Communication device, communication method, and program

Abstract

To allow communication devices to efficiently share information on whether a channel pair during multi-link communication can be simultaneously transmitted and received, and allow the devices to execute efficient multi-link communication.SOLUTION: A communication device has: communication means that can execute in parallel wireless frame communication using a first frequency channel and wireless frame communication using a second frequency channel; and transmission means that transmits, to the other communication device, information that indicates the distance on a frequency axis between the first frequency channel and the second frequency channel, the information indicating a channel distance required for executing in parallel wireless frame transmission using the first frequency channel and wireless frame reception using the second frequency channel in the communication performed by the communication means.SELECTED DRAWING: Figure 6

Description

Technical Field

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[0001] The present invention relates to wireless communication technology.

Background Art

[0002] With the increase in the amount of data communicated in recent years, the development of communication technologies such as wireless LAN (Local Area Network) has been advanced. 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 IEEE 802.11ax standard, technologies for improving the communication speed in congested situations 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] As a successor standard aiming for further throughput improvement, improvement in frequency utilization efficiency, and improvement in communication latency, the standardization of the IEEE 802.11be standard is underway.

[0004] In IEEE 802.11be, Multi-Link communication is being considered, in which one access point (AP) constructs a plurality of Links with one station (STA) in frequency bands such as the 2.4 GHz, 5 GHz, and 6 GHz bands and performs simultaneous communication. Also, due to hardware constraints of wireless communication devices and the like, in Multi-Link communication, processing for an AP or STA that cannot perform a reception operation on the other Link during a transmission operation on a predetermined Link is being considered.

Prior Art Documents

[0006] To implement efficient multi-link communication, it is necessary for the communicating devices to share information indicating which links can transmit and receive data simultaneously with other links. This is because using a pair of links that cannot send or receive simultaneously would require exclusive execution of the transmission and reception processes, reducing communication efficiency. However, conventionally, there has been no established method for sharing information between devices to indicate which links can send and receive simultaneously with other links, or how that information should be shared.

[0007] Therefore, the present invention aims to enable efficient Multi-Link communication between communication devices by allowing them to efficiently share information on whether simultaneous transmission and reception of channel pairs during Multi-Link communication is possible. [Means for solving the problem]

[0008] To achieve the above objective, the present invention is a communication device compliant with the IEEE 802.11 series standard that can perform Multi-Link communication with other communication devices via a first link using a first frequency and a second link using a second frequency different from the first frequency, and has a transmitting means that transmits first information relating to the difference between the first frequency and the second frequency necessary for performing STR (simultaneous transmit and receive) communication to the other communication device, and the difference between the first frequency and the second frequency is shown by multiplying a predetermined bandwidth and the first information. Furthermore, in order to achieve the above objective, the present invention is a communication device compliant with the IEEE 802.11 series standard that can perform Multi-Link communication with other communication devices by a first link using a first frequency and a second link using a second frequency different from the first frequency, and has receiving means for receiving first information relating to the difference between the first frequency and the second frequency necessary for performing STR (simultaneous transmit and receive) communication from the other communication device, and the difference between the first frequency and the second frequency is shown by multiplying a predetermined bandwidth and the first information. [Effects of the Invention]

[0009] According to the present invention, it becomes possible to efficiently share information between communication devices regarding whether simultaneous transmission and reception of channel pairs during Multi-Link communication is possible, thereby enabling efficient Multi-Link communication between devices. [Brief explanation of the drawing]

[0010] [Figure 1] This figure shows the network configuration according to the present invention. [Figure 2] This figure shows the hardware configuration of the communication device according to the present invention. [Figure 3] This is a block diagram showing the functional configuration of the communication device according to the present invention. [Figure 4] This is a sequence diagram showing how the channel distance of a STRable Link is notified in the Association Response for the Association candidate channel in Example 1. [Figure 5] This is an example of the configuration of the Association Response frame that AP101 sends to STA102 in Example 1. [Figure 6] This is a flowchart for determining the STR-possible channel distance for 20MHz transmission on the AP101. [Figure 7] This flowchart shows how to determine whether the channel A and channel B pair of AP101 can be STR'd when transmitting at 20MHz in Example 1. [Figure 8] In Example 2, AP101 detects transmission noise during 20MHz transmission for the channel A and channel B pair in advance of communicating with STA102. This flowchart illustrates the process. [Figure 9] This is a flowchart for determining whether the channel A and channel B pair of AP101 can be STR'd when transmitting at 20MHz in Example 2. [Modes for carrying out the invention]

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

[0012] (Configuration of the wireless communication system) Figure 1 shows the network configuration in which the communication device 102 (hereinafter referred to as STA102) according to this embodiment participates. STA102 is a station (STA) that has the role of participating in network 100. Communication device 101 (hereinafter referred to as AP101) is an access point (AP) that has the role of constructing the wireless network 100. AP101 can communicate with STA102.

[0013] Each of the AP101 and STA102 can perform wireless communication compliant with the IEEE 802.11be (EHT) standard. IEEE stands for Institute of Electrical and Electronics Engineers. The AP101 and STA102 can communicate in the 2.4 Hz, 5 GHz, and / or 6 GHz frequency bands. The frequency band used by each communication device is not limited to these, and different frequency bands, such as the 60 GHz band, may be used. Furthermore, the AP101 and STA102 can communicate using bandwidths of 20 MHz, 40 MHz, 80 MHz, 160 MHz, and 320 MHz. The bandwidth used by each communication device is not limited to these, and different bandwidths, such as 240 MHz and 4 MHz, may be used.

[0014] AP101 and STA102 can achieve multi-user (MU) communication by multiplexing signals from multiple users by performing 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 of each STA are orthogonal. Therefore, an AP can communicate in parallel with multiple STAs within a defined bandwidth.

