multilink including the links in doze mode (doze state) is referred to as "multilink power save," and various examples of operations related to multilink power save by terminal 20 are described. In the following description, it is assumed that a multilink using STA1 and STA2 is established between base station 10 and terminal 20. Also, for the sake of brevity, STA1 and STA2 of base station 10 are also referred to as "access point APs." The transmission of radio signals from terminal 20's STA1 and STA2 to the access point AP corresponds to the transmission of radio signals to base station 10's STA1 and STA2, respectively. When STA1 and STA2 are mentioned individually, they refer to the STA functions of terminal 20.

[0083] (How to start multilink power saving) Figure 16 is a flowchart showing an example of how to initiate multilink power saving in the wireless system 1 according to this embodiment. At the start of this operation, STA1 and STA2 are both in the Awake state. As shown in Figure 16, the access point AP transmits a beacon signal to each of STA1 and STA2 of terminal 20 (step S40). This beacon signal includes information, for example, indicating that the traffic for each of STA1 and STA2 is empty, and is received by STA1 and STA2, respectively.

[0084] The STA1 of terminal 20 transmits a radio signal to the access point AP to notify it of the start of multilink power saving, for example, depending on whether the traffic is empty (step S41). The data frame of the radio signal notifying the start of multilink power saving includes a PM (Power Management) bit containing, for example, "1". Upon receiving the "PM=1" signal, the access point AP transmits a radio signal (Data ACK) to the STA1 of terminal 20 to notify it that it has received the signal (step S42).

[0085] When terminal 20's STA1 receives a Data ACK for sending a data frame containing "PM=1", terminal 20's link management unit 220 transitions, for example, STA2 from active mode or intermittent operation mode (Awake state) to operation pause mode (Doze state) (step S43). As a result, the total power consumption of STA1 and STA2 constituting the multilink becomes lower than before the use of operation pause mode. Note that in the process of step S43, it is sufficient that at least one STA function among the multiple STA functions constituting the multilink is set to the Doze state.

[0086] After sending a Data ACK for receiving "PM=1", the access point AP sends a beacon signal including TIM to terminal 20's STA1 (step S44). At this time, STA1 in the Awake state can receive the beacon signal. On the other hand, STA2 in the Doze state does not receive the beacon signal and maintains a lower power consumption state than STA1.

[0087] As described above, in the wireless system 1 according to this embodiment, terminal 20 can transition to multilink power save mode depending on the traffic state, thereby suppressing multilink power consumption. Based on the fact that terminal 20 has transitioned to multilink power save mode, base station 10 intermittently transmits a beacon signal including TIM to notify the data buffer status to the STA function of terminal 20, which is in the Awake state. Details of the communication method between base station 10 and terminal 20 during multilink power save mode will be described later.

[0088] (How to end multilink power save) Figure 17 shows an example of the procedure for terminating multilink power saving in the wireless system 1 according to the embodiment. At the start of this operation, STA1 and STA2 are in the Awake state and Doze state, respectively. As shown in Figure 17, the access point AP transmits a beacon signal to each of STA1 and STA2 of terminal 20 (step S50). This beacon signal contains information, for example, requesting terminal 20 to terminate multilink power saving, and is received by STA1 in the Awake state.

[0089] Upon receiving the beacon signal, the STA1 of terminal 20 transmits a radio signal to the access point AP notifying it of the end of multilink power saving (step S51). The data frame of the radio signal notifying it of the end of multilink power saving includes a PM bit containing, for example, "0". Upon receiving the "PM=0" signal, the access point AP transmits a radio signal (Data ACK) to the STA1 of terminal 20 notifying it that it has received the signal (step S52).

[0090] When terminal 20's STA1 receives a Data ACK for sending a data frame containing "PM=0", terminal 20's link management unit 220 transitions STA2 from doze mode to active mode or awake mode (step S53). As a result, both STA1 and STA2, which constitute the multilink, become capable of receiving radio signals from base station 10.

[0091] After sending a Data ACK for receiving "PM=0", the access point AP transmits a beacon signal to terminals 20 STA1 and STA2 respectively (step S54). This beacon signal contains various information elements necessary for communication.

