Communication apparatus, communication method, and storage medium

Abstract

The invention discloses a communication apparatus, a communication method, and a storage medium. A link is established between communication devices 102 and 103 capable of performing multi-link communications conforming to an Institute of Electrical and Electronic Engineers (IEEE) 802.11 series standard via a frequency channel, and a media access control (MAC) frame is transmitted between the communication devices 102 and 103, in which the communication devices 102 and 103 are configured to communicate with each other via a frequency channel. The information about a second link, which is different from the established first link, is included after a field in which information about a service set identifier (SSID) is stored.

Description

[0001] This application is a divisional application of an invention patent application with an application date of February 8, 2021, an application number of 202180018461.X (international application number is PCT / JP2021 / 004554), and an invention name of “Communication device, communication method, and storage medium”. Technical Field

[0002] The present invention relates to the transmission and reception of information concerning communications in wireless communications. Background Art

[0003] As a wireless local area network (WLAN) communication standard established by the Institute of Electrical and Electronics Engineers (IEEE), the IEEE 802.11 series of standards are known. The IEEE 802.11 series of standards include standards such as the IEEE 802.11a / b / g / n / ac / ax standards.

[0004] In order to further increase throughput and enhance frequency usage efficiency, the IEEE 802.11be standard has been considered as a new IEEE 802.11 series standard. In the IEEE 802.11be standard, multi-link communication has been considered in which an access point (AP) establishes multiple links with a station (STA) via multiple different frequency channels and communicates with the STA.

[0005] Patent Document 1 discusses establishing a link in a case where an AP and a STA perform communication.

[0006] Citation List

[0007] Patent Literature

[0008] Patent Document 1: Japanese Unexamined Patent Application Publication No. 2012-523202 Summary of the invention

[0009] Technical issues

[0010] In multi-link communication, for example, it is considered to preferentially use a relatively uncongested link among multiple links to perform communication. In order to perform such control, the AP and the STA are required to transmit information about another link. However, since multi-link communication is a technology newly introduced in the IEEE 802.11 series of standards, when transmitting information about another link using, for example, a media access control (MAC) frame, its compatibility needs to be considered.

[0011] In view of the foregoing, the present invention is directed to ensuring compatibility of frames in the case of transmitting information on a link to be established with other communication devices in a frequency channel conforming to the IEEE 802.11 series of standards.

[0012] Solution to the problem

[0013] In order to achieve the above-mentioned purpose, according to one aspect of the present invention, a communication device capable of performing multi-link communication in accordance with the Institute of Electrical and Electronics Engineers (IEEE) 802.11 series standards, the communication device comprising: an establishment unit, the establishment unit being configured to establish links with other communication devices via a frequency channel; and a communication unit, the communication unit being configured to transmit a media access control (MAC) frame, in which information about a second link with the other communication device is included after a field in which information about a service set identifier (SSID) is stored, and the second link with the other communication device is different from the first link established by the establishment unit.

[0014] Advantageous Effects of the Invention

[0015] According to the present invention, by appropriately transmitting information on a link to be established with other communication devices in a frequency channel conforming to the IEEE 802.11 series standards, it becomes possible to ensure compatibility of frames. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] [ Figure 1 ] Figure 1 is a diagram illustrating a configuration of a network to which the communication device 102 belongs.

[0017] [ Figure 2 ] Figure 2 is a diagram illustrating the hardware configuration of the communication device 102 .

[0018] [ Figure 3 ] Figure 3 is a diagram illustrating a functional configuration of the communication device 102

[0019] [ Figure 4 ] Figure 4 1 is a sequence diagram illustrating an example of processing to be performed when the communication devices 102 and 103 establish a link of multi-link communication.

[0020] [ Figure 5 ] Figure 5 is a diagram illustrating an example of a frame format of a multi-link capability element.

[0021] [ Figure 6 ] Figure 6 is a flowchart illustrating processing to be performed by the communication device 103 when performing multi-link communication.

[0022] [ Figure 7 ] Figure 7 is a flowchart illustrating processing to be performed by the communication device 102 when performing multi-link communication.

[0023] [ Figure 8 ] Figure 8 is a diagram illustrating information included in a beacon.

[0024] [ Fig. 9 ] Fig. 9 is a diagram illustrating information included in a probe response.

[0025] [ Fig.10 ] Fig.10 is a diagram illustrating an example of a frame format of a switching destination link information element (information element). DETAILED DESCRIPTION

[0026] Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. In addition, the configurations to be described in the following exemplary embodiments are merely examples, and the present invention is not limited to the configurations shown in the accompanying drawings.

[0027] Figure 1 The diagram illustrates the configuration of a network in which the communication device 102 according to the present exemplary embodiment participates. The communication device 102 is an access point (AP) having a role of constructing the network 101. The network 101 is a wireless network. In the present exemplary embodiment, in the case where the communication device 102 constructs a plurality of networks, the basic service set identifiers (BSSIDs) of the respective networks are different. The BSSID is an identifier for identifying a network. In addition, the communication device 102 indicates a common service set identifier (SSID) shared between all networks. Alternatively, the communication device 102 may use a different SSID for each network. The SSID is an identifier for identifying an AP.

[0028] The communication device 103 is a station (STA) having a role of participating in the network 101. Each communication device complies with the Institute of Electrical and Electronics Engineers (IEEE) 802.11be (Extremely High Throughput (EHT)) standard, and can perform wireless communication that complies with the IEEE 802.11be standard via the network 101. EHT can be interpreted as an abbreviation for extremely high throughput. Each communication device can perform communication in a frequency band including a 2.4 gigahertz (GHz) band, a 5 GHz band, and a 6 GHz band. The frequency band to be used by each communication device is not limited to these, and, for example, different frequency bands such as a 60 GHz band can be used. In addition, each communication device can perform communication using a bandwidth including a 20 megahertz (MHz) bandwidth, a 40 MHz bandwidth, an 80 MHz bandwidth, a 160 MHz bandwidth, and a 320 MHz bandwidth.

[0029] By performing orthogonal frequency division multiple access (OFDMA) communication conforming to the IEEE 802.11be standard, the communication devices 102 and 103 can realize multi-user (MU) communication in which signals of multiple users are multiplexed. In OFDMA communication, a portion of the divided frequency band (resource unit (RU)) is allocated to each STA while avoiding redundancy, and the carriers allocated to the respective STAs are orthogonal to each other. The AP can therefore communicate with multiple STAs concurrently.

[0030] In addition, the communication devices 102 and 103 perform multi-link communication by establishing a link via multiple frequency channels to perform communication. A frequency channel is a frequency channel defined in the IEEE 802.11 series of standards, and refers to a frequency channel that can perform wireless communication that complies with the IEEE 802.11 series of standards. In the IEEE 802.11 series of standards, multiple frequency channels are defined for each frequency band in the 2.4 GHz band, the 5 GHz band, and the 6 GHz band. In the IEEE 802.11 series of standards, the bandwidth of each frequency channel is defined as 20 MHz. By joining with adjacent frequency channels, a bandwidth of 40 MHz or more can be used in one frequency channel. For example, the communication device 102 can establish a first link 104 with the communication device 103 via a first frequency channel in the 2.4 GHz band and establish a second link 105 with the communication device 103 via a second frequency channel in the 5 GHz band, and communicate with the communication device 103 via these two links. In this case, the communication device 102 concurrently maintains a second link 105 via a second frequency channel with the first link 104 via the first frequency channel. In this way, the communication device 102 can increase the throughput of the communication with the communication device 103 by establishing a link with the communication device 103 via multiple frequency channels. The communication devices 102 and 103 can establish multiple links via different frequency bands in multi-link communication. For example, in addition to the first link 104 in the 2.4 GHz band and the second link 105 in the 5 GHz band, the communication devices 102 and 103 can also establish a third link in the 6 GHz band. Alternatively, the communication devices 102 and 103 can establish a link via multiple different channels included in the same frequency band. For example, the communication devices 102 and 103 can establish a first link 104 via 1 channel (ch) in the 2.4 GHz band and establish a second link 105 via 5ch in the 2.4 GHz band. In addition, the links in the same frequency band and the links in different frequency bands can exist in a mixed manner. For example, in addition to establishing the first link 104 via 1ch in the 2.4GHz band and establishing the second link 105 via 5ch in the 2.4GHz band, the communication devices 102 and 103 may establish a third link via 36ch in the 5GHz band. By establishing multiple connections with the communication device 103 in different frequency bands, even if a certain frequency band is crowded, the communication device 102 can communicate with the communication device 103 in another frequency band. Therefore, a decrease in the throughput of communication with the communication device 103 can be prevented.

[0031] In this way, in multi-link communication, it is sufficient that at least the frequency channels of the multiple links established by the communication devices 102 and 103 are different. In multi-link communication, it is only required that the channel spacing between the frequency channels of the multiple links established by the communication devices 102 and 103 is greater than at least 20 MHz. In the present exemplary embodiment, the communication devices 102 and 103 establish the first link 104 and the second link 105, but three or more links may be established.

[0032] The communication devices 102 and 103 can perform three modes of communication as multi-link communication. One of the three modes is an asynchronous mode (Async Mode). In this mode, the communication via the link in the multi-link communication is performed asynchronously. Specifically, the communication via the first link and the communication via the second link are performed at each independent timing. Therefore, the communication via the first link and the second link can be performed at a timing independent of the timing of performing the communication via another link. In this case, if the channel interval between the frequency channels (channels) used by each link is narrow, the communication via one link affects the communication via another link. Specifically, if the frequency channels of the links are close, because the communication performed via one link is detected by another link through carrier sensing, when the communication is being performed via one link, the communication via another link becomes unexecutable. Therefore, under Async Mode, the channel interval between the links becomes wider. Another mode is a synchronous mode (Sync Mode). In this mode, the communication via multiple links is performed synchronously. Specifically, the communication via the first link and the communication via the second link start at the same timing. In this case, because the communication via each link starts at the same time, the communication performed via one link is not detected by another link through carrier sensing. Therefore, the channel spacing between the channels used by each link can be narrow. In addition, another mode is a semi-async mode (Semi-Async Mode). In this mode, in the case of performing data communication via a certain link, the communication via the two links is synchronously performed when the frequency channel of the other link is not occupied. For example, in the case where the backoff counter of the first link becomes 0, in the case where the frequency channel of the second link is not occupied, the communication via the first link and the second link starts at the same timing. In this case, the backoff counter of the second link does not need to be 0. In the case where the backoff counter of the first link becomes 0, in the case where the frequency channel of the second link is occupied, only the communication via the first link starts, and the communication via the second link does not start. In this mode, in the case of concurrently performing communication via multiple links, because the communication via each link starts simultaneously, the interval between the channels used by each link can be narrow. Communication devices 102 and 103 can select the mode to be used in multi-link communication based on the channel spacing between multiple established links.

[0033] In the case of performing multi-link communication, at least one of the communication devices 102 and 103 is a device that can simultaneously perform data transmission via a certain link and data reception via different links. Alternatively, at least one of the communication devices 102 and 103 may be a device that can only simultaneously perform data transmission via different links when performing data transmission via a certain link. Alternatively, at least one of the communication devices 102 and 103 may be a device that can only simultaneously perform data reception via different links when performing data reception via a certain link. Alternatively, at least one of the communication devices 102 and 103 may be a device that can simultaneously maintain multiple links but cannot simultaneously perform data communication via different links when performing data communication via a certain link. Such a communication device does not support Sync Mode or Semi-Async Mode.

[0034] In the case of performing multi-link communication, the communication devices 102 and 103 divide a piece of data and send the divided data to the other party's device via multiple links. Alternatively, by sending the same data via multiple links, the communication devices 102 and 103 can perform communication via one link as a backup communication for communication via another link. Specifically, it is considered that the communication device 102 sends the same data to the communication device 103 via the first link via the first frequency channel and the second link via the second frequency channel. In this case, for example, even if an error occurs in the communication via the first link, the same data is sent via the second link. The communication device 103 can therefore receive the data sent from the communication device 102. Alternatively, the communication devices 102 and 103 can switch the link to be used depending on the type of frame to be transmitted or the type of data to be transmitted. For example, the communication device 102 can send a management frame via the first link and send a data frame including data via the second link. The management frame specifically refers to a beacon frame, a probe request frame / response frame or an association request frame / response frame. In addition to these frames, a disassociation frame, an authentication frame, a deauthentication frame, and an action frame are also referred to as a management frame. A beacon frame is a frame that reports information about a network. In addition, a probe request frame is a frame that requests network information. A probe response frame is a response to a probe request frame, and is a frame that provides network information. An association request frame is a frame that requests a connection. An association response frame is a response to an association request frame, and is a frame that indicates connection permission or an error. A disassociation frame is a frame that disconnects. An authentication frame is a frame that authenticates the other device, and a disauthentication frame is a frame that stops the authentication of the other device and disconnects. An action frame is a frame that performs additional functions other than the above functions. Communication devices 102 and 103 send and receive management frames that comply with the IEEE 802.11 series of standards. Alternatively, in the case where, for example, the communication device 102 sends data about a captured image, the communication device 102 may send meta information (metainformation) such as date, parameters (aperture value, shutter speed, etc.) set at the time of image capture, and position information via a first link, and send pixel information via a second link.

[0035] The communication devices 102 and 103 may be capable of performing multiple-input multiple-output (MIMO) communication. In this case, the communication devices 102 and 103 include multiple antennas, and one party uses the same frequency channel to send different signals from the antennas. The receiving side uses multiple antennas to simultaneously receive all signals that have arrived from multiple streams, separate the signals from the streams, and decode the signals. In this way, by performing MIMO communication, the communication devices 102 and 103 can transmit a larger amount of data during the same time period compared to the case where MIMO communication is not performed. In addition, in the case of performing multi-link communication, the communication devices 102 and 103 can perform MIMO communication via a portion of the link.

[0036] In the present exemplary embodiment, in the case where the communication device 102 performs multi-link communication with the communication device 103, the communication device 102 can send information about the second link 105 to the communication device 103 via the first link 104. The information about the second link 105 is, for example, information indicating the frequency channel used by the second link 105, and information indicating whether the frequency channel is busy (occupied). The communication device 103 that has received the information about the second link 105 can use the received information to determine whether to switch the link to be used for data communication with the communication device 102 from the first link 104 to the second link 105. In this way, by receiving information about different links established with the communication device 102, the communication device 103 can switch the link to be used for data communication to a more appropriate link. In the present exemplary embodiment, such information about the second link 105 will be referred to as the switching destination information of the multi-link communication. Reference will be made to the switching destination information to be described below. Fig.10 Describes the details of the switching destination information.

