COMMUNICATION DEVICE, CONTROL METHOD, AND PROGRAM

Abstract

To suppress communication overhead by appropriately storing information on a frequency channel for performing communication in frames transmitted at predetermined intervals.SOLUTION: When a connection has been established with another communication device via a first frequency channel and a second frequency channel, it is controlled to store information for performing communication in the second frequency channel in a Beacon frame transmitted in the first frequency channel, and to not store the information in a FILS Discovery frame and / or an Unsolicited Probe Response frame.SELECTED DRAWING: Figure 7

Description

[Technical field]

[0001] The present invention relates to a communication device that performs wireless communication. [Background technology]

[0002] The IEEE802.11 standard series is known as a communication standard for wireless LANs (Local Area Networks). IEEE stands for Institute of Electrical and Electronics Engineers, and the IEEE802.11 standard series includes standards such as IEEE802.11a / b / g / n / ac / ax.

[0003] In IEEE802.11ax described in Patent Document 1, in addition to high peak throughput, technology for improving communication speed under congested conditions is standardized. In addition to Beacon frames, IEEE802.11ax allows an AP to transmit FILS Discovery frames at shorter intervals than Beacon frames in order to notify STAs of information required for wireless communication. Here, AP stands for Access Point, STA stands for Station, and FILS stands for Fast Initial Link Setup.

[0004] In order to further improve throughput, a task group was established to develop the IEEE802.11be (hereinafter referred to as 11be) standard as the successor to IEEE802.11ax.

[0005] Conventionally, IEEE802.11 APs establish connections with STAs via a single frequency channel to communicate. In 11be, the introduction of Multi-Link communication is being considered, in which one AP establishes connections with STAs via multiple frequency channels to communicate. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] JP 2018-50133 A Summary of the Invention [Problem to be solved by the invention]

[0007] In order to perform Multi-Link communication, which is being considered for introduction in 11be, it is assumed that information for communication on a second frequency channel will be stored in a Beacon frame or a FILS Discovery frame transmitted on a first frequency channel. However, if information on the second frequency channel is stored and transmitted in each of a Beacon frame and a FILS Discovery frame on the first frequency channel, the amount of information in both frames will increase, which may increase communication overhead.

[0008] In view of the above problems, an object of the present invention is to reduce communication overhead by appropriately storing information about a frequency channel for communication in a frame transmitted at a predetermined interval. [Means for solving the problem]

[0009] In order to achieve the above object, a communication device of the present invention comprises: A communication device capable of establishing a connection with another communication device via a first frequency channel and a second frequency channel, a first transmitting means for transmitting a Beacon frame at a predetermined transmission interval on the first frequency channel; a second transmission means for transmitting a FILS Discovery frame and / or an Unsolicited Probe Response frame at a predetermined transmission interval shorter than that of the Beacon frame in the first frequency channel; a control means for controlling, when a connection with the other communication device is established via the first frequency channel and the second frequency channel, to store information for communication on the second frequency channel in the Beacon frame transmitted by the first transmission means on the first frequency channel, and not to store the information in the FILS Discovery frame and / or the Unsolicited Probe Response frame transmitted by the second transmission means on the first frequency channel; has. Effect of the Invention

[0010] According to the present invention, by appropriately storing information about a frequency channel for communication in a frame transmitted at a predetermined interval, it becomes possible to suppress communication overhead. [Brief description of the drawings]

[0011] [Figure 1] 1 is a diagram illustrating an example of the configuration of a network constructed by a communication device 102. [Diagram 2] FIG. 2 is a diagram illustrating an example of the hardware configuration of communication devices 102 and 103. [Diagram 3] FIG. 2 is a diagram illustrating an example of a functional configuration of communication devices 102 and 103. [Figure 4] 11 is a sequence diagram showing an example of a process executed when the communication device 102 communicates with the communication device 103 via a plurality of links. [Diagram 5] 1 is a flow chart illustrating operations performed by communication device 102 when performing multi-link communication or single-link communication. [Figure 6] 11 is a flowchart showing a process executed when a communication device 102 performing single link communication transmits a frame. [Figure 7] 10 is a flowchart showing a process executed when a communication device 102 performing multi-link communication transmits a frame. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] 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 configurations shown in the drawings.