[0092] As described above, the base station 10 in the wireless system 1 according to the embodiment can transition the STA function set to operation dormant mode within the multilink to active mode or intermittent operation mode as needed, and set multiple STA functions constituting the multilink to a state where they can communicate. In the above description, the example given is when an STA function in the Doze state transitions to the Awake state based on a beacon signal from the base station 10, but the description is not limited to this. The terminal 20 may transition an STA function in the Doze state to the Awake state based on user operation or application control.

[0093] (Regarding operation during multilink power saving) Figures 18 and 19 show an example of the operation flow during multilink power saving in the wireless system 1 according to the embodiment. Figure 18 corresponds to the operation when the access point AP receives data intended for STA1, which is in the Awake state. Figure 19 corresponds to the operation when the access point AP receives data intended for STA2, which is in the Doze state.

[0094] First, let's describe an example of the operation of the wireless system 1 when the access point AP receives data intended for STA1, which is in the Awake state. As shown in Figure 18, when the access point AP receives data intended for STA1 from terminal 20, it stores the data in the transmission queue 124 of the link management unit 120, for example. Then, the access point AP sends a beacon signal including a TIM indicating that the buffer status of the data intended for STA1 is "1" to the Awake state STA1 (step S60).

[0095] The beacon signal received by STA1 of terminal 20 is then forwarded to the link management unit 220. Based on the beacon signal, the link management unit 220 sends a PS-Poll (Power Save-Poll) frame to the access point AP via STA1, requesting the transmission of data for STA1 (step S61). When the access point AP receives the PS-Poll frame from STA1 of terminal 20, it sends a Data ACK containing the data stored for STA1 to STA1 of terminal 20 (step S62). As a result, STA1 of terminal 20 can receive the data stored for its own station at the access point AP.

[0096] Once the transmission of data to STA1 is complete and the data for STA1 in the transmission queue 124 is cleared, the access point AP sends a beacon signal containing a TIM indicating that the data buffer status for STA1 is "0" to STA1 on terminal 20 (step S63). In other words, the access point AP notifies the link management unit 220 of terminal 20 via STA1 that the transmission of data for STA1 is complete.

[0097] Next, an example of the operation of the wireless system 1 when the access point AP receives data intended for STA2 in the Doze state will be described. As shown in Figure 19, when the access point AP receives data intended for STA2 from terminal 20, it stores the data in the transmission queue 124 of the link management unit 120, for example. Then, the access point AP sends a beacon signal including a TIM indicating that the buffer status of the data intended for STA2 is "1" to STA1 in the Awake state (step S70).

[0098] The beacon signal received by STA1 of terminal 20 is then forwarded to the link management unit 220. The link management unit 220 then transitions STA2 from the Doze state to the Awake state based on the beacon signal (step S71). After transitioning to the Awake state, STA2 first refers to the shared time information 222 and synchronizes the time information 241 corresponding to STA2 with the shared time information 222.

[0099] Subsequently, the link management unit 220 sends a PS-Poll (Power Save-Poll) frame requesting the transmission of data for STA2 to the access point AP via STA2 (step S72). When the access point AP receives the PS-Poll frame from the terminal 20's STA2, it sends a Data ACK containing the data stored for that STA2 to the terminal 20's STA2 (step S73). As a result, the terminal 20's STA2 can receive the data stored for its own station at the access point AP.

[0100] Once the transmission of data to STA2 is complete and the data for STA2 in the transmission queue 124 is cleared, the access point AP sends a beacon signal containing a TIM indicating that the buffer status of STA2 is "0" to STA1 on terminal 20 (step S74). In other words, the access point AP notifies the link management unit 220 of terminal 20 via STA1 that the transmission of data to STA2 is complete. This beacon signal may also be received by STA2. Then, based on the beacon signal, the link management unit 220 transitions STA2 from the Awake state to the Doze state (step S75). In other words, based on the completion of data transmission, the STA functions that are not used to receive the beacon signal among the STA functions constituting the multilink are set again to the power-saving Doze state.

