COMMUNICATION DEVICE, COMMUNICATION METHOD, AND PROGRAM

Abstract

To enable communication of information on communication via multiple Links established in multiple different frequency channels and conforming to the IEEE 802.11 series standard by using an appropriate MAC frame with the other device.SOLUTION: A communication device 102 or a communication device 103 communicates a wireless frame conforming to the IEEE 802.11 series standard with the other device, and a media access control (MAC) frame of the wireless frame includes information indicating a frequency channel as information on communication via multiple links conforming to the IEEE 802.11 series standard established in a plurality of different frequency channels capable of performing wireless communication conforming to the IEEE 802.11 series standard between a device that has transmitted the wireless frame and the other device.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to the transmission and reception of information regarding communication in wireless communication. [Background technology]

[0002] The IEEE802.11 series is known as a WLAN communication standard established by the IEEE (Institute of Electrical and Electronics Engineers). WLAN is an abbreviation for Wireless Local Area Network. The IEEE802.11 series standards include the IEEE802.11a / b / g / n / ac / ax standards.

[0003] Patent Document 1 discloses that the IEEE802.11ax standard performs wireless communication using Orthogonal Frequency Division Multiple Access (OFDMA). The IEEE802.11ax standard achieves high peak throughput by performing wireless communication using OFDMA.

[0004] In order to further improve throughput and frequency utilization efficiency, IEEE is considering the formulation of the IEEE802.11be standard as a new standard in the IEEE802.11 series. The IEEE802.11be standard considers technology that enables one AP (Access Point) to establish multiple links with one STA (Station) via multiple different frequency channels for communication. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2018-50133 A Summary of the Invention [Problem to be solved by the invention]

[0006] Thus, the IEEE802.11be standard considers Multi-Link communication, in which an AP and a STA establish multiple links with different frequency channels and communicate in parallel. To perform Multi-Link communication, it is necessary to communicate information related to Multi-Link communication between the AP and the STA, such as the AP's Multi-Link communication capability information. Previously, there was no MAC (Media Access Control) frame for appropriately communicating information related to Multi-Link communication.

[0007] In view of the above problems, the present invention aims to enable communication of information regarding communication via multiple links compliant with the IEEE 802.11 series standards established between a partner device and multiple different frequency channels using an appropriate MAC frame. [Means for solving the problem]

[0008] In order to achieve the above object, the communication device of the present invention is a communication device conforming to the IEEE 802.11 series standard. MAC (Media Access Control) Frame General Reliable means of communication and an establishment means for establishing a plurality of links, each of which has a different frequency channel, with another communication device. having A predetermined MAC Frames using the multiple links Regarding communication Minimum Frequency Spacing Information showing Fields that can indicate The present invention is characterized in that it includes: Effect of the Invention

[0009] According to the present invention, information regarding communications via a plurality of links compliant with the IEEE802.11 series standards established with a partner device on a plurality of different frequency channels can be communicated using an appropriate MAC frame. [Brief description of the drawings]

[0010] [Figure 1]FIG. 1 is a diagram showing a configuration of a network to which a communication device 102 belongs. [Diagram 2] FIG. 2 is a diagram illustrating a hardware configuration of a communication device 102. [Diagram 3] FIG. 2 is a diagram illustrating a functional configuration of a communication device 102. [Figure 4] 10 is a sequence diagram showing an example of a process executed when the communication device 102 and the communication device 103 perform Multi-Link communication. [Diagram 5] FIG. 13 is a diagram illustrating an example of a frame format of a Multi-Link Capability Element. [Figure 6] 11 is a flowchart showing a process executed by the communication device 103 when performing Multi-Link communication. [Figure 7] 10 is a flowchart showing a process executed by the communication device 102 when performing Multi-Link communication. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] Hereinafter, an embodiment of the present invention will be described in detail with reference to the accompanying drawings. Note that the configurations shown in the following embodiments are merely examples, and the present invention is not limited to the illustrated configurations.

[0012] FIG. 1 shows the configuration of a network in which a communication device 102 according to this embodiment participates. The communication device 102 is an access point (AP) that has a role of constructing a network 101. The network 101 is a wireless network. In this embodiment, when the communication device 102 constructs multiple networks, it is assumed that the BSSIDs of the networks are all the same. It is assumed that BSSID is an abbreviation for Basic Service Set Identifier and is an identifier for identifying a network. It is also assumed that the SSIDs indicated by the communication device 102 in each network are all common. It is assumed that SSID is an abbreviation for Service Set Identifier and is an identifier for identifying an access point. In this embodiment, the communication device 102 uses one SSID even when multiple connections are established.

[0013] Moreover, the communication device 103 is a station (STA) that has a role of participating in the network 101. Each communication device is compatible with the IEEE802.11be (EHT) standard and can execute wireless communication conforming to the IEEE802.11be standard via the network 101. Note that IEEE is an abbreviation for Institute of Electrical and Electronics Engineers. Also, EHT is an abbreviation for Extremely High Throughput. Note that EHT may be interpreted as an abbreviation for Extreme High Throughput. Each communication device can communicate in the frequency bands of 2.4 GHz, 5 GHz, and 6 GHz. The frequency bands used by each communication device are not limited to these, and a different frequency band such as the 60 GHz band may be used. Also, each communication device can communicate using bandwidths of 20 MHz, 40 MHz, 80 MHz, 160 MHz, and 320 MHz.

[0014] The communication devices 102 and 103 can realize multi-user (MU) communication in which signals of multiple users are multiplexed by performing OFDMA communication conforming to the IEEE802.11be standard. OFDMA communication is an abbreviation for Orthogonal Frequency Division Multiple Access. In OFDMA communication, a part of the divided frequency band (RU, Resource Unit) is assigned to each STA so as not to overlap, and the carriers assigned to each STA are orthogonal. Therefore, the AP can communicate with multiple STAs in parallel.

[0015] Moreover, the communication devices 102 and 103 perform multi-link communication by establishing links via multiple frequency channels and communicating. Here, the frequency channel is a frequency channel defined in the IEEE802.11 series standard, and refers to a frequency channel capable of performing wireless communication conforming to the IEEE802.11 series standard. In the IEEE802.11 series standard, multiple frequency channels are defined in each of the 2.4 GHz, 5 GHz, and 6 GHz frequency bands. In addition, in the IEEE802.11 series standard, the bandwidth of each frequency channel is defined as 20 MHz. Note that a bandwidth of 40 MHz or more may be used in one frequency channel by bonding with an adjacent frequency channel. For example, the communication device 102 can establish a first link 104 via a first frequency channel in the 2.4 GHz band and a second link 105 via a second frequency channel in the 5 GHz band with the communication device 103, and communicate via both links. In this case, the communication device 102 maintains the second link 105 via the second frequency channel in parallel with the first link 104 via the first frequency channel. In this way, the communication device 102 can improve the throughput of the communication with the communication device 103 by establishing links with the communication device 103 via multiple frequency channels. Note that the communication devices 102 and 103 may establish multiple links with different frequency bands in the multi-link communication. For example, the communication devices 102 and 103 may establish a third link in the 6 GHz band in addition to the first link 104 in the 2.4 GHz band and the second link 105 in the 5 GHz band. Alternatively, links may be established via multiple different channels included in the same frequency band. For example, the first link 104 via 1ch in the 2.4 GHz band and the second link 105 via 5ch in the 2.4 GHz band may be established. Note that links with the same frequency band and links with different frequency bands may be mixed.For example, the communication devices 102 and 103 may establish a first link 104 via 1ch in the 2.4GHz band, a second link 105 via 5ch in the 2.4GHz band, and a third link via 36ch in the 5GHz band. By establishing multiple connections with the communication device 103 using different frequency bands, the communication device 102 can communicate with the communication device 103 using the other band even when one band is congested, thereby preventing a decrease in throughput in communication with the communication device 103.

[0016] In multi-link communication, the multiple links established between the communication devices 102 and 103 need only have different frequency channels. Note that in multi-link communication, the channel spacing between the frequency channels of the multiple links established between the communication devices 102 and 103 needs only to be greater than 20 MHz. Note that, in this 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.