[0037] Instead of or in addition to the information about the link that has been established with the communication device 103, the communication device 102 may send information about the link that it can establish with the communication device 103. The information about the link that can be established with the communication device 103 is, for example, information indicating a frequency channel through which the communication device 102 has established a wireless network but has not yet established a link with the communication device 103. Instead of or in addition to this, the information may be information indicating whether the frequency channel is busy. In the present exemplary embodiment, in addition to or in addition to the information about the second link 105, these multiple pieces of information may be referred to as switching destination information for multi-link communication. Reference will be made to the following description of the switching destination information. Fig.10 The details of these multiple pieces of information are described. By receiving such information, the communication device 103 can newly establish a link with the communication device 102, and switch the link to be used for data communication from the currently used link to the newly established link. In this way, by newly establishing a link serving as a switching destination, the power saving of the communication devices 102 and 103 at the time of link switching can be improved.

[0038] The communication devices 102 and 103 comply with the IEEE 802.11be standard, but the communication devices 102 and 103 may additionally comply with at least any one of the old standards that are standards established earlier than the IEEE 802.11be standard. The old standard refers to the IEEE 802.11a / b / g / n / ac / ax standard. In this exemplary embodiment, at least any one of the IEEE 802.11a / b / g / n / ac / ax / be standards will be referred to as the IEEE 802.11 series of standards. In addition to the IEEE 802.11 series of standards, the communication devices 102 and 103 may also comply with other communication standards such as Bluetooth (registered trademark), near field communication (NFC), ultra-wideband (UWB), ZigBee, and multi-band OFDM alliance (MBOA). UWB includes wireless universal serial bus (USB), wireless 1394, Winners information network (WiNET), etc. Furthermore, the communication devices 102 and 103 may conform to a communication standard for wired communication such as a wired local area network (LAN).

[0039] Specific examples of the communication device 102 include a wireless LAN router, a personal computer (PC), and the like, but the communication device 102 is not limited to these. The communication device 102 may be any communication device as long as the communication device can perform multi-link communication with other communication devices. In addition, the communication device 102 may be an information processing device such as a wireless chip that can perform wireless communication compliant with the IEEE 802.11be standard. In addition, specific examples of the communication device 103 include a camera, a tablet computer, a smart phone, a PC, a mobile phone, a camcorder, and the like, but the communication device 103 is not limited to these. It is only required that the communication device 103 is a communication device that can perform multi-link communication with other communication devices. In addition, the communication device 103 may be an information processing device such as a wireless chip that can perform wireless communication compliant with the IEEE 802.11be standard. In addition, Figure 1 The network shown in is a network including one AP and one STA, but the number of APs and the number of STAs are not limited to these. In addition, the information processing device such as a wireless chip includes an antenna for transmitting the generated signal.

[0040] In the present exemplary embodiment, the communication device 102 is used as an AP and the communication device 103 is used as an STA, but the configuration is not limited thereto. Both the communication devices 102 and 103 can be used as STAs. In this case, the communication device 102 is a STA, but operates as a device having a role of building a wireless network for establishing a link with the communication device 103.

[0041] Figure 2The hardware configuration of the communication device 102 according to the present exemplary embodiment is illustrated. The communication device 102 includes a storage unit 201 , a control unit 202 , a function unit 203 , an input unit 204 , an output unit 205 , a communication unit 206 , and an antenna 207 .

[0042] The storage unit 201 includes one or more memories such as a read-only memory (ROM) and a random access memory (RAM), and stores computer programs for performing various operations to be described below, and various types of information such as communication parameters for wireless communication. In addition to memories such as ROM and RAM, a storage medium such as a floppy disk, a hard disk, an optical disk, a magneto-optical disk, a compact disk read-only memory (CD-ROM), a recordable CD (CD-R), a magnetic tape, a nonvolatile memory card, or a digital versatile disk (DVD) can be used as the storage unit 201. In addition, the storage unit 201 may include a plurality of memories, etc.

[0043] For example, the control unit 202 includes, for example, one or more processors, such as a central processing unit (CPU) and a microprocessing unit (MPU). By executing a computer program stored in the storage unit 201, the control unit 202 controls the entire communication device 102. The control unit 202 can control the entire communication device 102 in cooperation with the computer program stored in the storage unit 201 and the operating system (OS). In addition, the control unit 202 generates data and signals (radio frames) to be sent in communication with other communication devices. In addition, the control unit 202 may include multiple processors such as a multi-core processor, and control the entire communication device 102 using the multiple processors.

[0044] Furthermore, the control unit 202 executes predetermined processing such as wireless communication, image capturing, printing, and projection by controlling the function unit 203. The function unit 203 is hardware for the communication device 102 to execute predetermined processing.

[0045] The input unit 204 receives various operations from the user. The output unit 205 performs various outputs to the user via the monitor screen and the speaker. The output performed by the output unit 205 can be a display on the monitor screen, a voice output of the speaker, a vibration output, etc. Both the input unit 204 and the output unit 205 can be implemented by one module (such as a touch panel). In addition, the input unit 204 and the output unit 205 can each be formed integrally with the communication device 102, or can each be formed separately from the communication device 102.

[0046] The communication unit 206 controls wireless communication that complies with the IEEE 802.11be standard. In addition, the communication unit 206 can control wireless communication that complies with other IEEE 802.11 series standards in addition to the IEEE 802.11be standard, and can control wired communication via a wired LAN or the like. The communication unit 206 controls the antenna 207, and sends and receives signals of wireless communication that have been generated by the control unit 202. In the case where the communication device 102 complies with the NFC standard, the Bluetooth standard, etc. in addition to the IEEE 802.11be standard, the communication unit 206 can control wireless communication that complies with these communication standards. In addition, in the case where the communication device 102 can perform wireless communication that complies with multiple communication standards, the communication unit and antenna corresponding to each communication standard can be separately included. Via the communication unit 206, the communication device 102 transmits data such as image data, document data, and video data with the communication device 103. In addition, the antenna 207 can be formed separately from the communication unit 206, or can be formed as one module together with the communication unit 206.

[0047] Antenna 207 is an antenna that can perform communication in the 2.4 GHz band, the 5 GHz band, and the 6 GHz band. In the present exemplary embodiment, communication device 102 includes one antenna, but may include different antennas for each frequency band. In the case where communication device 102 includes a plurality of antennas, communication device 102 may include communication units 206 corresponding to the respective antennas.

[0048] The communication device 103 has a hardware configuration similar to that of the communication device 102 .

[0049] Figure 3 The functional configuration of the communication device 102 according to the present exemplary embodiment is illustrated. The communication device 102 includes a capability information generation unit 301 for multi-link communication, an operation information determination unit 302 for multi-link communication, and a switching destination information generation unit 307 for multi-link communication. In addition to these, the communication device 102 also includes a connection processing unit 304, a media access control (MAC) frame generation unit 305, and a data transmission / reception unit 306.

[0050] The capability information generation unit 301 is a block that generates capability information about multi-link communication of the communication device 102. The communication device 102 generates capability information for notifying different communication devices about its own multi-link communication capability. Figure 5 Capability information about multi-link communication is described. As for capability information, a communication device may notify a different communication device of its own capability information, or may only receive capability information of a counterpart device from a different communication device.

[0051] The operation information determination unit 302 determines a block of operation information about multilink communication with a counterpart device based on capability information about multilink communication of itself and the counterpart device. The operation information about multilink communication refers to a frequency channel and a bandwidth to be used in communication performed as multilink communication between the communication devices 102 and 103. Figure 5 Describes the details of the operation information about the multi-link communication. As for the operation information, the determined operation information may be notified to the counterpart device, or the determined operation information does not need to be notified to the counterpart device.

[0052] The connection processing unit 304 is a block that performs processing for causing the communication device 103 serving as an STA to participate in the network 101 constructed by the communication device 102. Specifically, the connection processing unit 304 causes the communication device 102 to transmit an association response frame as a response to an association request that is a connection request received from the communication device 103. The communication device 102 includes the connection processing units 304 corresponding to a plurality of respective links that it itself is to establish.

[0053] The MAC frame generation unit 305 is a block that generates a MAC frame including information indicating capability information about multi-link communication that has been generated by the capability information generation unit 301, and operation information about multi-link communication that has been determined by the operation information determination unit 302. The MAC frame generation unit 305 also generates a MAC frame including information indicating switching destination information about multi-link communication that has been generated by the switching destination information generation unit 307 to be described below. The MAC frame generated by the MAC frame generation unit 305 is included in at least any one of a beacon, a probe response, and an association response for transmission. In addition to this or in lieu thereof, the generated MAC frame is included in a reassociation response for transmission. The capability information and operation information included in the MAC frame generated by the MAC frame generation unit 305 are determined by the radio frames to be described below. Figure 5 In addition, the switching destination information included in the MAC frame generated by the MAC frame generation unit 305 is indicated by the elements shown in Fig.10 The elements shown in the instructions.

[0054] The data transmission / reception unit 306 is a block that transmits and receives data frames in the multi-link communication based on the operation information about the multi-link communication that has been determined by the operation information determination unit 302. The data transmission / reception unit 306 can transmit a radio frame including a MAC frame generated by the MAC frame generation unit 305, and receive a radio frame from a counterpart device.

[0055] The switching destination information generating unit 307 is a block that generates information about different links in multi-link communication, which is to be transmitted by the communication device 102 to the communication device 103. The communication device 102 generates information about a link that has been established by itself with the communication device 103 and that is different from the link to be used for transmission of information. Fig.10 Information about different links is described. As the information about different links, information about links that can be established with the communication device 103 from now on can be generated. The information about the links that can be established with the communication device 103 from now on is information about links that have not been used for establishment of a link with the communication device 103 but can be established via the wireless network constructed by the communication device 102. In addition to the information about different links, information about links to be used for transmission of information can also be generated as information to be transmitted to the communication device 103.

[0056] The communication device 103 has a functional configuration similar to that of the communication device 102 , but differs in the following point.

[0057] The communication device 103 includes a request information determination unit 302 instead of the operation information determination unit 302. The request information determination unit 302 is a block that determines request information about multilink communication with the counterpart device based on the capability information about multilink communication of the communication device 103 and the counterpart device. The request information about multilink communication refers to a request for a frequency channel and a bandwidth to be used in the communication to be performed as the multilink communication between the communication devices 102 and 103. Reference will be made to the following description. Figure 5 Describes the details of the request information about the multilink communication. The communication device 103 may notify the counterpart device of the determined request information, or does not need to notify the counterpart device of the determined request information.

[0058] The connection processing unit 304 is a block that performs processing for the communication device 103 to participate in the network 101 constructed by the communication device 102 serving as an AP. Specifically, the connection processing unit 304 causes the communication device 103 to send an association request as a connection request to the communication device 102, and receives an association response from the communication device 102 as a response.

[0059] The MAC frame generation unit 305 is a block that generates a MAC frame including information indicating capability information about multi-link communication that has been generated by the capability information generation unit 301 and request information about multi-link communication that has been determined by the request information determination unit 302. The MAC frame generated by the MAC frame generation unit 305 is included in at least any one of the radio frames of the probe request, the association request, and the re-association request for transmission. The capability information and request information included in the MAC frame generated by the MAC frame generation unit 305 are determined by the following. Figure 5 The elements shown in the instructions.

[0060] The communication device 103 does not need to include the switching destination information generating unit 307 .

[0061] Figure 4 1 is a sequence diagram illustrating an example of processing to be performed when the communication devices 102 and 103 establish a link of multi-link communication.

[0062] The communication devices 102 and 103 each include a connection processing unit 304 corresponding to a plurality of corresponding links inside. AP1 of the communication device 102 is a connection processing unit 304 for a first link, and AP2 is a connection processing unit 304 for a second link. In addition, STA1 of the communication device 103 is a connection processing unit 304 for a first link, and STA2 is a connection processing unit 304 for a second link. STA1 and AP1 perform a process of communication via a first frequency channel (e.g., 1ch in a 2.4GHz band). STA2 and AP2 perform a process of communication via a second frequency channel (e.g., 36ch in a 5GHz band).

[0063] The processing in this sequence starts according to the power of the communication devices 102 and 103 being turned on. Alternatively, at least one of the communication devices 102 and 103 may start the processing according to the start instruction of the multi-link communication being issued from the user or the application. Alternatively, at least one of the communication devices 102 and 103 may start the processing according to the data amount of the data desired to be transmitted with the counterpart device becoming greater than or equal to a predetermined threshold value.

[0064] If the communication device 103 receives the beacon of the communication device 102 that has been transmitted by the first frequency channel, then in step S402, the communication device 103 transmits a probe request via the first frequency channel to query network information about the communication device 102. The probe request includes the SSID of the communication device 103. By including the SSID described below in addition to the SSID Figure 5 By including the multi-link capability element shown in FIG. 1 into the detection request, the communication device 103 can notify the communication device 102 of the capability information about the multi-link communication of the communication device 103.

[0065] If the communication device 102 receives the probe request, then in step S403, the communication device 102 sends a probe response to the communication device 103 via the first frequency channel in response. Figure 5 In the case where the multi-link capability element shown in is included in the beacon, the communication device 102 includes the element in the detection response and sends it. Alternatively, the communication device 102 may only include the multi-link capability element described below. Figure 5A portion of the information included in the multi-link capability element shown in is included in the beacon, and the remaining information or all of the pieces of information are included in the probe response.

[0066] By performing the processing in steps S401 to S403, the communication devices 102 and 103 can exchange their capability information about multi-link communication. Fig.10 The switching destination information element shown in is included in the beacon to be sent in step S401, and the communication device 102 can indicate the switching destination information in the multi-link communication. In addition to the beacon or instead of the beacon, the communication device 102 can include the switching destination information element in the probe response to be sent in step S403. After establishing at least one link of the multi-link communication with the communication device 103, the communication device 102 includes the switching destination information element in at least one of the beacon and the probe response. In this case, in the case where the communication device 102 has not established any link of the multi-link communication with the communication device 103, the communication device 102 sends a beacon and a probe response that do not include the switching destination information. Alternatively, even if the communication device 102 has not established any link of the multi-link communication with the communication device 103, the communication device 102 may include the switching destination information indicating information about the link that can be established with the communication device 103.