[0101] As described above, the base station 10 in the wireless system 1 according to the embodiment can transmit data to the terminal 20 using multilink power save. In the above description, the example given is the case where data is transmitted for each STA function, but data may be transmitted in parallel to each of the multiple STA functions that constitute the multilink. For example, when the buffer status of STA1 and STA2 is "1", the link management unit 220 of the terminal 20 may instruct STA1 and STA2 to transmit PS-Poll frames to the access point AP.

[0102] <3> Effects of the Embodiment According to the wireless system 1 of the embodiment described above, the power consumption of the terminal 20 during multilink operation can be suppressed. The effects of the wireless system 1 of the embodiment will be described in detail below.

[0103] Base stations and terminals using wireless LANs may have multiple STA functions, each provided for a specific frequency band, such as 2.4GHz, 5GHz, and 6GHz. In such wireless systems, a wireless connection is established and data communication between the base station and terminal is performed by selecting one of the multiple STA functions. In this case, the wireless system will not use any STA functions that are not selected, even if there is a base station corresponding to the frequency band of that STA function.

[0104] In contrast, the wireless system 1 according to this embodiment establishes a multilink between the base station 10 and the terminal 20 by utilizing multiple STA functions provided by each of the base station 10 and the terminal 20. Multilink data communication can use multiple bandwidths simultaneously and fully utilize the functions provided by the wireless LAN device. As a result, the wireless system 1 according to this embodiment can achieve efficient communication and improve communication speed. On the other hand, the power consumption of multilink is higher than that of singlelink because multiple STA functions are used by both the base station 10 and the terminal 20.

[0105] Therefore, the wireless system 1 according to this embodiment sets the multilink to multilink power save mode when traffic is low, etc. In multilink power save mode, for example, at least one of the multiple STA functions that constitute the multilink is set to the normal state (Awake state), and the other STA functions are set to a power-saving state (Doze state). The STA function in the Awake state can receive beacon signals from the base station 10, for example. The STA function in the Doze state is stopped, for example, in the Disable state. For this reason, the power consumption of the STA function in the Doze state is lower than that of the STA function in the Awake state.

[0106] In multilink power saving mode, an STA function in the awake state receives a beacon signal containing information corresponding to multiple STA functions that make up the multilink. For example, if data for an STA function in the doze state is input from the network NW to the base station 10, the base station 10 notifies the terminal 20 that data is being stored via the awake state STA function (link). The STA function of the terminal 20 then forwards this notification to the link management unit 220, which wakes up the STA function in the doze state. As a result, the woken STA function can acquire data from the base station 10 by transmitting a PS-Poll frame.

[0107] Furthermore, in the wireless system 1 according to this embodiment, for CSMA / CA and the like to be executed, the time information of the STA function of the base station 10 and the STA function of the terminal 20 that form the link must be synchronized. For example, when a single link is used, it is sufficient that the time synchronization between the STA function of the base station 10 and the STA function of the terminal 20 is performed for at least each link, and the time information may differ between different links.

[0108] On the other hand, when multilink is used, the STA functions that make up the multilink must be time-synchronized. In other words, multilink requires operation at different frequencies in sync. Furthermore, time synchronization within the BSS is performed by receiving beacon signals. For example, in multilink, even when multilink power saving is applied, STA functions set to active mode or intermittent operation mode (Awake state) can receive beacons and perform time synchronization.

[0109] However, in multilink power saving mode, the STA function set to the Doze state may experience a time synchronization error over time. Specifically, since the STA function in the Doze state cannot synchronize time using beacon signals, a time information discrepancy may occur depending on the accuracy of the clock referenced by the STA function. For this reason, when terminal 20 performs data transmission and reception using the STA function in the Doze state, it is preferable to wake up and then perform time synchronization of the STA function.

[0110] Therefore, in the wireless system 1 according to this embodiment, each of the base station 10 and the terminal 20 is equipped with a local clock, i.e., shared time information, that is common to all STA functions. The base station 10 then synchronously transmits a beacon signal containing the shared time information on all links that constitute a multilink, for example. When an STA function in the awakened state receives the beacon signal, it updates the shared time information if the timestamp of the beacon signal and the local clock are different.