[0013] 1 shows the configuration of a network in which an AP (Access Point) 102 according to the present embodiment participates. The communication device 102 is a communication device that has a role of constructing a network 101. The network 101 is a wireless network.

[0014] Moreover, the STA (Station) 103 is a communication device 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. Furthermore, EHT is an abbreviation for Extremely High Throughput. Furthermore, 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. Furthermore, each communication device can communicate using bandwidths of 20 MHz, 40 MHz, 80 MHz, 160 MHz, and 320 MHz.

[0015] The communication device 102 and the communication device 103 can realize multi-user (MU, Multi User) 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 carrier waves assigned to each STA are orthogonal. Therefore, the AP can communicate with multiple STAs in parallel.

[0016] Moreover, the communication device 102 and the communication device 103 perform multi-link communication by establishing links via a plurality of frequency channels and communicating. An AP performing multi-link communication is also called an AP MLD (Multi-Link Device). Here, the frequency channel is a frequency channel defined in the IEEE802.11 standard series, and refers to a frequency channel capable of performing wireless communication conforming to the IEEE802.11 standard series. In the IEEE802.11 standard series, a plurality of frequency channels are defined in each of the frequency bands of 2.4 GHz, 5 GHz, and 6 GHz. In addition, in the IEEE802.11 standard series, 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 with the communication device 103 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 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 device 102 and the communication device 103 may establish multiple links of different frequency bands in multi-link communication. For example, the communication device 102 and the communication device 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 of the same frequency band and links of different frequency bands may be mixed.For example, communication device 102 and communication device 103 may establish a third link via 36ch in the 5GHz band in addition to a first link 104 via 1ch in the 2.4GHz band and a second link 105 via 5ch in the 2.4GHz band. By establishing multiple connections with communication device 103 using different frequency bands, communication device 102 can communicate with communication device 103 using the other band even when one band is congested, thereby preventing a decrease in throughput in communication with communication device 103.

[0017] In multi-link communication, the multiple links established between the communication device 102 and the communication device 103 need only have different frequency channels. In multi-link communication, the channel spacing between the frequency channels of the multiple links established between the communication device 102 and the communication device 103 needs only to be at least greater than 20 MHz. In this embodiment, the communication device 102 and the communication device 103 establish the first link 104 and the second link 105, but three or more links may be established.

[0018] When performing multi-link communication, the communication device 102 constructs multiple wireless networks corresponding to the respective links. In this case, the communication device 102 has multiple APs internally and operates to construct a wireless network for each of them. The APs that the communication device 102 has internally may be one or more physical APs, or may be multiple virtual APs configured on one physical AP. When multiple links are established on a frequency channel that belongs to a common frequency band, the multiple links may use a common wireless network.

[0019] When performing multi-link communication, the communication device 102 and the communication device 103 divide one piece of data and transmit it to the other device via multiple links. Alternatively, the communication device 102 and the communication device 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, for example, 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 device 102 and the communication device 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, the 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 responses to the above and provide network information. Association Request frames are frames that request a connection, and Association Response frames are responses to the above and indicate 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 device 102 and the communication device 103 transmit and receive management frames that comply with the IEEE802.11 standard series. 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 device 102 and the communication device 103 may be capable of performing MIMO (Multiple-Input And Multiple-Output) communication. In this case, the communication device 102 and the communication device 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 device 102 and the communication device 103 can communicate more data in the same time compared to when not performing MIMO communication. Furthermore, the communication device 102 and the communication device 103 may perform MIMO communication in some links when performing multi-link communication.

