Communication device, relay method, communication method, and program

Abstract

This communication device, operating as a station device conforming to the IEEE 802.11 standard series, has a function as a first station device that relays communication between an access point device being connected and one or more other station devices connected to the access point device. The communication device receives, from the access point device, a prescribed frame including specific information identifying a second station device that has a prescribed capability for communicating with the access point device via the relay of the first station device among the one or more other station devices. A relay means executes the relay for communication between the second station device identified by the specific information and the access point device.

Description

Communication device, relay method, communication method and program

[0001] The present invention relates to a technique for relaying data frames in communication between an access point and a station.

[0002] In recent years, with the increase in the amount of data being communicated, the development of communication technologies such as wireless local area networks (LANs) has been progressing. The IEEE (Institute of Electrical and Electronic Engineers) 802.11 standard series is known as the main communication standard for wireless LANs. The IEEE 802.11 standard series includes IEEE 802.11a / b / g / n / ac / ax / be standards, etc.

[0003] Successor standards to the IEEE 802.11be standard are being studied with the aim of further improving throughput and expanding communication range. For example, in addition to communication methods in which direct communication is performed between an access point (hereinafter, AP) and a station (hereinafter, STA), relay communication methods using a relay communication device are being studied. Relay communication may also be called relay communication. In relay communication, a relay communication device, or STA, receives a data frame transmitted by an AP and transmits the data frame to another STA, or receives a data frame transmitted by another STA and transmits the data frame to the AP. For example, Patent Document 1 describes the use of a trigger frame defined in the IEEE 802.11 standard series for controlling relay communication.

[0004] Japanese Patent Application Laid-Open No. 2021-72638

[0005] The present invention provides a technique for efficiently identifying a device capable of performing relay communication when relay communication is used in communication between an access point and a station.

[0006] A communication device that operates as a station device conforming to the IEEE 802.11 standard series, comprising: a relay means having the function of a first station device that relays communications between a connected access point device and one or more other station devices connected to the access point device; and a receiving means that receives from the access point device a predetermined frame including specific information that identifies a second station device among the one or more other station devices that has a specific capability to communicate with the access point device through relaying by the first station device, wherein the relay means relays communications between the second station device identified by the specific information and the access point device.

[0007] According to the present invention, when relay communication is used in communication between an access point and a station, it is possible to efficiently identify a device capable of performing relay communication.

[0008] Other features and advantages of the present invention will become apparent from the following description taken in conjunction with the accompanying drawings, in which the same or similar elements are designated by the same reference numerals.

[0009] The accompanying drawings are incorporated into and constitute a part of the specification, illustrate embodiments of the present invention, and together with the description are used to explain the principles of the present invention. FIG. 1 is a diagram illustrating an example of the configuration of a wireless communication system. FIG. 2 is a diagram illustrating an example of the hardware configuration of a communication device. FIG. 3 is a diagram illustrating an example of the functional configuration of an AP. FIG. 4 is a diagram illustrating an example of the functional configuration of a STA. FIG. 5 is a diagram illustrating an example of frame exchange performed between communication devices. FIG. 6 is a diagram illustrating an example of a UHR Capability element. FIG. 7A is a diagram illustrating an example of an Action frame. FIG. 7B is a diagram illustrating an example of an Action frame. FIG. 8 is a diagram illustrating an example of a UHR Capability element. FIG. 9 is an example of a processing flow executed by an AP. FIG. 10 is an example of a processing flow executed by a STA. FIG. 11 is a diagram illustrating an example of frame exchange performed between communication devices. FIG. 12 is a diagram illustrating an example of frame exchange performed between communication devices. FIG. 13 is a diagram illustrating an example of frame exchange performed between communication devices.

[0010] Hereinafter, embodiments will be described in detail with reference to the accompanying drawings. Note that the following embodiments do not limit the scope of the invention claimed. Although multiple features are described in the embodiments, not all of these multiple features are necessarily essential to the invention, and multiple features may be combined arbitrarily. Furthermore, in the accompanying drawings, the same reference numerals are used to designate the same or similar components, and redundant explanations will be omitted.

[0011] (System Configuration) Fig. 1 shows an example configuration of a wireless communication system according to this embodiment. The wireless communication system includes, for example, an access point (AP) 101 and stations (STA) 111 and 112. In this embodiment, the STAs 111 and 112 may be collectively referred to as STA 110. The AP 101 and STA 110 may be collectively referred to as communication device 100. The AP 101 and STA 110 are each communication devices capable of performing wireless communication in accordance with the IEEE 802.11 standard series. IEEE stands for Institute of Electrical and Electronics Engineers. Fig. 1 shows a configuration in which the STAs 111 and 112 participate in a network 131 established by the AP 101. The network 131 may also be referred to as a Basic Service Set (BSS). When the STA 110 joins the network 131, it is sometimes said that the STA 110 belongs to the network 131 (or the AP 101). The AP 101 and the STA 111 are connected using a wireless channel 121. The AP 101 and the STA 112 are connected using a wireless channel 122. The STA 111 and the STA 112 may also be connected using a wireless channel 123. In this example, it is assumed that the STA 111 and the STA 112 are located within the communication range of the network 131 established by the AP 101. It is assumed that the geographical distance between the AP 101 and the STA 111 is longer than both the distance between the AP 101 and the STA 112 and the distance between the STA 111 and the STA 112. For example, it is assumed that the STA 112 is located between the AP 101 and the STA 111. 1 shows a configuration in which one AP 101 and two STAs 110 exist, multiple APs may exist, or three or more STAs may exist. In this case, multiple STAs may be connected to one AP, or one STA may be connected to multiple APs.

[0012] In this embodiment, the communication device 100 is configured to be able to execute a communication method compliant with a successor standard to the IEEE 802.11 standard. For example, the communication device 100 is configured to be able to execute a communication method compliant with the IEEE 802.11bn standard. The IEEE 802.11bn standard is a successor standard to the IEEE 802.11be standard, which targets a maximum transmission speed of 46.08 Gbps (Giga bit per second). The main features of the IEEE 802.11bn standard are its functions of realizing highly reliable communication, low latency communication, and improved throughput when communication traffic is congested. The IEEE 802.11bn standard may also be referred to as the UHR standard. UHR is an abbreviation for Ultra High Reliability. The communication device 100 may perform a communication method compliant with a successor standard to the IEEE 802.11bn standard. The communication device 100 may also support at least one legacy standard that predates the IEEE 802.11bn standard. Examples of legacy standards include the IEEE 802.11a / b / g / n / ac / ax / be standards. The communication device 100 may also support other communication standards such as Bluetooth (registered trademark), NFC, UWB, ZigBee, and MBOA. UWB stands for Ultra Wide Band, and MBOA stands for Multi Band OFDM Alliance. NFC stands for Near Field Communication. UWB includes wireless USB, wireless 1394, WiNET, etc. The communication device 100 may also be compatible with communication standards such as wired LAN. The AP 101 may be, for example, a wireless LAN router or a personal computer (PC), but is not limited to these. The AP 101 may be an information processing device such as a wireless chip capable of performing wireless communication compatible with the IEEE 802.11bn standard, etc. The STA 110 may be, for example, a camera, a tablet, a smartphone, a PC, a mobile phone, a video camera, a headset, etc., but is not limited to these. The STA 110 may be an information processing device such as a wireless chip capable of performing wireless communication compatible with the IEEE 802.11bn standard, etc. The STA 110 may also be a communication device having an AP function.

[0013] The communication device 100 may communicate using radio signals in frequency bands such as the 2.4 GHz band, the 3.6 GHz band, the 5 GHz band, the 6 GHz band, and the 45 GHz band and 60 GHz band known as millimeter waves. The frequency bands used by the communication device 100 are not limited to these and may be, for example, the Sub1 GHz band. The communication device 100 may also communicate using bandwidths of 20 MHz, 40 MHz, 80 MHz, 160 MHz, 320 MHz, 540 MHz, 640 MHz, 1080 MHz, and 2160 MHz. The bandwidths used by the communication device 100 are not limited to these and may be, for example, 240 MHz, 4 MHz, etc.