[0111] Thus, synchronization of shared time information is performed sequentially using the STA function in the Awake state. On the other hand, the STA function in the Doze state performs time synchronization on the link using a common local clock when it wakes up. In other words, the STA function in the Doze state can perform time synchronization within the multilink after waking up without receiving a beacon signal.

[0112] As described above, in the wireless system 1 according to this embodiment, the clock for time synchronization in the multilink is common to both the base station 10 and the terminal 20. As a result, the terminal 20 can synchronize the time between multiple STA functions that constitute the multilink without having to perform time synchronization for each STA function using beacon signals. Consequently, the wireless system 1 according to this embodiment can quickly transmit and receive data after waking up the STA function in the Doze state while suppressing the power consumption of the terminal 20.

[0113] <4> Modified Examples of Embodiments The wireless system 1 described in the embodiment is merely an example, and various modifications are possible. The first, second, and third modifications of the embodiment will be described below in order.

[0114] <4-1> First Variation The wireless system 1 according to the first modified embodiment has a configuration in which each STA function always refers to a common local clock. Figures 20 and 21 show examples of the functions of the base station 10 and terminal 20 provided in the wireless system 1 according to the first modified embodiment, respectively.

[0115] As shown in Figure 20, the base station 10 of the first modified embodiment has a configuration in which the time information 131 in the wireless signal processing unit 130, the time information 141 in the wireless signal processing unit 140, and the time information 151 in the wireless signal processing unit 150 are omitted from the base station 10 of the embodiment.

[0116] As shown in Figure 21, the terminal 20 of the first modified embodiment has a configuration in which the time information 231 in the wireless signal processing unit 230, the time information 241 in the wireless signal processing unit 240, and the time information 251 in the wireless signal processing unit 250 are omitted from the terminal 20 of the embodiment. The other configurations of the wireless system 1 according to the first modified embodiment are the same as in the embodiment.

[0117] As described above, in the first modified embodiment, neither the base station 10 nor the terminal 20 holds time information for each STA function. In other words, the clock of each STA function of the base station 10 is shared with the shared time information 122 outside of the STA function. The clock of each STA function of the terminal 20 is shared with the shared time information 222 outside of the STA function. Even in such a case, each STA function can perform CSMA / CA, etc., by always referring to the shared time information.

[0118] Furthermore, in the first modified embodiment, since the shared time information is always referenced, the time synchronization for each STA function performed in the embodiment is omitted. For this reason, in the first modified embodiment, it is sufficient that the shared time information 122 of the base station 10 and the shared time information 222 of the terminal 20 are synchronized. As a result, the wireless system 1 according to the first modified embodiment can simplify the time synchronization operations compared to the embodiment.

[0119] <4-2> Second variation The wireless system 1 according to the second modified embodiment sets a primary link for multiple links constituting a multilink. Figure 22 shows an example of link management information 121 in the wireless system 1 according to the second modified embodiment. The link management information 121 shown in Figure 22 differs from the link management information 121 shown in Figure 12 in that STA1 is set as the primary link. The method of representing information regarding the primary link is not limited to this, and other methods may be applied.

[0120] The primary link is pre-configured, for example, when establishing a multilink between base station 10 and terminal 20. The STA function used for the primary link may be prioritized according to the frequency band, or according to the signal strength of the link. Furthermore, the primary link setting may be changed as appropriate after the multilink is established. For example, the signal strength of each link constituting the multilink may be monitored, and the primary link may be changed to the link with the highest signal strength as appropriate.

[0121] Figure 23 shows an example of a method for outputting a beacon signal at a base station 10 of a wireless system 1 according to a second modified embodiment. As shown in Figure 23, when a primary link is established between the base station 10 and the terminal 20, the primary link is used as the basis for time synchronization.