[0017] The communication devices 102 and 103 can execute three modes of communication as multi-link communication. One is asynchronous mode (async mode), in which communication through each link in multi-link communication is performed asynchronously. Specifically, communication through the first link and communication through the second link are performed at independent timings. Therefore, both the first link and the second link can communicate at a timing that is not related to the timing of communication of the other link. In this case, if the channel interval between the frequency channels (channels) used in each link is narrow, communication of one link affects communication of the other link. Specifically, if the frequency channels of the links are close to each other, the other link detects communication performed in one link by carrier sense, and therefore communication of the other link cannot be performed while communication is being performed in one link. Therefore, in async mode, the channel interval between the links is wide. The other mode is synchronous mode (sync mode), in which communication through multiple links is performed synchronously. Specifically, the first link and the second link start communication at the same timing. In this case, the communication through each link starts at the same time, and the communication through one link is not carrier-sensed by the other link, so the channel interval between the channels used by each link may be narrow. There is also another mode called Semi-Asynchronous Mode (Semi-Async Mode). In this mode, when data communication is performed through one link, if the frequency channel of the other link is free, the communication through both links is performed in synchronization. For example, if the back-off counter of the first link becomes 0 and the frequency channel of the second link is free, the communication through the first link and the second link start at the same timing. In this case, the back-off counter of the second link does not need to be 0.When the backoff counter of the first link becomes 0, if the frequency channel of the second link is not available, only communication via the first link is started, and communication via the second link is not started. In this mode, when communication via multiple links is performed in parallel, the communication via each link is started simultaneously, so the interval between the channels used by each link may be narrow. The communication devices 102 and 103 may select the mode to be used in the multi-link communication based on the channel intervals of the established multiple links.

[0018] When performing multi-link communication, at least one of the communication devices 102 and 103 is a device that can simultaneously transmit data via a certain link and receive data via another link. Alternatively, at least one of the communication devices 102 and 103 may be a device that can simultaneously only transmit data via another link when transmitting data via a certain link. Alternatively, at least one of the communication devices 102 and 103 may be a device that can simultaneously only receive data via another link when receiving data 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 communicate data via another link when communicating data via a certain link. Note that such communication devices are not compatible with Sync Mode or Semi-Async Mode.

[0019] When performing multi-link communication, the communication devices 102 and 103 divide one piece of data and transmit it to the other device via multiple links. Alternatively, the communication devices 102 and 103 may transmit the same data via each of the multiple links, so that the communication via one link serves as a backup communication for the communication via the other link. Specifically, the communication device 102 transmits the same data to the communication device 103 via a first link via a first frequency channel and a second link via a second frequency channel. In this case, even if an error occurs in the communication via the first link, the communication device 103 can receive the data transmitted from the communication device 102 because the same data is transmitted via the second link. Alternatively, the communication devices 102 and 103 may use different links depending on the type of frame or the type of data to be communicated. For example, the communication device 102 may transmit a management frame via the first link and transmit a data frame including data via the second link. Specifically, management frames refer to Beacon frames, Probe Request frames / Response frames, and Association Request frames / Response frames. In addition to these frames, Disassociation frames, Authentication frames, De-Authentication frames, and Action frames are also called management frames. Beacon frames are frames that report network information. Probe Request frames are frames that request network information, and Probe Response frames are the corresponding responses, providing network information. Association Request frames are frames that request a connection, and Association Response frames are the corresponding responses, indicating permission for connection or an error. Disassociation frames are frames that cut off a connection.An authentication frame is a frame that authenticates a partner device, and a de-authentication frame is a frame that interrupts authentication of a partner device and disconnects the connection. An action frame is a frame for performing additional functions other than those described above. The communication devices 102 and 103 transmit and receive management frames that comply with the IEEE802.11 series standards. Alternatively, when the communication device 102 transmits data related to a captured image, for example, meta-information such as date, parameters at the time of capturing an image (aperture value and shutter speed), and location information may be transmitted via a first link, and pixel information may be transmitted via a second link.

[0020] Furthermore, the communication devices 102 and 103 may be capable of performing MIMO (Multiple-Input And Multiple-Output) communication. In this case, the communication devices 102 and 103 have multiple antennas, and one of them transmits different signals from each antenna using the same frequency channel. The receiving side simultaneously receives all signals arriving from multiple streams using multiple antennas, and separates and decodes the signals of each stream. In this way, by performing MIMO communication, the communication devices 102 and 103 can communicate more data in the same time compared to when not performing MIMO communication. Furthermore, the communication devices 102 and 103 may perform MIMO communication in some links when performing multi-link communication.

[0021] Although the communication devices 102 and 103 are described as being compatible with the IEEE802.11be standard, they may also be compatible with at least one of the legacy standards that are standards prior to the IEEE802.11be standard. The legacy standards are the IEEE802.11a / b / g / n / ac / ax standards. In this embodiment, at least one of the IEEE802.11a / b / g / n / ac / ax / be standards is called the IEEE802.11 series standard. In addition to the IEEE802.11 series standard, they may also be compatible with other communication standards such as Bluetooth (registered trademark), NFC, UWB, Zigbee, and MBOA. UWB stands for Ultra Wide Band, and MBOA stands for Multi Band OFDM Alliance. OFDM stands for Orthogonal Frequency Division Multiplexing. NFC stands for Near Field Communication. UWB includes wireless USB, wireless 1394, WiNet, etc. It may also be compatible with communication standards for wired communication such as wired LAN.

[0022] Specific examples of the communication device 102 include, but are not limited to, a wireless LAN router and a PC. The communication device 102 may be any communication device capable of executing Multi-Link communication with other communication devices. The communication device 102 may be an information processing device such as a wireless chip capable of executing wireless communication conforming to the IEEE802.11be standard. Specific examples of the communication device 103 include, but are not limited to, a camera, a tablet, a smartphone, a PC, a mobile phone, a video camera, and the like. The communication device 103 may be any communication device capable of executing Multi-Link communication with other communication devices. The communication device 103 may be an information processing device such as a wireless chip capable of executing wireless communication conforming to the IEEE802.11be standard. The network in FIG. 1 is a network configured by one AP and one STA, but the number of APs and STAs is not limited to this. The information processing device such as a wireless chip has an antenna for transmitting the generated signal.

[0023] 2 shows a hardware configuration of the communication device 102 in this embodiment. 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.

[0024] The storage unit 201 is composed of one or more memories such as a ROM and a RAM, and stores various information such as computer programs for performing various operations described below and communication parameters for wireless communication. ROM stands for Read Only Memory, and RAM stands for Random Access Memory. As the storage unit 201, in addition to memories such as ROM and RAM, storage media such as flexible disks, hard disks, optical disks, magneto-optical disks, CD-ROMs, CD-Rs, magnetic tapes, non-volatile memory cards, and DVDs may be used. Furthermore, the storage unit 201 may include multiple memories.

[0025] The control unit 202 is configured with one or more processors such as a CPU or an MPU, and controls the entire communication device 102 by executing a computer program stored in the storage unit 201. The control unit 202 may control the entire communication device 102 in cooperation with the computer program stored in the storage unit 201 and an OS (Operating System). The control unit 202 also generates data and signals (radio frames) to be transmitted in communication with other communication devices. The CPU stands for Central Processing Unit, and the MPU stands for Micro Processing Unit. The control unit 202 may also include multiple processors such as multi-core processors, and the entire communication device 102 may be controlled by the multiple processors.

[0026] Furthermore, the control unit 202 controls the functional unit 203 to execute predetermined processes such as wireless communication, imaging, printing, projection, etc. The functional unit 203 is hardware that enables the communication device 102 to execute predetermined processes.

[0027] The input unit 204 receives various operations from the user. The output unit 205 performs various outputs to the user via a monitor screen or a speaker. Here, the output by the output unit 205 may be a display on a monitor screen, a voice output by a speaker, a vibration output, or the like. Note that both the input unit 204 and the output unit 205 may be realized by one module, such as a touch panel. Also, the input unit 204 and the output unit 205 may be integrated with the communication device 102, or may be separate.

[0028] The communication unit 206 controls wireless communication conforming to the IEEE802.11be standard. The communication unit 206 may control wireless communication conforming to other IEEE802.11 series standards in addition to the IEEE802.11be standard, or control wired communication such as wired LAN. The communication unit 206 controls the antenna 207 to transmit and receive signals for wireless communication generated by the control unit 202. If the communication device 102 supports the NFC standard, Bluetooth standard, or the like in addition to the IEEE802.11be standard, the communication unit 206 may control wireless communication conforming to these communication standards. If the communication device 102 can perform wireless communication conforming to a plurality of communication standards, the communication unit 206 may have a configuration having a communication unit and an antenna corresponding to each communication standard. The communication device 102 communicates data such as image data, document data, and video data with the communication device 103 via the communication unit 206. The antenna 207 may be configured as a separate unit from the communication unit 206, or may be configured as a single module together with the communication unit 206.

[0029] The antenna 207 is an antenna capable of communication in the 2.4 GHz band, the 5 GHz band, and the 6 GHz band. In this embodiment, the communication device 102 has one antenna, but may have a different antenna for each frequency band. In addition, when the communication device 102 has multiple antennas, it may have a communication unit 206 corresponding to each antenna.

[0030] The communication device 103 has the same hardware configuration as the communication device 102 .

[0031] 3 shows the functional configuration of the communication device 102 in this embodiment. The communication device 102 is composed of a Multi-Link communication capability information generation unit 301, a Multi-Link communication operation information determination unit 302, and a connection processing unit 304. In addition to these, the communication device 102 is also composed of a MAC (Media Access Control) frame generation unit 305 and a data transmission / reception unit 306.

