WO2025234239A1 - Communication device, communication method, and program - Google Patents

Abstract

This communication device, which performs communication conforming to the IEEE 802.11 standard series with another communication device: executes communication using a plurality of communication methods, including a first communication method in which a wireless resource is allocated using at least two or more first-type resource units (RUs) configured from a plurality of sub-carriers disposed consecutively on a frequency axis and in which data is communicated through orthogonal frequency division multiple access (OFDMA) using the wireless resource, and a second communication method in which the wireless resource is allocated using at least two or more second-type RUs configured from a plurality of sub-carriers disposed such that at least some of the sub-carriers are not consecutive on the frequency axis and in which data is communicated through OFDMA using the wireless resource; receives, from the other communication device, a prescribed wireless frame including prescribed capability information indicating whether the other communication device has a prescribed capability to execute communication using the second communication method; performs communication with the other communication device using either one of the first communication method or the second communication method in cases in which the other communication device has the prescribed capability when an OFDMA-based communication method is used in communication with the other communication device; and performs communication with the other communication device using the first communication device in cases in which the other communication device does not have the prescribed capability.

Description

Communication device, communication method, and program

The present invention relates to technology for wireless communication using orthogonal frequency division multiple access (OFDMA) that complies with the IEEE 802.11 standard.

In recent years, with the increase in the amount of data being communicated, development of communication technologies such as wireless LANs (Local Area Networks) has been progressing. The IEEE (Institute of Electrical and Electronics Engineers) 802.11 standard series is known as the main communication standard for wireless LANs. The IEEE 802.11 standard series includes the IEEE 802.11a/b/g/n/ac/ax/be standards, among others. In order to further improve communication reliability, development is underway on the IEEE 802.11bn standard as the successor to the IEEE 802.11be standard. In the IEEE 802.11 Working Group (WG), which is formulating the IEEE 802.11bn standard, the UHR SG will determine the standard's goals and scope of study, while TGbn will specify the detailed technical content to be included in the standard. UHR SG is an abbreviation for Ultra High Reliability Study Group. TGbn is an abbreviation for Task Group bn.

The IEEE 802.11 standard series 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, 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). The access point (AP) assigns each RU to each station (STA), allowing communication to take place in parallel between the AP and multiple STAs. This improves frequency utilization efficiency for the entire communication system.

Meanwhile, in recent years, many countries have been working to establish legal regulations allowing wireless LANs to use frequencies in the 6 GHz band. The availability of frequencies in the 6 GHz band will enable further improvements in wireless LAN throughput. However, the legally permitted transmit power density required when using the 6 GHz band is lower than that required for the 2.4 GHz and 5 GHz bands, which are frequency bands traditionally used for wireless LANs. Therefore, in formulating the IEEE 802.11bn standard, technologies are being considered for increasing transmit power while still meeting the legally permitted transmit power density when using the 6 GHz band. For example, Non-Patent Document 1 considers an OFDMA system in which wireless resources are allocated using RUs consisting of multiple subcarriers arranged so that at least some of the subcarriers are discontinuous on the frequency axis. Such RUs can be called Distributed Resource Units (DRUs).

Lin Yang et al., “High Level Thoughts on DUR Design (IEEE 802.11-23/1988r1)”, IEEE802.11, 2024

One aspect of the present invention is to provide technology that enables the efficient use of OFDMA in communications between access points and stations.

A communication device that communicates with other communication devices in accordance with the IEEE 802.11 standard series, comprising: a first communication method that allocates wireless resources using at least two or more first-type resource units (RUs) consisting of multiple subcarriers arranged contiguously on the frequency axis, and uses the wireless resources to communicate data using orthogonal frequency division multiple access (OFDMA); and a second communication method that allocates wireless resources using at least two or more second-type RUs consisting of multiple subcarriers arranged so that at least some of the subcarriers are discontinuous on the frequency axis, and uses the wireless resources to communicate data using OFDMA. and a receiving means for receiving from the other communication device a predetermined wireless frame including predetermined capability information indicating whether the other communication device has a predetermined capability to communicate using the second communication method, wherein when an OFDMA communication method is used in communication with the other communication device, if the other communication device has the predetermined capability, the communication means communicates with the other communication device using either the first communication method or the second communication method, and if the other communication device does not have the predetermined capability, the communication means communicates with the other communication device using the first communication method.

One aspect of the present invention enables the efficient use of OFDMA in communications between access points and stations.

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

The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention.
FIG. 1 is a diagram showing an example of the configuration of a wireless communication system. FIG. 2 is a diagram showing an example of an arrangement pattern of RUs on the frequency axis in OFDMA. FIG. 3 is a diagram showing an example of the correspondence between RU indexes and subcarrier indexes in OFDMA. FIG. 4 is a diagram illustrating the concept of OFDMA using DRUs. FIG. 5 is a diagram showing an example of the correspondence between subcarrier indexes in a CRU and subcarrier indexes in a DRU. FIG. 6 is a diagram showing an example of the correspondence between RU indexes and subcarrier indexes in OFDMA using DRUs. FIG. 7 is a diagram showing an example of a method for arranging DRUs in a PPDU with a bandwidth of 160 MHz by repeating, on the frequency axis, an arrangement pattern of DRUs corresponding to a PPDU with a bandwidth of 80 MHz. FIG. 8 is a diagram showing an example of frame exchange performed between communication devices. FIG. 9 is a diagram illustrating an example of the hardware configuration of a communication device. FIG. 10 is a diagram illustrating an example of the functional configuration of an AP. FIG. 11 is a diagram illustrating an example of the functional configuration of the STA. FIG. 12 is a diagram showing an example of frame exchange performed between communication devices. FIG. 13 is a diagram showing an example of the UHR Capabilities element. FIG. 14 is a diagram illustrating an example of a processing flow executed by the communication device.

The following embodiments are described in detail with reference to the attached drawings. Note that the following embodiments do not limit the invention as defined by the claims. While the embodiments describe multiple features, not all of these features are necessarily essential to the invention, and multiple features may be combined in any desired manner. Furthermore, in the attached drawings, the same reference numbers are used to designate identical or similar components, and redundant explanations will be omitted.

(System configuration)
FIG. 1 shows an example configuration of a wireless communication system according to this embodiment. The wireless communication system includes, for example, an access point (AP) 101 and stations (STAs) 111 to 113. The AP may also be referred to as an AP STA. The STAs may also be referred to as non-AP STAs. In this embodiment, the STAs 111 to 113 may be collectively referred to as STA 110. The AP 101 and STA 110 may also be collectively referred to as communication device 100. The AP 101 and STA 110 are each communication devices capable of performing wireless communication compliant with the IEEE 802.11 standard series. IEEE stands for Institute of Electrical and Electronics Engineers. FIG. 1 shows a configuration in which the STAs 111 to 113 participate in a network 131 established by the AP 101. AP 101 and STA 111 are connected using wireless channel 121. AP 101 and STA 112 are connected using wireless channel 122. AP 101 and STA 113 are connected using wireless channel 123. Wireless channels 121 to 123 use the same frequency channel. Network 131 in FIG. 1 shows a configuration in which one AP 101 and three STAs 110 exist, but there may be multiple APs, or there may be one, two, 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.

In this embodiment, the communication device 100 is configured to be able to execute a communication method that complies with a successor standard to IEEE 802.11. For example, the communication device 100 is configured to be able to execute a communication method that complies with the IEEE 802.11bn standard. The IEEE 802.11bn standard is a successor standard to the IEEE 802.11be standard, which targets a maximum transmission speed of 46.08 Gbps (Giga bit per second). The main features of the IEEE 802.11bn standard are its functions for achieving highly reliable communication, low latency communication, improved throughput when communication traffic is congested, and reduced power consumption in APs. The IEEE 802.11bn standard is also known as the UHR standard. UHR is an abbreviation for Ultra High Reliability. The communication device 100 may communicate in accordance with a successor standard to the IEEE 802.11bn standard. The wireless frame used in communications between communication devices 100 that conforms to a successor standard to the IEEE 802.11be standard is sometimes 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 functions defined in the standard. This means that a different name may be assigned to this standard once the standard development work is complete. Similarly, the term IEEE 802.11bn may be assigned a different name once the standard development work is complete. Please note that this specification and the accompanying claims are essentially applicable to all successor standards to the IEEE 802.11be standard, including these cases.

Furthermore, the communication device 100 can support at least one of the legacy standards that predate the IEEE 802.11bn standard. In other words, the communication device 100 can communicate using the PPDU of the legacy standard. Legacy standards include, for example, the IEEE 802.11a/b/g/n/ac/ax/be standards. The communication device 100 may also support other communication standards such as Bluetooth (registered trademark), NFC, UWB, ZigBee, MBOA, etc. Note that UWB stands for Ultra Wide Band, and MBOA stands for Multi Band OFDM Alliance. Furthermore, NFC stands for Near Field Communication. UWB includes wireless USB, wireless 1394, WiNET, etc. The communication device 100 may also support communication standards such as wired LAN. The AP 101 may be, for example, but is not limited to, a wireless LAN router or a personal computer (PC). The STA 110 may be, for example, but is not limited to, a camera, tablet, smartphone, PC, mobile phone, video camera, wearable device such as smart glasses, etc. The STA 110 may be, for example, but is not limited to, an IoT (Internet of Things) sensor, a smart lock, a smart sensor, or other IoT device. The IoT sensor may be an acceleration sensor, a light sensor, a humidity sensor, etc. The AP 101 and the STA 110 may be information processing devices such as wireless chips that support the IEEE 802.11bn standard and are capable of transmitting and receiving UHR PPDUs. In this case, various controls can be performed by hardware circuits within the wireless chip. Additionally, the wireless chip can be configured so that various processes are executed by the cooperation of processors, memory, and hardware circuits such as ASIPs inside the chip. ASIP stands for Application-Specific Instruction Set Processor.