[0021] In order to report network information, the communication device 102 may transmit a FILS Discovery frame and / or an Unsolicited Probe Response frame in addition to a Beacon frame. FILS is an abbreviation for Fast Initial Link Setup. A Beacon frame includes information for communicating on a frequency channel for transmitting a Beacon frame, such as a transmission interval of the Beacon frame and information on an operable frequency channel, and information for a STA that establishes a connection with an AP to perform time synchronization. A FILS Discovery frame is an Action frame, and includes information such as a transmission interval of the Beacon frame and an SSID (Service Set Identifier) ​​of an AP that transmits a FILS Discovery frame. A Beacon frame is transmitted at a predetermined transmission interval, and a FILS Discovery frame and / or an Unsolicited Probe Response frame is transmitted at an interval shorter than the transmission interval of the Beacon frame.

[0022] Furthermore, the communication device 102 can include information on a plurality of APs in the RNR (Reduced Neighbor Report) element of the FILS Discovery frame or the Beacon frame. Here, the information on a plurality of APs refers to information for communication on link 1 and information for communication on link 2 when the communication device communicates via link 1 and link 2. Specifically, the RNR element includes information such as the Operating Class and channel information of each AP, and the transmission timing of the Beacon frame. When multi-link communication is being performed, the communication device 102 can include information on the AP of each link performing the multi-link communication in the RNR element of the FILS Discovery frame or the Beacon frame in addition to the above-mentioned information. Here, the information on the AP of each link includes information for communication on a link that transmits the FILS Discovery frame or the Beacon frame, as well as information for communication on a link different from the link. The FILS Discovery frame includes less information than the Beacon frame.

[0023] The communication device 102 can include the same information as a normal probe response frame in the Unsolicited Probe Response frame. Unlike a normal probe response frame, the Unsolicited Probe Response frame is a frame that the communication device 102 autonomously transmits at a predetermined transmission interval. The communication device 102 that supports multi-link communication can include an RNR element including information about the AP of each link that constitutes the multi-link of the communication device 102 in the Unsolicited Probe Response frame. Here, the information about the AP of each link includes information for communicating through a link that transmits the Unsolicited Probe Response frame, as well as information for communicating through a link different from the link.

[0024] The IEEE802.11ax standard specifies that when an AP operates in the 6 GHz band, the AP may transmit FILS Discovery frames and / or Unsolicited Probe Response frames at intervals of 20 TU. Note that TU is an abbreviation for Time Unit, and 1 TU corresponds to 1 ms. In this case, the AP will transmit FILS Discovery frames and / or Unsolicited Probe Response frames at intervals shorter than the 100 TU transmission interval of Beacon frames.

[0025] When the communication device 102 establishes multiple links including the 6 GHz band, it is necessary to transmit a FILS Discovery frame in addition to a Beacon frame. Therefore, when the frequency band in which multilink communication is performed includes the 6 GHz band, if information related to multilink communication is stored and transmitted in both of the above-mentioned frames, the size of both frames may increase, and the communication throughput may decrease. Therefore, the communication device 102 of the present embodiment suppresses a decrease in communication throughput by appropriately setting information to be stored in the frame based on whether multilink communication is being performed.

[0026] In addition, the communication device 102 and the communication device 103 are described as being compatible with the IEEE802.11be standard. However, in addition to or instead of this, they may be compatible with at least one of 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 and successor standards is called the IEEE802.11 standard series. In addition to the IEEE802.11 standard series, they may be compatible with other communication standards such as Bluetooth (registered trademark), NFC, UWB, Zigbee, and MBOA. UWB is an abbreviation for Ultra Wide Band, and MBOA is an abbreviation for Multi Band OFDM Alliance. OFDM is an abbreviation for Orthogonal Frequency Division Multiplexing. NFC is an abbreviation 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.

[0027] 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 performing multi-link communication with other communication devices. 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, etc. The communication device 103 may be any communication device capable of performing multi-link communication with other communication devices. The network in FIG. 1 is a network configured with one AP and one STA, but the number of APs and STAs is not limited to this.