[0067] Next, the communication device 103 sends an association request as a connection request to the communication device 102 via the first frequency channel. Figure 5 The multi-link capability element shown in is included in the association request to notify the communication device 102 about the capability information of the multi-link communication of the communication device 103. The communication device 103 can determine the capability information to be sent in step S404 based on the capability information about the multi-link communication of the communication device 102 that has been acquired in at least one of steps S401 or S403. For example, even in a case where the communication device 103 can combine links in the 2.4 GHz band and the 5 GHz band in multi-link communication, the communication device 102 is considered to support only multiple links in the 2.4 GHz band. In this case, the communication device 103 may send only the capability information about the establishment of multiple links in the 2.4 GHz band as the capability information to be sent in this step. In the present exemplary embodiment, the communication device 103 sends the capability information about its own multi-link communication in step S402, but the processing is not limited thereto. The communication device 103 may send the capability information only in this step, without sending the capability information in step S402. Alternatively, by Figure 5In the association request, the communication device 103 may send request information for making a request when performing multi-link communication, instead of capability information. The request information about the request from the communication device 103 may be Figure 5 The multilink capability element shown in , or may be indicated by another element. Figure 5 Describes the details of the request information.

[0068] If the communication device 102 receives the association request, then in step S405, the communication device 102 transmits an association response to the communication device 103 via the first frequency channel in response. The association response transmitted in this step includes a multi-link capability element indicating operation information when performing multi-link communication with the communication device 103, which has been determined by the communication device 102. The operation information may be indicated by an element other than the multi-link capability element. In the case where the communication device 103 serving as the STA has transmitted the association request including the operation information requested by the communication device 103 in step S404, the communication device 102 may transmit an association response including only the executability of the request.

[0069] In the case where the communication device 103 can perform multi-link communication based on the operation information included in the association response, in step S406, the communication devices 102 and 103 establish a link via the first frequency channel and start data communication. In this case, in the case where the operation information sent by the communication device 102 includes operation information of a link via the second frequency channel, in step S407, the communication devices 102 and 103 also establish a link via the second frequency channel and start data communication.

[0070] Also in the case where the communication device 102 permits the request information sent by the communication device 103 in step S404 in step S405, the processing in step S406 is similarly performed. In the case where the request information sent by the communication device 103 in step S404 also includes request information about the link via the second frequency channel, the processing in step S407 is performed.

[0071] In the present exemplary embodiment, two links are established through frame transmission and reception via one frequency channel, but the number of links is not limited thereto, and three or more links may be established.

[0072] In the present exemplary embodiment, a case has been described where multi-link communication is started from a state where no link has been established between the communication devices 102 and 103, but the configuration is not limited thereto. The communication devices 102 and 103 may start multi-link communication by establishing a new link in addition to the already established links. In this case, in a case where the communication device 103 serving as a STA has acquired capability information about multi-link communication of the communication device 102 serving as an AP, the sequence may be started from the processing in step S404. Alternatively, in a case where the communication device 102 has acquired capability information about multi-link communication of the communication device 103, the communication device 102 may be enabled to start the sequence from the processing in step S404 by sending a signal for causing the communication device 103 to send an association request. Alternatively, the communication devices 102 and 103 may newly establish a link in addition to a plurality of already established links. Also in this case, Figure 4 The sequence shown in may start from the processing in step S404.

[0073] The communication device 102 transmits a beacon at predetermined intervals. Based on the switching destination information included in the beacon transmitted at predetermined intervals, the communication device 103 can determine whether to switch a link to be used to perform data communication with the communication device 102 from a currently used link to a different link. The communication device 102 transmits a probe response as a response to the probe request transmitted from the communication device 103. The communication device 103 can transmit a probe request to the communication device 102 for the purpose of not only inquiring about the network information about the communication device 102 but also acquiring the switching destination information.

[0074] Figure 5 is a diagram illustrating an example of a frame format of a multi-link capability element. In this exemplary embodiment, Figure 5 The name of the element shown in is a multilink capability element, but the name is not limited thereto. For example, the name may be a different name such as a multilink element.

[0075] By using Figure 5 , the communication devices 102 and 103 can notify the other device of capability information indicating its own capability in multi-link communication. Figure 5 In addition to or in place of the capability information, the communication device 102 may also notify the counterpart device of operation information when performing multi-link communication. Figure 5 In addition to or instead of the capability information, the communication device 103 may also notify the counterpart device of request information when performing multi-link communication.

[0076] Figure 5The multilink capability element shown in FIG. 5 includes an element ID 501, a length 502, and a multilink (ML) capability 503. The element ID 501 is an identifier for identifying an information element. In the present exemplary embodiment, an identifier indicating a multilink capability element is included. The length 502 is a field indicating the data length of the element. In the present exemplary embodiment, information indicating the data length of the ML capability 503 is included. The ML capability 503 indicates information unique to the multilink capability element and includes information about multilink communication. Details of the information included in the ML capability 503 will be described below.

[0077] The communication devices 102 and 103 generate sequentially from the element ID 501 Figure 5 , and sends the generated multilink capability element to different communication devices. In this case, the communication devices 102 and 103 send the multilink capability element after generating all the fields in the frame. Specifically, the communication devices 102 and 103 send the multilink capability element to different communication devices after generating all the element IDs 501, lengths 502, and ML capabilities 503. Alternatively, the communication devices 102 and 103 may perform the transmission concurrently with the generation of the fields. Specifically, for example, the communication devices 102 and 103 may perform the generation of the length 502 concurrently with the transmission of the generated element ID 501.

[0078] The communication device 102 used as an AP adds a MAC frame including a multi-link capability element to a radio frame such as a beacon or a probe response, and transmits the radio frame. In addition to these radio frames, the communication device 102 may also add a MAC frame including this element to a radio frame such as an association response or a reassociation response. The communication device 103 used as a STA adds a MAC frame including a multi-link capability element to a radio frame such as a probe request or an association request, and transmits the radio frame. In addition to these radio frames, the communication device 103 may also add a MAC frame including this element to a reassociation request.

[0079] The ML capability 503 includes common information 511, per-band information 512, and per-link information 513. Common information 511 is a field indicating information common to all frequency bands and links. Per-band information 512 is a field indicating information common to all links included in a specific frequency band, and is information indicated for each frequency band. Per-link information 513 is a field indicating information for each link.

[0080] Common information 511 includes primary CH 521, synchronous mode support 522, asynchronous mode support 523, and semi-asynchronous mode support 528. Common information 511 also includes total maximum link number 524, band combination information 525, and per-band information number 526. Common information 511 also includes per-link information number 527 and device type 529.

[0081] The main CH 521 is a field including information indicating a frequency channel, via which transmission and reception of management frames regarding multi-link communication are performed. The main CH refers to a frequency channel to be used when transmission and reception of management frames are performed when connection or disconnection of a link is performed in multi-link communication. Specifically, the main CH includes information indicating a frequency channel, via which transmission and reception of a beacon including a multi-link capability element are performed. The communication device 102 serving as an AP includes, into the main CH, information indicating a frequency channel to be used when a beacon including a multi-link capability element is transmitted. The communication device 103 serving as an STA includes, into the main CH, information indicating a frequency channel, by which a beacon including a multi-link capability element has been received (i.e., a detection request including the element is transmitted). In this exemplary embodiment, information indicating a first frequency channel is included, Figure 4 In the sequence shown in , the transmission and reception of beacons and probe requests / responses are performed via the first frequency channel. In the case where the frequency channel to be used to perform transmission and reception of management frames is changed after the communication devices 102 and 103 start multi-link communication, the main CH 521 includes information indicating the changed frequency channel. The main CH 521 includes information indicating a frequency channel (transmission and reception of management frames are performed via the frequency channel), regardless of which of the capability information, operation information, or request information is indicated by the element.

[0082] The synchronization mode support 522 is a field including capability information indicating whether the communication device 102 or 103 that sends the element supports the synchronization mode of multi-link communication. For example, in the case where this field includes 0, this field indicates that the sending device of the element does not support the synchronization mode, and in the case where this field includes 1, this field indicates that the sending device supports the synchronization mode.

[0083] In the case where the multi-link capability element indicates operation information, the synchronization mode support 522 may indicate whether the synchronization mode of the multi-link communication is to be performed. For example, in the case where the communication device 102 sends an association response including this element, this field indicates whether the synchronization mode is to be performed in the communication of the link to be established through the exchange of this association. In this case, for example, in the case where this field includes 0, this field indicates that the multi-link communication in the synchronization mode will not be performed, and in the case where this field includes 1, this field indicates that the multi-link communication in the synchronization mode is to be performed.

[0084] Alternatively, in the case where the multilink capability element indicates request information, the synchronization mode support 522 may indicate whether to request the execution of the synchronization mode of the multilink communication. For example, in the case where the communication device 103 serving as an STA sends an association request including this element, this field indicates whether the communication device 103 requests the execution of the synchronization mode in the multilink communication. For example, in the case where this field includes 0, this field indicates that the execution of the multilink communication in the synchronization mode is not requested, and in the case where this field includes 1, this field indicates that the execution of the multilink communication in the synchronization mode is requested.

[0085] Asynchronous mode support 523 is a field including capability information indicating whether the communication device 102 or 103 transmitting the element supports the asynchronous mode of multi-link communication. For example, in the case where this field includes 0, this field indicates that the transmitting device of the element does not support the asynchronous mode, and in the case where this field includes 1, this field indicates that the transmitting device supports the asynchronous mode.

[0086] In the case where the multilink capability element indicates operation information, the asynchronous mode support 523 can indicate whether the asynchronous mode of the multilink communication is to be performed. For example, in the case where the communication device 102 sends an association response including this element, this field indicates whether the asynchronous mode is to be performed via the link to be established through the exchange of this association. In this case, for example, in the case where this field includes 0, this field indicates that the multilink communication in the asynchronous mode will not be performed, and in the case where this field includes 1, this field indicates that the multilink communication in the asynchronous mode is to be performed. In the case where this element indicates operation information, in the case where the above-mentioned synchronous mode support 522 indicates that the synchronous mode is to be performed, this field indicates that the asynchronous mode will not be performed. Similarly, in the case where the synchronous mode support 522 indicates that the synchronous mode is not to be performed, the asynchronous mode support 523 indicates that the asynchronous mode is to be performed.

[0087] Alternatively, in the case where the multilink capability element indicates request information, the asynchronous mode support 523 may indicate whether to request the execution of the asynchronous mode of the multilink communication. For example, in the case where the communication device 103 serving as an STA sends an association request including this element, this field indicates whether the communication device 103 requests the execution of the asynchronous mode in the multilink communication. For example, in the case where this field includes 0, this field indicates that the execution of the multilink communication in the asynchronous mode is not requested, and in the case where this field includes 1, this field indicates that the execution of the multilink communication in the asynchronous mode is requested.

[0088] The semi-asynchronous mode support 528 is a field including capability information indicating whether the communication device 102 or 103 transmitting the element supports the semi-asynchronous mode of multi-link communication. For example, in the case where this field includes 0, this field indicates that the transmitting device of the element does not support the semi-asynchronous mode, and in the case where this field includes 1, this field indicates that the transmitting device supports the semi-asynchronous mode.

[0089] In the case where the multilink capability element indicates operation information, this field may indicate whether a semi-asynchronous mode of multilink communication is to be performed. For example, in the case where the communication device 102 sends an association response, this field indicates whether a semi-asynchronous mode is to be performed in the communication of the link to be established via the exchange of this association. For example, in the case where this field includes 0, this field indicates that multilink communication in the semi-asynchronous mode will not be performed. In addition, for example, in the case where this field includes 1, this field indicates that multilink communication in the semi-asynchronous mode is to be performed.

[0090] Alternatively, in the case where the multilink capability element indicates request information, this field may indicate whether to request execution of the semi-asynchronous mode of the multilink communication. For example, in the case where the communication device 103 serving as an STA sends an association request, this field indicates whether the communication device 103 requests execution of the semi-asynchronous mode in the multilink communication. For example, in the case where this field includes 0, this field indicates that execution of the multilink communication in the semi-asynchronous mode is not requested. In addition, for example, in the case where this field includes 1, this field indicates that execution of the multilink communication in the semi-asynchronous mode is requested.

[0091] In the case where which mode among the synchronous mode, asynchronous mode and semi-asynchronous mode is to be used when the communication devices 102 and 103 perform multi-link communication is preset, these fields can be omitted. Specifically, the synchronous mode support 522, the asynchronous mode support 523 and the semi-asynchronous mode support 528 can be omitted.

[0092] The total maximum number of links 524 is a field including capability information indicating the maximum number of links supported by the communication device 102 or 103 that sends the element in multi-link communication. The maximum number of links is the maximum value of the number of links that the sending device of the element can establish with one counterpart device. For example, in the case where this field includes 3 as a value, it indicates that the sending device of the element can establish up to three links for one counterpart device. In this case, concurrently with maintaining three links with one counterpart device, the sending device of the element can also maintain multiple links with another counterpart device. Alternatively, the maximum number of links can indicate the maximum value of the number of links that the sending device of the element can establish in multi-link communication, regardless of the counterpart device. In this case, for example, in the case where this field includes 3 as a value and the sending device of the element has established three links with the counterpart device, the sending device cannot establish any more links, regardless of the counterpart device. The communication device 102 used as an AP and the communication device 103 used as a STA each include information indicating the maximum value of the number of links that it can simultaneously maintain in multi-link communication into this field.

[0093] In the case where the multi-link capability element indicates operation information, this field may include the number of links to be actually established in the multi-link communication. For example, in the case where the communication device 102 serving as an AP sends an association response including this element, this field indicates the number of links to be established through the exchange of this association. Alternatively, this field may include the maximum value of the number of links that can be established in the multi-link communication with the communication device 103. In this case, the total maximum number of links 524 includes a value that is less than or equal to the smaller value of the maximum value of the number of links that can be established by its own device and the maximum value of the number of links that can be established by the counterpart device in the multi-link communication.

[0094] Alternatively, in the case where the multi-link capability element indicates request information, this field may include the number of links requested to be established in the multi-link communication. For example, in the case where the communication device 103 serving as a STA sends an association request including this element, this field indicates the number of links that the communication device 103 requests to be established by the communication device 102. Alternatively, this field may include the maximum value of the number of links that can be established in the multi-link communication with the communication device 102. In the case where the multi-link capability element indicates operation information or request information, this field may be omitted.