The communication device 100 may communicate using radio signals in frequency bands such as the 2.4 GHz band, 3.6 GHz band, 5 GHz band, 6 GHz band, and the 45 GHz band and 60 GHz band known as millimeter waves. The frequency bands used by the communication device 100 are not limited to these and may be, for example, the Sub1 GHz band. The communication device 100 may also communicate using 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, 4 MHz, etc. A 40 MHz frequency channel may be formed by combining two 20 MHz frequency channels. Additionally, an 80 MHz frequency channel can be formed by combining two 40 MHz frequency channels. An 80 MHz frequency channel may also be formed by combining four 20 MHz frequency channels. Similarly, frequency channels such as 160 MHz, 320 MHz, etc. can be formed by combining or combining multiple channels of narrower frequency bands.

The IEEE 802.11 series of standards specifies a function that increases communication speeds by performing multi-user (MU) communication, in which an AP multiplexes wireless resources between multiple STAs and communicates simultaneously. For example, an AP can communicate with multiple STAs in parallel using OFDMA. OFDMA stands for Orthogonal Frequency Division Multiple Access. In OFDMA, the data field of a PPDU transmitted using a frequency channel of a specified bandwidth is divided into multiple units on the frequency axis. The specified bandwidth can 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 can be assigned to a different STA. The AP and one or more STAs may communicate in parallel using 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 consisting of multiple STAs. The AP 101 may also communicate in parallel with multiple STAs using multi-user MIMO (Multiple-Input and Multiple-Output) communication. In this case, the AP has multiple antennas, and transmits different signals from each antenna using the same frequency channel. Each STA simultaneously receives the signals transmitted from each antenna, separates the signals, and decodes them. In MIMO communication, the propagation paths used for communication between the AP and each STA are spatially orthogonal. This spatial orthogonality allows the AP to communicate in parallel with multiple STAs within a single specified bandwidth. By performing multi-user communication in this way, the AP can communicate more data with each STA in the same time period than if it were not performing multi-user communication. OFDMA and multi-user MIMO can be used together.

The data field included in the PPDU is composed of one or more Orthogonal Frequency Division Multiplex (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 intervals of 78.125 kHz. 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 constituting each RU type may be 26, 52, 106, 242, 484, or 996, respectively. In this manner, the number of subcarriers constituting the RU may be indicated by the RU type. FIG. 2 shows an example of an RU arrangement pattern in which RUs of each RU type are arranged 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 with a predetermined bandwidth. In FIG. 2, the horizontal axis indicates frequency. For example, as an RU placement pattern on the frequency axis, in the case of a 26-tone RU, 37 RUs can be placed on the frequency axis. Furthermore, in the case of a 52-tone RU, a 106-tone RU, a 242-tone RU, a 484-tone RU, and a 996-tone RU, 16, 8, 4, 2, and 1 RU can be placed, respectively. Thus, depending on the RU type, the number of RUs that can be placed in a PPDU with the same bandwidth as the number of subcarriers that make up one RU differs. 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 can indicate the position of each RU on the frequency axis. Note that 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 can be arranged on the frequency axis. For example, 26-tone RUs with RU indexes 1 and 2, a 52-tone RU with RU index 2, and a 106-tone RU with RU index 2 can make up one PPDU.

Furthermore, each subcarrier included in the OFDM symbols constituting the 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 the subcarrier index for each of the 1,024 subcarriers. Figure 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 the 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. Conversely, 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. Figure 3 shows an example in which an RU with a small RU index value is configured using subcarriers with a small subcarrier index value, and an RU with a large RU index value is configured using subcarriers with a large subcarrier index value. In this way, when a specific RU is specified by 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. As a result, for example, when AP101 specifies an RU type and RU index, STA110 can identify the subcarrier index from the specified RU type and RU index and communicate using that subcarrier.

Note that subcarriers may include data subcarriers used for transmitting data, pilot subcarriers used for transmitting pilot signals, and unused subcarriers not used for any transmission. Unused subcarriers may include DC subcarriers, which are direct current (DC) components and subcarriers near them, guard band subcarriers at the edges of the frequency band occupied by the PPDU, and null subcarriers that are neither of these. For example, the subcarrier indices that make up RU19 of a 26-tone RU range from -16 to -4 and from 4 to 16. This RU is arranged across the DC subcarrier. For example, null subcarriers may be arranged between adjacent RUs. Note that 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. Note that the RU types, RU indices, and subcarrier indices applied 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 definitions of RU types, RU indices, and subcarrier indices corresponding to each PPDU bandwidth in the IEEE 802.11 standard series may be used. Additionally, for PPDUs with a bandwidth greater than 80 MHz, the RU placement may be such that the placement in the 80 MHz bandwidth is repeated multiple times for each 80 MHz band, as specified in the IEEE 802.11ax and IEEE 802.11be standards. In this case, the term DC subcarrier does not refer to the actual DC component of the PPDU and its adjacent subcarriers, but rather to the subcarriers located at and near the center of each 80 MHz band that makes up the PPDU.

As mentioned above, when an RU used in OFDMA is composed of subcarriers that are contiguous on the frequency axis, this RU can be called a Consecutive Resource Unit (CRU). A CRU may also be called a consecutive RU or a regular RU (rRU). A CRU can include multiple data subcarriers and pilot subcarriers that are contiguous on the frequency axis. In this embodiment, a middle 26-tone RU, such as RU19 of the 26-tone RU shown in Figure 3, in which the subcarriers that make up the RU are separated by a DC subcarrier but are composed of two groups of subcarriers that are adjacent on the frequency axis, is also called a CRU. A middle 26-tone RU is an RU that is formally separated by a DC subcarrier but is composed of subcarriers that can be considered substantially contiguous on the frequency axis. Here, OFDMA using a CRU can generally have a high transmit power density. A middle 26-tone RU, which uses a first group of 13 contiguous subcarriers and a second group of 13 adjacent subcarriers in the frequency domain, can also have a high transmit power density. Transmit power density is the transmit power per unit frequency. That is, OFDMA using a CRU uses contiguous subcarriers on the frequency axis, which concentrates transmit power in a specific bandwidth, resulting in a high transmit power density. However, because transmit power density is subject to legal restrictions in each country, transmissions cannot be made at power levels exceeding the allowable values. For example, because the allowable transmit power density is set low in the 6 GHz band, when communicating using OFDMA using a CRU in the 6 GHz band, the transmit power of each subcarrier can be low. This can make it difficult for signals to reach STAs located far from the AP. In contrast, distributing the subcarriers constituting an RU across a wide band may increase the transmission power of each subcarrier. For example, while maintaining the number of subcarriers constituting each RU, OFDMA communication may be performed using RUs configured with subcarriers, at least some of which are not contiguous on the frequency axis, and arranged across a wider frequency band than conventional CRUs. RUs configured in this manner may be called Distributed RUs (DRUs). DRUs may also be called Distributed RUs, Enhanced RUs, or the like. Note that contiguous subcarriers on the frequency axis may refer to subcarriers with contiguous subcarrier indices among the subcarriers included in the OFDM symbols constituting the PPDU. Furthermore, contiguous subcarriers on the frequency axis may refer to subcarriers with contiguous subcarrier indices, excluding subcarrier indices assigned to unused subcarriers. Regardless of the assignment of information identifying each subcarrier, such as a subcarrier index, contiguous subcarriers on the frequency axis can be a set of subcarriers spaced at a predetermined interval from low to high frequency or from high to low frequency. Here, the frequency interval between contiguous subcarriers on the frequency axis is the reciprocal of the length of the effective symbol contained in the OFMD symbol. For example, if the effective symbol length is the same as in the IEEE 802.11ax or IEEE 802.11be standard, it is 78.125 kHz. In the following description, an RU consisting of multiple subcarriers arranged contiguously on the frequency axis is referred to as a CRU, and an RU consisting of multiple subcarriers arranged so that at least some of the subcarriers are discontinuous on the frequency axis is referred to as a DRU. However, an RU may be composed of only two groups of contiguous subcarriers on the frequency axis, with the constituent subcarriers separated by a DC subcarrier, as in RU19 of the 26-tone RU shown in Figure 3. In this case, because the transmission power density is high, it is considered to be essentially composed of continuous subcarriers on the frequency axis, and is referred to as a CRU rather than a DRU. In other words, the subcarriers that make up the DRU of this embodiment are more dispersed than those of the CRU's Middle-26 Tone RU19. When using a DRU, the signal transmitted by a single STA to its surroundings is dispersed in the frequency domain, as shown in Figure 4 below. As mentioned above, this dispersion has the effect of lowering the transmission power density emitted by the STA. Therefore, even if the power level of each subcarrier on which data is superimposed is set to a higher power level than that of a CRU with a higher density in the frequency domain, OFDMA can be performed with a transmission power density within the legally permitted limits.

