Base Bureau

Abstract

A base station (10) according to an embodiment comprises a first wireless signal processing unit (130), a second wireless signal processing unit (140), and a beacon management unit (122). 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 beacon management unit manages the transmission of beacons by the first wireless signal processing unit so that a first beacon is periodically transmitted from the first wireless signal processing unit, and manages the transmission of beacons by the second wireless signal processing unit so that the first beacon and a second beacon including information that has become more simplified than information included in the first beacon are periodically switched and transmitted from the second wireless signal processing unit.

Description

[Technical field]

[0001] The embodiment relates to a base station. [Background technology]

[0002] Wireless LAN (Local Area Network) is known as a wireless system that wirelessly connects a base station and a terminal. In addition, a multi-link that wirelessly connects a base station and a terminal using multiple types of bands (channels) may be used in a wireless LAN. Beacons may be used for setting up such a multi-link and for notifying operation information of the multi-link. [Prior art documents] [Non-patent literature]

[0003] [Non-Patent Document 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 [Problem to be solved by the invention]

[0004] The embodiment provides a base station that can efficiently transmit beacons using multiple channels. [Means for solving the problem]

[0005] The base station of the embodiment includes a first wireless signal processing unit, a second wireless signal processing unit, and a beacon management unit. The first wireless signal processing unit is configured to be able to transmit and receive wireless signals using a first channel. The second wireless signal processing unit is configured to be able to transmit and receive wireless signals using a second channel different from the first channel. The beacon management unit manages the transmission of beacons by the first wireless signal processing unit so that the first beacon is periodically transmitted from the first wireless signal processing unit, and manages the transmission of beacons by the second wireless signal processing unit so that the first beacon and a second beacon including information simplified more than information included in the first beacon are periodically switched and transmitted from the second wireless signal processing unit. Effect of the Invention

[0006] According to the embodiment, a base station is provided that can efficiently transmit beacons using multiple channels. [Brief description of the drawings]

[0007] [Figure 1] FIG. 1 is a diagram illustrating an example of a configuration of a wireless system according to an embodiment. [Diagram 2] FIG. 2 is a diagram showing a specific example of a format of a MAC frame used in communication between a base station and a terminal in the wireless system according to the embodiment. [Diagram 3] FIG. 3 is a diagram illustrating an example of the configuration of a base station. [Figure 4] FIG. 4 is a diagram illustrating an example of a functional configuration of the base station. [Diagram 5] FIG. 5 is a diagram illustrating an example of the configuration of a terminal. [Figure 6] FIG. 6 is a diagram illustrating an example of a functional configuration of the terminal. [Figure 7] FIG. 7 is a flowchart showing an example of a multi-link setup process in the wireless system according to the embodiment. [Figure 8] FIG. 8 is a diagram illustrating an example of information included in a normal beacon. [Figure 9]FIG. 9 is a diagram illustrating an example of a frame format of the management frame. [Figure 10] FIG. 10 is a diagram showing an example of information included in a simple beacon. [Figure 11] FIG. 11 is a diagram illustrating an example of a frame format of the S1G beacon frame. [Figure 12] FIG. 12 is a flowchart showing the beacon selection process for each channel. [Figure 13] FIG. 13 is a flowchart showing the beacon selection process for each period. [Figure 14] FIG. 14 is a diagram showing beacons transmitted on channels used as anchor links and other channels not used as anchor links. [Figure 15] FIG. 15 is a flowchart showing a beacon selection process for each channel in the first modification. [Figure 16] FIG. 16 is a diagram showing beacons transmitted on a channel used as an anchor link and on other channels not used as anchor links in the first modification. [Figure 17] FIG. 17 is a flowchart showing a beacon selection process for each period in the second modification. [Figure 18] FIG. 18 is a diagram showing beacons transmitted on channels used as anchor links and other channels not used as anchor links in the second modification. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] Hereinafter, an embodiment will be described with reference to the drawings. Fig. 1 is a diagram showing an example of a configuration of a wireless system 1 according to an embodiment. As shown in Fig. 1, the wireless system 1 includes, for example, a base station 10, a terminal 20, and a server 30.

[0009] The base station 10 is connected to a network NW and is used as an access point (AP) of a wireless LAN. For example, the base station 10 can wirelessly distribute data received from the network NW to the terminal 20. The base station 10 can also be connected to the terminal 20 using one type of band or multiple types of bands. In this specification, a wireless connection using multiple types of bands between the base station 10 and the terminal 20 is called a "multi-link." The communication between the base station 10 and the terminal 20 is based on, for example, the IEEE802.11 standard. Here, the communication based on the IEEE802.11 standard is described as an example, but is not limited to this.

[0010] The terminal 20 is a wireless terminal such as a smartphone or a tablet PC. The terminal 20 can transmit and receive data to and from a server 30 on a network NW via a base station 10 connected wirelessly. The terminal 20 may be other electronic devices such as a desktop computer or a laptop computer. The terminal 20 is required to be at least capable of communicating with the base station 10.

[0011] The server 30 can hold various information, for example, data of content targeted for the terminal 20. The server 30 is connected to the network NW by wire, for example, and is configured to be able to communicate with the base station 10 via the network NW. Note that it is sufficient for the server 30 to be able to communicate with at least the base station 10. In other words, the communication between the base station 10 and the server 30 may be wired or wireless.

