Communication device, communication method, and program

Abstract

To provide a communication device and a communication method that flexibly implement the use of OFDMA in communication between an access point and a station.SOLUTION: In a wireless communication system, a communication device that communicates with another communication device communicates data frames by selectively using a first communication method in which radio resources are allocated using at least two or more first-type resource units (RUs) each consisting of a plurality of subcarriers arranged so that at least some of the subcarriers are discontinuous on a frequency axis, and data is communicated by orthogonal frequency division multiple access (OFDMA) using the radio resources, and a second communication method in which radio resources are allocated using at least two or more second-type RUs, each consisting of a plurality of subcarriers arranged contiguously on the frequency axis, and the data is communicated by the OFDMA using the radio resources.SELECTED DRAWING: Figure 14

Description

[Technical Field]

[0001] The present invention relates to a technology for performing wireless communication using Orthogonal Frequency Division Multiple Access (OFDMA) that conforms to the IEEE 802.11 standard. [Background technology]

[0002] In recent years, the increasing volume of data being transmitted has led to the development of communication technologies such as wireless local area networks (WLANs). The IEEE (Institute of Electrical and Electronics Engineers) 802.11 standard series is known as the main WLAN communication standard. The IEEE 802.11 standard series includes IEEE 802.11a / b / g / n / ac / ax / be standards. To further improve communication reliability, the IEEE 802.11bn standard is being developed as the successor to the IEEE 802.11be standard. The IEEE 802.11 Working Group (WG), which is formulating the IEEE 802.11bn standard, is defining the goals and scope of the standard in the UHR SG, and the TGbn will specify the detailed technical content to be included in the standard. UHR SG stands for Ultra High Reliability Study Group. TGbn is also an abbreviation for Task Group bn.

[0003] The IEEE802.11 series of standards uses the Orthogonal Frequency Division Multiple Access (OFDMA) method to improve throughput and frequency utilization efficiency. OFDMA is an abbreviation for Orthogonal Frequency Division Multiple Access. In OFDMA, for example, the frequency channel used between communication devices is divided on the frequency axis to form multiple units. Each unit is called a Resource Unit (RU). An access point (AP) assigns each RU to each station (STA), allowing communication between the AP and multiple STAs to take place in parallel. This improves frequency utilization efficiency for the entire communication system.

[0004] Meanwhile, in recent years, many countries have been developing legal regulations to allow wireless LANs to use frequencies in the 6 GHz band. The availability of frequencies in the 6 GHz band will further improve wireless LAN throughput. However, the legally permitted value for transmission power density required when using the 6 GHz band is smaller than that of the 2.4 GHz and 5 GHz bands, which are frequency bands traditionally used in wireless LANs. Therefore, in formulating the IEEE 802.11bn standard, technologies are being considered to increase transmission power while satisfying the legally permitted value for transmission power density when using the 6 GHz band. For example, Non-Patent Document 1 considers an OFDMA system that allocates wireless resources using RUs consisting of multiple subcarriers arranged so that at least some of the subcarriers are discontinuous on the frequency axis. Such RUs may be called Distributed Resource Units (DRUs). [Prior art documents] [Non-patent literature]

[0005] [Non-Patent Document 1] Lin Yang et al., “High Level Thoughts on DUR Design (IEEE 802.11-23 / 1988r1),” IEEE802.11, 2024. Summary of the Invention [Problem to be solved by the invention]

[0006] One aspect of the present invention provides a technique that allows the flexible use of OFDMA in communications between access points and stations. [Means for solving the problem]

[0007] A communication device that performs communication with another communication device in accordance with the IEEE802.11 series standard includes a communication means capable of performing communication using a first communication method in which wireless resources are allocated using at least two or more first-type resource units (RUs), each RU being made up of a plurality of subcarriers that are arranged so that at least some of the subcarriers are discontinuous on a frequency axis, and data is communicated by orthogonal frequency division multiple access (OFDMA) using the wireless resources, and a second communication method in which wireless resources are allocated using at least two or more second-type RUs, each RU being made up of a plurality of subcarriers that are arranged so that they are contiguous on a frequency axis, and data is communicated by OFDMA using the wireless resources, When communicating data frames using the first communication method, a predetermined frame having a specific value set therein indicating that the first communication method will be used is transmitted to the other communication device, thereby indicating to the other communication device that the first communication method will be used; when communicating data frames with the other communication device using the second communication method, a predetermined frame not having the specific value set therein is transmitted to the other communication device, thereby indicating to the other communication device that the second communication method will be used; after transmitting the predetermined frame, communication of data frames with the other communication device is performed using the communication method indicated by the predetermined frame. [Effects of the Invention]

[0008] One aspect of the present invention allows for flexibility in the use of OFDMA in communications between access points and stations. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a diagram illustrating an example of the configuration of a wireless communication system. [Figure 2] FIG. 1 is a diagram illustrating an example of an arrangement pattern of RUs on the frequency axis in OFDMA. [Figure 3] FIG. 1 is a diagram illustrating an example of the correspondence between RU indexes and subcarrier indexes in OFDMA. [Figure 4] FIG. 1 is a diagram illustrating the concept of OFDMA using DRU. [Figure 5] FIG. 10 is a diagram showing an example of the correspondence between subcarrier indexes in a CRU and subcarrier indexes in a DRU. [Figure 6] FIG. 10 is a diagram showing an example of the correspondence between RU indexes and subcarrier indexes in OFDMA using DRUs. [Figure 7] A figure showing an example of a method for arranging DRUs in a PPDU with a bandwidth of 160 MHz by repeating the arrangement pattern of DRUs corresponding to a PPDU with a bandwidth of 80 MHz on the frequency axis. [Figure 8] FIG. 1 is a diagram illustrating an example of frame exchange performed between communication devices. [Figure 9] FIG. 10 is a diagram illustrating an example of the configuration of a Trigger frame. [Figure 10] FIG. 10 is a diagram illustrating an example of the configuration of a User Info subfield. [Figure 11] FIG. 10 is a diagram illustrating an example of the configuration of a User Info subfield. [Figure 12] FIG. 2 illustrates an example of a hardware configuration of a communication device. [Figure 13] FIG. 2 illustrates an example of a functional configuration of a communication device. [Figure 14] FIG. 10 is a diagram illustrating an example of a processing flow executed by an AP. [Figure 15] FIG. 10 is a diagram illustrating an example of a processing flow executed by an STA. DETAILED DESCRIPTION OF THE INVENTION

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

[0011] (System Configuration) FIG. 1 shows an example 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 to 113. The AP may also be called an AP STA. The STAs may also be called non-AP STAs. In this embodiment, the STAs 111 to 113 may be collectively referred to as STA 110. The AP 101 and the STAs 110 may also be collectively referred to as communication devices 100. The AP 101 and the 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 to 113 participate in a network 131 established by the AP 101. The AP 101 and the STA 111 are connected using a wireless channel 121. The AP 101 and the STA 112 are connected using a wireless channel 122. Furthermore, AP 101 and STA 113 are connected using wireless channel 123. Wireless channels 121 to 123 use the same frequency. Although network 131 in FIG. 1 shows a configuration in which one AP 101 and three STAs 110 exist, there may be multiple APs, one or two STAs 110, or four or more STAs 110. In this case, multiple STAs may be connected to one AP, or one STA may be connected to multiple APs.

[0012] In this embodiment, the communication device 100 is configured to be able to execute a communication method compliant with a successor standard to 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 achieve highly reliable communication, low latency communication, improved throughput when communication traffic is congested, and reduced power consumption in APs. The IEEE 802.11bn standard may also be referred to as the UHR standard. UHR is an abbreviation for Ultra High Reliability. The communication device 100 may execute a communication method compliant with a successor standard to the IEEE 802.11bn standard. A wireless frame used in communication between communication devices 100 compliant with this successor standard may be referred to as a UHR PPDU. PPDU is an abbreviation for Physical Layer Protocol Data Unit. The term UHR was established for convenience, taking into account the goals of the standard and the distinctive features defined in the standard. In other words, a different name may be assigned to this standard once the standard development work is completed. Similarly, the term IEEE 802.11bn may be assigned a different name once the standard development work is completed. It should be noted that this specification and the appended claims are essentially applicable to all successor standards to the IEEE 802.11be standard, including these cases.

[0013] The communication device 100 may also be compatible with at least one of legacy standards that predate the IEEE 802.11bn standard. That is, the communication device 100 can communicate using PPDUs of the legacy standards. Examples of legacy standards include the IEEE 802.11a / b / g / n / ac / ax / be standards. The communication device 100 may also be compatible with 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 be configured to support cellular wireless communication, such as 5G and LTE. 5G is an abbreviation for the fifth generation mobile communication system. LTE is an abbreviation for Long Term Evolution. The communication device 100 may also be compatible with a communication standard 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 STA 110 may be, for example, a camera, a tablet, a smartphone, a PC, a mobile phone, a video camera, a wearable device such as smart glasses, or an HMD (head-mounted display), but is not limited to these. The STA 110 may also be an IoT device such as an IoT (Internet of Things) sensor, a smart lock, or a smart sensor. The IoT sensor may be an acceleration sensor, a light sensor, a humidity sensor, or the like. The AP 101 or the STA 110 may be an information processing device such as a wireless chip that complies with the IEEE 802.11bn standard or the like and is capable of transmitting and receiving UHR PPDUs. In this case, various controls may be performed by a hardware circuit within the wireless chip. It is also possible to configure various processes to be performed by a processor, memory, or hardware circuit such as an ASIP within the wireless chip working together. ASIP stands for Application-Specific Instruction Set Processor.

[0014] The communication device 100 may communicate using radio signals in frequency bands such as the 2.4 GHz band, the 3.6 GHz band, the 5 GHz band, the 6 GHz band, and the 45 GHz band and 60 GHz band known as millimeter waves. The frequency bands used by the communication device 100 are not limited to these and may be, for example, the sub-1 GHz band. The communication device 100 may also communicate using frequency channels with bandwidths of 20 MHz, 40 MHz, 80 MHz, 160 MHz, 320 MHz, 540 MHz, 640 MHz, 1080 MHz, and 2160 MHz. The bandwidths used by the communication device 100 are not limited to these and may be, for example, 240 MHz or 4 MHz. A 40 MHz frequency channel may be formed by combining two 20 MHz frequency channels. An 80 MHz frequency channel may be formed by combining two 40 MHz frequency channels. An 80 MHz frequency channel may be formed by combining four 20 MHz frequency channels. Similarly, 160 MHz, 320 MHz, etc. frequency channels may be formed by combining or combining multiple channels of each narrower frequency band.

[0015] The IEEE 802.11 series of standards specifies a function for increasing communication speed by performing multi-user (MU) communication, in which an AP multiplexes wireless resources with multiple STAs for simultaneous communication. For example, an AP may communicate with multiple STAs in parallel using OFDMA. OFDMA is an abbreviation for Orthogonal Frequency Division Multiple Access. In OFDMA, the data field of a PPDU transmitted using a frequency channel with a predetermined bandwidth is divided into multiple units on the frequency axis. The predetermined bandwidth may be 20 MHz, 40 MHz, 80 MHz, 160 MHz, 320 MHz, etc. Each of the multiple units is called a resource unit (RU). Each RU may be assigned to a different STA. The AP and one or more STAs may communicate in parallel using the RUs assigned to each STA. This allows multi-user communication to be performed. Note that one RU may be assigned to a group of STAs. 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.