The relationship between frequency domain dispersion and reduction in transmit power density is explained using Figure 4. Figure 4 shows the concept of OFDMA using DRUs. In Figure 4, STA111 to STA113 transmit data to AP101 using OFDMA using DRUs. For example, STA111 to STA113 each transmit using a DRU assigned by AP101. Assume that DRUs 401 to 403 are assigned to STA111 to STA113, respectively. For example, DRU 401 may be composed of subcarriers that are not contiguous with each other. In DRU 401, each of the subcarriers that make up the DRU may be arranged so that they are dispersed across the bandwidth of the PPDU. The subcarriers that make up DRUs 402 and 403 may be arranged in a similar manner. Note that some of the subcarriers that make up each DRU may be contiguous on the frequency axis. At least some of the subcarriers may be arranged so as not to be contiguous on the frequency axis, thereby reducing the transmission power density. Furthermore, the subcarriers constituting DRU 401 and DRU 402 are set so as not to overlap on the frequency axis. Similarly, the subcarriers constituting DRU 401 and DRU 403 do not overlap on the frequency axis, and the subcarriers constituting DRU 402 and DRU 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 AP 101 without interfering with each other, and the transmission power density of signals transmitted from each STA 110 can be reduced. The received signal at AP 101 is a combination of DRUs 401 to 403 assigned to STA 111 to STA 113 on the frequency axis. Figure 4 conceptually illustrates the combined signal 404. Note that in Figure 4, the arrangement of subcarriers constituting each DRU 401-403 is conceptual for illustrative purposes only, and the actual arrangement of subcarriers may vary. The number of subcarriers constituting a DRU and their arrangement pattern may be regular or irregular. For example, the number of subcarriers constituting a DRU and their arrangement pattern may be shared in advance between the AP 101 and each STA 110. When the AP 101 performs communication, it notifies each STA 110 of information that can identify the arrangement of subcarriers constituting the DRU to be assigned, so that the STA 110 can identify the arrangement on the frequency axis of the subcarriers constituting the DRU that it should use. For example, the AP 101 may use a trigger frame to notify the STA 110 of information that can identify the arrangement of subcarriers constituting the DRU that it should use.

In this way, by distributing each of the subcarriers constituting an RU across a wide frequency band, the transmission power density is lowered, allowing communication device 110 to transmit by setting the transmission power of each subcarrier high. However, when an AP and a STA attempt to communicate using OFDMA, communication is not possible if the configuration of the RUs available to each device is different. For example, if the AP can use a DRU and the STA can use a CRU, communication using OFDMA is not possible between these communication devices because the configuration of the RUs available to each device is different. Furthermore, when an AP attempts to communicate using OFDMA with multiple STAs, if the configuration of the RUs available to each STA is different, interference may occur between the respective communications. For example, if AP 101 uses a CRU with STA 111 and a DRU with STA 112 to communicate using OFDMA in the same frequency band, the CRU of STA 111 and the DRU of STA 112 may use the same subcarriers. In this case, interference may occur in the subcarriers used by both STA111 and STA112. Thus, in an environment where both a CRU and a DRU can be used, if the configuration of the RUs available to each communication device is different, communication using OFDMA is not possible. Furthermore, communication is not possible if the configuration of the RUs available to each communication device is unknown.

In consideration of these circumstances, the communication device in this embodiment acquires specified capability information indicating whether the other communication device has the specified capability to execute OFDMA using a DRU, and performs communication using OFDMA based on the other communication device's capability information. Alternatively, the communication device in this embodiment performs communication using OFDMA based on notifying the other communication device that it has the specified capability to execute OFDMA using a DRU. For example, the communication device may perform communication using a first communication method using OFDMA, in which radio resources are allocated using at least two or more first-type RUs consisting of multiple subcarriers arranged contiguously on the frequency axis. The first-type RU may be a CRU. The communication device may also perform communication using a second communication method using OFDMA, in which radio resources are allocated using at least two or more second-type RUs consisting of multiple subcarriers arranged so that at least some of the subcarriers are discontinuous on the frequency axis. The second-type RU may be a DRU. A communication device may perform communication using a plurality of communication methods including a first communication method and a second communication method. The communication device receives a predetermined radio frame from a counterpart communication device, the predetermined radio frame including predetermined capability information indicating whether the counterpart communication device has a predetermined capability to perform communication using the second communication method. When the communication device uses an OFDMA communication method for communication with the counterpart communication device, if the counterpart communication device has the predetermined capability, the communication device performs communication with the counterpart communication device using either the first communication method or the second communication method. When the counterpart communication device does not have the predetermined capability, the communication device performs communication with the counterpart communication device using the first communication method. Alternatively, the communication device transmits a predetermined radio frame to the counterpart communication device, the predetermined capability information indicating whether the communication device has a predetermined capability to perform communication using the second communication method. When the communication device uses an OFDMA communication method for communication with the counterpart communication device, if the communication device transmits the predetermined capability information to the counterpart communication device, the communication device performs communication with the counterpart communication device using either the first communication method or the second communication method. Furthermore, if the communication device has not transmitted predetermined capability information to the other communication device, it communicates with the other communication device using the first communication method. With this configuration, the communication device can communicate using OFDMA with a DRU based on the other communication device's ability to perform OFDMA with a DRU. Alternatively, the communication device can communicate using OFDMA with a DRU based on the other communication device's notification of its capability to perform OFDMA with a DRU to the other communication device. This makes it possible to select an appropriate communication method and perform OFDMA communication even in an environment where communication devices capable of performing OFDMA with a CRU and communication devices capable of performing OFDMA with a DRU are mixed. The device configuration, functional configuration, and processing examples of a communication device that performs such operations are described below.

(Example of DRU configuration)
First, an example of the 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 a 26-tone RU, a 52-tone RU, a 106-tone RU, a 242-tone RU, and a 484-tone RU. The number of subcarriers constituting each DRU of each RU type may be 26, 52, 106, 242, and 484, respectively.

Furthermore, in the case of OFDMA using DRUs, the number of DRUs arranged on the frequency axis to form a PPDU of a particular bandwidth may be the same as the number of CRUs arranged on the frequency axis to form 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 may be arranged on the frequency axis, respectively. Similarly, for RU types of 242-tone RU and 484-tone RU, 4 and 2 DRUs may be arranged on the frequency axis, respectively.

On the other hand, the arrangement of the subcarriers that make up a DRU on the frequency axis may differ from the arrangement of the subcarriers that make up 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, the subcarriers to which carrier indices are assigned in a DRU are data subcarriers and pilot subcarriers. In this case, for each RU type, the number of subcarriers that make up 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. FIG. 5 shows an example of a 106-tone RU corresponding to a PPDU with an 80 MHz bandwidth. The DRU subcarrier index shown in FIG. 5 is an integer starting from 1 and assigned in increments of 1 from low to high frequencies. In this case, in OFDMA using a DRU, a value ranging from 1 to 848 may be assigned as the DRU subcarrier index to each subcarrier corresponding to a PPDU. As an example, in OFDMA using a CRU, subcarriers assigned subcarrier indices of -499 to -394 may be assigned DRU subcarrier indices of 1 to 106, respectively. Also, in OFDMA using a CRU, subcarriers assigned subcarrier indices of -365 to -260 may be assigned DRU subcarrier indices of 107 to 212, respectively. In OFDMA using a CRU, subcarrier indexes are also assigned to unused subcarriers, resulting in discontinuous subcarrier indexes between RUs. On the other hand, if DRU subcarrier indexes are assigned only to subcarriers transmitting data or pilot signals as described above, the DRU subcarrier indexes become continuous on the frequency axis. The correspondence between DRU subcarrier indexes and CRU subcarrier indexes is not limited to the example shown in FIG. 5 . For example, an index for unused subcarriers may be assigned to the DRU subcarrier index. While FIG. 5 shows an example of a 106-tone RU, integer DRU subcarrier indexes starting from 1 may also be assigned to each subcarrier in the same manner 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 may be assigned consecutively in order, starting from the subcarrier with the lowest frequency. Similarly, for the bandwidths of 20 MHz, 40 MHz, 160 MHz, and 320 MHz, DRU subcarrier indices may be assigned to each RU type corresponding to each bandwidth.

The subcarriers that make up a DRU will now be described. First, an RU index can be assigned to each DRU. As with OFDMA using CRUs, the RU index can be assigned a range of values 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 80 MHz bandwidth, values in the ranges of 1 to 37, 1 to 16, and 1 to 8 can be assigned to each DRU as an RU index, respectively. Similarly, for 242-tone RUs and 484-tone RUs, values in the ranges of 1 to 4 and 1 to 2 can be assigned to each DRU as an RU index, respectively. Then, based on the DRU subcarrier index and RU index, each DRU can be configured with subcarriers that satisfy the following (Equation 1).

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 constitute one PPDU. For example, in the case of 26-tone RUs, 52-tone RUs, 106-tone RUs, 242-tone RUs, and 484-tone RUs, the number of RUs may be 37, 16, 8, 4, and 2, respectively.

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 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, since 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, since 100 mod 8 = 4. While Figure 6 shows an example of a PPDU with a bandwidth of 80 MHz, the frequency arrangement 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. Note that in actual OFDMA, multiple DRUs of different DRU types may be arranged on the frequency axis.