[0028] In this embodiment, the communication device 102 is an AP and the communication device 103 is an STA, but this is not limiting, and both the communication device 102 and the communication device 103 may be stations. In this case, the communication device 102 is an STA, but operates as a device having a role of constructing a wireless network for establishing a link with the communication device 103.

[0029] 2 shows an example of the hardware configuration of the communication devices 102 and 103. 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.

[0030] 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. Note that, 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 as the storage unit 201. Furthermore, the storage unit 201 may include multiple memories.

[0031] 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.

[0032] 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.

[0033] The input unit 204 receives various operations from the user. The output unit 205 outputs various types of data 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 from it.

[0034] 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 standard series 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. The communication device 102 may have a plurality of communication units 206. When establishing multiple links in multi-link communication, the communication device 102 having a plurality of communication units 206 establishes at least one link per communication unit 206. Alternatively, the communication device 102 may establish multiple links using one communication unit 206. In this case, the communication unit 206 executes communication via multiple links by switching frequency channels that operate in a time-division manner. If the communication device 102 supports the NFC standard, Bluetooth standard, or the like in addition to the IEEE802.11be standard, the communication device 102 may control wireless communication conforming to these communication standards. Furthermore, when the communication device 102 can perform wireless communication conforming to a plurality of communication standards, it may be configured to have a communication unit and an antenna corresponding to each communication standard separately. 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 together with the communication unit 206 as a single module.

[0035] 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.

[0036] 3 shows an example of a functional configuration of the communication device 102. The communication device 102 includes a multilink control unit 301, a FILS Discovery frame generation unit 302, and an Unsolicited Probe Response frame generation unit 303. The communication device 102 further includes a frame transmission interval control unit 304, a Beacon frame generation unit 305, and a frame transmission / reception unit 306.

[0037] The multi-link control unit 301 controls whether the communication device 102 performs multi-link communication or single-link communication. Single-link communication is communication performed by the communication device 102 by establishing a connection in a single link. Whether the communication device 102 performs multi-link communication may be set by the user, or may be determined by the communication device 102 depending on the channel usage status.

[0038] The FILS Discovery frame generation unit 302 generates a FILS Discovery frame in accordance with the multi-link communication in the communication device 102 and the frequency band used by the communication device 102 .

[0039] The Unsolicited Probe Response frame generating unit 303 generates an Unsolicited Probe Response frame in accordance with the multi-link communication in the communication device 102 and the frequency band used by the communication device 102 .

[0040] The frame transmission interval control unit 304 controls the transmission intervals of Beacon frames, FILS Discovery frames, and Unsolicited Probe Response frames in the communication device 102. The transmission interval of Beacon frames is 100 TU, and FILS Discovery frames and Unsolicited Probe Response frames are transmitted at intervals shorter than 100 TU.

[0041] The Beacon frame generating unit 305 generates a Beacon frame. The Beacon frame includes an Unsolicited Probe Responses Active subfield, which is information indicating whether to transmit an Unsolicited Probe Response frame. The Unsolicited Probe Responses Active subfield is included in a Neighbor Report element or an RNR (Reduced Neighbor Report) element. The Beacon frame may also include an RNR element that includes AP information of each link that constitutes the multilink communication of the communication device 102.

[0042] The frame transmission / reception unit 306 controls the transmission and reception of management frames, such as Beacon frames, FILS Discovery frames, and Unsolicited Probe Response frames, control frames, and data frames.

[0043] 4 shows a sequence diagram of processing executed when communication device 102 communicates with communication device 103 via multiple links. The processing of this sequence is started in response to power-on of communication device 102. Alternatively, it may be started in response to a user's instruction to communication device 102 to execute multi-link communication. Communication device 102 operates AP1 and AP2, and executes multi-link communication with communication device 103. Note that AP1 and AP2 operate in the 6 GHz band, and each uses a different frequency channel.