[0016] The data field included in the PPDU is composed of one or more Orthogonal Frequency Division Multiplexing (OFDM) symbols. Each OFDM symbol is composed of multiple subcarriers. A subcarrier is also called a tone or subcarrier. For example, one OFDM symbol with an 80 MHz bandwidth may be composed of 1,024 subcarriers. In this case, each subcarrier may be spaced at 78.125 kHz intervals. In OFDMA, one RU is formed by multiple grouped subcarriers. Multiple types of RUs may be configured based on the number of subcarriers that make up the RU. For example, possible RU types include 26-tone RU, 52-tone RU, 106-tone RU, 242-tone RU, 484-tone RU, and 996-tone RU. The number of subcarriers that make up each RU type (RU type) may be 26, 52, 106, 242, 484, or 996, respectively. In this way, the number of subcarriers constituting an RU can be indicated by the RU type. Figure 2 shows an example of an RU allocation pattern when RUs of each RU type are allocated on the frequency axis in a PPDU composed of OFDM symbols with an 80 MHz bandwidth. Note that in the following description, a PPDU composed of OFDMA symbols with a predetermined bandwidth may be simply referred to as a PPDU of a predetermined bandwidth. In Figure 2, the horizontal axis represents frequency. For example, as an RU allocation pattern on the frequency axis, for a 26-tone RU, 37 RUs can be allocated on the frequency axis. Furthermore, for 52-tone RUs, 106-tone RUs, 242-tone RUs, 484-tone RUs, and 996-tone RUs, 16, 8, 4, 2, and 1 RU can be allocated, respectively. As such, different RU types have different numbers of subcarriers constituting one RU, and therefore different numbers of RUs can be allocated in a PPDU with the same bandwidth. In one PPDU, each RU can be identified by its RU type and RU index. For example, in an RU type of 26-tone RU in an 80 MHz bandwidth, each RU can be assigned an RU index of 1 to 37.For example, the RU index may indicate the position of each RU on the frequency axis. While Figure 2 shows an example in which one or more RUs of the same RU type are arranged on the frequency axis, in actual OFDMA, multiple RUs of different RU types may be arranged so as not to overlap on the frequency axis. For example, RU indexes 1 and 2 for 26-tone RUs, RU index 2 for a 52-tone RU, and RU index 2 for a 106-tone RU may constitute one PPDU.

[0017] Each subcarrier included in an OFDM symbol constituting a PPDU can be identified by a subcarrier index. In the case of an 80 MHz bandwidth, for example, an integer ranging from -512 to 511 can be assigned as a subcarrier index to each of 1,024 subcarriers. FIG. 3 shows an example of the relationship between RU type, RU index, and subcarrier index. For example, the subcarrier index of the subcarrier at the center frequency on the frequency axis in a frequency band occupied by one OFDM symbol is set to 0, and subcarriers at lower frequencies are assigned negative indexes, with the absolute value increasing as the frequency decreases. On the other hand, subcarriers at frequencies higher than the center frequency are assigned positive indexes, with the absolute value increasing as the frequency increases. Note that the absolute value of the difference in index between adjacent subcarriers can be 1. FIG. 3 shows an example in which RUs with small RU index values ​​are configured using subcarriers with small subcarrier index values, and RUs with large RU index values ​​are configured using subcarriers with large subcarrier index values. In this way, when a specific RU is specified using the RU type and RU index, the subcarrier indexes that make up that specific RU are determined. For example, the subcarrier indexes that make up RU1 of a 26-tone RU range from -449 to -474. Thus, for example, when AP 101 specifies the RU type and RU index, STA 110 can identify the subcarrier index from the specified RU type and RU index and communicate using that subcarrier. RU 19 indicates a Middle-26 Tone RU.

[0018] Subcarriers may include data subcarriers used for data transmission, pilot subcarriers used for pilot signal transmission, and unused subcarriers not used for any transmission. Unused subcarriers may include DC subcarriers, which are subcarriers of a direct current (DC) component and its neighboring subcarriers, guard band subcarriers at the edge of the frequency band occupied by the PPDU, and null subcarriers that are neither of these. For example, the subcarrier indices constituting RU19 of a 26-tone RU range from -16 to -4 and from 4 to 16. This RU is arranged across the DC subcarrier, and therefore may include the DC subcarrier. For example, null subcarriers may be arranged between adjacent RUs. The bandwidth of PPDUs communicated between communication devices 100 is not limited to 80 MHz. For example, PPDUs with bandwidths of 20 MHz, 40 MHz, 160 MHz, 320 MHz, etc. may be communicated. In these cases, subcarriers and RUs may be arranged on the frequency axis according to the respective bandwidths. The RU types, RU indices, and subcarrier indices applicable to each bandwidth may be predefined in the same way as for the 80 MHz bandwidth. For example, even if the PPDU bandwidth is different, the number of subcarriers constituting each allocated RU may be the same. That is, even if the PPDU bandwidth is different, the RU type used may be the same. In this case, the range of subcarrier indices assigned to each subcarrier may differ depending on the PPDU bandwidth. Furthermore, the range of RU indices assigned to each RU may differ. As a result, the correspondence between RU indices and subcarrier indices may differ from that shown in FIG. 3. In this case, for example, the RU types, RU indices, and subcarrier indices corresponding to each PPDU bandwidth in the IEEE 802.11 series standards may be used.

[0019] As described above, when an RU used in OFDMA is configured with contiguous subcarriers on the frequency axis, this RU may be called a Consecutive Resource Unit (CRU). A CRU may also be called a contiguous RU or a regular RU (rRU). A CRU may include multiple data subcarriers, pilot subcarriers, and unused subcarriers that are contiguous on the frequency axis. Exceptionally, RU19, which is the Middle-26 Tone of the CRU, may include a first data subcarrier group of 13 contiguous tones and a second data subcarrier group of 13 contiguous tones in a frequency region that is not contiguous with but close to the first data subcarrier group. Here, OFDMA using a CRU generally can achieve a high transmit power density. Transmit power density is the transmit power per unit frequency. That is, because OFDMA using a CRU uses contiguous subcarriers on the frequency axis, transmit power is concentrated in a specified bandwidth, resulting in a high transmit power density. On the other hand, because legal limits for transmit power density are set by each country, transmissions cannot be performed at power levels exceeding those limits. For example, because the transmit power density limit is set low in the 6 GHz band, when performing OFDMA communications using a CRU in the 6 GHz band, the transmit power of each subcarrier may be low. This may result in difficulty in transmitting signals to STAs located far from the AP. In response to this, distributing the subcarriers constituting an RU across a wide band may increase the transmit power of each subcarrier. For example, while maintaining the number of subcarriers constituting each RU, OFDMA communications may be performed using an RU configured with subcarriers, at least some of which are not contiguous on the frequency axis, and arranged across a wider frequency band than a conventional CRU. An RU configured in this way may be called a Distributed RU (DRU). A DRU may also be called a Distributed RU, Enhanced RU, or the like. Note that contiguous subcarriers on the frequency axis may refer to subcarriers whose subcarrier indices are contiguous among the subcarriers included in the OFDM symbols constituting the PPDU.Furthermore, contiguous subcarriers on the frequency axis may be subcarriers with contiguous subcarrier indices, excluding subcarrier indices assigned to unused subcarriers. Note that, when information identifying each subcarrier, such as a subcarrier index, is not assigned, contiguous subcarriers on the frequency axis may be a set of subcarriers arranged at predetermined intervals from low to high frequencies or from high to low frequencies. Contiguous subcarriers on the frequency axis may be a set of subcarriers arranged from low to high frequencies or from high to low frequencies according to a predetermined rule. In the following description, an RU configured with multiple subcarriers arranged contiguously on the frequency axis may be referred to as a CRU, and an RU configured with multiple subcarriers arranged such that at least some of the subcarriers are discontinuous on the frequency axis may be referred to as a DRU.

[0020] FIG. 4 illustrates the concept of OFDMA using a DRU. In FIG. 4, STA111 to STA113 transmit data to AP101 using OFDMA using a DRU. For example, STA111 to STA113 each transmit using a DRU assigned by AP101. Assume that DRU401 to DRU403 are assigned to STA111 to STA113, respectively. For example, DRU401 may be configured with non-contiguous subcarriers. In DRU401, each of the subcarriers constituting the DRU may be arranged so as to be distributed across the bandwidth of the PPDU. Similarly, the subcarriers constituting DRU402 and DRU403 may be arranged so as to be distributed across the bandwidth of the PPDU. Note that some of the subcarriers constituting each DRU may be contiguous on the frequency axis. By arranging at least some of the subcarriers so as not to be contiguous on the frequency axis, the transmission power density may be reduced. Furthermore, the subcarriers constituting each of the DRUs 401 and 402 are set so as not to overlap on the frequency axis. Similarly, the subcarriers constituting each of the DRUs 401 and 403 do not overlap on the frequency axis, and the subcarriers constituting each of the DRUs 402 and 403 do not overlap on the frequency axis. By assigning each DRU configured in this manner to each STA 110, signals transmitted from each STA 110 are received by the AP 101 without interfering with each other, and the transmit power density of signals transmitted from each STA 110 can be reduced. Note that the signal received by the AP 101 is a combination on the frequency axis of the DRUs 401 to 403 assigned to STA 111 to STA 113. FIG. 4 conceptually illustrates the combined signal 404. Note that the arrangement of the subcarriers constituting each of the DRUs 401 to 403 in FIG. 4 is conceptual for explanation purposes, and the actual arrangement of the subcarriers may vary. The number and arrangement pattern of the subcarriers constituting the DRUs may be regular or irregular. For example, the number and arrangement pattern of subcarriers constituting the DRU may be shared in advance between the AP 101 and each of the STAs 110.When AP 101 performs communication, it notifies each STA 110 of information that can identify the arrangement of subcarriers that make up the DRU to be assigned, so that the STA 110 can identify the arrangement on the frequency axis of the subcarriers that make up the DRU that the STA 110 should use. For example, AP 101 can use a trigger frame to notify STA 110 of information that can identify the arrangement of subcarriers that make up the DRU that the STA 110 should use.

[0021] In this way, when a DRU is used, the transmission power density is reduced by distributing each subcarrier constituting the RU across a wide frequency band, allowing the communication device 100 to transmit with a higher transmission power for each subcarrier than when a CRU is used. However, when the AP and the STA are each capable of implementing an OFDMA communication method using a CRU and an OFDMA communication method using a DRU, communication is not possible if the communication method used by the AP and the STA use different communication methods. For example, if the AP 101 assigns an RU to the STA 111 assuming a DRU, and the STA 111 transmits using subcarriers corresponding to the RU assigned assuming a CRU, the AP 101 will not be able to receive the signal. This occurs because the subcarriers assigned by the AP 101 to the STA 111 are different from the subcarriers used by the STA 111 for transmission. Furthermore, when AP 101 allocates radio resources to STA 111 and STA 112 assuming a DRU, if one of the STAs transmits assuming a CRU, interference may occur in the reception of AP 101. For example, if STA 111 transmits using subcarriers corresponding to the RU assigned assuming a CRU, and STA 112 transmits using subcarriers corresponding to the RU assigned assuming a DRU, interference may occur in some subcarriers. This occurs because, when OFDMA transmission using a CRU and OFDMA transmission using a DRU are performed in parallel in the same frequency band, the same subcarriers may be used even if the RU indexes used in each transmission are different. Thus, even if each communication device is capable of performing OFDMA communication using a CRU and OFDMA communication using a DRU, communication may be impossible due to the difference in the communication methods used by each device.