[0015] Although AP101 and STA102 are assumed to comply with the IEEE802.11be standard, in addition to this, they may also comply with legacy standards that are older than the IEEE802.11be standard. Specifically, AP101 and STA102 may comply with at least one of the IEEE802.11a / b / g / n / ac / ax standards. Also, in addition to the IEEE802.11 series of standards, they may comply with other communication standards such as Bluetooth (registered trademark), NFC, UWB, ZigBee, MBOA, etc. Note that UWB is the abbreviation for Ultra Wide Band, MBOA is the abbreviation for Multi Band OFDM Alliance, and NFC is the abbreviation for Near Field Communication. UWB includes wireless USB, wireless 1394, WiNET, etc. Also, they may comply with the communication standards of wired communication such as wired LAN. Specific examples of AP101 include, but are not limited to, wireless LAN routers, personal computers (PCs), smartphones, etc. Also, AP101 may be an information processing device such as a wireless chip that can execute wireless communication compliant with the IEEE802.11be standard. Also, specific examples of STA102 include, but are not limited to, cameras, tablets, smartphones, PCs, mobile phones, video cameras, headsets, etc. Also, STA102 may be an information processing device such as a wireless chip that can execute wireless communication compliant with the IEEE802.11be standard. Each communication device can communicate using bandwidths of 20MHz, 40MHz, 80MHz, 160MHz, and 320MHz.

[0016] Furthermore, in this embodiment, AP101 and STA102 establish links via multiple frequency channels and perform Multi-Link communication. In the IEEE 802.11 series standard, the bandwidth of each channel is defined as 20 MHz. Here, a channel refers to a frequency channel as defined in the IEEE 802.11 series standard, which defines multiple channels in each frequency band: 2.4 GHz, 5 GHz, 6 GHz, and 60 GHz. Note that by coupling or bonding with adjacent channels, a bandwidth of 40 MHz or more may be used in a single channel. For example, AP101 can establish a link with STA102 via a first channel in the 2.4 GHz band and communicate. In parallel with this, STA102 can establish a link with AP101 via a second channel in the 5 GHz band and communicate. In this case, STA102 performs Multi-Link communication using Link 103 and Link 104 by maintaining the second link via the second channel in parallel with the link via the first channel. In this way, AP101 can improve the throughput of communication with STA102 by establishing a link with STA102 via multiple channels.

[0017] In addition, in Multi-link communication, multiple links with different frequency bands may be established between communication devices. For example, in addition to the first link in the 2.4 GHz band and the second link in the 6 GHz band between AP101 and STA102, a third link in the 5 GHz band may be established. Alternatively, links may be established through a plurality of different channels included in the same frequency band. For example, a 6ch link in the 2.4 GHz band may be used as the first link, and in addition, a 1ch link in the 2.4 GHz band may be established as the second link. Note that a plurality of links with the same frequency band and links with different frequency bands may coexist. For example, in addition to the 6ch link in the 2.4 GHz band between AP101 and STA102, a 1ch link in the 2.4 GHz band and a 149ch link in the 5 GHz band may be established. By establishing a plurality of connections with different frequencies between AP101 and STA102, communication can be established between STA102 and another band (for example, the 5 GHz band) even when a certain frequency band (for example, the 2.4 GHz band) is congested. Therefore, it is possible to prevent a decrease in throughput and communication delay in communication with STA102.

[0018] Note that although the wireless network 100 in FIG. 1 is composed of one AP and one STA, the number and arrangement of APs and STAs are not limited thereto. For example, in addition to the wireless network in FIG . 1, one or more STAs may be added. At this time, the frequency band, the number of links, and the bandwidth of each established link may be different for each STA.

[0019] When performing multi-link communication, AP101 and STA102 split a single data stream and transmit it to the other device via multiple links. AP101 and STA102 may also perform MIMO (Multiple-Input And Multiple-Output) communication. In this case, AP101 and STA102 have multiple antennas, with each sending different signals from its respective antennas using the same channel. The receiving side simultaneously receives all signals arriving from multiple streams using its multiple antennas, separates the signals from each stream, and decodes them. By performing MIMO communication in this way, AP101 and STA102 can communicate more data in the same amount of time compared to when MIMO communication is not performed. Furthermore, when performing multi-link communication, AP101 and STA102 may perform MIMO communication on some or all of the links.

[0020] (AP and STA configuration) Figure 2 shows an example of the hardware configuration of AP101 in this embodiment. AP101 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. Note that there may be multiple antennas.

[0021] 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.

[0022] The control unit 202 is composed of one or more processors, such as a CPU and an MPU, and controls the entire AP101 by executing a computer program stored in the memory unit 201. Alternatively, the control unit 202 may control the entire AP101 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 comprise multiple processors, such as a multi-core processor, and control the entire AP101 using these multiple processors.

[0023] 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 AP101 to perform predetermined processes.

[0024] 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. The input unit 204 and the output unit 205 may be implemented in a single module, such as a touch panel. The input unit 204 and the output unit 205 may be integrated with AP101 or may be separate components.

[0025] The communication unit 206 controls wireless communication in accordance with the IEEE 802.11be standard. In addition to the IEEE 802.11be standard, the communication unit 206 may also control wireless communication in accordance with other IEEE 802.11 series standards, or control wired communication such as wired LAN. The communication unit 206 controls the antenna 207 to transmit and receive signals for wireless communication generated by the control unit 202.

[0026] Furthermore, if AP101 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 AP101 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. AP101 communicates data such as image data, document data, and video data with STA102 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.

[0027] Antenna 207 is an antenna capable of communication in the 2.4GHz, 5GHz, and 6GHz bands. In this embodiment, AP101 has one antenna, but it may have three antennas, or it may have different antennas for each frequency band. Furthermore, if AP101 has multiple antennas, it may have a communication unit 206 corresponding to each antenna. Note that STA102 has the same hardware configuration as AP101.