[0044] The communication device 102 transmits a Beacon frame using AP2 (S401). The Beacon frame transmitted in S401 includes an RNR element that stores information for communication using AP1 in addition to information for communication using AP2. Next, the communication device 102 transmits a FILS Discovery frame using AP2 that includes information for communication using AP2 but does not include information for communication using AP1 (S402). In other words, the FILS Discovery frame transmitted here does not include an RNR element. The communication device 102 transmits the FILS Discovery frame at intervals of 20 TU, but the transmission interval does not have to be 20 TU. Note that a bit indicating that the communication device 102 is performing multi-link communication may be added to the FILS Discovery frame to notify that the Beacon frame stores information on another link, that is, information on AP1. When 100TU has elapsed since the previous transmission of a Beacon frame, the communication device 102 stores AP1 information, which is information for communicating via another link, in the RNR element in AP2, and transmits a Beacon frame again (S403). Note that, although this sequence has been described with respect to a case in which the communication device 102 uses AP2, the same process may be performed using AP1.

[0045] In this embodiment, an example has been shown in which information for performing communication via another link is stored in the RNR element, but the information may be stored anywhere within the FILS Discovery frame or Beacon frame.

[0046] In this way, when the communication device 102 executes multi-link communication, in addition to the information for communicating in the own link stored in the Beacon frame, information for communicating in other links is further stored in the RNR element of the Beacon frame. The Beacon frame transmitted here contains information on the multiple links used for multi-link communication, so the communication overhead is large. On the other hand, the FILS Discovery frame does not contain an RNR element storing information for communicating in other links, so the communication overhead is small. In addition, in this embodiment, the communication device 102 transmits a FILS Discovery frame, but instead of at least one FILS Discovery frame, an Unsolicited Probe Response frame may be transmitted.

[0047] FIG. 5 is a flowchart showing a flow of processing performed by control unit 202 executing a program stored in storage unit 201 of communication device 102 when communication device 102 executes multi-link communication or single-link communication.

[0048] This flowchart starts in response to power-on of the communication device 102. Alternatively, the flowchart may start in response to a command from the user to the communication device 102 to start communication.

[0049] First, the communication device 102 determines the operation mode of the device itself to be multilink communication or single link communication (S501). Whether the communication device 102 performs multilink communication or single link communication is determined by the user. Alternatively, the communication device 102 may autonomously determine whether to perform multilink communication or single link communication based on the state of the frequency channel or frequency band, the size of data to be communicated, etc. Alternatively, the AP may determine whether to perform multilink communication or single link communication depending on a request from the STA or the communication status of the STA.

[0050] Next, the communication device 102 judges whether it has received an instruction to stop the AP (S502). Specifically, the communication device 102 judges whether it has received an instruction from a user to stop the operation as an AP. If the instruction to stop is received in S502, the communication device 102 stops the operation as an AP and ends the process of this flowchart. If the instruction to stop is not received in S502, the communication device 102 judges whether the device itself is operating multilink communication (S503). Whether multilink communication is operating is determined by judgment. If it is determined in S503 that the communication device 102 is performing multilink communication, the communication device 102 judges Yes in this step, and performs a frame transmission process in the case where multilink communication is performed in S504. If it is determined in S503 that the communication device 102 is not performing multilink communication, that is, if it is determined that single link communication is performed, the communication device 102 performs a frame transmission process in the case where single link communication is performed (S505). The detailed flow of S504 and S505 will be described later with reference to FIG. 6 and FIG. 7.

