Communication device, communication method, and program

Abstract

The communication device (100) operating as an access point transmits a frame having first information and second information to the communication devices (104, 105, 106) operating as access points, the first information indicating that information about the device is transmitted to the communication device (100), the second information indicating RUs in turn used by the communication devices (104, 105, 106) to transmit the first information, and receives response frames including information about the communication devices (104, 105, 106) in parallel with the RUs indicated by the second information in response to the transmission of the frame using Orthogonal Frequency Division Multiple Access (OFDMA).

Description

Technical Field

[0001] This invention relates to communication devices and methods for wireless communication. Background Technology

[0002] With the recent increase in the amount of data to be communicated, communication technologies such as Wireless Local Area Networks (LANs) have been developed. The Institute of Electrical and Electronics Engineers (IEEE) 802.11 standard series is known as the primary communication standard for wireless LANs. The IEEE 802.11 standard series includes IEEE 802.11a / b / g / n / ac / ax standards.

[0003] In IEEE 802.11ax, described in Patent Document 1, a technique for providing peak throughput of up to 9.6 gigabits per second (Gbps) and improving communication speeds in congested conditions via Orthogonal Frequency Division Multiple Access (OFDMA) is standardized. Note that OFDMA stands for Orthogonal Frequency Division Multiple Access.

[0004] As a successor standard aimed at further improving throughput, frequency utilization efficiency, and communication latency, a task force was formed to develop the IEEE 802.11be standard (hereinafter referred to as 11be).

[0005] In 11be, the following techniques were studied: enabling multiple access points (APs) to operate collaboratively and communicate data with stations (STAs) to improve communication performance, such as increasing communication rates and using beamforming to reduce radio wave interference.

[0006] An example of cooperative operation among multiple access points (APs) is distributed MIMO (Multiple-Input Multiple-Output) technology, where multiple transmit and receive antennas are used simultaneously in the same channel. In distributed MIMO, in an environment where multiple APs and multiple STAs coexist, information about the communication state and the state of each AP is shared among the APs, and data is transmitted from each AP to the STA at the same timing. Compared to communication by a single AP, this cooperative operation among multiple APs allows for an increase in the number of spatial streams. Therefore, throughput is expected to be improved.

[0007] The aforementioned communication technology, which involves multiple access points (APs) cooperating, is called multi-AP communication. APs are classified as master APs, which manage other APs, and slave APs, which operate under the management of the master AP.

[0008] Reference List

[0009] Patent documents

[0010] PTL 1: Japanese Patent Application Publication No. 2018-50133 Summary of the Invention

[0011] Technical issues

[0012] In multi-AP communication, it is best to identify the slave APs participating in the communication from among the APs present near the master AP before the AP transmits data to the STA. To identify the slave APs, it is best to receive information from the APs present near the master AP, such as congestion status and information indicating whether they participate in multi-AP communication. However, if there are multiple APs near the master AP, and the master AP communicates with multiple APs one-to-one in turn, it will take a long time to receive information from all APs.

[0013] Therefore, the present invention aims to reduce the time required for a communication device operating as an access point to receive necessary information from multiple communication devices operating as access points.

[0014] Technical solutions to the problem

[0015] According to one aspect of the present invention, a communication device is provided that operates as an access point in a communication network, the communication device comprising: a generating unit that generates a frame including first information and second information, the first information indicating that the communication device requests each of a plurality of other communication devices configured to operate as an access point in the communication network to transmit information about itself, the second information indicating frequency components available to the plurality of other communication devices; a transmitting unit that transmits the frame generated by the generating unit to each of the plurality of other communication devices; and a receiving unit that receives, in parallel using Orthogonal Frequency Division Multiple Access (OFDMA), response frames transmitted from each of the plurality of other communication devices in response to the frame with the frequency components indicated by the second information, the response frames including information about each of the plurality of other communication devices.

[0016] According to another aspect of the present invention, a communication device is provided that operates as an access point in a communication network. The communication device includes: a generating unit that generates a frame including first information and second information, the first information indicating that the communication device requests each of a plurality of other communication devices configured to operate as access points in the communication network to transmit data, and the second information indicating frequency components available to the communication device configured to operate as access points; a transmitting unit that transmits the frame generated by the generating unit to each of the plurality of other communication devices; and a receiving unit that receives, in parallel using Orthogonal Frequency Division Multiple Access (OFDMA), response frames transmitted from each of the plurality of other communication devices in response to the frame at the frequency components indicated by the second information, the response frames including information about each of the plurality of other communication devices.

[0017] According to another aspect of the present invention, a communication device is provided that operates as an access point in a communication network, the communication device comprising: a receiving unit that receives from another communication device a frame including first information and second information, the first information indicating that the other communication device, configured to operate as an access point in the communication network, requests the communication device to send information about its own device, and the second information indicating frequency components available to the communication device; and a transmitting unit that uses Orthogonal Frequency Division Multiple Access (OFDMA) to transmit a response frame including information about the communication device at the frequency components indicated by the second information, as a response to the frame received by the receiving unit.