[0028] Figure 3 shows a block diagram of the functional configuration of AP101 in this embodiment. STA102 has a similar configuration. Here, AP101 is assumed to include a wireless LAN control unit 301. The number of wireless LAN control units is not limited to one; there may be two, three, or more. AP101 further includes a frame generation unit 302, a transmission time control unit 303, a beacon control unit 304, a UI control unit 305, a storage unit 306, and a wireless antenna 307.

[0029] The wireless LAN control unit 301 comprises an antenna and circuit for sending and receiving wireless signals with other wireless LAN devices, and a program 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.

[0030] The frame generation unit 302 generates a wireless control frame to be transmitted by the wireless LAN control unit 301. The content of the wireless control generated by the frame generation unit 302 may be constrained by settings stored in the storage unit 306. It may also be changed by user settings from the UI control unit 305. The information of the generated frame is sent to the wireless LAN control unit 301 and transmitted to the communication partner.

[0031] The transmission time control unit 303 controls when to issue an instruction to transmit a frame, according to the time interval received from the beacon control unit 304. Following the instruction from the transmission time control unit 303, the wireless LAN control unit 301 transmits the frame generated by the frame generation unit 302.

[0032] The beacon control unit 304 instructs the frame generation unit 302 and the transmission time control unit 303 regarding the timing of beacon transmission and the information to be included in the beacon. When AP101 starts operating as an AP, it sets a time for periodically transmitting beacons in the transmission control unit 303. In addition, when the transmission time control unit 303 issues an instruction to transmit a beacon, it also indicates to the frame generation unit 302 the content to be included in the beacon. Based on the instructions, the frame generation unit 302 retrieves information from the storage unit 306.

[0033] The UI control unit 305 includes hardware related to a user interface, such as a touch panel or buttons, for receiving operations on the AP by a user (not shown) and a program to control them. The UI control unit 305 also has functions for presenting information to the user, such as displaying images or outputting audio.

[0034] 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.

[0035] (Example 1) Figure 4 shows a sequence diagram in which AP101 notifies STA102 of the channel distance of a Link where STR is possible for a candidate Association channel. This sequence shows an example of using Association Response for this notification. Here, STR stands for simultaneous transmit and receive and is defined in the IEEE 802.11 standard. STR indicates that in a pair of Links used in Multi-Link communication, transmission is performed on one Link while reception is performed on the other Link (or vice versa).

[0036] AP101 and STA102 each have a wireless LAN control unit 301 corresponding to one of the multiple links. In Figure 4, AP411 of AP101 is the wireless LAN control unit 301 for the first link, AP412 for the second link, and AP413 for the third link. Similarly, STA421 of STA102 is the wireless LAN control unit 301 for the first link, STA422 for the second link, and STA423 for the third link. In this embodiment, as an example, STA421 and AP411 are configured to process communication via channel 1 of the 2.4GHz band. STA422 and AP412 are configured to process communication via channel 5 of the 2.4GHz band. STA423 and AP413 are configured to process communication via channel 10 of the 2.4GHz band.

[0037] The processing of this sequence begins when the power to AP101 and STA102 is turned on. Alternatively, at least one of AP101 and STA102 may begin when instructed by the user or application to start Multi-Link communication. Alternatively, at least one of AP101 and STA102 may begin when the amount of data to be communicated with the other device exceeds a predetermined threshold.

[0038] First, AP101 transmits a Beacon containing its own network information on channel 1, thereby informing surrounding STAs of its own network information (S401). Network information specifically includes the transmission interval at which AP101 sends beacons and AP101's SSID. SSID stands for Service Set Identifier. In addition, AP101 may include information about its Multi-Link communication capabilities as network information in the beacon and broadcast it.

[0039] When STA102 receives the Beacon signal from AP101 transmitted on channel 1, it sends a Probe Request on channel 1 to query AP101's network information (S402). The Probe Request includes AP101's SSID. In addition, STA102 notifies AP101 of its Multi-Link communication capability information in the Probe Request.

[0040] When AP101 receives a Probe Request, it sends a Probe Response to STA102 on channel 1 as a response (S403). If AP101 did not include capability information regarding Multi-Link communication in the Beacon, it includes such capability information in the Probe Response and sends it. Alternatively, AP101 may include only some of the capability information regarding Multi-Link communication in the Beacon and include the remaining information or all of the information in the Probe Response.

[0041] By performing steps S401 to S403, AP101 and STA102 can exchange information regarding their respective Multi-Link communication capabilities.

[0042] Next, STA102 sends an Association Request to AP101 on channel 1 as a request to connect to the network formed by AP101 (S404). Here, STA102 may include information about STA102's capabilities regarding Multi-Link communication in the Association Request. STA102 may also determine the capability information to send in S404 based on the Multi-Link communication capability information of AP101 detected in at least one of S401 or S403. For example, even if STA102 can combine links in the 2.4GHz and 5GHz bands, AP101 may only support Multi-Link communication using multiple links within the 2.4GHz band. In this case, STA102 may send only capability information regarding the establishment of multiple links in the 2.4GHz band as the capability information to send in this step. Furthermore, in this embodiment, STA102 transmits capability information regarding its own device's Multi-Link communication in S402, but it is not limited to this, and capability information may not be transmitted in S402, and may only be transmitted in this step. Alternatively, STA102 may include request information required when performing Multi-Link communication in the Association Request. The request information requested by STA102 may be indicated by capability information regarding Multi-Link, or it may be indicated by another element.