[0032] Capability information generating unit 301 is a block that generates capability information related to Multi-Link communication of communication device 102. Communication device 102 generates capability information for notifying other communication devices of its own capability related to Multi-Link communication. Capability information related to Multi-Link communication will be described later with reference to FIG. 5. Note that the capability information may be notified of the capability information of the own device to other communication devices, or it may simply be received from other communication devices of capability information of the other device.

[0033] The operation information determination unit 302 is a block that determines operation information regarding Multi-Link communication with a partner device based on capability information regarding Multi-Link communication of the device itself and the partner device. Operation information regarding Multi-Link communication refers to the frequency channel and bandwidth used in communication executed as Multi-Link communication between the communication devices 102 and 103. Details of the operation information regarding Multi-Link communication will be described later with reference to FIG. 5. The determined operation information may or may not be notified to the partner device.

[0034] The connection processing unit 304 is a block that performs processing for allowing the communication device 103, which is 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, which is a connection request received from the communication device 103. The communication device 102 has a connection processing unit 304 corresponding to each of a plurality of Links that the communication device 102 establishes.

[0035] The MAC frame generating unit 305 is a block that generates a MAC frame including information indicating capability information related to Multi-Link communication generated by the capability information generating unit 301 and operational information related to Multi-Link communication determined by the operational information determining unit 302. The MAC frame generated by the MAC frame generating unit 305 is transmitted by being included in at least one of the wireless frames of a Beacon, a Probe Response, and an Association Response. In addition to this, or instead, the generated MAC frame is transmitted by being included in a Reassociation Response. The capability information and operational information included in the MAC frame generated by the MAC frame generating unit 305 are indicated by an Element shown in FIG. 5, which will be described later.

[0036] The data transmitter / receiver unit 306 is a block that transmits and receives data frames in Multi-Link communication based on the operation information related to Multi-Link communication determined by the operation information determination unit 302. The data transmitter / receiver unit 306 may transmit a wireless frame including a MAC frame generated by the MAC frame generation unit 305 and receive a wireless frame from a partner device.

[0037] The communication device 103 has the same functional configuration as the communication device 102, but differs in the following respects.

[0038] The communication device 103 has a request information determination unit 302 instead of the operation information determination unit 302. This is a block that determines request information regarding Multi-Link communication with a partner device based on capability information regarding Multi-Link communication of the own device and the partner device. The request information regarding Multi-Link communication refers to a frequency channel, a bandwidth, and the like that are requested to be used in communication executed as Multi-Link communication between the communication devices 102 and 103. Details of the request information regarding Multi-Link communication will be described later with reference to FIG. 5. Regarding the request information, the partner device may or may not be notified of the determined request information.

[0039] The connection processing unit 304 is a block that performs processing for the communication device 103 to join the network 101 established by the communication device 102 that is an AP. Specifically, the connection processing unit 304 causes the communication device 103 to transmit an Association Request, which is a connection request, to the communication device 102, and to receive an Association Response as a response from the communication device 102.

[0040] Further, the MAC frame generating unit 305 is a block that generates a MAC frame including information indicating capability information related to Multi-Link communication generated by the capability information generating unit 301 and request information related to Multi-Link communication determined by the request information determining unit 302. The MAC frame generated by the MAC frame generating unit 305 is transmitted by being included in at least one of a Probe Request, an Association Request, and a Reassociation Request wireless frame. The capability information and request information included in the MAC frame generated by the MAC frame generating unit 305 are indicated by an Element shown in FIG. 5, which will be described later.

[0041] FIG. 4 is a sequence diagram showing an example of processing executed when the communication device 102 and the communication device 103 perform Multi-Link communication.

[0042] The communication devices 102 and 103 each have a connection processing unit 304 internally corresponding to each of a plurality of links. AP1 of the communication device 102 is a connection processing unit 304 for the first link, and AP2 is a connection processing unit 304 for the second link. Also, STA1 of the communication device 103 shows a connection processing unit 304 for the first link, and STA2 shows a connection processing unit 304 for the second link. STA1 and AP1 process communication via a first frequency channel (e.g., 1ch in the 2.4 GHz band). STA2 and AP2 process communication via a second frequency channel (e.g., 36ch in the 5 GHz band).

[0043] The process of this sequence is started in response to the power being turned on for each of the communication devices 102 and 103. Alternatively, at least one of the communication devices 102 and 103 may start the process in response to an instruction to start Multi-Link communication from a user or an application. Alternatively, at least one of the communication devices 102 and 103 may start the process in response to the amount of data to be communicated with the other device reaching or exceeding a predetermined threshold.

[0044] First, the communication device 102 transmits a Beacon including its own network information on a first frequency channel to notify surrounding STAs of the network information (S401). Specifically, the network information is a transmission interval at which the communication device 102 transmits a beacon and the SSID of the communication device 102. In addition, the communication device 102 may include a Multi-Link Capability Element shown in Fig. 5, which will be described later, in the Beacon as network information to notify capability information related to the Multi-Link communication of the communication device 102.

[0045] When the communication device 103 receives a Beacon from the communication device 102 transmitted on the first frequency channel, the communication device 103 transmits a Probe Request on the first frequency channel to inquire about network information of the communication device 102 (S402). The Probe Request includes the SSID of the communication device 103. In addition to this, the communication device 103 may notify capability information related to Multi-Link communication of the communication device 103 by including a Multi-Link Capability Element shown in Fig. 5 described later in the Probe Request.

[0046] When the communication device 102 receives the Probe Request, it transmits a Probe Response to the communication device 103 in the first frequency channel as a response (S403). If the communication device 102 does not include the Multi-Link Capability Element shown in Fig. 5 in the Beacon, it transmits the Probe Response by including the Element. Alternatively, the communication device 102 may include only a part of the information included in the Multi-Link Capability Element shown in Fig. 5 described later in the Beacon, and include the remaining information or all of the information in the Probe Response.

[0047] By performing the processes of S401 to S403, the communication devices 102 and 103 can exchange capability information regarding their respective Multi-Link communications.

[0048] Next, the communication device 103 transmits an Association Request, which is a connection request, to the communication device 102 on the first frequency channel. In this case, the communication device 103 may notify the communication device 102 of capability information related to the Multi-Link communication by including the Multi-Link Capability Element shown in FIG. 5 in the Association Request. The communication device 103 may determine capability information to be transmitted in S404 based on capability information related to the Multi-Link communication of the communication device 102 acquired in at least one of S401 and S403. For example, even if the communication device 103 can combine Links in the 2.4 GHz band and the 5 GHz band in the Multi-Link communication, the communication device 102 only supports multiple Links in the 2.4 GHz band. In this case, the communication device 103 may transmit only capability information related to the establishment of multiple Links in the 2.4 GHz band as capability information to be transmitted in this step. In this embodiment, the communication device 103 transmits capability information related to the Multi-Link communication of the device itself in S402, but the present invention is not limited to this, and the capability information may not be transmitted in S402, but may be transmitted only in this step. Alternatively, the communication device 103 may transmit request information requested when performing Multi-Link communication, instead of capability information, by including a Multi-Link Capability Element shown in Fig. 5 in the Association Request. The request information requested by the communication device 103 may be indicated by the Multi-Link Capability Element in Fig. 5, or may be indicated by another element. Details of the request information will be described later with reference to Fig. 5.

[0049] When the communication device 102 receives the Association Request, it transmits an Association Response to the communication device 103 in response on the first frequency channel (S405). The Association Response transmitted here includes a Multi-Link Capability Element that indicates operation information determined by the communication device 102 when performing Multi-Link communication with the communication device 103. Note that the operation information may be indicated by an element different from the Multi-Link Capability Element. Furthermore, if the communication device 103, which is the STA, has transmitted an Association Request including the operation information requested in S404, the communication device 102 may transmit an Association Response that includes only the approval or disapproval of the request.

[0050] If the communication device 103 can execute Multi-Link communication based on the operation information included in the Association Response, the communication devices 102 and 103 establish a link via the first frequency channel and start data communication (S406). In this case, if the operation information transmitted by the communication device 102 includes operation information for a link via the second frequency channel, the communication devices 102 and 103 also establish a link via the second frequency channel and start data communication (S407).

[0051] Note that the process of S406 is also performed when the communication device 102 indicates permission in S405 for the request information requested in S404 to the communication device 103. In addition, when the request information transmitted by the communication device 103 in S404 also includes request information related to a link via the second frequency channel, the process of S407 is performed.

[0052] In this embodiment, two links are established by transmitting and receiving frames on one frequency channel, but the present invention is not limited to this, and three or more links may be established.