[0018] According to another aspect of the present invention, a communication device is provided that operates as an access point in a communication network. The communication device includes: a receiving unit that receives from another communication device a frame including first information and second information, the first information indicating that the other communication device, operating as an access point in the communication network, requests the communication device to send data, and the second information indicating frequency components available to the communication device, operating as the access point; and a transmitting unit that uses Orthogonal Frequency Division Multiple Access (OFDMA) to transmit in parallel response frames including information about the communication device at the frequency components indicated by the second information, as a response to the frame received by the receiving unit.

[0019] Beneficial effects of the present invention

[0020] According to the present invention, a communication device sends frames including first information and second information to a plurality of other communication devices, and uses OFDMA to receive responses from the plurality of other communication devices in parallel, thereby reducing the time required to receive necessary information from the plurality of other communication devices. The first information is used by the communication device to instruct the plurality of other communication devices to send information about their own devices, and the second information indicates the frequency components assigned to each of the plurality of other communication devices. Attached Figure Description

[0021] [ Figure 1 ] Figure 1 This is a diagram showing the structure of the network to which the communication device 102 belongs.

[0022] [ Figure 2 ] Figure 2 This is a block diagram showing the hardware structure of communication devices 102 to 106.

[0023] [ Figure 3 ] Figure 3 This is a diagram illustrating an example of the trigger frame format.

[0024] [ Figure 4 ] Figure 4This is a diagram showing an example of the frame format of the response frame to the trigger frame.

[0025] [ Figure 5 ] Figure 5 This is a flowchart illustrating the processes to be performed by the communication device 100, which is the main AP, in an exemplary embodiment of the present invention.

[0026] [ Figure 6 ] Figure 6 It is used by communication device 100 to determine the sequence diagram from AP.

[0027] [ Figure 7 ] Figure 7 It is used by communication device 100 to determine the sequence diagram from AP.

[0028] [ Figure 8 ] Figure 8 It is used by communication device 100 to determine the sequence diagram from AP.

[0029] [ Figure 9 ] Figure 9 The size of the RU allocated by the AP in a 20MHz bandwidth is shown. Detailed Implementation

[0030] Exemplary embodiments of the present invention will now be described in detail with reference to the accompanying drawings. Note that the constructions described in the following exemplary embodiments are merely examples, and the present invention is not limited to the constructions shown.

[0031] Figure 1 The diagram illustrates the construction of a communication network built by communication device 100 according to an exemplary embodiment of the present invention. Communication device 104 is an access point (hereinafter referred to as AP) that includes the function of building a wireless communication network 101. Communication device 105 is an AP that includes the function of building a wireless communication network 102. Communication device 106 is an AP that includes the function of building a wireless communication network 103. Each of communication devices 107 and 108 is a station (hereinafter referred to as STA) that includes the function of participating in wireless communication networks 101, 102, and 103. In this exemplary embodiment, communication device 100 serves as a master AP that manages other APs, and communication devices 104 to 106 are APs located near the master AP. Sub-APs are determined from communication devices 104 to 106.

[0032] Communication devices 100 and 104 through 108 are configured to perform wireless communication conforming to the IEEE 802.11be standard. Note that IEEE stands for the Institute of Electrical and Electronics Engineers. Communication devices 104 through 108 are configured to communicate in the frequency bands of 2.4 GHz, 5 GHz, and 6 GHz. Communication devices 100 and 104 through 108 are configured to communicate with bandwidths of 20 MHz, 40 MHz, 80 MHz, 160 MHz, and 320 MHz.

[0033] Communication devices 100 and 104 to 108 perform OFDMA communication conforming to the IEEE 802.11be standard, thereby enabling multi-user (MU) communication that multiplexes multiple user signals. OFDMA stands for Orthogonal Frequency Division Multiple Access. In OFDMA communication, resource units (RUs), which are part of the divided frequency components, are uniquely allocated to each communication device, and the carriers from the STAs are orthogonal to each other. Therefore, each AP can communicate in parallel with multiple communication devices.

[0034] Note that communication devices 100 and 104 to 108 comply with the IEEE 802.11be standard, and may also comply with conventional standards that preceded the IEEE 802.11be standard. Specifically, communication devices 100 and 104 to 108 may comply with at least one of the IEEE 802.11a / b / g / n / ac / ax standards. Communication devices 100 and 104 to 108 may comply not only with the IEEE 802.11 series of standards, but also with other communication standards, such as... Near Field Communication (NFC), Ultra Wideband (UWB), ZigBee, and the Multiband OFDM Alliance (MBOA). Note that NFC stands for Near Field Communication. UWB stands for Ultra Wideband. MBOA stands for Multiband OFDM Alliance. UWB includes Wireless USB, Wireless 1394, and WiNET. Communication devices 100 and 104 to 108 can conform to communication standards such as wired LAN.