[0012] In the wireless system 1 according to the embodiment, wireless communication between the base station 10 and the terminal 20 complies with the IEEE 802.11 standard. The IEEE 802.11 standard specifies the first and second MAC sublayers of the OSI (Open Systems Interconnection) reference model. In the OSI reference model, communication functions are divided into seven layers (first layer: physical layer, second layer: data link layer, third layer: network layer, fourth layer: transport layer, fifth layer: session layer, sixth layer: presentation layer, seventh layer: application layer). The data link layer includes, for example, an LLC (Logical Link Control) layer and a MAC (Media Access Control) layer. In the LLC layer, for example, a DSAP (Destination Service Access Point) header, an SSAP (Source Service Access Point) header, or the like is added to data input from an upper application to form an LLC packet. In the MAC layer, for example, a MAC header is added to an LLC packet to form a MAC frame. This explanation focuses on the processing of the MAC sublayers of layers 1 and 2 defined by the IEEE 802.11 standard, and omits explanations of the processing of other layers.

[0013] Fig. 2 is a diagram showing a specific example of a format of a MAC frame used in communication between the base station 10 and the terminal 20 in the wireless system 1 according to the embodiment. As shown in Fig. 2, the MAC frame includes, for example, a Frame Control field, a Duration field, an Address1 field, an Address2 field, an Address3 field, a Sequence Control field, an Address4 field, a QoS Control field, an HT Control field, a Frame Body field, and an FCS (Frame Check Sequence) field. Some of these fields are included, while others are not, depending on the type of wireless frame.

[0014] The Frame Control field through the HT Control field correspond to the MAC header. The Frame Body field corresponds to the MAC payload. The FCS field stores an error detection code for the MAC header and Frame Body field. The FCS field is used to determine whether there is an error in the MAC frame.

[0015] The Frame Control field includes various control information, such as a Type value, a Subtype value, a To DS (Distribution System) value, and a From DS value. The Type value indicates whether the MAC frame is a management frame, a control frame, or a data frame. The Subtype value indicates the frame type of the MAC frame when used in combination with the Type value. For example, "00 / 1000 (Type value / Subtype value)" indicates that the MAC frame is a beacon. Also, "00 / 0100 (Type value / Subtype value)" indicates that the MAC frame is a probe request. Also, "00 / 0101 (Type value / Subtype value)" indicates that the MAC frame is a probe response. The To DS value and the From DS value have different meanings depending on their combination. For example, when the MAC frame is a data frame, the To DS value "0" indicates that the receiving station is a terminal, and "1" indicates that the receiving station is a base station. Furthermore, when the MAC frame is a data frame, the From DS value "0" indicates that the transmitting station is a terminal, and "1" indicates that the transmitting station is a base station. On the other hand, when the MAC frame is a management frame or a control frame, the To DS value and From DS value are fixed to, for example, "0."

[0016] The Duration field indicates the planned period for which the wireless line is to be used. The Address field indicates the BSSID, source MAC address, destination MAC address, sender terminal address, receiver terminal address, etc. The number of Address fields used varies depending on the frame type. The Sequence Control field indicates the sequence number of the MAC frame and the fragment number for fragmentation. The QoS Control field is used for the QoS (Quality of Service) function in the MAC frame. The QoS Control field may include a traffic type (TID) subfield. The HT Control field is a control field for high throughput function. The Frame Body field contains information according to the frame type. For example, when the frame type is a data frame, the Frame Body field stores the transmission data.

[0017] Fig. 3 is a diagram showing an example of the configuration of the base station 10. As shown in Fig. 3, the 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 module 14, and a wired communication module 15.

[0018] 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 and 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 working area for the CPU 11. The wireless communication module 14 is a circuit used for transmitting and receiving data by wireless signals and is connected to an antenna. The wireless communication module 14 also includes, for example, a plurality of communication modules each corresponding to a plurality of frequency bands. The wired communication module 15 is a circuit used for transmitting and receiving data by wired signals and is connected to a network NW.

[0019] Fig. 4 is a diagram showing an example of the functional configuration of the base station 10. As shown in Fig. 4, the base station 10 includes, for example, an LLC processing unit 110, a link management unit 120, and radio signal processing units 130, 140, and 150. The LLC processing unit 110, the link management unit 120, and the radio signal processing units 130, 140, and 150 are realized by a wireless communication module 14 or a combination of a CPU 11 and the wireless communication module 14.

[0020] The LLC processing unit 110 may execute LLC layer processing on the input data. For example, the LLC processing unit 110 generates an LLC packet by adding a DSAP (Destination Service Access Point) header and an SSAP (Source Service Access Point) header to the data input from the server 30 via the network NW. The LLC processing unit 110 then outputs the LLC packet to the link management unit 120. The LLC processing unit 110 also extracts data from the MAC frame input from the link management unit 120. The LLC processing unit 110 then transmits the data to the server 30 via the network NW.

[0021] The link management unit 120 may execute, for example, MAC layer processing on the input data. The link management unit 120 also manages links with the terminal 20 based on notifications from the wireless signal processing units 130, 140, and 150. The link management unit 120 includes a data processing unit 121, a beacon management unit 122, a management unit 123, and a MAC frame processing unit 124.

[0022] When the data processing unit 121 receives an LLC packet from the LLC processing unit 110, it generates a MAC frame by adding a MAC header to the LLC packet. Then, the data processing unit 121 outputs the MAC frame to the MAC frame processing unit 124. When the data processing unit 121 receives a MAC frame from the MAC frame processing unit 124, it extracts an LLC packet from the MAC frame. Then, the data processing unit 121 outputs the LLC packet to the LLC processing unit 110. When divided data is transmitted from a plurality of radio signal processing units by multilink, the data processing unit 121 rearranges MPDUs (MAC Protocol Data Units) restored from the MAC frame received from the MAC frame processing unit 124 according to sequence numbers. Then, when the data processing unit 121 has rearranged the order, it outputs the LLC packet to the LLC processing unit 110. Note that the rearrangement of the MPDUs may be performed by a unit other than the data processing unit 121.

[0023] The beacon management unit 122 manages the transmission of beacons for each link. The beacon management unit 122 manages, for example, the transmission period of beacons for each link. The beacon management unit 122 also manages, for example, whether the beacon transmitted for each link is a normal beacon or a simple beacon. A normal beacon is a beacon that includes all information used for setting up a multi-link, etc. A simple beacon is a beacon that includes simplified information compared to a normal beacon. A normal beacon and a simple beacon will be described in detail later.