[0122] Specifically, when STA1 and STA2 of base station 10 constitute a multilink and multilink power saving is applied, the primary link is always set to the Awake state, and other links, for example, are set to the Doze state. Then, STA1 of base station 10, which corresponds to the primary link, intermittently transmits a beacon signal containing the reference time information for the multilink. STA1 of terminal 20, which corresponds to the primary link, updates the shared time information 222 using the reference time information contained in the beacon signal. The other configurations and operations of the wireless system 1 according to the second modification of the embodiment are the same as in the embodiment.

[0123] As described above, by setting the primary link, the wireless system 1 according to the second modified embodiment can simplify the processing related to multilink time synchronization compared to the embodiment.

[0124] <4-3> Third Variation The wireless system 1 according to the third modification of the embodiment establishes a multilink similar to that of the embodiment using multiple channels CH included in the same frequency band. The multilink processing in the third modification of the embodiment is the same as the multilink processing of the embodiment, except that the channels used for multilink are changed to multiple channels CH included in the same frequency band.

[0125] Figure 24 shows an example of frequency bands used for wireless communication in wireless system 1 according to a third modified embodiment. As shown in Figure 24, for example, the 2.4GHz band, 5GHz band, and 6GHz band are used for wireless communication. Each frequency band contains multiple channels. In this example, it is assumed that each of the 2.4GHz band, 5GHz band, and 6GHz band contains at least three channels CH1, CH2, and CH3. Communication using each channel CH is realized by the associated STA function.

[0126] Figure 25 shows an example of link management information 121 in a wireless system 1 according to a third modified example of the embodiment. As shown in Figure 25, the link management information 121 in the third modified example of the embodiment has a configuration in which information regarding channel IDs for each frequency band is added to the link management information 121 in the embodiment. In this example, a multilink similar to that in the embodiment is established using channel CH2 of “STA1” corresponding to the 6GHz frequency band and channel CH3 of “STA2” corresponding to the 6GHz frequency band.

[0127] As described above, the STA functions of the base station 10 and the terminal 20 may use the same frequency band. Furthermore, the multilink between the base station 10 and the terminal 20 may be established by multiple STA functions using the same frequency band. Specifically, multiple STA functions may configure a multilink using different channels CH in the 5GHz band, for example. Even in such a case, the wireless system 1 according to the third modification of the embodiment can achieve efficient communication and suppress power consumption, similar to the embodiment.

[0128] <5> others In the above embodiment, each STA function may notify the corresponding link management unit if the link cannot be maintained due to the movement of the terminal 20 or the like. The link management unit 220 of the terminal 20 may also change the multilink status with the link management unit 120 of the base station 10 based on the notification from the STA function. Specifically, for example, the link management unit 220 of the terminal 20 and the link management unit 120 of the base station 10 may appropriately change the STA function used for multilink. When the multilink status is changed, the link management units 120 and 220 update the link management information 121 and 221, respectively. The link management units 120 and 220 may also update the association between traffic and STA functions in accordance with the increase or decrease in the number of links.

[0129] The configuration of the wireless system 1 according to this embodiment is merely an example, and other configurations are possible. For example, the example given is one in which each of the base station 10 and the terminal 20 is equipped with three STA functions (wireless signal processing units), but it is not limited to this. The base station 10 only needs to be equipped with at least two wireless signal processing units. Similarly, the terminal 20 only needs to be equipped with at least two wireless signal processing units. The number of channels that each STA function can process can be appropriately set according to the frequency band used. Each of the wireless communication modules 14 and 24 may support wireless communication on multiple frequency bands using multiple communication modules, or it may support wireless communication on multiple frequency bands using a single communication module.

[0130] Furthermore, the functional configurations of the base station 10 and terminal 20 in the wireless system 1 according to this embodiment are merely examples. The functional configurations of the base station 10 and terminal 20 may be named and grouped in other ways, as long as they are capable of performing the operations described in each embodiment. For example, in the base station 10, the data processing unit 110 and the link management unit 120 may 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 may be collectively referred to as the data processing unit.

[0131] Furthermore, in the wireless system 1 according to the embodiment, the CPUs included in the base station 10 and the terminal 20 may be other circuits. For example, an MPU (Micro Processing Unit) or the like may be used instead of a CPU. Also, each of the processes described in each embodiment may be implemented by dedicated hardware. The wireless system 1 according to each embodiment may have a mixture of processes executed by software and processes executed by hardware, or it may have only one or the other.