[0014] The IEEE 802.11 series of standards specifies a function for increasing communication speed by performing multi-user (MU) communication, in which an AP multiplexes wireless resources to communicate simultaneously with multiple STAs. For example, an AP can communicate with multiple STAs in parallel using OFDMA communication. OFDMA stands for Orthogonal Frequency Division Multiple Access. In OFDMA communication, portions of a divided frequency band (Resource Units, RUs) are allocated to communications between the AP and each STA so that they do not overlap. In OFDMA communication, the carrier waves used in communications between the AP and each STA are orthogonal on the frequency axis. This configuration utilizing orthogonality on the frequency axis allows an AP to communicate with multiple STAs in parallel within a single specified bandwidth. The AP allocates RUs to each STA. The AP 101 may communicate with multiple STAs in parallel using multi-user MIMO (Multiple-Input and Multiple-Output) communication. In this case, the AP has multiple antennas, and transmits different signals from each antenna using the same frequency channel. Each STA simultaneously receives the signals transmitted from each antenna, separates the signals, and decodes each signal. In MIMO communication, the propagation paths used for communication between the AP and each STA are spatially orthogonal. This configuration utilizing spatial orthogonality allows the AP to communicate with multiple STAs in parallel within a single specified bandwidth. By performing multi-user communication in this way, the AP can communicate more data with each STA in the same amount of time than if it were not performing multi-user communication.

[0015] Generally, in communication methods conforming to the IEEE 802.11 standard series, the AP 101 communicates with the STA 110 by directly exchanging wireless frames. At this time, the available communication method may vary depending on the distance between the AP 101 and the STA 110. For example, in FIG. 1 , the STA 112 is located closer to the AP 101 than the STA 111, and therefore may use a more efficient communication method. Here, the communication method may be, for example, a modulation method, a coding method, a MIMO multiplexing number, a guard interval length, a frequency bandwidth, etc. In other words, when the distance between the communication devices 100 is short, the RSSI and SNR are high, making it possible to use a highly efficient communication method, such as a modulation method with a high number of multilevels or a coding method with low redundancy. RSSI is an abbreviation for Received Signal Strength Indicator, and is also referred to as received signal strength. Furthermore, SNR is an abbreviation for Signal to Noise Ratio, and is also referred to as the signal-to-noise ratio. In other words, STAs located far from the AP use a communication method with a relatively low efficiency, which may reduce the communication capacity of the entire network. Furthermore, as the distance between the AP and the STA increases, the error rate of wireless frames may increase. In such a situation where the distance between the AP and the STA is large, it may be possible to improve the efficiency and stability of communication by having another STA relay the communication between these communication devices. For example, in FIG. 1, when STA 112 relays communication between AP 101 and STA 111, STA 112 is referred to as a relay STA (Relay-STA). Furthermore, STA 111, which is the communication partner of AP 101 and is capable of performing relay communication, is referred to as an end STA (End-STA). Note that in this embodiment, relay, relay, and Relay are interchangeable terms. By performing relay communication between the AP 101 and the end STA 111 via relay by the relay STA 112, there is a possibility that efficiency will be higher than when the AP 101 and the STA 111 communicate directly.However, unless each communication device is capable of relay communication and each communication device mutually knows that the other communication device can perform relay communication, there is a possibility that communication between the communication devices cannot be properly relayed. For example, in the situation of FIG. 1 , if the relay STA 112 does not know whether the end STA 111 supports relay communication, the relay STA 112 does not know whether to relay communication between the AP 101 and the end STA 111. Furthermore, if the relay STA 112 does not know the communication method that can be used with the end STA 111, there is a possibility that data transmitted by the relay STA 112 will not be correctly received by the end STA 111. Here, generally, the STA 111 and the STA 112 each communicate with the AP 101, and communication between the STA 111 and the STA 112 is not performed. Therefore, the STA 112 does not know the capabilities of the STA 111 or the communication parameters that the STA 111 can use. Therefore, there is a possibility that the relay STA 112 may not be able to properly relay the communication between the AP 101 and the end STA 111 .

[0016] In consideration of these circumstances, the STA in this embodiment acquires information about end STAs from an AP in order to operate as a relay STA. For example, the STA functions as a first STA (relay STA) that relays communication between the AP to which the STA is connected and one or more other STAs connected to the AP. The STA then receives a predetermined frame from the AP including identification information that identifies a second STA (end STA) among the other STAs that has a predetermined capability for communicating with the AP via relaying by the first STA. Furthermore, when operating as the first STA, the STA relays communication between the AP and the second STA identified by the identification information. Meanwhile, the AP in this embodiment may communicate with another STA connected to the STA via relaying by the first STA connected to the STA. In this case, the AP identifies a second STA among the other STAs that has a predetermined capability for communicating via relaying by the first STA, and transmits a predetermined frame including identification information that identifies the second STA to the first STA. When communicating via relaying by the first STA, the AP communicates with the second STA. With this configuration, the STA can identify a STA capable of performing relay communication as an end STA by using information acquired via the AP to operate as a relay STA. The STA may also acquire capability information indicating the predetermined capabilities of the second STA identified by the identification information. For example, the capability information may be information indicating the ability to transmit frames in a predetermined format used for communication via relaying by the first STA. The capability information may also be information indicating the ability to receive frames in a predetermined format used for communication via relaying by the first STA. With this configuration, the STA can perform relay operations based on the capabilities of the end STA when operating as the first STA. For example, the STA may relay using frames in a format usable by the end STA.

[0017] The capability that an end STA may have to perform relay communication may be that the end STA receives a data frame from a relay STA based on an instruction from an AP. The capability that an end STA may have to perform relay communication may be that the end STA transmits a data frame to a relay STA based on an instruction from an AP. The capability that an end STA may have to perform relay communication may be that the end STA instructs the relay STA to relay to the AP. The capability that an end STA may have to perform relay communication may be that the end STA transmits a data frame to a relay STA based on an instruction from an AP. The capability that an end STA may have to perform relay communication may be that the end STA can transmit using a frame in a format for relay communication. The capability that an end STA may have to perform relay communication may be that the end STA can receive using a frame in a format for relay communication. The capability that an end STA may have to perform relay communication may be that the end STA can communicate frames using a frame exchange procedure for relay communication. The capability that an end STA may have to perform relay communication may be that the end STA is capable of communicating using a communication method for relay communication. For example, the communication method may be a modulation method, a coding method, a data multiplexing method, an encryption method, etc. The capability that an end STA may have to perform relay communication may be that the end STA is capable of processing frames for relay communication. Processing frames for relay communication may include extracting data frames from frames for relay communication and encapsulating data frames into frames for relay communication. Furthermore, processing frames for relay communication may include converting headers of frames for direct communication into a frame format for relay communication, converting headers of frame formats for relay communication into headers for direct communication, etc.

[0018] The capability of an AP to perform relay communication may be that the AP instructs a relay STA to relay to an end STA. The capability of an AP to perform relay communication may be that the AP instructs an end STA to perform relay communication. The capability of an AP to perform relay communication may be that the AP determines whether to perform direct communication or relay communication with an end STA. The capability of an AP to perform relay communication may be that the AP is capable of transmitting using frames in a format for relay communication. The capability of an AP to perform relay communication may be that the AP is capable of receiving using frames in a format for relay communication. The capability of an AP to perform relay communication may be that the AP is capable of communicating frames using a frame exchange procedure for relay communication. The capability of an AP to perform relay communication may be that the AP is capable of communicating using a communication method for relay communication. The capability of an AP to perform relay communication may be that the AP is capable of processing frames for relay communication.

[0019] The capability that the relay STA may have to perform relaying may be that the relay STA relays communication between the AP and the end STA based on an instruction from the AP. The capability that the relay STA may have to perform relaying may be that the relay STA is capable of transmitting using a frame in a format for relay communication. The capability that the relay STA may have to perform relaying may be that the relay STA is capable of receiving using a frame in a format for relay communication. The capability that the relay STA may have to perform relaying may be that the relay STA is capable of communicating frames using a frame exchange procedure for relay communication. The capability that the relay STA may have to perform relaying may be that the relay STA is capable of communicating using a communication method for relay communication. The capability that the relay STA may have to perform relaying may be that the relay STA is capable of processing frames for relay communication.

[0020] The relay STA may notify the AP of the communication quality between itself and the end STA. The relay STA may also notify the end STA of the communication quality between itself and the AP. For example, the AP may acquire the communication quality between itself and the end STA, the communication quality between itself and the relay STA, and the communication quality between the end STA and the relay STA. Based on these communication qualities, the AP may determine whether communication with the end STA should be performed via direct communication or relay communication via the relay STA. The communication quality may be acquired, for example, by measuring the RSSI, SNR, data rate, delay time, etc. when receiving a wireless frame. The wireless frame may include a data frame, a management frame, a control frame, etc. This configuration enables the AP to select whether to communicate with each STA directly or via relay based on the network status. The device configurations, functional configurations, and processing flow of the AP, end STA, and relay STA are described below.

[0021] 2 shows an example of the hardware configuration of the communication device 100 (AP 101 and STA 110) according to this embodiment. As an example of the hardware configuration, the communication device 100 has, for example, 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. The communication device 100 may have multiple antennas.