[0022] In consideration of these circumstances, a communication device in this embodiment, when communicating a data frame using OFDMA with a DRU, first transmits a predetermined frame set with a specific value indicating that communication using OFDMA with a DRU will be performed. Then, after transmitting the predetermined frame, the communication device communicates the data frame using OFDMA with the DRU. For example, the communication device is capable of executing a first communication method using OFDMA in which radio resources are allocated using at least two or more first-type RUs (DRUs). The communication device is also capable of executing a second communication method using OFDMA in which radio resources are allocated using at least two or more second-type RUs (CRUs). The first-type RU may be a DRU configured with multiple subcarriers arranged so that at least some of the subcarriers are discontinuous on the frequency axis. The second-type RU may be a CRU configured with multiple subcarriers arranged so that they are contiguous on the frequency axis. When communicating a data frame with a partner communication device using the first communication method, the communication device transmits to the partner communication device a predetermined frame set with a specific value indicating that the first communication method will be used. This can indicate to the other communication device that the first communication method will be used. Furthermore, when communicating data frames with the other communication device using the second communication method, the communication device transmits a predetermined frame in which no specific value is set to the other communication device. This can indicate to the other communication device that the second communication method will be used. After transmitting the predetermined frame, the communication device communicates data frames with the other communication device using the communication method indicated in the predetermined frame. With this configuration, the communication method to be used for data frame communication is shared between the communication devices before communicating data frames using OFDMA using a DRU or CRU.

[0023] Furthermore, the communication device may transmit a predetermined frame further including identification information capable of identifying an RU allocated to the other communication device. The communication device may communicate data frames with the other communication device using subcarriers identified based on whether a specific value indicating the use of the first communication method is set and the identification information. The other communication device may communicate data frames using subcarriers identified based on the identification information included in the predetermined frame capable of identifying an RU allocated to the device itself and whether a specific value indicating the use of the first communication method is set. With this configuration, subcarriers to be used in communication are uniquely identified based on a combination of the communication method used and information indicating the RU allocation. This enables the use of common RU types and RU indexes when allocating radio resources using a DRU and when allocating radio resources using a CRU. Furthermore, the same region of the frame can be used to notify the RU allocation when allocating radio resources using a DRU and when allocating radio resources using a CRU, thereby reducing the amount of information exchanged. The device configuration, functional configuration, processing examples, etc. of a communication device that performs such operations will be described below.

[0024] (DRU configuration example) First, an example configuration of a DRU will be described. Like a CRU, a DRU is configured with multiple subcarriers. For example, the number of subcarriers constituting each RU of each RU type in a DRU may be the same as the number of subcarriers constituting each RU of each RU type in a CRU. That is, possible RU types in a DRU include 26-tone RU, 52-tone RU, 106-tone RU, 242-tone RU, and 484-tone RU. The number of subcarriers constituting each DRU of each RU type may be 26, 52, 106, 242, or 484, respectively.

[0025] Furthermore, in the case of OFDMA using DRUs, the number of DRUs that can be arranged on the frequency axis to configure a PPDU of a specific bandwidth may be the same as the number of CRUs that can be arranged on the frequency axis to configure a PPDU of the same bandwidth in the case of OFDMA using CRUs. For example, for a PPDU with an 80 MHz bandwidth, for RU types of 26-tone RU, 52-tone RU, and 106-tone RU, 37, 16, and 8 DRUs can be arranged on the frequency axis, respectively. Similarly, for RU types of 242-tone RU and 484-tone RU, 4 and 2 DRUs can be arranged on the frequency axis, respectively. Note that in actual OFDMA, multiple DRUs of different RU types can be arranged on the frequency axis so as not to overlap.

[0026] On the other hand, the arrangement of subcarriers constituting a DRU on the frequency axis may differ from the arrangement of subcarriers constituting a CRU on the frequency axis. First, Figure 5 shows an example of the correspondence between the subcarrier indexes in OFDMA using a CRU shown in Figures 2 and 3 and the subcarrier indexes in OFDMA using a DRU. The subcarrier indexes in OFDMA using a DRU are referred to as DRU subcarrier indexes. For example, assume that the subcarriers assigned carrier indexes in a DRU are data subcarriers and pilot subcarriers. In this case, for each RU type, the number of subcarriers constituting a PPDU can be 26 x 37 = 962, 52 x 16 = 832, 106 x 8 = 848, 242 x 4 = 968, and 484 x 2 = 968, respectively. Figure 5 shows an example for a 106-tone RU corresponding to a PPDU with an 80-MHz bandwidth. The DRU subcarrier indexes shown in FIG. 5 are integers starting from 1 and assigned in increments of 1 from lower frequencies to higher frequencies. In this case, in OFDMA using a DRU, any value in the range of 1 to 848 may be assigned as the DRU subcarrier index to each subcarrier. As an example, in OFDMA using a CRU, DRU subcarrier indices of 1 to 106 may be assigned to subcarriers assigned with subcarrier indices of -499 to -394, respectively. Furthermore, in OFDMA using a CRU, DRU subcarrier indices of 107 to 212 may be assigned to subcarriers assigned with subcarrier indices of -365 to -260, respectively. Note that in OFDMA using a CRU, subcarrier indices are also assigned to unused subcarriers, and the subcarrier indices are discontinuous between RUs. On the other hand, if DRU subcarrier indexes are assigned only to subcarriers that transmit data or pilot signals as described above, the DRU subcarrier indexes will be continuous on the frequency axis. Note that the correspondence between the DRU subcarrier indexes and the CRU subcarrier indexes is not limited to the example in Figure 5. For example, in the DRU subcarrier indexes, indexes may be assigned to unused subcarriers.Note that while Figure 5 shows an example for a 106-tone RU, integer DRU subcarrier indices starting from 1 can be assigned to each subcarrier in the same way for 26-tone RUs, 52-tone RUs, 242-tone RUs, and 484-tone RUs. For example, for each RU type, integers in the ranges 1 to 962, 1 to 832, 1 to 968, and 1 to 968 can be assigned consecutively in order from the lowest frequency subcarrier. Furthermore, for bandwidths of 20 MHz, 40 MHz, 160 MHz, and 320 MHz, DRU subcarrier indices can be assigned in the same way for each RU type corresponding to each bandwidth.

[0027] The subcarriers constituting the DRU will now be described. First, an RU index may be assigned to each DRU. As with OFDMA using a CRU, the RU index may be assigned a value within a range depending on the bandwidth and RU type. For example, for 26-tone RUs, 52-tone RUs, and 106-tone RUs corresponding to PPDUs with an 800 MHz bandwidth, values ​​in the ranges of 1 to 37, 1 to 16, and 1 to 8 may be assigned to each DRU as the RU index, respectively. Similarly, for 242-tone RUs and 484-tone RUs, values ​​in the ranges of 1 to 4 and 1 to 2 may be assigned to each DRU as the RU index, respectively. Then, based on the DRU subcarrier index and RU index, each DRU may be configured with subcarriers that satisfy the following (Equation 1):

[0028] DRU subcarrier index mod number of RUs = RU index - 1 (Equation 1) Here, mod is a modulo operator. The number of RUs is the number of RUs on the frequency axis that make up one PPDU. For example, for 26-tone RUs, 52-tone RUs, 106-tone RUs, 242-tone RUs, and 484-tone RUs, the number of RUs can be 37, 16, 8, 4, and 2, respectively.

[0029] Figure 6 shows the relationship between the RU index and the DRU subcarrier index of the subcarrier that constitutes the DRU indicated by that RU index. Figure 6 also shows the relationship between the RU index and the DRU subcarrier index for each RU type corresponding to a PPDU with an 80 MHz bandwidth. In Figure 6, "x" is the DRU subcarrier index. For example, if "x" satisfies the equation associated with each RU index, it may be the DRU subcarrier that constitutes that RU index. For example, in the case of a 26-tone RU, a subcarrier with a DRU subcarrier index of 1 may constitute RU2 because 1 mod 37 = 1. Also, in the case of a 106-tone RU, a subcarrier with a DRU subcarrier index of 100 may constitute RU5 because 100 mod 8 = 4. While Fig. 6 shows an example of a PPDU with a bandwidth of 80 MHz, the frequency allocation of the subcarriers that make up each DRU can be determined using Equation 1 in the same way for PPDUs with bandwidths of 20 MHz, 40 MHz, 160 MHz, and 320 MHz. Note that the method of determining the subcarriers that make up a DRU is not limited to Equation 1. For example, the subcarrier indexes that make up each DRU may be determined using random numbers. Each DRU may be configured so that the subcarriers that make up one DRU are distributed across the bandwidth.

[0030] In the above example, the subcarriers constituting each DRU are distributed across the entire bandwidth occupied by the PPDU. That is, in the above example, the range over which the subcarriers constituting each DRU are distributed on the frequency axis may be equal to the bandwidth of the PPDU. Alternatively, the subcarriers constituting the DRU may be distributed within a predetermined bandwidth rather than across the entire bandwidth of the PPDU. For example, if the bandwidth of the PPDU exceeds a predetermined threshold, the subcarriers constituting the DRU may be distributed across the predetermined bandwidth. In this case, one PPDU is divided into predetermined bandwidths on the frequency axis, and DRUs may be allocated and assigned using a DRU allocation pattern corresponding to each predetermined bandwidth. Here, allocating DRUs using a DRU allocation pattern corresponding to each predetermined bandwidth may involve, for example, allocating DRUs using the number of RUs, DRU index, DRU subcarrier index, etc. of each DRU type corresponding to the predetermined bandwidth. For example, if the PPDU bandwidth is 160 MHz and the predetermined threshold is 80 MHz, the PPDU may be divided on the frequency axis into two 80 MHz bandwidth regions, and DRUs may be allocated for each region using a DRU allocation pattern corresponding to the 80 MHz bandwidth. Similarly, if the PPDU bandwidth is 320 MHz, the PPDU may be divided on the frequency axis into four 80 MHz bandwidth regions, and DRUs may be allocated for each region using a DRU allocation pattern corresponding to the 80 MHz bandwidth. In this way, the DRU allocation for one PPDU may be configured by repeating or stacking DRU allocation patterns corresponding to a predetermined bandwidth on the frequency axis. Note that in each band or region, DRUs may be allocated using various combinations of different RU types included in the DRU allocation pattern, and the DRU allocation may differ for each band. Furthermore, as a modified example described below, RUs may be allocated using either CRUs or DRUs for each band in one PPDU. In any case, the subcarriers that make up the DRU are more dispersed than those of the CRU's Middle-26 Tone RU19. Therefore, using a DRU makes it possible to distribute the average power transmitted by a single STA to its surroundings on the frequency axis.

[0031] FIG. 7 shows an example of DRU allocation in a 160 MHz bandwidth PPDU using two DRU allocation patterns corresponding to an 80 MHz bandwidth PPDU. The horizontal axis in FIG. 7 represents frequency, with one 80 MHz band formed from the center frequency of the 160 MHz bandwidth PPDU toward lower frequencies and another 80 MHz band formed toward higher frequencies. In this case, DRUs are allocated in the lower 80 MHz frequency band using a DRU allocation pattern corresponding to the 80 MHz bandwidth PPDU. Similarly, DRUs are allocated in the higher 80 MHz frequency band using a DRU allocation pattern corresponding to the 80 MHz bandwidth PPDU. For example, the DRU allocation using RU types from 26-tone RU to 484-tone RU in FIG. 6 can be applied to both the lower 80 MHz band and the upper 80 MHz band of the 160 MHz frequency band. In this case, the bandwidth in which the subcarriers constituting one DRU are allocated can be 80 MHz.

