Communication device, relay method, communication method, and program

Abstract

To efficiently specify a device that can execute relay communication when using relay communication in communication between an access point and a station.SOLUTION: A communication device operating as a station device conforming to the IEEE802.11 series standard has a function as a first station device that relays communication between an access point device in connection and one or more other station devices connected to the access point device, and receives, from the access point device, a predetermined frame including specification information for specifying, from the one or more other station devices, a second station device that has a predetermined capability for communicating with the access point device through the relay provided by the first station device. Relay means executes relay of communication between the second station device specified by the specification information and the access point device.SELECTED DRAWING: Figure 5

Description

[Technical Field]

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

[0002] In recent years, the increase in the amount of data being communicated has led to the development of communication technologies such as wireless local area networks (LANs). 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 the IEEE 802.11a / b / g / n / ac / ax / be standards.

[0003] For the successor to the IEEE 802.11be standard, studies are being conducted with the aim of further improving throughput and expanding communication range. For example, in addition to a communication method in which direct communication is performed between an access point (hereinafter, AP) and a station (hereinafter, STA), a relay communication method using a relay communication device is being considered. Relay communication may also be called relay communication. In relay communication, a STA, which is a relay communication device, 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 series of standards for controlling relay communication. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent Publication No. 2021-72638 Summary of the Invention [Problem to be solved by the invention]

[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. [Means for solving the problem]

[0006] A communication device that operates as a station device compliant with the IEEE802.11 series standard, 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. [Effects of the Invention]

[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. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a diagram illustrating an example of the configuration of a wireless communication system. [Figure 2] FIG. 2 illustrates an example of a hardware configuration of a communication device. [Figure 3] FIG. 2 is a diagram illustrating an example of a functional configuration of an AP. [Figure 4] FIG. 10 is a diagram illustrating an example of the functional configuration of an STA. [Figure 5] FIG. 1 is a diagram illustrating an example of frame exchange performed between communication devices. [Figure 6]FIG. 10 is a diagram illustrating an example of a UHR Capability element. [Figure 7] FIG. 10 is a diagram illustrating an example of an Action frame. [Figure 8] FIG. 10 is a diagram illustrating an example of a UHR Capability element. [Figure 9] 10 is an example of a processing flow executed by an AP. [Figure 10] 10 is an example of a processing flow executed by an STA. [Figure 11] FIG. 1 is a diagram illustrating an example of frame exchange performed between communication devices. [Figure 12] FIG. 1 is a diagram illustrating an example of frame exchange performed between communication devices. [Figure 13] FIG. 1 is a diagram illustrating an example of frame exchange performed between communication devices. DETAILED DESCRIPTION OF THE INVENTION

[0009] 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.

[0010] (System Configuration) FIG. 1 shows an example of the configuration of a wireless communication system according to this embodiment. The wireless communication system includes, for example, an access point (AP) 101 and stations (STAs) 111 and 112. In this embodiment, the STAs 111 and 112 may be collectively referred to as STAs 110. The AP 101 and STAs 110 may be collectively referred to as communication devices 100. The AP 101 and STAs 110 are each communication devices capable of performing wireless communication in accordance with the IEEE 802.11 series standards. 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). The STA 110's participation in the network 131 may be referred to as the STA 110 belonging to the network 131 (or the AP 101). The AP 101 and the STAs 111 are connected using a wireless channel 121. AP 101 and STA 112 are connected using wireless channel 122. STA 111 and STA 112 can also be connected using wireless channel 123. In this example, STA 111 and STA 112 are assumed to be located within the communication range of network 131 established by AP 101. The geographical distance between AP 101 and STA 111 is assumed to be longer than both the distance between AP 101 and STA 112 and the distance between STA 111 and STA 112. For example, STA 112 is assumed to be located between AP 101 and STA 111. While network 131 in FIG. 1 shows a configuration in which one AP 101 and two STAs 110 exist, multiple APs may exist, and 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.

[0011] In this embodiment, the communication device 100 is configured to be able to execute a communication method compliant with a successor standard to IEEE 802.11. 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 that it has functions that realize 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 can execute 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, and the like. The communication device 100 may also support communication standards such as a 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 also be an information processing device, such as a wireless chip, capable of performing wireless communication compliant with the IEEE 802.11bn standard or the like. 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 conforming to the IEEE802.11bn standard or the like. The STA 110 may also be a communication device having an AP function.