[0035] Specific examples of communication devices 100 and 104-106 include wireless LAN routers and personal computers (PCs). However, communication devices 100 and 104-106 are not limited to these examples. Communication devices 104-106 can be information processing devices, such as wireless chips, configured to perform wireless communication compliant with the IEEE 802.11be standard. Specific examples of communication devices 107 and 108 include cameras, tablets, smartphones, PCs, mobile phones, and camcorders. However, communication devices 107-108 are not limited to these examples. Communication devices 107 and 108 can be information processing devices, such as wireless chips, configured to perform wireless communication compliant with the IEEE 802.11be standard. Although Figure 1The wireless network shown includes three APs and two STAs, but the number of APs and STAs is not limited to this example.

[0036] Figure 2 The hardware configuration of communication devices 100 and 104 to 108 according to this exemplary embodiment is shown. Communication device 100 includes a storage unit 201, a control unit 202, a functional unit 203, an input unit 204, an output unit 205, a communication unit 206, and an antenna 207.

[0037] Storage unit 201 comprises one or more memories, such as read-only memory (ROM) and random access memory (RAM), and stores programs for performing the various operations described below, as well as various information such as communication parameters for wireless communication. ROM stands for read-only memory, and RAM stands for random access memory. Note that storage unit 201 can use not only memories such as ROM and RAM, but also storage media such as floppy disks, hard disks, optical disks, magneto-optical disks, CD-ROMs, CD-Rs, magnetic tapes, non-volatile memory cards, and DVDs. Storage unit 201 may include multiple memories.

[0038] The control unit 202 comprises one or more processors, such as a central processing unit (CPU) and a microprocessor unit (MPU). It executes a computer program stored in storage unit 201, thereby controlling the entire communication device 100. The CPU represents the central processing unit, and the MPU represents the microprocessor unit. Note that the control unit 202 can control the entire communication device 100 by having an operating system (OS) and the computer program stored in storage unit 201 operate collaboratively. The control unit 202 generates data and signals to be transmitted in communications with other communication devices. The control unit 202 may include multiple processors, such as multi-core processors, and multiple processors can control the entire communication device 100.

[0039] Control unit 202 controls function unit 203 to perform predetermined processes such as imaging, printing, or projection. Function unit 203 is hardware used by each AP and each STA to perform predetermined processes. For example, if each AP and each STA is used as a camera, then function unit 203 is an imaging unit and performs imaging processing. For example, if each AP and each STA is used as a printer, then function unit 203 is a printing unit and performs printing processing. For example, if each AP and each STA is used as a projector, then function unit 203 is a projection unit and performs projection processing. The data to be processed by function unit 203 may be data stored in storage unit 201 or data communicated with other APs and STs via communication unit 206, which will be described below.

[0040] Input unit 204 receives various operations from the user. Output unit 205 performs various output processing on the user via a monitor screen or speaker. In this case, the output processing performed by output unit 205 may include vibration output, display on the monitor screen, and audio output via speaker. Note that input unit 204 and output unit 205 can be implemented as a single module, such as a touch panel. Input unit 204 and output unit 205 can be integrated with communication device 100 or can be separate from communication device 100.

[0041] Communication unit 206 controls wireless communication conforming to the IEEE 802.11 series standards. Communication unit 206 can also control wired communication via wired LAN, etc. Communication unit 206 controls antenna 207 and transmits and receives signals for wireless communication generated by control unit 202. Note that if communication device 100 conforms not only to the IEEE 802.11be standard but also to the Near Field Communication (NFC) standard... If the communication device 100 is configured to perform wireless communication conforming to multiple communication standards, it may include communication units and antennas conforming to each standard. The communication device 100 communicates with communication devices 107 and 108 via communication unit 206 for data such as image data, document data, and video data.

[0042] Figure 3 An example of the format of a trigger frame in this exemplary embodiment is shown. A trigger frame is a frame used to prompt each STA to send data to each AP using the RUs allocated to the STAs by each AP. Each STA uses the RUs allocated by each AP, which allows each STA to send data to the APs in parallel.

[0043] Figure 9 The size of the RU to be allocated by each AP is shown. Note that... Figure 9 This illustrates the RU allocation when communication device 100 uses a 20MHz bandwidth. The RU allocation is described in the RU allocation subfield below. Figure 9 The diagram shows the RU allocation. 901 indicates the size of the RU to be allocated to nine STAs. RUs are obtained by dividing 20MHz into 256 subcarriers on the frequency axis and collecting multiple subcarriers from the divided subcarriers. In this case, the size of the RU allocated by the AP to each STA is "26". The size of the RU indicates the number of subcarriers to be used for each RU. The RU size "26" indicates the use of 26 subcarriers. Note that 902 indicates the size of the RU to be allocated to five STAs, 903 indicates the size of the RU to be allocated to three STAs, and 904 indicates the size of the RU to be allocated to one STA.

[0044] In this exemplary embodiment, Figure 3 The diagram illustrates a frame being transmitted from communication device 100 to each of communication devices 104 to 106, which are APs located near communication device 100 (hereinafter referred to as neighboring APs). The frame indicates the transmission of information about communication devices 104 to 106. In this context, a neighboring AP refers to an AP located within range from which communication device 100 can receive beacon frames.