[0053] In the present embodiment, the case where the multi-link communication is started when a link has not yet been established between the communication devices 102 and 103 has been shown, but the present invention is not limited to this. The communication devices 102 and 103 may start the multi-link communication by establishing a new link in addition to the already established link. In this case, the communication device 103, which is an STA, may start from the process of S404 when it has already acquired the capability information related to the multi-link communication of the communication device 102, which is an AP. Alternatively, the communication device 102 may start from the process of S404 by transmitting a signal to the communication device 103 to transmit an Association Request when it has already acquired the capability information related to the multi-link communication of the communication device 103. Alternatively, the communication devices 102 and 103 may establish a new link in addition to the multiple links that have already been established. In this case, the sequence of FIG. 4 may also start from S404.

[0054] In the present embodiment, a case where a link is established via a plurality of frequency channels by transmitting and receiving a frame in one frequency channel has been shown, but the present invention is not limited to this. When performing multi-link communication, the communication devices 102 and 103 may disconnect a link already established via a plurality of frequency channels by transmitting and receiving a frame via one frequency channel. For example, it is assumed that the communication devices 102 and 103 establish a first link via a first frequency channel and a second link via a second frequency channel and perform multi-link communication. In this case, it is assumed that either the communication device 102 or 103 transmits a disassociation, which is a link disconnection request, to the other device via the first link. If the transmitted disassociation includes information on the second link, the communication devices 102 and 103 disconnect not only the first link but also the second link. In this way, the communication devices 102 and 103 may disconnect not only the link for which the disassociation was transmitted and received, but also other links indicated by the information included in the disassociation, by transmitting and receiving the disassociation. Note that the communication devices 102 and 103 may simultaneously disconnect three or more links. Furthermore, when the disassociation includes information about a link different from the link through which the disassociation was transmitted or received, the communication devices 102 and 103 may disconnect only the other link. In this case, the communication devices 102 and 103 do not disconnect the link through which the disassociation was transmitted or received.

[0055] As described above, as shown in Fig. 4, the communication devices 102 and 103 can control the establishment or disconnection of links in other frequency channels by transmitting and receiving frames via a certain frequency channel (or link). Also, the communication devices 102 and 103 can control the establishment or disconnection of links in multiple frequency channels by transmitting and receiving frames via a certain frequency channel (or link).

[0056] Fig. 5 is a diagram showing an example of a frame format of a Multi-Link Capability Element. Note that, in this embodiment, the name of the element shown in Fig. 5 is Multi-Link Capability Element, but is not limited thereto and may be another name such as Multi-Link Element.

[0057] The communication devices 102 and 103 can notify the other device of capability information indicating the capability of the device in Multi-Link communication by using the Multi-Link Capability Element shown in Fig. 5. Also, the communication device 102 can notify the other device of operation information when performing Multi-Link communication in addition to or instead of the capability information by using the Multi-Link Capability Element shown in Fig. 5. Also, the communication device 103 can notify the other device of request information when performing Multi-Link communication in addition to or instead of the capability information by using the Multi-Link Capability Element shown in Fig. 5.

[0058] The Multi-Link Capability Element shown in FIG. 5 includes an Element ID 501, a Length 502, and ML (Multi-Link) Capabilities 503. The Element ID 501 is an identifier for identifying an Information Element, and in this embodiment, includes an identifier indicating a Multi-Link Capability Element. The Length 502 is a field indicating the data length of an Element, and in this embodiment, includes information indicating the data length of ML Capabilities 503. The ML Capabilities 503 is information specific to the Multi-Link Capability Element, and includes information related to Multi-Link communication. Details of the information included in the ML Capabilities 503 will be described later.

[0059] The communication devices 102 and 103 generate the Multi-Link Capability Elements shown in FIG. 5 in order starting from Element ID 501, and transmit them to other communication devices. In this case, the communication devices 102 and 103 generate all fields in the frame before transmitting. Specifically, the communication devices 102 and 103 generate all of Element ID 501, Length 502, and ML Capabilities 503 before transmitting them to other communication devices. Alternatively, the communication devices 102 and 103 may generate and transmit fields in parallel. Specifically, the communication devices 102 and 103 may transmit, for example, the generated Element ID 501 and Length 502 in parallel.

[0060] The communication device 102, which is an AP, adds a MAC frame including a Multi-Link Capability Element to wireless frames such as a Beacon and a Probe Response and transmits the MAC frame. In addition to these wireless frames, the communication device 102 can also add a MAC frame including this Element to wireless frames such as an Association Response and a Reassociation Response. The communication device 103, which is an STA, adds a MAC frame including a Multi-Link Capability Element to wireless frames such as a Probe Request and an Association Request and transmits the MAC frame. In addition to these wireless frames, the communication device 103 can also add a MAC frame including this Element to a Reassociation Request.

[0061] ML Capabilities 503 includes Common Info 511, Per Band Info 512, and Per Link Info 513. Common Info 511 is a field indicating information common to all frequency bands and links. Per Band Info 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 Info 513 is a field indicating information for each link.

[0062] Common Info 511 includes Primary Ch 521, Sync Mode Support 522, Async Mode Support 523, and Semi-Async Mode Support 528. Common Info 511 further includes Total Max Link Number 524, Band Combination Info 525, and Per Band Info Number 526. Common Info 511 further includes Per Link Info Number 527, and Device Type 529.

[0063] The Primary CH 521 is a field including information indicating a frequency channel for transmitting and receiving management frames related to Multi-Link communication. The Primary CH is a frequency channel used for transmitting and receiving management frames when connecting and disconnecting a link in Multi-Link communication. Specifically, information indicating a frequency channel for transmitting and receiving a Beacon including a Multi-Link Capability Element is included. The communication device 102, which is an AP, includes information indicating a frequency channel for transmitting and receiving a Beacon including a Multi-Link Capability Element. The communication device 103, which is an STA, includes information indicating a frequency channel for receiving a Beacon including a Multi-Link Capability Element (i.e., for transmitting a Probe Request including the Element). In this embodiment, information indicating a first frequency channel for transmitting and receiving a Beacon or a Probe Request / Response in FIG. 4 is included. Note that if the frequency channel for transmitting and receiving management frames is changed after the communication devices 102 and 103 start Multi-Link communication, the Primary CH 521 includes information on the frequency channel corresponding to the change. It should be noted that Primary CH 521 includes information indicating the frequency channel in which the management frame is transmitted and received, regardless of whether the element indicates capability information, operational information, or request information.

[0064] Sync Mode Support 522 is a field that includes capability information indicating whether the communication device 102 or 103 that transmits the Element supports Sync Mode for Multi-Link communication. For example, if this field contains 0, the transmitting device of the Element does not support Sync Mode, and if it contains 1, it supports Sync Mode.

[0065] When the operation information is indicated by the Multi-Link Capability Element, the Sync Mode Support 522 may indicate whether or not to execute the Sync Mode of the Multi-Link communication. For example, when the communication device 102 transmits an Association Response including this Element, this field indicates whether or not to execute the Sync Mode in the communication of the Link established by the exchange of this association. In this case, for example, when this field contains 0, it indicates that the Multi-Link communication in the Sync Mode is not executed, and when this field contains 1, it indicates that the Multi-Link communication in the Sync Mode is executed.

[0066] Alternatively, when request information is indicated by the Multi-Link Capability Element, Sync Mode Support 522 may indicate whether or not to request execution of Sync Mode in Multi-Link communication. For example, when the communication device 103, which is an STA, transmits an Association Request including this element, this field indicates whether or not the communication device 103 requests execution of Sync Mode in Multi-Link communication. For example, when this field contains 0, it indicates that execution of Multi-Link communication in Sync Mode is not requested, and when this field contains 1, it indicates that execution of Multi-Link communication in Sync Mode is requested.

[0067] Async Mode Support 523 is a field that includes capability information indicating whether the communication device 102 or 103 that transmits the Element supports the Async Mode of Multi-Link communication. For example, if this field includes 0, the transmitting device of the Element does not support the Async Mode, and if this field includes 1, it indicates that the transmitting device supports the Async Mode.

[0068] In addition, when the operation information is indicated by the Multi-Link Capability Element, the Async Mode Support 523 may indicate whether or not the Async Mode of the Multi-Link communication is executed. For example, when the communication device 102 transmits an Association Response including this Element, this field indicates whether or not the Async Mode is executed in the Link established by the exchange of this association. In this case, for example, when this field contains 0, it indicates that the Multi-Link communication in the Async Mode is not executed, and when this field contains 1, it indicates that the Multi-Link communication in the Async Mode is executed. In addition, when the operation information is indicated by the Element, if the Sync Mode Support 522 indicates that the Sync Mode is executed, this field indicates that the Async Mode is not executed. Similarly, when the Sync Mode Support 522 indicates that the Sync Mode is not executed, the Async Mode Support 523 indicates that the Async Mode is executed.

