Communication device, control method, and program

Abstract

A communication device capable of communicating with another communication device using a wireless frame conforming to the IEEE802.11 series of standards includes a second frequency band determined on the basis of a second bandwidth that can be supported by the other communication device and a third frequency band other than the second frequency band in a first frequency band having a first bandwidth used by the communication device for communication. When a frequency resource in the second frequency band is allocated to a device other than the other communication device in frequency division multiplex communication that is performed by the communication device with a plurality of devices including the other communication device, the communication device acquires, from the other communication device, capability information indicating whether or not the other communication device has a prescribed capability to perform frequency division multiplex communication by changing a frequency band to be used from the second frequency band to a fourth frequency band having the second bandwidth including part of the third frequency band, allocates the frequency resource to the other communication device to perform communication with the other communication device, allocates the frequency resource from within the second frequency band to the other communication device without changing the frequency band to be used by the other communication device on the basis of the fact that the other communication device does not have the prescribed capability, and allocates, to the other communication device, the frequency resource from within the second frequency band or from within the fourth frequency band by changing the frequency band to be used by the other communication device to the fourth frequency band on the basis of the fact that the other communication device has the prescribed capability.

Description

Communication Device, Control Method, and Program

[0001] The present disclosure relates to data communication technology in a communication device capable of communicating using a communication link composed of a plurality of channels.

[0002] In recent years, with the increase in the amount of data to be communicated, the development of communication technologies such as wireless LAN (Local Area Network) has been advanced. As the main communication standards of wireless LAN, the IEEE (Institute of Electrical and Electronic Engineers) 802.11 standard series is known. The IEEE 802.11 standard series includes IEEE 802.11a / b / g / n / ac / ax / be standards, etc. For further improvement of communication reliability, the development of the IEEE 802.11bn standard is in progress as a successor standard to the IEEE 802.11be standard. In the IEEE 802.11WG (Working Group) that formulates the IEEE 802.11bn standard, in the UHR SG, the goals and scope of study of this standard are determined, and in TGbn, the details of the technologies to be included in this standard are planned to be specified. Note that UHR SG is an abbreviation for Ultra High Reliability Study Group. Also, TGbn is an abbreviation for Task Group bn.

[0003] As one of the candidate technologies included in the IEEE 802.11bn standard, a technology for efficiently using frequency resources in a communication method using a communication link composed of a plurality of channels is being studied. For example, in Patent Document 1, a technology for communicating using other channels when the Primary Channel used to acquire the transmission right cannot be used is described.

[0004] U.S. Patent No. 11,696,353

[0005] The present disclosure provides a technology for efficiently using frequency resources in a communication system using a communication link composed of a plurality of channels.

[0006] A communication device according to one aspect of the present disclosure is a communication device capable of communicating with other communication devices using wireless frames compliant with the IEEE 802.11 standard series, wherein in the first frequency band of a first bandwidth used by the communication device for communication, there exists a second frequency band determined based on a second bandwidth that the other communication device can handle, and a third frequency band other than the second frequency band, and in frequency division multiplexing communication performed by the communication device with a plurality of devices including the other communication device, when the frequency resources of the second frequency band are allocated to a device other than the other communication device, the other communication device uses a fourth frequency band of the second bandwidth that includes the second frequency band and a part of the third frequency band. The system includes an acquisition means for acquiring capability information from the other communication device indicating whether or not it has the capability to perform the frequency division multiplexing communication by changing the number of frequency bands, and a communication means for allocating frequency resources to the other communication device and communicating with the other communication device, wherein the communication means allocates frequency resources from the second frequency band to the other communication device without changing the frequency band used by the other communication device, based on the fact that the other communication device does not have the predetermined capability, and allocates frequency resources to the other communication device from the second frequency band, or from the fourth frequency band by changing the frequency band used by the other communication device to the fourth frequency band, based on the fact that the other communication device has the predetermined capability.

[0007] According to this disclosure, frequency resources can be used efficiently in a communication system that uses a communication link composed of multiple channels.

[0008] Other features and advantages of this disclosure will become apparent from the following description with reference to the accompanying drawings. In the accompanying drawings, the same or similar components are given the same reference numeral.