[0045] Figure 3 The fields and subfields 301 to 313 shown are based on the format specified in IEEE 802.11ax. Trigger type 309 in common information 305 specifies the trigger type of the trigger frame. Length 310 indicates the common communication period for all communication devices. BW 311 is a field that includes information indicating the bandwidth of the channel to be used when sending data from each neighboring AP to the main AP. For example, suppose BW 311 includes "0", "1", and "2" as subfield values, and the corresponding frequency bands are 20MHz, 40MHz, and 80MHz, respectively. In this case, a subfield value of "1" in BW 311 indicates that the available frequency bandwidth for each neighboring AP is 40MHz. If a subfield value in BW 311 is greater than or equal to "1", then when sending information about neighboring APs to communication device 100, each neighboring AP can use the frequency bandwidth corresponding to that value to send information. For example, if the value of BW 311 indicates "2", then each neighboring AP can use bandwidths of 20MHz, 40MHz, and 80MHz to send information.

[0046] Table 1 shows the correspondence between the values ​​of each trigger type subfield in trigger type 309 and each trigger type.

[0047] [Table 1]

[0048] Subfield value Trigger type 0 Base 1 Beamforming Report Polling (BFRP) 2 MU-BAR 3 MU-RTS 4 Cache Status Report Polling (BSRP) 5 GCR MU-BAR 6 Bandwidth Query Report Polling (BQRP) 7 NDP Feedback Reporting Polling (NFRP) 8 Multiple AP groups form trigger frames 9-15 reserve

[0049] The trigger type is represented by four bits. In this exemplary embodiment, the subfield value "8" in the trigger type indicates that each neighboring AP will send information about its own device to the master AP.

[0050] User information 306#1 to 306#N each includes an RU allocation 313 and an associated ID (AID) 312 as an identifier. Each AID 312 is represented by 12 bits. When the AID, which is the identification information assigned during connection establishment, is stored in AID 312, the lower 12 bits of the AID are stored. Therefore, Table 2 shows the subfields in AID 312 as AID12 subfields. AID 312 will be described below with reference to Table 2.

[0051] In RU allocation 313, RUs are allocated as frequency components to be used to send information about each neighboring AP to the master AP. (As described above...) Figure 9 The specific RU allocation method is illustrated. There are two types of RUs: RUs that can only be used by communication devices whose last 12 bits of the AID value, which is the identification information assigned during connection establishment, match the AID subfield value; and Random Access Resource Units (RA-RUs) that can be used by multiple communication devices. It can be assumed that RA-RUs are allocated to, for example, communication devices that have not established a connection and have not been assigned an AID, communication devices that have established a connection and have resumed from sleep, or communication devices with low priority.

[0052] Table 2 shows the relationship between the subfield value of AID 312 in user information 306 and the definition of that value.

[0053] [Table 2]

[0054]

[0055] Note that the STAs shown in Table 2 also include APs. Each neighboring AP determines whether the user information is specific to its own device based on the identification information corresponding to the value stored in the AID12 subfield.

[0056] The value "1-2007" in the AID12 subfield indicates user information for STAs whose last 12 digits of the AID assigned during connection establishment match the value of the AID12 subfield. The value "2045" in the AID12 subfield indicates user information for STAs that have not established a connection and have not been assigned an AID. The value "2047" in the AID12 subfield is a newly specified field value. The value "2047" in the AID12 subfield indicates user information for APs that have not established a connection and have not been assigned an AID.

[0057] If the communication device 100 has established a connection with each of the neighboring APs, it includes multiple user information entries 306#1 to 306#N corresponding to the number of neighboring APs. However, if the communication device 100 has not established a connection with each of the neighboring APs, it shares user information with the value "2045" or "2047" stored in the AID12 subfield.

[0058] In addition, communication device 100 manages OFDMA Random Access Back-Off (OBO), which acts as a timer to prevent neighboring APs from competing for the use of RUs or RA-RUs allocated by communication device 100. OBOs are randomly allocated by communication device 100. If the value obtained by subtracting the number of RA-RUs allocated by communication device 100 from the initial value of the OBO is equal to or less than the number of RA-RUs allocated by communication device 100, then each neighboring AP sends a response frame using the allocated RA-RUs. If the value obtained by subtracting the number of RA-RUs allocated by communication device 100 from the initial value of the OBO is greater than the number of RA-RUs allocated by communication device 100, then the number of neighboring APs is reduced by the number of RA-RUs allocated by communication device 100, and the neighboring APs wait for subsequent transmission of trigger frames.

[0059] In this exemplary embodiment, if the communication device 100 and each neighboring AP have not established a connection, the communication device 100 sets the trigger type subfield value to "8" to instruct each neighboring AP to send information about its own device to the communication device 100. Furthermore, the communication device 100 sets the AID12 subfield value to "2045" or "2047" to allocate RUs for each neighboring AP to send information. If the communication device 100 and each neighboring AP have not established a connection, the AID is not assigned to a neighboring AP. Therefore, the communication device 100 sets the AID12 subfield value to "2045" or "2047" so that neighboring APs can use RA-RUs to send information. If the AID12 subfield value is set to "2045", then as shown in Table 2, STAs without established connections can also be used, allowing neighboring APs to compete with STAs for the RA-RUs they need to use. However, if the AID12 subfield value is set to "2047", then this field indicates that the RA-RU can only be used by APs without established connections, allowing neighboring APs to use the RA-RU without competing with STAs.