[0032] When a single PPDU is divided into multiple bandwidths and DRUs are allocated using DRU allocation patterns corresponding to each bandwidth, RU indices may be assigned so that they are unique to the PPDU bandwidth. For example, when a 160-MHz PPDU is divided into two 80-MHz bandwidths on the frequency axis and DRUs are allocated using 26-tone RUs in each band, RU indices RU1 to RU37 may be assigned to each band. In this case, the RU indices for the lower frequency band may be RU1 to RU37, and the RU indices for the higher frequency band may be RU38 to RU74. This eliminates the need to notify the STA 110 whether the lower frequency band or the higher frequency band is allocated when allocating a DRU to the STA 110 in PPDU communication. Furthermore, an index indicating the position of that band on the frequency axis may be assigned to each bandwidth that is the unit of DRU allocation pattern repetition (unit into which the PPDU is divided). For example, the PPDU band may be divided by bandwidths that are the units of repetition (units into which the PPDU is divided), and indexes may be assigned in ascending order of frequency. Such indexes may be called band indexes. For example, when repetition is performed (the PPDU is divided) in units of 80 MHz bandwidth, they may be called 80 MHz band indexes. In this case, the DRU assigned to the STA 110 may be uniquely identified by a combination of the band index, RU type, and RU index. FIG. 7 shows an example in which an index value of 1 is assigned to the lower frequency and an index value of 2 is assigned to the higher frequency. In this case, the same RU index may be used in assigning RUs to each band. Note that the index values ​​assigned to each band may be other than these. For example, an index value of 0 may be assigned to the lower frequency and an index value of 1 may be assigned to the higher frequency. Alternatively, an index value of 1 may be assigned to the lower frequency and an index value of 0 may be assigned to the higher frequency.

[0033] Although the above description assumes that the number of subcarriers constituting the DRU and the number of subcarriers constituting the CRU are the same, the number of subcarriers constituting the DRU may be different from the number of subcarriers constituting the CRU. Furthermore, the number of RUs included in a PPDU in OFDMA using a DRU may be different from the number of RUs included in a PPDU in OFDMA using a CRU. Furthermore, the arrangement of the subcarriers constituting the DRU on the frequency axis may be different from that described above. For example, the CRU may be composed of multiple subcarriers arranged contiguously on the frequency axis, and the DRU may be composed of multiple subcarriers arranged so that at least some of the subcarriers are discontinuous on the frequency axis, and each may be used in OFDMA. Furthermore, when a PPDU is divided into multiple bands and RUs are assigned to each band, assignment using the CRU may be performed in some bands and assignment using the DRU in other bands. By using the CRU and DRU for assignment independently in each band, interference between the CRU and DRU may be eliminated.

[0034] (Example of OFDMA communication using DRU) An example of communication using OFDMA with a DRU will be described. FIG. 8 shows an example of a sequence between communication devices when OFDMA with a DRU is applied to uplink data communication from a STA to an AP. In this example, an example will be described in which, when an AP 101 is connected to STAs 111 to 113, each of the STAs 111 to 113 transmits data in parallel using OFDMA. This type of communication may be called Uplink Multi-user OFDMA (UL MU OFDMA). First, the AP 101 determines whether or not to cause the STAs 111 to 113 to transmit. For example, based on whether or not each STA 110 has data to transmit, the AP 101 may determine to cause transmission if data is available, or not to cause transmission if data is not available. For example, the AP 101 may transmit a Buffer Status Report Polling (BSRP) to identify whether or not each STA 110 has data stored therein and the amount of data (F801). Upon receiving the BSRP, the STA 110 may report the amount of data stored therein to the AP 101. For example, each STA 110 may report by transmitting a Buffer Status Report (BSR) (F802). Note that the AP 101 may obtain the amount of data accumulated by each STA 110 using other methods, or may use other methods to determine whether or not to cause each STA 110 to transmit. For example, the STA 110 may notify the AP 101 of the amount of data accumulated by itself by periodically transmitting a BSR without receiving a BSRP from the AP 101. The AP 101 may also estimate the amount of data accumulated by each STA 110 based on the history of past communications with that STA 110.

[0035] The AP 101 may determine the amount of resources to allocate to each identified STA 110 based on whether or not each identified STA 110 has accumulated data and the amount of data. For example, the AP 101 may determine the amount of resources to allocate to each STA 110 so that the ratio of the amount of data accumulated by each STA 110 to the ratio of the number of subcarriers allocated to each STA 110 is proportional. The AP 101 may then allocate RUs to each STA 110 based on the amount of resources determined to be allocated to each STA 110. For example, the AP 101 may allocate RUs to STAs 110 that have accumulated a large amount of data using an RU type that comprises a large number of subcarriers. The AP 101 may also allocate multiple RUs to STAs 110 that have accumulated a large amount of data.

[0036] The AP 101 may use only the DRU to perform allocation to each STA, or may use the DRU to perform allocation to some STAs 110 and the CRU to perform allocation to other STAs 110. Note that if the DRU should not be used, the AP 101 may use only the CRU to perform allocation to each STA. The following describes an example in which the AP 101 uses only the DRU or only the CRU to perform allocation to each STA 110. Note that a case in which the AP 101 uses the DRU to perform allocation to some STAs 110 and the CRU to perform allocation to other STAs 110 will be described in a modified example described later. The AP 101 may select whether to use the DRU or the CRU based on the capability information of each STA 110. For example, the AP 101 may use the DRU to perform allocation to STAs 110 that can perform OFDMA communication using the DRU. The AP 101 may use the CRU to perform allocation to STAs 110 that cannot perform OFDMA communication using the DRU. This makes it possible to select an appropriate allocation method depending on the capabilities of the STA 110. The capability information may include information indicating that communication using OFDMA with a DRU is possible or information indicating that communication using OFDMA with a CRU is possible. The AP 101 may exchange capability information of each communication device when each STA 110 performs a connection process with the AP 101. For example, the AP 101 may notify the STA 110 of its capability information using a Beacon frame, a Probe Response frame, an Association Response frame, etc. For example, the STA 110 may notify the AP 101 of its capability information using a Probe Request frame, an Association Request frame, etc. The AP 101 may determine to perform allocation using the DRU if all of the STAs 110 participating in the transmission of one PPDU transmitted using UL MU OFDMA are capable of communication using OFDMA with a DRU. Furthermore, the AP 101 may determine to perform allocation using the CRU if any of the STAs 110 participating in the transmission of one PPDU transmitted using UL MU OFDMA is not capable of communication using OFDMA using the DRU.Furthermore, AP 101 may determine to perform allocation using the CRU if the percentage of STAs 110 connected to the AP and capable of performing OFDMA communication using the DRU is smaller than the percentage of STAs 110 that cannot perform OFDMA communication using the DRU. AP 101 may also determine to perform allocation using the CRU if the percentage of STAs 110 connected to the AP and capable of performing OFDMA communication using the DRU is lower than a predetermined threshold.

[0037] The method by which the AP 101 selects whether to use the CRU or the DRU for OFDMA communications is not limited to the above. For example, the AP 101 may select whether to use the DRU or the CRU based on the geographical distance between the AP 101 and each STA 110 and the amount of radio wave attenuation. For example, the AP 101 may use the DRU when, among the STAs 110 participating in the transmission of a single PPDU transmitted via UL MU OFDMA, the number of STAs 110 far from the AP 101 is greater than the number of STAs 110 close to the AP 101. Furthermore, the AP 101 may use the CRU when, among the STAs 110 participating in the transmission of a single PPDU transmitted via UL MU OFDMA, the number of STAs 110 far from the AP 101 is less than the number of STAs 110 close to the AP 101. This allows transmissions to be performed using higher transmission power when there are many STAs 110 with high radio wave attenuation, thereby improving communication quality. Furthermore, when there are many STAs 110 with low radio wave attenuation, transmissions are performed using lower transmission power, thereby reducing interference with other networks. For example, the AP 101 may perform allocation using the DRU if the number of STAs 110 far from the AP 101 among the STAs 110 participating in the transmission of one PPDU transmitted by UL MU OFDMA is equal to or greater than a predetermined threshold. The AP 101 may determine whether each STA 110 is near or far from the AP 101 based on the received power from each STA 110. For example, if the RSSI of a signal received from each STA 110 is below a predetermined threshold, the AP 101 may determine that the STA 110 has significant radio wave attenuation and is far from the AP 101. RSSI may be an abbreviation for Received Signal Strength Indicator. The AP 101 may determine whether each STA 110 is near or far from the AP 101 by acquiring the received power at the STA 110. The AP 101 may also determine whether each STA 110 is far from the AP 101 by acquiring location information of the AP 101 and location information of the STA 110.

[0038] The AP 101 notifies each STA 110 of information (RU allocation information) that can identify the RU allocated to that STA 110. For example, the AP 101 may transmit a Trigger frame including the RU allocation information to each STA 110 (F803). By using the Trigger frame, the AP 101 may notify each STA 110 of the RU allocation information and instruct each STA 110 to transmit data. For example, the AP 101 may notify the STA 110 of whether the allocation uses a CRU or a DRU, the RU type, the RU index, and the like, as the RU allocation information. For example, the AP 101 may indicate to the STA 110 that communication will be performed using OFDMA with a DRU by setting a value indicating that the allocation is performed using a DRU in a predetermined field of the Trigger frame. Furthermore, the AP 101 may indicate to the STA 110 that communication will be performed using OFDMA with a CRU by not setting a value indicating that the allocation is performed using a DRU in a predetermined field of the Trigger frame. The STAs 111 to 113 may transmit data based on the RU allocation information included in the received Trigger frame (F804). For example, when the STA 110 receives the RU allocation information assigned to it, indicating whether the RU is a CRU or a DRU, and the RU type and RU index of the RU, the STA 110 may identify the subcarriers to be used for transmission based on a correspondence table such as that shown in FIG. 3 or 6. When the AP 101 receives data from each STA 110 via each subcarrier, the AP 101 acknowledges the data (F805). For example, the AP 101 may acknowledge the data collectively to the STAs 111 to 113 by transmitting a Multi-STA Block Ack. Note that the PPDU transmitted from each STA 110 based on the Trigger frame may be referred to as a Trigger-based PPDU (TB-PPDU). In the TB-PPDU, the frames transmitted by each STA 110 may be combined on the frequency axis in the AP 101 to form a single PPDU. In this embodiment, the PPDU and the TB-PPDU are sometimes referred to as PPDU without distinction. In this embodiment, it is assumed that the TB-PPDU transmitted from each STA 110 using the DRU is a UHR TB PPDU.However, this is not limited to this.

[0039] (Trigger frame configuration example) An example of the configuration of a Trigger frame transmitted by the AP 101 to the STA 110 will be described. As described above, the AP 101 can use the Trigger frame to notify each STA 110 of allocation information of RUs allocated to it. For example, the Trigger frame is a Basic Trigger Frame. These Trigger frames are MAC (Medium Access Control) frames transmitted using a PPDU such as a UHR PPDU or an EHT PPDU. FIG. 9 shows an example of the configuration of a Trigger frame. The Trigger frame includes a Frame Control field 901, a Duration field 902, an RA field 903, and a TA field 904. The Trigger frame also includes a Common Info field 905, a User Info List field 906, a Padding field 907, and an FCS field 908. The Frame control field 901 indicates the type of the frame. The Frame control field 901 includes a Type subfield and a Subtype subfield. For example, setting the value of "01" in the Type subfield can indicate that this frame is a Control frame. Furthermore, by setting the value of "0010" in the Subtype subfield, it can be indicated that this frame is a Trigger frame. The estimated time required for exchanging data and an acknowledgment can be set in the Duration field 902. The MAC address of the communication device that is the destination of this frame can be set in the RA field 903. In the case of a Basic Trigger Frame, a broadcast address can be set in the RA field 903. RA stands for Receiver Address. The TA field 904 can store the MAC address of the communication device that is the sender of this frame. In the case of a Basic Trigger Frame, the MAC address and BSSID of AP 101 can be set in the TA field 904. TA stands for Transmitter Address.The Common Info field 905 contains information commonly used by each STA 110 that receives this frame. The User Info List field 906 contains one or more User Info fields 909. Each User Info field 909 can be used to notify each STA 110 that should receive this frame of information. For example, the User Info field 909 can contain information identifying the communication device with which the TXOP established by this frame is shared, information indicating the duration of the TXOP, information for identifying the bandwidth to be used, etc. The User Info List field 906 can also contain one Special User Info field. The Special User Info field can contain shared information not included in the Common Info field. The Special User Info field can be omitted if there is no corresponding shared information. The Padding field 907 can contain padding data. The FCS field 908 can contain information used by the STA 110 to check whether the frame was received correctly.

