Communication apparatus, control method, and storage medium

Abstract

The AP 102 controls so that the FILS discovery frames and / or unsolicited probe response frames are not transmitted at an interval of 20 TUs (time units) or less when multiple different links are being used for communication via multiple different channels, and the FILS discovery frames and / or unsolicited probe response frames are transmitted at an interval of 20 TUs or less when multiple links are not being used for communication.

Description

TECHNICAL FIELD

[0001] The present application relates to transmission and reception of information related to communication in wireless communication. BACKGROUND

[0002] The IEEE 802.11 series is known as a WLAN communication standard established by IEEE (Institute of Electrical and Electronics Engineers). Note that WLAN is an abbreviation of Wireless Local Area Network. The IEEE 802.11 series standards include IEEE 802.11a / b / g / n / ac / ax standards. Patent Literature 1 describes that wireless communication according to the IEEE 802.11ax standard is performed by OFDMA (Orthogonal Frequency Division Multiple Access).

[0003] According to the IEEE 802.11ax standard, in addition to a beacon frame, an AP can transmit a FILS discovery frame at a shorter interval than the beacon frame to notify a STA of information related to wireless communication. In addition to or instead of the FILS discovery frame, an unsolicited probe response frame can be transmitted.

[0004] In IEEE, in order to achieve further improvement of throughput and frequency utilization efficiency, development of IEEE 802.11be standard, which will be a new standard in the IEEE 802.11 series, is in progress. In the development of the IEEE 802.11be standard, multi-link communication that allows one AP to establish multiple links with one STA (station) in a frequency band such as 2.4 GHz, 5 GHz, and 6 GHz band for simultaneous communication is considered.

[0005] PRIOR ART DOCUMENTS

[0006] PATENT LITERATURE

[0007] Patent Literature 1: Japanese Patent Application Publication No. 2018-50133 SUMMARY

[0008] PROBLEMS TO BE SOLVED BY THE INVENTION

[0009] When an AP that supports multi-link communication performs multi-link communication, the AP can store information related to multi-link communication in a FILS discovery frame or an unsolicited probe response frame to be transmitted by the AP.

[0010] However, this causes an increase in the amount of information contained in these frames, which can lead to an increase in communication overhead depending on the frequency of sending frames.

[0011] In view of the above problem, an object of the present application is to suppress communication overhead by appropriately sending a FILS discovery frame and / or an unsolicited probe response frame.

[0012] Solution to the problem

[0013] To achieve the above object, the present application provides a communication apparatus including: an establishing unit configured to establish a plurality of links with other communication apparatuses via a plurality of different channels; and a control unit configured to control so that, when communication is being performed using the plurality of links established by the establishing unit, a FILS discovery frame and / or an unsolicited probe response frame is not sent at an interval of 20 TUs (Time Units) or less, and when communication is not being performed using the plurality of links established by the establishing unit, a FILS discovery frame and / or an unsolicited probe response frame is sent at an interval of 20 TUs or less. BRIEF DESCRIPTION OF DRAWINGS

[0014] Figure 1 is a diagram showing an example of a configuration of a network in which the AP 102 participates.

[0015] Figure 2 is a diagram showing an example of a hardware configuration of the AP 102.

[0016] Figure 3 is a diagram showing an example of a functional configuration of the AP 102.

[0017] Figure 4 is a sequence diagram showing an example of processing performed when the AP 102 communicates with the STA 103 via a single link.

[0018] Figure 5 is a sequence diagram showing an example of processing performed when the AP 102 communicates with the STA 103 via a plurality of links.

[0019] Figure 6 is a sequence diagram showing an example of processing performed when the AP 102 communicates with the STA 103 via a plurality of links.

[0020] Figure 7 is a flowchart showing processing performed when the AP 102 performs multi-link communication or single-link communication.

[0021] Figure 8 is a flowchart showing processing performed when the AP 102 sends a beacon frame while performing single-link communication.

[0022] Figure 9 is a flowchart showing processing performed when the AP 102 transmits a beacon frame when performing multi-link communication.

[0023] Figure 10 is a flowchart showing another processing performed when the AP 102 transmits a beacon frame when performing multi-link communication. DETAILED DESCRIPTION

[0024] Embodiments of the present application are described in detail below with reference to the accompanying drawings. Note that the configurations shown in the following embodiments are merely examples, and the present application is not limited to these configurations shown below.

[0025] Figure 1 A configuration of a network in which an AP (access point) 102 according to the present embodiment participates is shown. The AP 102 is a communication device for establishing a network 101. Note that the network 101 is a wireless network.

[0026] A STA (station) 103 is a communication device that participates in the network 101. Each communication device supports the IEEE 802.11be (EHT) standard, and can perform wireless communication according to the IEEE 802.11be standard via the network 101. Note that IEEE is an abbreviation for Institute of Electrical and Electronics Engineers.

[0027] EHT is an abbreviation for Extremely High Throughput. Note that EHT can be interpreted as an abbreviation for Extreme High Throughput. Each communication device is capable of communicating in a frequency band of a 2.4 GHz band, a 5 GHz band, and a 6 GHz band. The frequency band used by each communication device is not limited to these frequency bands, and other different frequency bands such as a 60 GHz band can be used. Each communication device can use a bandwidth of 20 MHz, 40 MHz, 80 MHz, 160 MHz, or 320 MHz in communication.