[0060] Furthermore, once a connection has been established between the communication device 100 and each neighboring AP, the communication device 100 sets the trigger type subfield value to "8" to indicate that information about each neighboring AP is sent to the communication device 100. Additionally, the communication device 100 sets the AID12 subfield value to the last 12 bits of the AID value assigned during connection establishment to allocate a RU (Resource Unit) for neighboring APs to send information about their own devices.

[0061] Furthermore, when no connection has been established between communication device 100 and any of the neighboring APs, and when the trigger type subfield value is set to "0" and the AID12 subfield value is set to "2047", this frame instructs the neighboring APs to send information about their own devices to communication device 100. In the IEEE 802.11ax standard, if the trigger type subfield value is set to "0" and the AID subfield value shown in Table 2 (0-2046) is stored, the frame instructs the transmission of an uplink multi-user (UL MU). However, this can be interpreted as the frame instructing the neighboring APs to send information about their own devices to communication device 100 when the trigger type subfield value is set to "0" and the newly designated AID12 subfield value ("2047") is stored.

[0062] When the communication device 100 sends a trigger frame, the communication device 100 can select the trigger type subfield value according to the connection status of each neighboring AP, or the user can set the trigger type subfield value. For example, if there is a neighboring AP with which a connection has been established, the trigger type subfield value can be set to "8", while if there is no neighboring AP with which a connection has been established, the trigger type subfield value can be set to "0".

[0063] Figure 4 The action field format of a multi-AP group forming a response frame is shown as an example of a response frame to a trigger frame in this exemplary embodiment. This response frame conforms to the format of a management frame, such as an action frame.

[0064] BSSID2 409 includes information about the BSSIDs of each neighboring AP, and cache state 410 includes information about the cache state of each neighboring AP. The master AP can identify the data accumulation status in the caches of each neighboring AP based on the cache state. Information indicating whether to participate in multi-AP can be stored in multi-AP participation 411. The number of STAs that have established connections with neighboring APs is stored in the number of STAs 412, and a list of AIDs assigned to the STAs that have established connections is stored in the AID list 413. In addition, information about the strength of the received trigger frame is stored in the trigger frame signal strength 414. The distance between the communication device 100 and each neighboring AP can be identified based on the trigger frame signal strength 414. The communication device 100 determines the AP based on the information about the response frame of the trigger frame.

[0065] Figure 5This is a flowchart illustrating the processing flow in which the control unit 202 executes a program stored in the storage unit 201 of the communication device 100, which serves as the master AP. The flowchart shows a processing flow in which the communication device 100 sends a trigger frame to instruct each neighboring AP to send information about its own device, and determines the source AP based on information about the received response frames.

[0066] This flowchart begins when the wireless LAN function is activated, for example, when a user configures communication device 100 for multi-AP communication, when communication device 100 is powered on, or when the wireless LAN function of communication device 100 is enabled. Alternatively, this flowchart may begin when communication device 100 cannot receive any beacon frames from slave APs, for example, when multi-AP communication has been established but the slave AP with which it was communicating has moved out of communication range.

[0067] In step S501, the communication device 100 monitors beacon frames sent from each neighboring AP. Next, in step S502, the communication device 100 determines whether a beacon frame sent from a neighboring AP has been received. If a beacon frame is received in step S502, then in step S503, it is determined whether a predetermined time has elapsed. After the predetermined time has elapsed, multiple beacon frames can be received. If no beacon frame is received in step S502, the process returns to step S501 to monitor beacon frames from each neighboring AP again. In step S503, if the predetermined time has not yet elapsed, the process returns to step S501 again to monitor beacon frames from each neighboring AP. If the predetermined time has elapsed in step S503, then in step S504, the communication device 100 receives a beacon frame and determines whether two or more neighboring APs are detected. The number of neighboring APs is managed within the functional unit of the communication device 100. If two or more neighboring APs exist, in step S505, the communication device 100 sends a trigger frame to the neighboring APs from which it received the beacon frame. This trigger frame includes information instructing the neighboring APs to send information about their own devices and information about the RUs to be used when sending information about the neighboring APs to the communication device 100. In this case, the information instructing each neighboring AP to send information about its own devices is included in the trigger type subfield of the common information field, while the information about the RUs is included in the RU allocation of the user information field. Note that if a neighboring AP is detected to be non-compliant with 11be based on the information about the received beacon frame, it may not be necessary to send a trigger frame.