[0012] Communication device 100 may communicate using radio signals in frequency bands such as the 2.4 GHz band, 3.6 GHz band, 5 GHz band, and 6 GHz band, as well as the 45 GHz band and 60 GHz band known as millimeter waves. The frequency bands used by communication device 100 are not limited to these and may be, for example, the Sub-1 GHz band. 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 communication device 100 are not limited to these and may be, for example, 240 MHz, 4 MHz, etc.

[0013] The IEEE 802.11 series of standards specifies a function for increasing communication speeds by performing multi-user (MU) communication, in which an AP multiplexes wireless resources to communicate simultaneously with multiple STAs. For example, an AP may 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, or RUs) are allocated to communications between the AP and each STA so that they do not overlap. In OFDMA communication, the carriers used for communications between the AP and each STA are orthogonal on the frequency axis. This configuration utilizing orthogonality on the frequency axis allows the AP to communicate with multiple STAs in parallel within a single specified bandwidth. The AP allocates RUs to each STA. The AP 101 may also 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 different signals are transmitted from each antenna using the same frequency channel. Each STA simultaneously receives the signals transmitted from each antenna, separates the signals, and decodes them. In MIMO communication, the propagation paths used for communication between the AP and each STA are spatially orthogonal. This spatial orthogonality allows the AP to communicate with multiple STAs in parallel within a single specified bandwidth. In this way, by performing multi-user communication, the AP can communicate more data with each STA in the same amount of time than if multi-user communication were not performed.

[0014] Generally, in a communication method conforming to the IEEE 802.11 series of standards, the AP 101 communicates with the STA 110 by directly exchanging wireless frames. 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 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, or the like. That is, when the distance between the communication devices 100 is short, the RSSI and SNR are high, and therefore a highly efficient communication method, such as a modulation method with a high number of modulation levels or a coding method with low redundancy, may be used. 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 signal-to-noise ratio. That is, a STA located far from the AP may use a less efficient communication method, and therefore the communication capacity of the entire network may decrease. 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 the STA 112 relays communication between the AP 101 and the STA 111, the STA 112 is referred to as a relay STA (Relay-STA). Furthermore, the STA 111, which is the communication partner of the AP 101 and is capable of performing relay communication, is referred to as an end STA (End-STA). Note that in this embodiment, the terms "relay," "relay," and "Relay" are interchangeable terms. Performing relay communication between the AP 101 and the end STA 111 via relay by the relay STA 112 may improve efficiency compared to direct communication between the AP 101 and the STA 111. However, unless each communication device is capable of performing relay communication and each communication device mutually knows that the other communication device is capable of performing relay communication, it may not be possible to properly relay communication between the communication devices.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, data transmitted by the relay STA 112 may not be correctly received by the end STA 111. Generally, the STA 111 and the STA 112 each communicate with the AP 101, but do not communicate with each other. Therefore, the STA 112 does not know the capabilities of the STA 111 or the communication parameters that the STA 111 can use. Therefore, the relay STA 112 may not be able to properly relay communication between the AP 101 and the end STA 111.

[0015] In consideration of these circumstances, the STA in this embodiment acquires information about end STAs from the 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 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. 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. 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 to the first STA that includes identification information that identifies the second 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 a predetermined capability possessed by the second STA identified by the identification information. For example, the capability information may be information indicating a capability to transmit frames in a predetermined format used for communication via relaying by the first STA. The capability information may also be information indicating a capability 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.

[0016] The capability that an end STA may have for performing 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 for performing 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 for performing relay communication may be that the end STA instructs a relay STA to relay to an AP. The capability that an end STA may have for performing relay communication may be that the end STA is capable of transmitting using frames in a format for relay communication. The capability that an end STA may have for performing relay communication may be that the end STA is capable of receiving using frames in a format for relay communication. The capability that an end STA may have for performing relay communication may be that the end STA is capable of communicating frames using a frame exchange procedure for relay communication. The capability that an end STA may have for performing 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 the end STA's ability to process 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. Processing frames for relay communication may also include converting the header of a frame for direct communication into a frame format for relay communication, converting a header in a frame format for relay communication into a header for direct communication, etc.

[0017] 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.

[0018] 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 instructions 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 frames 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 frames 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.

[0019] A relay STA may notify the AP of the communication quality between itself and the end STA. Furthermore, a relay STA may notify the end STA of the communication quality between itself and the AP. For example, an 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. Wireless frames may include data frames, management frames, control frames, 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 flows of the AP, end STA, and relay STA are described below.

[0020] (Device configuration) 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.

[0021] 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. In addition to memories such as ROM and RAM, the storage unit 201 may also be configured to include 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.

[0022] 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.