[0024] The management unit 123 manages links with the terminal 20 based on notifications received from the wireless signal processing units 130, 140, and 150 via the MAC frame processing unit 124. For example, the management unit 123 performs multi-link setup in response to a request from the terminal 20 via any of the wireless signal processing units 130, 140, and 150. In the multi-link setup, when the management unit 123 receives a connection request from the terminal 20 via any of the wireless signal processing units 130, 140, and 150, it executes a protocol related to association. Then, following the connection request, the management unit 123 executes a protocol related to authentication.

[0025] When the MAC frame processing unit 124 receives a MAC frame from the data processing unit 121, it temporarily stores the received MAC frame. Then, the MAC frame processing unit 124 performs carrier sense for a random time to check the status of the channel used in the link transmitting the wireless signal. When the channel is free, the MAC frame processing unit 124 outputs the MAC frame to one of the wireless signal processing units 130, 140, and 150 that corresponds to the link transmitting the wireless signal. Furthermore, when the MAC frame processing unit 124 receives a MAC frame from the wireless signal processing unit 130, 140, or 150, it outputs the received MAC frame to the data processing unit 121.

[0026] Each of the radio signal processing units 130, 140, and 150 may perform, for example, physical layer processing on the input radio signal. That is, each of the radio signal processing units 130, 140, and 150 handles transmission and reception of radio signals between the base station 10 and the terminal 20. The radio signal processing unit 130 handles radio signals in the 2.4 GHz band. The radio signal processing unit 140 handles radio signals in the 5 GHz band. The radio signal processing unit 150 handles radio signals in the 6 GHz band. The radio signal processing units 130, 140, and 150 may or may not share an antenna of the base station 10.

[0027] For example, when each of the wireless signal processing units 130, 140, and 150 receives a MAC frame from the MAC frame processing unit 124, it generates a PHY frame by adding a PHY (physical) header to the MAC frame. Then, each of the wireless signal processing units 130, 140, and 150 performs a predetermined modulation operation on the PHY frame to convert the PHY frame into a wireless signal, and transmits the wireless signal via an antenna. The predetermined modulation operation includes, for example, convolutional coding, interleaving, subcarrier modulation, Inverse Fast Fourier Transform (IFFT), Orthogonal Frequency Division Multiplexing (OFDM) modulation, and frequency conversion.

[0028] Furthermore, when receiving a radio signal via an antenna, each of the radio signal processing units 130, 140, and 150 performs a predetermined demodulation operation on the received radio signal to restore the PHY frame. The predetermined demodulation operation includes, for example, frequency conversion, OFDM demodulation, Fast Fourier Transform (FFT), subcarrier demodulation, deinterleaving, and Viterbi decoding. Each of the radio signal processing units 130, 140, and 150 then extracts a MAC frame from the PHY frame and outputs the extracted MAC frame to the MAC frame processing unit 124.

[0029] Fig. 5 is a diagram showing an example of the configuration of the terminal 20. As shown in Fig. 5, the terminal 20 includes a CPU 21, a ROM 22, a RAM 23, a wireless communication module 24, a display 25, and a storage 26, for example.

[0030] 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 and holds programs and control data for controlling the terminal 20. The RAM 23 is, for example, a volatile semiconductor memory and is used as a working area for the CPU 21. The wireless communication module 24 is a circuit used for transmitting and receiving data by wireless signals and is connected to an antenna. The wireless communication module 24 also includes, for example, a plurality of communication modules each corresponding to a plurality of frequency bands. The display 25 displays a GUI (Graphical User Interface) or the like corresponding to application software. The display 25 may have a function as an input interface for the terminal 20. The storage 26 is a non-volatile storage device and holds system software and the like for the terminal 20.

[0031] Fig. 6 is a diagram showing an example of a functional configuration of the terminal 20. As shown in Fig. 6, the terminal 20 includes, for example, an LLC processing unit 210, a link management unit 220, radio signal processing units 230, 240, and 250, and an application execution unit 260. The LLC processing unit 210, the link management unit 220, the radio signal processing units 230, 240, and 250 are realized by the wireless communication module 24, or a combination of the CPU 21 and the wireless communication module 24. Furthermore, the application execution unit 260 is realized by the CPU 21.

[0032] The LLC processing unit 210 may execute LLC layer processing on the input data. For example, the LLC processing unit 210 generates an LLC packet by adding a DSAP header, an SSAP header, and the like to the data input from the application execution unit 260. The LLC processing unit 210 then outputs the LLC packet to the link management unit 220. The LLC processing unit 210 also extracts data from the MAC frame input from the link management unit 220. The LLC processing unit 210 then outputs the data to the application execution unit 260.

[0033] The link management unit 220 may execute, for example, MAC layer processing on the input data. The link management unit 220 also manages links with the base station 10 based on notifications from the radio signal processing units 230, 240, and 250. The link management unit 220 includes a data processing unit 221, a management unit 223, and a MAC frame processing unit 224.

[0034] When the data processing unit 221 receives an LLC packet from the LLC processing unit 210, the data processing unit 221 generates a MAC frame by adding a MAC header to the LLC packet. Then, the data processing unit 221 outputs the MAC frame to the MAC frame processing unit 224. When the data processing unit 221 receives a MAC frame from the MAC frame processing unit 224, the data processing unit 221 extracts the LLC packet from the MAC frame. Then, the data processing unit 221 outputs the LLC packet to the LLC processing unit 210. When divided data is transmitted from a plurality of radio signal processing units by multilink, the data processing unit 221 rearranges the MPDUs restored from the MAC frame received from the MAC frame processing unit 224 according to the sequence numbers. Then, the data processing unit 221 outputs the LLC packet to the LLC processing unit 210 when the rearrangement is completed. Note that the rearrangement of the MPDUs may be performed by a unit other than the data processing unit 221.

