Communication device, communication method, and program

Abstract

To suppress communication overhead associated with transmission of a trigger frame when performing Multi-Link communication.SOLUTION: When a communication device establishes connections with other communication devices via multiple links, the communication device instructs the other communication devices to send data, and transmits a frame that triggers the other communication devices to send data to the communication device, in which a pair of first and second fields in the frame is included for each established link.SELECTED DRAWING: Figure 8

Description

Technical Field

[0001] The present invention relates to a communication device and a communication method for performing wireless communication.

Background Art

[0002] With the increase in the amount of data to be communicated in recent years, the development of communication technologies such as wireless LAN (Local Area Network) has been promoted. As the main communication standards for wireless LAN, the IEEE (Institute of Electrical and Electronics Engineers) 802.11 standard series is known. The IEEE 802.11 standard series includes standards such as IEEE 802.11a / b / g / n / ac / ax. For example, in the latest standard IEEE 802.11ax, technologies for improving the communication speed under congested conditions in addition to a high peak throughput of up to 9.6 gigabits per second (Gbps) using OFDMA (Orthogonal Frequency-Division Multiple Access) have been standardized (see Patent Document 1). Note that OFDMA is an abbreviation for Orthogonal frequency-division multiple access.

[0003] [[ID=!5]] As a successor standard aiming at further throughput improvement, improvement in frequency utilization efficiency, and improvement in communication latency, a task group called IEEE 802.11be has been established.

[0004] In the IEEE 802.11be standard, Multi-Link communication in which one AP (Access Point) establishes a plurality of links with one STA (Station) via different multiple frequency channels and communicates in parallel is being studied.

[0005] Also, in IEEE 802.11ax, in order to control the uplink communication of the STA, the AP transmits a trigger frame to the STA that is the communication partner.

Prior Art Documents

Patent Documents

[0006] [Patent Document 1] Japanese Patent Publication No. 2018-50133 [Overview of the Initiative] [Problems that the invention aims to solve]

[0007] In the Multi-Link communication being considered under IEEE 802.11be, it is assumed that different parameters will be applied to the first and second links to perform communication.

[0008] However, for example, when sending a trigger frame while performing multi-link communication between the first and second links, conventional trigger frames could not send different parameters for each link. Therefore, if it was necessary to apply different parameters to the first and second links, it was necessary to send the trigger frame multiple times for each link, which could increase communication overhead.

[0009] In view of the above issues, the present invention aims to suppress the communication overhead associated with the transmission of trigger frames when performing Multi-Link communication. [Means for solving the problem]

[0010] To achieve the above objective, the communication device of the present invention includes establishing means for establishing connections with other communication devices via multiple links, each with a different channel, This indicates information identifying the first link among the plurality of links. First Link ID field included Regarding the first link First Link Info Field and A first User Info field including an AID12 field that indicates information identifying other communication devices that prompt transmission on the first link identified by the first Link ID field, and a RU Allocation field that indicates the allocation of resource units used by the other communication devices for transmission, This indicates information that identifies a second link, which is different from the first link described above. Second Link ID field included Regarding the second link Second Link Info Field and A second User Info field including an AID12 field that indicates information identifying other communication devices that prompt transmission in the second link identified by the second Link ID field, and a RU Allocation field that indicates the allocation of resource units used by the other communication devices for transmission,Transmission means for transmitting a trigger frame including the same to the first link, In the trigger frame, The 1 field is arranged after the first User Info field, Link Info The second Link Info field is arranged after the 1 field of User Info the The 2 field of User Info the Link Info is arranged after the second field.

Advantages of the Invention

[0011] According to the present invention, when performing Multi-Link communication, it is possible to suppress the communication overhead associated with the transmission of a trigger frame.

Brief Description of the Drawings

[0012] [Figure 1] It is a diagram showing the configuration of a network in the present invention. [Figure 2] It is a diagram showing the hardware configuration of a communication device in the present invention. [Figure 3] It is a diagram showing the functional configuration of a communication device in the present invention. [Figure 4] It is a sequence diagram when the communication device 103 transmits data to the communication device 102 in the present invention. [Figure 5] It is a flowchart showing the trigger frame transmission of the communication device 102 in the present invention. [Figure 6] It is a diagram showing an example of a trigger frame related to a BSR Request transmitted from the communication device 102 to the communication devices 103 and 104 in the present invention. [Figure 7] It is a diagram showing an example of an ACK frame transmitted from the communication device 102 to the communication devices 103 and 104 in the present invention. [Figure 8] FIG. 1 is a diagram showing an example of a trigger frame in Embodiment 1 transmitted from communication device 102 to communication devices 103 and 104 in the present invention. [Figure 9] FIG. 1 is a diagram showing an example of a trigger frame in Embodiment 1 transmitted from communication device 102 to communication devices 103 and 104 in the present invention. [Figure 10] FIG. 2 is a diagram showing an example of a trigger frame in Embodiment 2 transmitted from communication device 102 to communication devices 103 and 104 in the present invention. [Figure 11] FIG. 3 is a diagram showing an example of a trigger frame in Embodiment 3 transmitted from communication device 102 to communication devices 103 and 104 in the present invention.

Embodiments for Carrying Out the Invention

[0013] 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.

[0014] (Configuration of Wireless Communication System) FIG. 1 shows the configuration of a network in which an AP (Access Point) 102, a STA (Station) 103, and a STA 104 according to the present embodiment participate. The AP 102 is a communication device having a role of constructing the network 101. Here, the network 101 is a wireless network. Also, the STA (Station) 103 and 104 are communication devices having a role of participating in the network 101.

[0015] Each communication device complies with the IEEE 802.11be (EHT) standard and can perform wireless communication compliant with the IEEE 802.11be standard via network 101. IEEE stands for Institute of Electrical and Electronics Engineers. EHT stands for Extremely High Throughput. EHT may also be interpreted as an abbreviation for Extreme High Throughput. Each communication device can communicate in the 2.4GHz, 5GHz, and 6GHz frequency bands. The frequency band used by each communication device is not limited to these; different frequency bands, such as the 60GHz band, may be used. Furthermore, each communication device can communicate using bandwidths of 20MHz, 40MHz, 80MHz, 160MHz, and 320MHz.