[0028] The AP 102 and the STAs 103 can perform multi-user (MU) communication in which signals to multiple users are multiplexed by performing OFDMA communication according to the IEEE 802.1 lbe standard. OFDMA is an abbreviation for Orthogonal Frequency Division Multiple Access. In OFDMA communication, a portion of a frequency band (RU, resource unit) is allocated to each STA in a manner in which there is no overlap, and the carriers allocated to each STA are orthogonal to each other. This enables the AP to communicate in parallel with multiple STAs.

[0029] The AP 102 and the STA 103 establish links via a plurality of frequency channels, thereby performing multi-link communication. The AP that performs multi-link communication is also referred to as an AP MLD (multi-link device). Here, the frequency channel refers to a frequency channel defined in the IEEE 802.11 series standards and capable of performing wireless communication according to the IEEE 802.11 series standards. In the IEEE 802.11 series standards, a plurality of frequency channels are defined in each of the 2.4 GHz, 5 GHz, and 6 GHz bands. According to the IEEE 802.11 series standards, 20 MHz is assigned as the bandwidth of each frequency channel. By combining adjacent frequency channels, a bandwidth of 40 MHz or more can be used in one frequency channel. For example, the AP 102 can establish a first link 104 via a first frequency channel in the 2.4 GHz band and a second link 105 via a second frequency channel in the 5 GHz band with the STA 103, thereby enabling communication with the STA 103 via the two links. In this case, the AP 102 maintains the second link 105 via the second frequency channel in parallel with the first link 104 via the first frequency channel. In this way, the AP 102 can increase the throughput in communication with the STA 103 by establishing links with the STA 103 via a plurality of frequency channels. Note that in multi-link communication, the AP 102 and the STA 103 can establish a plurality of links having different frequency bands. For example, in addition to the first link 104 in the 2.4 GHz band and the second link 105 in the 5 GHz band, the AP 102 and the STA 103 can establish a third link in the 6 GHz band. Alternatively, links can be established via a plurality of different channels included in the same frequency band. For example, a first link 104 via 1 ch in the 2.4 GHz band and a second link 105 via 5 ch in the 2.4 GHz band can be established. Note that a mixture of links in the same frequency band and links in different frequency bands is also allowed. For example, in addition to the first link 104 via 1 ch in the 2.4 GHz band and the second link 105 via 5 ch in the 2.4 GHz band, the AP 102 and the STA 103 can establish a third link via 36 ch in the 5 GHz band. If a plurality of connections in different frequency bands with the STA 103 are established, the AP 102 can communicate with the STA 103 via different bands even when one band is congested, and thus can prevent the throughput in communication with the STA 103 from decreasing.

[0030] In the multi-link communication, the multiple links established between the AP 102 and the STA 103 should be at least different in frequency channel. In the multi-link communication, the multiple links established between the AP 102 and the STA 103 should be at least 20 MHz apart in frequency channel. In the present embodiment, it is assumed that the AP 102 and the STA 103 establish the first link 104 and the second link 105, but three or more links can be established.

[0031] Note that when the multi-link communication is performed, the AP 102 establishes multiple wireless networks corresponding to the respective links. In this case, the AP 102 has multiple APs inside, which are each controlled to establish a wireless network for the AP. The APs provided inside the AP 102 can be one or more physical APs, or can be multiple virtual APs configured on one physical AP. When multiple links are established in frequency channels belonging to a common frequency band, the multiple links can use a common wireless network.

[0032] When the multi-link communication is performed, the AP 102 and the STA 103 divide one data and transmit the divided data to the counterpart device via the multiple links. Alternatively, the AP 102 and the STA 103 can each transmit the same data via the multiple links, so that the communication via one link serves as backup communication for the communication via the other link. More specifically, the AP 102 can transmit the same data to the STA 103 via the first link in the first frequency channel and via the second link in the second frequency channel. In this case, for example, even if an error occurs in the communication via the first link, the STA 103 is able to receive the data transmitted from the AP 102 because the same data is transmitted via the second link. Alternatively, the AP 102 and the STA 103 can adaptively use the links depending on the type of frame or data to be communicated. For example, the AP 102 can transmit a management frame via the first link, and transmit a data frame containing data via the second link. Note that the management frame specifically refers to a beacon frame, a probe request frame / response frame, or an association request frame / response frame.

[0033] In addition to these frames, a disassociation frame, an authentication frame, a de-authentication frame, and an action frame are also referred to as management frames. A beacon frame is a frame for providing network information. A probe request frame is a frame for requesting network information, and a probe response frame is a frame for providing network information in response to the probe request frame. An association request frame is a frame for requesting connection, and an association response frame is a frame indicating permission of connection or an error, and the like, in response to the association request frame. A disassociation frame is a frame for disconnecting connection. An authentication frame is a frame for authenticating the counterpart device, and a de-authentication frame is a frame for interrupting authentication of the counterpart device and disconnecting connection. An action frame is a frame for performing an additional function other than the above-described functions. The AP 102 and the STA 103 transmit and receive the management frames according to the IEEE 802.11 series standards. Alternatively, when the AP 102 transmits data related to a captured image, for example, meta information indicating a date, a camera parameter (an aperture value, a shutter speed, and the like), and / or position information, and the like can be transmitted via the first link, and pixel information can be transmitted via the second link.