In the above example, an example was given in which the subcarriers constituting each DRU are distributed across the entire bandwidth occupied by the PPDU. That is, in the above example, the range on the frequency axis over which the subcarriers constituting each DRU are distributed may be equal to the bandwidth of the PPDU. On the other hand, 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 (predetermined bandwidth), the subcarriers constituting the DRU may be distributed across that predetermined bandwidth. In this case, one PPDU is divided into predetermined bandwidths on the frequency axis, and DRUs may be distributed and assigned using a DRU distribution pattern corresponding to each predetermined bandwidth. Here, distributing DRUs using a DRU distribution pattern corresponding to each predetermined bandwidth may mean, for example, distributing DRUs using the number of RUs of each DRU type corresponding to the predetermined bandwidth, DRU index, DRU subcarrier index, etc. For example, if the bandwidth of a PPDU is 160 MHz and the predetermined threshold is 80 MHz, the PPDU may be divided into two 80 MHz bandwidth regions on the frequency axis, and DRUs may be allocated to each region using a DRU allocation pattern corresponding to the 80 MHz bandwidth. Similarly, if the bandwidth of a PPDU is 320 MHz, the PPDU may be divided into four 80 MHz bandwidth regions on the frequency axis, and DRUs may be allocated to each region using a DRU allocation pattern corresponding to the 80 MHz bandwidth. In this way, the DRU allocation of 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, DRUs may be allocated using various combinations of different RU types included in the DRU allocation patterns, and the DRU allocation may differ for each band. In any case, the subcarriers that make up the DRU are more dispersed than the RU19 of the CRU's Middle-26 Tone. Therefore, by using a DRU, it is possible to distribute the power transmitted by a single STA to its surroundings on the frequency axis.

Figure 7 shows an example of DRU placement in a 160 MHz bandwidth PPDU using two DRU placement patterns corresponding to an 80 MHz bandwidth PPDU. The horizontal axis in Figure 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 frequency 80 MHz band using a DRU placement pattern corresponding to an 80 MHz bandwidth PPDU. Similarly, DRUs are allocated in the higher frequency 80 MHz band using a DRU placement pattern corresponding to an 80 MHz bandwidth PPDU. For example, the DRU arrangement using RU types from 26-tone RU to 484-tone RU in Figure 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 arranged can be 80 MHz. This bandwidth in which the subcarriers constituting one DRU are arranged can be called the distribution bandwidth. In other words, if n is the number of times a DRU arrangement pattern of a given bandwidth is repeated in the PPDU bandwidth (the number by which the PPDU bandwidth is divided), the distribution bandwidth can be 1/n of the PPDU bandwidth.

Here, the frequency bandwidth available for OFDMA using a DRU, i.e., the distribution bandwidth, may differ for each STA110. When communicating using OFDMA using a DRU, the subcarriers that make up the DRU may be distributed over a wide band. However, some STA110 may not be able to communicate using a wide band. For example, if STA110 only has a 40 MHz bandwidth available, it cannot communicate using OFDMA using a DRU in which subcarriers are distributed across an 80 MHz bandwidth. Therefore, AP101 may divide the PPDU bandwidth based on the distribution bandwidth of the DRU available to each STA110 participating in OFDMA, and allocate and position DRUs for each bandwidth. For example, suppose STA111 and STA112 are capable of performing OFDMA using a DRU with a distribution bandwidth of 40 MHz or less, and STA113 is capable of performing OFDMA using a DRU with a distribution bandwidth of 80 MHz or less. In this case, AP 101 may divide an 80 MHz bandwidth PPDU into two 40 MHz bands, a first band and a second band, on the frequency axis, and assign STA 111 and STA 112 to the first band and STA 113 to the second band. AP 101 may then assign RUs to STA 111 and STA 112 in the first band using a DRU configuration pattern corresponding to the 40 MHz bandwidth. AP 101 may also assign RUs to STA 113 in the second band using a DRU configuration pattern corresponding to the 40 MHz bandwidth. In this way, AP 101 may divide the PPDU on the frequency axis according to the distributed bandwidth available to each of STAs 110 participating in OFDMA using DRUs, and may allocate and assign DRUs to each of the divided bands. Alternatively, AP 101 may assign STA 111 and STA 112 to the first and second bands, respectively, and assign STA 113 to at least one of the bands. STA 111 and STA 112 may each be assigned a band equal to or less than the dispersion bandwidth. In this way, if there is a specific STA 110 whose available dispersion bandwidth is narrower than the bandwidth of the PPDU, AP 101 may segment the PPDU so that one or more specific bands equal to or less than the dispersion bandwidth are configured. For example, the bandwidth of the other bands resulting from the segmentation may be wider than the dispersion bandwidth. AP 101 may simply assign the specific STA 110 to that specific band, and may flexibly select the bands to which each of the other STAs is assigned. STA 110 may be assigned a DRU in each of the multiple bands resulting from the segmentation. For example, if a specific STA 110 is capable of performing OFDMA communications using DRUs in multiple bands, the AP 101 may allocate DRUs to that specific STA 110 in each band. This makes it possible to alleviate restrictions on the DRUs allocated to other STAs 110 when the distribution bandwidth of some STAs 110 is smaller than the PPDU bandwidth.

When dividing a single PPDU into multiple bandwidths and allocating DRUs using DRU allocation patterns corresponding to each bandwidth, RU indices may be assigned that are unique to the PPDU bandwidth. For example, if a 160 MHz bandwidth PPDU is divided on the frequency axis into two 80 MHz bandwidths and DRUs are allocated using 26-tone RUs in each band, RU indices of 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 STA110 whether the lower frequency band or the higher frequency band is being allocated when allocating a DRU to STA110 in PPDU communication. Furthermore, an index indicating the position of the band on the frequency axis may be provided for each bandwidth that is the unit of repetition of the DRU allocation pattern (the unit into which the PPDU is divided). For example, the PPDU band may be divided by the bandwidth that is the unit of repetition (the unit into which the PPDU is divided), and an index may be assigned to each band in order from lowest to highest frequency. Such an index may be called a band index. For example, if repetition is performed (the PPDU is divided) in units of 80 MHz bandwidth, it may be called an 80 MHz band index. In this case, the DRU assigned to the STA 110 may be uniquely identified by the combination of the band index, RU type, and RU index. Figure 7 shows an example in which an index value of 1 is assigned to the lower frequency and 2 is assigned to the higher frequency. In this case, the same RU index may be used between each band.

Note that, although the above description was given assuming that the number of subcarriers constituting a DRU and the number of subcarriers constituting a CRU are the same, the number of subcarriers constituting a DRU may be different from the number of subcarriers constituting a 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 a DRU on the frequency axis may be different from that described above. For example, a CRU may be composed of multiple subcarriers arranged so that they are contiguous on the frequency axis, and a 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 allocated for each band, allocation using CRUs may be performed in some bands and allocation using DRUs in other bands. Since the CRU and DRU are used independently for allocation in each band, there is no possibility of interference occurring between the CRU and DRU.

(Example of OFDMA communication using DRU)
An example of communication using OFDMA using a DRU will be described. FIG. 8 shows an example of a sequence between communication devices when OFDMA using 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 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 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, and may determine not to cause transmission if data is not available. For example, the AP 101 may transmit a Buffer Status Report Polling (BSRP) to acquire the amount of transmission data accumulated by each STA 110 (F801). When the STA 110 receives the BSRP, the STA 110 may report the amount of data accumulated to the AP 101. For example, the STA 110 may report by each transmitting a Buffer Status Report (BSR) (F802). Note that the AP 101 may use other methods to acquire the amount of data accumulated by each STA 110, or may use other methods to determine whether or not to cause each STA 110 to transmit.

The AP 101 may determine the amount of resources to allocate to each STA 110 based on the acquired amount of data stored by each STA 110. 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 stored by each STA 110 is proportional to the ratio of the number of subcarriers allocated to each STA 110. The AP 101 may then allocate RUs based on the amount of resources decided to be allocated to each STA 110. For example, the AP 101 may allocate an RU type with a large number of constituent subcarriers to a STA 110 that has accumulated a large amount of data. The AP 101 may also allocate multiple RUs to a STA 110 that has accumulated a large amount of data.

AP101 may use only the DRU to make allocations to each STA, or may use the DRU to make allocations to some STA110 and the CRU to make allocations to other STA110. For example, AP101 may select whether to use a DRU or a CRU based on the capability information of each STA110. For example, AP101 may use the DRU to make allocations to STA110 that are capable of performing OFDMA communication using the DRU. AP101 may also use the CRU to make allocations to STA110 that are not capable of performing OFDMA communication using the DRU. This makes it possible to select an appropriate allocation method depending on the capabilities of STA110. AP101 may also select whether to use a DRU or a CRU based on the distance from STA110 and the amount of radio wave attenuation. For example, the AP 101 may use a CRU to assign signals to STAs 110 located near the AP 101, and a DRU to assign signals to STAs 110 located far from the AP 101. This allows STAs 110 with large radio wave attenuation to transmit using higher transmission power. Furthermore, if the AP 101 experiences large radio wave attenuation between some of the STAs 110 that transmit in parallel, the AP 101 may use a DRU between all STAs. The AP 101 may determine that radio wave attenuation is large when the RSSI of the signal received from each STA 110 is below a threshold. RSSI may be an abbreviation for Received Signal Strength Indicator. When AP 101 performs DRU-based allocation to some STAs 110 and CRU-based allocation to other STAs 110, it may divide the PPDU on the frequency axis and perform DRU-based allocation and CRU-based allocation for each band. For example, when AP 101 performs UL MU OFDMA using a PPDU with a bandwidth of 160 MHz, it may use the lower frequency band of 80 MHz for CRU-based OFDMA and the higher frequency band of 80 MHz for DRU-based OFDMA. As an example, suppose AP 101 uses DRU-based OFDMA with STAs 111 and 112 and CRU-based OFDMA with STA 113. In this case, AP 101 may assign RU1, a 484-tone RU in FIG. 6, to STA 111, and RU2, a 484-tone RU, to STA 112. AP 101 may also assign RU1 to RU5, a 26-tone RU in FIG. 6, to STA 111, and RU14 to RU15, a 52-tone RU, to STA 112. On the other hand, AP 101 may assign RU1, a 996-tone RU in FIG. 3, to STA 113. AP 101 may also assign RU1 to RU5, a 26-tone RU in FIG. 3, to STA 113.