[0069] Alternatively, when request information is indicated by the Multi-Link Capability Element, Async Mode Support 523 may indicate whether or not to request execution of Async Mode in Multi-Link communication. For example, when the communication device 103, which is an STA, transmits an Association Request including this element, this field indicates whether or not the communication device 103 requests execution of Async Mode in Multi-Link communication. For example, when this field contains 0, it indicates that execution of Multi-Link communication in Async Mode is not requested, and when this field contains 1, it indicates that execution of Multi-Link communication in Async Mode is requested.

[0070] Semi-Async Mode Support 528 is a field that includes capability information indicating whether the communication device 102 or 103 that transmits the Element supports Semi-Async Mode for Multi-Link communication. For example, if this field includes 0, the transmitting device of the Element does not support Semi-Async Mode, and if it includes 1, it supports Semi-Async Mode.

[0071] When the operation information is indicated by the Multi-Link Capability Element, this field may indicate whether or not to execute the Semi-Async Mode of the Multi-Link communication. For example, when the communication device 102 transmits an Association Response, this field indicates whether or not to execute the Semi-Async Mode in the communication of the Link established by the exchange of this association. For example, when this field contains 0, it indicates that the Multi-Link communication in the Semi-Async Mode is not executed. Also, for example, when this field contains 1, it indicates that the Multi-Link communication in the Semi-Async Mode is executed.

[0072] Alternatively, when request information is indicated by a Multi-Link Capability Element, this field may indicate whether or not to request execution of the Semi-Async Mode of Multi-Link communication. For example, when the communication device 103, which is an STA, transmits an Association Request, this field indicates whether or not the communication device 103 requests execution of the Semi-Async Mode in the Multi-Link communication. For example, when this field contains 0, it indicates that execution of the Multi-Link communication in the Semi-Async Mode is not requested. Also, for example, when this field contains 1, it indicates that execution of the Multi-Link communication in the Semi-Async Mode is requested.

[0073] Note that, when the communication devices 102 and 103 perform multi-link communication, if it is preset which of the Sync Mode, the Async Mode, and the Semi-Async Mode to use, these fields may be omitted. Specifically, Sync Mode Support 522, Async Mode Support 523, and Semi-Async Mode Support 528 may be omitted.

[0074] The Total Max Link Number 524 is a field containing capability information indicating the maximum number of links supported by the communication device 102 or 103 transmitting the Element in Multi-Link communication. The maximum number of links is the maximum number of links that the transmitting device of the Element can establish with one other device. For example, if the value of this field is 3, it is indicated that the transmitting device of the Element can establish up to three links with one other device. In this case, the transmitting device of the Element may maintain multiple links with another other device in parallel with maintaining three links with one other device. Alternatively, the maximum number of links may indicate the maximum number of links that the transmitting device of the Element can establish in Multi-Link communication, regardless of the other device. In this case, for example, if the value of this field is 3 and the transmitting device of the Element has established three links with the other device, the transmitting device cannot establish any more links regardless of the other device. The communication device 102, which is an AP, and the communication device 103, which is an STA, each contain information indicating the maximum number of links that their own device can simultaneously maintain in Multi-Link communication in this field.

[0075] When the operation information is indicated by the Multi-Link Capability Element, this field may include the number of links actually established in the Multi-Link communication. For example, when the communication device 102, which is an AP, transmits an Association Response including this Element, this field indicates the number of links established by the exchange of this association. Alternatively, the maximum number of links that can be established in the Multi-Link communication with the communication device 103 may be included. In this case, Total Max Link Number 524 includes a value equal to or less than the smaller value of the maximum number of links that the own device can establish in the Multi-Link communication and the maximum number of links that the other device can establish.

[0076] Alternatively, when request information is indicated by a Multi-Link Capability Element, this field may include the number of links requested to be established in multi-link communication. For example, when communication device 103, which is an STA, transmits an Association Request including this element, this field indicates the number of links that communication device 103 requests communication device 102 to establish. Alternatively, it may include the maximum number of links that can be established in multi-link communication with communication device 102. Note that when operation information or request information is indicated by a Multi-Link Capability Element, this field may be omitted.

[0077] Band Combination Info 525 is a field including capability information indicating the frequency bands supported by the communication device 102 or 103 transmitting the Element during Multi-Link communication. Table 1 shows an example of information indicated by each bit of this field. In Table 1, each bit indicates which frequency band or combination of frequency bands is supported. In this embodiment, if the corresponding bit contains 0, it indicates that the Multi-Link communication in the content indicated by that bit is not supported, and if the corresponding bit contains 1, it indicates that the Multi-Link communication in the content indicated by that bit is supported. For example, if bit 0 in Band Combination Info 525 transmitted by the communication device 102 contains 1, it indicates that the communication device 102 supports Multi-Link communication on different channels in the 2.4 GHz band. Also, for example, if the value of Band Combination Info 525 is 0000111000, it indicates that the communication device 102 supports Multi-Link communication using multiple Links with different frequency bands. In this case, it is indicated that the communication device 102 does not support Multi-Link communication using multiple links with the same frequency band. In addition, by setting all bits of Band Combination Info 525 to 0, it may be indicated that the transmitting device of the Multi-Link Capability Element does not support Multi-Link communication. Alternatively, it may be indicated that the transmitting device of the Element is currently in a state in which Multi-Link communication cannot be performed. Note that the communication devices 102 and 103 may support different frequency bands in communication using only one Link and in Multi-Link communication. For example, the communication devices 102 and 103 may support all of 2.4 GHz, 5 GHz, and 6 GHz in communication using only one Link, but may support only 5 GHz and 6 GHz in Multi-Link communication. Note that the correspondence between each bit of Band Combination Info 525 and its contents is not limited to that shown in Table 1.Also, by increasing the number of bits of Band Combination Info 525, it may be possible to indicate more combinations of frequency bands or whether or not multiple links can be established in different frequency bands.

[0078] [Table 1]

[0079] When the operation information is indicated by the Multi-Link Capability Element, this field may indicate the frequency band actually used in the Multi-Link communication. For example, when the communication device 102, which is an AP, transmits an Association Response including this Element, this field includes information indicating the frequency band of the Link established by the exchange of this association. For example, when the communication devices 102 and 103 establish a 2.4 GHz Link and a 5 GHz Link, the value of Band Combination Info 525 is 00001000.

[0080] Alternatively, when request information is indicated by a Multi-Link Capability Element, this field may indicate a frequency band requested for use in Multi-Link communication. For example, when the communication device 103, which is an STA, transmits an Association Request including this Element, this field indicates a frequency band for which the communication device 103 requests the communication device 102 to execute Multi-Link communication. Note that even when operation information or request information is indicated by this Element, this field may include capability information indicating a frequency band supported by the transmitting device of the Element in Multi-Link communication.

[0081] Per Band Info Number 526 is a field including information indicating the number of Per Band Info included in Per Band Info 512 described later. Per Band Info 512 includes a set of Per Band Info 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 as the number of frequency bands indicated in Band Combination Info 525 is included. Note that this does not apply when information on a plurality of frequency bands is indicated by a common Per Band Info in Per Band Info 512 described later. Also, when Per Band Info 512 described later is omitted, this field is also omitted.

[0082] Per Link Info Number 527 is a field including information indicating the number of Per Link Info included in Per Link Info 513 described later. Per Link Info 513 includes a set of Per Link Info for each Link supported in Multi-Link communication by the communication device 102 or 103 transmitting the Multi-Link Capability Element. When Per Link Info 513 described later is omitted, this field is also omitted.

[0083] Device Type 529 is a field including capability information indicating what type of device the communication device 102 or 103 transmitting the Element is in Multi-link communication. Specifically, information indicating which of the following four types of devices the transmitting device of the Element is is included. A first type of device is a device that can simultaneously transmit data via a certain Link and receive data via another Link in Multi-link communication. A second type of device is a device that can simultaneously transmit data via a certain Link and only transmit data via another Link when transmitting data via a certain Link. A third type of device is a device that can simultaneously receive data via a certain Link and only receive data via another Link when receiving data via a certain Link. A fourth type of device is a device that can simultaneously maintain multiple Links, but cannot simultaneously communicate data via another Link when communicating data via a certain Link.

[0084] When the operation information is indicated by the Multi-Link Capability Element, the Device Type 529 may indicate which type of device both devices will operate as in the Multi-Link communication. For example, when the communication device 102 transmits an Association Response including this element, this field indicates which type of device the device will operate as in the communication of the link established by the exchange of this association. For example, when information indicating the second type is transmitted as the operation information, the communication device 102 operates as a device of the second type in the communication of the link established by the exchange of this association, even if it is a device that can operate as a device of the first type.

[0085] Alternatively, when request information is indicated by the Multi-Link Capability Element, Device Type 529 may indicate what type of device the communication device 103 requests to operate as in Multi-Link communication. For example, when the communication device 103, which is an STA, transmits an Association Request including this element, this field indicates what type of device the communication device 103 wishes to operate as in Multi-Link communication. For example, when information indicating the second type is included in this field, it indicates that the communication device 103 requests to operate as the second type of device in Multi-Link communication with the communication device 102.