[0095] The band combination information 525 is a field including capability information indicating the frequency bands supported in multi-link communication by the communication device 102 or 103 that sends the element. Table 1 shows an example of the information indicated by each bit of this field. Table 1 shows the frequency bands or combinations of frequency bands to be supported for each bit. In this exemplary embodiment, when the corresponding bit includes 0, it indicates that the communication device 102 or 103 does not support multi-link communication of the content indicated by the bit, and when the corresponding bit includes 1, it indicates that the communication device 102 or 103 supports multi-link communication of the content indicated by the bit. For example, when bit 0 includes 1 in the band combination information 525 sent by the communication device 102, it indicates that the communication device 102 supports multi-link communication via different channels in the 2.4 GHz band. In addition, for example, when the value of the band combination information 525 is 0000111000, it indicates that the communication device 102 supports multi-link communication using multiple links in different frequency bands. In this case, it indicates that the communication device 102 does not support multi-link communication using multiple links in the same frequency band. In addition, by setting all bits of the band combination information 525 to 0, it can be indicated that the sending device of the multilink capability element does not support multilink communication. Alternatively, it can be indicated that the sending device of the element is currently in a state where multilink communication cannot be performed. The frequency bands supported by the communication devices 102 and 103 in the communication via only one link may be different from the frequency bands supported by the communication devices 102 and 103 in the multilink communication. For example, the communication devices 102 and 103 can support all 2.4 GHz bands, 5 GHz bands, and 6 GHz bands in the communication via only one link, and can only support 5 GHz bands and 6 GHz bands in the multilink communication. The correspondence between each bit of the band combination information 525 and the content indicated by the bit is not limited to the correspondence shown in Table 1. By increasing the number of bits of the band combination information 525, the band combination information 525 can be enabled to indicate the combination of a larger number of frequency bands or the feasibility of establishing multiple links in another frequency band.

[0096] [Table 1]

[0097]

[0098] In the case where the multi-link capability element indicates operation information, this field may indicate a frequency band to be actually used in multi-link communication. For example, in the case where the communication device 102 serving as an AP sends an association response including this element, this field includes information indicating a frequency band of a link to be established through the exchange of this association. For example, in the case where the communication devices 102 and 103 establish a link in the 2.4 GHz band and a link in the 5 GHz band, the value of the band combination information 525 becomes 00001000.

[0099] Alternatively, in the case where the multilink capability element indicates request information, this field may indicate a frequency band requested to be used in multilink communication. For example, in the case where the communication device 103 serving as an STA transmits an association request including this element, this field indicates a frequency band in which the communication device 103 requests the communication device 102 to perform multilink communication. Even in the case where this element indicates operation information or request information, this field may include capability information indicating a frequency band supported by the transmitting device of the element in multilink communication.

[0100] The number of per-band information 526 is a field including information indicating the number of pieces of per-band information included in the per-band information 512 to be described below. The per-band information 512 includes a set of per-band information for each frequency band supported in multi-link communication by the communication device 102 or 103 that transmits the multi-link capability element. Specifically, information indicating the same number of frequency bands as indicated by the band combination information 525 is included. This does not apply to the case where the common per-band information in the per-band information 512 to be described below indicates information about multiple frequency bands. In the case where the per-band information 512 to be described below is omitted, this field is also omitted.

[0101] The number of per-link information 527 is a field including information indicating the number of pieces of per-link information included in the per-link information 513 to be described below. The per-link information 513 includes a set of per-link information for each link supported in multi-link communication by the communication device 102 or 103 that transmits the multi-link capability element. In the case where the per-link information 513 to be described below is omitted, this field is also omitted.

[0102] The device type 529 is a field including capability information of the device type in multi-link communication indicating the communication device 102 or 103 that sends the element. Specifically, the device type 529 includes information indicating the device type to which the sending device of the element is classified among the following four types. The first type of device is a device that can simultaneously perform data transmission via a certain link and data reception via different links in multi-link communication. The second type of device is a device that can only simultaneously perform data transmission via different links when performing data transmission via a certain link. The third type of device is a device that can only simultaneously perform data reception via different links when performing data reception via a certain link. The fourth type of device is a device that can simultaneously maintain multiple links but cannot simultaneously perform data communication via different links when performing data communication via a certain link.

[0103] In the case where the multi-link capability element indicates the operation information, the device type 529 may indicate the device type of the two devices operating in the multi-link communication. For example, in the case where the communication device 102 sends an association response including this element, this field indicates the device type of the communication device operating in the communication via the link to be established through the exchange of this association. For example, in the case where information indicating the second type is sent as the operation information, even if the communication device 102 is a device that can operate as the first type, the communication device 102 operates as a device of the second type in the communication via the link to be established through the exchange of this association.

[0104] Alternatively, in the case where the multi-link capability element indicates request information, the device type 529 may indicate the device type that the communication device requests the communication device to operate in the multi-link communication. For example, in the case where the communication device 103 serving as an STA sends an association request including this element, this field indicates the device type that the communication device 103 is expected to operate in the multi-link communication. For example, in the case where this field includes information indicating the second type, it indicates that the communication device 103 requests the communication device 103 to operate as a second type of device in the multi-link communication with the communication device 102.

[0105] The per-band information 512 is a field including a band ID 531, supported bandwidth 532, supported CH 533, and asynchronous mode CH distance 534. In addition to these fields, the per-band information 512 also includes a maximum number of links 535 and the number of supported special streams (Nss) 536. For each frequency indicated by a band ID 531 to be described below, a set of per-band information 512 is included in the multi-link capability element.

[0106] The band ID 531 is a field including information for identifying a frequency band. Table 2 shows an example of the correspondence between the value included in the band ID 531 and the frequency band indicated by the value. For example, in the case where the band ID 531 includes 0 as a value, the per-band information 512 including this band ID 531 is information indicating information shared by links of multi-link communication in the 2.4 GHz band. The correspondence between the value included in the band ID 531 and the frequency band indicated by the value is not limited thereto. By increasing the number of bits of the band ID 531, the band ID 531 can be made to indicate a larger number of frequency bands.

[0107] [Table 2]

[0108] value Frequency band 0 2.4GHz frequency band 1 5GHz frequency band 2 6GHz band

[0109] The supported bandwidth 532 is a field including capability information indicating the bandwidth supported by the communication device 102 or 103 that has transmitted the element in the frequency band indicated by the band ID 531. The bandwidth indicated here is information indicating the bandwidth supported by the transmitting device of the element for one link when performing multi-link communication in the frequency band indicated by the band ID 531. Table 3 shows an example of the correspondence between the value included in the supported bandwidth 532 and the bandwidth indicated by the value. For example, in the case where the supported bandwidth 532 includes 0 as a value, it indicates that the bandwidth supported by the transmitting device of the element in the frequency band indicated by the band ID 531 is a 20MHz bandwidth. In the case where the value of the supported bandwidth 532 is greater than or equal to 1, when establishing a link of multi-link communication, the transmitting device of the element can support all bandwidths corresponding to values ​​less than or equal to the value. For example, in the case where the value of the supported bandwidth 532 is 2, the transmitting device supports all bandwidths of 20MHz, 40MHz, and 80MHz as the bandwidth of the link. The bandwidth supported by the communication devices 102 and 103 in the communication via only one link may be different from the bandwidth supported by the communication devices 102 and 103 in the multi-link communication. For example, the communication devices 102 and 103 may support 80 MHz as the bandwidth in the 5 GHz band in the communication via only one link, and may support 20 MHz as the bandwidth in the multi-link communication. The correspondence between the value included in the supported bandwidth 532 and the bandwidth indicated by the value is not limited thereto. By increasing the number of bits of the supported bandwidth 532, the supported bandwidth 532 may be enabled to indicate a larger number of frequency bands.

[0110] [Table 3]

[0111]

[0112]

[0113] In the case where the multi-link capability element indicates operation information, this field may indicate a bandwidth to be actually used in multi-link communication. For example, in the case where the communication device 102 serving as an AP sends an association response including this element, this field includes information indicating the bandwidth of a link to be established through the exchange of this association. For example, in the case where the communication devices 102 and 103 establish a link with a bandwidth of 40 MHz in the 2.4 GHz band, the value of the supported bandwidth 532 becomes 1.

[0114] Alternatively, in the case where the multilink capability element indicates request information, this field may indicate a bandwidth requested to be used in multilink communication. In the case where the communication device 103 serving as an STA transmits an association request including this element, this field indicates that the communication device 103 requests a bandwidth to be used by the communication device 102. Even in the case where this element indicates operation information or request information, this field may include capability information indicating a bandwidth supported by the transmitting device of the element in multilink communication.

[0115] Supported CH 533 is a field including capability information indicating the channels supported by the communication device 102 or 103 that has transmitted the element in the frequency band indicated by the band ID 531. The channel to be indicated here is information indicating the channels supported by the transmitting device of the element in the frequency band indicated by the band ID 531 in multi-link communication. Table 4 shows an example of the correspondence between each bit of supported CH 533 and the channel indicated by the bit. For example, in the case where a certain bit includes 0 as a value, it indicates that the transmitting device of the element does not support the channel indicated by the bit, and in the case where a certain bit includes 1 as a value, it indicates that the transmitting device supports the channel indicated by the bit. For example, in the case where supported CH 533 includes 0000010010100 as a value, it indicates that the transmitting device of this field supports multi-link communication via 3ch, 5ch and 8ch. The channels supported by the communication devices 102 and 103 in communication via only one link may be different from the channels supported by the communication devices 102 and 103 in multi-link communication. For example, the communication devices 102 and 103 may support all channels from 1 to 13ch in communication via only one link, and may support only a portion of channels such as 1ch and 5ch in multi-link communication. The correspondence between each bit of the supported CH 533 and the channel indicated by the bit is not limited to the correspondence shown in Table 4. By increasing the number of bits of the supported CH 533, the supported CH 533 may be enabled to indicate a larger number of channels. For example, Table 4 shows only channels in the 2.4GHz band as an example, but by increasing the number of bits, the supported CH 533 may be enabled to use 13 or more bits to indicate channels in the 5GHz band and the 6GHz band. Alternatively, in the case where information indicating the 5GHz band is included in the band ID 531, channels in the 5GHz band may be indicated in ascending order from bit 0. Similarly, in the case where information indicating the 6GHz band is included in the band ID 531, channels in the 6GHz band may be indicated in ascending order from bit 0.

[0116] [Table 4]

[0117] Bit Channel 0 1CH 1 2CH 2 3CH … … 12 13CH

[0118] In the case where the multilink capability element indicates operation information, this field may indicate a channel to be actually used in multilink communication. For example, in the case where the communication device 102 serving as an AP sends an association response including this element, this field includes information indicating the channel of the link to be established through the exchange of this association. For example, in the case where the communication devices 102 and 103 establish a link via 1ch and 4ch in the 2.4 GHz band, the value of supported CH 533 becomes 0000000001001.

[0119] Alternatively, in the case where the multilink capability element indicates request information, this field may indicate a channel requested to be used in multilink communication. For example, in the case where the communication device 103 serving as an STA transmits an association request including this element, this field indicates a channel for which the communication device 103 requests the communication device 102 to establish a link. Even in the case where this element indicates operation information or request information, this field may include capability information indicating channels supported by the transmitting device of the element in multilink communication.

[0120] Asynchronous mode CH distance 534 is a field including capability information indicating the channel spacing required by the transmitting device of the element in the asynchronous mode in the frequency band indicated by the frequency band ID 531. In asynchronous mode, since the communication via the link is performed asynchronously, if the channels used by the various links are close, the communication may interfere with each other. Since the channel spacing between the links required to properly decode the signal of the link varies depending on the communication device, this field is used to notify the capability information. In the case where the asynchronous mode CH distance 534 includes 4 as a value, for example, it indicates that the transmitting device of the element requires at least 4ch or more channel spacing in asynchronous mode. In the case where the above-mentioned asynchronous mode support 523 includes information indicating that the asynchronous mode is not supported, this field may include 0 as a value, or this field may be omitted. In the present exemplary embodiment, the channel spacing required in the asynchronous mode is indicated for each frequency band indicated by the frequency band ID 531, but the configuration is not limited thereto. Information shared by the frequency band may be indicated. Specifically, this field may be included in the shared information 511.

[0121] In the case where the multi-link capability element indicates operation information, this field may include information indicating the interval of channels to be actually used in the asynchronous mode of multi-link communication. For example, in the case where the communication device 102 serving as an AP sends an association response including this element, this field includes information indicating the channel interval between multiple links to be established through the exchange of this association.

[0122] Alternatively, in the case where the multilink capability element indicates request information, this field may include information indicating the interval of the channel requested to be used in the asynchronous mode of the multilink communication. Information indicating the minimum channel interval supported in the asynchronous mode of the multilink communication with the other device may be included. In the case where the element indicates operation information, this field includes a value greater than or equal to the larger channel interval of the channel interval indicated by the communication device 102 as capability information and the channel interval indicated by the communication device 103 as capability information. In the case where the asynchronous mode support 523 includes information indicating that the asynchronous mode will not be executed, or in the case where the asynchronous mode support 523 is omitted, this field may include 0 as a value. Alternatively, this field may be omitted. Alternatively, in the case where the communication device 103 serving as an STA sends an association request including this element, this field indicates the channel interval requested by the communication device 103 in the asynchronous mode of the multilink communication with the communication device 102. In the case where the communication device 103 does not request the execution of the asynchronous mode, this field may include 0 as a value, or this field may be omitted. In the case where the multilink capability element indicates operation information or request information, this field may be omitted.

[0123] The maximum number of links 535 is a field including capability information indicating the maximum number of links supported by the transmitting device that has transmitted the element in the case of performing multi-link communication in the frequency band indicated by the frequency band ID 531. In the case where the above-mentioned frequency band combination information 525 does not include information indicating support for multi-link communication via links in the same frequency band, this field may include 0 as a value. Alternatively, this field may be omitted. In this exemplary embodiment, the maximum number of links may be indicated for each frequency band, but the configuration is not limited thereto. The maximum number of links may be indicated as information common to all frequency bands. Specifically, this field may be included in the common information 511.

[0124] In the case where the multi-link capability element indicates operation information, this field may indicate the total number of links to be actually used in the multi-link communication in the frequency band indicated by the band ID 531. For example, in the case where the communication device 102 serving as an AP transmits an association response including this element, this field includes information indicating the number of one or more links to be established through the exchange of this association. For example, in the case where the communication devices 102 and 103 establish two links in the 2.4 GHz band, this field includes 2 as a value.

[0125] Alternatively, in the case where the multilink capability element indicates request information, this field may indicate the total number of links requested to be used in the frequency band indicated by the band ID 531 in the multilink communication. For example, in the case where the communication device 103 serving as an STA transmits an association request including this element, this field indicates the number of links that the communication device 103 requests to be established by the communication device 102. Even in the case where this element indicates operation information or request information, this field may include capability information indicating the maximum number of links that the transmitting device of the element can establish in the multilink communication.