[0022] The storage unit 201 is configured with one or more memories including ROM, RAM, etc., and may store various information such as control programs for each functional unit constituting the communication device 100 to perform various operations, and parameters for communication. ROM and RAM stand for Read Only Memory and Random Access Memory, respectively. The storage unit 201 may be configured to include, in addition to memories such as ROM and RAM, storage media such as a flexible disk, a hard disk, an optical disk, a magneto-optical disk, a CD-ROM, a CD-R, a magnetic tape, a non-volatile memory card, and a DVD.

[0023] The control unit 202 is configured with one or more processors including, for example, a CPU, an MPU, etc., and controls the entire communication device 100 by executing a control program stored in the storage unit 201. The control unit 202 may control the entire communication device 100 in cooperation with the control program stored in the storage unit 201 and an OS (Operating System). The CPU and MPU are abbreviations for Central Processing Unit and Micro Processing Unit, respectively. When the control unit 202 has multiple processors that can be implemented using a multi-core or the like, the entire communication device 100 may be configured to be controlled by the multiple processors.

[0024] The control unit 202 also controls the functional unit 203 to perform predetermined processes such as communication, image capture, printing, and projection. The functional unit 203 is hardware that enables the communication device 100 to perform the predetermined processes described above. For example, if the device is a camera, the functional unit 203 is an image capture unit that performs image capture processing. For example, if the device is a printer, the functional unit 203 is a print unit that performs print processing. For example, if the device is a projector, the functional unit 203 is a projection unit that performs projection processing.

[0025] The input unit 204 receives various operations from the user. The output unit 205 outputs various types of information to the user via a monitor screen or a speaker. The output from the output unit 205 may be a display on the monitor screen, an audio output from a speaker, a vibration output, or the like. The input unit 204 and the output unit 205 may both be implemented as a single module, such as a touch panel. The input unit 204 and the output unit 205 may be integrated into the communication device 100 or may be separate devices.

[0026] The communication unit 206 controls wireless communication compliant with the IEEE 802.11bn standard. Furthermore, the communication unit 206 may control wireless communication compliant with other IEEE 802.11 standard series, such as legacy standards, in addition to the IEEE 802.11bn standard. The communication unit 206 controls the antenna 207 to transmit and receive signals for wireless communication generated by the control unit 202. The communication unit 206 is a so-called wireless chip and may itself include one or more processors and memories. Note that if the communication device 100 supports other wireless communication standards, such as the NFC standard or the Bluetooth standard, or wired communication such as a wired LAN, in addition to the IEEE 802.11bn standard, the communication unit 206 may control communication compliant with these communication standards. Furthermore, if the communication device 100 can perform wireless communication compliant with multiple communication standards, the communication device 100 may be configured to have separate communication units and antennas corresponding to each communication standard. The communication device 100 communicates data with a communication device of a partner via the communication unit 206. The antenna 207 may be configured as a separate unit from the communication unit 206, or may be configured together with the communication unit 206 as a single module.

[0027] Antenna 207 is an antenna capable of communication in, for example, the 2.4 GHz band, the 5 GHz band, the 6 GHz band, millimeter waves, etc. Although Fig. 2 shows a configuration in which communication device 100 has two antennas 207, communication device 100 may have one or three or more antennas, or may have one or more antennas for each frequency band that the device can use. Furthermore, if communication device 100 has multiple antennas, communication device 100 may have a communication unit 206 for each antenna.

[0028] (Functional Configuration) The functional configuration of the communication device 100 (AP 101 and STA 110) in this embodiment will be described. FIG. 3 shows an example of a block diagram of the AP 101. FIG. 4 shows an example of a block diagram of the STA 110. These functions can be realized, for example, by the control unit 202 executing a program stored in the storage unit 201, or by a processing function unit in the communication unit 206. Note that FIGS. 3 and 4 are diagrams explaining the main functions of this embodiment, and other functions are omitted. Therefore, for example, a control function for establishing a connection between a normal AP and a STA and for communication, as well as functions generally possessed by a communication device, can naturally be possessed. Furthermore, multiple functional blocks in FIGS. 3 and 4 may be integrated into a single functional block, or a single functional block may be divided into multiple functional blocks.

[0029] 3 shows an example configuration of the AP 101. The AP 101 may be configured to include a frame processing unit 301, a frame transmission / reception unit 302, a relay control unit 303, and an end STA information notification unit 304. The frame processing unit 301 analyzes various wireless frames received from the outside by the frame transmission / reception unit 302, and performs notification to an upper layer (not shown) and wireless communication control processing based on the analysis results. For example, when the AP 101 transmits data, the frame processing unit 301 generates a data frame. When the AP 101 receives data, the frame processing unit 301 processes the data frame. The frame processing unit 301 generates and processes management frames and data frames. Management frames may be, for example, a beacon frame, a probe response frame, an authentication frame, an association response frame, or a reassociation response frame. The management frame may be a Probe Request frame, an Association Request frame, a Reassociation Request frame, a Block Ack (BA) frame, an Action frame, or the like.

[0030] The frame transceiver 302 cooperates with the antenna 207 to receive wireless frames such as UHR PPDUs transmitted from other communication devices. PPDU is an abbreviation for Physical Layer Protocol Data Unit. The frame transceiver 302 also transmits wireless frames such as UHR PPDUs generated by the frame processor 301 to other communication devices (other APs or STAs). The frame transceiver 302 can transmit and receive frames in a predetermined format used for communication via relay by a relay STA.

[0031] The relay control unit 303 executes a function for controlling relay communication. For example, the relay control unit 303 determines whether each of the STAs connected to the device has a predetermined capability for communication via relay by a relay STA. The relay control unit 303 also acquires information on communication quality from the relay STA and the end STA, and determines whether to communicate with the end STA via relay by the relay STA based on the capability, communication quality, etc. of the end STA. The relay control unit 303 controls the frame transmission / reception unit 302 to communicate with the end STA via relay by the relay STA.

[0032] The end STA information notification unit 304 notifies the relay STA of information about the end STA acquired by the relay control unit 303. For example, the end STA information notification unit 304 may notify the relay STA of specific information that identifies a STA capable of performing relay communication as an end STA. Furthermore, the end STA information notification unit 304 may notify the relay STA of capability information that indicates the capabilities of the end STA capable of performing relay communication. For example, the end STA information notification unit 304 may notify the above-mentioned specific information and capability information using a Beacon frame, an Action frame, or the like that includes an End-STA List field.

[0033] FIG. 4 shows an example configuration of the STA 110. The STA 110 may include a frame processing unit 401, a frame transmitting / receiving unit 402, a relay processing unit 403, and an end STA information acquisition unit 404. The operations of the frame processing unit 401 and the frame transmitting / receiving unit 402 are similar to those of the frame processing unit 301 and the frame transmitting / receiving unit 302, and therefore will not be described here. When the STA 110 operates as a relay STA, the frame transmitting / receiving unit 402 relays communication between the AP 101 and the end STA in accordance with instructions from the relay processing unit 403. The relay processing unit 403 executes a function for relay communication. For example, the relay processing unit 403 manages information about the end STA acquired by the end STA information acquisition unit 404. The relay processing unit 403 may also measure the communication quality between the STA 110 and the AP 101 or the end STA, and notify the respective communication devices of the measurement results. Furthermore, the relay processing unit 403 may analyze a frame in a format for relay communication received by the frame transceiver unit 402 from the AP 101 or an end STA, and may use the frame transceiver unit 402 to relay the data frame. The end STA information acquisition unit 404 may acquire information on end STAs capable of performing relay communication from the AP. For example, the end STA information acquisition unit 404 may acquire, from the AP, specific information that identifies the end STA. Furthermore, the end STA information acquisition unit 404 may acquire, from the AP, capability information that indicates the capabilities of the end STA. For example, the end STA information acquisition unit 404 may acquire the above-mentioned specific information and capability information using a Beacon frame, an Action frame, or the like that includes an End-STA List field.

[0034] (Processing Example) A connection procedure between communication devices 100 in this embodiment will be described. Fig. 5 is a diagram showing an example of a message sequence between communication devices 100. In this example, a connection procedure when AP 101 communicates with end STA 111 via relay STA 112 is shown.

[0035] (Connection Processing and Capability Information Exchange Between AP, End STA, and Relay STA) AP 101 periodically broadcasts information about the BSS it configures. For example, AP 101 notifies capability information indicating that it is capable of performing relay communication (F501). AP 101 may notify information about the BSS and capability information using a beacon that it periodically transmits. AP 101 may also notify capability information using a method other than notification by beacon. For example, AP 101 may notify capability information using a probe response, etc. Capability information indicating that AP 101 is capable of performing relay communication may be notified using a UHR Capability element included in a beacon, etc. Note that this embodiment will be described using an example in which a UHR Capability element is used, but this is not limited to this element and may also be, for example, a UHR MAC capability element or a Multi Link element. The UHR MAC capability element is an information element capable of notifying MAC layer information, and the Multi Link element is an information element capable of notifying capability information for each link when communication is performed using multiple links.