[0023] Furthermore, the control unit 202 controls the functional unit 203 to execute predetermined processes such as communication, image capture, printing, and projection. The functional unit 203 is hardware that enables the communication device 100 to execute 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. Also, for example, if the device is a printer, the functional unit 203 is a print unit that performs print processing. Also, for example, if the device is a projector, the functional unit 203 is a projection unit that performs projection processing.

[0024] 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 a 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.

[0025] The communication unit 206 controls wireless communication compliant with the IEEE 802.11bn standard. The communication unit 206 may also control wireless communication compliant with other IEEE 802.11 series standards, 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. 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. 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 compatible with each communication standard. The communication device 100 communicates data with a partner communication device 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.

[0026] 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.

[0027] (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 for 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 that a communication device generally has, can naturally be included. Furthermore, multiple functional blocks in FIGS. 3 and 4 may be integrated into one functional block, or one functional block may be divided into multiple functional blocks.

[0028] 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 a higher 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. The management frame 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 also be a probe request frame, an association request frame, or a reassociation request frame. The management frame may also be a BA (Block Ack) frame, an action frame, or the like.

[0029] 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.

[0030] 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 STAs and the end STAs, and determines whether to communicate with the end STA via relay by a 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.

[0031] The end STA information notification unit 304 notifies the relay STA of the 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 an STA that can perform relay communication as an end STA. The end STA information notification unit 304 may also notify the relay STA of capability information that indicates the capabilities of the end STA that can perform relay communication. For example, the end STA information notification unit 304 may notify the above specific information and capability information using a Beacon frame, Action frame, etc. that includes an End-STA List field.

[0032] 4 shows an example configuration of the STA 110. The STA 110 may be configured to 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 301, 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 STAs 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 STAs 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 STAs, and notify the respective communication devices of the results. Furthermore, the relay processing unit 403 may analyze a frame in a format for relay communication that the frame transceiver unit 402 receives 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, from the AP, information about end STAs that are capable of relay communication. For example, the end STA information acquisition unit 404 may acquire, from the AP, identification information that identifies the end STA. The end STA information acquisition unit 404 may also 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 identification information and capability information using a Beacon frame, an Action frame, or the like that includes an End-STA List field.

[0033] (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.

[0034] (Connection processing and capability information exchange between AP and end STAs and relay STAs) The AP 101 periodically broadcasts information about the BSS that the AP 101 configures. For example, the AP 101 notifies capability information indicating that the AP 101 is capable of performing relay communication (F501). The AP 101 may notify information about the BSS and capability information using a beacon that it periodically transmits. The AP 101 may notify capability information using a method other than notification using a beacon. For example, the AP 101 may notify capability information using a probe response or the like. The capability information indicating that the AP 101 is capable of performing relay communication may be notified using a UHR Capability element included in a beacon or the like. Note that this embodiment will be described using an example in which the UHR Capability element is used, but the element is not limited to this, 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 that can notify information about the MAC layer. Furthermore, the Multi Link element is an information element that can notify capability information for each link when communication is performed using multiple links.

[0035] When the end STA 111 detects the AP 101, it executes connection processing (F502). For example, the end STA 111 may execute connection processing by transmitting a Probe Request, Association Request, Authentication, etc. 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 relay communication via a Beacon, Probe Response, etc., it may notify the AP 101 of its own capability information during connection processing. For example, the end STA 111 may transmit an Association Request frame including capability information indicating that the end STA is capable of 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 is capable of 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 may confirm that the other party is capable of relay communication.

[0036] When the AP 101 receives an Association Request frame or the like including information indicating the capability information of the end STA 111 (F502), it 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 the other party is capable of performing relay communication.

[0037] When the relay STA 112 detects the AP 101, it executes 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 executed 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 can operate 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 can operate as a relay STA in relay communication.

[0038] When the AP 101 receives an Association Request frame or the like including information indicating the capability information of the relay STA 112 (F505), it 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. As a result, a connection is established 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.

[0039] 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.

[0040] The Relay Transmit Capable field 604 indicates that the communication device that transmitted the wireless frame including this element is capable of transmitting 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, a setting of 1 in this field 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, a setting of 1 in this field 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 receiving 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 data frames transmitted by the end STA 111 via relay by the relay STA 112. As an example, when this field is set to 1, it may indicate that it can receive data frames 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 data frames from the AP 101 via relay by the relay STA. As an example, when this field is set to 1, it may indicate that it can receive data frames from the AP 101 via relay by the relay STA 112. Note that the Relay Transmit Capable field 604 and the Relay Receive Capable field 605 may be integrated. In this case, the integrated single field or single bit indicates that communication using relay communication is possible.In other words, it can indicate that both transmission and reception operations using relay communication are possible. Note that if the ability 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 can be omitted. In other words, 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 that comply with this standard can perform reception operations in relay communication. Therefore, by omitting signaling for required functions and configuring the signaling to notify only optional functions, the number of bits that make up the frame can be reduced.