[0051] After performing the process of S504 or S505, the communication device 102 determines whether a change regarding the multilink communication has been instructed (S506). Specifically, the communication device 102 determines whether a change instruction regarding whether or not to execute the multilink communication has been received from the user. Alternatively, in addition to this, or instead, the communication device 102 determines whether a change instruction regarding the frequency channel, frequency band, mode, number of links, etc. regarding the multilink communication has been received from the user. Note that, instead of receiving these change instructions from the user, the communication device 102 may autonomously change based on the state of the ongoing communication, the state of the frequency channel, etc. If the communication device 102 has received the change instruction or has determined to autonomously change, it performs the process of S501 again. On the other hand, if the communication device 102 has not received the change instruction or has determined not to autonomously change, it performs the process of S502. The process of S502 is not limited to this timing, and may be performed at any timing in this flowchart.

[0052] FIG. 6 is a flowchart showing a flow of processing performed by the control unit 202 executing a program stored in the storage unit 201 of the communication device 102 when the communication device 102 performing single link communication transmits a frame.

[0053] The process of this flowchart starts in response to the communication device 102 starting the process of S505 in FIG.

[0054] First, the communication device 102 determines whether the transmission interval of the FILS Discovery frame has elapsed since the previous transmission of the Beacon frame or the FILS Discovery frame (S601). If it is determined in S601 that the transmission interval has not elapsed, the communication device 102 determines whether the transmission interval of the Beacon frame has elapsed since the previous transmission of the Beacon frame (S602). The transmission interval of the Beacon frame of the communication device 102 is preset as 100 TU in the communication device 102. Alternatively, an arbitrary transmission interval may be set by the user. If it is determined in S602 that the Beacon transmission interval has elapsed, the communication device 102 transmits a Beacon frame (S605). If it is determined in S602 that the communication device 102 proceeds to the processing of S506 in FIG. 5 that the communication device 102 has not elapsed, the communication device 102 performs the processing of S601 again.

[0055] If it is determined in S601 that the transmission interval has elapsed, the communication device 102 determines whether the transmission interval of the Beacon frame has elapsed (S603). If it is determined in S603 that the Beacon transmission interval has not elapsed, the communication device 102 transmits a FILS Discovery frame (S604). After performing the process of S604, the communication device 102 performs the determination of S601 again. If it is determined in S603 that the Beacon transmission interval has elapsed, the communication device 102 transmits a Beacon frame in S605 and ends the process of this flowchart.

[0056] Although a FILS Discovery frame is transmitted in FIG. 6, the present invention is not limited to this and an Unsolicited Probe Response frame may be transmitted.

[0057] When the communication device 102 performs single-link communication as in this embodiment, the RNR element storing information for performing communication via other links is not included in either the FILS Discovery frame or the Beacon frame.

[0058] FIG. 7 is a flowchart showing a flow of processing performed by control unit 202 executing a program stored in storage unit 201 of communication device 102 when communication device 102 performing multi-link communication transmits a frame.

[0059] The process of this flowchart starts in response to the communication device 102 starting the process of S504 in FIG.

[0060] First, the communication device 102 stores in a Beacon frame a Multi link element indicating operation information of multi-link communication and an RNR element storing AP information of a link other than the link transmitting a Beacon frame (S701). Information for performing communication on a link transmitting a Beacon frame is stored in an element such as EHT Capability of the Beacon frame, but may be stored anywhere in the Beacon frame. Next, the communication device 102 determines whether or not the load of communication between the communication device 102 and the communication device 103 is high when the RNR element including information for performing communication on another link is stored in the FILS Discovery frame (S702). The load of communication between the communication device 102 and the communication device 103 when the RNR element is stored in the FILS Discovery frame is determined by determining whether the FILS Discovery frame size is larger than a predetermined threshold. Alternatively, in S702, the communication device 102 determines whether the number of links through which the communication device 102 and the communication device 103 have established a connection is larger than a predetermined threshold. Alternatively, in S702, the communication device 102 determines whether the transmission interval of the FILS Discovery frame is smaller than a predetermined threshold. If it is determined in S702 that the load of the communication between the communication device 102 and the communication device 103 is high, the communication device 102 determines whether the transmission interval of the FILS Discovery frame has elapsed in S704. If it is determined in S702 that the load of the communication between the communication device 102 and the communication device 103 is low, the communication device 102 stores an RNR element in the FILS Discovery frame (S703). Note that which of the FILS Discovery frame size, the number of links, or the transmission interval of the FILS Discovery frame to determine in S702 may be selected by the user or may be preset in the communication device 102. Alternatively, the communication device 102 may perform three determinations, and if at least one of the determination results is Yes, the determination in this step may be Yes.The predetermined threshold for the FILS Discovery frame, the predetermined threshold for the number of links, and the threshold for the transmission interval of the FILS Discovery frame may all be stored in a non-volatile memory in the communication device 102, or may be set by the user.

