Communication device, communication method, and program

Abstract

To suppress useless transmission of a frame to a frequency channel not to be transmitted when a communication device is connected to a plurality of other communication devices and is connected to at least one other communication device via a plurality of frequency channels.SOLUTION: In a state in which a communication device and a first other communication device establish a connection via a first frequency channel and a second frequency channel, and the communication device and a second other communication device establish a connection via a third frequency channel and a fourth frequency channel, when the first frequency channel and the third frequency channel are the same frequency channel, it is determined that the frame is transmitted by multicast communication or broadcast communication on the first frequency channel and the third frequency channel, the frame is transmitted on the determined first frequency channel and third frequency channel, and the frame is not transmitted on the undetermined frequency channel.SELECTED DRAWING: Figure 6

Description

Technical Field

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

Background Art

[0002] As a WLAN communication standard established by IEEE (Institute of Electrical and Electronics Engineers), the IEEE 802.11 standard series is known. Note that WLAN is an abbreviation for Wireless Local Area Network. The IEEE 802.11 series standards include standards such as IEEE 802.11a / b / g / n / ac / ax standards.

[0003] In IEEE 802.11ax described in Patent Document 1, in addition to a high peak throughput of up to 9.6 gigabits per second (Gbps) by OFDMA, an improvement in communication speed under congested conditions is achieved. Note that OFDMA is an abbreviation for Orthogonal Frequency-Division Multiple Access.

[0004] In order to further improve throughput, a Task Group for formulating the IEEE 802.11be standard has been established as a successor standard to IEEE 802.11ax.

[0005] In the IEEE 802.11be standard, a technique is being studied in which one AP (Access Point) establishes and communicates with one STA (Station) through a plurality of different frequency channels via a plurality of links.

Prior Art Documents

Patent Documents

[0006]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0007] In the IEEE802.11be standard, Multi-Link communication is being considered, in which an AP and an STA establish a connection via a plurality of channels and communicate in parallel.

[0008] When an AP and a plurality of STAs establish a connection via a plurality of frequency channels, if the AP transmits a frame to the plurality of STAs by multicast communication or broadcast communication, the same frame is transmitted to the same STA. Therefore, frames may be redundantly transmitted to frequency channels that do not need to be transmitted, resulting in unnecessary frame transmission for the AP.

[0009] In view of the above problems, the present invention aims to suppress the unnecessary transmission of frames to frequency channels when a communication device is connected to a plurality of other communication devices and is connected to at least one other communication device via a plurality of frequency channels.

Means for Solving the Problems

[0010] To achieve the above object, the communication device of the present invention includes: establishing means for establishing a connection between the communication device and a first other communication device via one or more links, and establishing a connection between the communication device and a second other communication device via one or more links; determining means for determining, among a plurality of frequency channels used in the links established by the establishing means, the frequency channels necessary for a frame transmitted by multicast communication or broadcast communication to reach the first other communication device and the second other communication device; transmitting means for transmitting the frame on the frequency channels determined by the determining means; having, in a state where the communication device and the first other communication device have established a connection via a first frequency channel and a second frequency channel, and the communication device and the second other communication device have established a connection via a third frequency channel and a fourth frequency channel, when the first frequency channel and the third frequency channel are the same frequency channel, the determining means determines to transmit the frame on the first frequency channel and the third frequency channel, transmitting the frame on the first frequency channel and the third frequency channel determined by the determining means Do it.

Advantages of the Invention

[0012] According to the present invention, when a communication device is connected to a plurality of other communication devices and is connected to at least one other communication device via a plurality of frequency channels, it is possible to suppress the unnecessary transmission of frames to frequency channels that do not need to be transmitted.

Brief Description of the Drawings

[0013]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Modes for Carrying Out the Invention

[0014] (Embodiment 1) Hereinafter, embodiments 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.

[0015] FIG. 1 shows the configuration of the network constructed by the communication device 102 according to this embodiment. The communication device 102 is an access point (AP) having a role of constructing the network 101. Note that the network 101 is a wireless network.

[0016] In addition, the communication devices 103 to 106 are stations (STAs) having a role of participating in the network 101. Each communication device complies with the IEEE802.11be (EHT) standard and can perform wireless communication compliant with 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 also be interpreted as an abbreviation for Extreme High Throughput. Each communication device can communicate in frequency bands of 2.4 GHz, 5 GHz, and 6 GHz. The frequency band used by each communication device is not limited to this, and different frequency bands such as the 60 GHz band may be used. In addition, each communication device can communicate using bandwidths of 20 MHz, 40 MHz, 80 MHz, 160 MHz, and 320 MHz.