[0009] The attached drawings are included in the specification and constitute part thereof, illustrating embodiments of the present disclosure and used together with the description to explain the principles of the present disclosure. Figure 1 is a diagram showing an example configuration of a wireless communication system. Figure 2 is a schematic diagram showing an example of a time chart when a communication device transmits data. Figure 3 is a schematic diagram showing an example of a time chart for communication using a DSO. Figure 4 is a diagram showing an example of the hardware configuration of a communication device. Figure 5 is a diagram showing an example of the functional configuration of an AP. Figure 6 is a diagram showing an example of the functional configuration of an STA. Figure 7 is a diagram showing an example of a sequence executed when a communication device establishes a connection. Figure 8 is a diagram showing an example of the configuration of a UHR Capabilities element. Figure 9 is a diagram showing an example of a time chart when downlink data communication is performed. Figure 10 is a diagram showing an example of a processing flow executed by an AP. Figure 11 is a diagram showing an example of a processing flow executed by an STA. Figure 12 is a diagram showing an example of a time chart when uplink data communication is performed. Figure 13 is a diagram showing an example of a processing flow executed by an AP. Figure 14 is a diagram showing an example of a processing flow executed by an STA. Figure 15 is a diagram showing an example of the configuration of a User Info field. Figure 16 shows an example of the mapping between the User Info field setting and the assigned RU. Figure 17 shows an example of the RU arrangement in OFDMA communication and the RU index associated with each RU.

[0010] The embodiments will be described in detail below with reference to the attached drawings. Note that the following embodiments do not limit the scope of the claims. While the embodiments describe multiple features, not all of these features are necessary, and the features may be combined in any way. Furthermore, in the attached drawings, identical or similar configurations are given the same reference numerals, and redundant descriptions are omitted.

[0011] (System Configuration) Figure 1 shows an example of the configuration of a wireless communication system according to this embodiment. The wireless communication system includes, for example, an access point (AP) 101 and stations (STA) 111 and STA 112. STA 111 and STA 112 are sometimes referred to as STA 110 without distinction. Also, AP 101 and STA 110 are sometimes referred to as communication device 100 without distinction. AP 101 and STA 110 are communication devices capable of performing wireless communication compliant with the IEEE 802.11 standard series. IEEE is an abbreviation for Institute of Electrical and Electronics Engineers. Figure 1 shows a configuration in which STA 111 and STA 112 participate in a network 121 constructed by AP 101. Network 121 may also be called a Basic Service Set (BSS). In the network 121 shown in Figure 1, a configuration with one AP 101 and two STA 110s is shown. However, for example, there may be multiple AP 101s, and there may be one or more STA 110s. In that case, each STA 110 may be connected to one AP 101, or one STA 110 may be connected to multiple AP 101s.

[0012] In this embodiment, the communication device 100 is configured to execute a communication method compliant with the IEEE 802.11bn standard. The IEEE 802.11bn standard is the successor to the IEEE 802.11be standard, which aims for a maximum transmission speed of 46.08 Gbps (Gigabits per second). The main features of the IEEE 802.11bn standard are that it has functions that realize highly reliable communication, low latency communication, and improved throughput when communication traffic is congested. The wireless frame used in a communication method compliant with this standard may be called a UHR (Ultra High Reliability) PPDU. PPDU is an abbreviation for PLCP Protocol Data Unit, and PLCP is an abbreviation for Physical Layer Convergence Protocol. Note that the names UHR and IEEE 802.11bn, etc., may be changed to different names once the standard is finalized. Also note that this specification and the claims attached herein are applicable to communication devices using all successor standards to IEEE 802.11be. Furthermore, the communication device 100 may correspond to at least one of the legacy standards that precede the IEEE 802.11bn standard. Legacy standards include, for example, the IEEE 802.11a / b / g / n / ac / ax / be standards. Furthermore, the communication device 100 may support other communication standards such as Bluetooth®, NFC, UWB, ZigBee, and MBOA. UWB is an abbreviation for Ultra Wide Band, and MBOA is an abbreviation for Multi Band OFDM Alliance. NFC is an abbreviation 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. AP101 is, for example, a wireless LAN router or a personal computer (PC), but is not limited to these. AP101 may be an information processing device such as a wireless chip capable of performing wireless communication compliant with the IEEE 802.11bn standard, etc.STA110 is, for example, a camera, tablet, smartphone, PC, mobile phone, video camera, headset, smart glasses, HMD (head-mounted display) and other wearable devices, but is not limited to these. STA110 may be an information processing device such as a wireless chip capable of performing wireless communication that supports the transmission and reception of PPDUs compliant with the IEEE 802.11bn standard, etc. In this case, it can be configured to perform various controls by hardware circuits inside the wireless chip. It can also be configured so that various processes are performed by the cooperation of a processor such as an ASIP, memory and hardware circuits inside the wireless chip. ASIP is an abbreviation for Application-specific instruction set processor.