[0043] When AP101 receives an Association Request, it sends an Association Response to STA102 on channel 1 (S405). The Association Response sent here includes the STR-enabled channel distance for one or more transmission bandwidths. The STR-enabled channel distance is information indicating how far apart multiple links used in Multi-Link communication must be on the frequency axis to perform transmission and reception in parallel, i.e., whether STR is possible. In other words, the STR-enabled channel distance is the distance on the frequency axis between the frequency channels used by each of the multiple links used in Multi-Link communication. For example, if STR is possible when the links are separated by 5 channels, the STR-enabled channel distance is 5 (or 5ch). This value will vary depending on the device. In this embodiment, the STR-enabled channel distance of AP101 is set to the distance of 5 channels for a 20MHz bandwidth, the distance of 10 channels for a 40MHz bandwidth, the distance of 20 channels for an 80MHz bandwidth, and the distance of 40 channels for a 160MHz bandwidth. Furthermore, the STR-enabled channel distance may consist only of distances with a bandwidth of 20 MHz, or it may include additional bandwidths not mentioned in the above example, such as a bandwidth of 320 MHz. How to specifically include the STR-enabled channel distance in the Association Response will be explained later in the explanation of Figure 6. The method for determining the channel distance will be explained later in the explanation of Figure 7. In this embodiment, the timing for determining each channel distance is immediately before sending the Association Response. However, it is not limited to the timing of sending the Association Response; it may also be the timing when a Probe Request is received, the timing before sending a Beacon, etc. Alternatively, it may be the timing when a change in the communication state is detected. In addition, for example, it may be the timing when the transmission power of AP101 is changed, the timing when the transmission power from STA102 changes, the timing when there is an increase or decrease in the packet loss rate in communication, the timing when there is an increase or decrease in the packet error rate in communication, etc. Alternatively, it may be determined periodically.If all channel pairs of the association candidate are STR-enabled, it is not necessary to notify the STR-enabled channel distance per transmission bandwidth. Alternatively, if none of them are STR-enabled, it is not necessary to notify the STR-enabled channel distance per transmission bandwidth.

[0044] Furthermore, the Association Response sent here includes operational information determined by AP101 for multi-link communication with STA102. In addition, if STA102 has sent an Association Request in S404 that includes the operational information it requests, AP101 may send an Association Response that includes whether or not it can fulfill that request.

[0045] When STA102 receives an Association Response, it can detect the simultaneous transmit / receive performance of the candidate Links from AP101's perspective based on the STR-possible channel distance for each transmit bandwidth included in the response. Specifically, AP101 determines that simultaneous transmit and receive is possible for a channel pair if the channels are separated by the STR channel distance for each transmit bandwidth. For example, suppose the candidate Links for Association are 1ch, 5ch, and 6ch, and the STR-possible channel distance for 20MHz is 5. Then, for the pair of 1ch and 6ch, which are separated by 5 channels, AP101 determines that it is possible to transmit at 20MHz on one link while receiving at 20MHz on the other. On the other hand, for the pair of 1ch and 5ch, since the channel distance is less than 5 channels, AP101 determines that it is not possible to transmit at 20MHz on one link while receiving at 20MHz on the other. For example, suppose the candidate Links for Association are 1ch, 10ch, and 36ch, and the STR-possible channel distance for 40MHz is 10. In this case, with the pair of channels 10 and 36, which are separated by 26 channels, it is determined that it is possible to transmit at 40 MHz on one link while receiving at 20 MHz on the other link. On the other hand, with the pair of channels 1 and 10, since the channel distance is less than 10 channels, it is determined that it is not possible to transmit at 40 MHz on one link while receiving at 20 MHz on the other link. In this example, the receiving bandwidth is fixed at 20 MHz even though the transmitting bandwidth is not 20 MHz (it is 40 MHz). Alternatively, this receiving bandwidth could be made to match the transmitting bandwidth. That is, for example, suppose there are three candidate links for association: channels 1, 10, and 36, and the STR-possible channel distance for 40 MHz is 10. Then, with the pair of channels 10 and 36, which are separated by 26 channels, it is determined that it is possible to transmit at 40 MHz on one link while receiving at 40 MHz on the other link. On the other hand, with a pair of channels 1 and 10, the channel distance is less than 10 channels, so it is determined that it is not possible to transmit at 40MHz on one link while receiving at 40MHz on the other link.

[0046] STA102 sends a Reassociation Request to AP101 (S406) with the aim of changing the association details determined in the Association Response. For example, if channels 1, 5, and 10 were associated by the Association Response in S404, but the 20MHz STR-possible channel distance is 5, it is determined that channels 1 and 5 cannot transmit and receive simultaneously. To improve this, STA102 sends a request to AP101 to reassociate channels 1, 6, and 11, for example. Alternatively, a Disassociation request may be sent instead of a Reassociation Request. Alternatively, data transmission may be performed without sending a Reassociation Request. In that case, since channels 1 and 5 cannot transmit and receive simultaneously, synchronization control to prevent one channel from transmitting while the other is receiving, or detection of packet reception errors and attempts to retransmit, will be necessary for accurate reception. Alternatively, the system may process the channel pair that cannot transmit and receive simultaneously to perform low-priority communication or communication that does not require accurate reception. For example, the TID (Traffic IDentifier) ​​assignment may be changed.

[0047] Figure 5 shows an example of the structure of an Association Response frame sent by AP101 to STA102. The Capability Information element (501) indicates the requested optional function or the optional function that AP101 supports. The Status Code element (502) indicates whether the Request to which the Response is being sent was successful or failed. The AID element (503) indicates the Association IDentifier assigned by AP101. 504 indicates the Capability information of the channel on which AP101 is sending the Association Response frame. The Capability information includes, for example, the HT Capabilities element (505) when communicating in accordance with IEEE802.11n. Also, for example, the VHT Capabilities element (506) is stored when communicating in accordance with IEEE802.11ac, but is not limited to this.

[0048] The ML (Multi-Link) element (507) indicates that the AP supports Multi-Link communication. The Association Response frame of an AP that does not support Multi-Link communication does not include an ML element. Furthermore, the ML element (507) consists of an Element ID field (511) that identifies the element, a Length field (512) that indicates the data length of the element, and element-specific information. The element-specific information consists of Common Info (513) which contains information common to all links, and Per Link Info (514) which contains information specific to each link.