[0034] The AP 102 and the STA 103 are capable of MIMO (Multiple Input Multiple Output) communication. In this case, the AP 102 and the STA 103 each have a plurality of antennas, and one of the AP 102 and the STA 103 transmits different signals from each antenna using the same frequency channel. The receiving device receives all signals arriving via a plurality of streams using a plurality of antennas at the same time, and separates and decodes the signals of each stream.

[0035] The MIMO communication is performed in the above-described manner, which enables the AP 102 and the STA 103 to communicate more data in the same period of time than when the MIMO communication is not performed. When the AP 102 and the STA 103 perform multi-link communication, the MIMO communication can be performed using only a part of the links.

[0036] In order to broadcast network information, the AP 102 can transmit a FILS discovery frame and / or an unsolicited probe response frame in addition to a beacon frame. FILS is an abbreviation for Fast Initial Link Setup.

[0037] The AP 102 can incorporate information about a plurality of APs used by the AP 102 into a RNR (Reduced Neighbor Report) element in the FILS discovery frame. More specifically, the RNR element can include information about the operating class, channel information, and beacon frame transmission timing of each AP. When the AP 102 is in a multi-link operation, the AP 102 can incorporate information about a plurality of APs used in the multi-link operation into the FILS discovery frame. Note that the FILS discovery frame contains less information than the beacon frame.

[0038] The AP 102 can incorporate information similar to that included in the normal probe response frame into the unsolicited probe response frame. Note that unlike the normal probe response frame, the unsolicited probe response frame is a frame autonomously transmitted by the AP 102 at a predetermined time interval. The AP 102 supporting multi-link communication can incorporate a RNR element including information about the multi-link of the AP 102 into the unsolicited probe response frame. The RNR element includes information common to a plurality of links established by the AP 102.

[0039] The IEEE 802.11ax standard stipulates that when an AP operates in the 6 GHz band, the AP can transmit the FILS discovery frame and / or the unsolicited probe response frame at an interval of 20 TUs. Note that TU is an abbreviation of Time Unit, and 1 TU corresponds to 1 ms. In this case, the AP transmits the FILS discovery frame and / or the unsolicited probe response frame at an interval shorter than the beacon frame transmission interval of 100 TUs.

[0040] When the AP 102 establishes a plurality of links including the 6 GHz band and performs multi-link communication, if frames containing information about the multi-link communication are transmitted at an interval of 20 TUs, a decrease in communication throughput can occur. To cope with such a situation, according to the present embodiment, the AP 102 appropriately sets the transmission interval of these frames based on whether or not multi-link communication is being performed, thereby suppressing a decrease in communication throughput.

[0041] Although it is assumed above that the AP 102 and the STA 103 support the IEEE 802.11be standard, the AP 102 and the STA 103 can also support at least one of legacy standards prior to the IEEE 802.11be standard. The legacy standards include IEEE 802.11a / b / g / n / ac / ax standards. In the present embodiment, at least one of the IEEE 802.11a / b / g / n / ac / ax / be standards is referred to as an IEEE 802.11 series standard. In addition to the IEEE 802.11 series standards, other communication standards such as Bluetooth (registered trademark), NFC, UWB, Zigbee, and / or MBOA, and the like can also be supported. UWB is an abbreviation for Ultra Wide Band, and MBOA is an abbreviation for Multi Band OFDM Alliance. OFDM is an abbreviation for Orthogonal Frequency Division Multiplexing. NFC is an abbreviation for Near Field Communication. UWB includes wireless USB, wireless 1394, Winet, and the like. A communication standard for wired communication such as a wired LAN can also be supported.

[0042] Specific examples of the AP 102 include, but are not limited to, a wireless LAN router and a PC. Any communication device can be used as the AP 102 as long as the communication device can perform multi-link communication with other communication devices. The AP 102 can be an information processing device such as a wireless chip capable of performing wireless communication according to the IEEE 802.11be standard. Specific examples of the STA 103 include, but are not limited to, a camera, a tablet device, a smart phone, a PC, a mobile phone, a video camera, and the like. Any communication device can be used as the STA 103 as long as the communication device can perform multi-link communication with other communication devices. The STA 103 can be an information processing device such as a wireless chip capable of performing wireless communication according to the IEEE 802.11be standard. Figure 1 The illustrated network includes one AP and one STA, but the number of APs and the number of STAs are not limited to one. Note that an information processing device such as a wireless chip has an antenna for transmitting a generated signal.

[0043] Although it is assumed in this embodiment that the AP 102 is an access point and the STA 103 is a station, this is by way of example. For example, both the AP 102 and the STA 103 can be stations. In this case, although the AP 102 is a station, the AP 102 operates as a device responsible for configuring a wireless network for establishing a link with the STA 103.