[0036] When the end STA 111 detects the AP 101, it executes a connection process (F502). For example, the end STA 111 may execute the connection process by transmitting a Probe Request, an Association Request, an Authentication, or the like, and receiving a response from the AP 101 in response to these. Furthermore, when the end STA 111 acquires capability information indicating that the AP 101 is capable of performing relay communication via a Beacon, a Probe Response, or the like, it may notify the AP 101 of its own capability information in the connection process. For example, the end STA 111 may transmit an Association Request frame including capability information indicating that the end STA 111 is capable of performing relay communication as an end STA. Furthermore, the end STA 111 may transmit a Probe Response frame or an Authentication frame including capability information indicating that the end STA 111 is capable of performing relay communication. For example, the end STA 111 may transmit these frames including a UHR Capability element. By exchanging these frames, a connection is established between the AP 101 and the end STA 111, and each party can confirm that the other party is capable of performing relay communication.

[0037] When the AP 101 receives an Association Request frame or the like including information indicating the capability information of the end STA 111 (F502), the AP 101 transmits an Association Response including information indicating the capability information of its own device (F503). By receiving the Association Response, the end STA 111 can confirm that the AP 101 is capable of performing relay communication. This allows the AP 101 and the end STA 111 to mutually confirm that they are capable of performing relay communication.

[0038] When the relay STA 112 detects the AP 101, it performs connection processing (F504). The connection processing between the AP 101 and the relay STA 112 and the exchange of capability information related to relay communication can be performed in the same manner as the connection processing between the AP 101 and the end STA 111 and the exchange of capability information related to relay communication. The relay STA 112 can notify the AP 101 that it is capable of operating as a relay STA in relay communication. For example, the relay STA 112 can transmit a Probe Request frame or the like including a UHR Capability element indicating that it is capable of operating as a relay STA in relay communication.

[0039] When the AP 101 receives an Association Request frame or the like including information indicating the capability information of the relay STA 112 (F505), the AP 101 transmits an Association Response including information indicating the capability information of its own device (F506). By receiving the Association Response, the relay STA 112 can confirm that the AP 101 is capable of performing relay communication. This establishes a connection between the AP 101 and the relay STA 112, and the AP 101 can recognize that the relay STA 112 is capable of performing relay communication as a relay STA.

[0040] 6 shows an example of the configuration of a UHR Capability element. The UHR Capability element includes an Element ID field 601, a Length field 602, and an Extended Element ID field 603. The UHR Capability element may also include a Relay Transmit Capable field 604 and a Relay Receive Capable field 605. The Element ID field 601 and the Extended Element ID field 603 indicate that this element is a UHR Capability element. For example, if 255 is set in the Element ID field 601 and 138 is set in the Extended Element ID field 603, this indicates that this element is a UHR Capability Element. The Length field 602 indicates the length of this element.

[0041] The Relay Transmit Capable field 604 indicates that the communication device that is the sender of the wireless frame including this element is capable of performing a transmission operation using relay communication as an AP or an end STA. For example, the AP 101 may use this field to indicate that it can transmit a data frame to the end STA 111 via relay by the relay STA 112. As an example, if this field is set to 1, it may indicate that it can transmit a data frame to the end STA 111 via relay by the relay STA 112. The end STA 111 may use the Relay Transmit Capable field 604 to notify that it can transmit a data frame to the AP 101 via relay by the relay STA. As an example, if this field is set to 1, it may indicate that it can transmit a data frame to the AP 101 via relay by the relay STA 112. The Relay Receive Capable field 605 indicates that the communication device that transmitted the wireless frame including this element is capable of performing a receiving operation using relay communication as an AP or an end STA. For example, the AP 101 may use this field to indicate that it can receive a data frame transmitted by the end STA 111 via relay by the relay STA 112. As an example, if this field is set to 1, it may indicate that it can receive a data frame from the end STA 111 via relay by the relay STA 112. Furthermore, the STA 111 may use the Relay Receive Capable field 605 to notify that it can receive a data frame from the AP 101 via relay by the relay STA. As an example, if this field is set to 1, it may indicate that it can receive a data frame from the AP 101 via relay by the relay STA 112. The Relay Transmit Capable field 604 and the Relay Receive Capable field 605 may be combined into one field or one bit, indicating that communication using relay communication is possible.That is, it may indicate that both transmission and reception operations using relay communication are possible. Note that if the capability to transmit and receive the UHR Capability element indicates that at least reception operations in relay communication are possible, the Relay Receive Capable field 605 may be omitted. That is, if the IEEE 802.11bn standard specifies reception operations in relay communication as a required function and transmission operations in relay communication as an optional function, products conforming to this standard are capable of reception operations in relay communication. Therefore, by omitting signaling for required functions and configuring to notify only optional functions, the number of bits constituting a frame can be reduced.

[0042] The Relay AP Capable field 606 and the Relay STA Capable field 607 indicate that the communication device that transmits the wireless frame including these elements can operate as a relay STA in relay communication. That is, when either of these fields is set to 1, it indicates that the communication device that transmits the wireless frame can receive a data frame transmitted by the AP 101 and transmit it to another STA. Similarly, it indicates that the communication device that transmits the data frame can receive a data frame transmitted by another STA and transmit it to the AP 101. Note that when the Relay AP Capable field 606 is set to 1, it may indicate that the communication device that transmits the wireless frame can operate as a relay STA that can perform some of the functions that the AP performs. Examples of functions that are the same as some of the functions that the AP performs may include, for example, transmitting beacon frames and processing connections with STAs. That is, the functions that the AP should perform may be performed by STAs connected to this AP. On the other hand, when the Relay STA Capable field 607 is set to 1, it may indicate that the source communication device operates as a relay STA but does not perform some of the functions performed by the AP described above. Note that instead of the Relay AP Capable field 606 and the Relay STA Capable field 607, one field may indicate that the source communication device can operate as a relay STA. In this case, another field may indicate whether the source STA performs some of the functions performed by the AP.

[0043] (Exchange of Information Regarding End STAs) When the relay STA 112 establishes a connection with the AP 101, it acquires information for identifying the end STAs. That is, the relay STA 112 acquires information for identifying STAs that are capable of performing relay communication among the STAs connected to the AP 101. For example, the relay STA 112 may request the AP 101 to provide identification information for identifying the end STAs by transmitting a Relay Request frame (F506). Upon receiving the request from the relay STA 112, the AP 101 may notify the relay STA 112 of the information for identifying the end STAs (F507). For example, the AP 101 may notify the relay STA 112 of the identification information for identifying the end STAs by transmitting a Relay Response frame.

[0044] The Relay Request frame may be one of the UHR Protected Action frames. Fig. 7A shows an example of the configuration of a Relay Request frame. The UHR Protected Action frame includes a Category field 701, a Protected UHR Action field 702, a Dialog Token field 703, and a Relay Control field 704. The Category field 701 stores an identification number indicating Protected UHR. For example, a value of 40 may be set. The Protected UHR Action field 702 indicates the identifier of this Action field in the Protected UHR category. For example, the Protected UHR Action field 702 may be set with a value indicating that this is an Action field related to relay communication. The Dialogue Token field 703 indicates an identifier that uniquely identifies a series of information exchanges between the AP 101 and the STA 112. For example, an identifier assigned by the relay STA 112 that transmitted the Relay Request frame is stored in the Dialogue Token field 703. In response to the Relay Request frame, the AP 101 stores the value included in the received Dialogue Token field 703 in the Dialogue Token field 703 of a response frame and transmits the response frame. The Relay Control field 704 includes a Relay Action field 711. The Relay Action field 711 indicates a value corresponding to a process to be performed in relation to the relay communication. For example, when each of the Relay Request (F506), Relay Response (F507), and SNR Notify (F509, F510) shown in FIG. 5 is transmitted in an Action frame, a value identifying each of them is set.

[0045] The Relay Response frame may be one of the UHR Protected Action frames. Fig. 7B shows an example of the configuration of a Relay Response frame. The Relay Response frame may include an End-STA List field 705 following a Relay Control field 704. Note that the End-STA List field 705 may be included in the Relay Control field 704. The End-STA List field 705 indicates information about end STAs belonging to the AP 101. Note that the End-STA List field 705 may include information about all STAs belonging to the AP 101. In this case, the End-STA List field 705 may include information that can identify whether each STA included in this field is capable of performing relay communication as an end STA. The End-STA List field 705 may include information about one or more end STAs.