[0132] The flowcharts used to describe the operation in each embodiment are merely examples. The order of the operations described in the embodiments may be rearranged to the extent possible, and other operations may be added. Furthermore, the wireless frame format described in the above embodiments is merely an example. The wireless system 1 may use other wireless frame formats as long as it is capable of performing the operations described in each embodiment.

[0133] Furthermore, the present invention is not limited to the embodiments described above, and can be modified in various ways during implementation without departing from its essence. Also, each embodiment may be combined as appropriate, and in that case, the combined effects can be obtained. Moreover, the above embodiments include various inventions, and various inventions can be extracted by selecting combinations from the multiple disclosed constituent elements. For example, if the problem can be solved and effects obtained even if some constituent elements are deleted from all the constituent elements shown in the embodiment, then the configuration with these deleted constituent elements can be extracted as an invention. [Explanation of Symbols]

[0134] 1… Wireless system 10...Base station 20… Terminal 30… Server 11,21…CPU 12,22…ROM 13,23…RAM 14,24… Wireless communication module 15…Wired communication module 25…Display 2 hours… storage 110,210…Data Processing Unit 120,220… Link Management Department 121,221… Link management information 122,222…Shared time information 123...Data Categorization Department 124... Send queue 125…CSMA / CA Execution Department 126...Data Conflict Management Department 130, 140, 150, 230, 240, 250… Wireless signal processing unit 131,141,151,231,241,251…Time information

Claims

1. A first wireless signal processing unit configured to transmit and receive wireless signals using a first channel, The system includes a second wireless signal processing unit configured to transmit and receive wireless signals using a second channel different from the first channel, A multilink is established with the terminal using the first wireless signal processing unit and the second wireless signal processing unit. The first wireless signal processing unit holds first time information, the second wireless signal processing unit holds second time information, and the first time information and the second time information are synchronized. The first wireless signal processing unit stores the first traffic, and the second wireless signal processing unit stores the second traffic. The first wireless signal processing unit transmits a beacon signal capable of indicating the first time information, information indicating that the first traffic has been accumulated, and information indicating that the second traffic has been accumulated. The second wireless signal processing unit receives a frame from the terminal requesting the transmission of the second traffic based on the beacon signal, and transmits the second traffic to the terminal based on the received frame. Base station.

2. The system further comprises a plurality of wireless signal processing units, including the first wireless signal processing unit and the second wireless signal processing unit, The beacon signal is transmitted from the first wireless signal processing unit among the plurality of wireless signal processing units, and not from the second wireless signal processing unit. The base station according to claim 1.

3. The first time information and the second time information are the same time information. The base station according to claim 1.

4. A first wireless signal processing unit configured to transmit and receive wireless signals using a first channel, The system includes a second wireless signal processing unit configured to transmit and receive wireless signals using a second channel different from the first channel, A multilink is established with the base station using the first wireless signal processing unit and the second wireless signal processing unit. The first wireless signal processing unit holds first time information, the second wireless signal processing unit holds second time information, and the first time information and the second time information are synchronized. In the base station, a first traffic associated with the first radio signal processing unit and a second traffic associated with the second radio signal processing unit are stored. The first wireless signal processing unit receives a beacon signal that includes information for synchronizing the first time information with the base station, information indicating whether or not the first traffic has been accumulated, and information indicating whether or not the second traffic has been accumulated. The second wireless signal processing unit transmits a frame to the base station requesting the transmission of the second traffic based on the beacon signal, and receives the second traffic transmitted from the base station based on the frame. Terminal.

5. The system further comprises a plurality of wireless signal processing units, including the first wireless signal processing unit and the second wireless signal processing unit, The beacon signal is received by the first wireless signal processing unit among the plurality of wireless signal processing units, but not by the second wireless signal processing unit. The terminal according to claim 4.

6. The first time information and the second time information are the same time information. The terminal according to claim 4.

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