[0044] Figure 2 An example of a hardware configuration of the AP 102 is shown. The AP 102 includes a storage unit 201, a control unit 202, a functional unit 203, an input unit 204, an output unit 205, a communication unit 206, and an antenna 207.

[0045] The storage unit 201 includes one or a plurality of memories such as a ROM and / or a RAM, and functions to store a computer program for performing various operations described later, and various information such as a communication parameter for wireless communication. The ROM is an abbreviation for Read Only Memory, and the RAM is an abbreviation for Random Access Memory. Examples of the storage unit 201 include, in addition to a memory such as a ROM or a RAM, a storage medium such as a floppy disk, a hard disk, an optical disk, a magneto-optical disk, a CD-ROM, a CD-R, a magnetic tape, a nonvolatile memory card, and a DVD. The storage unit 201 can include a plurality of memories and the like.

[0046] The control unit 202 includes, for example, one or a plurality of processors such as a CPU and an MPU, and controls the entire AP 102 by executing a computer program stored in the storage unit 201. The control unit 202 can control the entire AP 102 in cooperation with the computer program and an OS (Operating System) stored in the storage unit 201. The control unit 202 generates data or a signal (a wireless frame) to be transmitted in communication with other communication devices. Note that the CPU is an abbreviation for Central Processing Unit, and the MPU is an abbreviation for Micro Processing Unit. The control unit 202 can include a plurality of processors such as a multi-core processor, and can control the entire AP 102 by using a plurality of processors.

[0047] The control unit 202 controls the functional unit 203 to perform a predetermined process such as wireless communication, imaging, printing, or projection. The functional unit 203 is a hardware unit with which the AP 102 performs a predetermined process.

[0048] The input unit 204 accepts various operations by the user. The output unit 205 provides various outputs to the user via a monitor screen and / or a speaker. The output of the output unit 205 can be provided by displaying information on the monitor screen, outputting audio information via the speaker, or outputting vibration, and the like. Note that the input unit 204 and the output unit 205 can be integrated in one module as in a touch panel. The input unit 204 and the output unit 205 can each be integrated with or separated from the AP 102.

[0049] The communication unit 206 controls wireless communication according to the IEEE 802.11be standard. The communication unit 206 can control wireless communication according to other IEEE 802.11 series standards in addition to the IEEE 802.11be standard, or can control wired communication such as wired LAN. The communication unit 206 controls the antenna 207 to transmit and receive a signal generated by the control unit 202 for wireless communication. The AP 102 can include a plurality of communication units 206. When a plurality of links are established in multi-link communication, the AP 102 including a plurality of communication units 206 establishes at least one link for each communication unit 206. Alternatively, the AP 102 can establish a plurality of links using one communication unit 206. In this case, the communication unit 206 performs communication via a plurality of links by switching frequency channels in a time-division manner. Note that in the case where the AP 102 supports the NFC standard and / or the Bluetooth standard, and the like in addition to the IEEE 802.11be standard, wireless communication can be controlled according to these communication standards. In the case where the AP 102 is capable of performing wireless communication according to a plurality of communication standards, a communication unit and an antenna can be separately provided for each communication standard. The AP 102 communicates data such as image data, document data, and / or video data with the STA 103 via the communication unit 206. The antenna 207 can be separately provided from the communication unit 206, or can be integrated with the communication unit 206 in a single module.

[0050] The antenna 207 is an antenna capable of communication in the 2.4 GHz band, the 5 GHz band, and the 6 GHz band. Although it is assumed above in the present embodiment that the AP 102 has one antenna, the AP 102 can have a plurality of antennas for each frequency band. In the case where the AP 102 has a plurality of antennas, the AP 102 can have a plurality of communication units 206 corresponding to each antenna.

[0051] Note that the STA 103 has a hardware configuration similar to that of the AP 102.

[0052] Figure 3An example of a functional configuration of the AP 102 is shown. The AP 102 includes a multi-link control unit 301, a FILS discovery frame generation unit 302, and an unsolicited probe response frame generation unit 303. The AP 102 also includes a frame transmission interval control unit 304, a beacon frame generation unit 305, and a frame transmission / reception unit 306.

[0053] The multi-link control unit 301 controls whether the AP 102 performs multi-link communication or single-link communication. Single-link communication is communication performed so that the AP 102 establishes only a single link and performs communication using the single link. The determination as to whether the AP 102 performs multi-link communication can be set by a user, or can be determined by the AP 102 according to a channel usage state.

[0054] The FILS discovery frame generation unit 302 generates a FILS discovery frame according to the multi-link communication of the AP 102 or the frequency band used by the AP 102.

[0055] The unsolicited probe response frame generation unit 303 generates an unsolicited probe response frame according to the multi-link communication of the AP 102 or the frequency band used by the AP 102.

[0056] The frame transmission interval control unit 304 controls the transmission intervals of the beacon frame, the FILS discovery frame, and the unsolicited probe response frame transmitted by the AP 102. The beacon frame is transmitted at an interval of 100 TUs, and the FILS discovery frame and the unsolicited probe response frame are transmitted at an interval shorter than 100 TUs.