[0016] AP102 and STA103 and STA104 can perform multi-user (MU) communication by multiplexing signals from multiple users by executing OFDMA communication compliant with the IEEE 802.11be standard. OFDMA stands for Orthogonal Frequency Division Multiple Access. In OFDMA communication, a portion of the divided frequency band (RU, Resource Unit) is allocated to each STA so as not to overlap, and the carrier waves allocated to each STA are orthogonal. Therefore, an AP can communicate with multiple STAs in parallel.

[0017] IEEE 802.11ax specifies the method for transferring data from an STA to an AP in OFDMA. First, the AP checks each STA to see if it has any data to send. The frame used for this check is called a BSR (Buffer Status Report) Request. In response, each STA informs the AP of the amount of data it plans to send. The information contained in this frame is called the BSR (Buffer Status Report). Note that this is just one example, and there are other ways to communicate the BSR to the AP. For example, the BSR may be included in the data frame or control frame that the STA sends to the AP. Based on the BSRs received from each STA, the AP assigns STAs to each subchannel and sends a frame that initiates data transmission. This initiating frame is called a Trigger frame. The Trigger frame contains information on which subchannel each STA should use to transmit data and the available time period. According to the information in the Trigger frame, the STAs send data to the AP. In this way, even in environments with many STAs and congestion, STAs can transmit data while avoiding collisions.

[0018] Furthermore, AP102 and STA103,104 perform Multi-Link communication, establishing multiple links and communicating via multiple different frequency channels. APs that perform Multi-Link communication are also called AP MLDs (Multi-Link Devices). Here, a frequency channel refers to a frequency channel defined in the IEEE 802.11 series standard that can perform wireless communication compliant with the IEEE 802.11 series standard. The IEEE 802.11 series standard defines multiple frequency channels in each frequency band: the 2.4GHz band, the 5GHz band, and the 6GHz band. The IEEE 802.11 series standard also defines the bandwidth of each frequency channel as 20MHz. However, by bonding with adjacent frequency channels, a bandwidth of 40MHz or more may be used in a single frequency channel. For example, AP102 can establish a first link 105 with STA103 via a first frequency channel in the 2.4GHz band, and a second link 106 via a second frequency channel in the 5GHz band, and communicate via both links. In this case, AP102 maintains a second link 106 via a second frequency channel in parallel with the first link 105 via a first frequency channel. In this way, AP102 can improve the throughput of communication with STA103 by establishing multiple links with STA103, each corresponding to a different frequency channel.

[0019] Furthermore, AP102 and STA103 may establish multiple links in different frequency bands in Multi-Link communication. For example, AP102 and STA103 may establish a first link 104 in the 2.4GHz band, a second link 105 in the 5GHz band, and a third link in the 6GHz band. Alternatively, links may be established via multiple different channels within the same frequency band. For example, a first link 105 may be established via channel 1 in the 2.4GHz band, and a second link 106 may be established via channel 5 in the 2.4GHz band. Furthermore, links with the same frequency band and links with different frequency bands may be mixed. For example, AP102 and STA103 may establish a first link 105 via channel 1 in the 2.4GHz band, a second link 106 via channel 5 in the 2.4GHz band, and a third link via channel 36 in the 5GHz band. AP102 can establish multiple connections with STA103 using different frequency bands, allowing it to communicate with STA103 on other bands even when one band is congested, thus preventing a decrease in throughput during communication with STA103.

[0020] In multi-link communication, the multiple links established by AP102 and STA103 only need to have at least different frequency channels. Furthermore, in multi-link communication, the channel spacing between the frequency channels of the multiple links established by AP102 and STA103 only needs to be at least greater than 20 MHz. In this embodiment, AP102 and STA103 are shown to establish a first link 105 and a second link 106, but three or more links may be established.

[0021] Furthermore, when performing Multi-Link communication, AP102 constructs multiple wireless networks corresponding to each link. In this case, AP102 internally has multiple APs and operates to construct a wireless network for each of them. The APs that AP102 internally has may be one or more physical APs, or they may be multiple virtual APs configured on a single physical AP. Furthermore, if multiple links are established on a frequency channel belonging to a common frequency band, a common wireless network may be used for these multiple links.

[0022] When performing multi-link communication, AP102 and STA103 and STA104 divide a single data file and transmit it to the other device via multiple links. Alternatively, AP102 and STA103 and STA104 may transmit the same data via each of the multiple links, so that communication via one link serves as a backup for communication via the other links. Specifically, AP102 may transmit the same data to STA103 via a first link via a first frequency channel and a second link via a second frequency channel. In this case, even if an error occurs in communication via the first link, STA103 can receive the data transmitted from AP102 because the same data is being transmitted via the second link. Alternatively, AP102 and STA103 may use different links depending on the type of frame or data being communicated. For example, AP102 may transmit management frames via the first link and data frames containing data via the second link. Specifically, management frames refer to Beacon frames, Probe Request frames / Response frames, and Association Request frames / Response frames. In addition to these frames, Disassociation frames, Authentication frames, De-Authentication frames, and Action frames are also called management frames. Beacon frames are frames that broadcast network information. Probe Request frames are frames that request network information, and Probe Response frames are the responses that provide network information. Association Request frames are frames that request a connection, and Association Response frames are the responses that indicate whether the connection is permitted or an error occurs. Disassociation frames are frames that disconnect a connection.An Authentication frame is used to authenticate the other device, while a De-Authentication frame interrupts the authentication of the other device and disconnects the connection. An Action frame is used to perform additional functions other than those described above. AP102 and STA103, 104 send and receive management frames compliant with the IEEE 802.11 series standard. Alternatively, when AP102 transmits data related to an captured image, for example, metadata such as the date, capture parameters (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.