The AP 101 may also divide the PPDU on the frequency axis based on the distribution bandwidth available to each STA 110. For example, if there is a STA 110 participating in OFDMA that can only use a distribution bandwidth smaller than the bandwidth of the PPDU being used, the AP 101 may divide the PPDU based on this distribution bandwidth. Furthermore, if multiple STAs 110 have distribution bandwidth settings, the AP 101 may divide the PPDU based on the smallest distribution bandwidth among them. In this case, DRUs may be arranged and allocated in each divided band using a DRU configuration pattern corresponding to the bandwidth of that band. The AP 101 may also use a CRU to allocate to all STAs 110. For example, if there are a large number of STAs that cannot use a DRU among the STAs 110 that are transmitting in parallel, the AP 101 may use a CRU with all STAs.

AP101 notifies STA110 of information that can identify the RU assigned to each STA110 (RU assignment information). For example, AP101 may transmit a Basic Trigger frame containing RU assignment information to each STA110 (F803). These Trigger frames are MAC (Medium Access Control) frames transmitted using PPDUs such as UHR PPDU and EHT PPDU. By using the Basic Trigger frame, AP101 can notify each STA110 of RU assignment information and instruct each STA110 to transmit data. For example, AP 101 may notify RU allocation information such as the band to be allocated, the bandwidth to be allocated, whether the allocation is for a CRU or DRU, the RU type, and the RU index. If multiple RUs are allocated to STA 110, allocation information for each RU may be notified. STA 111 to STA 113 may transmit data based on the RU allocation information contained in the received Basic Trigger frame (F804). For example, if STA 110 receives information indicating that the RU allocated to itself is a CRU or DRU allocation, as well as the RU type and RU index to be used, it may identify the subcarriers to be used for transmission based on a correspondence table such as FIG. 3 or FIG. 6. The information indicating a CRU or DRU allocation may also be information indicating whether the allocation is for a DRU. Furthermore, when a PPDU is divided on the frequency axis to arrange and allocate RUs, the STA 110 may be notified that a CRU or DRU has been allocated, as well as the RU type and RU index to be used, and information that can identify the band and bandwidth to which the RU is allocated. Note that if the RU index is allocated so that it can uniquely identify the RU across the entire PPDU band, information identifying the band need not be notified. Each STA 110 may transmit data using a subcarrier identified based on the RU allocation information. This embodiment assumes that the frame transmitted from each STA 110 using the subcarrier corresponding to the DRU is a UHR TB (Trigger Based) PPDU. Each STA 110 then includes a data frame in the UHR TB PPDU. Specifically, it is assumed that the payload portion of the UHR TB PPDU includes an A-MPDU, to which one or more data-type MAC frames are concatenated. More specifically, it is assumed that the frame contains a QoS data type MAC frame 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 management frames and control frames may also be included in the A-MPDU of the UHR TB PPDU transmitted by the STA using the DRU. When the AP 101 receives data from each STA 110 via its respective subcarrier, it acknowledges the data (F805). For example, the AP 101 can acknowledge the data collectively to STA 111 through STA 113 by transmitting a Multi-STA Block Ack.

(Device configuration example)
9 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 901, a control unit 902, a function unit 903, an input unit 904, an output unit 905, a communication unit 906, and an antenna 907. The communication device 100 may include multiple antennas.

The storage unit 901 is composed of one or more memories, including ROM, RAM, etc., and may store various information such as control programs for the various operations of each functional unit constituting the communication device 100, 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 901 may also be composed of storage media such as flexible disks, hard disks, optical disks, magneto-optical disks, CD-ROMs, CD-Rs, magnetic tapes, non-volatile memory cards, and DVDs.

The control unit 902 is configured with one or more processors including, for example, a CPU or MPU, and controls the entire communication device 100 by executing a control program stored in the storage unit 901. The control unit 902 may also control the entire communication device 100 in cooperation with the control program stored in the storage unit 901 and the OS (Operating System). The terms CPU and MPU stand for Central Processing Unit and Micro Processing Unit, respectively. If the control unit 902 has multiple processors that can be implemented using multi-cores, for example, the entire communication device 100 may be configured to be controlled by the multiple processors.

The control unit 902 also controls the functional unit 903 to perform predetermined processes such as communication, image capture, printing, and projection. The functional unit 903 is hardware that enables the communication device 100 to perform the predetermined processes described above. For example, if the device is a camera, the functional unit 903 is an image capture unit that performs image capture processing. For example, if the device is a printer, the functional unit 903 is a print unit that performs print processing. For example, if the device is a projector, the functional unit 903 is a projection unit that performs projection processing.

The input unit 904 accepts various operations from the user. The output unit 905 outputs various types of information to the user via a monitor screen or speaker. Here, the output from the output unit 905 may be a display on the monitor screen, audio output from a speaker, vibration output, etc. The input unit 904 and output unit 905 may both be implemented as a single module, such as a touch panel. The input unit 904 and output unit 905 may each be a device integrated with the communication device 100, or may be a separate device.

The communication unit 906 controls wireless communications compliant with the IEEE 802.11bn standard. Furthermore, the communication unit 906 may control wireless communications compliant with other IEEE 802.11 standard series, such as legacy standards, in addition to the IEEE 802.11bn standard. The communication unit 906 controls the antenna 907 to send and receive signals for wireless communications generated by the control unit 902. The communication unit 906 is a so-called wireless chip, and may itself be equipped with one or more processors and memories. Note that if the communication device 100 supports other wireless communication standards, such as the NFC standard or the Bluetooth standard, or wired communications such as a wired LAN, in addition to the IEEE 802.11bn standard, the communication unit 906 may control communications compliant with these communication standards. Furthermore, if the communication device 100 is capable of performing wireless communications compliant with multiple communication standards, the communication device 100 may be configured to have separate communication units and antennas corresponding to each communication standard. Communication device 100 communicates data with the other communication device via communication unit 906. Note that antenna 907 may be configured as a separate unit from communication unit 906, or may be configured together with communication unit 906 as a single module.

Antenna 907 is an antenna capable of communication in, for example, the 2.4 GHz band, 5 GHz band, 6 GHz band, millimeter waves, etc. While FIG. 9 shows communication device 100 having two antennas 907, communication device 100 may have one or three or more antennas, or 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 906 for each antenna.

(Example of functional configuration)
The functional configuration of the communication device 100 (AP 101 and STA 110) in this embodiment will be described. FIG. 10 shows an example of a block diagram of the communication device 100 that receives capability information. FIG. 11 shows an example of a block diagram of the communication device 100 that transmits capability information. These functions can be realized, for example, by the control unit 902 executing a program stored in the storage unit 901, or by a processing function unit in the communication unit 906. Note that FIGS. 10 and 11 are diagrams explaining the main functions of this embodiment, and other functions are omitted. Therefore, for example, a control function for establishing a connection and communication between a normal AP and a STA, as well as functions generally possessed by a communication device, can naturally be possessed. Furthermore, multiple functional blocks in FIGS. 10 and 11 may be integrated into a single functional block, or a single functional block may be divided into multiple functional blocks.

Figure 10 shows an example configuration of a communication device 100 that receives capability information. The communication device 100 may be configured to include a frame control unit 1001, an information receiving unit 1002, and a wireless communication control unit 1003. The frame control unit 1001 generates and analyzes signals (frames) when communicating with a partner communication device. The frame control unit 1001 generates, for example, management frames for the communication device 100 to execute connection procedures. Management frames include Beacon, Probe Request, Probe Response, Association Request, and Association Response. The management frames generated by the frame control unit 1001 are not limited to these and may include, for example, Authentication frames and Action frames. The frame control unit 1001 may also generate control frames, data frames, etc. The frame control unit 1001 can receive management frames that include a UHR Capabilities element and the like defined in the IEEE 802.11 standard series. The frame control unit 1001 can request a frame that includes a UHR Capabilities element and the like from the other communication device. The frame control unit 1001 can also acquire the UHR Capabilities element and the like by analyzing a frame received from the other communication device. The frame control unit 1001 can notify the information receiving unit 1002 of the UHR Capabilities element and the like.

The information receiving unit 1002 acquires capability information of the other communication device based on information contained in the frame received by the frame control unit 1001. For example, a UHR Capabilities element or the like may include capability information indicating whether the other communication device is capable of performing OFDMA communication using a DRU. Furthermore, a UHR Capabilities element or the like may include information indicating the RU type and distribution bandwidth that the other communication device can use in OFDMA communication using a DRU. The capability information may indicate, for example, that the other communication device is capable of performing operations for OFDMA communication using a DRU. Furthermore, the capability information may include either transmission capabilities or reception capabilities, or both. The information receiving unit 1002 may notify the wireless communication control unit 1003 of the acquired capability information.