[0057] The beacon frame generation unit 305 generates a beacon frame. The beacon frame includes an unsolicited probe responses active subfield, which is a flag indicating whether to transmit an unsolicited probe response frame. The unsolicited probe responses active subfield is included in a Neighbor Report element and an RNR element. The beacon frame can include an RNR element including information related to the multi-link communication performed by the AP 102.

[0058] The frame transmission / reception unit 306 controls the transmission / reception of management frames such as the beacon frame, the FILS discovery frame, and the unsolicited probe response frame, and controls the transmission / reception of control frames and data frames.

[0059] Figure 4 is a sequence diagram showing processing performed when the AP 102 communicates with the STA 103 via a single link. In Figure 4In the example shown, AP 102 performs single-link communication. Processing of this sequence begins when AP 102 is powered on. Alternatively, this processing can begin in response to a user instruction for AP 102 to perform single-link communication. AP 102 operates AP1 and performs single-link communication with STA103. Note that AP1 operates in the 6GHz band.

[0060] AP 102 sends a beacon frame containing information related to AP1 (S401). Next, since AP 102 is communicating in the 6GHz band, AP 102 sends an unsolicited probe response frame (S402). AP 102 sends unsolicited probe response frames at 20TU intervals.

[0061] When 100TUs have passed since the last beacon frame transmission, AP 102 transmits a beacon frame again (S403).

[0062] As described above, in the case of AP 102 performing single-link communication in the 6GHz band, AP 102 sends unsolicited probe response frames at 20TU intervals between adjacent transmissions of beacon frames. These unsolicited probe response frames do not include information related to the multiple APs used for multi-link communication, thus reducing communication overhead. Therefore, AP 102 sends unsolicited probe response frames at short intervals of 20TU. Although in Figure 4 In the process, it is assumed that AP 102 sends an unsolicited probe response frame, but instead of at least one unsolicited probe response frame, it may send a FILS discovery frame.

[0063] Figure 5 This is a sequence diagram illustrating the processes performed when AP 102 communicates with STA 103 via multiple links. Figure 5 In the example shown, AP 102 performs multilink communication. Processing of this sequence begins when AP 102 is powered on. Alternatively, this processing can begin in response to a user instruction for AP 102 to perform multilink communication. AP 102 operates AP1 and AP2 to perform multilink communication with STA 103. Note that AP1 and AP2 operate using different frequency channels in the 6 GHz band.

[0064] The AP 102 transmits a beacon frame using the AP2 (S501). The beacon frame transmitted in this step includes an RNR element including information common to the links established by the AP1 and the AP2. Next, the AP 102 transmits an unsolicited probe response frame including the RNR element using the AP2 (S502). The AP 102 transmits the unsolicited probe response frame at an interval of 50 TU which is longer than 20 TU. When 100 TU has elapsed from the previous transmission of the beacon frame, the AP 102 transmits the beacon frame again using the AP2 (S503). In this sequence, the AP 102 uses the AP2. However, this sequence can be performed using the AP1.

[0065] As described above, in a case where the AP 102 performs the multi-link communication, the AP 102 transmits the unsolicited probe response frame at an interval of 50 TU which is longer than 20 TU between the adjacent transmissions of the beacon frame. The unsolicited probe response frame transmitted here includes information on the plurality of APs for the multi-link communication, and this causes an increase in communication overhead. Therefore, the AP 102 transmits the unsolicited probe response frame at an interval of 50 TU which is longer than 20 TU. In this sequence, the transmission interval of the unsolicited probe response frame is set to 50 TU, but the interval is not limited to this, and can be set to an arbitrary value which is longer than 20 TU. Although the AP 102 transmits the unsolicited probe response frame in the processing of Figure 5 Instead of at least one unsolicited probe response frame, a FILS discovery frame can be transmitted.

[0066] Figure 6 is a sequence diagram illustrating another example of the processing performed when the AP 102 communicates with the STA 103 via the plurality of links. In this example, the AP 102 performs the multi-link communication. Figure 6 In the example shown, the AP 102 performs the multi-link communication. The processing of this sequence starts when the power of the AP 102 is turned on. Alternatively, the processing can start in response to a user instructing the AP 102 to perform the multi-link communication. The AP 102 operates the AP1 and the AP2 to perform the multi-link communication with the STA 103. Note that the AP1 and the AP2 operate in the 6 GHz band using different frequency channels from each other.

[0067] The AP 102 transmits a beacon frame using the AP2 (S601). The beacon frame transmitted in this step includes an RNR element including information common to the links established by the AP1 and the AP2. When 100 TU has elapsed from the previous transmission of the beacon frame, the AP 102 transmits the beacon frame using the AP2 again (S602). In this sequence, the AP 102 uses the AP2. However, this sequence can be performed using the AP1. In the example of this sequence, the AP 102 does not transmit an unsolicited probe response frame including an RNR element nor a FILS discovery frame including an RNR element, but transmits the beacon frame at intervals of 100 TU.

[0068] As described above, when the AP 102 performs the multi-link communication, the AP 102 does not transmit the unsolicited probe response frame nor the FILS discovery frame between the adjacent transmissions of the beacon frame. This can reduce the overhead of the communication.

[0069] Figure 7 is a flowchart showing the processing performed by the control unit 202 by reading and executing the computer program stored in the storage unit 201 when the AP 102 performs the multi-link communication or the single-link communication.