[0023] Furthermore, AP102 and STA103, 104 may perform MIMO (Multiple-Input And Multiple-Output) communication. In this case, AP102 and STA103, 104 have multiple antennas, with each antenna sending different signals from the same frequency channel. The receiving side simultaneously receives all signals arriving from multiple streams using multiple antennas, separates the signals from each stream, and decodes them. By performing MIMO communication in this way, AP102 and STA103, 104 can communicate more data in the same amount of time compared to when MIMO communication is not performed. In addition, AP102 and STA103, 104 may perform MIMO communication on some links when performing Multi-Link communication.

[0024] While AP102 and STA103 / 104 are stated to be compatible with the IEEE 802.11be standard, they may also be compatible with at least one of the legacy standards preceding the IEEE 802.11be standard or the successor standard to IEEE 802.11be. Here, legacy standards refer to the IEEE 802.11a / b / g / n / ac / ax standards. In this embodiment, at least one of the IEEE 802.11a / b / g / n / ac / ax / be standards and their successor standards is referred to as the IEEE 802.11 series standard. In addition to the IEEE 802.11 series standard, they may also be compatible with other communication standards such as Bluetooth®, NFC, UWB, Zigbee, and MBOA. UWB stands for Ultra Wide Band, and MBOA stands for Multi Band OFDM Alliance. OFDM stands for Orthogonal Frequency Division Multiplexing. NFC stands for Near Field Communication. UWB includes wireless USB, wireless 1394, Winet, etc. It may also support wired communication standards such as wired LAN.

[0025] Specific examples of AP102 include, but are not limited to, wireless LAN routers and PCs. AP102 can be any communication device capable of performing Multi-Link communication with other communication devices. AP102 may also be an information processing device such as a wireless chip capable of performing wireless communication compliant with the IEEE 802.11be standard. Specific examples of STA103 and STA104 include, but are not limited to, cameras, tablets, smartphones, PCs, mobile phones, and video cameras. STA103 and STA104 can be any communication device capable of performing Multi-Link communication with other communication devices. STA103 and STA104 may also be information processing devices such as wireless chips capable of performing wireless communication compliant with the IEEE 802.11be standard. The network in Figure 1 consists of one AP and one STA, but the number of APs and STAs is not limited to this. Note that information processing devices such as wireless chips have antennas for transmitting the generated signals.

[0026] In this embodiment, AP102 is an access point and STA103 and 104 are stations, but this is not limited to this configuration; AP102 and STA103 and 104 may also be stations. In this case, AP102 is a station, but it operates as a device that has the role of building a wireless network to establish links with STA103 and 104.

[0027] (AP and STA configuration) Figure 2 shows an example of the hardware configuration of AP102 in this embodiment. STA103 and STA104 can have a similar configuration. AP102 includes a storage unit 201, a control unit 202, a function unit 203, an input unit 204, an output unit 205, a communication unit 206, and an antenna 207.

[0028] The memory unit 201 is composed of one or more memories such as ROM and RAM, and stores various information such as computer programs for performing various operations described later, and communication parameters for wireless communication. ROM stands for Read Only Memory, and RAM stands for Random Access Memory. In addition to memories such as ROM and RAM, the memory unit 201 may also use 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. Furthermore, the memory unit 201 may have multiple memories.

[0029] The control unit 202 is composed of one or more processors, such as a CPU and an MPU, and controls the entire AP102 by executing a computer program stored in the memory unit 201. Alternatively, the control unit 202 may control the entire AP102 in cooperation with the computer program stored in the memory unit 201 and the OS (Operating System). The control unit 202 also generates data and signals (wireless frames) to be transmitted in communication with other communication devices. Note that CPU stands for Central Processing Unit, and MPU stands for Micro Processing Unit. Furthermore, the control unit 202 may be equipped with multiple processors, such as a multi-core processor, and the entire AP102 may be controlled by these multiple processors.

[0030] Furthermore, the control unit 202 controls the functional unit 203 to perform predetermined processes such as wireless communication, imaging, printing, and projection. The functional unit 203 is the hardware that enables the AP100 to perform predetermined processes.

[0031] The input unit 204 receives various operations from the user. The output unit 205 provides various outputs to the user via a monitor screen or speaker. Here, the output from the output unit 205 may be a display on the monitor screen, audio output via speaker, vibration output, etc. Furthermore, both the input unit 204 and the output unit 205 may be implemented in a single module, such as a touch panel. In addition, the input unit 204 and the output unit 205 may be integrated with AP102 or may be separate components.

[0032] The communication unit 206 controls wireless communication compliant with the IEEE 802.11be standard. In addition to the IEEE 802.11be standard, the communication unit 206 may also control wireless communication compliant with other IEEE 802.11 series standards, as well as wired communication such as wired LAN. The communication unit 206 controls the antenna 207 to transmit and receive signals for wireless communication generated by the control unit 202. AP102 having multiple communication units 206 establishes at least one link per communication unit 206 when establishing multiple links in Multi-Link communication. Alternatively, AP102 may establish multiple links using a single communication unit 206. In this case, communication via multiple links is performed by switching the frequency channels on which the communication unit 206 operates in time division.

[0033] Furthermore, if AP102 supports NFC, Bluetooth, or other standards in addition to the IEEE 802.11be standard, it may control wireless communication compliant with these communication standards. Also, if AP102 can perform wireless communication compliant with multiple communication standards, it may be configured to have separate communication units and antennas corresponding to each communication standard. AP102 communicates data such as image data, document data, and video data with STA103 and 104 via the communication unit 206. The antenna 207 may be configured separately from the communication unit 206, or it may be configured as a single module together with the communication unit 206.

[0034] Antenna 207 is an antenna capable of communication in the 2.4GHz, 5GHz, and 6GHz bands. In this embodiment, AP102 is assumed to have one antenna, but it may have multiple antennas, or it may have different antennas for each frequency band. Furthermore, if AP102 has multiple antennas, it may have a communication unit 206 corresponding to each antenna.

[0035] Figure 3 shows a block diagram of the functional configuration of AP102 in this embodiment. Note that STA103 and STA104 can have a similar configuration. Here, AP100 is assumed to have three wireless LAN control units 301, 308, and 310. Note that the number of wireless LAN control units is not limited to three; it may be one, two, or four or more. AP100 further includes a frame generation unit 302, a frame analysis unit 303, a channel allocation unit 304, a UI control unit 305, a storage unit 306, and wireless antennas 307, 309, and 311.