[0035] The management unit 223 manages the links with the base station 10 based on notifications received from the wireless signal processing units 230, 240, and 250 via the MAC frame processing unit 224. For example, the management unit 223 makes a multi-link connection request to the base station 10 via any of the wireless signal processing units 230, 240, and 250. Furthermore, the management unit 223 executes a protocol related to association and a protocol related to authentication in response to a request from the base station 10 via any of the wireless signal processing units 230, 240, and 250.

[0036] When the MAC frame processing unit 224 receives a MAC frame from the data processing unit 221, it temporarily stores the received MAC frame. Then, the MAC frame processing unit 224 performs carrier sense for a random time to check the status of the channel used in the link transmitting the wireless signal. When the channel is free, the MAC frame processing unit 224 outputs the MAC frame to one of the wireless signal processing units 230, 240, 250 that corresponds to the link transmitting the wireless signal. Furthermore, when the MAC frame processing unit 224 receives a MAC frame from the wireless signal processing unit 230, 240, 250, it outputs the received MAC frame to the data processing unit 221.

[0037] Each of the radio signal processing units 230, 240, and 250 may perform, for example, physical layer processing on the input radio signal. That is, each of the radio signal processing units 230, 240, and 250 handles transmission and reception of radio signals between the base station 10 and the terminal 20. The radio signal processing unit 230 handles radio signals in the 2.4 GHz band. The radio signal processing unit 240 handles radio signals in the 5 GHz band. The radio signal processing unit 250 handles radio signals in the 6 GHz band. The radio signal processing units 230, 240, and 250 may or may not share an antenna of the terminal 20.

[0038] For example, when each of the wireless signal processing units 230, 240, and 250 receives a MAC frame from the MAC frame processing unit 224, it generates a PHY frame by adding a PHY header to the MAC frame. Then, each of the wireless signal processing units 230, 240, and 250 performs a predetermined modulation operation on the PHY frame to convert the PHY frame into a wireless signal, and transmits the wireless signal via an antenna. The predetermined modulation operation includes, for example, convolutional coding, interleaving, subcarrier modulation, inverse fast Fourier transform, OFDM modulation, and frequency conversion.

[0039] Furthermore, when receiving a radio signal via an antenna, each of the radio signal processors 230, 240, and 250 performs a predetermined demodulation operation on the received radio signal to restore the PHY frame. The predetermined demodulation operation includes, for example, frequency conversion, OFDM demodulation, fast Fourier transform, subcarrier demodulation, deinterleaving, and Viterbi decoding. Each of the radio signal processors 230, 240, and 250 then extracts a MAC frame from the PHY frame and outputs the extracted MAC frame to the MAC frame processor 224.

[0040] The application execution unit 260 executes an application capable of using the data input from the LLC processing unit 210. For example, the application execution unit 260 can display information about the application on the display 25. The application execution unit 260 can also operate based on an operation of an input interface.

[0041] 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, the wireless signal processing units 130 and 230 can be wirelessly connected to each other using the 2.4 GHz band. The wireless signal processing units 140 and 240 can be wirelessly connected to each other using the 5 GHz band. The wireless signal processing units 150 and 250 can be wirelessly connected to each other using the 6 GHz band. In this specification, each wireless signal processing unit may be called an "STA function." That is, the wireless system 1 according to the embodiment has a plurality of STA functions. Here, in the following description, the link between the wireless signal processing units 130 and 230 may be referred to as link #1, the link between the wireless signal processing units 140 and 240 may be referred to as link #2, and the link between the wireless signal processing units 150 and 250 may be referred to as link #3.

[0042] Next, an example of an operation related to the multilink of the wireless system 1 according to the embodiment will be described. Fig. 7 is a flowchart showing an example of a multilink setup process in the wireless system 1 according to the embodiment.

[0043] In the process of step S10, the terminal 20 transmits a probe request to the base station 10. The probe request is a signal for confirming whether or not a base station 10 exists in the vicinity of the terminal 20. The Frame Control field of the probe request contains, for example, "00 / 0100 (Type value / Subtype value)". Upon receiving the probe request, the base station 10 executes the process of step S11.

[0044] In the process of step S11, the base station 10 transmits a probe response to the terminal 20. The probe response is a signal that the base station 10 uses to respond to a probe request from the terminal 20. The Frame Control field of the probe response contains, for example, "00 / 0101 (Type value / Subtype value)". Upon receiving the probe response, the terminal 20 executes the process of step S12. Here, the probe response contains information necessary for establishing a multi-link equivalent to a normal beacon, which will be described later.

[0045] In the process of step S12, the terminal 20 transmits an association request to the base station 10 via at least one STA function. The association request includes a signal for requesting the base station 10 to establish a multi-link. For example, the association request is generated by the link management unit 220 of the terminal 20. The Frame Control field of the association request includes, for example, "00 / 0000 (Type value / Subtype value)". When the link management unit 120 of the base station 10 receives the association request including the signal for requesting the establishment of a multi-link, it executes the process of step S13. Note that the association request may be a normal association request to which information for a multi-link connection is added.

[0046] In the process of step S13, the management unit 123 of the base station 10 executes a multi-link association process using one STA function. Specifically, the base station 10 first executes an association process of a first STA function with the terminal 20. Then, when a wireless connection (link) is established in the first STA function, the management unit 123 of the base station 10 executes an association process of a second STA function using the first STA function with which the link is established. In other words, the STA function with which the link is established is used for the association process of the STA function with which the link is not established. When the association processes of at least two STA functions are completed, the base station 10 establishes a multi-link and executes the process of step S14.