[0086] Per Band Info 512 is a field including Band ID 531, Supported Bandwidth 532, Supported CH 533, and Async Mode CH Distance 534. In addition to these fields, Per Band Info 512 further includes Max Link Number 535 and Supported Nss 536. A set of Per Band Info 512 is included in a Multi-Link Capability Element for each frequency indicated by Band ID 531, which will be described later.

[0087] 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 Band ID 531 and the contents indicated by the value. For example, when Band ID 531 includes a value of 0, Per Band Info 512 including this Band ID 531 is information indicating information common to the Links of Multi-Link communication in the 2.4 GHz band. Note that the correspondence between the value included in Band ID 531 and the contents indicated is not limited to this. Also, the number of bits of Band ID 531 may be increased to indicate more frequency bands.

[0088] [Table 2]

[0089] Supported Bandwidth 532 is a field including capability information indicating a bandwidth supported by the communication device 102 or 103 that transmitted the Element in the frequency band indicated by Band ID 531. The bandwidth indicated here is information indicating a bandwidth supported per Link when the transmitting device of the Element performs Multi-Link communication in the frequency band indicated by Band ID 531. Table 3 shows an example of a correspondence relationship between the value included in Supported Bandwidth 532 and the contents indicated by the value. For example, when Supported Bandwidth 532 includes a value of 0, it is indicated that the bandwidth supported by the transmitting device of the Element in the frequency band indicated by Band ID 531 is 20 MHz. When the value of Supported Bandwidth 532 is 1 or more, the transmitting device of the Element can support any bandwidth equal to or less than the value when establishing a Link of Multi-Link communication. For example, when the value of Supported Bandwidth 532 is 2, the transmitting device supports any of 20 MHz, 40 MHz, and 80 MHz as the bandwidth of the Link. The communication devices 102 and 103 may support different bandwidths in communication using only one link and in multi-link communication. For example, the communication devices 102 and 103 may support a bandwidth of 80 MHz at 5 GHz in communication using only one link, but may support a bandwidth of 20 MHz in multi-link communication. The relationship between the value included in Supported Bandwidth 532 and the content indicated is not limited to this. Also, the number of bits in Supported Bandwidth 532 may be increased to indicate more frequency bands.

[0090] [Table 3]

[0091] When the operation information is indicated by the Multi-Link Capability Element, this field may indicate the bandwidth actually used in the Multi-Link communication. For example, when the communication device 102, which is an AP, transmits an Association Response including this Element, this field includes information indicating the bandwidth of the Link established by the exchange of this association. For example, when the communication devices 102 and 103 establish a Link with a bandwidth of 40 MHz at 2.4 GHz, the value of Supported Bandwidth 532 is 1.

[0092] Alternatively, when request information is indicated by a Multi-Link Capability Element, this field may indicate the bandwidth requested for use in Multi-Link communication. When the communication device 103, which is an STA, transmits an Association Request including this Element, this field indicates the bandwidth that the communication device 103 requests from the communication device 102. Note that even when the operation information or request information is indicated by this Element, this field may include capability information indicating the bandwidth that the transmitting device of the Element supports in Multi-Link communication.

[0093] Supported CH533 is a field including capability information indicating a channel supported by the communication device 102 or 103 that transmitted the Element in the frequency band indicated by Band ID531. The channel indicated here is information indicating a channel that the transmission device of the Element supports in the frequency band indicated by Band ID531 for Multi-Link communication. Table 4 shows an example of the correspondence between each bit of Supported CH533 and the channel indicated by the bit. For example, when a bit includes a value of 0, it indicates that the transmission device of the Element does not support the channel indicated by the bit, and when a bit includes a value of 1, it indicates that the transmission device supports the channel indicated by the bit. For example, when Supported CH533 includes a value of 0000010010100, it indicates that the transmission device of this field supports Multi-Link communication in 3ch, 5ch, and 8ch. Note that the communication devices 102 and 103 may support different channels in communication with only one Link and in Multi-Link communication. For example, the communication devices 102 and 103 may support all of 1-13ch in communication using only one link, but may support only some channels such as 1ch and 5ch in multi-link communication. The correspondence between each bit of Supported CH533 and its contents is not limited to that shown in Table 4. In addition, by increasing the number of bits of Supported CH533, more channels may be indicated. For example, in Table 4, only channels at 2.4GHz are shown as an example, but by increasing the number of bits, each channel at 5GHz and 6GHz may be indicated from 13th bit onwards. Alternatively, if information indicating 5GHz is included in Band ID531, each channel at 5GHz may be indicated in ascending order starting from 0 bit. Similarly, if Band ID531 includes 6GHz, each channel at 6GHz may be indicated in descending order starting from 0 bit.

[0094] [Table 4]

[0095] In addition, when the operation information is indicated by the Multi-Link Capability Element, this field may indicate the channel actually used in the Multi-Link communication. For example, when the communication device 102, which is an AP, transmits an Association Response including this Element, this field includes information indicating the channel of the Link established by the exchange of this association. For example, when the communication devices 102 and 103 establish Links of 1ch and 4ch at 2.4GHz, the value of Supported CH533 is 0000000001001.

[0096] Alternatively, when request information is indicated by a Multi-Link Capability Element, this field may indicate a channel requested to be used in Multi-Link communication. For example, when the communication device 103, which is 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. Note that even when the operation information or request information is indicated by this Element, this field may include capability information indicating a channel supported by the transmitting device of the Element in Multi-Link communication.

[0097] Async Mode CH Distance 534 is a field including capability information indicating the channel spacing required in Async Mode by a transmitting device that transmitted the Element in the frequency band indicated by Band ID 531. In Async Mode, communication of each Link is performed asynchronously, so if the channels used by each Link are close to each other, there is a risk of communication interference. The distance between the channels between Links required to properly decode the signal of each Link varies depending on the communication device, so this field is used to notify capability information. For example, if Async Mode CH Distance 534 includes a value of 4, it is indicated that the transmitting device of the Element requires a channel spacing of at least 4ch or more in Async Mode. Note that, if the above-mentioned Async Mode Support 523 includes information indicating that Async Mode is not supported, this field may include a value of 0, or this field may be omitted. In this embodiment, the channel spacing required in Async Mode is indicated for each frequency band indicated by Band ID 531, but this is not limited to this, and the information may be common to each frequency band. Specifically, this field may be included in Common Info 511.

[0098] When the operation information is indicated by the Multi-Link Capability Element, this field may include information indicating the interval of the channel actually used in the Async Mode of the Multi-Link communication. For example, when the communication device 102, which is an AP, transmits an Association Response including this Element, this field includes information indicating the channel interval of the multiple Links established by the exchange of this association.

[0099] Alternatively, when request information is indicated by a Multi-Link Capability Element, this field may include information indicating the interval of the channel requested to be used in the Async Mode of the Multi-Link communication. Information indicating the minimum channel interval supported in the Async Mode of the Multi-Link communication with the other device may be included. When operation information is indicated by the Element, this field includes a value equal to or greater than the larger channel interval between 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. Also, when the Async Mode Support 523 includes information indicating that the Async Mode is not executed, or when the Async Mode Support 523 is omitted, this field may include a value of 0. Alternatively, this field may be omitted. Alternatively, when the communication device 103, which is an STA, transmits an Association Request including this Element, this field indicates the channel interval requested by the communication device 103 in the Async Mode with the communication device 102. Note that, when the communication device 103 does not request execution of the Async Mode, this field may include a value of 0 or may be omitted. When the operation information or request information is indicated by the Multi-Link Capability Element, this field may be omitted.

[0100] Max Link Number 535 is a field including capability information indicating the maximum number of links supported by the transmitting device that transmitted the Element when performing Multi-Link communication in the frequency band indicated by Band ID 531. If the above-mentioned Band Combination Info 525 does not include information indicating that Multi-Link communication between Links in the same frequency band is supported, this field may include a value of 0. Alternatively, this field may be omitted. In addition, in this embodiment, the maximum number of links can be indicated for each frequency band, but this is not limited to the above, and the maximum number of links may be indicated as information common to all frequency bands. Specifically, this field may be included in Common Info 511.

[0101] When operation information is indicated by a Multi-Link Capability Element, this field may indicate the total number of links actually used in the frequency band indicated by Band ID 531 in the Multi-Link communication. For example, when the communication device 102, which is an AP, transmits an Association Response including this Element, this field includes information indicating the number of links, one or more, established by the exchange of this association. For example, when the communication devices 102 and 103 establish two links at 2.4 GHz, this field includes a value of 2.