The wireless communication control unit 1003 performs transmission processing for each frame generated by the frame control unit 1001. The wireless communication control unit 1003 also notifies the frame control unit 1001 of frames received via antenna 907. The wireless communication control unit 1003 performs frame transmission and reception processing based on capability information of the other communication device. For example, if the other communication device is capable of communication using OFDMA with a DRU, the wireless communication control unit 1003 may transmit or receive data frames (data) using OFDMA with a DRU or CRU. Also, if the other communication device is capable of communication using OFDMA with a CRU, the wireless communication control unit 1003 may transmit or receive data frames (data) using OFDMA with a CRU. The RU type and distribution bandwidth of the DRU used by the wireless communication control unit 1003 in communication using OFDMA with a DRU may be determined based on the capability information of the other communication device contained in the UHR Capabilities element acquired from the other communication device.

Figure 11 shows an example configuration of a communication device 100 that transmits capability information. The communication device 100 may be configured to include a frame control unit 1101, an information transmission unit 1102, and a wireless communication control unit 1103. The frame control unit 1101 operates in the same manner as the frame control unit 1001. The frame control unit 1101 may transmit a management frame including a UHR Capabilities element, etc., specified in the IEEE 802.11 standard series. The information transmission unit 1102 transmits capability information of the communication device of the own device to the other communication device via the frame control unit 1101. For example, the information transmission unit 1102 may transmit a frame including a UHR Capabilities element, etc., including capability information indicating whether the own device is capable of performing OFDMA communication using a DRU, to the other communication device via the frame control unit. Furthermore, the information transmitting unit 1102 may transmit a frame including a UHR Capabilities element, which includes information indicating the RU type and distribution bandwidth that the device itself can use in OFDMA communications using a DRU, to the other communication device via the frame control unit. The information transmitting unit 1102 may also notify the wireless communication control unit 1103 that it has transmitted its own device's capability information to the other communication device. The wireless communication control unit 1103 may operate in the same manner as the wireless communication control unit 1003. The wireless communication control unit 1103 may perform frame transmission and reception processing based on the capability information notified by the device itself to the other communication device. For example, if the wireless communication control unit 1103 notifies that the device itself can communicate using OFDMA using a DRU, it may transmit or receive a data frame (data) using OFDMA using a DRU or CRU. Furthermore, if the wireless communication control unit 1103 notifies that its own device can communicate using OFDMA with a CRU, it can transmit or receive data frames (data) using OFDMA with a CRU. The RU type and distribution bandwidth of the DRU used by the wireless communication control unit 1103 in communication using OFDMA with a DRU can be determined based on the capability information notified to the other communication device.

(Processing flow)
A connection process between communication devices in this embodiment will be described. FIG. 12 shows an example of a sequence of messages exchanged between the AP 101 and the STA 110. The AP 101 executes connection processes between each of the STAs 111 to 113. The AP 101 periodically broadcasts information such as a network identifier (BSSID) required for other communication devices such as the STA 110 to connect to the AP 101 (F1201). For example, the AP 101 may broadcast using a beacon frame. When the STA 110 detects the AP 101 by receiving the beacon frame, it initiates a wireless connection procedure. Note that the timing at which the STA 110 initiates the wireless connection procedure is not limited to this. For example, if the AP 101 does not transmit a beacon frame or if the STA 110 does not properly receive a beacon frame transmitted by the AP 101, the STA 110 may initiate the wireless connection procedure without receiving the beacon frame. For example, the STA 110 may start a wireless connection procedure using a service set identifier (SSID) registered in advance by a user or the like. The STA 110 may start the wireless connection procedure by transmitting a probe request frame (F1202). Upon receiving the probe request frame, the AP 101 transmits a probe response frame addressed to the STA 110 (F1203). Upon receiving the probe response, the STA 110 transmits an authentication frame to the AP 101 (F1204). Upon receiving the authentication frame, the AP 101 transmits the authentication frame to the STA 110 (F1205). Upon receiving the Authentication frame, the STA 110 transmits an Association Request frame to the AP (F1206). Upon receiving the Association Request frame, the AP 101 transmits an Association Response frame to the STA 110 (F1207). In this manner, a connection procedure is performed between the AP 101 and the STA 110, thereby establishing a link between the AP 101 and the STA 110 using a wireless medium. After the connection procedure, the AP 101 and the STA 110 may perform a 4-way handshake or the like to exchange security information. The AP 101 and the STA 110 may also perform the connection process using a method other than the above. The AP 101 and the STA 110 transmit and receive data using the link established by the connection process (F1208). For example, the AP 101 and the STA 110 may communicate data using UL MU OFDMA using the communication procedure shown in FIG.

In the above-mentioned connection process, AP101 and STA110 may share information regarding the capabilities available for communication with the other communication device. For example, AP101 and STA110 may notify the other communication device that they are capable of communication using OFDMA, and may acquire from the other communication device that the other communication device is capable of communication using OFDMA. AP101 and STA110 may also notify the other communication device that they are capable of OFDMA communication using a DRU, and may acquire from the other communication device that the other communication device is capable of OFDMA communication using a DRU. AP101 and STA110 may also notify the other communication device that they are capable of OFDMA communication using a CRU, and may acquire from the other communication device that the other communication device is capable of OFDMA communication using a CRU. Such information indicating whether or not communication device 100 has the capabilities available for communication may be referred to as capability information. The capability information is not limited to the above. For example, the capability information may include information such as the RU type that the communication device 100 can use in communication using OFDMA, the available distribution bandwidth, and the number of available RUs. Furthermore, if the communication device 100 is capable of performing OFDMA using DRUs only for transmission, the communication device 100 may report, as capability information, that it is capable of performing OFDMA transmission using DRUs. Furthermore, if the communication device 100 is capable of performing only OFDMA reception using DRUs, the communication device 100 may report, as capability information, that it is capable of performing OFDMA reception using DRUs. Note that the communication device 100 may autonomously report its capability information. Furthermore, the communication device 100 may report its capability information based on a request from the other communication device.

AP101 may periodically notify its own device's capability information. For example, AP101 may include its own device's capability information in the Beacon frame it broadcasts in F1201. With this configuration, STA110 can recognize that AP101 is capable of performing OFDMA communication using DRU before starting the connection procedure. This allows STA110 to reduce the amount of information exchanged during the connection procedure. STA110 can also perform control to preferentially connect to AP101 that can perform OFDMA communication using DRU. Furthermore, AP101 can notify an unspecified number of STA110 of its capability information, enabling efficient use of wireless resources. AP101 may also notify its own device's capability information using a FILS Discovery frame. FILS Discovery frames can be used to broadcast part of the information included in Beacon frames. For example, SSID, channel information, etc. can be reported using a FILS Discovery frame. FILS is an abbreviation for Fast Initial Link Setup. Using a FILS Discovery frame instead of a Beacon frame enables efficient use of wireless resources. AP 101 can also notify its own device's capability information using a Probe Response frame (F1203) or an Association Response frame (F1207). STA 110 can obtain the capability information of AP 101 by receiving these frames. AP 101 can also request STA 110 to notify its capability information using a frame used in the connection process. For example, AP101 may request STA110 to notify it of its capability information using a Probe Response frame (F1203) or an Association Response frame (F1207).

STA110 may notify AP101 of its capability information using a frame used in the connection process. For example, STA110 may notify AP101 of its capability information using a Probe Request frame (F1202) or an Association Request frame (F1206). By receiving these frames, AP101 becomes able to obtain STA110's capability information. STA110 may request AP101 to notify it of its capability information using a frame used in the connection process. For example, STA110 may request AP101 to notify it of its capability information using a Probe Request frame (F1202) or an Association Request frame (F1206).

(Example of a format for notifying capability information)
The communication device 100 may notify capability information using an information element (IE) indicating capabilities related to the IEEE 802.11bn standard, which was added in the IEEE 802.11bn standard. The IE may also be referred to as an information element. For example, the IE indicating capabilities related to the IEEE 802.11bn standard may be an IE called a UHR Capabilities element. The UHR Capabilities element may be included in a beacon frame, a probe request frame, a probe response frame, or an association request frame. The UHR Capabilities element may also be included in an association request frame, an association response frame, or the like. The UHR Capabilities element may be included in frames other than these. Fig. 13 shows an example of the configuration of a UHR Capabilities element. The UHR Capabilities element includes an Element ID field 1301, a Length field 1302, and an Extended Element ID field 1303. The UHR Capabilities element may include a UHR MAC Capabilities Information field 1304 and a UHR PHY Capabilities Information field 1305. The type of element is indicated by a combination of the Element ID field 1301 and the Extended Element ID field 1303. For example, if the Element ID field 1301 is set to 255 and the Extended Element ID field 1303 is set to 138, this element may be indicated as a UHR Capabilities element. The Length field 1302 indicates the length of this element. The UHR MAC Capabilities Information field 1304 indicates the Media Access Control (MAC) capabilities of the communication device. The UHR PHY Capabilities Information field 1305 indicates the PHY capabilities of the communication device.