[0047] In the process of step S14, the management unit 123 of the base station 10 updates the link management information. The link management information includes information indicating whether or not a link using the corresponding STA function is established for each ID of the STA function, information on the frequency band (channel) handled by the corresponding STA function, information indicating whether or not the corresponding STA function is used for an anchor link, and information on the traffic type of data handled by the link of the corresponding STA function. Here, the anchor link is a link that is distinguished from other links and performs a special operation in addition to a general operation. For example, the special operation is transmission and reception of control information related to the operation of the multilink. As will be described later, the control information related to the operation of the multilink includes multilink capability information, anchor link information, and operation information for each link. The anchor link may be set by the management unit 123.

[0048] In the process of step S15, the base station 10 transmits a multi-link establishment response to the terminal 20. The multi-link establishment response is a signal used by the base station 10 to respond to a multi-link request from the terminal 20. The Frame Control field of the multi-link establishment response contains, for example, "00 / 0001 (Type value / Subtype value)". Based on the reception of the multi-link establishment response, the link management unit 220 of the terminal 20 recognizes that a multi-link with the base station 10 has been established. Upon receiving the multi-link establishment response, the terminal 20 executes the process of step S16.

[0049] In the process of step S16, the management unit 223 of the terminal 20 updates the link management information. The link management information managed in the terminal 20 may be the same as the link management information managed in the base station 10.

[0050] The multi-link setup is completed by updating the link management information in both the base station 10 and the terminal 20. After that, data communication using the multi-link becomes possible between the base station 10 and the terminal 20. For example, input data can be distributed and transmitted over multiple links. Also, when a channel of a certain link is not available, data can be transmitted using another link.

[0051] 7, a connection process for establishing a multi-link is performed after a probe request from the terminal 20 and a probe response from the base station 10. Alternatively, the base station 10 may periodically transmit a beacon, and the terminal 20 receiving the beacon may transmit an association request for establishing a multi-link, thereby performing a connection process for establishing a multi-link.

[0052] Next, a beacon transmission process by the base station 10 will be described. In the embodiment, the base station 10 periodically transmits a beacon using each channel. At this time, the beacon management unit 122 performs a beacon selection process for each channel and a beacon selection process for each period to manage the settings of the beacon transmission. The MAC frame processing unit 124 transmits either a normal beacon or a simple beacon using each channel based on the settings of the beacon transmission managed by the beacon management unit 122.

[0053] Fig. 8 is a diagram showing an example of information included in a normal beacon. A normal beacon in an embodiment includes information necessary for establishing and operating a multi-link. As shown in Fig. 8, a normal beacon includes multi-link capability information, anchor link information, operation information of link #1, operation information of link #2, and operation information of link #3. A normal beacon may include information other than that shown in Fig. 8.

[0054] The multilink capability information is information indicating whether the base station 10 can set up a multilink. For example, when the multilink capability information is "0", it indicates that a multilink cannot be set up. On the other hand, when the multilink capability information is "1", it indicates that a multilink can be set up.

[0055] The anchor link information is information indicating the ID of an anchor link. In the case of having three STA functions like the base station 10 of the embodiment, the anchor link information may be one of three numerical values, for example, "0", "1", and "2". In this case, for example, when the anchor link information is "0", it indicates that link #1 is the anchor link. Also, when the anchor link information is "1", it indicates that link #2 is the anchor link. Also, when the anchor link information is "2", it indicates that link #3 is the anchor link.

[0056] The operational information for link #1 indicates operational parameters used in link #1. The operational information for link #2 indicates operational parameters used in link #2. The operational information for link #3 indicates operational parameters used in link #3. The operational parameters include, for example, access parameters of Enhanced Distributed Channel Access (EDCA).

[0057] A normal beacon can be transmitted using, for example, a management frame. FIG. 9 is a diagram showing an example of a frame format of a management frame. As shown in FIG. 9, the management frame includes, for example, a Frame Control field, a Duration field, an Address1 field, an Address2 field, an Address3 field, a Sequence Control field, an HT Control field, a Frame Body field, and an FCS (Frame Check Sequence) field. As described above, when a management frame is used as a beacon frame, the Frame Control field includes "00 / 1000 (Type value / Subtype value)". The information shown in FIG. 9 is stored in, for example, a Frame Body field of the beacon frame.

[0058] On the other hand, Fig. 10 is a diagram showing an example of information included in a simple beacon. As shown in Fig. 10, the simple beacon includes simplified information. The simplified information is information in which at least a part of the information elements included in a normal beacon is included in a simplified state. The simplification includes omission, replacement, etc. of a part of the information elements included in the normal beacon.

[0059] The simple beacon may be, for example, an S1G (Sub 1 Giga) beacon frame defined in IEEE802.ah. FIG. 11 shows an example of a frame format of an S1G beacon frame. S1G Capabilities defined in the Frame Body field of the S1G beacon frame may be used as simple multi-link capability information. Similarly, S1G Operation defined in the Frame Body field of the S1G beacon frame may be used as simple link operation information.

[0060] The simple beacon is not limited to be transmitted in the S1G beacon frame. The simple beacon may be transmitted using the FILS (Fast Initial Link Setup) method defined in IEEE802.ai. In this way, the simple beacon may be a beacon of any method that can be transmitted in a shorter time than a normal beacon.

[0061] FIG. 12 is a flowchart showing the beacon selection process for each channel.

[0062] In step S20, the beacon management unit 122 sets a parameter n to 1. The parameter n is a parameter indicating the ID of a channel used by the base station 10. For example, when the base station 10 uses three channels, channel #1, channel #2, and channel #3, the parameter n can take three values, 0, 1, and 2.

[0063] In step S21, the beacon management unit 122 determines whether the parameter n matches the ID of the anchor link. If it is determined in step S21 that the parameter n matches the ID of the anchor link, the process proceeds to step S22. If it is determined in step S21 that the parameter n does not match the ID of the anchor link, the process proceeds to step S23.