[0041] The Relay AP Capable field 606 and the Relay STA Capable field 607 indicate that the communication device that transmits the wireless frame containing 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 transmitted by another STA can 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 performed by the AP. Examples of some of the functions performed by the AP include transmitting Beacon frames and processing connections with STAs. That is, functions that should be performed by the AP can 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 communication device that transmits the wireless frame operates as a relay STA but does not perform some of the functions performed by the AP. Note that the ability to operate as a relay STA may be indicated in one field instead of the Relay AP Capable field 606 and the Relay STA Capable field 607. In this case, another field may indicate whether the source STA performs some of the same functions as the AP.

[0042] (Exchange of information about 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.

[0043] 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 an identifier of this Action field in the Protected UHR category. For example, the Protected UHR Action field 702 may be set to a value indicating that it is an Action field related to relay communication. The Dialog 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 Dialog Token field 703. In response to the Relay Request frame, the AP 101 stores the value contained in the received Dialog Token field 703 in the Dialog Token field 703 of the response frame and transmits it. The Relay Control field 704 includes a Relay Action field 711. The Relay Action field 711 indicates a value corresponding to the processing to be performed in relation to 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.

[0044] The Relay Response frame may be one of the UHR Protected Action frames. FIG. 7(B) 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 705. 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 that belong to the AP 101. The End-STA List field 705 may include information about all STAs that belong to the AP 101. In this case, the End-STA List field 705 may include information that can specify 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.

[0045] The End-STA List field 705 may include a STA Number field 711 and one or more STA Info fields 712. The STA Number field 711 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 711 may be set to 2. In this case, there may be two STA Info fields 712 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.

[0046] Each STA Info field 712 contains information about the corresponding end STA. For example, the STA Info field 712 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 712 may also include a Beamformee SS field 724 and a Supported EHT-MCS And NSS Set field 725. The STA Info field 712 further includes a Relay Transmit Capable field 726 and a Relay Receive Capable field 727. The STA Address field 721 indicates information 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 an 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 622 is 0, 1, or 2, a maximum A-MSDU size of 3895 octets, 7991 octets, or 11454 octets may be associated with the field. The Support For 320 MHz field 623 indicates whether the end STA supports the use of a 320 MHz frequency bandwidth. For example, when the value of the Support For 320 MHz field 623 is set to 0, this indicates that the end STA does not support the use of a 320 MHz frequency bandwidth. When the value of the Support For 320 MHz field 623 is set to 1, this indicates that the end STA supports the use of a 320 MHz frequency bandwidth. Note that the Support For 320 MHz field 623 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 the STA supports the use of a 320 MHz frequency bandwidth. The Beamformee SS field 624 indicates the maximum number of spatial streams that the STA can use in beamforming reception processing. The Beamformee SS field 724 may be provided for each frequency bandwidth that the 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 MCS and the number of spatial streams that the STA supports. MCS is an abbreviation for Modulation and Coding Scheme. The Supported EHT-MCS And NSS Set field 725 may be represented by a bitmap. For example, for transmission and reception, a bit associated with a usable MCS may be provided for each number of spatial streams that the STA can use. For example, the value of a bit corresponding to a combination of an MCS and the number of Spatial Streams that the end STA can use 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 that the end STA can use. For example, bitmaps corresponding to 80 MHz, 160 MHz, 320 MHz, etc. may be provided as frequency bandwidths that the end STA can use.

[0047] 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.

[0048] 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 the 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 the End-STA List field 705. In FIG. 8, fields with the same content as those in FIG. 6 and FIG. 7 are assigned the same reference numerals, and their descriptions will be omitted. That is, the UHR Capability element in FIG. 8 includes the End-STA List 705 shown in FIG. 7 based on the configuration in FIG. 6. Note that the predetermined information element may be a UHR Operation element. In this case, the configuration is the same as in Fig. 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 Fig. 8 may be included in a field other than STA Info field 713. For example, it may be included in an element other than the UHR Capability element or the UHR Operation. As an example, each field may be included in any, some, or all of the HT Capability Element, VHT Capability Element, EHT Capability Element, etc. As an example, each field may be included in any, some, or all of the UHR Capability Element, 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 executes relay communication.