[0017] The communication devices 102 to 106 can realize multi-user (MU) communication in which signals of a plurality of users are multiplexed by performing OFDMA communication compliant with the IEEE802.11be standard. OFDMA communication is an abbreviation for Orthogonal Frequency Division Multiple Access. In OFDMA communication, a part (RU, Resource Unit) of the divided frequency band is allocated so as not to overlap each STA, and the carriers allocated to each STA are orthogonal. Therefore, the AP can communicate with a plurality of STAs in parallel. 113 to 116 indicate that the communication device 102 has one or more wireless connection links with each of the communication devices 103 to 108.

[0018] FIG. 2 shows an example of the frequency channel configuration of the network constructed by the communication device 102. The communication devices 102 to 106 establish a Link via a plurality of frequency channels and perform Multi-Link communication. 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 compliant with the IEEE802.11 series standard. In the IEEE802.11 series standard, a plurality of frequency channels are defined in each of the 2.4 GHz band, 5 GHz band, and 6 GHz band. Also, in the IEEE802.11 series standard, the bandwidth of each frequency channel is defined as 20 MHz. Incidentally, by bonding with an adjacent frequency channel, a bandwidth of 40 MHz or more may be used in one frequency channel. The communication device 102 and the communication device 103 are connected by the frequency channel 1ch (201) and the frequency channel 48ch (204). The communication device 102 and the communication device 104 are connected by the frequency channel 1ch (202) and the frequency channel 36ch (203). The communication device 102 and the communication device 105 are connected by the frequency channel 48ch (205) and the frequency channel 100ch (206). The communication device 102 and the communication device 106 are connected by the frequency channel 100ch (207). In this way, the communication device 102 can improve the throughput in communication with the communication devices 103 to 106 by establishing Links via a plurality of frequency channels with the communication devices 103 to 106. Also, the communication device 102 can communicate with the communication devices 103 to 106 in another frequency band even when a predetermined frequency band is congested by establishing a plurality of connections with different frequency bands with the communication devices 103 to 106. Therefore, it is possible to prevent a decrease in throughput in communication with the communication devices 103 to 106.

[0019] In Multi-Link communication, the plurality of Links established by each of communication devices 102 and 103 to 106 only need to have at least different respective frequency channels. In Multi-Link communication, the channel interval of the frequency channels of the plurality of Links established between communication device 102 and each of 103 to 106 only needs to be greater than at least 20 MHz.

[0020] When performing Multi-Link communication, the communication device 102 divides one piece of data and transmits it to the peer device via multiple Links. Alternatively, the communication devices 102 and 103 to 106 may transmit the same data via each of the multiple Links, so that the communication via one Link can be used as a backup communication for the communication via the other Link. Specifically, assume that the communication device 102 transmits the same data to the communication device 104 via the first Link via 1ch and the second Link via 36ch. In this case, even if an error occurs in the communication via the first Link (1ch), since the same data is being transmitted via the second Link (36ch), the communication device 104 can receive the data transmitted from the communication device 102. Alternatively, the communication device 102 may use the Links appropriately according to the type of frame to be communicated or the type of data. For example, the communication device 102 may transmit management frames via the first Link (1ch) and data frames containing data via the second Link (36ch). Note that the management frame specifically refers to a Beacon frame, a Probe Request frame / Response frame, and an Association Request frame / Response frame. In addition to these frames, a Disassociation frame, an Authentication frame, a De-Authentication frame, and an Action frame are also called management frames. A Beacon frame is a frame that notifies network information. A Probe Request frame is a frame that requests network information, and a Probe Response frame is its response and is a frame that provides network information. An Association Request frame is a frame that requests a connection, and an Association Response frame is its response and is a frame that indicates permission or an error for the connection. A Disassociation frame is a frame that disconnects the connection.An Authentication frame is a frame for authenticating a peer device, and a De-Authentication frame is a frame for interrupting the authentication of a peer device and disconnecting the connection. An Action frame is a frame for performing additional functions other than the above. Communication devices 102 to 106 transmit and receive management frames compliant with the IEEE802.11 series standards. Alternatively, when the communication device 102 transmits data related to, for example, a captured image, meta information such as a date, parameters at the time of imaging (aperture value and shutter speed), and location information may be transmitted via the first Link, and pixel information may be transmitted via the second Link.

[0021] In addition, communication devices 102 to 106 may be able to execute MIMO (Multiple-Input And Multiple-Output) communication. In this case, communication devices 102 to 106 have a plurality of antennas, and one of them sends different signals from each antenna using the same frequency channel. The receiving side simultaneously receives all the signals that have arrived from multiple streams using a plurality of antennas, separates the signals of each stream, and decodes them. By executing MIMO communication in this way, communication devices 102 to 106 can communicate more data in the same time compared to the case where MIMO communication is not executed. Also, when communication devices 102 to 104 perform Multi-Link communication, they may execute MIMO communication on some Links.