[0036] The wireless LAN control units 301, 308, and 310 consist of antennas and circuits for sending and receiving wireless signals with other wireless LAN devices, and programs for controlling them. The wireless LAN control unit 301 performs wireless LAN communication control based on frames generated by the frame generation unit 302 in accordance with the IEEE 802.11 standard series.

[0037] The frame generation unit 302 generates wireless control frames to be transmitted by the wireless LAN control unit 301. In some cases, the frames generated here may also be transmitted by the wireless LAN control units 308 and 310. The content of the wireless control generated by the frame generation unit 302 may be restricted by settings stored in the storage unit 305. It may also be changed by user settings from the UI control unit 304.

[0038] The frame analysis unit 303 interprets the frames received by the wireless LAN control units 301, 308, and 310, and reflects their contents back into the wireless LAN control units 301, 308, and 310. Regardless of which control unit receives the frame, by passing it through the frame control unit 303, it becomes possible to control wireless LAN control units that have not received the frame.

[0039] The channel assignment unit 304 determines the appropriate channel for communication between the AP and STA when instructing communication with a communication partner or with an STA. According to the assignment determined here, for example, AP105 and STA107 communicate on the channel or a subchannel defined within it.

[0040] The UI control unit 305 includes hardware related to the user interface, such as a touch panel or buttons, for receiving operations on the AP by a user (not shown) of the AP, and a program to control them. The UI control unit 304 also has functions for presenting information to the user, such as displaying images or outputting audio.

[0041] The memory unit 306 is a storage device that may consist of ROM and RAM, etc., for storing the program and data on which the AP operates.

[0042] (Embodiment 1) In this embodiment, AP102 and STA103 communicate via Multi-Link. OFDMA is used as the communication method, and when STA103 transmits data to AP102, it starts transmission from a trigger frame received by AP102.

[0043] Figure 4 shows an example of a sequence diagram of the processing when AP102 receives data from STA103.

[0044] First, AP102 sends a BSR (Buffer Status Report) Request (S401) to each connected STA to determine the amount of data to be transmitted. While a BSR Request can be sent for each link, it is preferable to send it only for the representative link. By sending a BSR Request for only one link, the bandwidth of the unused links can be effectively utilized by other communication devices, and the power consumption of AP102 itself can be reduced.

[0045] Figure 6 shows an example of the frame format for a BSR Request sent via S401. Specifically, it uses Frame Control fields 601 to Common Info 605.

[0046] Table 1 shows the correspondence between the subfield values ​​stored in Trigger Type and the trigger types.

[0047] [Table 1]

[0048] The Trigger Type 609 of Common Info 605 is set to subfield value 4 as shown in Table 1 to indicate that it is a BSR Request. In a BSR Request, the value of the Length subfield 610 is 0, and there is no User Info field. This is followed by the Padding field 607 and the FCS field 608. Alternatively, the Length subfield may be used to specify the length of the subsequent subfields. In that case, a field indicating the channel number or link number requesting the BSR may be added after the Length subfield.

[0049] In S401, when STA103 receives a BSR Request from AP102, it transmits a BSR to AP102 (S402). While a BSR may be transmitted for each link, it is preferable to transmit it only on the designated link. In Figure 4, Link1 is designated as the designated link. Furthermore, it is preferable that the link on which the BSR is transmitted to AP102 is the same link that received the BSR Request. This is because AP102 is likely waiting to receive a BSR on the link that received the BSR Request. Additionally, transmitting frames only on the designated link allows other communication devices to effectively utilize the frequency channels used by links other than the designated link. This also reduces the power consumed by STA103 during transmission.

[0050] The BSR sent here may send the buffer size of the data to be sent waiting on each link, or it may send the total buffer size of the data to be sent waiting on all links. Furthermore, the BSR Request may include instructions on whether to return the total buffer size of the data to be sent for each link, or the buffer size for each link. For example, a BSR Policy subfield may be added after the Length subfield, where a value of 0 requests the buffer size for each link, and a value of 1 requests the buffer size of the data to be sent for all links.

[0051] Note that the BSR may be received by other means. For example, AP102 may receive and analyze the BSR value attached to data previously transmitted by STA103. The BSR is indicated in the QoS Control field of the MAC HEADER. Bits 0-3 of the QoS field indicate the TID of the data, and bits 8-15 indicate the Queue Size. The Queue Size includes the size of the data that STA plans to send to the AP. Note that the BSR may be indicated in other ways. For example, it may be indicated in HT Control. The HT Control field indicates that it is an IEEE802.11ax operational value by setting bits 0-1 to 1. This indicates that it is an IEEE802.11be operational value by setting bits 0-2 to 1, and we may proceed to the details of operational values ​​below.

[0052] The operation value is classified into a 4-bit Control ID and Control Information. When the 4-bit Control ID is 3, it indicates that the Control Information is BSR. When the Control ID is BSR, the Control Information consists of ACI Bitmap, Delta TID, ACI High, Scaling Factor, Queue Size High, and Queue Size All. Here, more detailed information about the buffer size of the transmitted data can be conveyed to the communication partner than is sent in the QoS Control field. For example, the ACI Bitmap subfield uses 4 bits and contains information about which TID contains data. Furthermore, the Scaling Factor field can indicate the scale of the Queue Size. The High Queue Size field indicates the Queue Size for the highest priority TID, and the Queue Size All field indicates the Queue Size when all TIDs are combined. A Link field can also be added to send the Queue Size for each link.

[0053] In S402, when AP102 receives a BSR from an STA, it assigns each STA to the appropriate RU based on the received BSR and transmits a trigger frame accordingly (S403).

[0054] Figure 8 shows an example of the frame format of a trigger frame transmitted by S403. In this frame, information about the link on which the STA transmits data is stored in the Link ID 812 of the Link Info field 805.

[0055] This includes Frame Control801, Duration802, RA803, TA804, Link Info805, User Info806, Padding807, and FCS808 from the beginning.