[0049] 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 a Beacon frame, the relay STA 112 may identify the STA to which it should relay 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 additional information about the end STA in response to a request from the relay STA 112. This enables efficient use of wireless 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. Furthermore, the Relay Request frame transmitted by the relay STA 112 may 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.

[0050] (Determining whether to perform relay communication in AP) Before communicating 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 the AP 101 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 the AP 101 and the end STA using a frame transmitted from the AP 101, such as a Beacon frame. The relay STA 112 may also measure the communication quality between the AP 101 and the end STA using a frame transmitted by the identified end STA. The relay STA 112 may measure communication quality based on a request from the AP 101 and report the results to the AP 101 and the end STA 111. Information indicating 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.

[0051] 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 the targets of the communication quality measurement, identification information for identifying the communication devices that were the 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 regarding the AP 101 and the end STA 111, the number of communication devices that were the targets of the communication quality measurement may be two. If the relay STA 112 generates an SNR Notify frame for each communication device, the number of communication devices that were the targets of the communication quality measurement may be one. In this case, the field indicating the number of communication devices that were the targets of the communication quality measurement may be omitted. Furthermore, if the number of communication devices targeted for communication quality measurement is two or more, subsequent fields may be provided for each of the communication devices. For example, identification information for identifying the communication devices targeted for communication quality measurement may include the MAC addresses, BSSIDs, AIDs, etc. of the AP 101 and the end STA 111. Furthermore, information indicating the communication quality as a measurement result may include information indicating the SNR, RSSI, etc. of the frame received from the AP 101 and the SNR, RSSI, etc. of the 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 an SNR Notify frame, and may include, for example, a Null Data Packet or a CSI Report frame. CSI is an abbreviation for Channel Status Information.

[0052] 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 the 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. As an 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. 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, and 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 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.

[0053] (Data frame communication processing via 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 required 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 required 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 BlockACK to be returned from the end STA 111. In this case, in addition to the above periods, the Duration field may be set to 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. The Duration field may be set to other periods without being limited to these, and may be set to a period required for the procedure for performing relay communication, which will be described later. In this way, relay communication may be performed using the period secured by the Trigger frame.

[0054] 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 may be received by the relay STA 112 and transmitted by the relay STA 112 to the end STA 111. 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, the relay STA 112 may transmit another Trigger frame indicating that relay communication will be performed to the end STA 111 in response to receiving the Trigger frame. 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 Trigger frame transmitted 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 may transmit the data frame received from the AP 101 to the end STA 111. This allows for more efficient use of wireless resources than when Trigger frames are transmitted separately from the AP 101 and the relay STA 112. Note that the Trigger frame may notify the frequency resources to be used in relay communication.For example, the Trigger frame may include information indicating the RU to be used when transmitting a data frame from the AP 101 to the relay STA 112, and information indicating the 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 the period required for relay communication is set, and may reserve the period required for relay communication by receiving a CTS frame in response to this. In addition, the RTS frame may be used to notify information indicating that relay communication will be performed.

[0055] Furthermore, the AP 101 may perform relay communication using a data frame in a format 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 the 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 in the same format with the destination changed to the end STA 111. The relay STA 112 may also generate and transmit a data frame in a format 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 itself. The AP 101 may also transmit a data frame for relay communication that includes information that can identify each of the relay STA and the end STA, and information indicating that the data frame is for relay communication. In this case, the relay STA 112 may transmit the received data frame as is to the end STA 111. The end STA 111 may perform reception processing for the received data frame based on the information indicating that the data format is for relay communication.

[0056] 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 it has stored data, in order to determine whether there is data to transmit 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 a data frame. The end STA 111 can transmit a data frame based on the instruction from the Trigger frame. The end STA 111 can transmit the data frame using a data frame in the above-mentioned relay communication format.