[0022] Furthermore, although communication devices 102 to 106 are assumed to comply with the IEEE802.11be standard, they may additionally or alternatively comply with at least one of the legacy standards that are older than the IEEE802.11be standard. The legacy standards refer to 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 referred to as the IEEE802.11 series of standards. In addition to the IEEE802.11 series of standards, the communication devices may also comply with other communication standards such as Bluetooth (registered trademark), NFC, UWB, Zigbee, and MBOA. Note that UWB is an abbreviation for Ultra Wide Band, MBOA is an abbreviation for Multi Band OFDM Alliance, OFDM is an abbreviation for Orthogonal Frequency Division Multiplexing, and NFC is an abbreviation for Near Field Communication. UWB includes wireless USB, wireless 1394, and Winet. The communication devices may also comply with the communication standards of wired communications such as wired LAN.

[0023] 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 device that can perform Multi-Link communication with other communication devices. Specific examples of the communication devices 103 to 106 include, but are not limited to, a camera, a tablet, a smartphone, a PC, a mobile phone, and a video camera. The communication devices 103 to 106 may be any devices that can perform wireless Link communication with other communication devices. Although the networks in FIGS. 1 and 2 are composed of one AP and four STAs, the number of APs and STAs is not limited to this.

[0024] FIG. 3 shows the hardware configuration of the communication device 102 in the present embodiment. The communication device 102 includes a storage unit 301, a control unit 302, a functional unit 303, an input unit 304, an output unit 305, a communication unit 306, and an antenna 307.

[0025] The storage unit 301 is composed of one or more memories such as ROM and RAM, and stores computer programs for performing various operations described later, and various information such as communication parameters for wireless communication. ROM is an abbreviation for Read Only Memory, and RAM is an abbreviation for Random Access Memory. 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 301. Further, the storage unit 301 may include a plurality of memories and the like.

[0026] The control unit 302 is composed of one or more processors such as a CPU or an MPU, for example, and controls the entire communication device 102 by executing the computer program stored in the storage unit 301. In addition, the control unit 302 may control the entire communication device 102 in cooperation with the computer program stored in the storage unit 301 and the OS (Operating System). Further, the control unit 302 generates data and signals (wireless frames) to be transmitted in communication with other communication devices. CPU is an abbreviation for Central Processing Unit, and MPU is an abbreviation for Micro Processing Unit. In addition, the control unit 302 may include a plurality of processors such as a multi-core, and control the entire communication device 102 by the plurality of processors.

[0027] In addition, the control unit 302 controls the functional unit 303 to execute predetermined processes such as wireless communication, imaging, printing, and projection. The functional unit 303 is hardware for the communication device 102 to execute predetermined processes.

[0028] The input unit 304 receives various operations from the user. The output unit 305 performs various outputs to the user via a monitor screen or a speaker. Here, the output by the output unit 305 may be a display on the monitor screen, an audio output by the speaker, a vibration output, etc. Note that both the input unit 304 and the output unit 305 may be realized by one module such as a touch panel. Also, the input unit 304 and the output unit 305 may be integrated with the communication device 102 or may be separate entities.

[0029] The communication unit 306 controls wireless communication compliant with the IEEE802.11be standard. In addition to the IEEE802.11be standard, the communication unit 306 may control wireless communication compliant with other IEEE802.11 standard series or control wired communication such as a wired LAN. The communication unit 306 controls the antenna 307 to transmit and receive signals for wireless communication generated by the control unit 302. Note that when the communication device 102 supports communication standards such as the NFC standard and the Bluetooth standard in addition to the IEEE802.11be standard, it may control wireless communication compliant with these communication standards. Also, when the communication device 102 can execute wireless communication compliant with multiple communication standards, it may have a configuration with separate communication units and antennas 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 306. Note that the antenna 307 may be configured separately from the communication unit 306 or may be configured as one module together with the communication unit 306.

[0030] The antenna 307 is an antenna capable of communication in the 2.4 GHz band, 5 GHz band, and 6 GHz band. In this embodiment, it is assumed that the communication device 102 has one antenna, but it may have different antennas for each frequency band. Also, when the communication device 102 has a plurality of antennas, it may have a communication unit 306 corresponding to each antenna.

[0031] Note that the communication devices 103 to 106 have the same hardware configuration as the communication device 102.

[0032] FIG. 4 shows the functional configuration of the communication device 102 in the present embodiment. The communication device 102 includes a Multi-Link communication capability information generation unit 401, a Multi-Link communication operation information determination unit 402, a Group Addressed Frame transmission frequency channel determination unit 403, a connection processing unit 404, and a data transmission / reception unit 406.