[0040] The AP 101 may notify the STA 110 of an RU allocation using the User Info field 909. The User Info field 909 may include an AID12 subfield 911, an RU Allocation subfield 912, a UL FEC Coding Type subfield 913, and a UL EHT-MCS subfield 914. The User Info field 909 may also include a Reserved subfield 915, an SS Allocation subfield 916, and a UL Target Receive Power subfield 917. The User Info field 909 may also include a PS160 subfield 918, a DRU subfield 919, and a Trigger Dependent User Info subfield 920. The AID12 subfield 911 is set with information that identifies the STA 110 that is the target of this User Info field 909. For example, the AID assigned to the target STA 110 may be set. The AID is an identifier assigned to the STA 110 when the AP 101 and the STA 110 establish a connection, and the AID is assigned so that the STA 110 can be uniquely identified. AID is an abbreviation for Association Identifier. The STA 110 can recognize from this subfield that the User Info field 909 contains information intended for the STA 110. The RU Allocation subfield 912 indicates the RU allocated to the STA 110 that is the target of the User Info field 909. For example, the RU Allocation subfield 912 can include information indicating an RU type and an RU index. For example, the RU Allocation subfield 912 can indicate a combination of an RU type and an RU index in decimal or binary notation. The UL FEC Coding Type subfield 913 indicates the type of coding used for data communication. The UL EHT-MCS subfield 914 indicates the MCS used for data communication. MCS is an abbreviation for Modulation and Coding Scheme. The Reserved subfield 915 is a reserved area.The SS Allocation subfield 916 indicates the number of spatial streams to be used by the STA 110 targeted by this User Info field 909, etc. The UL Target Receive Power subfield 917 indicates the expected received power at the antenna of the AP 101. The PS 160 subfield 918 can be used to indicate the band of the allocated RU. For example, the PS 160 subfield 918 can indicate the band allocated to the STA 110 when used in conjunction with the RU Allocation subfield 912. The Trigger Dependent User Info subfield 920 is an optional field that is provided depending on the type of Trigger frame.

[0041] The DRU subfield 919 indicates whether or not a DRU will be used in the OFDMA communication following this Trigger frame. For example, the AP 101 may indicate that it will perform OFDMA communication using a DRU by setting the value of this subfield to a specific value. Alternatively, the AP 101 may indicate that it will perform OFDMA communication using a CRU by not setting the value of this subfield to a specific value. The AP 101 may also indicate that it will perform communication using another communication method by not setting the value of this subfield to a specific value. For example, the AP 101 may set the value of this subfield to 1 when performing OFDMA communication using a DRU. Alternatively, the AP 101 may set the value of this subfield to 0 when performing OFDMA communication using a CRU. Alternatively, the AP 101 may set the value of this subfield to 0 when performing communication using another communication method. The other communication method may be, for example, single-user communication. The AP 101 may use a 2-bit field to set a value of 2 when performing OFDMA communication using a DRU, a value of 1 when performing OFDMA communication using a CRU, and a value of 0 when performing communication using another communication method. The STA 110 may identify the subcarriers allocated to the STA 110 based on the RU Allocation subfield 912, the UL BW subfield included in the Common Info field 905, and the DRU subfield 919. For example, if the UL BW subfield indicates the bandwidth of the PPDU and the RU Allocation subfield 912 indicates an RU type and an RU index, the STA 110 can identify the RU allocated to the STA 110 based on these. For example, the STA 110 may identify the RU allocated to the STA 110 according to a correspondence table such as that shown in FIG. 3 or FIG. 6. Then, for example, if the DRU subfield 919 indicates that allocation is using a DRU, the STA 110 can identify the subcarriers to use by identifying the DRU subcarrier index corresponding to the allocated RU.If the DRU subfield 919 indicates that the allocation is using a CRU, the STA 110 can identify the subcarrier to use by identifying the subcarrier index corresponding to the allocated RU.

[0042] The field used by the AP 101 to allocate RUs to the STA 110 is not limited to the User Info field 909. For example, the AP 101 may notify the STA 110 of information regarding RU allocation using a combination of the Common Info field 905 and the User Info field 909 shown in FIG. 9. For example, the AP 101 may use the Common Info field 905 to notify the STA 110 of whether to use a DRU or a CRU for OFDMA communication, and may use the User Info field 909 to notify the STA 110 of RU allocation information. FIG. 10 shows an example of the configuration of the Common Info field 905. The Common Info field 905 includes a Trigger Type subfield 1001, a UL Length subfield 1002, a More TF subfield 1003, and a CS Required subfield 1004. The Common Info field 905 includes a UL BW subfield 1005 and a GI And HE / EHT / UHR-LTF Type / Triggered TXOP Sharing Mode subfield 1006. The Common Info field 905 includes a Number Of HE / EHT / UHR-LTF Symbols subfield 1008 and an LDPC Extra Symbol Segment subfield 1010. The Common Info field 905 includes an Ap Tx Power subfield 1011, a Pre-FEC Padding Factor subfield 1012, and a PE Disambiguity subfield 1013. The Common Info field 905 includes a UL Spatial Reuse subfield 1014, an HE / EHT / UHR P160 subfield 1016, and a Special User Info Field Flag subfield 1017. The Common Info field 905 includes a Trigger Dependent Common Info subfield 1019 and Reserved subfields 1007, 1009, 1015, and 1018.

[0043] The Trigger Type subfield 1001 indicates the type of the Trigger frame. For example, if the value of the Trigger Type subfield 1001 is set to 0, it indicates a Basic Trigger frame. Table 1 shows an example of the correspondence between the value of the Trigger Type subfield 1001 and the type of the Trigger frame. The UL Length subfield 1002 indicates the value of the L-SIG LENGTH field of the subsequent PPDU (TB-PPDU). The More TF subfield 1003 indicates whether or not a subsequent Trigger frame exists. The CS Required subfield 1004 indicates whether or not carrier sensing is required for the STA 110 that is the target of the Trigger frame. The UL BW subfield 1005 indicates the bandwidth of the signal field of the subsequent PPDU (TB-PPDU). The GI And HE / EHT / UHR-LTF Type / Triggered TXOP Sharing Mode subfield 1006 indicates the GI and LTF type of the subsequent PPDU (TB-PPDU). The Number Of HE / EHT / UHR-LTF Symbols subfield 1008 indicates the number of LTF symbols in the following PPDU (TB-PPDU). The LDPC Extra Symbol Segment subfield 1010 indicates whether or not an LDPC Extra Symbol Segment is included in the following PPDU (TB-PPDU). The Ap Tx Power subfield 1011 indicates the total transmit power from each AP antenna. The Pre-FEC Padding Factor subfield 1012 indicates the Pre-FEC Padding Factor. The PE Disambiguity subfield 1013 indicates PE disambiguity. The UL Spatial Reuse subfield 1014 indicates the value to be stored in the Spatial Reuse field of the signal field of the following PPDU (TB-PPDU).The HE / EHT / UHR P160 subfield 1016 indicates whether the primary 160 MHz of the following PPDU (TB-PPDU) is an EHT TB PPDU, an HE TB PPDU, or a UHR TB PPDU. The Special User Info Field Flag subfield 1017 indicates extended common information that is not specific to a user. The Trigger Dependent Common Info subfield 1019 indicates common information that depends on the type of Trigger frame. The Reserved subfields 1007, 1009, 1015, and 1018 are reserved areas.

[0044] The AP 101 may use the Trigger Type subfield 1001 to notify the STA 110 that it will perform communication using OFDMA with DRU. Table 1 shows the correspondence between values ​​set in the Trigger Type subfield 1001 and the types of Trigger frames corresponding to each value. For example, the AP 101 may indicate that this Trigger frame is a DRU-variant Trigger frame by setting a value of 9 in the Trigger Type subfield. In this case, the STA 110 may recognize that subsequent data communication will be performed using OFDMA with DRU by receiving this frame. Note that if the Trigger frame is a DRU-variant Trigger frame, the subfields following the Trigger Type subfield 1001 may differ from those shown in FIG. 10. In this case, the AP 101 may notify each STA 110 of the RU type and RU index allocated to it using the RU Allocation subfield 912 of the User Info field 909, as described above. The STA 110 may identify the subcarriers allocated to itself based on the RU Allocation subfield 912, the UL BW subfield of the Common Info field 905, and the Trigger Type subfield 1001. Note that the AP 101 may set the value of the Trigger Type subfield 1001 to another value when performing communication using OFDMA with a CRU. Also, the AP 101 may set the value of the Trigger Type subfield 1001 to another value when performing communication using another communication method. Table 1 The AP 101 may provide a new field in the Common Info field 905 to indicate that it will perform OFDMA communication using a DRU. For example, as shown in FIG. 11 , the AP 101 may provide a DRU subfield 1101 between the Special User Info Field Flag subfield 1017 and the Reserved subfield 1018. The AP 101 may indicate that it will perform OFDMA communication using a DRU by setting the DRU subfield 1101 to a specific value. For example, the AP 101 may set the specific value to 1. In this case, the Trigger Type subfield 1001 may be set to a value of 9 or another value. As an example, the AP 101 may indicate that the DRU subfield 1101 in this frame specifies whether to use a DRU or a CRU by setting the Trigger Type subfield 1001 to a value of 9. Also, as an example, when the AP 101 specifies whether to use a DRU or a CRU using the DRU subfield 1101, the Trigger Type subfield 1001 may be used for other purposes. For example, the AP 101 may set a value of 0 in the Trigger Type subfield 1001 to indicate a Basic Trigger frame. The AP 101 may provide the DRU subfield 1101 between multiple other subfields, or may use one of the Reserved subfields to indicate that OFDMA communication using a DRU is to be performed. The AP 101 may also use one of the subfields included in the Common Info field 905 to indicate that OFDMA communication using a DRU is to be performed. The AP 101 may notify each STA 110 of the assigned RU type and RU index using the RU Allocation subfield 912 of the User Info field 909, as described above.The STA 110 may identify the subcarriers allocated to itself based on the RU Allocation subfield 912, the UL BW subfield included in the Common Info field 905, and the DRU subfield 1101. Note that the AP 101 may set the value of the DRU subfield 1101 to another value when performing communication using OFDMA with a CRU. Also, the AP 101 may set the value of the DRU subfield 1101 to another value when performing communication using another communication method.

[0045] (Device configuration example) 12 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 includes, for example, a storage unit 1201, a control unit 1202, a function unit 1203, an input unit 1204, an output unit 1205, a communication unit 1206, and an antenna 1207. The communication device 100 may include multiple antennas.

[0046] The storage unit 1201 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 1201 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.

[0047] The control unit 1202 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 1201. The control unit 1202 may control the entire communication device 100 in cooperation with the control program stored in the storage unit 1201 and an OS (Operating System). The CPU and MPU are abbreviations for Central Processing Unit and Micro Processing Unit, respectively. When the control unit 1202 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.

[0048] Furthermore, the control unit 1202 controls the functional unit 1203 to execute predetermined processes such as communication, image capture, printing, and projection. The functional unit 1203 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 1203 is an image capture unit that performs image capture processing. For example, if the device is a printer, the functional unit 1203 is a print unit that performs print processing. For example, if the device is a projector, the functional unit 1203 is a projection unit that performs projection processing.

[0049] The input unit 1204 receives various operations from the user. The output unit 1205 outputs various types of information to the user via a monitor screen or a speaker. The output from the output unit 1205 may be a display on a monitor screen, an audio output from a speaker, a vibration output, or the like. The input unit 1204 and the output unit 1205 may both be implemented as a single module, such as a touch panel. The input unit 1204 and the output unit 1205 may be integrated with the communication device 100 or may be separate devices.