[0068] In step S506, communication device 100 determines whether a response frame has been received. Examples of information about neighboring APs included in the response frame include: received signal strength related to the trigger frame received by the neighboring AP, information about STAs that have established connections with the neighboring AP, and information indicating whether to participate in multi-AP communication. The channel to be used when communication device 100 receives the response frame from the neighboring AP is determined based on the beacon frame information about the neighboring AP received by communication device 100. The RU to be used when the neighboring AP sends a response frame can be allocated from one channel to each communication device, or from multiple channels. For example, if each neighboring AP sends information about the neighboring AP with a frequency bandwidth of 80 MHz, four channels with a bandwidth of 20 MHz are used. Communication devices 104 to 106 can use multiple RUs or RA-RUs from one of the four channels to be used in this case, or they can use RUs or RA-RUs from multiple different channels. The frequency bandwidth and number of channels to be used in this case are not limited to this example. A neighboring AP that does not participate in multi-AP communication does not necessarily send a response frame to communication device 100 in response to the trigger frame.

[0069] In step S506, if it is determined that the communication device 100 has received a response frame, then in step S509, the communication device 100 determines a slave AP from among the neighboring APs based on information sent from the neighboring APs. Examples of slave AP determination methods may include: selecting an AP with a higher radio field strength in the trigger frame received by a neighboring AP, and selecting an AP that has established connections with a larger number of STAs. However, the slave AP determination method is not limited to these examples. As a selection method, for example, neighboring APs determined to have a radio field strength indicated by the trigger frame signal strength 414 in the response frame sent to the communication device 100 and higher than a reference value may be preferentially selected. This reference value may be set by the user. If the reference value is not set by the user, the default setting held in the storage unit 201 is used. An upper limit on the number of slave APs may be predetermined, and it may not be necessary to set all neighboring APs as slave APs.

[0070] In step S506, if it is determined that the communication device 100 has not received a response frame, the process terminates. If it is determined that no response frame has been received, it may be because, for example, a neighboring AP may be a communication device that does not conform to the 11be standard, or a neighboring AP may conform to the 11be standard but has been determined not to participate in multi-AP communication, and the neighboring AP has not sent a response frame to the communication device 100.

[0071] In step S510, the communication device 100 sends a slave AP determination notification frame to the AP that has been determined as a slave AP, thereby providing notification that the AP has been determined as a slave AP. If the AP is not determined as a slave AP, a slave AP determination notification frame indicating that the AP has not been determined as a slave AP may be sent, or a slave AP determination notification frame indicating that the AP has not been determined as a slave AP may not be sent.

[0072] In step S504, if there are no two or more neighboring APs, i.e., if only one neighboring AP exists, then in step S507, communication device 100 sends a frame to that neighboring AP. Examples of such frames include management frames conforming to action frames, etc. Frames sent from communication device 100 to each neighboring AP include information indicating that information about the neighboring AP should be sent to communication device 100. If only one neighboring AP exists, there is no need to send and receive information about multiple communication devices in parallel, eliminating the need for trigger frames and OFDMA.

[0073] In step S508, the communication device 100 determines whether a response frame has been received. If a response frame has been received in step S508, then in step S509, the communication device 100 determines the slave AP from among the nearby APs based on the received information. The method for determining the slave AP is as described above.

[0074] In step S510, if it is determined that no response frame has been received, the process is terminated.

[0075] The following will refer to Figures 6 to 8 describe Figure 5 The flowchart shows a specific example of the process.

[0076] Figure 6 This is a sequence diagram illustrating that communication device 100 stores a newly specified trigger type subfield value to instruct communication devices 104 to 106 to send information about their own devices to communication device 100 and to determine the location of the AP based on this information. The trigger type subfield value in the trigger frame is set to "8", and the AID12 subfield value is set to "2045" or "2047", and the trigger frame is sent to communication devices 104 to 106, which are neighboring APs, thereby instructing communication devices 104 to 106 to send information about their own devices.

[0077] Communication device 100 receives beacon frames (M6011) sent from each of communication devices 104 to 106, thereby detecting the presence of nearby APs. If a beacon frame is received, the trigger type subfield value is set to "8", thereby generating a multi-AP group formation trigger frame and sending the multi-AP group formation trigger frame to communication devices 104 to 106 (M6012). In this exemplary embodiment, communication device 100 and communication devices 104 to 106 have not yet established a connection, so AID has not been assigned to communication devices 104 to 106. Therefore, when the AID12 subfield value is set to "2045" or "2047", communication devices 104 to 106 use the RU that can be used by communication devices that have not been assigned AID to send information about their own devices to communication device 100 (M6013).

[0078] The communication device 100 determines the AP (M6014) based on the information received about the communication devices 104 to 106. Figure 6 The sequence diagram shown illustrates the case where communication devices 104 and 105 are identified as slave APs. In M6015, a slave AP identification notification frame is sent to each of communication devices 104 and 105. Since communication device 106 is not identified as a slave AP, no slave AP notification is sent. After identifying a slave AP, communication device 100 can periodically send the same trigger frame to some or all of the slave APs, and communication device 100 can obtain up-to-date information about the slave APs.

[0079] Figure 7 The sequence diagram illustrates that communication device 100 and communication devices 104 to 106 have established a connection before initiating the process of determining from the AP, and that communication device 100 determines from the AP after an AID has been assigned to each of communication devices 104 to 106. Communication device 100 sets the trigger type subfield value to "8", stores the assigned AID value, and sends a trigger frame, thereby instructing communication devices 104 to 106 to send information about their own devices to communication device 100.