[0070] This flowchart starts when the power of the AP 102 is turned on. Alternatively, this processing can start in response to the user instructing the AP 102 to start the communication.

[0071] First, the AP 102 determines whether its operation mode is the multi-link operation mode or the single-link operation mode (S701). Whether the AP 102 performs the multi-link communication or the single-link communication is determined by the user. Alternatively, the AP 102 can autonomously determine whether to perform the multi-link communication or the single-link communication based on the status of the frequency channel and the frequency band and / or the size of the data to be communicated, and the like.

[0072] Next, the AP 102 determines whether the AP 102 has received an AP stop instruction (S702). More specifically, the AP 102 determines whether the user has instructed the AP 102 to stop its operation as an AP. When the AP 102 is instructed to stop, the AP 102 determines "Yes" in this step, and stops the operation as an AP and ends the processing of this flowchart. In the case where the AP 102 is not instructed to stop, the AP 102 determines "No" in this step, and performs the processing in S703.

[0073] The AP 102 determines whether the AP 102 is performing a multi-link communication operation (S703). In a case where the AP 102 is performing a multi-link communication, the AP 102 determines "Yes" in this step, and proceeds to the processing in S704. On the other hand, in a case where the AP 102 is performing a single-link communication, the AP 102 determines "No" in this step, and proceeds to the processing in S705.

[0074] The AP 102 performs the beacon frame transmission processing in a multi-link operation (S704). Details of this step will be described later with reference to Figure 9 or Figure 10 Details of this step will be described later with reference to

[0075] In a case where the determination in S703 is "No", the AP 102 performs the beacon frame transmission processing in a single-link operation (S705). Details of this step will be described later with reference to Figure 8 Details of this step will be described later with reference to

[0076] After the AP 102 performs the processing in S704 or the processing in S705, the AP 102 determines whether an instruction to change the operation of the multi-link communication has been received (S706). More specifically, the AP 102 determines whether the AP 102 has received an instruction to perform a multi-link communication from a user. Alternatively or additionally, the AP 102 can determine whether the AP 102 has received an instruction to change the frequency channel, the frequency band, the mode, and / or the number of links, and the like of the multi-link communication from a user. Instead of receiving these change instructions from a user, the AP 102 can autonomously make a change based on the state of the communication being performed and / or the state of the frequency channel, and the like. When the AP 102 determines that the AP 102 has received a change instruction or when the AP 102 autonomously determines to make a change, the AP 102 determines "Yes" in this step, and proceeds to the processing in S701 again. On the other hand, when the AP 102 determines that the AP 102 has not received a change instruction or when the AP 102 autonomously determines not to make a change, the AP 102 determines "No" in this step, and proceeds to the processing in S702.

[0077] As shown in Figure 7 Details of this step will be described later with reference to

[0078] Note that, in this flowchart and in the flowchart shown in Figure 8 to Figure 10 only the transmission processing of the beacon frame, the unsolicited probe response frame, and the FILS discovery frame is described, and other processing is not shown, but the processing not shown in these flowcharts can be performed. The AP 102 can perform the processing not shown in these flowcharts in addition to the transmission processing of the beacon frame, the unsolicited probe response frame, and the FILS discovery frame. Figure 7 to Figure 10The illustrated steps are performed in parallel or between the steps, processes such as transmission and reception of data frames, transmission and reception of other management frames or control frames, and the like.

[0079] Figure 8 is a flowchart showing the processing performed by the control unit 202 by reading and executing the computer program stored in the storage unit 201 when the AP 102 transmits a beacon frame in single-link communication.

[0080] The processing of this flowchart starts in response to the AP 102 starting Figure 7 the processing in S705.

[0081] First, the AP 102 incorporates a neighbor report element or RNR element in which the unsolicited probe response activity subfield is set to 1 into the beacon frame (S801). This enables the AP 102 to notify that unsolicited probe response frames will be transmitted.

[0082] Next, the AP 102 sets the transmission interval for transmitting the unsolicited probe response frame to 20 TU or less (S802). Since the AP 102 is performing single-link communication, information on a plurality of APs related to multi-link communication is not included in the unsolicited probe response frame. Therefore, even when the transmission interval of the unsolicited probe response frame is set to 20 TU or less, the communication overhead is small.

[0083] Next, the AP 102 determines whether or not the transmission interval of the unsolicited probe response frame has elapsed since the previous transmission of the beacon frame or the unsolicited probe response frame (S803). In a case where the transmission interval has not elapsed, the AP 102 determines "No" in this step, and proceeds to the processing in S807. In a case where the transmission interval has elapsed, the AP 102 determines "Yes" in this step, and proceeds to the processing in S804. The AP 102 determines whether or not the beacon frame transmission interval has elapsed since the previous transmission of the beacon frame (S807). Note that the beacon frame transmission interval of the AP 102 is preset to 100 TU in the AP 102. Alternatively, any transmission interval can be set by a user. In a case where the beacon transmission interval has elapsed, the AP 102 determines "Yes" in this step, and proceeds to the processing in S806. In a case where the beacon transmission interval has not elapsed, the AP 102 determines "No" in this step, and proceeds to the processing in S803 again.