[0050] The communication unit 1206 controls wireless communication compliant with the IEEE 802.11bn standard. The communication unit 1206 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 1206 controls the antenna 1207 to transmit and receive signals for wireless communication generated by the control unit 1202. The communication unit 1206 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 1206 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 corresponding to each communication standard. The communication device 100 communicates data with a partner communication device via the communication unit 1206. The antenna 1207 may be configured as a separate unit from the communication unit 1206, or may be configured together with the communication unit 1206 as a single module.

[0051] Antenna 1207 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. 12 shows a configuration in which communication device 100 has two antennas 1207, 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 1206 for each antenna.

[0052] (Example of functional configuration) The functional configuration of the communication device 100 (AP 101 and STA 110) in this embodiment will be described. FIG. 13 shows an example of a block diagram of the communication device 100. These functions can be realized, for example, by the control unit 1202 executing a program stored in the storage unit 1201, or by a processing function unit in the communication unit 1206. Note that FIG. 13 is a diagram 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 FIG. 13 can be integrated into a single functional block, or one functional block can be divided into multiple functional blocks. FIG. 13 shows an example configuration of the communication device 100. The communication device 100 can be configured to include a wireless LAN control unit 1301, a wireless frame generation unit 1302, a wireless frame processing unit 1303, a UI control unit 1304, and a memory control unit 1305. The wireless LAN control unit 1301 includes an antenna and circuitry for transmitting and receiving frames to and from a remote communication device, and a program for controlling them. The wireless LAN control unit 1301 controls wireless LAN communication using frames generated by the wireless frame generation unit 1302 in accordance with the IEEE 802.11 standard series. For example, the wireless LAN control unit 1301 communicates data frames with a remote communication device using an OFDMA communication method using a DRU or an OFDMA communication method using a CRU. For example, when communicating using OFDMA with a DRU, the wireless LAN control unit 1301 of the AP 101 can receive data transmitted using each subcarrier constituting the DRU assigned to each STA 110. Furthermore, the wireless LAN control unit 1301 of the STA 110 can perform communication based on the communication method to be used and information on the RU assigned to the STA 110, as notified by the wireless frame processing unit 1303. For example, when performing OFDMA communication using a DRU, the wireless LAN control unit 1301 of the STA 110 can transmit data using each subcarrier constituting the DRU assigned to the STA 110. The wireless frame generation unit 1302 generates a frame to be transmitted by the wireless LAN control unit 1301.For example, the wireless frame generation unit 1302 of the AP 101 generates a Trigger frame including the communication method to be used with the STAs 110 and allocation information of the RUs allocated to each STA 110. For example, the wireless frame generation unit 1302 of the STA 110 generates a data frame to be transmitted using the RUs allocated by the AP 101. The wireless frame processing unit 1303 performs reception processing of frames received by the wireless LAN control unit 1301. For example, the wireless frame processing unit 1303 of the AP 101 executes reception processing of data frames transmitted by each STA 110. For example, the wireless frame processing unit 1303 of the STA 110 performs reception processing of a Trigger frame transmitted by the AP 101 and identifies the communication method to be used for communicating the data frame and the RUs allocated to the STA 110. The wireless frame processing unit 1303 of the STA 110 can notify the wireless LAN control unit 1301 of the identified communication method and RU information. The UI control unit 1304 is configured to include hardware related to a user interface, such as a touch panel or buttons, for accepting operations by a user using the communication device 100, and programs for controlling these hardware. The UI control unit 1304 may have a function for presenting information to the user, such as displaying images or outputting audio, etc. The memory control unit 1305 controls writing and reading of data to and from the memory unit 1206, such as a ROM or RAM, that stores programs and data operated by the communication device 100.

[0053] (AP101 processing flow example) The processing flow of the AP 101 when performing communication using OFDMA with a DRU will be described. FIG. 14 shows an example of a processing flow when the AP 101 performs communication using UL MU OFDMA with the STA 110. This operation flow can be executed by the control unit 1202 of the AP 101 reading and executing a computer program stored in the storage unit 1201. First, the AP 101 collects the data accumulation status of each STA 110 (S1401). For example, the AP 101 can collect the data accumulation status of each STA 110 by transmitting a BSRP addressed to each STA 110 and receiving a BSR in response thereto from each STA 110. The AP 101 determines whether to perform communication using UL MU OFDMA based on the collected data accumulation status (S1402). For example, when data is accumulated in multiple STAs 110, the AP 101 can determine to perform communication using UL MU OFDMA. In cases where no data is accumulated in any of the STAs 110 or where data is accumulated in one STA 110, the AP 101 may determine not to perform communication using UL MU OFDMA. When the AP 101 determines to perform communication using UL MU OFDMA (YES in S1402), it determines the communication method to use and allocates RUs to each STA. For example, the AP 101 determines whether to perform communication using OFDMA using a DRU or a CRU, and allocates RUs to each STA 110 (S1403). For example, the AP 101 may determine whether to perform communication using OFDMA using a DRU or a CRU based on information such as the capability information and radio wave attenuation of each of the STAs 110 participating in UL MU OFDMA. Note that, as will be described later, the AP 101 may determine for each STA 110 whether to perform communication using OFDMA using a DRU or a CRU. In this case, the AP 101 can determine the band to which the RU of each STA 110 is allocated depending on whether the AP 101 uses a DRU or a CRU between the AP 101 and that STA 110.The AP 101 may also determine the RU type and number of RUs to allocate to each STA 110 based on the amount of data stored in that STA 110. The AP 101 may determine the RU index to allocate to each STA 110 based on whether DRU or CRU is to be used with each STA 110 and the determined RU type and number of RUs. The AP 101 transmits a Trigger frame including the communication method to be used in UL MU OFDMA and allocation information of the RUs allocated to each STA 110 (S1404). The AP 101 then sets communication parameters to receive PPDUs transmitted from each STA 110 in response to the Trigger frame (S1405). For example, when communicating using OFDMA using a DRU, the AP 101 sets communication parameters to receive frames from each STA 110 based on the association between RU indexes and DRU subcarrier indexes as shown in FIG. 6. Furthermore, when performing OFDMA communication using a CRU, the AP 101 sets communication parameters to receive frames from each STA 110 based on the correspondence between RU indexes and subcarrier indexes as shown in FIG. 3. When the AP 101 receives a frame from each STA 110, it executes reception processing (S1406). If the reception processing is executed successfully, the AP 101 transmits an acknowledgement to the STA 110 indicating that reception was successful. If the reception processing is not executed successfully, the AP 101 may transmit an acknowledgement to the STA 110 indicating that reception was not successful. The AP 101 may transmit acknowledgements collectively to multiple STAs 110 by transmitting a Multi-STA Block Ack frame.

[0054] On the other hand, when the AP 101 determines not to perform UL MU OFDMA (NO in S1402), it determines whether to suspend operation (S1408). For example, when only one STA 110 stores data, the AP 101 may perform communication by single-user communication (NO in S1408). Note that even when multiple STAs 110 store data, the AP 101 may perform communication in turn by single-user communication. The AP 101 may also perform downlink communication. When performing communication with the STA 110 in this manner, the AP 101 does not suspend operation (NO in S1408) and performs communication processing (S1409). On the other hand, when the AP 101 determines to suspend operation (YES in S1408), it ends communication processing.

[0055] (STA110 processing flow example) The processing flow of the STA 110 when performing communication using OFDMA with a DRU will be described. FIG. 15 shows an example of a processing flow when the STA 110 performs communication using UL MU OFDMA with the AP 101. This operation flow can be executed by the control unit 1202 in the STA 110 reading and executing a computer program stored in the storage unit 1201. First, the STA 110 notifies the AP 101 of the data accumulation status (S1501). For example, when the STA 110 receives a BSRP from the AP 101 that includes the STA 110 as a destination, the STA 110 can notify the AP 101 of the data accumulation status of the STA 110 by transmitting a BSR to the AP 101 in response to the BSRP. Based on the data accumulation status notified by each STA 110, the AP 101 determines whether to perform communication using UL MU OFDMA. Based on the data accumulation status notified by each STA 110, the AP 101 also determines the communication method to be used in UL MU OFDMA and allocates RUs to each STA 110. Then, the AP 101 transmits a Trigger frame including the communication method used in UL MU OFDMA and allocation information of the RUs allocated to each STA 110. When the STA 110 receives the Trigger frame (YES in S1502), it acquires information indicating the communication method used in UL MU OFDMA and the allocation information of the RUs allocated to each STA 110, which is included in the Trigger frame (S1503). The STA 110 also identifies the subcarriers allocated to its own device based on this information (S1504). Note that if the STA 110 does not receive a Trigger frame from the AP 101 (NO in S1502), it may terminate the process. The STA 110 may acquire the RU type and RU index of the RU allocated to its own device from the RU allocation information included in the Trigger frame. Based on this information and information indicating whether a DRU or a CRU is being used, STA110 can identify the subcarrier that it should use by associating the RU index with the subcarrier index or the DRU subcarrier index shown in Figures 3 and 6.For example, when the STA 110 indicates that it will use a DRU (YES in S1504), it may identify a subcarrier to be used by the STA 110 based on the correspondence between the RU index and the DRU subcarrier index (S1505). For example, when the STA 110 indicates that it will use a CRU (NO in S1504), it may identify a subcarrier to be used by the STA 110 based on the correspondence between the RU index and the subcarrier index (S1506). Then, in order to transmit a PPDU, the STA 110 sets communication parameters according to the communication method used for UL MU OFDMA (S1507) and transmits a data frame (S1508). In this embodiment, it is assumed that the data frame transmitted in S1508 includes, for example, an A-MPDU in which one or more data-type MAC frames are concatenated in the payload of a UHR PPDU. More specifically, it is assumed that the data includes a MAC frame of a QoS data type that stores data classified into one of four access categories: AC_BK, AC_BE, AC_VI, and AC_VO. Note that A-MPDU stands for Aggregate MPDU, and MPDU stands for MAC Protocol Data Unit. However, this is not limited to this, and the A-MPDU of the UHR TB PPDU transmitted in S1508 may include a management frame or a control frame. For example, the STA 101 sets communication parameters so that data is transmitted using the subcarrier identified as the subcarrier to be used by the STA 101. The data transmitted from each STA 110 is received by the AP 101. If the reception process is successful, the AP 101 transmits an acknowledgment to the STA 110 indicating that the data was received successfully. If the reception process is not successful, the AP 101 may transmit an acknowledgment to the STA 110 indicating that the data was not received successfully. If the STA 110 receives an acknowledgment and the data frame is received normally (YES in S1509), the STA 110 ends the communication process. If the data frame is not received normally because the STA 110 does not receive an acknowledgment or the like (NO in S1509), the STA 110 saves the transmitted data in a retransmission buffer and ends the communication process (S1510).In this case, the STA 110 may return to S1501 and continue the process to retransmit the data.