[0126] Supported Nss 536 is a field including capability information indicating the maximum number of (spatial) streams supported by the transmitting device that has transmitted the element when performing multi-link communication in the frequency band indicated by the band ID 531. Nss represents the number of special streams. The number of streams indicated by this field is the number of streams in MIMO communication. In the case where MIMO communication is not supported in the multi-link communication in the frequency band indicated by the band ID 531, this field includes 0 or 1 as a value, or this field is omitted. In this exemplary embodiment, the maximum number of streams can be indicated for each frequency band, but the configuration is not limited thereto. The maximum number of streams can be indicated as information common to all frequency bands. Specifically, this field can be included in the common information 511.

[0127] In the case where the multilink capability element indicates operation information, this field may indicate the number of streams to be actually used in the frequency band indicated by the band ID 531 in the multilink communication. For example, in the case where the communication device 102 serving as an AP transmits an association response including this element, this field includes information indicating the number of streams of MIMO communication to be actually performed through the exchange of this association. For example, in the case where the communication devices 102 and 103 perform MIMO communication in which the number of streams is 3 via a link for performing multilink communication in the 2.4 GHz band, this field includes 3 as a value. In the case where MIMO communication is not to be performed, this field may include 0 or 1 as a value, or this field may be omitted.

[0128] Alternatively, in the case where the multilink capability element indicates request information, this field may indicate the number of streams requested to be used in the frequency band indicated by the band ID 531 in the multilink communication. In the case where the communication device 103 serving as an STA transmits an association request including this element, this field indicates the number of streams requested by the communication device 103 in MIMO communication in the multilink communication. In the case where the communication device 103 does not request MIMO communication, this field may include 0 or 1 as a value, or this field may be omitted. Even in the case where this element indicates operation information or request information, this field may include capability information indicating the maximum number of streams supported by the transmitting device of the element in MIMO communication in the multilink communication.

[0129] The per-link information 513 is a field including fields of a link ID 541, a band ID 542, a bandwidth 543, a CH 544, and an Nss 545. In the case where the multi-link capability element indicates capability information, the per-link information 513 indicates information about a channel via which the transmitting device of the element supports multi-link communication. In this case, several channels (links) supported by the transmitting device of the element in multi-link communication include a set of per-link information 513. Alternatively, in the case where the element indicates capability information, and in the case where a link of multi-link communication has been established, the per-link information 513 indicates information about the established link. In this case, several established links may include a set of per-link information 513. In this case, the communication device 102 indicates that the link of its information is a link established with at least one of the communication device 103 and a different communication device using the per-link information 513. In this case, the communication device 103 indicates that the link of its information is a link established with at least one of the communication device 103 and a different communication device using the per-link information 513. Alternatively, in the case where the element indicates capability information, it is not necessary to include the per-link information 513. The case where the multi-link capability element indicates operation information and the communication device 102 serving as an AP sends an association response including the element is not limited thereto. In this case, the per-link information 513 indicates information about the link to be established through the exchange of this association. In this case, the several links to be established through the exchange of this association include the per-link information 513. In addition, in the case where the request information is indicated by the communication device 103 sending an association request including the element, the per-link information 513 indicates information about the link that the communication device 103 requests to establish. In this case, the several links that the communication device 103 requests to establish include the per-link information 513.

[0130] The link ID 541 is a field including an identifier for identifying a link.

[0131] The band ID 542 is a field including information indicating the frequency band to which the link indicated by the link ID 541 belongs. This field is indicated similarly to the band ID 531.

[0132] The bandwidth 543 is a field including information indicating a bandwidth in the link indicated by the link ID 541. This field is indicated similarly to the supported bandwidth 532. In the case where the multi-link capability element indicates capability information, this field indicates a bandwidth supported in the link indicated by the link ID 541. In the case where the operation information is indicated by the communication device 102 serving as an AP transmitting an association response including this element, this field indicates a bandwidth to be used in the link indicated by the link ID 541. In the case where the request information is indicated by the communication device 103 serving as an STA transmitting an association request including this element, this field indicates a bandwidth requested by the communication device 103 in the link indicated by the link ID 541.

[0133] CH 544 is a field including information indicating a frequency channel of the link indicated by link ID 541. This field may include only a number indicating a channel. Alternatively, the channel may be indicated as shown in Table 4. In the case where the multi-link capability element indicates capability information, this field indicates a channel supported in the link indicated by link ID 541. In the case where the operation information is indicated by the communication device 102 serving as an AP sending an association response including this element, this field indicates a channel to be used in the link indicated by link ID 541. In the case where the request information is indicated by the communication device 103 serving as an STA sending an association request including this element, this field indicates a channel requested by the communication device 103 in the link indicated by link ID 541.

[0134] Nss 545 is a field including information indicating the number of streams of MIMO communication in the link indicated by link ID 541. In the case where MIMO communication will not be performed, this field may include 0 or 1 as a value, or this field may be omitted. In the case where the multilink capability element indicates capability information, this field indicates the maximum number of streams supported in the link indicated by link ID 541. In the case where the operation information is indicated by the communication device 102 serving as an AP sending an association response including this element, this field indicates the number of streams to be used in the link indicated by link ID 541. In the case where the request information is indicated by the communication device 103 sending an association request including this element, this field indicates the number of streams requested by the communication device 103 in the link indicated by link ID 541.

[0135] By sending and receiving MAC frames including the above-mentioned multi-link capability elements, the communication devices 102 and 103 exchange capability information, operation information and request information of multi-link communication. In this exemplary embodiment, the capability information, operation information and request information of multi-link communication are indicated by the same multi-link capability element, but the configuration is not limited to this. Capability information and operation information or capability information and request information can be indicated by different information elements. In this case, for example, capability information can be indicated by an element including common information 511 and per-band information 512. In addition, operation information and request information can be indicated by an element including common information 511 and per-link information 513. In the case where the multi-link capability element indicates capability information, a part of the field can indicate operation information or request information. Alternatively, in the case where the multi-link capability element indicates operation information or request information, a part of the field can indicate capability information.

[0136] Figure 5 The multi-link capability element shown in includes fields of the primary CH 521, the supported CH 533, and the CH 544 as information indicating the frequency channel. However, the configuration is not limited thereto. It is only required that the multi-link capability element includes at least any one of the primary CH 521, the supported CH 533, and the CH 544 as information indicating the frequency channel.

[0137] The names of the fields, the number of fields, and the order of the fields are not limited to Figure 5 Any fields can be included in Figure 5 In addition, the fields included in the common information 511 may be included in the per-band information 512 or the per-link information 513. The fields included in the per-band information 512 and the per-link information 513 may also be included in other fields, or may be included in the common information 511. In addition, the fields included in the common information 511 may be omitted. Figure 5 Any of the fields shown in .

[0138] Figure 8 and 9 The diagram illustrates information included in the body part of a MAC frame of a beacon and a probe response to be transmitted by the communication device 102. The frame format of the MAC frame can be divided into a header part and a body part to be transmitted and received in the following order. More specifically, the header part is transmitted and received first, and the body part is transmitted and received next. The header part includes information indicating the type of the MAC frame. Specifically, in the case of a beacon, for example, the header part includes information indicating that the type of the MAC frame is a management frame and that the subtype is a beacon. Similarly, in the case of a probe response, the header part includes information indicating that the type of the MAC frame is a management frame and that the subtype is a probe response.

[0139] Figure 8The figure shows information included in the body part of the MAC frame of the beacon to be transmitted by the communication device 102. The beacon includes various types of information indicated on the column of information as elements. These multiple pieces of information are transmitted and received in the order indicated by the sequence. The beacon does not need to include Figure 8 All of the multiple pieces of information shown in , and only at least a portion of the information is required to be included.

[0140] Among these multiple pieces of information, the timestamp of order = 1, the beacon interval of order = 2, and the capability information of order = 3 correspond to the information necessarily included in the beacon. In addition, the SSID of order = 4 and the supported rate and BSS membership selector of order = 5 also correspond to the information necessarily included in the beacon.

[0141] The timestamp includes information indicating a value of a timing synchronization function (TSF) timer of a transmitting device of the MAC frame.

[0142] The beacon interval includes information indicating a transmission interval of a beacon to be transmitted by the transmission means of the MAC frame.

[0143] The capability information includes information indicating whether the transmission device of the MAC frame can perform a point coordination function (PCF). The capability information also includes information indicating whether the transmission device of the MAC frame requires encryption in data communication.

[0144] SSID includes information indicating an identifier of an extended service set (ESS) or an independent basic service set (IBSS) of a transmission device of a MAC frame. As an identifier of an ESS, ESSID which is an identification name of an AP is included. Generally, SSID is included as ESSID.

[0145] The supported rate and BSS membership selector includes information indicating wireless transmission rates supported by the transmitting device of the beacon.

[0146] Each piece of information to be transmitted later than the supported rates and BSS membership selectors may be included in the MAC frame, but need not be included.

[0147] In this exemplary embodiment, the following description will be made Fig.10 The switching destination information shown in is arranged as an element of order=Z, which is transmitted later than the EHT capability element and the EHT operation element, such as Figure 8 As shown in . In this example, the name of the element indicating the switching destination information of the multi-link communication is the switching destination link information, but the name is not limited to this. For example, a name such as a multi-link report element may be used. The switching destination information is arranged in a manner that is transmitted earlier than the vendor-specific element to be transmitted last in the MAC frame.

[0148] The EHT capability element includes information indicating the capabilities of the transmitting device of the MAC frame related to the communication conforming to the IEEE 802.11be standard. Specifically, for example, information indicating the capabilities of the physical layer (PHY) of the transmitting device of the MAC frame in the communication conforming to the IEEE 802.11be standard (EHT PHY capability information) is included. In addition to this or in lieu of this, information indicating the capabilities of the MAC of the transmitting device of the MAC frame in the communication conforming to the IEEE 802.11be standard (EHT MAC capability information) may be included. By transmitting the EHT capability element, the transmitting device of the MAC frame can indicate that the transmitting device is a device that can perform communication conforming to the IEEE802.11be standard. The EHT capability element can be transmitted in the beacon following the element of order = 87.

[0149] The EHT Operation element includes information for controlling a communication device in communications conforming to the IEEE 802.11be standard. The operation of a communication device that supports communications conforming to the IEEE 802.11be standard and participates in a BSS conforming to the IEEE 802.11be standard is controlled by the EHT Operation element. The EHT Operation element may be transmitted in a beacon following the EHT Capability element.

[0150] In the case where the beacon transmitting device transmits a beacon including switching destination information of multi-link communication, the beacon includes at least one of an EHT capability element and an EHT operation element. Compatibility can be ensured by transmitting the switching destination information of the multi-link communication later than at least one of the EHT capability element and the EHT operation element. Because only a communication device that complies with a standard established earlier than the IEEE802.11ax standard cannot interpret the content of the switching destination information of the multi-link communication (even if the communication device receives the switching destination information), the communication device discards the switching destination information and subsequent information. For example, if the switching destination information is transmitted earlier than the information about the communication that complies with the IEEE 802.11ax standard, the receiving device may become unable to obtain information about the communication that complies with the IEEE 802.11ax standard from the transmitting device. By arranging the switching destination information of the multi-link communication in a manner that is transmitted later than the EHT capability and the EHT operation, the receiving device of the beacon can obtain information about the communication that complies with the standard established earlier than the IEEE 802.11be standard.

[0151] The arrangement position is not limited to this. It is only required that the switching destination information of the multi-link communication is arranged in a manner that is transmitted later than at least the SSID and the supported rate and BSS membership selector in the beacon. By arranging the switching destination information of the multi-link communication in a manner that is transmitted later than the information necessarily included in the beacon, only a receiving device that complies with the standards established earlier than the IEEE 802.11ax standard can also obtain the information necessarily included in the beacon. With this configuration, compatibility with legacy terminals (which only comply with the standards established earlier than the IEEE 802.11ax standard) can be ensured.

[0152] Similarly, Figure 5 The multi-link capability element shown in is also arranged in a manner that is transmitted later than at least one of the EHT capability element and the EHT operation element. With this configuration, compatibility with legacy terminals can be ensured. The arrangement position is not limited to this, and the multi-link capability element can be arranged in a manner that is transmitted later than the SSID or supported rate and BSS membership selector. With this configuration, compatibility with legacy terminals can be ensured.

[0153] Fig. 9 The diagram illustrates information included in the body portion of a MAC frame of a probe response to be sent by the communication device 103. The probe response includes various types of information indicated on the columns of information as elements. These multiple pieces of information are sent and received in the order indicated by the sequence. The probe response does not need to include Fig. 9 All of the multiple pieces of information shown in , and only at least a portion of the information is required to be included.

[0154] Similar to the beacon, the probe response also necessarily includes the timestamp of order = 1, the beacon interval of order = 2, and the capability information of order = 3. In addition to these, the SSID of order = 4 is necessarily included. Unlike the beacon, the supported rates and BSS membership selector of order = 5 may be included, but need not be included.

[0155] In this exemplary embodiment, the following description will be made Fig.10 The switching destination information shown in is arranged as an element of order=Z, which is transmitted later than the EHT capability element and the EHT operation element, such as Fig. 9 As shown in . In this example, the name of the element indicating the switching destination information of the multi-link communication is the switching destination link information, but the name is not limited to this. For example, a name such as a multi-link report element may be used. The switching destination information is arranged in a manner that is transmitted earlier than the vendor-specific element to be transmitted second to last in the MAC frame. By arranging the switching destination information in a manner that is transmitted later than at least one of the EHT capability element and the EHT operation element, compatibility with legacy terminals can be ensured.

[0156] The arrangement position is not limited to this, and it is only required that the switching destination information of the multilink communication is arranged in such a manner as to be transmitted later than the SSID in the probe response. With this configuration, compatibility with legacy terminals can be ensured.

[0157] In the case where the probe request includes information indicating the switching destination information requesting multi-link communication, the sending device of the probe response can transmit the switching destination information after the SSID without transmitting other elements. By avoiding sending unnecessary elements, the sending device of the probe response can reduce the number of elements to be transmitted and reduce overhead.

[0158] Figure 5 The multi-link capability element shown in is also arranged in a manner that is transmitted later than at least one of the EHT capability element and the EHT operation element. With this configuration, compatibility with legacy terminals can be ensured. The arrangement position is not limited to this, and the multi-link capability element can be arranged in a manner that is transmitted later than the SSID. With this configuration, compatibility with legacy terminals can be ensured.

[0159] Fig.10 An example of the frame format of the switching destination link information element (information element) is illustrated. Figure 8 The switching destination link information of the order = Z shown in or 9 includes the following: Fig.10 The information shown in .