[0057] (Processing flow in AP101) The following describes the operation when the AP 101 notifies the relay STA 112 of end STA information. FIG. 9 shows an example of a processing flow when the AP 101 notifies the relay STA 112 of end STA information. 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 a 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 end STA information (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 determines that there has been no request for end STA information (NO in S902), the AP 101 ends this processing. On the other hand, when there is a request for information about end STAs (YES in S902), the AP 101 determines whether or not it manages information about end STAs (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 that can perform relay communication among the STAs connected to the AP 101. If it determines that it does not have information about end STAs it manages (NO in S903), the AP 101 notifies the relay STA 112 that it does not manage information about them (S907) and ends this process. On the other hand, if the AP 101 has information about end STAs it manages (YES in S903), it notifies the relay STA 112 of the information about the end STAs (S904). The information about the end STAs notified from the AP 101 may be information that can identify the end STAs, communication parameters that the end STAs can use for relay communication, etc. Then, the AP 101 determines whether or not information on communication quality related to the AP itself and the end STAs has been acquired from the relay STA 112 (S905). If information on 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), AP 101 stores the information and ends this process. In this way, AP 101 can notify the relay STA 112 of the information regarding the end STAs. Based on the information regarding the end STAs acquired from AP 101, the relay STA 112 can identify the communication quality between itself and the end STAs and provide it to AP 101. Furthermore, based on the information regarding communication quality provided by the relay STA 112, AP 101 can select whether or not to perform communication via relay of the relay STA 112. Furthermore, the relay STA 112 can relay communication between AP 101 and the end STAs using communication parameters and the like usable by the end STAs acquired from AP 101.

[0058] (Processing flow in STA112) The following describes the operation of the STA 112 when it acquires information about the end STAs from the AP 101. FIG. 10 shows an example of a processing flow when the STA 112 acquires information about the end STAs 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 100 (S1001). The STA 112 may request the provision of information about the end STAs 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 STAs (NO in S1003), it terminates this processing. On the other hand, if the STA 112 has acquired the information of the end STA (YES in S1003), it stores the information of the end STA (S1004). Then, the STA 112 identifies the communication quality between the STA itself and the AP 102 and between the end STA itself and each of the end STAs based on the acquired information of the end STAs (S1005). The STA 112 notifies the AP 101 and the end STAs of information indicating the identified communication quality (S1006). In this way, the STA 112 can identify, for example, the communication quality between the STA itself and the identified end STA 111 based on the information of 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 through relay by the STA 112, using the STA 112 as a relay STA, and can execute communication 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 usable by the end STA 111 acquired from the AP 101.

[0059] (Variation 1) In the above processing example, the relay STA 112 transmits a Relay Request frame to acquire information about the end STAs, and the AP 101 responds by transmitting a Relay Response frame. In this modification, 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 to this, the AP 101 notifies the AP 101 of information about the end STAs that can perform relay communication in an Association Response frame. With this configuration, the provision of information about the end STAs 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 wireless resources to be used efficiently.

[0060] FIG. 11 is a diagram showing an example of a message sequence between communication devices 100 in this modification. In FIG. 11, the same operations as those in FIG. 5 are assigned the same reference numerals, and description thereof will be omitted. First, a connection process is executed 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 party can confirm that the other party is capable of performing relay communication. Next, a connection process is executed between the AP 101 and the relay STA 112 (F504, F1101). At this time, the relay STA 112 notifies the other party that it can operate as a relay STA in relay communication in an Association Request frame (F504). For example, the relay STA 112 can make this notification using the Relay AP Capable field 606 or the Relay STA Capable field 607 of the UHR Capability element shown in FIG. 6. Upon receiving the Association Request frame, the AP 101 transmits an Association Response frame. At this time, when the AP 101 determines that the relay STA 112 has the capability to operate as a relay STA, it notifies the AP 101 of the information of the end STAs using an Association Response frame. For example, the AP 101 may notify the relay STA 112 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, the AP 101 may provide the relay STA 112 with information about the end STAs. 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. The relay STA 112 may also notify the AP 101 of its capability to operate as a relay STA for relay communication using another frame.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 an 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 fact that the relay STA 112 can operate as a relay STA capable of performing some of the functions performed by an AP may be notified by a Relay AP Capable field 606 included in a UHR Capability element, or the like. 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, and may 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.

[0061] (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 modified example, a case where the AP 101 establishes a connection with the relay STA 112 and then establishes a connection with the end STA 111 will be 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. After the connection is established, information about the end STA to provide becomes available. Therefore, after the connection with the AP 101 is established, 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.

[0062] FIG. 12 is a diagram showing an example of a message sequence between the 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. First, a connection process is executed 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 there are no STAs connected to the AP 101 other than the relay STA 112, the AP 101 can send a notification indicating that there are no end STAs (F507). For example, the AP 101 can send a Relay Response frame that does not include the End-STA List field 705. The method by which the AP 101 sends a notification indicating that there are no end STAs is not limited to this. For example, the AP 101 may notify that there are no end STAs 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 are no other end STAs capable of performing relay communication based on the fact that the Relay Response frame contains only its own information.