[0056] The 4-bit Trigger Type subfield 801 in the Link Info field 805 specifies the type of trigger caused by the trigger frame. The UL Length subfield 810 in the Link Info field 805 represents the communication period common to all STAs. This communication period corresponds to the amount of data that each STA can send and receive.

[0057] When the Trigger type subfield value shown in Table 1 is 8, the trigger frame indicates that in Multi-Link communication, it is a frame that instructs the STA, which has established a connection with the AP, to send the data it is holding to the AP.

[0058] The Link ID subfield 812, included in the Link Info field 805, contains information about the link on which the STA, which has established a connection with AP102, transmits data. For example, when instructing data transmission on the first link operating on channel 5 of the 2.4GHz band, the value of Link ID subfield 812 is set to 1. In this way, link information is stored in the Link ID subfield 812. The link number is assigned by AP102 when the AP and STA connect and is given to STA103. The Link ID subfield is provided with 3 bits. The number of bits provided is not limited to this. For example, the subfield may be 2 bits, 5 bits, or 8 bits. The value of this subfield may also be assigned to the channel number. For example, when instructing STA103 to transmit data to AP102 on channel 5 of 2.4GHz, the value may be set to 5. In this case, when channel information is used as the subfield value, 8 bits are provided for the subfield. The value provided here may also be a value associated with the bandwidth. For example, 2.4GHz could be 1, 5GHz could be 2, and 6GHz could be 3. In this case, if you are allocating at 2.4GHz, set the channel subfield to 1. In this case, you only need to provide 2 bits as the subfield.

[0059] The Number of Remaining Link Info subfield 813 contains the remaining number of Link Info and User Info field pairs. For example, if the value of Number of Remaining Link Info is 3, it indicates that there are three more Link Info and User Info pairs following that particular Link Info and User Info pair.

[0060] Furthermore, if the value of Number of Remaining Link Info is 0, it indicates that no Link Info and User Info pairs follow the User Info field. In this case, it indicates that a Padding field appears after the User Info field. Number of Remaining Link Info813 is provided with 8 bits. The number of bits provided is not limited to this. For example, the Number of Remaining Link Info813 subfield may be 2 bits or 5 bits.

[0061] Furthermore, the Link Info field 805 includes information such as CS (Carrier Sense) Required, UL (Up Link) BW (Band Width), and AP Tx (Transmit) Power. Here, CS Required indicates whether carrier sensing by the STA is required, UL BW indicates the bandwidth of the channel used when the STA transmits data to the AP, and AP Tx Power indicates the transmit power of the AP that sends the trigger frame. By providing a Link Info field 805 for each established link, the AP can, for example, specify whether or not carrier sensing is required for each link, or specify the bandwidth for each link.

[0062] Furthermore, the information contained in Link Info 805 as described above is not limited to the information contained in the Common Info of the trigger frame as defined in IEEE 802.11ax. In other words, it is sufficient if at least one of the pieces of information contained in the Common Info of the trigger frame as defined in IEEE 802.11ax is included in Link Info field 805.

[0063] The User Info field 806 corresponds to each STA that establishes a connection with the AP, and pairs of Link Info field 805 and User Info field 806 are concatenated and transmitted for each STA that establishes a connection.

[0064] The User Info field 806 includes identifiers such as AID (Association ID) 12 and RU Allocation 313. AID 12 is represented by 12 bits. When the AID, which is the identification information assigned when the connection is established, is stored in AID 12, the lower 12 bits of the AID are stored. Therefore, in Table 2, subfields of AID 12 are explicitly labeled as AID 12 subfields.

[0065] The User Info field 806 contains the AID12 subfield 814, and Table 2 shows the correspondence between the value of the AID12 subfield 814 and its meaning.

[0066] [Table 2]

[0067] If the AID12 subfield contains a value between 1 and 2007, it indicates that the User Info is for an STA whose AID assigned when the connection was established matches the value in the AID12 subfield. If the AID12 subfield contains 2045, it indicates that the User Info is for an STA whose connection has not been established and which has not been assigned an AID.

[0068] In this embodiment, the value of the AID12 subfield is the value assigned by AP102 to STA103, for example, 1.

[0069] The RU Allocation subfield 815 identifies the RU and tone size of the corresponding STA. The RU Allocation subfield is provided with 8 bits.

[0070] The RU Allocation subfield 815 is used to allocate RUs, which are frequency components used by STA103 when transmitting data to AP102. Table 3 shows examples of RU values ​​to assign to the RU Allocation subfield.

[0071] The combination of the Link ID subfield 812 and the paired RU Allocation subfield 815 allows STA103 to determine the channel frequency for transmitting data to AP102.

[0072] [Table 3]

[0073] For example, if the frequency channel used is 20MHz and the value of the RU Allocation subfield is 38, the tone size of the subchannels is allocated at 52, and the second RU will be allocated to STA103. Multiple RUs can also be assigned to the same STA. When assigning multiple RUs to the same STA, different Link ID subfields or different RU Allocation subfields are assigned with the same AID. Alternatively, different RU Allocation subfields with the same Link ID subfield are assigned with the same AID. In this case, a User Info field 806 will be prepared for each assigned RU. A different representation is also possible for assigning multiple RUs to a single STA. For example, a 1-bit Cascaded subfield can be added after the AID subfield. If this bit is set, the RU Allocation subfield 815 is followed by another Cascaded subfield, the Link ID subfield, and the RU Allocation subfield. If this bit is 0, the next subfield follows. This assignment method allows for the allocation of multiple channels with fewer bits. Furthermore, RUs can be flexibly allocated even when the bandwidth differs for each channel.

[0074] However, this is just one example, and other representation methods are also possible. In this embodiment, since the channel is also represented, the bandwidth used may be limited to 20MHz units. In this case, the RU Allocation subfield only needs to be 4 bits. Alternatively, a Cascaded subfield may be provided to limit it to 20MHz.