[0049] 521-525 indicate information included in Common Info. MLD MAC Address 521 indicates the MLD (Multi-Link Device) MAC (Medium Access Control) Address of AP101. 20MHz STR Distance 522 indicates the STR-enabled channel distance, which is the distance between channels that are STR (Simultaneous Tx Rx) enabled channels with a transmit bandwidth of 20MHz. If a value of 5 is stored, for example, it indicates that if two channels are 5ch or more apart for AP101, it can transmit on one channel at 20MHz while receiving on the other channel at 20MHz. 40MHz STR Distance 523 indicates the distance between channels that are STR-enabled channels with a transmit bandwidth of 40MHz. If a value of 10 is stored, for example, it indicates that if two channels are 10ch or more apart for AP101, it can transmit on one channel at 40MHz while receiving on the other channel at 20MHz. 80MHz STR Distance524 indicates the distance between channels that are STR-enabled channels with a transmit bandwidth of 80MHz. If a value of 20 is stored, for example, it indicates that if the two channels are 20ch or more apart for AP101, it is possible to transmit on one channel at 80MHz while receiving on the other channel at 20MHz. Other bandwidth ranges, such as 160MHz STR Distance, may also be available. Alternatively, high-bandwidth information that AP101 does not support may be omitted. Note that while this indicates the distance between channels (ch), it may also indicate the distance between frequencies (Hz). Note that here the receive bandwidth during simultaneous transmission and reception is fixed at 20MHz, but it may be matched with the transmit bandwidth. That is, it is possible to transmit with a bandwidth of 40MHz while receiving with a bandwidth of 40MHz (the same applies to 80MHz and 160MHz).

[0050] By including this information, the Association Response frame allows AP101 to notify STA102 that it supports Multi-Link communication and the STR-enabled channel distance for each transmission bandwidth. The field names and bit positions and sizes are not limited to this example, and similar information may be stored with different field names, in different orders, or in different sizes.

[0051] Figure 6 shows a flowchart for determining the STR-enabled channel distance in 20MHz transmission for AP101. This flowchart is implemented by the processor of the control unit 202 of AP101 executing a program stored in the memory unit 201.

[0052] First, AP101 searches for pairs of Ch[2] and subsequent channels and Ch[1] in order until it finds a pair that can be strung (S601). Here, Ch[n] is the nth channel from the lowest frequency among the association candidate channels that can communicate with a bandwidth of 20 MHz. In this embodiment, the association candidate channel group is 1ch, 5ch, 10ch, 36ch, 40ch, 64ch, and 100ch. For example, Ch[1] becomes 1ch and Ch[7] becomes 100ch. In this case, the system checks whether the pair of 1ch and 5ch is STR-enabled, and if not, it checks whether the pair of 1ch and 10ch is STR-enabled, and so on, up to the pair of Ch[1] and Ch[7]. The method for determining whether a given channel pair is STR-enabled in 20MHz transmission is shown in Figure 7 below. In this embodiment, it is assumed that 1ch and 10ch are determined to be STR-enabled.

[0053] Next, AP101 determines in S601 whether a STR-enabled channel pair has been found (S602). If found, it proceeds to S603. If not found, the STR-enabled channel distance at 20MHz is determined to be either none or an unrealistically large value, and this flow ends. In this example, a pair of channels 1 and 10 was found, so it proceeds to S603.

[0054] Next, the found STR-capable channel pair is set as Ch[x] and Ch[y] (where x < y) (S603). In this embodiment, x = 1 and y = 3.

[0055] Next, set i = x (S604). In this embodiment, i = 1.

[0056] Next, AP101 determines whether Ch[i + 2] exists as a channel that is a candidate for association and is capable of 20 MHz communication. If it exists, proceed to S606. If it does not exist, end this flow with (Ch[y] - Ch[x]) as the STR-capable channel distance at 20 MHz. In this embodiment, since i = 1, Ch[3] exists as 10ch, and proceed to S606.

[0057] Next, set i = i + 1 and name it j = i + 2 (S606). In this embodiment, i = 2 and j = 3.

[0058] Next, AP101 searches in order for the pairs of channels after Ch[j] and Ch[i] until an STR-capable pair is found (S607). In this embodiment, first, it checks whether the pair of Ch[2] and Ch[3], that is, 5ch and 10ch, is STR-capable. If not, it checks whether the pair of Ch[2] and Ch[4], that is, 5ch and 36ch, is STR-capable, and checks this in order up to the pair of Ch[2] and Ch[7]. In this embodiment, assume that Ch[2] and Ch[4] are determined to be STR-capable.

[0059] Next, AP101 determines at S608 whether a channel pair that can be STR is found at S607 and whether the channel distance of that pair is less than (Ch[y] - Ch[x]). If found and less than (Ch[y] - Ch[x]), it proceeds to S609. If not found, or if found but greater than or equal to (Ch[y] - Ch[x]), it proceeds to S605. In this embodiment, since the channel distance of the channel found at S607 is (Ch[4] - Ch[2]) = 36 - 5 = 31 and (Ch[y] - Ch[x]) = 10 - 1 = 9, it proceeds to S605 with i = 2 remaining. By proceeding through S605 and subsequent steps again with i = 2 remaining, it will search for a channel pair that can be STR and has a closer channel distance, specifically Ch[3] = 10. By proceeding through S605 and subsequent steps again with the updated i remaining, it will search for a channel pair that can be STR and has a closer channel distance.

[0060] Next, AP101 sets the channel pair that can be STR and has a closer channel distance, found at S608, as Ch[x] and Ch[y] (where x < y) at S609). In this embodiment, assume that finally Ch[1] and Ch[3] are determined to be the channel pair that can be STR and has the closest channel distance. However, in this case, since this channel pair has already been identified at S603, it does not proceed to S609.