The UHR PHY Capabilities Information field 1305 includes a DRU Support field 1311. The UHR PHY Capabilities Information field 1305 includes a Supported DRU Type field 1312. The UHR PHY Capabilities Information field 1305 includes a Supported DRU Distributed Band Width field 1313. The DRU Support field 1311 indicates whether the communication device can perform OFDMA communication using a DRU. For example, the DRU Support field 1311 may be a 1-bit field. When the DRU Support field 1311 is set to a value of 1, it indicates that OFDMA communication using a DRU is possible, and when it is set to a value of 0, it indicates that OFDMA communication using a DRU is not possible. Note that the DRU Support field 1311 may be provided as a separate field from fields and subfields that indicate information regarding whether OFDMA communication is possible or not and information related to OFDMA communication using a CRU. This makes it possible to independently notify whether the communication device is capable of performing functions related to OFDMA using a CRU and whether it is capable of performing OFDMA using a DRU.

The Supported DRU Type field 1312 indicates the RU type that the communication device can use in OFDMA communication using the DRU. For example, the Supported DRU Type field 1312 may be a 3-bit field. As an example, a 26-tone RU, a 52-tone RU, and a 106-tone RU will be referred to as the first RU type, the second RU type, and the third RU type, respectively. Also, a 242-tone RU, a 484-tone RU, and a 996-tone RU will be referred to as the fourth RU type, the fifth RU type, and the sixth RU type, respectively. The Supported DRU Type field 1312 may indicate the RU type that the communication device can use in decimal or binary notation. For example, when the Supported DRU Type field 1312 is set to a value of 0, it may indicate that the communication device is capable of using the first RU type. When the Supported DRU Type field 1312 is set to a value of 1, it may indicate that the communication device is capable of using the first RU type and the second RU type. When the Supported DRU Type field 1312 is set to a value of 2, it may indicate that the communication device is capable of using the first to third RU types. When the Supported DRU Type field 1312 is set to a value of 3, it may indicate that the communication device is capable of using the first to fourth RU types. When the value 4 is set in the Supported DRU Type field 1312, it may indicate that the communications device can use the first to fifth RU types. When the value 5 is set in the Supported DRU Type field 1312, it may indicate that the communications device can use the first to sixth RU types. When a value other than the above is set in the Supported DRU Type field 1312, it may indicate that an RU consisting of more subcarriers than the sixth RU type can be used. Furthermore, the Supported DRU Type field 1312 may set values other than the above as reserved. Note that the correspondence between each of the decimal or binary representation values and the RU types that the communications device can use is not limited to the above.

Furthermore, the Supported DRU Type field 1312 may indicate the RU types that the communications device can use using a bitmap representation. For example, the Supported DRU Type field 1312 may be a field consisting of five bits, with each bit corresponding to a respective RU type. For example, the first to fifth bits may correspond to the first to fifth RU types, respectively. For example, if the Nth bit is set to a value of 1, this may indicate that the communications device can use the Nth RU type. Furthermore, if the Nth bit is set to a value of 0, this may indicate that the communications device cannot use the Nth RU type. Furthermore, the Supported DRU Type field 1312 may have a sixth bit, which may correspond to the sixth RU type.

The Supported DRU Distributed Band Width field 1313 indicates the distributed bandwidth of the DRU that the communication device can use in OFDMA communication using the DRU. For example, the Supported DRU Distributed Band Width field 1313 may be a 3-bit field. The Supported DRU Distributed Band Width field 1313 may indicate the distributed bandwidth of the DRU that the communication device can use in decimal or binary representation. For example, the Supported DRU Distributed Band Width field 1313 may indicate that the communication device can use a DRU with a distribution bandwidth of 20 MHz when set to a value of 0. For example, the Supported DRU Distributed Band Width field 1313 may indicate that the communication device can use a DRU with a distribution bandwidth of 20 to 40 MHz when set to a value of 1. For example, the Supported DRU Distributed Band Width field 1313 may indicate that the communication device can use a DRU with a distribution bandwidth of 20 to 80 MHz when set to a value of 2. For example, when the Supported DRU Distributed Band Width field 1313 is set to a value of 3, it may indicate that the communication device can use a DRU with a distribution bandwidth of 20 to 160 MHz. For example, when the Supported DRU Distributed Band Width field 1313 is set to a value of 4, it may indicate that the communication device can use a DRU with a distribution bandwidth of 20 to 320 MHz. For example, when the Supported DRU Distributed Band Width field 1313 is set to a value other than the above, it may indicate that the communication device can use a DRU with a distribution bandwidth other than the above. As an example, when the Supported DRU Distributed Band Width field 1313 is set to a value of 5 or 6, it may indicate that the communication device can use a DRU with a wider distribution bandwidth than the above. As an example, when the Supported DRU Distributed Band Width field 1313 is set to a value of 5 or 6, it may indicate that the communication device can use a DRU with a narrower distribution bandwidth than the above. Furthermore, the Supported DRU Distributed Band Width field 1313 may reserve values other than the above.

Furthermore, the Supported DRU Distributed Band Width field 1313 may indicate the distribution bandwidth available to the communication device using a bitmap representation. For example, the Supported DRU Distributed Band Width field 1313 may be a field consisting of five bits, with each bit corresponding to a respective distribution bandwidth. As an example, the distribution bandwidths of 20 MHz, 40 MHz, 80 MHz, 160 MHz, and 320 MHz may be referred to as the first to fifth distribution bandwidths, respectively. In this case, the first to fifth bits of the Supported DRU Distributed Band Width field 1313 may be associated with the first to fifth distribution bandwidths, respectively. For example, if the Nth bit is set to a value of 1, it may indicate that the communication device is capable of using the Nth distribution bandwidth. Also, if the Nth bit is set to a value of 0, it may indicate that the communication device is not capable of using the Nth distribution bandwidth.

Note that the DRU Support field 1311, Supported DRU Type field 1312, and Supported DRU Distributed Band Width field 1313 may be configured as a single field. For example, an integrated field formed by integrating these three fields may indicate, in decimal or binary notation, whether the communication device is capable of performing OFDMA communication using a DRU, the available RU types, and the available distributed bandwidth. As an example, when the integrated field is set to a value of 0, it may indicate that the communication device is unable to perform OFDMA communication using a DRU. Furthermore, when the integrated field is set to a value of 1, it may indicate that the communication device is capable of performing OFDMA communication using a DRU and is able to use the first RU type and the first distributed bandwidth. When the value of the integration field is set to 2, it may indicate that the communication device is capable of performing OFDMA communication using a DRU and is capable of using a first RU type and first to second distributed bandwidths. The integration field may be composed of only a portion of the DRU Support field 1311, the Supported DRU Type field 1312, and the Supported DRU Distributed Band Width field 1313. For example, the integration field may be composed of the Supported DRU Type field 1312 and the Supported DRU Distributed Band Width field 1313. In this case, if the DRU Support field 1311 indicates that the communication device cannot perform OFDMA communication using a DRU, this integrated field may be omitted.

Note that the DRU Support field 1311, Supported DRU Type field 1312, and Supported DRU Distributed Band Width field 1313 may be included in other fields. For example, they may be included in the UHR MAC Capabilities Information field 1304 instead of the UHR PHY Capabilities Information field 1305. Furthermore, any of the fields may be included in another IE. For example, the Supported DRU Type field 1312 and the Supported DRU Distributed Band Width field 1313 may be included in the UHR Operation element. The capability information may be communicated using the Extended Capabilities field. In this case, the communication device 100 may exchange capability information with a communication device that does not comply with the IEEE 802.11bn standard but is capable of performing OFDMA communication using a DRU. Furthermore, new elements or fields may be provided for exchanging capability information related to OFDMA using a DRU between communication devices. The new elements and fields enable flexible exchange of information required for OFDMA communication using a DRU between communication devices. The capability information may also be included in the Action frame. In this case, after a link between devices has been established, it becomes possible to flexibly change the link settings. For example, it becomes possible to change the corresponding RU type or corresponding distributed bandwidth depending on the surrounding environment.

(Example of processing flow of communication device when connecting)
A processing flow of a communication device 100 capable of performing OFDMA communication using a DRU will be described. FIG. 14 shows an example of the processing flow of the communication device 100. This operation flow can be executed by the control unit 902 of the communication device 100 reading and executing a computer program stored in the storage unit 901 according to a connection procedure with a partner communication device. The operation of the AP 101 will be described below as an example, but the STA 110 can operate in a similar manner. First, the AP 101 establishes a wireless connection with the STA 110 (S1401). During the wireless connection process, the AP 101 can exchange capability information regarding OFDMA communication using a DRU with the STA 110. For example, if a frame received from the STA 110 contains capability information indicating that OFDMA communication using a DRU is possible, the AP 101 can determine that the STA 110 is capable of performing OFDMA communication using a DRU. In this case, AP 101 stores, as an attribute of STA 110, that communication via OFDMA using a DRU is possible. On the other hand, if a UHR Capabilities element is not included in a frame received from STA 110 during wireless connection processing, AP 101 may determine that STA 110 is not capable of communication via OFDMA using a DRU. Furthermore, if capability information indicating that communication via OFDMA using a DRU is not possible is included in a frame received from STA 110, AP 101 may determine that STA 110 is not capable of communication via OFDMA using a DRU. In these cases, AP 101 stores, as an attribute of STA 110, that communication via OFDMA using a DRU is not possible. Furthermore, AP 101 may exchange communication parameters that can be used when performing communication via OFDMA using a DRU with STA 110. For example, the RU type and distribution bandwidth that the STA 110 can use can be exchanged as communication parameters.