[0075] The frame format in Figure 8 is just an example, and the specification of Link ID and RU is not limited to this. For example, RUs may be assigned in ascending order of Link number. In this case, for example, if there is a bandwidth of 40MHz each for 1 channel at 2.4GHz and 36 channels at 5GHz, and if the RU size is to be assigned only to 26, the RUs would be assigned as follows: RUs 1-18 used for 1 channel at 2.4GHz would be assigned 0-17. RUs 19-37 used for 36 channels at 5GHz would be assigned 18-36.

[0076] Furthermore, the Link Info field of the trigger frame may be defined as shown in Figure 9. Here, the Number of User Info field 914 indicates the number of User Info fields corresponding to that Link Info field. The other fields of the trigger frame are the same as the frame format shown in Figure 8. By adding the Number of User Info field 914, one or more User Info fields following the Link Info field can refer to the parameters indicated in the Link Info field.

[0077] In DL / UL subfield 614, the following data specifies whether the STA is sending or receiving. For example, a value of 0 indicates transmission from the STA to the AP, and a value of 1 indicates transmission from the AP to the STA.

[0078] Furthermore, the names of the fields in the trigger frame are not limited to those listed above; different names may be used. Also, while the Link Info field is used to notify link-specific parameter information, it is not limited to this; it may also be included in trigger frame fields compliant with IEEE 802.11ax. For example, information equivalent to that in the Link Info field may be included in the Common Info field. Additionally, the order of the subfields is not limited to those listed above; different orders may be used.

[0079] In S403, when each STA receives the trigger frame transmitted by AP102, it transmits data to AP102 according to its assignment (S404, S405, S406).

[0080] When AP102 receives data transmitted by STA103, it sends an ACK (Acknowledgement) associated with that data as a response (S407). At this time, the ACK is sent as a single ACK for all received links, rather than one ACK for each link. An example of the frame format of the ACK sent at this time is shown in Figure 7. In this embodiment, a Block ACK (BA) is used as the ACK. This frame can send acknowledgments for multiple data items at once.

[0081] The fields / subfields shown here conform to the format specified in IEEE 802.11ax.

[0082] This includes Frame Control701, Duration702, RA703, TA704, BA Control705, BA Information706, and FCS707, starting from the beginning.

[0083] The BA Control field 705 includes the BA Ack Policy subfield 708, the Multi-TID subfield 709, the Compressed Bitmap subfield 710, and the GCR subfield 711.

[0084] The type of BA is specified by the combination of values ​​in the Multi-TID subfield 709, the Compressed Bitmap subfield 710, and the GCR (Groupcast with retries) subfield 711. Table 4 shows an example of the correspondence between each subfield and the type of BA.

[0085] [Table 4]

[0086] When the Multi-TID subfield value is 0, the Compressed Bitmap subfield value is 0, and the GCR subfield value is 0, BA ACK indicates that it is a Basic Ack.

[0087] Furthermore, a dedicated type of BA may be established. For example, a BA for Multi-Link may be defined when the Multi-TID subfield value is 0, the Compressed Bitmap subfield value is 0, and the GCR subfield value is 1.

[0088] The structure of the BA Information field differs depending on the type of BA. In the case of Basic, it includes the Block Ack Starting Sequence Control subfield 712 and the Block Ack Bitmap subfield 713.

[0089] The subfield 712 contains the Cascaded subfield 714, the Link ID subfield 715, and the Starting Sequence Number subfield 716. If the value of the Cascaded subfield 714 is 1, it means that the BA Information field continues. If it is 0, it is the last BA Information field. The Link ID subfield 715 specifies the Link number value designated by AP102. For example, if the Link number is 1, the value is set to 1. The Starting Sequence Number subfield 716 indicates the sequence number that will be started in the following Block Ack Bitmap subfield 713. The Block Ack Bitmap subfield 713 indicates which data frame has been received. If the third data from the sequence number indicated by Starting Sequence Number has been received, the value of the third bit is set to 1. Bits corresponding to sequence numbers that have not been received are set to 0.

[0090] In this way, in data communication initiated by a trigger frame, even in multi-link communication, the trigger frame and acknowledgment can be transmitted together on a single link.

[0091] Figure 5 is a flowchart showing the processing flow that occurs when AP102 performs Multi-Link communication with STA103 and transmits a trigger frame, and the control unit 202 executes a program stored in the memory unit 201 of AP102.

[0092] This flowchart begins when AP102 and STA103 establish a connection.

[0093] First, AP102 and STA103 establish a connection via multiple links (S501).

[0094] In S501, once AP102 and STA103 establish a connection via multiple links, the communication status related to the multi-link connection and the settings of each STA are checked (S502). S502 may also be performed when the connection process is completed in S501. Parameters to be checked for each STA include the Min-Max communication rate, communication bandwidth, communication channel, MCS, and whether simultaneous transmission and reception are possible. This allows AP102 to understand how much data it can expect to receive when allocating RUs to STA103.

[0095] In S502, after checking the communication status of the Multi-Link connection and the settings of each STA, AP102 sends a BSR Request (S503) to determine the amount of data transmitted by each connected STA. This corresponds to S401 in Figure 4.

[0096] AP102 receives a BSR (Blocked Service Response) in response to the BSR Request sent to STA103 in S503 (S504). STA103 sends a BSR to AP102 if it has data to send to AP102. It may also send a BSR even if it has no data to send.

[0097] AP102 determines whether simultaneous data transmission and reception are necessary based on the settings of each STA confirmed in S502 and the amount of data that the STA is waiting to transmit (S505). For example, if the channels of the links on which the STA connects to the AP are close together, or if the STA cannot simultaneously transmit data on one link and receive data on the other, AP102 instructs simultaneous data upload. Also, if the communication channels used by multiple links are 2.4GHz channels 1 and 3, if the communication periods are out of sync, they will interfere with each other and communication will not work properly, so communication using trigger frames is necessary. Alternatively, if the content of the data is shared across multiple links, synchronization is necessary for data transmission, and one way to synchronize the data is to use trigger frames. If the content of the data is shared across multiple links, for example, the data sequence number may be shared across multiple links. When transmitting a sequence number using a value common to multiple links, it is necessary to understand the context of the data when integrating the data. Sending and receiving trigger frames is used as the criterion for this. The system uses a unit of time from one trigger frame to the next, integrates the data within that unit, sorts it by sequence number, and identifies which data has been received and which has not.