[0160] The switching destination link information element includes fields of element ID 1101, length 1102, element ID extension 1103, and number of links 1104. In addition to this, the switching destination link information element also includes a field of optional sub-element 1105. The communication device 102 generates the following sub-element 1105 in sequence from the element ID 1101: Fig.10 , and sends the switching destination link information element to different communication devices. In this case, the communication device 102 sends the switching destination link information element to different communication devices after generating all the fields in the frame. Alternatively, the communication device 102 may perform the transmission concurrently with the generation of the field. Specifically, for example, the communication device 102 may perform the generation of the length 1102 concurrently with the transmission of the generated element ID 1101.

[0161] The element ID 1101 includes a value indicating that this element is a switching destination link information element.

[0162] The length 1102 includes information specifying the number of octets of the handover destination link information element following the length 1102 (excluding the length 1102).

[0163] The element ID extension 1103 includes a value for identifying different elements to which the same element ID is assigned. In the case where the element ID extension is not assigned to the handover destination link information element in the IEEE802.11be standard, this field is omitted.

[0164] The number of links 1104 includes information indicating the number of links whose information is indicated by the switching destination link information element. This field is a field in an unsigned integer format. The length of this field is 9 bits in a manner that can identify 0 to 511, but the length can be greater than or equal to, or less than or equal to this length. By including this field in the switching destination link information, a receiving device of the switching destination link information can identify the number of links whose information is indicated by the switching destination link information element without analyzing the following optional sub-element 1105. Since the number of links indicating its information can be obtained by analyzing the optional sub-element 1105, this field can be omitted.

[0165] The optional sub-element 1105 indicates information about each link. The optional sub-element 1105 includes link reports 1111 to 111m as sub-elements (or sub-fields) in a number corresponding to the number of links whose information is indicated by the handover destination link information element.

[0166] The communication device 102 that transmits the switching destination link information transmits, as the switching destination link information, information about at least one of the links excluding the link to be used for the transmission of the switching destination link information among the links already established with the communication device 103. In addition to this or in lieu thereof, the communication device 102 may transmit information about the links that can be established from now on with the communication device 103. Specifically, the communication device 102 transmits information about the wireless network that has been constructed by the communication device 102 in which the link with the communication device 103 has not been established. In addition to these multiple pieces of link information, the communication device 102 may also transmit information including information about the link to be used for the transmission of the switching destination link information.

[0167] Link reports 1111 to 111m each include fields for sub-element ID 1121, length 1122, BSSID 1123, BSSID information 1124, and operation level 1125. In addition to these fields, link reports 1111 to 111m each include fields for channel number 1126, PHY type 1127, and optional sub-element 1128.

[0168] In the present exemplary embodiment, as the frame format of the link report, the frame format of the neighbor report element defined in the IEEE 802.11 series of standards is used.The frame format of the link report is not limited to the frame format of the neighbor report.

[0169] The sub-element ID 1121 includes information indicating that this sub-element is a link report. In the case where the neighbor report is appropriated as a link report, 52 is included as an ID indicating the neighbor report. This field can be omitted.

[0170] The length 1122 includes information specifying the number of octets of the link report following the length 1122 (excluding the length 1122).

[0171] The BSSID 1123 includes information indicating a BSSID as identification information of a wireless network in which a link whose information is indicated by the link report is constructed. Alternatively, a field of a link ID may be included as identification information of the link instead of or in addition to the BSSID 1123. In the case of indicating information about a link that has not yet been constructed, the link ID field does not need to be included. Alternatively, the link ID field may include a value indicating that the link has not yet been established.

[0172] BSSID information 1124 includes information indicating whether the wireless network indicated by BSSID 1123 enables communication compliant with the IEEE 802.11be standard. In addition to this, information indicating whether the wireless network indicated by BSSID 1123 enables communication compliant with the IEEE 802.11ax standard or the IEEE 802.11n standard may also be included. This field may be omitted.

[0173] The operation level 1125 includes information indicating a set of frequency channels via which the communication device 102 can perform communication. This field may be omitted.

[0174] The channel number 1126 includes information indicating a frequency channel to be used in the wireless network indicated by the BSSID 1123. In the case where information on an already established link is indicated in the link report, the channel number 1126 may include information indicating a frequency channel used in the link.

[0175] The PHY type 1127 includes information indicating a physical media type of a MAC frame including a handover destination link information element.

[0176] Optional sub-element 1128 includes information about the link. Optional sub-element 1128 includes one or more measurement report fields. Measurement reports 1131 to 113n are included in the optional sub-element 1128 by the number of types of information about the corresponding link. As information about the link, information indicating the possibility of obtaining a transmission opportunity of the communication device 102 or 103 is included as information for determining the switching or selection of the link to be used in the multi-link communication. For example, information indicating the ratio of the period of time when the frequency channel used by the corresponding link is busy or the ratio of the period of time when the frequency channel is not busy relative to a predetermined period is included as information about the link. Alternatively, information indicating whether a signal or radar sent from a different communication device has been detected in the frequency channel used by the corresponding link is included. Alternatively, information indicating the power of the signal received by the communication device 102 in the frequency channel used by the corresponding link is included. The power of the signal received by the communication device 102 refers to the power of the signal sent from the communication device 103 and received by the communication device 102. Alternatively, information indicating the signal-to-noise ratio in the frequency channel used by the corresponding link and information about the total power of noise and interference waves are included. Alternatively, information about the number of management frames and data frames received via the corresponding link or the wireless network in which the corresponding link is established is included. The communication device 102 is only required to include at least one of the above information into the optional sub-element 1128 as a measurement report for one link.

[0177] The measurement reports 1131 to 113n each include fields of sub-element ID 1141, length 1142, and measurement token 1143. In addition to these fields, the measurement reports 1131 to 113n each include fields of measurement report mode 1144, measurement type 1145, and measurement report 1146.

[0178] The sub-element ID 1141 includes information indicating that this sub-element is a measurement report. This field may be omitted.

[0179] The length 1142 includes information specifying the number of octets of the measurement report following the length 1142 (excluding the length 1142).

[0180] The measurement token 1143 includes the same value as the measurement token of the measurement request element received from the communication device 103. By sending a probe request including a measurement request element to the communication device 102, the communication device 103 can request the communication device 102 to send the switching destination link information. The communication device 102 can send a measurement request frame including a measurement request element instead of the probe request. The measurement request frame can be sent at any timing. In the case where the communication device 102 does not send the measurement reports 1131 to 113n based on the reception of the measurement request element, 0 is set in the measurement token 1143. This field can be omitted.

[0181] The measurement type 1145 includes information indicating the type of information included in a measurement report 1146 to be described below. The information included in the measurement report 1146 is the above-mentioned information on the link.

[0182] In this exemplary embodiment, a type indicating information about a type that is not applied to a neighbor report element in a standard established earlier than the IEEE 802.11ax standard but is applied to a different element may be specified as a measurement type. For example, basic, clear channel assessment (CCA), or received power indicator (RPI) histogram may be specified as a type. Alternatively, channel load, noise histogram, beacon, or frame may be specified as a type.

[0183] The measurement report field 1146 includes information indicating information about the frequency channel, the measurement start time, and the length of the measurement period, regardless of the measurement type. Then, information about the type indicated by the measurement type under these conditions is included. Based on the type specified as the measurement type, the measurement report field is sometimes referred to as a [measurement type name] report. For example, in the case where the measurement type is basic, the measurement report field is referred to as a basic report.

[0184] In the case where the measurement type 1145 indicates basic, the measurement report 1146 (basic report) includes information indicating whether a valid MAC protocol data unit (MPDU) has been received from a different BSS. In addition to or instead of this information, information indicating whether a short training symbol sequence without a valid signal field connected has been received is also included. In addition to or instead of these multiple pieces of information, information indicating whether a high power that cannot be identified as one of a radar wave, an OFDM preamble, or a valid MPDU has been received or whether a radar wave has been received is included.

[0185] In the case where the measurement type 1145 indicates CCA, the measurement report 1146 (CCA report) includes information indicating the ratio of time that the frequency channel is busy.

[0186] In the case where the measurement type 1145 indicates an RPI histogram, the measurement report 1146 includes information indicating a frequency distribution in which the power observed by the antenna is used as a level. In this case, the measurement report 1146 may be referred to as an RPI histogram report.

[0187] In case the measurement type 1145 indicates channel load, the measurement report 1146 (Channel Load Report) includes information indicating the ratio of time that the frequency channel is busy. In addition or instead of this, information about switching to a new bandwidth is included.

[0188] In the case where the measurement type 1145 indicates a noise histogram, the measurement report 1146 (noise histogram report) includes information indicating the total average power of noise and interference waves. In addition to this or in lieu of this, information indicating the frequency distribution in which the total power of noise and interference waves is used as a level is included.

[0189] In the case where the measurement type 1145 indicates a beacon, the measurement report 1146 (beacon report) includes information indicating the received power and signal to noise ratio of the beacon. Alternatively, in addition to or in lieu of this, information indicating the received power and signal to noise ratio of the measurement pilot or probe response frame is included.

[0190] In case the measurement type 1145 indicates a frame, the measurement report 1146 (frame report) includes information indicating the average power of the received frames. Alternatively, in addition to or in lieu of this, information indicating the number and signal-to-noise ratio of received data frames and management frames is included.

[0191] In this exemplary embodiment, Fig.10 As shown in , all multiple pieces of switching destination information are included in a single element (switching destination link information element). However, the frame format is not limited to this, and the communication device 102 may independently include multiple elements as switching destination information. Specifically, instead of Fig.10 , the MAC frame may include link reports 1111 to 111m, not as sub-elements, but as elements. In this case, the sub-element ID field 1121 is replaced by the element ID field or the element ID field and the element ID extension field. The identifier corresponding to the element is stored in these fields. In the case where the neighbor report is appropriated as a link report, 52 is included as an ID indicating the neighbor report.

[0192] In the present exemplary embodiment, the link report includes sub-elements of measurement reports 1131 to 113n as information about the link, but the frame format is not limited thereto. Instead of the measurement report, other elements defined in the IEEE 802.11 series of standards and including information useful for STA to determine the possibility of acquiring a transmission opportunity may be included as sub-elements.

[0193] For example, elements such as BSS load, BSS average access delay, or BSS AC access delay defined in a standard established earlier than the IEEE 802.11ax standard may be included as sub-elements. Alternatively, instead of or in addition to this, elements such as extended BSS load or HE BSS load may be included as sub-elements. It is sufficient for one or more of these elements to be included as sub-elements in a link report. Alternatively, at least one of the above elements may be included as a sub-element in the measurement report sub-element.

[0194] In the case of including the above elements as sub-elements, the element ID fields of these elements are replaced by the sub-element ID field. Then, the identifier for identifying the sub-element in the measurement report or link report is stored in the sub-element ID field. In the case of the element ID extension field, the element ID extension field is deleted. However, the identifier corresponding to the combination of the value of the element ID field and the value of the element ID extension field is stored in the sub-element ID field.

[0195] The BSS load includes information indicating the number of STAs included in the targeted BSS, information indicating the ratio of time when the medium is busy, and information indicating the total remaining time in time when the medium can be used by admission control.

[0196] The BSS average access delay includes information indicating an average medium access delay time of the AP.

[0197] The BSS AC access delay includes information indicating an average medium access delay time for each access category (ie, AC_BE, AC_BK, AC_VI, and AV_VO).

[0198] The extended BSS load includes information indicating the number of very high throughput (VHT) STAs that have multi-user (MU) beamforming capabilities and are associated with the targeted BSS. In addition to or instead of this, information indicating the unoccupancy rate in the spatial flow domain during the time when the medium is busy, and information indicating the time occupancy rate of the secondary 20 MHz band, 40 MHz band, or 80 MHz band is included.

[0199] The HE BSS load includes information indicating the number of high efficiency (HE) STAs associated with the target BSS, and information indicating the ratio of the time when the medium is busy for communication between the AP and the HE STA. The HE STA refers to a STA that supports wireless communication compliant with the IEEE 802.11ax standard. In addition to or instead of this, information indicating the unoccupied rate in the frequency domain during the time when the medium is busy, and information indicating the unoccupied rate in the space flow domain during the time when the medium is busy are included.

[0200] In addition to or in lieu of these elements, the link report or measurement report may include, as a sub-element, an element that is not defined in a standard that was formulated earlier than the IEEE 802.11ax standard. In this exemplary embodiment, one of such elements will be referred to as the EHT BSS load. The EHT BSS load includes information indicating the number of EHT STAs associated with the BSS as the target. The EHT BSS refers to a STA that supports wireless communications that comply with the IEEE 802.11be standard. The number of EHT STAs is calculated by counting STAs that include at least one of the EHT capability and the EHT operation in the management frame. In addition to or in lieu of this, information indicating the ratio of the time when the medium is busy with communication between the AP and the EHT STA, and information indicating the unoccupied rate in the frequency domain during the time when the medium is busy are included. In addition to or in lieu of these multiple pieces of information, information indicating the unoccupied rate in the spatial domain during the time when the medium is busy may be included.

[0201] Figure 6 1 is a flowchart illustrating processing to be performed by the control unit 202 reading out and executing a computer program stored in the storage unit 201 in a case where the communication device 103 performs multi-link communication.

[0202] The processing in this flowchart starts in accordance with the power of the communication device 103 being turned on. Alternatively, the communication device 103 may start the processing in this flowchart in accordance with a start instruction of multi-link communication being issued from a user or an application. Alternatively, the communication device 103 may start the processing in this flowchart in accordance with the data amount of data to be transmitted to the communication device 102 becoming greater than or equal to a predetermined threshold value.

[0203] In step S601, first, the communication device 103 obtains the capability information of the other party's device in multi-link communication. Specifically, the communication device 103 obtains the capability information of the communication device 102 by receiving a beacon including a multi-link capability element that has been sent by the communication device 102. Alternatively, the communication device 103 may perform the processing in this step by receiving a probe response including a multi-link capability element that has been sent by the communication device 102. In this case, the processing in this step is exchanged with the processing order in step S602 to be described below.

[0204] Next, in step S602, the communication device 103 notifies its own capability information in multi-link communication. Specifically, the communication device 103 notifies its own capability information in multi-link communication by sending a probe request including a multi-link capability element. In the case where the capability information of the other device has been acquired before this step, the capability information to be notified by itself can be determined based on the capability information of the other device. Specifically, the communication device 103 can determine the capability information to be notified in this step in a manner that does not exceed the capability of the communication device 102. For example, the case where the communication device 103 supports multi-link communication in 2.4 GHz band, 5 GHz band and 6 GHz band and the communication device 102 only supports multi-link communication in 2.4 GHz band and 5 GHz band will be considered. In this case, in this step, the communication device 103 notifies support for multi-link communication in 2.4 GHz band and 5 GHz band as capability information. In the case where the communication device 103 sends an association request including request information indicating a request for multi-link communication to the communication device 102 in step S603 to be described below, the processing in this step can be omitted.