[0033] The capability information generation unit 401 is a block that generates capability information regarding the Multi-Link communication of the communication device 102. The communication device 102 generates capability information for notifying other communication devices of the capabilities of its own Multi-Link communication. Here, the capability information refers to the frequency bands, frequency channels, and bandwidths that the communication device 102 can use. Note that regarding the capability information, the capability information of its own device may be notified to other communication devices, or the capability information of the other device may be received only from other communication devices.

[0034] The operation information determination unit 402 is a block that determines operation information regarding the Multi-Link communication with the other device based on the capability information regarding the Multi-Link communication of its own device and the other device. The operation information regarding the Multi-Link communication refers to the frequency channels, bandwidths, etc. used in the Multi-Link communication between the communication devices 102 and 103 to 106. Regarding the operation information, the determined operation information may or may not be notified to the other device.

[0035] The Group Addressed Frame transmission frequency channel determination unit 403 This is a block that determines the group of frequency channels to which the Group Addressed Frame is to be transmitted. The frequency channels for transmitting the Group Addressed Frame are determined based on the information regarding the connection of the frequency channels obtained from the capability information generation unit 401 or the connection processing unit 404. Here, the Group Addressed Frame refers to a frame that includes an address in which the Group Bit is 1 in the MAC address included in the Destination Address (DA) of the MAC frame. For example, a frame transmitted in broadcast communication such as a Beacon frame is a type of Group Addressed Frame because the Group Bit is 1. Also, for a multicast frame, since the Group Bit is similarly set to 1, it becomes a Group Addressed Frame. The Group Addressed Frame is transmitted in multicast communication / broadcast communication.

[0036] The connection processing unit 404 is a block that performs processing for allowing the communication devices 103 to 106, which are STAs, to participate in the network constructed by the communication device 102. Specifically, for example, the connection processing unit 404 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. Note that the communication device 102 may have a connection processing unit 404 corresponding to each of the plurality of Links for which the device itself establishes a connection, or may use one connection processing unit 404 in a time-division manner.

[0037] The data transmission / reception unit 406 is a block that transmits and receives data frames in Multi-Link communication based on the operation information regarding Multi-Link communication determined by the operation information determination unit 402.

[0038] Note that the communication devices 103 to 106 have the same functional configuration as the communication device 102, but differ in the following points.

[0039] Communication devices 103 to 106 have a request information determination unit (not shown) instead of the operation information determination unit 402. It is a block that determines request information regarding Multi-Link communication with the peer device based on the capability information regarding Multi-Link communication of the own device and the peer device. The request information regarding Multi-Link communication refers to frequency channels, bandwidths, etc. that are required to be used in the Multi-Link communication between communication devices 102 and 103 to 106. Regarding the request information, the determined request information may or may not be notified to the peer device.

[0040] Fig. 5 shows a sequence diagram illustrating an example of the processing executed when communication device 102 and communication device 103 perform Multi-Link communication.

[0041] An example is shown in which communication device 102 and communication device 103 perform communication via channel 1 in the 2.4 GHz band on the first Link and perform communication processing via channel 36 in the 5 GHz band on the second Link.

[0042] The processing of this sequence is started in response to the power-on of each of communication devices 102 and 103. Alternatively, at least one of communication devices 102 and 103 may be started in response to being instructed to start Multi-Link communication by a user or an application. Alternatively, at least one of communication devices 102 and 103 may be started in response to the data volume of the data to be communicated with the peer device reaching a predetermined threshold or more.

[0043] First, communication device 102 notifies the surrounding STAs of the network information by transmitting a Beacon including the network information of the own device on channel 1 (S501). Specifically, the network information is the transmission interval at which communication device 102 transmits the Beacon and the SSID of communication device 102. The SSID is an abbreviation for Service Set Identifier. In addition to this, communication device 102 may notify the capability information regarding the Multi-Link communication of communication device 102 by including the network information in the Beacon.

[0044] When the communication device 103 receives the Beacon of the communication device 102 being transmitted on channel 1, it transmits a Probe Request on channel 1 (S502). The Probe Request includes the SSID of the communication device 103. In addition to this, the communication device 103 notifies the capability information regarding the Multi-Link communication of the communication device 103.

[0045] When the communication device 102 receives the Probe Request, it transmits a Probe Response to the communication device 103 on channel 1 as a response (S503). If the communication device 102 does not include the capability information regarding the Multi-Link communication in the Beacon, it includes the capability information in the Probe Response and transmits it. Alternatively, the communication device 102 may include only a part of the capability information regarding the Multi-Link communication in the Beacon and include the remaining information or all of the information in the Probe Response.