[0080] Communication devices 104 to 106 send an association request frame (M7011) to communication device 100. In response to the received association request frame, communication device 100 sends an association response frame (M7012). As a result, communication device 100 and communication devices 104 to 106 establish a connection.

[0081] If a beacon frame (M7013) is received, the trigger type subfield value is set to "8" to generate a multi-AP group formation trigger frame and send the multi-AP group formation trigger frame to communication devices 104 to 106 (M7014). In this exemplary embodiment, the reception of a beacon frame is used as a trigger to send the trigger frame, but the transmission of an associated response frame can also be used as a trigger to send the trigger frame.

[0082] The values ​​assigned to communication devices 104 to 106 that have established connections are stored in the AID12 subfield value of the AID field 312 included in the user information field. Multiple sets of user information 306 corresponding to the number of neighboring APs that have established connections with communication device 100 are included in the AID field 312. Communication devices 104 to 106 that have received the trigger frame send information about their own devices (M7015) to communication device 100.

[0083] Perform the above steps after confirming that you are using AP.

[0084] In this exemplary embodiment, since a connection has been established between communication device 100 and communication devices 104 to 106, the information to be sent from the AP to communication device 100 after determining the AP also includes dynamically changing information. For example, the location of the AP may change and the distance between communication device 100 and the AP may increase, making communication impossible, or the channel performance between the AP and the STA may change depending on the location of the STA connected to the AP. This dynamically changing information can be obtained based on beacon frame information sent from communication devices 104 to 106 and received by communication device 100.

[0085] Figure 8 The sequence diagram shows that the existing trigger type subfield value is set to instruct communication devices 104 to 106 to send information about their own devices, and communication device 100 determines the source from the AP based on this information. Communication device 100 sets the trigger type subfield value to "0" and the AID12 subfield value to "2047", thereby instructing communication devices 104 to 106 to send information about their own devices to communication device 100.

[0086] Communication device 100 receives beacon frames (M8011) from each of communication devices 104 to 106 to detect the presence of a nearby AP. If a beacon frame is received, communication devices 104 to 106 generate trigger frames instructing each other to send information about their own devices to communication device 100, and send these trigger frames to each of communication devices 104 to 106 (M8012). In the IEEE 802.11ax standard, a trigger type subfield value of "0" indicates a trigger frame used for uplink multi-user (UL MU) transmission. However, when the trigger type subfield value is "0" and the AID12 subfield value is "2047", communication devices 104 to 106 interpret this as instructing each other to send information about their own devices to communication device 100. Upon receiving the trigger frame, communication devices 104 to 106 use the RU specified by communication device 100 to send information about their own devices to communication device 100 (M8013).

[0087] Perform the above steps after confirming that you are using AP.

[0088] As described above, the communication device 100 according to this exemplary embodiment sends a trigger frame, which includes information instructing multiple neighboring APs to send information about their own devices to the communication device 100 and information about RUs assigned to the multiple neighboring APs. The communication device 100 uses OFDMA to receive information about response frames in response to the trigger frame in parallel. Therefore, compared to the case where the communication device 100 communicates with multiple neighboring APs one-to-one sequentially and receives information from multiple neighboring APs, the time required to receive the necessary information can be reduced.

[0089] Reducing the time required to receive information from multiple neighboring APs enables the communication device 100 to efficiently select APs and start multi-AP communication earlier.

[0090] Note that the recording medium containing the software program code used to implement the above functions can be provided to the system or apparatus, and the program code stored in the recording medium can be read and executed by a computer (CPU, MPU) in the system or apparatus. In this case, the program code read from the storage medium implements the functions of the exemplary embodiments described above, and the storage medium storing the program code constitutes the apparatus described above.

[0091] As a storage medium for providing program code, for example, floppy disks, hard disks, optical disks, magneto-optical disks, CD-ROMs, CD-Rs, magnetic tapes, non-volatile memory cards, ROMs, DVDs, etc. can be used.

[0092] The aforementioned functions can be achieved not only by executing program code read by the computer, but also by the operating system (OS) running on the computer performing some or all of the actual processing based on the instructions of the program code. OS stands for Operating System.

[0093] Furthermore, the program code read from the storage medium is written into memory included in a function expansion board inserted into the computer or a function expansion unit connected to the computer. The aforementioned functions can be implemented, in whole or in part, by the CPU included in the function expansion board or function expansion unit, based on instructions from the program code.

[0094] The present invention can also be implemented in a manner in which a program for implementing one or more functions according to the exemplary embodiments described above is provided to a system or apparatus via a network or storage medium, and one or more processors in the computer of the system or apparatus read and execute the program. The present invention can also be implemented using circuitry (e.g., an ASIC) for implementing one or more functions.

[0095] This invention is not limited to the exemplary embodiments described above, and various modifications and variations can be made without departing from the spirit and scope of the invention. Therefore, the claims are appended to disclose the scope of the invention.