[0205] Next, in step S603, the communication device 103 sends an association request including request information about multilink communication. The request information to be sent in this step indicates information about multilink communication requested to be performed by the communication device 103. In this step, the communication device 103 may send an association request that does not include request information.

[0206] In step S604, the communication device 103 determines whether an association response has been received from the communication device 102 serving as the AP. In the case where the communication device 103 has not received an association response ("No" in step S604), the communication device 103 makes a "No" determination in this step and performs the processing in this step again. In the case where a "Yes" determination is not made in this step even if a predetermined time has passed since the association request was sent in step S603, the communication device 103 notifies the user of an error and ends the processing of this flow. On the other hand, in the case where the communication device 103 has received an association response ("Yes" in step S604), the communication device 103 makes a "Yes" determination in this step and performs the processing in step S605.

[0207] In step S605, the communication device 103 starts multilink communication with the communication device 102. In the case where the association response received in step S604 includes operation information about the multilink communication, the communication device 103 starts multilink communication based on the operation information. Alternatively, in the case where the request information has been sent in step S603 and the association response including only information indicating permission has been received in step S604, the communication device 103 starts multilink communication based on the request information sent in step S603. In the present exemplary embodiment, in step S605, the communication device 103 starts multilink communication via the multiple links established with the communication device 102.

[0208] If the communication device 103 starts the multi-link communication with the communication device 102, then in step S606, the communication device 103 obtains the switching destination information of the multi-link communication from the communication device 102. Specifically, the communication device 103 receives from the communication device 102 the information including Fig.10 The communication device 103 may receive a beacon including the switching destination link information element from the communication device 102 at each beacon interval of the communication device 102. In addition to the switching destination link information element, the beacon to be received in this step may also include a multi-link capability element indicating capability information of the communication device 102 in multi-link communication.

[0209] In this exemplary embodiment, the communication device 103 receives a beacon in step S606, but the management frame to be received is not limited thereto. The communication device 103 may receive a probe response including a switching destination link information element. In this case, the communication device 103 sends a probe request for requesting switching destination information to the communication device 102 at a timing between steps S605 and S606. The probe request to be sent by the communication device 103 may include information indicating the request for switching destination information. The probe response does not need to include a multilink capability element indicating capability information of the communication device 102 in multilink communication.

[0210] In step S607, the communication device 103 determines whether to change the link to be used for multi-link communication with the communication device 102. Specifically, the communication device 103 determines whether a link change instruction has been received from the user. In the case where a link change instruction has been received from the user ("yes" in step S607), the communication device 103 makes a "yes" determination in this step and performs the processing in step S608. On the other hand, in the case where a link change instruction has not been received from the user ("no" in step S607), the communication device 103 makes a "no" determination in this step and performs the processing in step S609. In this case, the communication device 103 can display the switching destination information indicated by the switching destination link information element acquired in step S606 on the display unit, and display a screen for asking the user whether to change the link. Alternatively, it is not necessary to make a determination based on a user instruction, and the communication device 103 can make a determination in this step based on the switching destination link information element acquired in step S606. For example, the communication device 103 makes the determination in this step by comparing the acquisition possibility of the transmission opportunity of the communication device 103 in the link used for data communication with the communication device 102 with the acquisition possibility of the transmission opportunity in the different link indicated by the switching destination link information element. In this case, in the case where the acquisition possibility of the transmission opportunity of the communication device 103 in the different link is higher than the acquisition possibility of the transmission opportunity in the currently used link, the communication device 103 makes a "yes" determination in this step. On the other hand, in the case where the acquisition possibility of the transmission opportunity of the communication device 103 in the different link is lower than the acquisition possibility of the transmission opportunity in the currently used link, the communication device 103 makes a "no" determination in this step. In this case, a link with a lower ratio of a period of time during which the frequency channel used by the link is busy relative to a predetermined period is considered to have a higher acquisition possibility of the transmission opportunity. In addition, a link with a higher signal-to-noise ratio is considered to have a higher acquisition possibility of the transmission opportunity. Alternatively, a link with a higher power of a signal received in a frequency channel used by the link is considered to have a higher acquisition possibility of the transmission opportunity. In addition, a link with a lower total power of noise and interference waves in a frequency channel used by the link is considered to have a higher acquisition possibility of the transmission opportunity. Furthermore, a link in which the number of management frames or data frames received via the wireless network in which the link is established is smaller is considered to have a higher possibility of acquiring a transmission opportunity. Alternatively, in the case where the communication device 103 has not yet obtained the expected throughput in the link for data communication with the communication device 102, the communication device 103 makes a determination of "yes" in this step. The threshold value of the throughput may be set by the user or may be preset in the communication device 103.

[0211] In the present exemplary embodiment, after acquiring the switching destination information in step S606, the communication device 103 determines in step S607 whether to change the link, but the processing flow is not limited thereto. The communication device 103 may first determine whether a link change instruction has been issued from the user, and then acquire the switching destination information. After the processing in step S605, the communication device 103 makes the determination in step S607 based on the user instruction, and in the case where the communication device 103 makes a determination of "yes", the communication device 103 sends a probe request for requesting the switching destination information to the communication device 102. Thereafter, in step S606, the communication device 103 acquires the switching destination information from the communication device 102, and performs the processing in step S608 to be described below based on the acquired switching destination information. In the case where the communication device 103 makes a determination of "no" in step S607 ("no" in step S607), the communication device 103 performs the processing in step S609 to be described below.

[0212] In the case where the communication device 103 makes a determination of "yes" in step S607 ("yes" in step S607), in step S608, the communication device 103 performs a link change process. The link change process specifically refers to switching the link used for data communication with the communication device 102 to a different link. Alternatively, the link change process is not limited to this, and another link may be added as a link to be used for data communication with the communication device 102. Alternatively, the communication device 103 may establish a new link with the communication device 102, and switch or add a link to be used for data communication with the communication device 102. In addition to or instead of the link to be used for data communication with the communication device 102, the communication device 103 may perform a change process of the link used to send the control frame.

[0213] In step S608, the communication device 103 sends a link change request to the communication device 102. The communication device 103 starts data communication via the new link based on the response to the sent link change request returned from the communication device 102. Alternatively, in the case of establishing a new link with the communication device 102, the communication device 103 may send an association request in step S608 similar to step S604. In this case, the communication device 103 starts data communication via the new link based on the association response received from the communication device 102.

[0214] In this case, the communication device 103 may transmit the link change request or the association request via a frequency channel used for communication of management frames with the communication device 102. Alternatively, the communication device 103 may transmit these signals via a frequency channel used for data communication.

[0215] In step S609, the communication device 103 determines whether to end the multilink communication. Specifically, the communication device 103 determines whether an end instruction of the multilink communication with the communication device 102 has been issued from the user. In the case where an end instruction of the multilink communication has been issued from the user ("Yes" in step S609), the communication device 103 makes a "Yes" determination in this step and performs the processing in step S610. On the other hand, in the case where an end instruction of the multilink communication has not been issued from the user ("No" in step S609), the communication device 103 performs the processing in step S606 again.

[0216] In step S610, the communication device 103 disconnects the link with the communication device 102. In this case, the communication device 103 disconnects multiple links established with the communication device 102, except for one link. Specifically, the communication device 103 sends a disassociation frame including information for making the link to be disconnected identifiable to the communication device 102. The communication device 103 may send the disassociation frame via the maintained link that is not disconnected, or may send the disassociation frame via any one of the links to be disconnected. In this exemplary embodiment, one link with the communication device 102 is maintained, but the disconnection process is not limited to this. In this step, all links may be disconnected. If the communication device 103 performs the process in step S610, the communication device 103 ends the process of this flow.

[0217] The communication device 103 may make the determination in step S609 not based on a user instruction but based on whether a link for multi-link communication with the communication device 102 has been maintained. In this case, the communication device 103 skips the processing in step S610. In the case where multiple links are maintained with the communication device 102, the communication device 103 makes a "no" determination in step S609. On the other hand, in the case where multiple links are not maintained with the communication device 102, the communication device 103 makes a "yes" determination in step S609. Alternatively, in the case where one or more links are maintained with the communication device 102, the communication device 103 may make a "yes" determination in step S609, and in the case where no link is maintained, the communication device 103 may make a "no" determination in step S609.

[0218] So far, if Figure 6 As shown in , the communication device 103 can change the link of the multilink communication with the communication device 102 by acquiring the switching destination information after starting the multilink communication with the communication device 102. The communication device 103 can thereby prevent the decrease in the throughput of the multilink communication with the communication device 102 and enhance the communication efficiency.

[0219] Figure 71 is a flowchart illustrating processing to be performed by the control unit 202 reading out and executing a computer program stored in the storage unit 201 in a case where the communication device 102 performs multi-link communication.

[0220] The processing in this flowchart starts in accordance with the power of the communication device 102 being turned on. Alternatively, the communication device 102 may start the processing in this flowchart in accordance with a start instruction of multi-link communication being issued from a user or an application. Alternatively, the communication device 102 may start the processing in this flowchart in accordance with the data amount of data to be transmitted to the communication device 103 becoming greater than or equal to a predetermined threshold value.

[0221] In step S701, first, the communication device 102 notifies its own capability information in multi-link communication. Specifically, the communication device 102 notifies its own capability information in multi-link communication by sending a beacon including a multi-link capability element. Alternatively, the communication device 102 may perform the processing in this step by sending a probe response including a multi-link capability element according to receiving a probe response from the communication device 103. In this case, the processing in this step is exchanged with the processing order in step S702 to be described below.

[0222] Next, in step S702, the communication device 102 obtains the capability information of the other device in multi-link communication. Specifically, the communication device 102 obtains the capability information of the other device in multi-link communication by receiving a detection request including a multi-link capability element. In the case where a detection request including a multi-link capability element has not been received from the other device, the processing in this step can be omitted.

[0223] If the communication device 102 receives the probe request from the communication device 103, the communication device 102 returns a probe response as a response. In this case, in the case of transmitting a beacon including a multi-link capability element, the probe response does not need to include the element.

[0224] In step S703, the communication device 102 determines whether an association request has been received from the communication device 103. In the case where an association request has not been received ("No" in step S703), the communication device 102 makes a "No" determination in this step and performs the processing in this step again. In the case where a "Yes" determination is not made in this step even if a predetermined time has passed since the probe response was sent in step S702, the communication device 102 notifies the user of an error and ends the processing of this flow. On the other hand, in the case where an association request has been received ("Yes" in step S703), the communication device 102 makes a "Yes" determination in this step and performs the processing in step S704.

[0225] Next, in step S704, the communication device 102 sends an association response as a response to the association request. In the case where the request information has not been received from the communication device 103 in step S703, the communication device 102 sends an association response including the operation information in the multi-link communication with the communication device 103. In this case, the communication device 102 determines the type of operation information to be included in the association response based on the capability information of the communication device 103 in the multi-link communication. The operation information to be included in the association response and sent by the communication device 102 indicates information about the multi-link communication to be actually performed between the communication devices 102 and 103. Even in the case where the association request received in step S703 includes the request information from the communication device 103, the communication device 102 may send an association response including the operation information. In this case, the communication device 102 determines the type of operation information to be included in the association response based on the request information included in the association request received from the communication device 103. Alternatively, in the case where the request information has been received from the communication device 103 in step S703, the communication device 102 may send an association response including only information indicating whether the multi-link communication is to be permitted.

[0226] In step S705, the communication device 102 starts multilink communication with the communication device 103. In the case where the operation information about the multilink communication is included in the association response sent in step S704, the communication device 102 starts the multilink communication based on the operation information. Alternatively, in the case where the request information has been received in step S703 and the association response including only the information indicating permission has been sent in step S704, the communication device 102 starts the multilink communication based on the request information received in step S703. In the present exemplary embodiment, in step S705, the communication device 102 starts the multilink communication via the multiple links established with the communication device 103.

[0227] If the communication device 102 starts the multi-link communication, then in step S706, the communication device 102 notifies the switching destination information of the multi-link communication. Specifically, the communication device 102 sends a message including Fig.10 The communication device 102 may transmit a beacon including the switching destination link information element shown in . The communication device 102 may transmit a beacon including the switching destination information at each beacon interval. In this step, in addition to the switching destination information, the communication device 102 may also transmit the capability information transmitted in step S701.

[0228] In the present exemplary embodiment, in this step, the communication device 102 transmits a beacon including the switching destination information, but the management frame to be transmitted is not limited thereto. The communication device 102 may transmit a probe response including the switching destination information. In this case, the communication device 102 determines whether a probe request has been received in the steps included between steps S705 and S706. If the communication device 102 determines that a probe request has been received, the communication device 102 performs the processing in step S706, and if the communication device 102 determines that a probe request has not been received, the communication device 102 determines again whether a probe request has been received.

[0229] The communication device 102 can send a probe response including different information based on the other device that has sent the probe request. Specifically, in the case where the communication device 102 has received a probe request sent from the other device (communication device 103 in the present exemplary embodiment) with which multi-link communication has already started, the communication device 102 sends a probe response including switching destination information. In this case, the probe response does not need to include capability information about multi-link communication. On the other hand, in the case where the communication device 102 has received a probe request sent from the other device with which multi-link communication has not yet started, the communication device 102 sends a probe response that does not include switching destination information. In this case, the probe response includes capability information about multi-link communication. By changing the information included in the probe response according to the sending device of the probe request, the amount of information to be transmitted can be reduced and the overhead can be reduced.

[0230] The communication device 102 may send a probe response including different information based on whether the received probe request includes information indicating a request for switching destination information. In the case where the communication device 102 has received a probe request including information indicating a request for switching destination information, the communication device 102 sends a probe response including the switching destination information. In this case, the probe response does not need to include capability information about multi-link communication. On the other hand, in the case where the communication device 102 has received a probe request that does not include information indicating a request for switching destination information, the communication device 102 sends a probe response that does not include switching destination information. In this case, the probe response includes capability information about multi-link communication. In this way, by changing the information included in the probe response according to whether the probe request includes information indicating a request for switching destination information, the amount of information to be transmitted can be reduced and the overhead can be reduced.