[0046] By performing the processes of S501 to S503, the communication devices 102 and 103 can exchange the capability information regarding their respective Multi-Link communications.

[0047] Next, the communication device 103 transmits an Association Request, which is a connection request, on Channel 1 to the communication device 102. In this case, the communication device 103 may notify the capability information regarding the Multi-Link communication of the communication device 103 by including the capability information regarding the Multi-Link communication in the Association Request. Note that the communication device 103 may determine the capability information to be transmitted in S504 based on the capability information regarding the Multi-Link communication of the communication device 102 acquired in at least one of S501 or S503. For example, even if the communication device 103 can combine Links in the 2.4 GHz band and the 5 GHz band in Multi-Link communication, assume that the communication device 102 only supports a plurality of Links within the 2.4 GHz band. In this case, the communication device 103 may transmit only the capability information regarding the establishment of a plurality of Links in the 2.4 GHz band as the capability information to be transmitted in this step. Also, in the present embodiment, the communication device 103 transmits the capability information regarding its own Multi-Link communication in S502. However, the present invention is not limited to this, and the capability information may not be transmitted in S502 and may be transmitted only in this step. Alternatively, the communication device 103 may transmit, instead of the capability information, the request information required when performing Multi-Link communication by including the capability information regarding the Multi-Link communication in the Association Request. The request information required by the communication device 103 may be indicated by the capability information regarding the Multi-Link or may be indicated by another Element.

[0048] When the communication device 102 receives an Association Request, it transmits an Association Response as a response to the communication device 103 on 1ch (S505). The Association Response transmitted here includes the operation information for performing Multi-Link communication with the communication device 103 determined by the communication device 102. Also, when the communication device 103, which is a STA, transmits an Association Request including the operation information requested in S504, the communication device 102 may transmit an Association Response including only the approval or disapproval of the request.

[0049] 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 1ch and start data communication (S506). Also, in this case, if the operation information of the Link via 36ch is included in the operation information transmitted by the communication device 102, the communication devices 102 and 103 also establish a Link via 36ch and start data communication (S507).

[0050] In addition, when the communication device 102 indicates approval in S505 for the request information requested by the communication device 103 in S504, the process of S506 is similarly performed. Also, when the request information transmitted by the communication device 103 in S504 includes the request information regarding the Link via 36ch, the process of S507 is performed.

[0051] In this embodiment, two Links are established by transmitting and receiving frames in one frequency channel, but it is not limited to this, and three or more Links may be established.

[0052] In addition, in this embodiment, a case where multi-link communication is started between communication devices 102 and 103 from a state where a link has not yet been established is shown, but the present invention is not limited to this. The communication devices 102 and 103 may start multi-link communication by establishing a new link in addition to the already established link. In this case, if the communication device 103, which is a STA, has already acquired the capability information regarding the multi-link communication of the communication device 102, which is an AP, the process may start from S504. Alternatively, if the communication device 102 has already acquired the capability information regarding the multi-link communication of the communication device 103, the communication device 102 may send a signal for causing the communication device 103 to transmit an Association Request, so that the process can start from S504. Alternatively, the communication devices 102 and 103 may newly establish a link in addition to the already established multiple links. In these cases, the sequence in FIG. 5 may start from S504.

[0053] In addition, in this embodiment, a case where a link via a plurality of frequency channels is established by transmitting and receiving frames in one frequency channel is shown, but the present invention is not limited to this. When performing multi-link communication, the communication devices 102 and 103 may disconnect the links via the already established multiple frequency channels by transmitting and receiving frames via one frequency channel.

[0054] As described above, as shown in FIG. 5, the communication devices 102 and 103 can control the establishment and disconnection of links in other frequency channels by transmitting and receiving frames via a certain frequency channel (or link). In addition, the communication devices 102 and 103 can control the establishment or disconnection of links in a plurality of frequency channels by transmitting and receiving frames via a certain frequency channel (or link).

[0055] Similarly, the communication devices 102 and 104 to 106 can also control the establishment and disconnection of links in other frequency channels by transmitting and receiving frames via a certain frequency channel (or link).

[0056] Also, in the sequence of FIG. 5, the sender may include its own MLD (Multi-Link Device) MAC Address in at least one of the management frames transmitted in S501 to S505 described above. The MLD MAC Address is identification information of a communication device capable of performing Multi-Link communication. Also, the sender may include its own MLD MAC Address in at least one of the frames other than the management frames transmitted in S501 to S505.