[0063] Next, connection processing is performed between the AP 101 and the end STA 111 (F502, F503). As a result, a connection is established between the AP 101 and the end STA 111, and each can confirm that the other 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 STAs (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 STAs to the relay STA 112. Note that the AP 101 may broadcast information about the end STAs in a Beacon frame that it periodically transmits. In this case, the relay STA 112 can obtain information about STAs that are capable of performing 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, etc. between the AP 101 and the relay STA 112 is not required, wireless resources can be used effectively.

[0064] (Variation 3) In this modification, 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.

[0065] FIG. 13 is a diagram showing an example of a message sequence between the communication devices 100 in this modification. Operations similar to those in FIG. 5 are assigned the same reference numerals, and description 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 transmits periodically (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. Note that the end STA 111 may request disconnection by transmitting a Disassociation Request frame or the like. When the AP 101 disconnects from the end STA 111, 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, when a predetermined period of time has elapsed since the relay STA 112 transmitted the Relay Request frame, the relay STA 112 requests the AP 101 to provide information about the end STAs (F1302). In response to this, the AP 101 may notify the AP 101 of the information about the end STAs. At this time, the AP 101 may transmit a notification that does not include information about the STA 111 (F1303). For example, if there are end STAs other than the STA 111, the AP 101 may transmit a notification that includes information about the end STAs but does not include information about the STA 111. Furthermore, if the end STA no longer exists because the STA 111 has disconnected, the AP 101 may notify the AP 101 that there is no information about the end STAs. For example, the AP 101 may transmit a Relay Response frame that does not include the End-STA List field 705. In addition, the AP 101 can 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 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 that can perform 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 that can perform 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 efficiently.

[0066] 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 relay communication. 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 communication should be performed 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 to identify communication parameters to be used between the end STA and the STA when operating as a relay 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. The above description uses an example in which a relay STA uses a Relay Request frame or the like to request information from the end STA, and an AP uses a Relay Response frame or the like to notify the end STA of information. Also, an example has been described in which a UHR Capability element, an End-STA List, etc. are used as elements and fields used for this purpose. The frames, elements, fields, etc. used to exchange end STA information 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, etc. may be used. Also, the names of the frames, elements, fields, etc. used in this embodiment are examples and may be called by other names. Furthermore, the names relay communication, relay STA, end STA, etc. are examples and may be called by other names.

[0067] The present invention can also be realized by supplying a program that realizes 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., ASIC) that realizes one or more functions.

[0068] (Summary of the embodiment) At least some of the above-described embodiments can be summarized as follows. (Item 1) A communication device that operates as a station device conforming to the IEEE 802.11 series standard, a relay means having a function as a first station device for relaying communication between a connected access point device and one or more other station devices connected to the access point device; receiving means for receiving from the access point device a predetermined frame including identification information for identifying a second station device among the one or more other station devices, the second station device having a predetermined capability for communicating with the access point device via relay by the first station device; The relay means relays communication between the second station device identified by the identification information and the access point device. A communication device comprising: (Item 2) The predetermined frame further includes capability information indicating the predetermined capability of the second station device identified by the identification information. 2. The communication device according to item 1, (Item 3) the capability information includes at least one of information indicating a capability to transmit frames in a predetermined format used in communication via relay by the first station device and information indicating a capability to receive frames in the predetermined format; The relay means executes the relay using frames of the predetermined format. 3. The communication device according to item 2. (Item 4) The frame of the predetermined format is a Trigger frame including information indicating that wireless resources for communication via relay by the first station device are reserved and that communication is to be performed via relay by the first station device. 4. The communication device according to item 3, (Item 5) 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. 5. The communication device according to any one of items 1 to 4, (Item 6) A communication device that operates as an access point device conforming to the IEEE 802.11 series standard, a communication means capable of communicating with one or more other station devices connected to the communication device via a relay by a first station device connected to the communication device; a means for identifying a second station device among the one or more other station devices, the second station device having a predetermined capability for communicating with the communication device via relaying by the first station device; a transmitting means for transmitting a predetermined frame including identification information for identifying the second station device to the first station device; When the communication means communicates via the relay of the first station device, the communication means communicates with the second station device. A communication device comprising: (Item 7) The identifying 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. 7. The communication device according to item 6, (Item 8) The predetermined frame further includes the capability information of the second station device. 8. The communication device according to item 7, (Item 9) the capability information includes at least one of information indicating a capability to transmit frames in a predetermined format used in communication via relay by the first station device and information indicating a capability to receive frames in the predetermined format; The communication means communicates with the second station device using frames in the predetermined format. 9. The communication device according to item 7 or 8, (Item 10) The frame of the predetermined format is a Trigger frame including information indicating that wireless resources for communication via relay by the first station device are reserved and that communication is to be performed via relay by the first station device. 10. The communication device according to item 9, (Item 11) 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. 11. The communication device according to any one of items 6 to 10. (Item 12) A communication method executed by a communication device operating as a station device conforming to the IEEE 802.11 series standard, comprising: a relay step of functioning as a first station device to relay communication between the currently connected access point device and one or more other station devices connected to the currently connected access point device; a receiving step of receiving from the access point device a predetermined frame including identification information that identifies a second station device, among the one or more other station devices, that has a predetermined capability for communicating with the access point device via relay by the first station device; The relaying step relays communication between the second station device identified by the identification information and the access point device. A relay method characterized by: (Item 13) A communication method executed by a communication device operating as an access point device conforming to the IEEE 802.11 series standard, comprising: a communication step for enabling communication with one or more other station devices connected to the communication device via a relay by a first station device connected to the communication device; a step of identifying a second station device among the one or more other station devices, the second station device having a predetermined capability for communicating with the communication device via relay by the first station device; a transmitting step of transmitting a predetermined frame including identification information for identifying the second station device to the first station device; The communication step includes performing communication with the second station device when the communication is performed via a relay by the first station device. A communication method comprising: (Item 14) 12. A program for causing a computer to function as each of the means possessed by the communication device according to any one of items 1 to 11.