[0046] The End-STA List field 705 may include a STA Number field 712 and one or more STA Info fields 713. The STA Number field 712 may indicate the number of subsequent STA Info fields. For example, if two end STAs are connected to the AP 101 and may perform relay communication, the value of the STA Number field 712 may be set to 2. In this case, there may be two STA Info fields 713 corresponding to each end STA. A Length field may be added at the beginning of the End-STA List field 705 to indicate the length of the End-STA List field 705.

[0047] Each STA Info field 713 includes information about the corresponding end STA. For example, the STA Info field 713 may include a STA Address field 721, a Maximum MPDU Length field 722, and a Support For 320 MHz field 723. The STA Info field 713 may also include a Beamformee SS field 724 and a Supported EHT-MCS And NSS Set field 725. The STA Info field 713 further includes a Relay Transmit Capable field 726 and a Relay Receive Capable field 727. The STA Address field 721 indicates information for identifying the corresponding end STA. For example, the STA Address field 721 indicates the MAC Address or AID of the end STA. AID is an abbreviation for Association Identifier. The Maximum MPDU Length field 722 indicates the maximum size of A-MSDU that the end STA can process. MPDU is an abbreviation for MAC Protocol Data Unit. A-MSDU is an abbreviation for Aggregate MAC Service Data Unit. For example, when the value of the Maximum MPDU Length field 722 is 0, 1, or 2, respectively, 3895 octets, 7991 octets, or 11454 octets may be associated as the maximum size of the A-MSDU. The Support For 320 MHz field 723 indicates whether or not the end STA supports the use of a 320 MHz frequency bandwidth. For example, when the value of the Support For 320 MHz field 723 is set to 0, this may indicate that the end STA does not support the use of a 320 MHz frequency bandwidth. Furthermore, when the value of the Support For 320 MHz field 723 is set to 1, this may indicate that the end STA supports the use of a 320 MHz frequency bandwidth. Note that the Support For 320 MHz field 723 may be provided for each frequency band.For example, a field or bit may be provided for each frequency band, such as the 2.4 GHz band, the 5 GHz band, or the 6 GHz band, indicating whether or not the use of a 320 MHz frequency bandwidth is supported. The Beamformee SS field 724 indicates the maximum number of spatial streams that the end STA can use in beamforming reception processing. The Beamformee SS field 724 may be provided for each frequency bandwidth that the end STA can use. For example, a field or bit may be provided for each frequency bandwidth of 80 MHz, 160 MHz, and 320 MHz, indicating the maximum number of spatial streams that can be used. The Supported EHT-MCS And NSS Set field 725 indicates the combination of the MCS and the number of spatial streams supported by the end STA. MCS is an abbreviation for Modulation and Coding Scheme. The Supported EHT-MCS and NSS Set field 725 may be expressed as a bitmap. For example, for each of transmission and reception, a bit associated with a usable MCS may be provided for each number of spatial streams usable by the end STA. For example, a bit value corresponding to a combination of an MCS usable by the end STA and the number of spatial streams may be set to 1. The Supported EHT-MCS and NSS Set field 725 may further be expressed as a bitmap for each frequency bandwidth usable by the end STA. For example, a bitmap corresponding to each of 80 MHz, 160 MHz, 320 MHz, etc. may be provided as frequency bandwidths usable by the end STA.

[0048] The Relay Transmit Capable field 726 indicates that the end STA has the capability to transmit data frames to the AP via relay by a relay STA. For example, this indicates that STA 111 in FIG. 1 can transmit data to AP 101 via STA 112. The Relay Receive Capable field 727 indicates that the end STA has the capability to receive data frames from the AP via relay by a relay STA. For example, this indicates that STA 111 in FIG. 1 can receive data transmitted by AP 101 via STA 112. Note that the Relay Transmit Capable field 726 and the Relay Receive Capable field 727 may be combined into a 1-bit field to indicate that both transmission and reception via relay communication are possible.

[0049] Note that the method by which the AP 101 notifies the relay STA 112 of information for identifying end STAs capable of relay communication is not limited to the Relay Response frame. For example, the AP 101 may notify the relay STA 112 using a predetermined information element included in a Beacon frame or a Probe Response frame that it periodically transmits (F508). If information for identifying end STAs is included in a Beacon frame or the like, the relay STA 112 can identify end STAs capable of relay communication without transmitting a Relay Request frame. As an example, the predetermined information element may be a UHR Capability element. In this case, the UHR Capability element may include the End-STA List field described above. FIG. 8 shows an example of the configuration of a UHR Capability element including an End-STA List field 705. In Figure 8, fields with the same content as in Figures 6 and 7 are assigned the same reference numbers, and descriptions thereof will be omitted. That is, the UHR Capability element in Figure 8 includes the End-STA List 705 shown in Figure 7 based on the configuration in Figure 6. Note that the predetermined information element may be a UHR Operation element. In this case, the configuration is also the same as in Figure 8, and the values ​​of the Element ID field 601 and the Extended Element ID field 603 may be 255 and 139, respectively. Note that the information included in STA Info 713 in Figure 8 may be included in a field other than the STA Info field 713. For example, it may be included in an element other than the UHR Capability element or UHR Operation. For example, each field may be included in any, some, or all of an HT Capability Element, a VHT Capability Element, an EHT Capability Element, etc. For example, each field may be included in any, some, or all of a UHR Capability Element, an Extended Capability Element, etc.The location of each field and the method of expression are not limited to these, and it is sufficient that the information is notified as reference information for the end STA when the relay STA performs relay communication.

[0050] Alternatively, specific information for identifying the end STA may be transmitted via a Beacon frame, and the capability information and available communication parameters of the end STA may be transmitted via a Relay Response frame. That is, by receiving the Beacon frame, the relay STA 112 may identify the STA to be relayed by itself, and, if necessary, individually acquire the available communication parameters of the end STA. This configuration reduces the number of fields included in the Beacon frame, and enables the relay STA 112 to provide further information about the end STA in response to a request from the relay STA 112. This enables efficient use of radio resources. In this case, the UHR Capability element and the UHR Operation element included in the Beacon frame may include only the STA Number field 712 and the STA Address field 721. The Relay Request frame transmitted by the relay STA 112 may also include a field for specifying a specific end STA about which the relay STA 112 requires information. In this case, the AP 101 may transmit a Relay Response frame that includes only the STA Info field 713 related to the specified end STA.

[0051] (Process for Determining Whether to Execute Relay Communication in the AP) Before executing communication with the end STA 111, the AP 101 may select whether to communicate directly with the end STA 111 or to communicate via relay by the relay STA 112. For example, the AP 101 may make this selection based on the communication quality between each communication device. In FIG. 5 , the relay STA 112 identifies the communication quality between itself and the AP 101 and the communication quality between itself and the end STA 112, and notifies the AP 101 and the end STA 112 (F509, F510). The relay STA 112 may periodically measure the communication quality. For example, the relay STA 112 may periodically measure the communication quality based on acquiring information identifying the end STA from the AP 101. That is, the relay STA 112 may measure the communication quality between itself and the AP 101 using a frame transmitted from the AP 101, such as a beacon frame. Furthermore, the relay STA 112 may measure the communication quality between itself and the end STA using a frame transmitted by the identified end STA. The relay STA 112 may measure the communication quality based on a request from the AP 101 and report the measurement to the AP 101 or the end STA 111. The information indicating the communication quality may be, for example, SNR, SINR, RSSI, transmission delay time, frame error rate, etc. SINR may be an abbreviation for Signal to Interference and Noise Ratio.

[0052] The relay STA 112 may notify the communication quality measurement result using an SNR Notify frame. The SNR Notify frame may be one of UHR Protected Action frames. The SNR Notify frame may include, for example, identification information for identifying the communication device that performed the communication quality measurement, the number of communication devices that were targets of the communication quality measurement, identification information for identifying the communication devices that were targets of the communication quality measurement, and information indicating the communication quality as the measurement result. For example, the identification information for identifying the communication device that performed the communication quality measurement in the SNR Notify frame generated by the relay STA 112 may be the MAC address or AID of the relay STA 112. If the SNR Notify frame generated by the relay STA 112 includes communication quality information related to the AP 101 and the end STA 111, the number of communication devices that were targets of the communication quality measurement may be two. When the relay STA 112 generates an SNR Notify frame for each communication device, the number of communication devices for which communication quality has been measured may be one. In this case, the field indicating the number of communication devices for which communication quality has been measured may be omitted. Furthermore, when the number of communication devices for which communication quality has been measured is two or more, the subsequent fields may be provided for each communication device. For example, the MAC addresses, BSSIDs, AIDs, etc. of the AP 101 and the end STA 111 may be included as identification information for identifying the communication devices for which communication quality has been measured. Furthermore, information indicating the communication quality as a measurement result may include information indicating the SNR, RSSI, etc. of a frame received from the AP 101 and the SNR, RSSI, etc. of a frame received from the end STA 111. The frame used by the relay STA 112 for measuring and notifying communication quality is not limited to the SNR Notify frame; for example, a Null Data Packet or a CSI Report frame may be used. CSI is an abbreviation for Channel Status Information.