[0102] Alternatively, when request information is indicated by a Multi-Link Capability Element, this field may indicate the total number of links requested to be used in multi-link communication in the frequency band indicated by Band ID 531. For example, when communication device 103, which is an STA, transmits an Association Request including this Element, this field indicates the number of links that communication device 103 requests communication device 102 to establish. Note that even when operation information or request information is indicated by this Element, this field may include capability information indicating the maximum number of links in multi-link communication by the transmitting device of the Element.

[0103] Supported Nss 536 is a field including capability information indicating the maximum number of (spatial) streams supported by the transmitting device that transmitted the Element when performing Multi-Link communication in the frequency band indicated by Band ID 531. Note that Nss is an abbreviation for Number Of Special Stream. The number of streams indicated in this field is the number of streams in MIMO communication. Note that, if MIMO communication is not supported in Multi-Link communication in the frequency band indicated by Band ID 531, this field includes a value of 0 or 1, or this field is omitted. In addition, in this embodiment, the maximum number of streams can be indicated for each frequency band, but this is not limited to this, and the maximum number of streams may be indicated as information common to all frequency bands. Specifically, this field may be included in Common Info 511.

[0104] In addition, when the operation information is indicated by the Multi-Link Capability Element, this field may indicate the number of streams actually used in the frequency band indicated by the Band ID 531 in the Multi-Link communication. For example, when the communication device 102, which is an AP, transmits an Association Response including this Element, this field includes information indicating the number of streams of the MIMO communication actually performed by the exchange of this association. For example, when the communication devices 102 and 103 perform MIMO communication with three streams in a Link for performing Multi-Link communication at 2.4 GHz, this field includes a value of 3. In addition, when MIMO communication is not performed, this field may include a value of 0 or 1, or this field may be omitted.

[0105] Alternatively, when request information is indicated by the Multi-Link Capability Element, this field may indicate the number of streams requested for use in the frequency band indicated by Band ID 531 in Multi-Link communication. When the communication device 103, which is 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 Multi-Link communication. Note that, when the communication device 103 does not request MIMO communication, this field may include a value of 0 or 1, or this field may be omitted. Also, even when the operation information or request information is indicated by the Element, this field may include capability information indicating the maximum number of streams supported by the transmission device of the Element in MIMO communication in Multi-Link communication.

[0106] Per Link Info513 is a field including each of the fields Link ID541, Band ID542, Bandwidth543, CH544, and Nss545. When capability information is indicated by a Multi-Link Capability Element, Per Link Info513 indicates information on a channel on which the transmitting device of the Element supports Multi-Link communication. In this case, the set of Per Link Info513 includes the number of channels (Links) on which the transmitting device of the Element supports Multi-Link communication. Alternatively, when capability information is indicated by the Element and a Link for Multi-Link communication has already been established, Per Link Info513 indicates information on the Links already established. In this case, the set of Per Link Info513 may include the number of Links already established. In this case, the Link about which the communication device 102 indicates information by Per Link Info513 is established with at least one of the communication device 103 and another communication device. In this case, the link about which the communication device 103 indicates information by the Per Link Info 513 is established with at least one of the communication device 103 and another communication device. Alternatively, when the element indicates capability information, the Per Link Info 513 may not be included. When the operation information is indicated by the Multi-Link Capability Element, the communication device 102, which is the AP, transmits an Association Response including the element, but this is not limited to this. In this case, the Per Link Info 513 indicates information about the link established by the exchange of this association. In this case, the number of Per Link Info 513 included is the number of links established by the exchange of this association.Furthermore, when the communication device 103 indicates request information by transmitting an Association Request including the element, Per Link Info 513 indicates information on a link that the communication device 103 requests to establish. In this case, Per Link Info 513 includes information for the number of links that the communication device 103 requests to establish.

[0107] Link ID 541 is a field that includes an identifier for identifying a link.

[0108] The band ID 542 is a field including information indicating a frequency band to which the link indicated by the link ID 541 belongs. This field is indicated in the same manner as the band ID 531.

[0109] Bandwidth 543 is a field including information indicating the bandwidth in the link indicated by Link ID 541. This field is indicated in the same manner as Supported Bandwidth 532. When capability information is indicated by a Multi-Link Capability Element, this field indicates the bandwidth supported in the link indicated by Link ID 541. When the communication device 102, which is an AP, indicates operation information by transmitting an Association Response including this Element, this field indicates the bandwidth used in the link indicated by Link ID 541. When the communication device 103, which is an STA, indicates request information by transmitting an Association Request including this Element, this field indicates the bandwidth requested by the communication device 103 in the link indicated by Link ID 541.

[0110] CH544 is a field including information indicating a frequency channel of the link indicated by the link ID541. This field may include a number indicating the channel as it is. Alternatively, the channel may be indicated as shown in Table 4. When capability information is indicated by the Multi-Link Capability Element, this field indicates a channel supported in the link indicated by the link ID541. When the communication device 102, which is an AP, indicates operation information by transmitting an Association Response including this element, this field indicates a channel used in the link indicated by the link ID541. When the communication device 103, which is an STA, indicates request information by transmitting an Association Request including this element, this field indicates a channel requested by the communication device 103 in the link indicated by the link ID541.

[0111] Moreover, Nss545 is a field including information indicating the number of streams of MIMO communication in the link indicated by Link ID541. When MIMO communication is not performed, this field may include a value of 0 or 1, or this field may be omitted. When capability information is indicated by a Multi-Link Capability Element, this field indicates the maximum number of streams supported in the link indicated by Link ID541. When the communication device 102, which is an AP, indicates operation information by transmitting an Association Response including this Element, this field indicates the number of streams used in the link indicated by Link ID541. When the communication device 103 indicates request information by transmitting 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 ID541.

[0112] By transmitting and receiving a MAC frame including the above-mentioned Multi-Link Capability Element, the communication devices 102 and 103 exchange capability information, operation information, and request information of Multi-Link communication. In the present embodiment, the capability information, operation information, and request information of Multi-Link communication are indicated by the same Multi-Link Capability Element, but this is not limited to the above. The capability information and the operation information or the capability information and the request information may be indicated by different Information Elements. In this case, for example, the capability information may be indicated by an Element including Common Info 511 and Per Band Info 512. Furthermore, the operation information and the request information may be indicated by an Element including Common Info 511 and Per Link Info 513. Furthermore, when capability information is indicated by the Multi-Link Capability Element, the operation information or the request information may be indicated for some fields. Alternatively, when operation information or the request information is indicated by the Multi-Link Capability Element, the capability information may be indicated for some fields.

[0113] 5 includes fields for Primary CH 521, Supported CH 533, and CH 544 as information indicating a frequency channel. However, this is not limiting, and it is sufficient that the Multi-Link Capability Element includes at least one of Primary CH 521, Supported CH 533, and CH 544 as information indicating a frequency channel.

[0114] Furthermore, the names of the fields, the number of fields, the order of the fields, and the like are not limited to those shown in Fig. 5. Any of the fields may be included before or after any of the fields shown in Fig. 5. Furthermore, a field included in Common Info 511 may be included in Per Band Info 512 or Per Link Info 513. The fields included in Per Band Info 512 and Per Link Info 513 may also be included in the other field or in Common Info 511. Furthermore, any of the fields shown in Fig. 5 may be omitted.

[0115] FIG. 6 is a flowchart showing a process executed by the control unit 202 reading and executing a computer program stored in the storage unit 201 when the communication device 103 performs Multi-Link communication.

[0116] This flowchart starts in response to powering on the communication device 103. Alternatively, the communication device 103 may start in response to an instruction to start Multi-Link communication from a user or an application. Alternatively, the communication device 103 may start in response to the amount of data to be transmitted to the communication device 102 reaching or exceeding a predetermined threshold.

[0117] First, the communication device 103 acquires capability information in Multi-Link communication of the other device (S601). Specifically, the communication device 103 acquires the capability information of the communication device 102 by receiving a Beacon including a Multi-Link Capability Element transmitted by the communication device 102. Alternatively, the communication device 103 may perform the process of this step by receiving a Probe Response including a Multi-Link Capability Element transmitted by the communication device 102. In this case, the order of this step and S602 described later is reversed.

[0118] Next, the communication device 103 notifies its own device of its capability information in Multi-Link communication (S602). Specifically, the communication device 103 notifies its own device of its capability information in Multi-Link communication by transmitting a Probe Request including a Multi-Link Capability Element. If the communication device 103 has acquired capability information of the other device before this step, the communication device 103 may determine the capability information to be notified by the own device based on the capability information of the other device. Specifically, the communication device 103 may determine the capability information to be notified in this step so as not to exceed the capability of the communication device 102. For example, consider a case where the communication device 103 supports Multi-Link communication at 2.4 GHz, 5 GHz, and 6 GHz, and the communication device 102 supports only 2.4 GHz and 5 GHz. In this case, the communication device 103 notifies the fact that it supports Multi-Link communication at 2.4 GHz and 5 GHz as capability information in this step. Note that, when the communication apparatus 103 transmits an Association Request including request information indicating a request for Multi-Link communication to the communication apparatus 102 in S603 described later, the processing of this step may be omitted.