[0061] In addition, a bit indicating that the communication device 102 is performing multi-link communication may be added to the FILS Discovery frame, so that it is possible to notify that the Beacon frame contains information for performing communication via other links.

[0062] The processes in S704 to S708 are the same as those in S601 to S605 in Fig. 6. Once the Beacon frame is transmitted in S708, the process proceeds to S506 in Fig. 5.

[0063] Although a FILS Discovery frame is transmitted in FIG. 7, the present invention is not limited to this and an Unsolicited Probe Response frame may be transmitted.

[0064] Also, the determination in S702 and the process in S703 may be skipped. In this case, the communication device 102 does not store information for communication via other links in the frame as an RNR element based on the fact that multilink communication is being performed, without considering the load when transmitting a FILS Discovery frame.

[0065] 5 to 7 may be executed when the communication device 102 operates only in the 6 GHz band, and may not be executed when the communication device 102 operates in the 2.4 GHz band and / or the 5 GHz band. Alternatively, the communication device 102 may execute the processes in FIGS. 5 to 7 based on the fact that at least one AP operates in the 6 GHz band.

[0066] 5 to 7, processes other than the transmission process of the Beacon frame are omitted, but the present invention is not limited to this. The communication device 102 may perform processes such as transmission and reception of data frames, other management frames, and control frames in parallel with or between each step in Fig. 5 to Fig. 7.

[0067] According to this embodiment, the communication device 102 appropriately stores information for communicating on other frequency channels in frames transmitted at a predetermined transmission interval, and controls the transmission of the frames, thereby making it possible to reduce communication overhead.

[0068] At least a part or all of the flowcharts of the communication device 102 shown in Figures 5 to 7 may be realized by hardware. When realizing 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).

[0069] A recording medium on which the program code of the software for realizing the above-mentioned functions is recorded may be supplied to the system or device, and the computer (CPU, MPU) of the system or device may read and execute the program code stored in the recording medium. In this case, the program code itself read from the storage medium will realize the functions of the above-mentioned embodiments, and the storage medium on which the program code is stored will constitute the above-mentioned device.

[0070] Examples of storage media for supplying the program code include flexible disks, hard disks, optical disks, magneto-optical disks, CD-ROMs, CD-Rs, magnetic tapes, non-volatile memory cards, ROMs, and DVDs.

[0071] In addition, the above-mentioned functions may be realized not only by the computer executing the read program code, but also by the OS running on the computer performing all or part of the actual processing based on the instructions of the program code. OS is an abbreviation for Operating System.

[0072] Furthermore, the program code read from the storage medium may be written to a memory provided in a function expansion board inserted into the computer or a function expansion unit connected to the computer, and a CPU provided in the function expansion board or function expansion unit may perform part or all of the actual processing based on instructions in the program code to realize the above-mentioned functions.