[0057] FIG. 6 is a flowchart showing the flow of processing performed when the control unit 302 executes the program stored in the storage unit 301 of the communication device 102. In the present embodiment, an example of determining the frequency channel for transmitting a frame when the determination of the frequency channel has not been completed is shown.

[0058] This flowchart starts when the communication device 102 transmits a Group Addressed Frame. Alternatively, this flowchart may be started when the connection form between the communication device 102 and another communication device changes. When the connection form changes, for example, when a new Link connection starts with another communication device, or when the connection with another communication device is disconnected.

[0059] First, the communication device 102 determines, as the frequency channel for transmitting the frame, the frequency channel on which a connection is established with a non-MLD STA among the frequency channels on which a connection is established with the STA. That is, it adds to the transmission frequency channel group (S601). Here, an MLD is a communication device capable of performing parallel communication with a partner device via a plurality of frequency channels. In the present embodiment, since all of the communication devices 103 to 106 are MLDs, no frequency channel is added to the transmission frequency channel group here.

[0060] Next, the communication device 102 determines the STAs connected to the communication device 102 on a single frequency channel, and determines that frequency channel as the frequency channel for transmitting frames. That is, it is added to the transmission frequency channel group (S602). Hereinafter, a method for determining the STAs that have established a connection with the communication device 102 via a single frequency channel is shown. The communication device 102 has acquired the MLD MAC Addresses of the communication devices 103 to 106 at the time of connection establishment or the like in each of the frequency channels through which the connections with the communication devices 103 to 106 are established. Based on the configuration example shown in FIG. 2, for example, since the communication device 103 has established a connection with the communication device 102 via channels 1 and 48, the communication device 102 has acquired two MLD MAC Addresses from the communication device 103. Therefore, the communication device 103 is not an STA that has established a connection with the communication device 102 via a single frequency channel. On the other hand, for example, since the communication device 106 has established a connection with the communication device 102 only on channel 100, the communication device 102 has acquired one MLD MAC Address of the communication device 106.

[0061] As described above, in this embodiment, the MLD MAC Address acquired at the time of connection establishment is used, but it is not limited to this, and the MLD MAC Address acquired at another timing may be used to search for the corresponding MLD. For example, in S602, the MLD MAC Address of the communication device establishing a connection via each frequency channel may be inquired of the communication device establishing the connection.

[0062] In the configuration example shown in FIG. 2, the communication device 102 and the communication device 105 have established a connection via channels 48 and 100, and the communication device 102 and the communication device 106 have established a connection via channel 100. In FIG. 2, since the communication device 102 and the communication device 105, and the communication device 102 and the communication device 106 have established connections via channel 100, which is the same frequency channel, frames are transmitted to channel 100.

[0063] For example, assume that communication device 102 and communication device 105 establish a connection via a single frequency channel, communication device 102 and communication device 106 establish a connection via two different frequency channels, and the three frequency channels are all different. When the three aforementioned frequency channels are all different, a frame is transmitted on a single frequency channel. As described above, by determining the frequency channel for transmitting the frame, the number of frequency channels for transmitting the frame can be suppressed, and the frame can be reliably transmitted even to the STA that has established a connection via a single frequency channel.

[0064] Next, communication device 102 determines whether the determination of the transmission frequency channel group has been completed (S603). Since this determination method will be described later with reference to FIG. 7, the description is omitted here. If it has been completed (YES in S603), the flow of determining the transmission frequency channel group ends.

[0065] In S603, if the determination of the transmission frequency channel group has not been completed, communication device 102 acquires the STAs to which the frame cannot be transmitted even if the frame is transmitted on the frequency channels determined in S601 and 602 (S604). Based on the configuration example shown in FIG. 2, since it is determined in S602 that the frame is to be transmitted on 100ch, the frame is transmitted to communication devices 105 and 106. However, since the frame is not transmitted to communication devices 103 and 104, the STAs acquired in S604 are communication devices 103 and 104.

[0066] Next, the communication device 102 adds the frequency channel that can transmit frames to the most STAs among the STAs acquired in S604 to the transmission frequency channel group (S605). That is, among the frequency channels in which the communication device 102 and the STAs acquired in S604 have established a connection, if there is the same frequency channel, frames are transmitted to that frequency channel. Based on the configuration example shown in FIG. 2, the communication device 103 and the communication device 104 have established a connection on channel 1, and when frames are transmitted on channel 1, the frames are transmitted to the most communication devices. Therefore, channel 1 is added to the transmission frequency channel group. That is, since the communication device 102 and the communication device 103, and the communication device 102 and the communication device 104 have each established a connection via channel 1 which is the same frequency channel, frames are transmitted to channel 1.