[0098] In S505, if simultaneous operation is determined to be necessary, AP102 allocates RUs (Rules) to the connected STAs to be used when sending data to AP102 (S510). The allocation method is such that the STAs are evenly divided by the RUs they are assigned. For example, if STA103 and STA104 are connected to AP102, 106 RUs may be allocated to STA103 and STA104, respectively, so that the RU sizes are equal. Alternatively, RUs may be allocated according to the ratio of the upload data acquired by BSR. For example, if STA103 has 20 upload data and STA104 has 10 upload data, 106 RUs may be allocated to STA103 and 52 to STA104. The information of the RUs allocated to the STAs in S510 is stored in the RU Allocation subfield of the frame format.

[0099] In S510, once the assignment of a RU to the STA that sends the trigger frame is determined, the content of the trigger frame to be sent is determined based on the STA's information (S511). Specifically, for each link to be transmitted, the content of the Link Info field and User Info field is determined based on the information obtained in S502 and S504.

[0100] In this embodiment, the parameters of each link are specified in the trigger frame using a combination of the Link Info field and the User Info field, but the method of specifying parameters is not limited to this.

[0101] When sending a trigger frame (hereinafter referred to as a unified trigger frame) that summarizes the information of RUs assigned to multiple links, the unified trigger frame is sent according to the RU to which it was assigned (S512). This corresponds to 403 in Figure 4. An example of the trigger frame sent in S512 is shown in Figure 8. Based on the unified trigger frame sent in S512, data sent from each STA is received (S513).

[0102] In S513, when AP102 receives data from STA103, it sends an ACK (S514) to indicate that the data has been received. At this time, a single ACK is sent for data received from multiple links. The ACK sent in S514 corresponds to S407 in Figure 4. Once the ACK is sent in S514, this flowchart ends.

[0103] In S505, if it is determined that simultaneous operation is not required, the AP102 enters a data transmission / reception flow for each link and determines the STA to send the trigger frame (S506). At this time, the STA to be assigned may be determined independently for each link channel used, or an STA that transmits across multiple links may be assigned. For example, consider a case where STA103 is connected on 2.4GHz channel 5 and 5GHz channel 36, and STA104 is connected on 5GHz channel 36. In this situation, if STAs are assigned independently for each channel, for example, on channel 36, STA103 is assigned an RU size of 106 and STA104 is assigned an RU size of 106. Then, on channel 5, STA103 is assigned an RU size of 242. Furthermore, consider the case where STAs are assigned across multiple links. In this case, STA103 is assigned an RU size of 242 on channel 36. STA104 is assigned an RU size of 242 on channel 5. If data transmission and reception are managed on a per-link basis, meaning that STAs are allocated independently to each link channel, there is no need to synchronize across links. Therefore, faster links do not have to wait for slower links, allowing for faster data transmission and reception.

[0104] In S506, once the allocation of STAs on each link is determined, a trigger frame is sent on each link (S507). In S507, a Basic trigger frame compliant with IEEE 802.11ax is used. That is, 0 is stored in the Trigger Type field in the frame format shown in Figure 6, as described in Table 1.

[0105] Based on the trigger frame, it is determined whether or not data has been received from the STA (S508). If it is determined in S508 that data has been received, an ACK associated with the received data is sent (S509). In S509, an ACK is sent based on the data received on each link. The ACK sent at this time conforms to the ACK specified in IEEE 802.11. Alternatively, a common Block Ack may be sent across multiple links as described in S514. Once data reception is complete, the process is terminated.

[0106] According to this embodiment, when data is transmitted between AP102 and STA103 via multiple links, the trigger frame transmitted for each link can store information for each link, specifying which link STA should use to transmit data to AP. Therefore, since appropriate parameters can be specified for each link in the trigger frame, it becomes unnecessary to transmit the trigger frame multiple times, thereby reducing communication overhead.

[0107] (Embodiment 2) Embodiment 1 shows an example in which the STA sends a trigger frame in which information specifying the link for sending data to the AP is stored in the Link Info field.

[0108] In this embodiment, an example is shown in which the trigger frame shown in Figure 10 is used to store information in the User Info field that specifies a link for the STA to send data to the AP.

[0109] In the frame format shown in Figure 10, the Link Info subfield 1016 and the Number of Remaining Link Info subfield 1017 are included in the User Info field 806.

[0110] The Link ID subfield 1016 of the User Info field 806 contains information about the link to which STA103 transmits data when establishing a connection with AP102. For example, to instruct data transmission on the first link operating on channel 5 of the 2.4GHz band, the value of Link ID subfield 1016 should be set to 1. The link number is assigned by AP102 and assigned to STA103 when AP102 and STA103 connect. The Link ID subfield is provided with 3 bits. The number of bits is not limited to this. For example, the subfield may be 2 bits, 5 bits, or 8 bits. The parameters of the link specified in this Link ID subfield refer to the contents of the preceding Link Info field.

[0111] Furthermore, the Number of Remaining Link Info subfield 1017 contains the remaining number of Link Info field and User Info field pairs included in the User Info field 1006 and subsequent fields. For example, if the value of Number of Remaining Link Info is 3, it indicates that three Link Info field and User Info field pairs follow the current Link Info field and User Info field. The Number of Remaining Link Info field is provided with 8 bits. However, the number of bits is not limited to this. For example, the Number of Remaining Link Info subfield may be 2 bits or 5 bits.

[0112] The other trigger frame fields are similar to the frame format shown in Figure 8.

[0113] The trigger frame transmission sequence, data transmission / reception sequence, and flowchart are the same as in Embodiment 1 and are therefore omitted.

[0114] According to this embodiment, when data is transmitted between AP102 and STA103 via multiple links, the trigger frame transmitted for each link can store information for each link, specifying which link STA should use to transmit data to AP. Therefore, since appropriate parameters can be specified for each link in the trigger frame, it becomes unnecessary to transmit the trigger frame multiple times, thereby reducing communication overhead.