[0053] Based on communication quality information acquired from the relay STA 112, the AP 101 may select whether to perform direct communication with the end STA 111 or relay communication via relay by the relay STA 112. In making this selection, the AP 101 may use the results of measuring the communication quality between the AP 101 and the end STA 111. The AP 101 may also acquire communication quality information from the end STA 111. For example, the AP 101 may select relay communication if a value indicating the communication quality between the AP 101 and the end STA 111 is below a predetermined threshold. Furthermore, the AP 101 may determine that the communication quality between the AP 101 and the relay STA 112 and the communication quality between the relay STA 112 and the end STA 111 are both above a predetermined threshold, and may select relay communication. The AP 101 may select direct communication if either the value indicating the communication quality between the AP 101 and the relay STA 112 or the value indicating the communication quality between the AP 101 and the relay STA 112 and the end STA 111 is below a predetermined threshold. The method by which the AP 101 selects whether to perform direct communication or relay communication is not limited to the above. For example, the AP 101 may determine whether to perform relay communication based on information other than communication quality. The AP 101 may determine whether to perform relay communication based on the geographical distance between the AP 101 and the end STA 111 or the location information of the end STA 111. The AP 101 may also determine whether to perform relay communication based on traffic characteristics, such as the required delay for traffic communicated with the end STA. The AP 101 may select whether to perform direct communication or relay communication each time it communicates a data frame with the end STA 111, or may perform the selection periodically.

[0054] (Data Frame Communication Processing by Relay Communication) The AP 101 communicates data frames with the end STA 111 (F511, F512). For example, when performing relay communication, the AP 101 transmits a data frame to the end STA 111 via the relay STA 112. The AP 101 may transmit a signal to reserve a period necessary for relay communication in advance, and transmit a data frame to the relay STA 112 within that period. As an example, the AP 101 may reserve a period necessary for relay communication by transmitting a Trigger frame. For example, a period including a period for the AP 101 to transmit a data frame to the relay STA 112 and a period for the relay STA 112 to transmit a data frame to the end STA 111 may be set in the Duration field of the Trigger frame. In addition, the Duration field may also include a period for an ACK or Block ACK to be returned from the end STA 111. In this case, in addition to the above-mentioned periods, the Duration field may be set with a period including a period for the end STA 111 to transmit an ACK or the like to the relay STA 112 and a period for the relay STA 112 to transmit an ACK or the like to the AP 101. Furthermore, the settings of the Duration field are not limited to these, and may be set with, for example, a period required for a procedure for performing relay communication, which will be described later. In this way, relay communication can be performed using the period secured by the Trigger frame.

[0055] The Trigger frame may include information indicating that relay communication will be performed. That is, the AP 101 may use the Trigger frame to notify the end STA 111 and the relay STA 112 in advance that communication will be performed via relay communication, and then transmit a data frame addressed to the end STA 111. In this case, the Trigger frame may include information indicating that the end STA 111 and the relay STA 112 should receive this Trigger frame. For example, the relay STA 112 and the end STA 111 may be indicated as the destinations of the Trigger frame. This allows the relay STA 112 and the end STA 111 to recognize that relay communication will be performed. Then, a data frame transmitted from the AP 101 after this Trigger frame is received by the relay STA 112 and transmitted to the end STA 111 by the relay STA 112. Alternatively, the destination field of the Trigger frame may indicate the relay STA 112, and another field of the Trigger frame may indicate the end STA 111 as the destination of the data frame. In this case, in response to receiving the Trigger frame, the relay STA 112 may transmit another Trigger frame to the end STA 111 indicating that relay communication will be performed. This may notify the end STA 111 that relay communication will be performed. In this case, the AP 101 may transmit a subsequent data frame based on the transmission of the Trigger frame from the relay STA 112. The relay STA 112 transmits the received data frame to the end STA 111. Note that the relay STA 112 does not need to transmit the Trigger frame to the end STA 111. In this case, the AP 101 transmits a data frame following the transmission of the Trigger frame addressed to the relay STA 112. The relay STA 112 can transmit the data frame received from the AP 101 to the end STA 111. This allows for more efficient use of radio resources than when a Trigger frame is transmitted from each of the AP 101 and the relay STA 112. Note that the Trigger frame can notify the end STA 111 of the frequency resources to be used in the relay communication.For example, the Trigger frame may include information indicating an RU to be used when transmitting a data frame from the AP 101 to the relay STA 112, and information indicating an RU to be used when transmitting a data frame from the relay STA 112 to the end STA 111. When OFDMA communication is used, it becomes possible to flexibly select the RU to be used in each transmission. The frame used for notifying relay communication and reserving radio resources is not limited to the Trigger frame. For example, the AP 101 may transmit an RTS frame including a Duration field in which a period required for relay communication is set, and may receive a CTS frame in response to this, thereby reserving the period required for relay communication. In addition, the RTS frame may be used to notify information indicating that relay communication will be performed.

[0056] Furthermore, the AP 101 may perform relay communication using a data frame formatted for relay communication without prior notification of the execution of relay communication using a trigger frame or the like. For example, the AP 101 may transmit a data frame addressed to the relay STA 112, including information indicating relay communication and information that can identify the end STA. The information indicating relay communication and information that can identify the end STA may be included in the header of this data frame. In this case, upon receiving this data frame, the relay STA 112 may transmit a data frame of the same format with the destination changed to the end STA 111. The relay STA 112 may also generate and transmit a data frame formatted for direct communication using the received data frame. In this case, the destination of the data frame becomes the end STA 111, and the information indicating relay communication may be deleted. In these cases, the end STA 111 performs reception processing for the data frame addressed to the AP 101. The AP 101 may also transmit a data frame for relay communication that includes information that can identify the relay STA and the end STA, respectively, and information indicating that the data frame is for relay communication. In this case, the relay STA 112 can transmit the received data frame as is to the end STA 111. The end STA 111 can perform reception processing for the received data frame based on the information indicating that the data format is for relay communication.

[0057] The same procedure as above can be applied when transmitting a data frame from the end STA 111 to the AP 101. In this case, the AP 101 can inquire of the end STA 111 whether or not it has stored data in order to determine whether or not there is data to be transmitted to the end STA 111. If the end STA 111 has stored data, the AP 101 can transmit a Trigger frame to reserve resources for the period required for communication. This Trigger frame can also include an instruction to the end STA 111 to transmit the data frame. The end STA 111 can transmit the data frame based on the instruction in the Trigger frame. The end STA 111 can transmit the data frame using a data frame in the above-described relay communication format.

[0058] (Processing Flow in AP 101) The operation when the AP 101 notifies the relay STA 112 of information about the end STA will be described. FIG. 9 shows an example of a processing flow when the AP 101 notifies the relay STA 112 of information about the end STA. This processing may be the processing of the AP 101 when the AP 101 in FIG. 1 operates as an AP and the relay STA 112 connects to the AP 101. Note that this processing may be repeatedly executed after the connection with the relay STA 112 is established. First, the AP 101 performs connection processing with the relay STA 112 (S901). During the connection processing or after the connection is established, the AP 101 determines whether or not the relay STA 112 has requested the AP 101 to provide information about the end STA (S902). For example, the AP 101 determines whether or not a Relay Request frame has been received from the relay STA 112 (S902). If it is determined that there is no request for information about an end STA (NO in S902), the AP 101 ends this process. On the other hand, if there is a request for information about an end STA (YES in S902), the AP 101 determines whether or not the AP 101 manages information about the end STA (S903). That is, the AP 101 may determine whether or not one or more end STAs are connected to the AP 101. The AP 101 may also determine whether or not it manages information about STAs connected to the AP 101 that can perform relay communication. If it is determined that there is no information about end STAs that the AP 101 manages (NO in S903), the AP 101 notifies the relay STA 112 that there is no information that the AP 101 manages (S907) and ends this process. On the other hand, if there is information about end STAs that the AP 101 manages (YES in S903), the AP 101 notifies the relay STA 112 of the information about the end STAs that the AP 101 manages (YES in S903), the AP 101 notifies the relay STA 112 of the information about the end STAs (S904). The information about the end STA notified by the AP 101 may be information that can identify the end STA, communication parameters that the end STA can use for relay communication, etc. Then, the AP 101 determines whether or not it has acquired information about the communication quality related to its own device and the end STA from the relay STA 112 (S905). If information about the communication quality has not been acquired (NO in S905), the AP 101 ends this process.On the other hand, if information regarding communication quality has been acquired (YES in S905), the AP 101 stores the information and ends this process. In this way, the AP 101 can notify the relay STA 112 of the information regarding the end STA. The relay STA 112 can identify the communication quality between itself and the end STA based on the information regarding the end STA acquired from the AP 101 and provide this information to the AP 101. Furthermore, the AP 101 can select whether or not to perform communication via relaying of the relay STA 112 based on the information regarding communication quality provided by the relay STA 112. Furthermore, the relay STA 112 can relay communication between the AP 101 and the end STA using communication parameters and the like usable by the end STA acquired from the AP 101.