[0084] The AP 102 determines whether or not a beacon frame transmission interval has passed since the previous transmission of the beacon frame (S804). In the case where the beacon transmission interval has passed, the AP 102 determines "Yes" in this step, and proceeds to the processing in S806. In the case where the beacon transmission interval has not passed, the AP 102 determines "No" in this step, and proceeds to the processing in S805.

[0085] The AP 102 transmits the unsolicited probe response frame (S805). After the AP 102 performs the processing in S805, the AP 102 again performs the determination in S803.

[0086] On the other hand, in the case where the determination in S804 is "Yes", the AP 102 transmits the beacon frame (S806). After the AP 102 performs the processing in this step, the AP 102 ends the processing of this flowchart.

[0087] Although the unsolicited probe response frame is transmitted in the processing of Figure 8 , this is by way of example and not limitation. For example, a FILS discovery frame can be transmitted. In this case, the AP 102 skips the processing in S801.

[0088] Figure 9 This flowchart shows the processing performed by the control unit 202 by reading and executing the computer program stored in the storage unit 201, when the AP 102 transmits the beacon frame in multi-link communication.

[0089] The processing of this flowchart starts in response to the AP 102 starting Figure 7 the processing in S704.

[0090] The processing in S901 is similar to the processing in S801 of Figure 8 .

[0091] Next, the AP 102 determines whether the beacon frame size is larger than a predetermined threshold in the case where the beacon frame includes an RNR element including information common to a plurality of links used in multi-link communication (S902), or determines whether the number of established links is larger than a predetermined threshold. In the case where it is determined that the beacon frame size is larger than the predetermined threshold, or it is determined that the number of established links is larger than the predetermined threshold, the AP 102 determines "Yes" in this step, and proceeds to the processing in S903. On the other hand, in the case where it is determined that the beacon frame size is equal to or smaller than the predetermined threshold, or it is determined that the number of established links is equal to or smaller than the predetermined threshold, the AP 102 determines "No" in this step, and proceeds to the processing in S904. In this step, the determination of the beacon frame size or the number of links can be selected by a user, or can be preset in the AP 102. Alternatively, the AP 102 can make both determinations. In this case, the AP 102 can determine "Yes" in this step in the case where at least one of the determination results is "Yes". Note that both the predetermined threshold of the beacon frame and the predetermined threshold of the number of links can be preset in the AP 102, or can be set by a user.

[0092] The AP 102 sets the transmission interval for transmitting the unsolicited probe response frame to a value larger than 20 TU (S903). The unsolicited probe response frame to be transmitted includes an RNR element including information common to a plurality of links used in multi-link communication.

[0093] On the other hand, in the case where it is determined "No" in S902, the AP 102 sets the transmission interval for transmitting the unsolicited probe response frame to a value equal to or smaller than 20 TU (S904). The unsolicited probe response frame to be transmitted includes an RNR element including information common to a plurality of links used in multi-link communication.

[0094] The processing in S905 to S909 is similar to the processing in S803 to S807 in Figure 8 .

[0095] As shown in Figure 9 , in the case where the beacon frame size is equal to or larger than a predetermined threshold, or the number of links is equal to or larger than a predetermined threshold, the AP 102 sets the transmission interval for transmitting the unsolicited probe response frame to a value larger than 20 TU. This makes it possible to reduce the frequency of transmitting the unsolicited probe response frame including the RNR element including information common to a plurality of links used in multi-link communication, thereby reducing the communication overhead.

[0096] Although in Figure 9transmit an unrequested probe response frame, but this is by way of example and not limitation. For example, a FILS discovery frame can be transmitted. In this case, the AP 102 skips the processing in S901.

[0097] Alternatively, the determination in S902 can be skipped, and the processing in S903 can be performed. In this case, in response to performing the multi-link communication, the AP 102 sets the transmission interval for transmitting an unrequested probe response frame to a value greater than 20 TU.

[0098] Figure 10 is a flowchart showing processing different from that shown in Figure 9 The processing is also performed by the control unit 202 by reading and executing the computer program stored in the storage unit 201 when the AP 102 transmits a beacon frame in the multi-link communication. In Figure 10 In the processing shown in the flowchart of

[0099] In response to the AP 102 starting Figure 7 the processing in S704 in

[0100] First, the AP 102 incorporates a neighbor report element or RNR element in which an unrequested probe response active subfield is set to 0 into a beacon frame (S1001). This enables the AP 102 to notify that an unrequested probe response frame will not be transmitted.

[0101] In S1002, the AP 102 performs processing similar to that in S804 in Figure 8 In the case where the determination in S1002 is "No", the AP 102 performs the processing in S1002 again. On the other hand, in the case where the determination in S1002 is "Yes", the AP 102 performs the processing in S1003.

[0102] In S1003, the AP 102 performs processing similar to that in S806 in Figure 8

[0103] Therefore, as described above with reference to Figure 10 the unrequested probe response frame is not transmitted when the multi-link communication is being performed, thereby suppressing the communication overhead.

[0104] Note that instead of suppressing the transmission of the unrequested probe response frame, the AP 102 can suppress the transmission of a FILS discovery frame. In this case, the AP 102 skips the processing in S1001 in this flow.