[0056] (Variation) The above description uses an example in which one PPDU performs either OFDMA communication using a DRU or OFDMA communication using a CRU. In this modification, an example is described in which one PPDU performs both radio resource allocation using a DRU and radio resource allocation using a CRU. The radio resources may be the respective subcarriers. For example, when communicating using a wide-bandwidth PPDU, the AP 101 may divide one PPDU into multiple bands on the frequency axis and select radio resource allocation using a DRU or radio resource allocation using a CRU for each band. For example, when communicating using a PPDU with a 160-MHz bandwidth, the AP 101 may divide one PPDU into two bands with a bandwidth of 80 MHz. Furthermore, when communicating using a PPDU with a 320-MHz bandwidth, the AP 101 may divide one PPDU into four bands with a bandwidth of 80 MHz. For example, suppose the AP 101 divides a 160 MHz bandwidth PPDU into two bands, forming a first band with a higher frequency and a second band with a lower frequency. In this case, there may be a total of four combinations of RUs used for allocation in the first band and RUs used for allocation in the second band. For example, allocation using a DRU may be performed in the first band, and allocation using a CRU may be performed in the second band. For example, allocation using a CRU may be performed in the first band, and allocation using a DRU may be performed in the second band. For example, allocation using a DRU may be performed in both the first band and the second band. For example, allocation using a CRU may be performed in both the first band and the second band. The AP 101 may notify the STA 110 of the combination of RUs to be allocated and communication based on that allocation. For example, the AP 101 may use a Trigger frame to notify the STA 110 of the combination of RUs to be allocated and communication based on that allocation.

[0057] The AP 101 also allocates RUs to each STA 110 in each band. The AP 101 may allocate RUs using an RU allocation pattern corresponding to the bandwidth of each band. For example, if a PPDU with a bandwidth of 160 MHz is divided into two bands with a bandwidth of 80 MHz, the AP 101 may allocate RUs in each 80 MHz band using an RU allocation pattern corresponding to the 80 MHz bandwidth. As an example, when the AP 101 allocates DRUs in a first band of 80 MHz, the AP 101 may allocate DRUs using the RU allocation pattern corresponding to the 80 MHz bandwidth shown in FIG. 6. As an example, when the AP 101 allocates CRUs in a second band of 80 MHz, the AP 101 may allocate CRUs using the RU allocation pattern corresponding to the 80 MHz bandwidth shown in FIG. 3. The AP 101 may notify each STA 110 of information regarding the allocation of RUs. For example, the AP 101 can use the Trigger frame to notify information that can identify the bandwidth of the PPDU, whether to use a DRU or a CRU in each band when the band is divided, and so on.

[0058] An example of the configuration of a Trigger frame used by the AP 101 to notify the STA 110 when radio resource allocation using a DRU and radio resource allocation using a CRU are mixed will be described with reference to FIG. 9 . The AP 101 may use the User Info field 909 to notify each STA 110 of information that can identify whether or not a DRU is used, the assigned RU, and the assigned band. For example, the AID12 subfield 911 of the User Info field 909 identifies the target STA 110. The AP 101 may use the DRU 919 subfield to indicate whether or not allocation using a DRU is to be performed for that STA 110. That is, the AP 101 may indicate that communication with that STA 110 will be performed using OFDMA using a DRU by setting a specific value in the DRU 919 subfield. For example, setting a value of 1 in the DRU 919 subfield indicates that communication will be performed using OFDMA using a DRU. Furthermore, when a value of 0 is set in the DRU 919 subfield, it may indicate that communication is performed using OFDMA with a CRU. Furthermore, when a value of 0 is set in the DRU 919 subfield, it may indicate that communication is performed using another communication method. Furthermore, the AP 101 may use the RU Allocation subfield 912 to notify the STA 110 of the RU type and RU index of the RU allocated to the STA 110. Here, the AP 101 may use the RU Allocation subfield 912 to indicate the band of the RU allocated to the STA 110. For example, when dividing a PPDU with a bandwidth of 160 MHz into two bands with a bandwidth of 80 MHz, the AP 101 may use the RU Allocation subfield 912 to indicate in which of the first band and the second band the RU has been allocated. Furthermore, the AP 101 may use other fields, such as the Reserved subfield 915 or the PS160 subfield 918, to indicate the band to which the RU has been allocated. The AP 101 may also provide a new subfield in the User Info field 909 to indicate the band in which the STA 110 is assigned an RU.For example, the AP 101 may use the band index shown in FIG. 7 to indicate the band to which the allocation was made. In this way, the User Info field 909 indicates the band to which the RU was allocated, the RU type, the RU index, and whether it is a DRU or a CRU for each STA 110, so that the STA 110 can identify the subcarriers to be used by the STA 110. The AP 101 may also use the Common Info field 905 to indicate information indicating whether a DRU is used in each divided band. In this case, the STA 110 may identify the band allocated to the STA 110 based on which divided bandwidth the DRU is used in. For example, assume that the Common Info field 905 indicates that a DRU is used in the first band, and the DRU subfield 919 indicates that an allocation using a DRU has been made to the STA 110. In this case, by combining this information, STA 110 can determine that an RU has been allocated to itself in the first band, even if the band of the RU allocated to itself is not explicitly stated. Furthermore, even when the band of the PPDU is divided into multiple bands, AP 101 can set RU indices so that RUs can be uniquely identified throughout the PPDU. For example, when a PPDU with a bandwidth of 160 MHz is divided into two 80 MHz bands on the frequency axis and DRUs are allocated using 26-tone RUs in each band, RU indices RU1 to RU37 can be assigned to each band. In this case, the RU indices in the lower frequency band may be RU1 to RU37, and the RU indices in the higher frequency band may be RU38 to RU74. This eliminates the need to separately notify STA 110 of information indicating the band to which the RU has been allocated.

[0059] The AP 101 may use the Common Info field 905 to notify the STA 110 of information that can identify the bandwidth of the PPDU and the band using the DRU. For example, in the configuration of the Common Info field 905 shown in FIG. 10 , the AP 101 may use the Trigger Type subfield 1001 to indicate whether or not to perform OFDMA communication using a DRU. In this case, the AP 101 may set a specific value in the Trigger Type subfield 1001 when performing OFDMA communication using a DRU and when performing OFDMA communication using a DRU and a CRU. For example, the AP 101 may set a specific value (e.g., a value of 9) in the Trigger Type subfield 1001 when performing OFDMA communication using a DRU in at least a part of the band of the PPDU. Furthermore, the AP 101 may indicate the bandwidth of the PPDU in the UL BW subfield 1005. Furthermore, the AP 101 may indicate the number of divisions of the band and whether to use a DRU or a CRU in each band. For example, the AP 101 may use the Trigger Dependent Common Info subfield 1019 to indicate the number of band divisions and whether a DRU or a CRU is to be used in each band. For example, the AP 101 may indicate, in a bitmap representation, whether a DRU or a CRU is to be used in each band formed by the division, by providing bits corresponding to the number of band divisions. For example, if a DRU is to be used in a first band, the value of the bit corresponding to the first band may be set to 1. Also, if a CRU is to be used in a second band, the value of the bit corresponding to the second band may be set to 0. Also, the AP 101 may indicate, in decimal notation, whether a DRU or a CRU is to be used in each band. For example, if a CRU is to be used in both the first band and the second band, the value of 0 may be set. For example, if a DRU is to be used in the first band and a CRU is to be used in the second band, the value of 1 may be set. For example, if a CRU is to be used in the first band and a DRU is to be used in the second band, the value of 2 may be set. For example, if DRUs are used in both the first band and the second band, a value of 3 may be set.Similarly, when the number of divisions is three or more, whether a DRU or a CRU is used in each band can be indicated by a bitmap representation or a decimal representation. The method of indicating information that can identify the bandwidth of the PPDU and the band in which the DRU is used is not limited to these. For example, the AP 101 can indicate the information by using Reserved subfields 1007, 1009, 1015, 1018, etc. The AP 101 may also provide a new field in the Common Info field 905 for indicating information that can identify the bandwidth of the PPDU and the band in which the DRU is used. The AP 101 may also notify this information by including it in each User Info field 909.

[0060] The operations of the AP 101 and the STA 110 when radio resource allocation using DRUs and radio resource allocation using CRUs are mixed will be described with reference to FIG. 8. The AP 101 obtains the amount of data accumulated in each STA 110 by exchanging frames in F801 and F802, and allocates RUs to each STA 110. The AP 101 determines the allocation of RUs to each STA 110 and the communication method to be used, and notifies them using a Trigger frame (F803). For example, the AP 101 can notify that it will perform OFDMA communication using DRUs in at least some bands by setting a specific value in the Trigger Type subfield 1001. Note that when notifying that it will use DRUs in at least some bands in another area of ​​the frame, the AP 101 can set a value indicating that it is a Basic Trigger frame in the Trigger Type subfield 1001. The AP 101 may use the Common Info field 905 to notify information that can identify the bandwidth of the PPDU and whether a DRU or a CRU is used in each band formed by division. For example, the AP 101 may use the UL BW subfield 1005 to indicate the bandwidth of the PPDU. The AP 101 may also include in the Common Info field 905 a field that indicates information that can identify whether a DRU or a CRU is used in each band, using a bitmap representation, a decimal representation, or the like. The AP 101 may use the User Info field 909 to indicate the allocation of RUs to each STA 110 and whether a DRU or a CRU is used for OFDMA communication. For example, the AP 101 may use the RU Allocation subfield 912 to indicate allocation information of RUs allocated to the STA 110. For example, the AP 101 may use the DRU subfield 919 to indicate whether a DRU or a CRU was used to allocate the RU, as well as the RU type and RU index. In addition, the AP 101 may include information indicating the RU bandwidth allocated to the STA 110 in the User Info field 909.In addition, the AP 101 may indicate whether the STA 110 will use the DRU or CRU for OFDMA communication by combining information indicating the band to which the STA 110's RU is allocated and information indicating whether the DRU or CRU will be used in that band. In this case, the DRU subfield 919 may be omitted from the User Info field 909.

[0061] The STA 110 determines the communication scheme and subcarriers to be used by the STA 110 based on the received Trigger frame. For example, if the Trigger Type subfield 1001 indicates that the Trigger frame is a DRU-variant Trigger frame, the STA 110 may determine that OFDMA communication using a DRU is to be performed in at least a portion of the PPDU. Furthermore, the STA 110 may determine whether a DRU or a CRU is to be used in the bandwidth of the PPDU or in each band formed by division, based on the values ​​set in the respective subfields included in the Common Info subfield 905. Furthermore, the STA 110 may determine whether a DRU or a CRU is to be used for OFDMA communication and may also identify the subcarriers allocated to the STA 110 based on the values ​​set in the respective subfields included in the User Info field 909. For example, the STA 110 may identify the RUs allocated to the STA 110 based on information that can identify the RU type and RU index and information indicating the band, which are included in the RU Allocation subfield 912. The STA 110 may then identify the subcarriers to be used by the STA 110 based on information indicating whether the allocation was performed using the DRU or the CRU and information indicating the RU allocated to the STA 110. For example, the STA 110 may identify the subcarriers to be used by the STA 110 based on the correspondence between the RU index and the subcarrier index or the DRU subcarrier index as shown in FIG. 3 or FIG. 6. The STA 110 may transmit data using the identified subcarriers (F804). The AP 101 acknowledges receipt of data from each STA 110 via the corresponding subcarrier (F805). This configuration allows the AP 101 to configure a Trigger frame so that communication is performed in a single PPDU, with a mixture of RU allocations using the DRU and RU allocations using the CRU. This enables parallel communication with STAs in an environment where both STAs capable of performing OFDMA using the DRU and STAs incapable of performing OFDMA using the DRU coexist, thereby enabling efficient use of radio resources.

[0062] As described above, according to this embodiment, when communicating data frames with the STA 110 using OFDMA with a DRU, the AP 101 transmits a predetermined frame set with a specific value indicating the use of a DRU. After transmitting the predetermined frame, the AP 101 communicates data frames with the STA 110 using the communication method indicated in the predetermined frame. This configuration allows the communication devices to share the communication method to be used before communicating data frames using OFDMA with a DRU or a CRU. This allows the communication devices to mutually recognize the communication method to be used, even when they are capable of both OFDMA communication with a CRU and OFDMA communication with a DRU, thereby enabling flexible selection of the communication method according to the situation.