[0069] The invention is not limited to the above-described embodiments, and various changes and modifications can be made without departing from the spirit and scope of the invention. Accordingly, the following claims are appended to apprise the public of the scope of the invention. [Explanation of symbols]

[0070] 101:AP, 111:STA, 112:STA

Claims

1. A communication device that operates as a station device conforming to the IEEE 802.11 series standard, a relay means having a function as a first station device for relaying communication between a connected access point device and one or more other station devices connected to the access point device; receiving means for receiving from the access point device a predetermined frame including identification information for identifying a second station device among the one or more other station devices, the second station device having a predetermined capability for communicating with the access point device via relay by the first station device; The relay means relays communication between the second station device identified by the identification information and the access point device. A communication device comprising:

2. The predetermined frame further includes capability information indicating the predetermined capability of the second station device identified by the identification information.

2. The communication device according to claim 1.

3. the capability information includes at least one of information indicating a capability to transmit frames in a predetermined format used in communication via relay by the first station device and information indicating a capability to receive frames in the predetermined format; The relay means executes the relay using frames of the predetermined format.

3. The communication device according to claim 2.

4. The frame of the predetermined format is a Trigger frame that reserves wireless resources for communication via relay by the first station device and includes information indicating that communication will be performed via relay by the first station device.

4. The communication device according to claim 3.

5. 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.

2. The communication device according to claim 1.

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

7. The identifying 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.

7. The communication device according to claim 6.

8. The predetermined frame further includes the capability information of the second station device.

8. The communication device according to claim 7,

9. the capability information includes at least one of information indicating a capability to transmit frames in a predetermined format used in communication via relay by the first station device and information indicating a capability to receive frames in the predetermined format; The communication means communicates with the second station device using frames in the predetermined format.

8. The communication device according to claim 7,

10. The frame of the predetermined format is a Trigger frame that reserves wireless resources for communication via relay by the first station device and includes information indicating that communication will be performed via relay by the first station device.

10. The communication device according to claim 9.

11. 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.

7. The communication device according to claim 6.

12. A communication method performed by a communication device operating as a station device conforming to the IEEE 802.11 series standard, comprising: a relay step of functioning as a first station device that relays communication between the currently connected access point device and one or more other station devices connected to the currently connected access point device; a receiving step of receiving from the access point device a predetermined frame including identification information that identifies a second station device, among the one or more other station devices, that has a predetermined capability for communicating with the access point device via relay by the first station device; The relay step relays communication between the second station device identified by the identification information and the access point device. A relay method characterized by:

13. A communication method executed by a communication device operating as an access point device conforming to the IEEE 802.11 series standard, comprising: a communication step for enabling communication with one or more other station devices connected to the communication device via a relay by a first station device connected to the communication device; a step of identifying a second station device among the one or more other station devices, the second station device having a predetermined capability for communicating with the communication device via relay by the first station device; a transmitting step of transmitting a predetermined frame including identification information for identifying the second station device to the first station device; The communication step includes the step of communicating with the second station device when the communication is performed via a relay by the first station device. A communication method comprising:

14. A program for causing a computer to function as each of the means included in the communication device according to claim 1.

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