Once a connection is established between AP101 and STA110, AP101 performs data communication (S1402). For example, AP101 may select a communication method for performing data communication based on the capability information of STA110 exchanged during the connection process. For example, AP101 may select a communication method for performing data communication from among a communication method using OFDMA with a DRU, a communication method using OFDMA with a CRU, and a communication method without OFDMA. If STA110 is capable of performing communication using OFDMA with a DRU, AP101 may assign RUs based on communication parameters that STA110 can use. For example, AP101 may assign RUs using the RU type, distribution bandwidth, and number of RUs that STA110 can use. As an example, if the dispersion bandwidth available to the STAs 110 is smaller than the bandwidth of the PPDU, the AP 101 may divide the PPDU on the frequency axis to form a band with a bandwidth equal to or smaller than the dispersion bandwidth available to the STAs 110. The AP 101 may then allocate RUs to the STAs 110 in that band. On the other hand, if the STAs 110 can use multiple RUs, the AP 101 may allocate RUs to the STAs 110 in each of the divided bands. The AP 101 may make allocations using the RU types available to each STA 110. When data for each STA 110 accumulates in its own transmission queue, the AP 101 may transmit data to each STA 110 in parallel using OFDMA with DRUs. The AP 101 may also acquire the data accumulation status of each STA 110, and, based on that accumulation status, allocate RUs for each STA 110 to transmit, causing the STAs 110 to perform transmission. For example, AP101 may transmit a Trigger frame indicating the allocation of RUs to each STA110. In this case, AP101 may receive data transmitted from each STA110 via each RU after a predetermined time has elapsed since transmitting the Trigger frame. Furthermore, if the STA110 is capable of performing OFDMA communication using a CRU, AP101 may communicate data using OFDMA using a CRU. If the STA110 is not capable of performing OFDMA communication, AP101 may communicate data without using OFDMA. AP101 may repeatedly execute S1402 until wireless LAN communication is disabled, for example, by a user instruction (S1403).

As described above, according to this embodiment, a communication device acquires predetermined capability information from a counterpart communication device indicating whether the counterpart communication device has a predetermined capability for performing OFDMA using a DRU, and performs OFDMA communication based on the counterpart communication device's capability information. Alternatively, the communication device performs OFDMA communication based on notifying the counterpart communication device that the counterpart communication device has a predetermined capability for performing OFDMA using a DRU. With this configuration, the communication device can select an appropriate communication method based on the counterpart communication device's capability information, even in an environment where a first communication method using OFDMA using a CRU and a second communication method using OFDMA using a DRU are mixed. This enables OFDMA to be performed with high transmission power using a DRU, even when using frequencies in the 6 GHz band, thereby enabling communication over a wider range and improving communication stability. Furthermore, if the counterpart communication device is capable of performing OFDMA communication using a DRU, the communication device exchanges usable RU types and distribution bandwidths with the counterpart communication device. With this configuration, even if the STA 110 cannot use a DRU in which subcarriers are arranged across a wide band, it can appropriately divide the PPDU on the frequency axis, arrange the RUs, and communicate. This enables OFDMA communication using DRUs to be performed with a larger number of communication devices. In this embodiment, a DRU is described as an RU configured with multiple subcarriers arranged such that at least some of the subcarriers are discontinuous on the frequency axis. Furthermore, a CRU is described as an RU configured with multiple subcarriers arranged so that they are contiguous on the frequency axis. These may be referred to by other names. Although an example of an element using a UHR Capabilities element or the like has been shown as an example of an element for a communication device to notify capability information, these elements and the fields included in these elements may be referred to by other names. Furthermore, while examples showing the relationships between bandwidth, RU type, RU index, subcarrier index, etc. have been described in Figures 3 and 6, these are merely examples, and OFDMA using DRUs and CRUs with different configurations may also be performed.
(Other Examples)
The present invention can also be realized by supplying a program that realizes one or more of the 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.The present invention can also be realized by a circuit (e.g., an ASIC) that realizes one or more of the functions.

The invention is not limited to the above-described embodiments, and various modifications and variations are possible without departing from the spirit and scope of the invention. Therefore, the following claims are appended to clarify the scope of the invention.

This application claims priority from Japanese Patent Application No. 2024-076092, filed May 8, 2024, the entire contents of which are incorporated herein by reference.

Claims (13)

A communication device that performs communication in accordance with the IEEE 802.11 standard series with another communication device,
a communication means capable of performing communication using a plurality of communication methods, including: a first communication method in which wireless resources are allocated using at least two or more first-type resource units (RUs) each consisting of a plurality of subcarriers arranged so as to be contiguous on a frequency axis, and data is communicated using the wireless resources by orthogonal frequency division multiple access (OFDMA); and a second communication method in which wireless resources are allocated using at least two or more second-type RUs each consisting of a plurality of subcarriers arranged so that at least some of the subcarriers are discontinuous on the frequency axis, and data is communicated using the wireless resources by OFDMA;
receiving means for receiving, from the other communication device, a predetermined wireless frame including predetermined capability information indicating whether the other communication device has a predetermined capability to perform communication using the second communication method;
When the communication means uses an OFDMA communication method in communication with another communication device,
If the other communication device has the predetermined capability, communicating with the other communication device using either the first communication method or the second communication method;
A communication device that communicates with the other communication device using the first communication method when the other communication device does not have the predetermined capability. A communication device that performs communication in accordance with the IEEE 802.11 standard series with another communication device,
a communication means capable of performing communication using a plurality of communication methods, including: a first communication method in which wireless resources are allocated using at least two or more first-type resource units (RUs) each consisting of a plurality of subcarriers arranged so as to be contiguous on a frequency axis, and data is communicated using the wireless resources by orthogonal frequency division multiple access (OFDMA); and a second communication method in which wireless resources are allocated using at least two or more second-type RUs each consisting of a plurality of subcarriers arranged so that at least some of the subcarriers are discontinuous on the frequency axis, and data is communicated using the wireless resources by OFDMA;
a transmitting means for transmitting to the other communication device a predetermined wireless frame including predetermined capability information indicating whether the communication device has a predetermined capability to perform communication using the second communication method,
When the communication means uses an OFDMA communication method in communication with another communication device,
when the predetermined capability information is transmitted to the other communication device, the communication device communicates with the other communication device using either the first communication method or the second communication method;
a communication device that, when the predetermined capability information has not been transmitted to the other communication device, communicates with the other communication device using the first communication method; The communication device according to claim 1 or 2, wherein the predetermined capability information includes information indicating the number of subcarriers of the second type RU that the other communication device can use in the second communication method. The communication device according to claim 1 , wherein the predetermined capability information includes information indicating a frequency bandwidth that the other communication device can use in the second communication method. The communication device according to claim 1 , wherein the predetermined wireless frame is a wireless frame conforming to the IEEE 802.11bn standard that includes an information element (IE) indicating a capability related to the IEEE 802.11bn standard and that is transmitted from the other communication device. The communication device according to claim 5 , wherein the IE is an Ultra High Reliability (UHR) Capabilities Element. The communication device according to claim 5 or 6, wherein the predetermined capability information is included in a UHR Physical layer (PHY) Capabilities Information field in the IE. The communication device according to claim 5 or 6, wherein the predetermined capability information is included in a UHR Media Access Control (MAC) Capabilities Information field in the IE. The communication device according to any one of claims 1 to 8, wherein the predetermined radio frame includes a field or subfield indicating the predetermined capability information that is different from a field or subfield including information indicating that the other communication device is capable of performing OFDMA communication. The communication device according to claim 1 , wherein the predetermined wireless frame is at least one of a beacon, a probe request, a probe response, an association request, an association response, and a FILS discovery frame. A communication method executed by a communication device that performs communication in accordance with the IEEE 802.11 standard series with another communication device, comprising:
performing communication using a plurality of communication methods, including 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 as to be contiguous 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 consisting of a plurality of subcarriers arranged so that at least some of the subcarriers are discontinuous on the frequency axis, and data is communicated using the radio resources by OFDMA;
receiving, from the other communication device, a predetermined radio frame including predetermined capability information indicating whether the other communication device has a predetermined capability to perform communication using the second communication method;
When an OFDMA communication method is used in communication with another communication device,
If the other communication device has the predetermined capability, communicating with the other communication device using either the first communication method or the second communication method;
a communication method for communicating with the other communication device using the first communication method when the other communication device does not have the predetermined capability. A communication method executed by a communication device that performs communication in accordance with the IEEE 802.11 standard series with another communication device, comprising:
performing communication using a plurality of communication methods including: 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 as to be contiguous 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 consisting of a plurality of subcarriers arranged so that at least some of the subcarriers are discontinuous on the frequency axis, and data is communicated using the radio resources by OFDMA;
transmitting to the other communication device a predetermined wireless frame including predetermined capability information indicating whether the communication device has a predetermined capability to perform communication using the second communication method;
When an OFDMA communication method is used in communication with another communication device,
when the predetermined capability information is transmitted to the other communication device, the communication device communicates with the other communication device using either the first communication method or the second communication method;
a communication method comprising: if the predetermined capability information has not been transmitted to the other communication device, communicating with the other communication device using the first communication method. A program for causing a computer to function as each of the means included in the communication device according to any one of claims 1 to 10.