[0105] The AP 102 can be capable of selecting​Figure 9 The processes shown and Figure 10 The processes shown can be performed by the AP 102 as a mode of the device, or can be a device that is capable of performing only one of these processes.

[0106] Figure 7 to Figure 10 The flow shown in the flowchart in FIG. 10 can be performed in the case where the AP 102 operates only in the 6 GHz band, and can not be performed in the case where the AP 102 operates in the 2.4 GHz band and / or the 5 GHz band. Alternatively, the AP 102 can perform Figure 7 to Figure 10 The processes shown.

[0107] Figure 7 to Figure 10 At least a part or all of the flowchart of the AP 102 shown can be implemented by hardware. When implemented using hardware, for example, a dedicated circuit can be generated on an FPGA using, for example, a specific compiler based on a computer program for implementing the steps, and the resulting dedicated circuit can be used. FPGA is an abbreviation for Field Programmable Gate Array. Alternatively, a gate array circuit can be formed in a similar manner to the FPGA, so as to achieve implementation using hardware. Alternatively, implementation can be achieved using an ASIC.

[0108] The present application can also be implemented by providing a program for implementing one or more functions of the embodiments to a system or a device via a network or a storage medium, and reading out and executing the program by one or more processors arranged in the system or the device. The present application can also be implemented by a circuit (for example, an ASIC) for implementing one or more functions.

[0109] The present application is not limited to the above-described embodiments, but various changes and modifications can be made without departing from the spirit and scope of the present application. Therefore, the appended claims are added so as to disclose the scope of the present application.

[0110] This application claims priority to Japanese Patent Application No. 2020-147490, filed September 2, 2020, the entire contents of which are incorporated herein by reference.

Claims

1. A communication device, comprising: The establishment unit is configured to establish multiple links with other communication devices via multiple different channels; as well as The control unit is configured to control the transmission of FILS discovery frames and / or unsolicited probe response frames at intervals greater than 20 TU (time units) when communication is being conducted using multiple links established by the establishment unit, or to not transmit FILS discovery frames and / or unsolicited probe response frames, and to transmit FILS discovery frames and / or unsolicited probe response frames at intervals of 20 TU or less when communication is not being conducted using multiple links established by the establishment unit.

2. The communication device of claim 1, further comprising a transmitting unit configured to transmit a beacon frame when communicating using multiple links established by the establishing unit and without transmitting FILS discovery frames and / or unsolicited probe response frames, the beacon frame including an unsolicited probe response activity subfield set to a value of 0.

3. The communication device according to claim 1, further comprising: The sending unit is configured to send a beacon frame, which includes an unsolicited probe response activity subfield set to a value of 1, when communicating using multiple links established by the establishment unit and sending FILS discovery frames and / or unsolicited probe response frames at intervals greater than 20 TUs.

4. The communication device according to claim 3 further includes a first determining unit, the first determining unit being configured to determine whether the size of the beacon frame sent by the sending unit is greater than a predetermined threshold when multiple links established by the establishing unit are being used for communication. in, The control unit performs control such that when the first determination unit determines that the size of the beacon frame is greater than the predetermined threshold, FILS discovery frames and / or unsolicited probe response frames are sent at intervals greater than 20 TUs; and when the first determination unit determines that the size of the beacon frame is equal to or less than the predetermined threshold, FILS discovery frames and / or unsolicited probe response frames are sent at intervals equal to or less than 20 TUs.

5. The communication device according to claim 3 further includes a second determining unit, the second determining unit being configured to determine whether the number of links established by the establishing unit is greater than a predetermined threshold when multiple links established by the establishing unit are being used for communication. in, The control unit performs control such that when the second determination unit determines that the number of links is greater than the predetermined threshold, FILS discovery frames and / or unsolicited probe response frames are sent at intervals greater than 20 TUs; and when the second determination unit determines that the number of links is equal to or less than the predetermined threshold, FILS discovery frames and / or unsolicited probe response frames are sent at intervals equal to or less than 20 TUs.

6. The communication device according to claim 1, wherein, When multiple links established by the establishment unit are being used for communication, the FILS discovery frame includes information related to multiple access points (APs) used by the communication device.

7. The communication device according to claim 1, wherein, When multiple links established by the establishment unit are being used for communication, the unsolicited probe response frame includes a reduced neighbor report element, i.e., an RNR element, which includes information common to the multiple links.

8. The communication device according to claim 1, wherein, The communication device operates only in the 6GHz band.

9. The communication device according to claim 1, wherein, Communication using the multiple links is multi-link communication according to the IEEE 802.11be standard.

10. A method for controlling a communication device, comprising: Establish multiple links with other communication devices via multiple different channels; as well as Control is implemented such that when multiple established links are being used for communication, FILS discovery frames and / or unsolicited probe response frames are sent at intervals greater than 20 TU (time units), or no FILS discovery frames and / or unsolicited probe response frames are sent; and when multiple established links are not being used for communication, FILS discovery frames and / or unsolicited probe response frames are sent at intervals of 20 TU or less.

11. A computer-readable storage medium storing a program configured to cause a computer to act as various units of the communication device according to claim 1.

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