[0064] In step S22, the beacon management unit 122 sets the normal beacon to be transmitted periodically on the channel #n. In step S23, the beacon management unit 122 sets the beacon selection process to be performed periodically on the channel #n. After step S22 or step S23, the process proceeds to step S24.

[0065] In step S24, the beacon management unit 122 judges whether the parameter n has reached a threshold value nmax. The threshold value nmax is the number of channels used by the base station 10. For example, when the base station 10 uses three channels, namely, channel #1, channel #2, and channel #3, the threshold value nmax is 3. When it is judged in step S24 that the parameter n has not reached the threshold value nmax, the process proceeds to step S25. When it is judged in step S24 that the parameter n has reached the threshold value nmax, the beacon management unit 122 ends the process of FIG. 12.

[0066] In step S25, the beacon management unit 122 increments n by 1. After that, the beacon management unit 122 returns the process to step S21. In this case, the processes of steps S21-S24 are performed in the next channel.

[0067] FIG. 13 is a flowchart showing the beacon selection process for each period. The beacon selection process for each period is performed for each channel other than the channel used as the anchor link every time a default beacon transmission period elapses. For example, when the base station 10 uses three channels, channel #1, channel #2, and channel #3, and channel #1 is the channel used as the anchor link, the beacon selection process for each period is performed for channel #2 and channel #3. Here, when there are two or more channels not used as anchor links, the beacon selection process for each channel for each period may be performed in parallel or sequentially.

[0068] In step S30, the beacon management unit 122 determines whether the parameter m has reached mperiod. The parameter m is a parameter that indicates the current beacon transmission period. The initial value of the parameter m is, for example, 0. Moreover, mperiod is a threshold value that indicates the transmission period of a normal beacon in a channel that is not used as an anchor link. mperiod is, for example, a natural number. When it is determined in step S30 that the parameter m has reached the threshold mperiod, the process proceeds to step S31. When it is determined in step S30 that the parameter m has not reached the threshold mperiod, the process proceeds to step S33.

[0069] In step S31, the beacon management unit 122 sets the MAC frame processing unit 124 via the management unit 123 to transmit a normal beacon. In response to this, the MAC frame processing unit 124 generates a normal beacon and transmits the generated normal beacon via the STA function of the corresponding channel. The generation of the normal beacon may be performed by the data processing unit 121 instead of the MAC frame processing unit 124.

[0070] In step S32, the beacon management unit 122 resets the parameter m to 0. After that, the beacon management unit 122 ends the process of FIG.

[0071] In step S33, the beacon management unit 122 sets the MAC frame processing unit 124 via the management unit 123 to transmit a simple beacon. In response to this, the MAC frame processing unit 124 generates a simple beacon and transmits the generated simple beacon via the STA function of the corresponding channel. The generation of the simple beacon may be performed by the data processing unit 121 instead of the MAC frame processing unit 124.

[0072] In step S34, the beacon management unit 122 increments the parameter m by 1. After that, the beacon management unit 122 ends the processing of FIG.

[0073] Next, a transmission process of a normal beacon in a channel used as an anchor link will be described. For a channel used as an anchor link, the beacon management unit 122 sets the MAC frame processing unit 124 via the management unit 123 so as to transmit a normal beacon every time a specified beacon transmission period elapses. In response to this, the MAC frame processing unit 124 generates a normal beacon and transmits the generated normal beacon via the STA function of the channel used as the anchor link. The generation of the normal beacon may be performed by the data processing unit 121 instead of the MAC frame processing unit 124.

[0074] Fig. 14 is a diagram showing beacons transmitted on a channel used as an anchor link and other channels not used as anchor links. In Fig. 14, the channel used as the anchor link is channel #1, and the other channels are channel #2 and channel #3.

[0075] As shown in Fig. 14, normal beacons are transmitted at regular intervals on channel #1, which is an anchor link. On the other hand, simple beacons are transmitted on channels #2 and #3 in principle, and normal beacons are transmitted only at specific intervals.

[0076] Here, the specific period for transmitting a normal beacon may be changed individually depending on the link quality (channel utilization rate, frame transmission error rate, transmission ratio of high priority frames and low priority frames transmitted according to the channel, etc.) of each link for transmitting a beacon. For example, when the channel utilization rate is high, the frame transmission error rate is high, or the transmission ratio of high priority frames is high, the period for transmitting a normal beacon may be made longer than that of other channels. In this case, the value of the threshold mperiod is set depending on these link qualities and is different for each channel. This enables efficient beacon transmission according to the link quality. Note that a quality class may be defined based on each parameter of the link quality, and a quality class may be selected by periodically evaluating each parameter, and the value of the threshold mperiod associated with the quality class may be used.

[0077] As described above, according to the embodiment, a beacon including information related to a multilink is transmitted using a plurality of channels. By transmitting a beacon on a plurality of channels, information on the channel used for the link can be recognized by surrounding base stations and terminals with which no link has been established.

[0078] Here, transmitting beacons with a large amount of information on all channels may lead to a decrease in the operational efficiency of the channels as a wireless system. In response to this, in the embodiment, the beacon management unit 122 manages the transmission of beacons so that, for channels other than the channel used as the anchor link, normal beacons and simple beacons are switched and transmitted at a constant cycle. In this way, in the embodiment, the transmission efficiency of other channels can be improved by having the channel used as the anchor link mainly notify information necessary for the establishment and operation of the multi-link. In this way, in the embodiment, beacons can be efficiently transmitted using multiple channels.

[0079] [Variation 1] Hereinafter, a modification of the embodiment will be described. In the embodiment, it is assumed that a normal beacon is always transmitted on the channel used as the anchor link. In contrast, it may be set such that a simple beacon is also transmitted on the channel used as the anchor link. In this case, the transmission frequency of the normal beacon on the channel used as the anchor link is made higher than the transmission frequency of the normal beacon on the channel not used as the anchor link.