[0231] If the communication device 102 notifies the switching destination information, then in step S707, the communication device 102 determines whether to start multi-link communication with a different counterpart device. The different counterpart device refers to another communication device, and the multi-link communication with the other communication device has not yet started. In the present exemplary embodiment, the different counterpart device refers to another communication device that is different from the communication device 103. In the case where a start instruction for multi-link communication with another communication device has been issued from the user ("Yes" in step S707), the communication device 102 makes a "Yes" determination in this step and performs the processing in step S702. On the other hand, in the case where a start instruction for multi-link communication has not yet been issued from the user ("No" in step S707), the communication device 102 makes a "No" determination in this step and performs the processing in step S708.

[0232] The determination in step S707 does not need to be made based on a user instruction, and the communication device 102 may make a determination based on whether a probe request has been received from another communication device. In this case, based on receiving a probe request from another communication device with which multilink communication has not yet started, the communication device 102 makes a determination of "yes" in this step, and performs the processing in step S703. In the case where a probe request has not been received from another communication device ("no" in step S707), the communication device 102 makes a determination of "no" in this step, and performs the processing in step S708.

[0233] Alternatively, the communication device 102 may make the determination in step S707 based on whether an association request has been received from another communication device with which multilink communication has not yet started. In this case, based on receiving an association request from another communication device with which multilink communication has not yet started, the communication device 102 makes a determination of "yes" in this step and performs the processing in step S704. On the other hand, in the case where an association request has not been received from another communication device, the communication device 102 makes a determination of "no" in this step and performs the processing in step S708.

[0234] If the communication device 102 receives a change request or an association request from the communication device 103 , the communication device 102 returns a change response or an association response as a response.

[0235] Next, in step S708, the communication device 102 determines whether to change the link to be used for the multi-link communication with the communication device 103. If the communication device 102 receives a link change request from the communication device 103 ("Yes" in step S708), the communication device 102 makes a "Yes" determination in this step, and performs the processing in step S709. On the other hand, in the case where the link change request has not been received from the communication device 103 ("No" in step S708), the communication device 102 makes a "No" determination in this step, and performs the processing in step S710. Alternatively, in addition to or in place of the change request, the communication device 102 may make the determination in step S708 based on whether an association request has been received from the communication device 103. In the case where the association request has been received from the communication device 103, the communication device 102 makes a "Yes" determination in this step, and in the case where the association request has not been received, the communication device 102 makes a "No" determination in this step.

[0236] In step S709, the communication device 102 performs a link change process in the multi-link communication with the communication device 103. Specifically, the link change process refers to switching a link used for data communication in the multi-link communication with the communication device 103 to a different link that has been established with the communication device 103. In addition to this or in lieu of this, as a link to be used for data communication with the communication device 103, a different link that has been established with the communication device 103 may be used in addition to the currently used link. Alternatively, the communication device 102 may newly establish a link to be used for multi-link communication with the communication device 103. In this case, the communication device 102 may switch the link to be used for data communication with the communication device 103 from the current link to the newly established link. Alternatively, the communication device 102 may use the newly established link in addition to the current link.

[0237] The communication device 102 starts multi-link communication via the new link with the communication device 103 .

[0238] In step S710, the communication device 102 determines whether to end the multi-link communication. Specifically, the communication device 102 makes the determination in this step based on whether the link used for the multi-link communication with the communication device 103 is maintained. In the case where multiple links are maintained with the communication device 103 ("No" in step S710), the communication device 102 makes a "No" determination in this step and performs the processing in step S706. On the other hand, in the case where multiple links are not maintained with the communication device 103 ("Yes" in step S710), the communication device 102 makes a "Yes" determination in this step and ends the processing of this flow. A link that is not maintained refers to a link whose identification information is included in a disassociation frame sent from the communication device 103, or a link that has not performed communication for a predetermined time. Alternatively, in a case where one or more links are maintained with the communication device 103, the communication device 102 may make a “No” determination in step S710, and in a case where no link is maintained, the communication device 102 may make a “Yes” determination in step S710.

[0239] In step S705 and any of the subsequent steps, when the communication device 102 receives a disassociation frame from the communication device 103, the communication device 102 performs disconnection of the link. Specifically, the communication device 102 determines that the link whose identification information is included in the disassociation frame has been disconnected, and does not perform communication via the link.

[0240] In the case where the communication device 102 performs multi-link communication with multiple counterpart devices, the communication device 102 makes the determination in step S710 based on the links with all counterpart devices performing multi-link communication. In the case where multiple links are maintained with at least one counterpart device, the communication device 102 makes a "no" determination in step S710. On the other hand, in the case where multiple links are not maintained with any counterpart device, the communication device 102 makes a "yes" determination in step S710.

[0241] So far, if Figure 7 As shown in , the communication device 102 can notify the switching destination information after starting the multi-link communication with the communication device 103. By notifying the switching destination information, the communication device 103 that has acquired the switching destination information can change the link of the multi-link communication with the communication device 102. The communication device 102 can thereby prevent a decrease in the throughput of the multi-link communication with the communication device 103 and enhance communication efficiency.

[0242] In the present exemplary embodiment, the communication device 103 sends a probe request in step S706, but the communication device is not limited thereto. Another communication device different from the communication devices 102 and 103 may send a probe request to the communication device 102. The different communication device that sends the probe request is considered to have started multi-link communication with the communication device 102. In this case, the communication device 102 may send a probe response including switching destination information that varies depending on the communication device that has sent the probe request. For example, the communication device 102 may send a probe response including switching destination information in response to the probe request sent by the communication device 103, the switching destination information indicating information about the link established with the communication device 103. At this time, the probe response sent to the communication device 103 does not include switching destination information about the link established with the other communication devices. In this case, the communication device 102 sends a probe response including switching destination information about the link established with the other communication devices in response to the probe request sent by the other communication devices. The probe response to be sent to the other communication devices does not include switching destination information about the link established with the communication device 103.

[0243] In the case where the communication device 102 includes the switching destination information into the probe response, the communication device 102 may include only information about the link corresponding to the frequency channel supported by the communication device 103 based on the capability information about the multi-link communication received from the communication device 103 .

[0244] In this exemplary embodiment, the communication device 102 sends information about all links that will become the switching destination when sending the switching destination information, but the processing is not limited to this. The communication device 102 may only send information about the BSS, frequency channel or link that has been determined to have a high possibility of acquiring a transmission opportunity for the communication device 103 (STA). For example, the communication device 102 determines a BSS with a small ratio of the time when the media is busy, or a small BSS with a high priority service such as AC_VO or AC_VI as a BSS with a high possibility of acquiring a transmission opportunity for STA. The communication device 102 can similarly determine the frequency channel and link. The communication device 102 includes the BSSID of the BSS determined to have a high possibility of acquiring a transmission opportunity for STA into the BSSID field 1123. In this case, other fields of the link report can be omitted. The channel number field 1126 can be included to indicate the frequency channel used in the BSS. In the case of making a determination based on the frequency channel, only the channel number field 1126 can be included instead of the BSSID field 1123. Alternatively, a BSSID field 1123 indicating the ID of the BSS established by the communication device 102 in the corresponding frequency channel may be included. In the case where the determination is made based on the link, at least one of a channel number field 1126 indicating the frequency channel used in the corresponding link and a BSSID field 1123 indicating the BSS may be included. In this case, the communication device 102 selects an appropriate link as the switching destination of the link with the communication device 103, and then transmits information about the switching destination candidate link to the communication device 103. This reduces the processing to be performed when the communication device 103 selects a link to be used as a switching destination.

[0245] In the case where the communication device 102 performs multi-link communication, or in the case where an instruction to perform multi-link communication has been issued, the communication device 102 may include information about the multi-link communication in the MAC frame, and avoid including information about the multi-link communication in the MAC frame in other cases. In particular, when multi-link communication is not performed, by avoiding including the switching destination information in the beacon or the probe response, the frame overhead can be reduced.

[0246] In the case of indicating the switching destination information, by using a frame format defined in a standard established earlier than the IEEE 802.11ax standard, the development burden of software and hardware forming or analyzing a communication device can be reduced.

[0247] In the present exemplary embodiment, in the case where the communication device 102 performs multi-link communication, the communication device 102 includes the switching destination information in at least one of the beacon and the probe response. On the other hand, even in the case where the communication device 102 performs multi-link communication, the switching destination information is not included in the association response, disassociation, authentication, and deauthentication. By avoiding including the switching destination information in the frame to be used for establishment or disconnection of the link and the frame to be used for authentication of the other device, the communication device 102 can reduce the overhead of the frame. The communication device 102 is only required to avoid including the switching destination information in at least one of the association response, disassociation, authentication, and deauthentication.

[0248] In the present exemplary embodiment, by acquiring information about different links via a link of a multi-link communication that has been established with the communication device 102, the communication device 103 selects whether to change the link currently used for data communication with the communication device 102. In this case, link change refers to link switching. Alternatively, in place of this, a link to be used for data communication may be added. Alternatively, in the case where data communication with the communication device 102 has been performed via multiple links, the type of data to be sent via a certain link may be changed or the ratio of data to be sent may be changed. The communication device 103 acquires information about different links from the communication device 102 via a link that is desired to be changed. Alternatively, information about a link may be acquired from the communication device 102 via a link different from the link that is desired to be changed. In this case, as information about a link, information about a link used for acquisition of information may be included.

[0249] In the present exemplary embodiment, when the multilink communication ends, a disassociation frame is sent from the communication device 103 to the communication device 102, but the process is not limited thereto. A disassociation frame may be sent from the communication device 102 to the communication device 103. In this case, the communication device 103 performs Figure 7 The process in step S710 is replaced by Figure 6 In addition, the communication device 102 executes steps S609 and S610. Figure 6 The processing in steps S609 and S610 is replaced by Figure 7 Step S710.

[0250] In the present exemplary embodiment, the communication devices 102 and 103 establish multiple links, start multi-link communication, and then transmit the switching destination information. However, the processing flow is not limited to this, and the communication devices 102 and 103 may establish a single link and then transmit the switching destination information. Specifically, in Figure 6 Step S605 and Figure 7In step S705, communication via a single established link may be started instead of multi-link communication. In this case, the communication devices 102 and 103 may be connected at Figure 6 Step S608 and Figure 7 A new link is established in the link change in step S709, and multi-link communication is started.

[0251] Figure 6 and 7 At least a part or all of the processing to be performed by the communication device 102 and the communication device 103 in the flowchart shown in can be implemented by hardware. In the case of implementing the processing by hardware, it is sufficient to generate a dedicated circuit on a field programmable gate array (FPGA) from a computer program for implementing each step by using a predetermined compiler, for example, and use the dedicated circuit. In addition, the gate array circuit can be formed and implemented as hardware similarly to the FPGA. In addition, the processing can be implemented by an application-specific integrated circuit (ASIC).

[0252] The exemplary embodiments of the present invention can also be implemented by supplying a program for implementing one or more functions of the above exemplary embodiments to a system or device via a network or storage medium and one or more processors in a computer in the system or device read out the program and execute the processing of the program. In addition, the exemplary embodiments of the present invention can also be implemented by a circuit (e.g., ASIC) that implements one or more functions.

[0253] The present invention is not limited to the above embodiments and various changes and modifications can be made within the spirit and scope of the present invention. Therefore, in order to inform the public of the scope of the present invention, the following claims are made.

[0254] This application claims the benefit of Japanese Patent Application No. 2020-038139 filed on March 5, 2020, which is hereby incorporated herein by reference.

Claims

1. A communication device capable of performing multi-link communication in accordance with the Institute of Electrical and Electronics Engineers (IEEE) 802.11 series of standards, the communication device comprising: an establishing unit, the establishing unit being configured to establish a link with other communication devices via a frequency channel; as well as A communication unit configured to transmit a media access control (MAC) frame in which information about a second link with the other communication device is included after a field in which information about a service set identifier (SSID) is stored, and the second link with the other communication device is different from the first link established by the establishing unit. 2 . The communication device according to claim 1 , wherein the MAC frame is a beacon or a probe response. 3 . The communication device according to claim 1 , wherein the second link is a link that the establishing unit has established with the other communication device. 4 . The communication device according to claim 1 , wherein the second link is a link that can be established by the establishing unit and the other communication device. 5 . The communication device according to claim 1 , wherein the information about the second link includes information indicating a ratio of a period during which a frequency channel used by the second link is busy relative to a predetermined period.

6. The communication device according to claim 1, wherein the information about the second link includes information indicating power of a signal received by the transmitting device of the MAC frame from the receiving device of the MAC frame in a frequency channel used by the second link. 7 . The communication device according to claim 1 , wherein the information about the second link includes information indicating a frequency channel used by the second link. 8 . The communication device according to claim 1 , wherein the information about the second link includes information indicating a signal-to-noise ratio about a frequency channel used by the second link.

9. The communication device according to claim 1, wherein the information about the second link includes information indicating the number of communication devices supporting wireless communication conforming to the IEEE 802.11be standard existing in a wireless network to which the transmission device of the MAC frame belongs.

10. The communication device according to claim 1, wherein the information about the second link includes identification information about the second link.

11. The communication device according to claim 10, wherein the identification information is a basic service set identifier (BSSID) about the second link. The communication device according to claim 10 , wherein the identification information is an identifier of the second link.

13. The communication device according to claim 1, wherein the information about the second link is included in a neighbor report element conforming to the IEEE 802.11 series of standards.

14. The communication device of claim 1, wherein the information about the second link is included after an Extremely High Throughput (EHT) capability element in the MAC frame. 15 . The communication device according to claim 1 , wherein the information about the second link is included after a HE 6 GHz band capability field in the MAC frame.

16. The communication device according to claim 1, wherein the communication device further comprises a control unit configured to control data communication with the other communication device via the first link based on information about the second link in a case where the MAC frame has been received.

17. The communication device according to claim 1, wherein the first link and the second link are links using different frequency channels.

18. The communication device according to claim 1, wherein the communication unit transmits at least one of an association response, a disassociation, an authentication, and a deauthentication with the other communication device, and the association response, the disassociation, the authentication, and the deauthentication do not include information about the second link.

19. A communication method capable of performing multi-link communication in accordance with the Institute of Electrical and Electronics Engineers (IEEE) 802.11 series standards, the communication method comprising: establishing a link between the communication device and other communication devices via a frequency channel; as well as A media access control (MAC) frame is transmitted between the communication device and the other communication device, in which information about a second link is included after a field in which information about a service set identifier (SSID) is stored, and the second link is different from the first link established in the establishment.

20. A storage medium for storing a program for causing a computer to function as each unit of the communication device according to claim 1.

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