[0059] (Processing Flow in STA 112) The operation when the STA 112 acquires information about the end STA from the AP 101 will be described. FIG. 10 shows an example of a processing flow when the STA 112 acquires information about the end STA from the AP 101. This processing may be the processing of the relay STA 112 when the STA 112 in FIG. 1 operates as a relay STA and connects to the AP 101. The STA 112 may execute this processing when it detects the AP 101. Note that this processing may be executed repeatedly after the connection with the AP 101 is established. The STA 112 first performs connection processing with the AP 101 (S1001). The STA 112 may request the provision of information about the end STA during the connection processing or after the connection is established (S1002). For example, the STA 112 may transmit a Relay Request frame. If the STA 112 is unable to acquire information about the end STA (NO in S1003), the STA 112 terminates this processing. On the other hand, if the STA 112 acquires information about the end STA (YES in S1003), it stores the information about the end STA (S1004). Then, the STA 112 determines the communication quality between the STA itself and each of the AP 101 and the end STA based on the acquired information about the end STA (S1005). The STA 112 notifies the AP 101 and the end STA of information indicating the determined communication quality (S1006). In this way, the STA 112 can determine, for example, the communication quality between the STA itself and the identified end STA 111 based on the information about the end STA acquired from the AP 101, and report this to the AP 101. Based on this report, the AP 101 can determine whether to communicate with the end STA 111 via relaying by the STA 112, using the STA 112 as a relay STA, and can then communicate with the end STA 111. Furthermore, the STA 112 can relay communication between the AP 101 and the end STA 111 using communication parameters and the like that are available to the end STA 111 and that are acquired from the AP 101 .

[0060] (Variation 1) In the above processing example, the relay STA 112 transmits a Relay Request frame to acquire information about the end STA, and the AP 101 responds by transmitting a Relay Response frame. In this variation, the relay STA 112 notifies the AP 101 that it can operate as a relay STA in relay communication in an Association Request frame. In response, the AP 101 notifies the AP 101 of information about the end STA that can perform relay communication in an Association Response frame. With this configuration, the provision of information about the end STA is completed during the connection process, and therefore frame exchange using Relay Request frames, Relay Response frames, etc. between the AP 101 and the relay STA 112 is not required. This enables efficient use of wireless resources.

[0061] 11 is a diagram showing an example of a message sequence between communication devices 100 in this modification. In FIG. 11, the same reference numerals are used for operations similar to those in FIG. 5, and descriptions thereof will be omitted. First, a connection process is performed between the AP 101 and the end STA 111 (F502, F503). This establishes a connection between the AP 101 and the STA 111, and each device can confirm that the other device is capable of performing relay communication. Next, a connection process is performed between the AP 101 and the relay STA 112 (F504, F1101). At this time, the relay STA 112 notifies the other device that it is capable of operating as a relay STA in relay communication in an Association Request frame (F504). For example, the relay STA 112 may perform the notification using a Relay AP Capable field 606 or a Relay STA Capable field 607 of the UHR Capability element shown in FIG. 6. When the AP 101 receives the Association Request frame, it transmits an Association Response frame. At this time, if the AP 101 determines that the relay STA 112 has the capability to operate as a relay STA, it notifies the end STA of its information using the Association Response frame. For example, the AP 101 may notify the AP 101 by including a UHR Capability element or a UHR Operation element including the End-STA List field 705 of FIG. 8 in the Association Response frame. In this way, information about the end STAs may be provided from the AP 101 to the relay STA 112. Note that the relay STA 112 may explicitly request information about the end STAs in the Association Request frame. In this case, a field for requesting the provision of information about the end STAs may be provided in the Association Request frame. Furthermore, the relay STA 112 may notify the AP 101 by another frame that it is capable of operating as a relay STA for relay communication.For example, the relay STA 112 may perform the notification using a Probe Request frame, an Authentication frame, a Reassociation frame, or the like. In this case, the AP 101 may provide the relay STA 112 with information about STAs capable of performing relay communication using a frame other than an Association Response frame. For example, the AP 101 may notify the relay STA 112 by including an End-STA List field 705 in a Probe Response frame, an Authentication frame, a Reassociation Response frame, a Trigger frame, or the like. Furthermore, if the relay STA 112 can operate as a relay STA capable of performing some of the functions performed by the AP, the AP 101 may notify the relay STA 112 of information about STAs capable of performing relay communication when performing multi-AP communication. The ability of the relay STA 112 to operate as a relay STA capable of performing some of the functions performed by an AP may be indicated by a Relay AP Capable field 606 included in a UHR Capability element, etc. Furthermore, multi-AP communication may be a communication method in which multiple APs cooperate to communicate with end STAs. For example, in multi-AP communication, the relay STA 112 may relay communication between the AP 101 and the end STA 111, perform cooperative OFDMA with the AP 101, joint transmission, etc. In this case, the AP 101 may provide information about the end STA in a frame exchange procedure for requesting the relay STA 112 to perform multi-AP communication. Note that the operations of F509 to F512 in FIG. 11 are the same as those in FIG. 5.

[0062] (Variation 2) In the above processing example, the AP 101 establishes a connection with the end STA 111 and then performs connection processing with the relay STA 112. In this variation, a case where the AP 101 establishes a connection with the relay STA 112 and then establishes a connection with the end STA 111 is described. That is, in this example, when the relay STA 112 establishes a connection with the AP 101, the AP 101 does not have information about the end STA to provide. However, information about the end STA to provide is generated after the connection is established. Therefore, after establishing a connection with the AP 101, the relay STA 112 periodically requests the AP 101 to provide information about the end STA. In response, the AP 101 notifies the relay STA 112 of the information about the end STA. This configuration allows the relay STA 112 to update the information it manages if the situation regarding the end STA changes after the relay STA 112 connects to the AP 101. This allows the relay STA 112 to participate in relay communication with a larger number of end STAs.

[0063] FIG. 12 is a diagram showing an example of a message sequence between communication devices 100 in this modified example. Operations similar to those in FIG. 5 are assigned the same reference numerals, and a description thereof will be omitted. First, a connection process is performed between the AP 101 and the relay STA 112 (F504, F505). This establishes a connection between the AP 101 and the relay STA 112, and the AP 101 can confirm that the relay STA 112 is capable of operating as a relay STA in relay communication. Once the connection is established, the relay STA 112 requests the AP 101 to provide information about end STAs (F506). If no STAs other than the relay STA 112 are connected to the AP 101, the AP 101 can send a notification indicating that no end STAs exist (F507). For example, the AP 101 can send a Relay Response frame that does not include the End-STA List field 705. Note that the method by which the AP 101 sends a notification indicating that no end STAs exist is not limited to this. For example, the AP 101 may notify that there is no end STA capable of performing relay communication by setting a value of 0 in the STA Number field 712. The AP 101 may also transmit a Relay Response frame including information about the relay STA 112. In this case, the relay STA 112 may recognize that there is no other end STA capable of performing relay communication based on the fact that the Relay Response frame contains only its own information.

[0064] Next, connection processing is performed between the AP 101 and the end STA 111 (F502, F503). This establishes a connection between the AP 101 and the end STA 111, and each party can confirm that the other party is capable of performing relay communication. Then, when a predetermined period has elapsed since transmitting the Relay Request frame, the relay STA 112 requests the AP 101 to provide information about the end STA (F1201). In response to this, the AP 101 can send a notification including information about the end STA 111 (F1202). In this way, even after the connection between the relay STA 112 and the AP 101 is established, the AP 101 can provide information about the end STA to the relay STA 112. The AP 101 may also broadcast information about the end STA in a Beacon frame that it periodically transmits. In this case, the relay STA 112 can obtain information about STAs that can perform relay communication by obtaining the End-STA List field 705 included in the Beacon frame. Since frame exchange using a Relay Request frame, a Relay Response frame, or the like is not required between the AP 101 and the relay STA 112, wireless resources can be used effectively.