[0080] FIG. 15 is a flowchart showing the beacon selection process for each channel in Modification 1. In step S40, the beacon management unit 122 sets the parameter n to 1. The parameter n is a parameter indicating the ID of the channel used by the base station 10 described above.

[0081] In step S41, the beacon management unit 122 determines whether the parameter n matches the ID of the anchor link. When it is determined in step S41 that the parameter n matches the ID of the anchor link, the process proceeds to step S42. When it is determined in step S41 that the parameter n does not match the ID of the anchor link, the process proceeds to step S43.

[0082] In step S42, the beacon management unit 122 sets it so that the per-period beacon selection process is performed on channel #n. Also, the beacon management unit 122 sets the threshold mperiod in the per-period beacon selection process for channel #n to ma. In step S43, the beacon management unit 122 sets it so that the per-period beacon selection process is performed on channel #n. Also, the beacon management unit 122 sets the threshold mperiod in the per-period beacon selection process for channel #n to mo. Here, ma < mo. After step S42 or step S43, the process proceeds to step S44.

[0083] In step S44, the beacon management unit 122 judges whether the parameter n reaches a threshold nmax. The threshold nmax is the number of channels used by the base station 10 described above. When it is judged in step S44 that the parameter n does not reach the threshold nmax, the process proceeds to step S45. When it is judged in step S44 that the parameter n reaches the threshold nmax, the beacon management unit 122 ends the process of FIG. 15.

[0084] In step S45, the beacon management unit 122 increments n by 1. After that, the beacon management unit 122 returns the process to step S41. In this case, the processes of steps S41-S44 are performed in the next channel.

[0085] After the beacon selection process for each channel, the beacon management unit 122 performs the beacon selection process for each period for each channel including the channel used as the anchor link at each specified beacon transmission period. The beacon selection process for each period may be the same as that shown in FIG. 13. However, the value of the threshold mperiod in step S30 is different for each channel. That is, if the channel is used as an anchor link, the threshold ma is used, and if the channel is not used as an anchor link, the threshold mo is used.

[0086] Fig. 16 is a diagram showing beacons transmitted on a channel used as an anchor link and other channels not used as anchor links in Modification 1. In Fig. 16, the channel used as the anchor link is channel #1, and the other channels are channel #2 and channel #3.

[0087] As shown in FIG. 16, in Modification 1, normal beacons are transmitted at specific intervals during the transmission of the simple beacon on all of Channel #1, which is the channel used as the anchor link, and other channels, Channel #2 and Channel #3. However, since it is ma <mo, the transmission frequency of the normal beacon is higher for Channel #1.

[0088] Here, the specific interval for transmitting the normal beacon may be individually changed according to the link quality of each link for transmitting the beacon (channel utilization rate, frame transmission error rate, transmission ratio of high-priority frames and low-priority frames transmitted according to the channel, etc.). For example, when the channel utilization rate is high, the frame transmission error rate is high, and the transmission ratio of high-priority frames is high, the interval for transmitting the normal beacon may be made longer compared to other channels. In this case, the value of the threshold mo is set according to these link qualities and will be different for each channel. On the other hand, the value of the threshold ma is not changed. Thereby, efficient beacon transmission according to the link quality becomes possible. Note that a quality class may be defined based on each parameter of the link quality, the quality class may be selected by periodically evaluating each parameter, and the value of the threshold mo associated with the quality class may be used.

[0089] As described above, also in Modification 1, by mainly performing the notification of information necessary for establishing the multi-link on the channel used as the anchor link, the transmission efficiency on other channels can be increased. Furthermore, in Modification 1, since the simple beacon is also transmitted on the channel used as the anchor link, the transmission efficiency in the channel used as the anchor link can also be increased.

[0090] [Modification 2] Next, Modification 2 of the embodiment will be described. Modification 2 is an example in which the notification of information necessary for establishing the multi-link is evenly performed on each channel.

[0091] 17 is a flowchart showing a beacon selection process for each period in the modified example 2. The beacon selection process for each period in the modified example 2 is a process that is performed for each channel including a channel used as an anchor link. In the modified example 2, the beacon selection process for each channel is omitted.

[0092] In step S50, the beacon management unit 122 judges whether the parameter m matches the ID of the corresponding channel. The parameter m is a parameter indicating the ID of the channel used by the base station 10. The corresponding channel ID is the ID of the channel that is the target of the periodic beacon selection process being performed. For example, when the periodic beacon selection process is being performed for channel #1, the ID of the corresponding channel is 0. In step S50, when it is judged that the parameter m matches the ID of the corresponding channel, the process proceeds to step S51. In step S50, when it is judged that the parameter m does not match the ID of the corresponding channel, the process proceeds to step S52.

[0093] In step S51, the beacon management unit 122 sets the MAC frame processing unit 124 via the management unit 123 so as to transmit a normal beacon. In response to this, the MAC frame processing unit 124 generates a normal beacon and transmits the generated normal beacon via the STA function of the corresponding channel. The normal beacon may be generated by the data processing unit 121 instead of the MAC frame processing unit 124. In step S52, the beacon management unit 122 sets the MAC frame processing unit 124 via the management unit 123 so as to transmit a simple beacon. In response to this, the MAC frame processing unit 124 generates a simple beacon and transmits the generated simple beacon via the STA function of the corresponding channel. The simple beacon may be generated by the data processing unit 121 instead of the MAC frame processing unit 124.

[0094] In step S53, the beacon management unit 122 increments m by one.