[0073] 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]

[0074] 201 Storage section 202 Control section 203 Functional Department 204 Input section 205 Output section 206 Communications Department 207 Antenna

Claims

1. A communication device capable of establishing a connection with another communication device via a first frequency channel and a second frequency channel, a first transmitting means for transmitting a beacon frame at a predetermined transmission interval on the first frequency channel; a second transmitting means for transmitting a FILS Discovery frame and / or an Unsolicited Probe Response frame at a predetermined transmission interval shorter than that of the Beacon frame in the first frequency channel; a control means for controlling, when a connection with the other communication device has been established via the first frequency channel and the second frequency channel, to store information for communication on the second frequency channel in the Beacon frame transmitted by the first transmitting means on the first frequency channel, and not to store the information in the FILS Discovery frame and / or the Unsolicited Probe Response frame transmitted by the second transmitting means on the first frequency channel; A communication device comprising:

2. a determination means for determining a load of communication between the communication device and the other communication device when a connection with the other communication device is established via the first frequency channel and the second frequency channel; 2. The communication device according to claim 1, wherein, when the determination means determines that the communication load is high, the control means performs control to store the information in the Beacon frame transmitted by the first transmission means on the first frequency channel, and not to store the information in the FILS Discovery frame and / or the Unsolicited Probe Response frame transmitted by the second transmission means on the first frequency channel.

3. the determining means determines the communication load based on a size of the FILS Discovery frame when the information is stored in the FILS Discovery frame and / or the Unsolicited Probe Response frame; 3. The communication device according to claim 2, wherein, when the determination means determines that the size of the FILS Discovery frame and / or the Unsolicited Probe Response frame is larger than a predetermined value, the control means performs control to store the information in the Beacon frame transmitted by the first transmission means on the first frequency channel, and not to store the information in the FILS Discovery frame and / or the Unsolicited Probe Response frame transmitted by the second transmission means on the first frequency channel.

4. The determining means determines the communication load based on the number of frequency channels to which the communication device and the other communication device have established a connection; 4. The communication device according to claim 2, wherein, when the determination means determines that the number of frequency channels is greater than a predetermined value, the control means performs control to store the information in the Beacon frame transmitted by the first transmission means on the first frequency channel, and not to store the information in the FILS Discovery frame and / or the Unsolicited Probe Response frame transmitted by the second transmission means on the first frequency channel.

5. the determining means determines a communication load based on a transmission interval of the FILS Discovery frame and / or the Unsolicited Probe Response frame transmitted by the second transmitting means; 5. The communication device according to claim 2, wherein, when the determination means determines that the transmission interval of the FILS Discovery frame and / or the Unsolicited Probe Response frame is smaller than a predetermined value, the control means performs control to store the information in the Beacon frame transmitted by the first transmission means on the first frequency channel, and not to store the information in the FILS Discovery frame and / or the Unsolicited Probe Response frame transmitted by the second transmission means on the first frequency channel.

6. The communication device according to claim 1 , wherein the information is included in a Reduced Neighbor Report (RNR) element of the beacon frame.

7. 7. The communication device according to claim 1, wherein the FILS Discovery frame and / or the Unsolicited Probe Response frame and the Beacon frame include information about a network established by the communication device that transmits the frame.

8. 8. The communication device according to claim 1, wherein the first frequency channel and the second frequency channel are channels in any one of a 2.4 GHz band, a 5 GHz band, and a 6 GHz band.

9. 9. The communication device according to claim 1, wherein the communication device operates as an AP (Access Point) conforming to the IEEE 802.11 standard series.

10. A communication method for a communication device capable of establishing a connection with another communication device via a first frequency channel and a second frequency channel, comprising: a first transmission step of transmitting a beacon frame at a predetermined transmission interval on the first frequency channel; a second transmission step of transmitting a FILS Discovery frame and / or an Unsolicited Probe Response frame at a predetermined transmission interval shorter than that of the Beacon frame in the first frequency channel; a control step of storing information for performing communication on the second frequency channel in the Beacon frame transmitted in the first frequency channel by the first transmitting step when a connection with the other communication device has been established via the first frequency channel and the second frequency channel, and controlling so as not to store the information in the FILS Discovery frame and / or the Unsolicited Probe Response frame transmitted in the second transmitting step by the first frequency channel; A communication method for a communication device, comprising:

11. A program for causing a computer to function as each of the means of the communication device according to any one of claims 1 to 9.

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