[0067] When the frequency channel for transmitting frames is determined in S605, that is, when it is added to the transmission channel group, it is determined whether the determination of the frequency channel for transmitting frames in S603 is completed. In this embodiment, based on the configuration example shown in FIG. 2, when frames are transmitted on the transmission frequency channel group of channels 1 and 100, since it is possible to transmit frames to the communication devices 103 to 106, the transmission frequency channel group determination flow ends.

[0068] When there are multiple frequency channels that can be transmitted to the most STAs, one may be randomly selected, or one may be selected based on the order of the channel numbers of the frequency channels, or one may be selected by another determination method. As another determination method, it may be determined to avoid the frequency channels in which the STA is operating in the power save state, the frequency channels with high congestion, or the frequency channels that are non-STR (Simultaneous Transmit Receive).

[0069] FIG. 7 is a flowchart showing the flow of processing performed when the control unit 302 executes a program stored in the storage unit 301 of the communication device 102. In this flowchart, when the communication device 102 transmits a Group Addressed Frame to the communication devices 103 to 106, it determines whether the determination of the frequency channel group for transmitting the Group Addressed Frame is completed.

[0070] The communication device 102 acquires a first MAC address group, which is the MAC address of the STA with which a connection is established on the frequency channel determined to transmit the frame (S701). In this embodiment, the MLD MAC address is used as the MAC address of the STA.

[0071] Next, the communication device 102 acquires a second MAC address group, which is the MAC address of all STAs with which connections are established on all frequency channels (S702). Note that the first MAC address group and the second MAC address group are not at the timing of determining whether the determination of the frequency channel group for transmitting the frame is completed, and the first MAC address group may be acquired in advance. For example, the first MAC address group may be acquired when a new connection is established with the STA or when the connection is disconnected.

[0072] Next, the communication device 102 determines whether the first MAC address group matches the second MAC address group (S703). If it is determined in S703 that the first MAC address group matches the second MAC address group, the communication device 102 determines that the determination of the transmission frequency channel group is completed (S704). When it is determined by S704 that the determination of the frequency channel for transmitting the frame is completed, the frame is not transmitted on the frequency channels other than the determined transmission frequency channel group, and the flow of determining the transmission frequency is terminated.

[0073] When it is determined in S703 that the first MAC address group and the second MAC address group do not match, the communication device 102 determines that the determination of the transmission frequency channel group is incomplete, and ends this flowchart (S705).

[0074] According to this embodiment, the communication device 102 can determine the frequency channel for transmitting a frame based on the frequency channel to which a STA that has not established a connection with the determined frequency channel for transmitting a frame and the number of frequency channels to which the STA has established a connection. Furthermore, by determining the frequency channel for transmitting a frame as described above, the number of frequency channels for transmitting a frame can be suppressed.

[0075] In addition, although an example of determining completion using the MAC address is given in FIG. 7, the present invention is not limited to this, and Multi-Link information shared when the AP and the STA establish a connection may be used. Also, the completion of determining the frequency channel for transmitting a frame may be determined using the MAC address of the STA.

[0076] In the above-described embodiment, an example in which a communication device having the hardware configuration of FIG. 3 executes the flowcharts of FIGS. 6 to 11 is shown. However, a wireless chip having a storage unit, a control unit, and a communication unit in FIG. 3 may execute the flowcharts of FIGS. 6 to 11. That is, the communication device of this embodiment may be a wireless chip having a storage unit, a control unit, and a communication unit in FIG. 3.

[0077] In addition, a recording medium storing a program code of software for realizing the above functions may be supplied to a system or a device, and a computer (CPU, MPU) of the system or the 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 realizes the functions of the above-described embodiment, and the storage medium storing the program code constitutes the above-described device.

[0078] As a storage medium for supplying program code, for example, a flexible disk, a hard disk, an optical disk, a magneto-optical disk, a CD-ROM, a CD-R, a magnetic tape, a non-volatile memory card, a ROM, a DVD, etc. can be used.

[0079] In addition, by executing the program code read by the computer, not only the above-described functions are realized, but also based on the instructions of the program code, the OS running on the computer performs part or all of the actual processing, and the above-described functions may be realized. The OS is an abbreviation for Operating System.

[0080] Furthermore, the program code read from the storage medium is written into the memory provided in a function expansion board inserted into the computer or a function expansion unit connected to the computer. Then, based on the instructions of the program code, the CPU provided in the function expansion board or the function expansion unit performs part or all of the actual processing, and the above-described functions may be realized.

[0081] The present invention can also be realized by supplying a program that realizes one or more functions of the above-described embodiments to a system or device via a network or a storage medium, and having one or more processors in the computer of the system or device read and execute the program. It can also be realized by a circuit (for example, an ASIC) that realizes one or more functions.