[0095] In step S54, the beacon management unit 122 judges whether the parameter m reaches the threshold mmax. The threshold mmax is the number of channels used by the base station 10. When it is judged in step S54 that the parameter m does not reach the threshold mmax, the beacon management unit 122 returns the process to step S50. In this case, the process of steps S50-S54 is performed in the next channel. When it is judged in step S54 that the parameter m reaches the threshold mmax, the process proceeds to step S55.

[0096] In step S55, the beacon management unit 122 resets the parameter m to 0. After that, the beacon management unit 122 ends the process of FIG.

[0097] Fig. 18 is a diagram showing beacons transmitted on a channel used as an anchor link and other channels not used as anchor links in Modification 2. In Fig. 18, the channel used as the anchor link is channel #1, and the other channels are channel #2 and channel #3.

[0098] 18, in Modification 2, normal beacons are transmitted at specific periods between the transmission of simple beacons on channel #1, which is a channel used as an anchor link, and on all other channels, channel #2 and channel #3, in the same manner as in Modification 1. In Modification 2, the periods in which normal beacons are transmitted differ for each channel.

[0099] Here, the specific period for transmitting the normal beacon may be changed individually according to the link quality (channel utilization rate, frame transmission error rate, transmission ratio of high priority frames and low priority frames transmitted according to the channel, etc.) of each link for transmitting the beacon. For example, when the channel utilization rate is high, the frame transmission error rate is high, and the transmission ratio of high priority frames is high, the period for transmitting the normal beacon may be made longer than that of other channels. In this case, the value of the threshold mmax is set according to these link qualities and is different for each channel. This enables efficient beacon transmission according to the link quality. Note that a quality class may be defined based on each parameter of the link quality, and a quality class may be selected by periodically evaluating each parameter, and the value of the threshold mmax associated with the quality class may be used.

[0100] As described above, in the second modification, the information required for establishing a multi-link is not mainly notified by the channel used as the anchor link, but is notified equally by each channel. This can improve the transmission efficiency of each channel equally. In addition, since the transmission timing of the normal beacon is offset for each channel, the possibility of receiving the normal beacon including the multi-link information on any of the channels when the terminal scans is increased.

[0101] Moreover, the configuration of the wireless system 1 according to the embodiment and the modified example is merely an example, and other configurations may be used. For example, the base station 10 and the terminal 20 each have three STA functions (wireless signal processing units), but the present invention is not limited to this. The base station 10 only needs to have at least two wireless signal processing units. Similarly, the terminal 20 only needs to have at least two wireless signal processing units. Furthermore, the number of channels that each STA function can process may be appropriately set according to the frequency band used. Each of the wireless communication modules 14 and 24 may support wireless communication in multiple frequency bands by using multiple communication modules, or may support wireless communication in multiple frequency bands by using one communication module.

[0102] Furthermore, the functional configurations of the base station 10 and the terminal 20 in the wireless system 1 according to the embodiments and the modified examples thereof are merely examples. The functional configurations of the base station 10 and the terminal 20 may have other names and be grouped as long as they are capable of executing the operations described in each embodiment.

[0103] Furthermore, in the wireless system 1 according to the embodiment, the CPU included in each of 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. Furthermore, each of the processes described in each embodiment may be realized by dedicated hardware. The wireless system 1 according to each embodiment may include a mixture of processes executed by software and processes executed by hardware, or may include only one of them.

[0104] The present invention is not limited to the above-mentioned embodiment, and can be modified in various ways without departing from the gist of the present invention. The embodiments may be combined as appropriate, and in that case, the combined effect can be obtained. Furthermore, the above-mentioned embodiment includes various inventions, and various inventions can be extracted by combinations selected from the multiple components disclosed. For example, if the problem can be solved and the effect can be obtained even if some components are deleted from all the components shown in the embodiment, the configuration from which the components are deleted can be extracted as an invention. [Explanation of symbols]

[0105] 1. Radio System 10 base station 11,21 CPU 12,22 ROM 13,23 RAM 14,24 Wireless communication module 15 Wired communication module 20 Terminals 25 Display 26 Storage 30 Servers 110,210 LLC Processing Unit 120,220 Link Management Department 121,221 Data Processing Unit 122 Beacon Management Department 123,223 Management Department 124,224 MAC frame processing section 130,140,150,230,240,250 Wireless signal processing unit 260 Application Execution Unit

Claims

1. a first radio signal processing unit configured to be able to transmit and receive radio signals using a first channel; a second radio signal processing unit configured to be able to transmit and receive radio signals using a second channel different from the first channel; a beacon management unit that manages transmission of a beacon from the first wireless signal processing unit so that a first beacon is periodically transmitted from the first wireless signal processing unit, and manages transmission of a beacon from the second wireless signal processing unit so that the first beacon and a second beacon including information that is simpler than information included in the first beacon are periodically switched and transmitted from the second wireless signal processing unit; A base station comprising:

2. The beacon management unit further manages transmission of the beacon from the first wireless signal processing unit so that the first beacon and the second beacon are periodically transmitted from the first wireless signal processing unit, a transmission frequency of the first beacon transmitted from the first wireless signal processing unit is higher than a transmission frequency of the first beacon transmitted from the second wireless signal processing unit; The base station according to claim 1 .

3. The beacon management unit further manages transmission of the beacon from the first wireless signal processing unit so that the first beacon and the second beacon are periodically transmitted from the first wireless signal processing unit, a transmission timing of the first beacon by the first radio signal processing unit and a transmission timing of the first beacon by the second radio signal processing unit are shifted from each other; The base station according to claim 1 .

4. The first beacon includes information necessary for establishing a multi-link using the first radio signal processing unit and the second radio signal processing unit. A base station according to any one of claims 1 to 3.

5. The second beacon is an S1G beacon or a beacon transmitted in a FILS system. A base station according to any one of claims 1 to 4.

6. The first channel is a channel used for establishing a multi-link using the first radio signal processing unit and the second radio signal processing unit. A base station according to any one of claims 1 to 5.

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