[0119] Next, the communication device 103 transmits an Association Request including request information for Multi-Link communication (S603). The request information transmitted in this step indicates information related to Multi-Link communication that is requested to be executed by the communication device 103. Note that in this step, the communication device 103 may transmit an Association Request that does not include request information.

[0120] The communication device 103 determines whether an Association Response has been received from the communication device 102, which is the AP (S604). If the communication device 103 has not received an Association Response, it determines No in this step and performs the process of this step again. If the communication device 103 has not determined Yes in this step even after a predetermined time has elapsed since the communication device 103 sent the Association Request in S603, it notifies the user of an error and ends the process of this flow. On the other hand, if the communication device 103 has received an Association Response, it determines Yes in this step and performs the process of S605.

[0121] The communication device 103 starts Multi-Link communication with the communication device 102 (S605). If the Association Response received in S604 contains operation information for Multi-Link communication, the communication device 103 starts Multi-Link communication based on the operation information. Alternatively, if request information has been transmitted in S603 and an Association Response containing only information indicating permission has been received in S604, the communication device 103 starts Multi-Link communication based on the request information transmitted in S603. After performing the process of S605, the communication device 103 ends the process of this flow.

[0122] FIG. 7 is a flowchart showing a process executed by the control unit 202 reading and executing a computer program stored in the storage unit 201 when the communication device 102 performs Multi-Link communication.

[0123] This flowchart starts in response to power-on of the communication device 102. Alternatively, the communication device 102 may start in response to an instruction to start Multi-Link communication from a user or an application. Alternatively, the communication device 102 may start in response to the amount of data to be transmitted to the communication device 103 reaching or exceeding a predetermined threshold.

[0124] First, the communication device 102 notifies its own device of its capability information in Multi-Link communication (S701). Specifically, the communication device 102 notifies its own device of its capability information in Multi-Link communication by transmitting a Beacon including a Multi-Link Capability Element. Alternatively, the communication device 102 may perform the process of this step by transmitting a Probe Response including a Multi-Link Capability Element in response to receiving a Probe Response from the communication device 103. In this case, the order of this step and S702 described later is reversed.

[0125] Next, the communication device 102 acquires the capability information of the other device in Multi-Link communication (S702). Specifically, the communication device 102 acquires the capability information of the other device in Multi-Link communication by receiving a Probe Request including a Multi-Link Capability Element. Note that if a Probe Request including a Multi-Link Capability Element is not received from the other device, the process of this step may be omitted.

[0126] When the communication device 102 receives a Probe Request from the communication device 103, the communication device 102 returns a Probe Response as a response. In this case, if a Beacon including a Multi-Link Capability Element is transmitted, the Probe Response does not need to include the Element.

[0127] The communication device 102 determines whether an Association Request has been received from the communication device 103 (S703). If the communication device 102 has not received an Association Request, it determines No in this step and performs the process of this step again. If the communication device 102 has not determined Yes in this step even after a predetermined time has elapsed since transmitting a Probe Response in S702, the communication device 102 notifies the user of an error and ends the process of this flow. On the other hand, if the communication device 102 has received an Association Request, it determines Yes in this step and performs the process of S704.

[0128] Next, the communication device 102 transmits an Association Response as a response to the Association Request (S704). If the request information has not been received from the communication device 103 in S703, the communication device 102 transmits the Association Response including operation information in the Multi-Link communication with the communication device 103. In this case, the communication device 102 determines what operation information to include in the Association Response based on the capability information of the communication device 103 in the Multi-Link communication. The operation information that the communication device 102 transmits by including in the Association Response indicates information on the Multi-Link communication actually performed between the communication devices 102 and 103. Note that even if the request information from the communication device 103 is included in the Association Request received in S703, the communication device 102 may transmit the Association Response including the operation information. In this case, the communication device 102 determines what operation information to include in the Association Response based on the request information from the communication device 103 in the received Association Request. Alternatively, if request information has been received from the communication apparatus 103 in S703, the communication apparatus 102 may transmit an Association Response including only information indicating whether or not Multi-Link communication is permitted.

[0129] The communication device 102 starts Multi-Link communication with the communication device 103 (S705). If the Association Response sent in S704 contains operation information for Multi-Link communication, the communication device 102 starts Multi-Link communication based on the operation information. Alternatively, if the communication device 102 has received request information in S703 and has sent an Association Response in S704 containing only information indicating permission, the communication device 102 starts Multi-Link communication based on the request information received in S703. After performing the process of S705, the communication device 102 ends the process of this flow.

[0130] As described above, the communication devices 102 and 103 can perform Multi-Link communication taking into account each other's capabilities by including an Element indicating capability information for Multi-Link communication in the MAC frame.

[0131] At least a part or all of the flowcharts of the communication devices 103 and 102 shown in Fig. 6 and Fig. 7 may be realized by hardware. When the flowcharts are realized by hardware, for example, a specific compiler may be used to generate a dedicated circuit on an FPGA from a computer program for realizing each step, and this may be used. FPGA is an abbreviation for Field Programmable Gate Array. Also, a gate array circuit may be formed in the same manner as an FPGA, and realized as hardware. Also, it may be realized by an ASIC (Application Specific Integrated Circuit).

[0132] The present invention can also be realized by a process in which a program for implementing one or more of the functions of the above-described embodiments is supplied to a system or device via a network or a storage medium, and one or more processors in a computer of the system or device read and execute the program. The present invention can also be realized by a circuit (e.g., ASIC) that implements one or more of the functions. [Explanation of symbols]

[0133] 101 Network 102 Communication equipment (AP) 103 Communication equipment (STA) 104 First Link 105 Second Link

Claims

1. 1. A communication device, comprising: A communication means for communicating a MAC (Media Access Control) frame conforming to the IEEE 802.11 series standard; An establishment means for establishing a plurality of links, each of which has a different frequency channel, with another communication device, A predetermined MAC frame communicated by the communication means includes a field capable of indicating information indicating a minimum frequency interval related to communication using the plurality of links. A communication device comprising:

2. The predetermined MAC frame includes a Multi-Link Element, The Multi-Link Element includes a field capable of indicating information indicating the minimum frequency interval.

2. The communication device according to claim 1 .

3. The Multi-Link Element includes a Common Info field and a Link Info field, The Common Info field includes a field capable of indicating information indicating the minimum frequency interval.

3. The communication device according to claim 2.

4. The Common Info field is a field containing information common to all links, and the Link Info field is a field containing information unique to each link.

4. The communication device according to claim 3.

5. The field capable of indicating information indicating the minimum frequency interval of the predetermined MAC frame communicated by the communication means indicates information indicating a minimum frequency interval related to communication by the communication device using the multiple links.

5. The communication device according to claim 1, wherein the first and second inputs are connected to the first and second inputs.

6. The information indicating the minimum frequency interval is information indicating a frequency interval that should be secured at least between two links in order for the communication device to asynchronously execute communication using each link in communication using the plurality of links.

6. The communication device according to claim 5,

7. When communication using each of the links is executed asynchronously, the communication device performs communication control so that communication using each of the links can be executed asynchronously, and when the communication device performs the communication control so that communication using each of the links can be executed asynchronously, data transmission through a first link among the links and data reception through a second link among the links can be executed at the same timing.

7. The communication device according to claim 6.

8. The predetermined MAC frame is a Probe Request frame including a Multi-Link Element, The communication means transmits a probe request frame including the multi-link element, and receives a probe response frame including the multi-link element transmitted in response from the other communication device.

8. The communication device according to claim 1, wherein the first and second inputs are connected to the first and second inputs.

9. The predetermined MAC frame is an Association frame including a Multi-Link Element, The establishing means establishes the multiple links with the other communication device by communicating an Association frame including a Multi-Link Element with the other communication device using the communication means.

8. The communication device according to claim 1, wherein the first and second inputs are connected to the first and second inputs.

10. The establishing means identifies a frequency channel based on information indicated by the Multi-Link Element included in the Association frame communicated by the communication means, and establishes the multiple links with the other communication device based on the identified frequency channel.

10. The communication device according to claim 9 .

11. The communication device performs wireless communication with the other communication device in accordance with the IEEE 802.11be standard.

11. The communication device according to claim 1,

12. A method for controlling a communication device, comprising: A communication process for communicating a MAC (Media Access Control) frame conforming to the IEEE 802.11 series standard with another communication device; and establishing a plurality of links with other communication devices via different frequency channels, A predetermined MAC frame communicated by the communication step includes a field capable of indicating information indicating a minimum frequency interval related to communication using the plurality of links. A method for controlling a communication device comprising:

13. A program for causing a computer to function as the communication device control method according to claim 12.

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