[0063] In the present embodiment, a DRU is used to describe an RU configured with multiple subcarriers arranged such that at least some of the subcarriers are discontinuous on the frequency axis. A CRU is used to describe an RU configured with multiple subcarriers arranged so that they are contiguous on the frequency axis. These may be referred to by other names. The Trigger frame has been used as an example of a frame for notifying the AP 101 of the communication scheme to be used and information about the RUs assigned to each STA 110. Other frames may be used as frames for notifying the AP 101 of the communication scheme to be used and information about the RUs assigned to each STA 110. The Trigger frame also includes an example in which various pieces of information are notified using the Common Info field 905, the User Info field 909, and the like. This information may be notified using other fields or subfields, and the names used in the present embodiment may be referred to by other names. While examples showing the relationships between bandwidth, RU type, RU index, subcarrier index, and the like have been described with reference to FIGS. 3 and 6, these are merely examples, and OFDMA using a DRU or an OFDMA using a CRU with different configurations may also be performed.

[0064] 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.

[0065] (Summary of the embodiment) At least some of the above-described embodiments can be summarized as follows. (Item 1) A communication device that performs communication in accordance with the IEEE 802.11 series standard with another communication device, The communication device has a communication means capable of performing communication using a first communication method in which radio resources are allocated using at least two or more first-type resource units (RUs), each RU being made up of a plurality of subcarriers arranged so that at least some of the subcarriers are discontinuous on a frequency axis, and data is communicated using the radio resources by orthogonal frequency division multiple access (OFDMA), and a second communication method in which radio resources are allocated using at least two or more second-type RUs, each RU being made up of a plurality of subcarriers arranged so that they are contiguous on a frequency axis, and data is communicated using the radio resources by OFDMA, The communication means is When communicating a data frame with the other communication device using the first communication method, a predetermined frame in which a specific value indicating that the first communication method will be used is transmitted to the other communication device, thereby indicating that the first communication method will be used; When communicating a data frame with the other communication device using the second communication method, the predetermined frame in which the specific value is not set is transmitted to the other communication device, thereby indicating to the other communication device that the second communication method will be used; After transmitting the predetermined frame, the communication device communicates data frames with the other communication device using the communication method indicated by the predetermined frame. A communication device comprising: (Item 2) The communication means is The other communication device transmits the predetermined frame further including identification information that can identify the RU assigned to the other communication device; The communication device communicates data frames with the other communication device using a subcarrier to be used by the other communication device, the subcarrier being specified based on whether the specific value is set and the specific information. 2. The communication device according to item 1, (Item 3) A communication device that performs communication in accordance with the IEEE 802.11 series standard with another communication device, The communication device has a communication means capable of performing communication using a first communication method in which radio resources are allocated using at least two or more first-type resource units (RUs), each RU being made up of a plurality of subcarriers arranged so that at least some of the subcarriers are discontinuous on a frequency axis, and data is communicated using the radio resources by orthogonal frequency division multiple access (OFDMA), and a second communication method in which radio resources are allocated using at least two or more second-type RUs, each RU being made up of a plurality of subcarriers arranged so that they are contiguous on a frequency axis, and data is communicated using the radio resources by OFDMA, The communication means is when a predetermined frame in which a specific value indicating that the first communication method is used is set is received from the other communication device, after receiving the predetermined frame, a data frame is communicated with the other communication device using the first communication method; When the predetermined frame in which the specific value is not set is received from the other communication device, after receiving the predetermined frame, the communication device communicates a data frame with the other communication device using the second communication method. A communication device comprising: (Item 4) The predetermined frame further includes identification information that enables the communication device to identify the RU assigned to the communication device; The communication means communicates data frames with the other communication device using a subcarrier to be used by the communication device specified based on whether the specific value is set and the specific information. 4. The communication device according to item 3, (Item 5) The predetermined frame is a Trigger frame. 5. The communication device according to any one of items 1 to 4, (Item 6) The predetermined value is set in a predetermined region in the predetermined frame. 6. The communication device according to any one of items 1 to 5, (Item 7) The predetermined area is a User Info field. 7. The communication device according to item 6, (Item 8) The predetermined area is a Common Info field. 7. The communication device according to item 6, (Item 9) The predetermined area is a Trigger Type subfield included in the Common Info field. 9. The communication device according to item 8, (Item 10) A communication method executed by a communication device that executes communication conforming to the IEEE 802.11 series standard with another communication device, comprising: The method includes a communication process capable of performing communication using a first communication method in which radio resources are allocated using at least two or more first-type resource units (RUs), each RU being made up of a plurality of subcarriers arranged so that at least some of the subcarriers are discontinuous on a frequency axis, and data is communicated using the radio resources by orthogonal frequency division multiple access (OFDMA); and a second communication method in which radio resources are allocated using at least two or more second-type RUs, each RU being made up of a plurality of subcarriers arranged so that they are contiguous on a frequency axis, and data is communicated using the radio resources by OFDMA, The communication step includes: When communicating a data frame with the other communication device using the first communication method, a predetermined frame in which a specific value indicating that the first communication method will be used is transmitted to the other communication device, thereby indicating that the first communication method will be used; When communicating a data frame with the other communication device using the second communication method, the predetermined frame in which the specific value is not set is transmitted to the other communication device, thereby indicating to the other communication device that the second communication method will be used; After transmitting the predetermined frame, the communication device communicates data frames with the other communication device using the communication method indicated by the predetermined frame. A communication method comprising: (Item 11) A communication method executed by a communication device that executes communication conforming to the IEEE 802.11 series standard with another communication device, comprising: The method includes a communication process capable of performing communication using a first communication method in which radio resources are allocated using at least two or more first-type resource units (RUs), each RU being made up of a plurality of subcarriers arranged so that at least some of the subcarriers are discontinuous on a frequency axis, and data is communicated using the radio resources by orthogonal frequency division multiple access (OFDMA); and a second communication method in which radio resources are allocated using at least two or more second-type RUs, each RU being made up of a plurality of subcarriers arranged so that they are contiguous on a frequency axis, and data is communicated using the radio resources by OFDMA, The communication step includes: when a predetermined frame in which a specific value indicating that the first communication method is used is set is received from the other communication device, after receiving the predetermined frame, a data frame is communicated with the other communication device using the first communication method; When the predetermined frame in which the specific value is not set is received from the other communication device, after receiving the predetermined frame, the communication device communicates a data frame with the other communication device using the second communication method. A communication method comprising: (Item 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 9. [Explanation of symbols]

[0066] 101:AP, 111:STA, 112:STA, 113:STA

Claims

1. A communication device that performs communication in accordance with the IEEE 802.11 series standard with another communication device, The present invention has a communication means capable of performing communication using a first communication method in which radio resources are allocated using at least two or more first-type resource units (RUs), each RU being made up of a plurality of subcarriers arranged so that at least some of the subcarriers are discontinuous on a frequency axis, and data is communicated using the radio resources by orthogonal frequency division multiple access (OFDMA), and a second communication method in which radio resources are allocated using at least two or more second-type RUs, each RU being made up of a plurality of subcarriers arranged so that they are contiguous on a frequency axis, and data is communicated using the radio resources by OFDMA, The communication means is When communicating a data frame with the other communication device using the first communication method, a predetermined frame in which a specific value indicating that the first communication method will be used is transmitted to the other communication device, thereby indicating that the first communication method will be used; When communicating a data frame with the other communication device using the second communication method, the predetermined frame in which the specific value is not set is transmitted to the other communication device, thereby indicating to the other communication device that the second communication method will be used; After transmitting the predetermined frame, the communication device communicates data frames with the other communication device using the communication method indicated by the predetermined frame. A communication device comprising:

2. The communication means is The other communication device transmits the predetermined frame further including identification information that can identify the RU assigned to the other communication device; The communication device communicates data frames with the other communication device using a subcarrier to be used by the other communication device, the subcarrier being specified based on whether the specific value is set and the specific information.

2. The communication device according to claim 1.

3. A communication device that performs communication in accordance with the IEEE 802.11 series standard with another communication device, The present invention has a communication means capable of performing communication using a first communication method in which radio resources are allocated using at least two or more first-type resource units (RUs), each RU being made up of a plurality of subcarriers arranged so that at least some of the subcarriers are discontinuous on a frequency axis, and data is communicated using the radio resources by orthogonal frequency division multiple access (OFDMA), and a second communication method in which radio resources are allocated using at least two or more second-type RUs, each RU being made up of a plurality of subcarriers arranged so that they are contiguous on a frequency axis, and data is communicated using the radio resources by OFDMA, The communication means is when a predetermined frame in which a specific value indicating that the first communication method is used is set is received from the other communication device, after receiving the predetermined frame, a data frame is communicated with the other communication device using the first communication method; When the predetermined frame in which the specific value is not set is received from the other communication device, after receiving the predetermined frame, the second communication method is used to communicate a data frame with the other communication device. A communication device comprising:

4. the predetermined frame further includes identification information that enables the communication device to identify an RU assigned to the communication device; The communication means communicates data frames with the other communication device using a subcarrier to be used by the communication device specified based on whether the specific value is set and the specific information.

4. The communication device according to claim 3.

5. The predetermined frame is a Trigger frame.

4. The communication device according to claim 1, wherein the first and second communication devices are connected to each other.

6. The predetermined value is set in a predetermined region in the predetermined frame.

4. The communication device according to claim 1, wherein the first and second communication devices are connected to each other.

7. The predetermined area is the User Info field.

7. The communication device according to claim 6.

8. The predetermined area is a Common Info field.

7. The communication device according to claim 6.

9. The predetermined area is a Trigger Type subfield included in the Common Info field.

9. The communication device according to claim 8.

10. A communication method executed by a communication device that executes communication compliant with the IEEE 802.11 series standard with another communication device, comprising: The method includes a communication process capable of performing communication using a first communication method in which radio resources are allocated using at least two or more first-type resource units (RUs), each RU being made up of a plurality of subcarriers arranged so that at least some of the subcarriers are discontinuous on a frequency axis, and data is communicated using the radio resources by orthogonal frequency division multiple access (OFDMA); and a second communication method in which radio resources are allocated using at least two or more second-type RUs, each RU being made up of a plurality of subcarriers arranged so that they are contiguous on a frequency axis, and data is communicated using the radio resources by OFDMA, The communication step includes: When communicating a data frame with the other communication device using the first communication method, a predetermined frame in which a specific value indicating that the first communication method will be used is transmitted to the other communication device, thereby indicating that the first communication method will be used; When communicating a data frame with the other communication device using the second communication method, the predetermined frame in which the specific value is not set is transmitted to the other communication device, thereby indicating to the other communication device that the second communication method will be used; After transmitting the predetermined frame, the communication device communicates data frames with the other communication device using the communication method indicated by the predetermined frame. A communication method comprising:

11. A communication method executed by a communication device that executes communication compliant with the IEEE 802.11 series standard with another communication device, comprising: The method includes a communication process capable of performing communication using a first communication method in which radio resources are allocated using at least two or more first-type resource units (RUs), each RU being made up of a plurality of subcarriers arranged so that at least some of the subcarriers are discontinuous on a frequency axis, and data is communicated using the radio resources by orthogonal frequency division multiple access (OFDMA); and a second communication method in which radio resources are allocated using at least two or more second-type RUs, each RU being made up of a plurality of subcarriers arranged so that they are contiguous on a frequency axis, and data is communicated using the radio resources by OFDMA, The communication step includes: when a predetermined frame in which a specific value indicating that the first communication method is used is set is received from the other communication device, after receiving the predetermined frame, a data frame is communicated with the other communication device using the first communication method; When the predetermined frame in which the specific value is not set is received from the other communication device, after receiving the predetermined frame, the second communication method is used to communicate a data frame with the other communication device. A communication method comprising:

12. A program for causing a computer to function as each of the means included in the communication device according to claim 1 or 3.

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