[0096] This application claims priority to Japanese Patent Application No. 2020-089815, filed on May 22, 2020, the entire contents of which are incorporated herein by reference.

Claims

1. A communication device that operates as an access point (AP) in a communication network, the communication device comprising: A generation unit is configured to generate trigger frames conforming to the IEEE 802.11 standard series, the trigger frames including first information and second information, the first information indicating that the communication device requests one or more other communication devices configured to operate as access points in the communication network to send a response regarding whether to participate in multi-AP communication, and the second information indicating resource unit (RU) allocation of the one or more other communication devices. A transmitting unit is configured to transmit the trigger frame generated by the generating unit to a plurality of other communication devices configured to operate as an AP; as well as The receiving unit is configured to use Orthogonal Frequency Division Multiple Access (OFDMA) to receive in parallel response frames sent from the plurality of other communication devices in response to the trigger frame using the RU indicated by the second information, each of the response frames including information about whether to participate in multi-AP communication; as well as The determining unit is configured to determine, based on the information included in the received response frame, one or more other communication devices to participate in multi-AP communication. Specifically, when the communication device requests a response from a single other communication device configured to operate as an AP regarding whether to participate in multi-AP communication, the sending unit sends a frame that does not trigger OFDMA communication; when the communication device requests individual responses from multiple other communication devices configured to operate as APs, the sending unit sends a trigger frame that triggers OFDMA communication.

2. The communication device of claim 1, wherein, The trigger frame sent by the sending unit is configured to allocate RU without specifying identification information of other communication devices.

3. The communication device according to claim 1, wherein, The first information is included in the public information field of the trigger frame, and the second information indicating RU allocation is included in the user information field of the trigger frame.

4. The communication device according to claim 1, wherein, The trigger type of the trigger frame is indicated by 0 or 8.

5. The communication device according to claim 1, wherein, The second information indicating RU allocation is included in the Resource Unit (RU) allocation subfield of the User Information field in the trigger frame.

6. The communication device according to claim 1, wherein, The trigger frame generated by the generation unit also includes information in which 1) the AID of the Random Access Resource Unit (RA-RU) available to other communication devices that have not yet established a connection is indicated and 2) the frequency components are correlated with each other.

7. The communication device according to claim 1, wherein, The trigger frame generated by the generation unit includes information about the AID assigned when a connection has been established with other communication devices, as well as the RU allocation of other communication devices indicated by the AID.

8. The communication device according to claim 7, wherein, The AID information is included in the user information field of the trigger frame.

9. The communication device according to claim 7, wherein, The AID information is included in the AID subfield of the user information field.

10. The communication device according to claim 1, wherein, The communication device operates as an access point conforming to the IEEE 802.11 standard series.

11. The communication device according to claim 1, wherein, The one or more other communication devices each operate as access points conforming to the IEEE 802.11 standard family.

12. A communication device that operates as an access point (AP) in a communication network, the communication device comprising: A receiving unit is configured to receive trigger frames conforming to the IEEE 802.11 standard series from other communication devices configured to operate as APs. The trigger frames include first information and second information, the first information indicating that the other communication devices configured to operate as APs request the communication device to send a response regarding whether to participate in multi-AP communication, and the second information indicating the resource unit (RU) allocation of the communication device. as well as The transmitting unit, configured to use Orthogonal Frequency Division Multiple Access (OFDMA) and the RU indicated by the second information, transmits a response frame including information about the communication device as a response to the frame received by the receiving unit. The response frame includes information about whether the communication device participates in multi-AP communication. In the case where other communication devices respond to a single communication device configured as an AP requesting information about whether to participate in multi-AP communication, the receiving unit receives a frame that does not trigger OFDMA communication; in the case where other communication devices respond to each of the other communication devices configured as APs, the receiving unit receives a trigger frame that triggers OFDMA communication.

13. A communication method for communication between a first communication device and one or more second communication devices, the first communication device being configured to operate as an access point in a communication network, the one or more second communication devices being different from the first communication device, the communication method comprising: A trigger frame conforming to the IEEE 802.11 standard series is generated by a first communication device. The trigger frame includes first information and second information. The first information indicates that the first communication device requests one or more second communication devices configured to operate as access points to send a response regarding whether to participate in multi-AP communication. The second information indicates the allocation of resource units (RUs) of the one or more second communication devices. Send the generated trigger frame to the one or more second communication devices; In response to receiving the trigger frame, each of the plurality of second communication devices sends a response frame, as indicated by the second information, including information about its own device, the response frame including information about whether it participates in multi-AP communication; The response frame is received and transmitted in parallel by the first communication device using Orthogonal Frequency Division Multiple Access (OFDMA); as well as Based on the information included in the received response frame, a second communication device to participate in the multi-AP communication is determined. Specifically, when the first communication device requests a response from a single second communication device regarding whether to participate in multi-AP communication, the first communication device sends a frame that does not trigger OFDMA communication; when the first communication device requests responses from multiple second communication devices, the first communication device sends a trigger frame that triggers OFDMA communication.

14. A storage medium for a stored program, the program being used to enable a computer to function as a unit of the communication device according to claim 1.

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