[0065] (Variation 3) In this variation, an example will be described in which the end STA 111 connected to the AP 101 disconnects. For example, when the end STA 111 disconnects, the AP 101 updates the information about the STAs it manages. The AP 101 then notifies the relay STA 112 of the updated information about the end STAs. The relay STA 112 then updates the information about the STAs it manages based on the notification from the AP 101. This configuration allows the relay STA 112 to update the information about the end STAs it manages if the status of the end STAs changes after the relay STA 112 connects to the AP 101. This allows the relay STA 112 to perform appropriate relay communication processing in response to the changes. For example, after the end STA 111 disconnects from the AP 101, the relay STA 112 may exclude the relay STA 111 from the targets of periodic communication quality measurement. This makes it possible to avoid continuously performing unnecessary processing.

[0066] FIG. 13 is a diagram showing an example of a message sequence between communication devices 100 in this modification. Operations similar to those in FIG. 5 are assigned the same reference numerals, and descriptions thereof will be omitted. That is, by the processing of F501 to F507, connection processing is performed between the AP 101 and the end STA 111 and between the AP 101 and the relay STA 112, respectively, and information about the end STA 111 is notified from the AP 101 to the relay STA 112. The AP 101 may notify information about the end STAs using a Beacon frame that it periodically transmits (F508). At this time, the Beacon frame may include an End-STA List field 705 containing information about the end STA 111. The end STA 111 then requests the AP 101 to disconnect the connection (F1301). For example, the end STA 111 may request disconnection using a Deauthentication frame. The end STA 111 may request disconnection by transmitting a Disassociation Request frame or the like. When the connection with the end STA 111 is disconnected, the AP 101 updates the information about the STAs it manages. For example, the AP 101 deletes the STA 111 from the list of STAs connected to the AP 101. Meanwhile, the relay STA 112 requests the AP 101 to provide information about the end STAs after a predetermined period has elapsed since transmitting the Relay Request frame (F1302). In response, the AP 101 may notify the AP 101 of the information about the end STAs. At this time, the AP 101 may send a notification that does not include information about the STA 111 (F1303). For example, if there is an end STA other than the STA 111, the AP 101 may send a notification that includes information about the end STA but does not include information about the STA 111. Furthermore, if the end STA no longer exists because STA 111 has disconnected, AP 101 may notify that there is no information about the end STA. For example, AP 101 may transmit a Relay Response frame that does not include the End-STA List field 705. Furthermore, AP 101 may notify that there is no end STA that can perform relay communication by setting the value of 0 in the STA Number field 712.The relay STA 112 updates the information of the end STAs it manages based on the notification from the AP. For example, the relay STA 112 may delete the information of STA 111 from the list of end STAs it manages. In this way, even if the information of the end STAs changes after the connection between the relay STA 112 and the AP 101 is established, the AP 101 may provide the relay STA 112 with information of STAs capable of performing relay communication, and the information managed by the relay STA 112 may be updated. The AP 101 may also announce the updated information of STAs capable of performing relay communication in a beacon frame that it periodically transmits. Since frame exchange using a Relay Request frame, a Relay Response frame, or the like is not required between the AP 101 and the relay STA 112, wireless resources can be used more efficiently.

[0067] As described above, according to this embodiment, a STA operates as a relay STA that relays communication between an AP to which the STA is connected and an end STA. The STA acquires, from the AP, identification information for identifying the end STA. This configuration allows the STA to identify the end STA for which the STA should perform relay. For example, the relay STA identifies the communication quality between the STA and the identified end STA and reports it to the AP. This allows the AP to determine whether or not to perform communication using the relay STA, thereby enabling the relay STA to participate in communication between the AP and the end STA. The STA also acquires, from the AP, capability information and usable communication parameters of the end STA. This configuration allows the STA, when operating as a relay STA, to identify communication parameters to be used between the end STA and the end STA. This enables relaying using appropriate settings, thereby enabling efficient use of wireless resources and improving the reliability of communication between the AP and the end STA. In the above description, an example has been given in which a relay STA uses a Relay Request frame or the like as a frame for requesting information from an end STA, and an AP uses a Relay Response frame or the like to notify information about the end STA. Furthermore, an example has been given in which a UHR Capability element, an End-STA List, or the like is used as the elements and fields used for this purpose. The frames, elements, fields, etc. used to exchange information about the end STA between the AP and the relay STA are not limited to these, and other frames, elements, fields, etc. may be used. For example, a UHR MAC capability element, a Multi Link element, an Extended Capability element, etc. may be used. Furthermore, the names of the frames, elements, fields, etc. used in this embodiment are merely examples and may be referred to by other names. Furthermore, the names relay communication, relay STA, end STA, etc. are merely examples and may be referred to by other names.(Other Embodiments) The present invention can also be realized by supplying a program that implements one or more functions of the above-described embodiments to a system or device via a network or a storage medium, and having one or more processors in the computer of the system or device read and execute the program. It can also be realized by a circuit (e.g., an ASIC) that implements one or more functions. The invention is not limited to the above-described embodiments, and various changes and modifications are possible without departing from the spirit and scope of the invention. Therefore, the following claims are appended to clarify the scope of the invention.

[0068] This application claims priority based on Japanese Patent Application No. 2024-066306, filed April 16, 2024, the entire contents of which are incorporated herein by reference.

Claims

1. A communications device that operates as a station device conforming to the IEEE 802.11 series of standards, comprising: relay means having the function of a first station device that relays communications between a connected access point device and one or more other station devices connected to the access point device; and receiving means that receives from the access point device a predetermined frame containing specific information that identifies a second station device among the one or more other station devices that has a specific capability to communicate with the access point device via relaying by the first station device, wherein the relay means relays communications between the second station device identified by the specific information and the access point device.

2. The communication device according to claim 1, wherein the predetermined frame further includes capability information indicating the predetermined capability possessed by the second station device identified by the identification information.

3. The communication device according to claim 2, wherein the capability information includes at least one of information indicating an ability to transmit frames of a predetermined format used in communication via relay by the first station device and information indicating an ability to receive frames of the predetermined format, and the relay means performs the relay using frames of the predetermined format.

4. The communication device according to claim 3, wherein the frame of the predetermined format is a Trigger frame that reserves radio resources for communication via relay by the first station device and includes information indicating that communication will be via relay by the first station device.

5. The communication device according to any one of claims 1 to 4, wherein the predetermined frame is at least one of a Beacon frame, a Probe Response frame, an Association Response frame, a Reassociation Response frame, a Trigger frame, and an Action frame.

6. A communication device that operates as an access point device compliant with the IEEE 802.11 standard series, comprising: communication means capable of communicating with one or more other station devices connected to the communication device via relaying by a first station device connected to the communication device; identification means for identifying a second station device among the one or more other station devices that has a predetermined capability for communicating with the communication device via relaying by the first station device; and transmission means for transmitting a predetermined frame including identification information for identifying the second station device to the first station device, wherein the communication means communicates with the second station device when communicating via relaying by the first station device.

7. The communication device according to claim 6, wherein the identification means identifies the second station device by acquiring capability information indicating that the second station device has the predetermined capability from each of the one or more station devices.

8. The communication device according to claim 7, wherein the predetermined frame further includes the capability information possessed by the second station device.

9. A communication device as described in claim 7 or 8, wherein the capability information includes at least one of information indicating an ability to transmit frames of a predetermined format used in communication via relay by the first station device and information indicating an ability to receive frames of the predetermined format, and wherein the communication means performs communication with the second station device using frames of the predetermined format.

10. The communication device according to claim 9, wherein the frame of the predetermined format is a Trigger frame that reserves radio resources for communication via relaying by the first station device and includes information indicating that communication will be via relaying by the first station device.

11. The communication device according to any one of claims 6 to 10, wherein the predetermined frame is at least one of a Beacon frame, a Probe Response frame, an Association Response frame, a Reassociation Response frame, a Trigger frame, and an Action frame.

12. A communication method executed by a communication device operating as a station device compliant with the IEEE 802.11 standard series, which has the function of a first station device that relays communications between a connected access point device and one or more other station devices connected to the access point device, and includes receiving from the access point device a predetermined frame containing specific information that identifies a second station device among the one or more other station devices that has a specific capability to communicate with the access point device through relaying by the first station device, and in the relaying, relaying communications between the second station device identified by the specific information and the access point device.

13. A communication method executed by a communication device operating as an access point device compliant with the IEEE 802.11 series of standards, comprising: communicating with one or more other station devices connected to the communication device via relaying by a first station device connected to the communication device; identifying a second station device among the one or more other station devices that has a predetermined capability for communicating with the communication device via relaying by the first station device; and transmitting a predetermined frame including specific information identifying the second station device to the first station device, wherein the communication is communicating with the second station device when communicating via relaying by the first station device.

14. A program for causing a computer to function as each of the means possessed by the communication device according to any one of claims 1 to 11.

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