[0115] (Embodiment 3) Embodiments 1 and 2 show examples in which the STA stores information specifying the link for sending data to the AP in either the Link Info field or the User Info field, and then sends a trigger frame.

[0116] In this embodiment, the Link Info field and User Info field store distributed information specifying the link for which the STA sends data to the AP.

[0117] Figure 11 shows an example of the frame format in this embodiment.

[0118] This frame format includes a Link Info field 805 containing a Number of Remaining Link Info subfield 1117, and a User Info field 806 containing a Link ID field 1116.

[0119] The "Number of Remaining Link Info" subfield 1117 contains the remaining number of Link Info field and User Info field pairs included in the trigger frame, starting from User Info field 806.

[0120] Furthermore, the Link ID subfield 1115 in the User Info field 1106 contains information about the link to which the connected STA transmits data. For example, if data transmission is instructed on the first link operating on channel 5 of the 2.4GHz band, the value of this subfield is set to 1.

[0121] The other trigger frame fields are similar to the frame format shown in Figure 8.

[0122] The trigger frame transmission sequence, data transmission / reception sequence, and flowchart are the same as in Embodiment 1 and are therefore omitted.

[0123] According to this embodiment, when data is transmitted between AP102 and STA103 via multiple links, the trigger frame transmitted for each link can store information for each link, specifying which link STA should use to transmit data to AP. Therefore, since appropriate parameters can be specified for each link in the trigger frame, it becomes unnecessary to transmit the trigger frame multiple times, thereby reducing communication overhead.

[0124] Additionally, the Link Info field may include a Link ID field, and the User Info field may include a Number of Remaining Link Info field. The field names are not limited to those mentioned above; different names may be used.

[0125] Furthermore, while link-specific parameter information is currently communicated using the Link Info field, this is not the only option; it can also be included in a trigger frame compliant with IEEE 802.11ax. For example, information equivalent to that in the Link Info field can be included in the Common Info field.

[0126] Alternatively, a recording medium containing program code for software that implements the above-described functions may be supplied to a system or device, and the computer (CPU, MPU) of the system or device may read and execute the program code stored on the recording medium. In this case, the program code read from the storage medium itself will implement the functions of the above-described embodiment, and the storage medium containing that program code will constitute the above-described device.

[0127] For storing program code, storage media such as flexible disks, hard disks, optical disks, magneto-optical disks, CD-ROMs, CD-Rs, magnetic tapes, non-volatile memory cards, ROMs, and DVDs can be used.

[0128] Furthermore, the above-mentioned functions may be realized not only by the computer executing the program code it reads, but also by the operating system (OS) running on the computer performing some or all of the actual processing based on the instructions of that program code. OS stands for Operating System.

[0129] Furthermore, the program code read from the storage medium is written to the memory of a function expansion board inserted into the computer or a function expansion unit connected to the computer. Then, based on the instructions of that program code, the CPU of the function expansion board or function expansion unit may perform some or all of the actual processing to realize the above-mentioned functions.

[0130] The present invention can also be realized by supplying a program that implements one or more of the functions of the above-described embodiments to a system or device via a network or storage medium, and by having one or more processors in the computer of that system or device read and execute the program. It can also be realized by a circuit (e.g., an ASIC) that implements one or more functions. [Explanation of symbols]

[0131] 201 Storage section 202 Control Unit 203 Functional Section 204 Input section 205 Output section 206 Communications Department 207 Antenna

Claims

1. A communication device, A means for establishing connections with other communication devices via multiple links with different channels, A transmission means for transmitting a trigger frame on the first link, comprising: a first Link Info field for the first link, which includes a first Link ID field indicating information identifying the first link among the plurality of links; a first User Info field, which includes an AID12 field indicating information identifying another communication device that prompts transmission on the first link identified by the first Link ID field, and a RU Allocation field indicating the allocation of resource units used by the other communication device for transmission; a second Link Info field for the second link, which includes a second Link ID field indicating information identifying the second link different from the first link; and a second User Info field, which includes an AID12 field indicating information identifying another communication device that prompts transmission on the second link identified by the second Link ID field, and a RU Allocation field indicating the allocation of resource units used by the other communication device for transmission; In the trigger frame, The first User Info field is placed after the first Link Info field. The second Link Info field is placed after the first User Info field. The second User Info field is placed after the second Link Info field. A communication device characterized by the following features.

2. The system further includes a receiving means for receiving data transmitted by the other communication device as a response to the trigger frame transmitted by the transmitting means, The communication device according to claim 1, characterized in that, when the communication device receives first data on the first link and second data on the second link from the other communication device by the receiving means, it transmits an Ack (Acknowledgment) frame containing information indicating that the first data has been received and information indicating that the second data has been received over either the first link or the second link.

3. The communication device according to claim 2, characterized in that the Ack frame is a BlockAck frame compliant with the IEEE 802.11 standard series.

4. The communication device according to claims 1 to 3, characterized in that the trigger frame is a trigger frame conforming to the IEEE 802.11 standard series.

5. The communication device according to any one of claims 1 to 4, characterized in that the communication device operates as an AP (AccessPoint) compliant with the IEEE 802.11 standard series.

6. A communication method for communication devices, A connection establishment process for establishing connections with other communication devices via multiple links with different channels, A transmission step of transmitting a trigger frame on the first link, the trigger frame comprising: a first Link Info field for the first link including a first Link ID field indicating information identifying the first link among the plurality of links; a first User Info field including an AID12 field indicating information identifying another communication device that prompts transmission on the first link identified by the first Link ID field and an RU Allocation field indicating the allocation of resource units used by the other communication device for transmission; a second Link Info field for the second link including a second Link ID field indicating information identifying a second link different from the first link; and a second User Info field including an AID12 field indicating information identifying another communication device that prompts transmission on the second link identified by the second Link ID field and an RU Allocation field indicating the allocation of resource units used by the other communication device for transmission; In the trigger frame, The first User Info field is placed after the first Link Info field. The second Link Info field is placed after the first User Info field. The second User Info field is placed after the second Link Info field. A communication method for a communication device characterized by the following features.

7. A program for causing a computer to function as one of the means of a wireless communication device described in any one of claims 1 to 5.

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