Explanation of Signs

[0082] 301 Storage unit 302 Control unit 303 Functional unit 304 Input unit 305 Output unit 306 Communication unit 307 Antenna

Claims

1. A communication device, establishing means for establishing a connection between the communication device and a first other communication device via one or more links, and establishing a connection between the communication device and a second other communication device via one or more links; determining means for determining, among a plurality of frequency channels used in the links established by the establishing means, a frequency channel necessary for a frame transmitted by multicast communication or broadcast communication to reach the first other communication device and the second other communication device; transmitting means for transmitting the frame in the frequency channel determined by the determining means, and having, wherein the establishing means has established a connection between the communication device and the first other communication device via a first frequency channel and a second frequency channel, and the communication device and the second other communication device have established a connection via a third frequency channel and a fourth frequency channel, when the first frequency channel and the third frequency channel are the same frequency channel, the determining means determines to transmit the frame in the first frequency channel and the third frequency channel, transmitting the frame in the first frequency channel and the third frequency channel determined by the determining means A communication device characterized by the above.

2. A communication device, establishing means for establishing a connection between the communication device and a first other communication device via one or more links, and establishing a connection between the communication device and a second other communication device via one or more links; determining means for determining, among a plurality of frequency channels used in the links established by the establishing means, a frequency channel necessary for a frame transmitted by multicast communication or broadcast communication to reach the first other communication device and the second other communication device; transmitting means for transmitting the frame in the frequency channel determined by the determining means, and having, wherein the establishing means has established a connection between the communication device and the first other communication device via a first frequency channel, and the communication device and the second other communication device have established a connection via a second frequency channel and a third frequency channel, When the first frequency channel and the second frequency channel are the same frequency channel, the determining means determines the first frequency channel and the second frequency channel as the frequency channel for transmitting the frame. When the first frequency channel, the second frequency channel, and the third frequency channel are different frequency channels, the determining means determines either one of the second frequency channel and the third frequency channel and the first frequency channel as the frequency channel for transmitting the frame. Transmitting the frame on the frequency channel determined by the determining means. A communication device characterized by the above.

3. When the first frequency channel, the second frequency channel, and the third frequency channel are different frequency channels, the determining means determines to transmit the frame on the third frequency channel when the second frequency channel is a frequency channel on which another second communication device operates in a power save state or a frequency channel with high congestion. The communication device according to claim 2.

4. The communication device according to any one of claims 1 to 3, wherein the frame is a Group Addressed Frame.

5. The communication device according to any one of claims 1 to 4, wherein the communication device performs communication conforming to the IEEE802.11 standard series.

6. A control method for a communication device, comprising: An establishing step of establishing a connection between the communication device and a first other communication device via one or more links, and establishing a connection between the communication device and a second other communication device via one or more links; A determining step of determining, among a plurality of frequency channels used in the link established by the establishing step, the frequency channel necessary for a frame transmitted by multicast communication or broadcast communication to reach the first other communication device and the second other communication device; A transmitting step of transmitting the frame on the frequency channel determined by the determining step. By the establishment process, the communication device and the first other communication device have established a connection via a first frequency channel and a second frequency channel, and the communication device and the second other communication device have established a connection via a third frequency channel and a fourth frequency channel. In this state, When the first frequency channel and the third frequency channel are the same frequency channel, in the determination process, it is determined to transmit the frame on the first frequency channel and the third frequency channel. A method for controlling a communication device, characterized by transmitting the frame on the first frequency channel and the third frequency channel determined by the determination process. **Claim 7**: A method for controlling a communication device, An establishment process in which the communication device and a first other communication device establish a connection via one or more links, and the communication device and a second other communication device establish a connection via one or more links. A determination process of determining, among a plurality of frequency channels used in the links established by the establishment process, the frequency channels necessary for a frame transmitted by multicast communication or broadcast communication to reach the first other communication device and the second other communication device. A transmission process of transmitting the frame on the frequency channel determined by the determination process, and having By the establishment process, the communication device and the first other communication device have established a connection via a first frequency channel, and the communication device and the second other communication device have established a connection via a second frequency channel and a third frequency channel. In this state, When the first frequency channel and the second frequency channel are the same frequency channel, in the determination process, the first frequency channel and the second frequency channel are determined as the frequency channels for transmitting the frame. When the first frequency channel, the second frequency channel, and the third frequency channel are different frequency channels, either one of the second frequency channel and the third frequency channel and the first frequency channel are determined as the frequency channels for transmitting the frame. Transmitting the frame on the frequency channel determined by the determination process A method for controlling a communication device, characterized by this. **Claim 8** A program for causing a computer to function as the communication device according to any one of claims 1 to 5.

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