[0061] Finally, AP101 determines (S610) the channel distance of the found channel pair that can be STR and has the closest channel distance as the STR - possible channel distance at in 20 MHz, and ends this flow.

[0062] Although this flowchart has been described with a focus on transmission in a 20 - MHz bandwidth, the STR - possible channel distance can be determined in the same way for 40 MHz, 80 MHz, etc. In the case of determining the STR - possible channel distance between a total 160 - MHz bandwidth divided into two 80 - MHz bands and other channels, it can be determined by looking only at the 80 - MHz band that is closer to the other channel. Similarly, for other divided bands, the STR - possible channel distance can be determined.

[0063] Figure 7 shows a flowchart for determining whether the channel A and channel B pair of AP101 can be STR'd during 20MHz transmission. This flowchart is implemented by the processor of the control unit 202 of AP101 executing a program stored in the memory unit 201.

[0064] First, AP101 detects the amount of radio noise (B) received by AP101 on channel B when AP101 transmits a radio frame at 20MHz on channel A (S701). The unit of this radio noise amount is, for example, dBm. The processing in S701 may be to detect the amount of radio noise at a time when some radio frame transmission is necessary, or a dummy frame (a frame with no meaningful data content) may be transmitted on channel A for this radio noise amount detection.

[0065] Next, AP101 detects the RSSI (Received Signal Strength Indicator) (B) that AP101 receives on channel B at 20MHz when STA102 transmits a wireless frame at 20MHz on channel B (S702). The unit of this RSSI is, for example, dBm. S702 may detect the RSSI when some wireless frame transmission arrives, or it may pre-instruct STA102 to transmit a dummy frame on channel B for the purpose of detecting the amount of wireless noise.

[0066] Next, AP101 detects the amount of radio noise (A) received by AP101 on channel A when AP101 transmits a radio frame on channel B at 20MHz (S703). The process in S703 may be performed to detect the amount of radio noise at a time when some radio frame transmission is necessary, or a dummy frame may be transmitted on channel B for this radio noise detection.

[0067] Next, AP101 detects the RSSI(A) received by AP101 on channel A at 20MHz when STA102 transmits a wireless frame at 20MHz on channel A (S704). The processing in S704 may involve detecting the RSSI at the timing of any wireless frame transmission, or AP101 may have previously requested STA102 to transmit a dummy frame on channel A for the purpose of detecting the amount of wireless noise.

[0068] Next, AP101 determines whether (RSSI(A) - Wireless Noise Amount(A)) and (RSSI(B) - Wireless Noise Amount(B)) are each above a predetermined value (S705). If they are above the predetermined value, the process proceeds to S706. If they are below the predetermined value, the process proceeds to S707. The predetermined value here may be a fixed value, or it may be determined appropriately based on the communication status. For example, if the link rate on channel A is higher than the predetermined rate, the predetermined value used for comparison with (RSSI(A) - Wireless Noise Amount(A)) is increased. This is because a higher link rate requires a higher SNR (Signal-to-noise Ratio) for high-quality communication. Alternatively, the decision may be made based on only one of either RSSI or the wireless noise amount. For example, it may be determined whether RSSI(A) and RSSI(B) are each above a predetermined value, or whether Wireless Noise Amount(A) and Wireless Noise Amount(B) are each below a predetermined value.

[0069] Next, in S706, AP101 determines that the pair of channel A and channel B is STRable and ends this flow. Then, in S707, AP101 determines that the pair of channel A and channel B is not STRable and ends this flow.

[0070] The flowchart above describes how to determine whether a channel A and channel B pair can be STR'd when transmitting at 20MHz. The flowchart is similar for 40MHz and 80MHz, simply changing the transmission bandwidth to 40MHz or 80MHz, but using 20MHz for the reception bandwidth. Alternatively, it may match the transmission bandwidth, or match the bandwidth of the association candidate. A larger bandwidth requires less SNR for high-quality communication, so the predetermined value may be changed accordingly.

[0071] In this embodiment, AP101 sends an Association Response including the STR-enabled channel distance for each radio bandwidth. This allows STA102 to infer which channel pairs are STR-enabled and which are not in the Multi-Link communication. For the purpose of efficient communication, STA102 can change the channel being used, establish a new channel, or transmit high-priority data on STR-enabled channels. In this embodiment, AP101 notifies STA102 of the STR-enabled channels for each radio frequency bandwidth, but this is not limited to this; STA102 may also notify AP101.

[0072] In this embodiment, the STR-enabled channel is included in the Association Response, but is not limited to this. For example, it may be included in management frames such as Beacon, Probe Request, Probe Response, Association Request, Authentication, and Action.

[0073] (Example 2) In Example 1, AP101 measured the amount of radio noise and RSSI while communicating with STA102, determined the STR-possible channel distance based on these, and notified STA102. In this example, we describe a configuration in which the amount of radio noise related to transmission is measured and stored in advance, and the STR-possible channel distance is determined based on the stored amount of radio noise while communicating with STA102.

[0074] The parts described in Figures 4 to 6 are the same as in Example 1, so their explanation will be omitted.

[0075] Figure 8 is a flowchart showing the process by which AP101 detects transmission noise during 20MHz transmission for the channel A and channel B pair before communicating with STA102. This flowchart is implemented when the processor in the control unit 202 of AP101 executes a program stored in the memory unit 201.

[0076] First, AP101 determines (S801) whether there are any transmission powers for which the transmission noise amount has not yet been detected in S803-S804, as described below. If there are, it proceeds to S802. If not, this flow ends. Since AP101 has not yet communicated with STA102, it is assumed that the transmission power to STA102 has not been determined, and therefore it is necessary to measure the transmission noise amount for all candidate transmission powers in advance. Alternatively, if the transmission power to STA102 has been determined in advance, S801 may be skipped and the process may proceed to S802.

[0077] Next, AP101 sets the transmit power to the wireless LAN control unit 301 to the transmit power value determined in S801 for which no transmit noise has yet been detected (S802).

[0078] Next, when AP101 transmits a wireless frame at 20MHz on channel A, AP101 detects the amount of transmission noise (B) received by AP101 on channel B and records it in the storage unit 306 along with the transmission power (S803). The unit of this transmission noise amount is, for example, dBm. The process in S803 may be performed to detect the amount of wireless noise at a timing when it is necessary to transmit a wireless frame, or a dummy frame may be transmitted on channel A for this purpose of detecting the amount of wireless noise.

[0079] Next, when AP101 transmits a wireless frame at 20MHz on channel B, AP101 detects the amount of transmission noise (A) received by AP101 on channel A and records it in the storage unit 306 along with the transmission power (S804). The unit of this transmission noise amount is, for example, dBm. The process in S804 may be performed to detect the amount of wireless noise at a timing when it is necessary to transmit a wireless frame, or a dummy frame may be transmitted on channel A for this purpose of detecting the amount of wireless noise.

[0080] This flow may be executed after the AP101 is powered on, or before the AP101 reaches the user, for example, before it leaves the factory, or it may copy and retain the detection results of another similar device.

[0081] Figure 9 is a flowchart for determining whether the channel A and channel B pair of AP101 can be STR'd during 20MHz transmission. This flowchart is implemented by the processor of the control unit 202 of AP101 executing a program stored in the memory unit 201.

[0082] First, when AP101 transmits a wireless frame at 20MHz on channel A, AP101 detects the amount of transmission noise (B) received by AP101 on channel B from the storage unit 306 (S901). AP101 selects the transmission noise amount (B) whose associated transmission power matches the transmission power currently set for AP101. Alternatively, the associated transmission power may be the value closest to the transmission power currently set for AP101, or the smallest value exceeding the transmission power currently set for AP101.

[0083] Next, AP101 detects the amount of steady-state noise (B) received by AP101 on channel B at times other than when AP101 on channel A is transmitting wireless frames at 20MHz (S902).

[0084] Next, AP101 detects the RSSI (Received Signal Strength Indicator) (B) that AP101 receives on channel B at 20MHz when STA102 transmits a wireless frame at 20MHz on channel B (S702).

[0085] Next, when AP101 transmits a wireless frame on channel B at 20MHz, AP101 detects the amount of transmission noise (A) received by AP101 on channel A from the storage unit 306 (S904). The transmission power associated with that amount of transmission noise (A) is selected to match the transmission power currently set for AP101. Alternatively, the transmission power associated with that amount of transmission noise (A) may be the value closest to the transmission power currently set for AP101, or the smallest value exceeding the transmission power currently set for AP101.

[0086] Next, AP101 detects the amount of steady-state noise (A) received by AP101 on channel A at times other than when AP101 on channel B is transmitting wireless frames at 20MHz (S905).

[0087] Next, AP101 detects the RSSI (Received Signal Strength Indicator) (A) that AP101 receives on channel A at 20MHz when STA102 transmits a wireless frame at 20MHz (S704).

[0088] Next, AP101 determines whether (RSSI(A) - Transmit Noise Amount(A) - Steady-State Noise Amount(A)) and (RSSI(B) - Transmit Noise Amount(B) - Steady-State Noise Amount(B)) are each above a predetermined value (S907). If they are above the predetermined value, the process proceeds to S706. If they are below the predetermined value, the process proceeds to S707. The predetermined value here may be a fixed value, or it may be determined appropriately based on the communication state. For example, if the link rate on channel A is higher than the predetermined rate, the predetermined value used for comparison with (RSSI(A) - Transmit Noise Amount(A) - Steady-State Noise Amount(A)) is increased. This is because a higher link rate requires a higher SNR for high-quality communication. Also, for simplicity, one or more RSSI, transmit noise amount, or steady-state noise amount may be treated as 0. For example, it may be determined whether RSSI(A) and RSSI(B) are each above a predetermined value, or whether transmit noise amount(A) and transmit noise amount(B) are each below a predetermined value.

[0089] Since S706 and S707 are the same as in Example 1, their explanation will be omitted.

[0090] The above describes a flowchart for determining whether a channel A and channel B pair can be STR'd when transmitting at 20MHz. The flowchart is similar for 40MHz and 80MHz, but the transmission bandwidth is changed to 40MHz or 80MHz; however, the reception bandwidth remains 20MHz. Alternatively, it may match the transmission bandwidth, or match the bandwidth of the association candidates. It may also be the maximum bandwidth of the association candidates, or the minimum bandwidth of the association candidates. A larger bandwidth requires less SNR for high-quality communication, so the predetermined value may be changed accordingly.

[0091] In this embodiment, AP101 sends an Association Response that includes the STR-enabled channel distance for each radio bandwidth, which is determined based on the amount of transmission noise measured before communicating with STA102. This allows STA102 to infer which channel pairs are STR-enabled and which are not in the Multi-Link communication. For the purpose of efficient communication, STA102 can change the channel being used, establish a new channel, or transmit high-priority data on the STR-enabled channel. In this embodiment, AP101 notifies STA102 of the STR-enabled channels for each radio frequency bandwidth, but the system is not limited to this, and STA102 may also notify AP101.

[0092] In this embodiment, the STR-enabled channel is included in the Association Response, but is not limited to this. For example, it may be included in management frames such as Beacon, Probe Request, Probe Response, Association Request, Authentication, and Action.

[0093] (Other examples) The embodiments described above are examples, and the technical scope of the present invention is not limited thereto. The present invention includes various modifications other than those described above. In the embodiments described above, the IEEE 802.11be standard was used as an example of a wireless LAN standard, but the invention is also applicable to various standards (IEEE 802.11x), including legacy and successor standards of the IEEE 802.11 series, as well as other wireless standards of the same type.

[0094] Furthermore, 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]

[0095] 100 Networks 101 AP 102 STA 103 Multi-Link

Claims

1. A communication device compliant with the IEEE (Institute of Electrical and Electronics Engineers) 802.11 series standard, capable of performing Multi-Link communication with other communication devices via a first link using a first frequency and a second link using a second frequency different from the first frequency, The other communication device has a transmitting means for transmitting first information relating to the difference between the first frequency and the second frequency necessary for performing STR (simultaneous transmit and receive) communication, A communication device characterized in that the difference between the first frequency and the second frequency is shown by multiplying a predetermined bandwidth and the first information.

2. The communication device according to claim 1, characterized in that it transmits the first information in association with the other communication device.

3. The communication device according to claim 1 or 2, characterized in that the first information is included in Common Info included in Multi-Link element.

4. The communication device according to any one of claims 1 to 3, characterized in that the first information is the difference between the channel used by the first link and the channel used by the second link, which is necessary for STR communication.

5. The first frequency is the frequency used by the first frequency channel, and the second frequency is the frequency used by the second frequency channel. The communication device according to any one of claims 1 to 4, characterized in that the first frequency band including the first frequency channel is the same frequency band as the second frequency band including the second frequency channel.

6. The first frequency is the frequency used by the first frequency channel, and the second frequency is the frequency used by the second frequency channel. The communication device according to any one of claims 1 to 4, characterized in that the first frequency band including the first frequency channel is a different frequency band from the second frequency band including the second frequency channel.

7. The communication device according to claim 5 or 6, characterized in that the first frequency band is one of the 2.4 GHz band, 5 GHz band, 6 GHz band, or 60 GHz band, and the second frequency band is one of the 2.4 GHz band, 5 GHz band, 6 GHz band, or 60 GHz band.

8. The communication device according to any one of claims 1 to 7, characterized in that the predetermined bandwidth is 20 MHz.

9. The aforementioned communication device further, The noise that the transmission of the communication device at the first frequency imposes on the second frequency of the communication device, Noise detected at the second frequency of the communication device when the communication device is not transmitting using the first frequency, The transmission power detected at the second frequency of the communication device by the transmission using the second frequency of the other communication device, The noise that the transmission using the second frequency of the communication device imposes on the first frequency of the communication device, Noise detected at the first frequency of the communication device when the communication device is not transmitting using the second frequency, The transmission power detected at the first frequency of the communication device by the transmission using the first frequency of the other communication device, The communication device according to any one of claims 1 to 8, characterized in that it has a determination means for determining the difference between the first frequency and the second frequency based on one or more of the following values.

10. The noise that the transmission using the first frequency of the communication device imposes on the second frequency of the communication device, The noise that the transmission using the second frequency of the communication device imposes on the first frequency of the communication device is, The communication device according to claim 9, characterized in that it is kept in the communication device in advance.

11. The noise that the transmission using the first frequency of the communication device imposes on the second frequency of the communication device, The noise that the transmission using the second frequency of the communication device imposes on the first frequency of the communication device is, The communication device according to claim 9, characterized in that it measures by transmitting a wireless frame.

12. A communication method for a communication device compliant with the IEEE 802.11 series standard, which enables Multi-Link communication with other communication devices via a first link using a first frequency and a second link using a second frequency different from the first frequency, The device has a transmission step of transmitting to the other communication device first information relating to the difference between the first frequency and the second frequency necessary for performing STR (simultaneous transmit and receive) communication, A communication method characterized in that the difference between the first frequency and the second frequency is shown by multiplying them using a predetermined bandwidth and the first information.

13. A program for operating a computer as a communication device according to any one of claims 1 to 11.

14. A communication device compliant with the IEEE 802.11 series standard that can perform Multi-Link communication with other communication devices by a first link using a first frequency and a second link using a second frequency different from the first frequency, The device has receiving means for receiving first information relating to the difference between the first frequency and the second frequency necessary for performing STR (simultaneous transmit and receive) communication from the other communication device, A communication device characterized in that the difference between the first frequency and the second frequency is shown by multiplying a predetermined bandwidth and the first information.

15. The communication device according to claim 14, characterized in that it receives the first information in an association with the other communication device.

16. The communication device according to claim 14 or 15, characterized in that the first information is included in Common Info included in Multi-Link element.

17. The communication device according to any one of claims 14 to 16, characterized in that the first information is the difference between the channel used by the first link and the channel used by the second link, which is necessary for STR communication.

18. The first frequency is the frequency used by the first frequency channel, and the second frequency is the frequency used by the second frequency channel. The communication device according to any one of claims 14 to 17, characterized in that the first frequency band including the first frequency channel is the same frequency band as the second frequency band including the second frequency channel.

19. The first frequency is the frequency used by the first frequency channel, and the second frequency is the frequency used by the second frequency channel. The communication device according to any one of claims 14 to 17, characterized in that the first frequency band including the first frequency channel is a different frequency band from the second frequency band including the second frequency channel.

20. The communication device according to claim 18 or 19, characterized in that the first frequency band is any of the 2.4 GHz band, 5 GHz band, 6 GHz band, and the second frequency band is any of the 2.4 GHz band, 5 GHz band, 6 GHz band, and 60 GHz band.

21. The communication device according to any one of claims 14 to 20, characterized in that the predetermined bandwidth is 20 MHz.

22. A communication method for a communication device compliant with the IEEE 802.11 series standard, which enables Multi-Link communication with another communication device by a first link using a first frequency and a second link using a second frequency different from the first frequency, The device has a receiving step of receiving first information relating to the difference between the first frequency and the second frequency necessary for performing STR (simultaneous transmit and receive) communication from the other communication device, A communication method characterized in that the difference between the first frequency and the second frequency is shown by multiplying them using a predetermined bandwidth and the first information.

23. A program for operating a computer as a communication device according to any one of claims 14 to 21.

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