[0013] The communication device 100 can 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 millimeter wave bands such as the 45 GHz band and 60 GHz band. The frequency bands used by the communication device 100 are not limited to these, and may include, for example, the Sub1 GHz band. Furthermore, the communication device 100 can communicate using bandwidths of 20 MHz, 40 MHz, 80 MHz, 160 MHz, 320 MHz, 540 MHz, 640 MHz, 1080 MHz, and 2160 MHz. The bandwidths used by the communication device 100 are not limited to these, and may include, for example, 240 MHz or 4 MHz. Note that the IEEE 802.11 standard series specifies frequency channels using a bandwidth of 20 MHz as basic channels in frequency bands such as the 2.4 GHz, 5 GHz, and 6 GHz bands. Furthermore, this standard defines multiple available channels in the 2.4 GHz, 5 GHz, and 6 GHz frequency bands. In this standard, the communication device 100 can use one channel in combination with other adjacent channels. This use of one channel in combination with other adjacent channels may be called channel bonding. A bundle of channels formed by one or two or more adjacent channels may be called a communication link. That is, one link formed by two channels with a bandwidth of 20 MHz may use a bandwidth of 40 MHz. The IEEE 802.11be standard and its successors (including the IEEE 802.11bn standard and its successors) are expected to specify a maximum bandwidth of 320 MHz or more for a single link. For example, a link using a 320 MHz bandwidth may be formed by bundling 16 channels with a bandwidth of 20 MHz using channel bonding. The signals transmitted in this band may be continuous or discontinuous on the frequency axis. Furthermore, AP101 and STA110 may be AP MLDs (Multi-Link Devices) and STA MLDs, respectively, that support Multi-Link, which establishes and communicates through multiple links simultaneously.

[0014] The communication device 100 establishes one or more links between devices in order to communicate data with other communication devices. For example, STA 110 performs a connection procedure with AP 101 to establish a link with AP 101. The connection procedure includes, for example, STA 110 sending a connection request and AP 101 sending a connection response. Upon completion of the connection procedure, a link is established between STA 110 and AP 101. The establishment of a link is sometimes referred to as establishing a connection. With the link established, the communication device 100 can access the wireless medium and communicate data, etc., with the other communication device. For example, if one link using a bandwidth of 320 MHz is established between devices, the communication device 100 can perform communication by channel bonding using all or some of the channels that constitute the link, depending on the channel status.

[0015] When the communication device 100 transmits a signal using a link established with another communication device, it performs carrier sensing to determine whether or not to transmit. Carrier sensing is the operation in which the communication device 100 determines whether or not there is a signal on the channel that it intends to use for transmission. For example, the communication device 100 measures the strength of the signal received on the channel (received signal strength) and determines that a signal exists if the received signal strength exceeds a predetermined threshold (physical carrier sensing). The received signal strength may also be called the Received Signal Strength Indicator (RSSI). The communication device 100 may also determine the presence or absence of a signal based on information such as the Duration field contained in the signal received on the channel (virtual carrier sensing). For example, the communication device 100 stores the period indicated by the Duration field contained in the received signal as a Network Allocation Vector (NAV) within its own device. The communication device 100 can treat the stored NAV as a period during which it does not transmit. In this embodiment, the operation by which the communication device 100 sets a period during which it does not transmit based on information such as the Duration field of the received signal is called setting the NAV. That is, until the NAV set for the channel expires, the communication device 100 determines that a signal is present on the channel. In this way, the communication device 100 determines whether or not a signal is present on the channel based on the results of performing physical carrier sensing and virtual carrier sensing. If the communication device 100 determines that a signal is present on the channel, it may determine that the channel is in a state where it cannot transmit. In this case, the state of the channel may be called a busy state. On the other hand, a state in which no signal is detected on the channel in carrier sensing and no NAV is set may be called an idle state. If the communication device 100 is in an idle state, it may determine that the channel is in a state where it can transmit.

[0016] When communication is performed using a link with a predetermined bandwidth, the communication device 100 may determine whether transmission is possible using only the 20 MHz bandwidth Primary Channel (PCH) included in that link. For example, the PCH is one of 16 20 MHz bandwidth channels that make up a 320 MHz bandwidth link. In this case, the communication device 100 may determine that transmission is impossible based on the PCH being busy, or that transmission is possible based on the PCH being idle. Therefore, if the communication device 100 determines that transmission is impossible as a result of carrier sensing on the PCH, it may postpone transmission even if other channels included in the same link are idle. Note that each channel other than the PCH that makes up a single link may be called a secondary channel (SCH). Secondary channels may also be called non-primary channels (NPCH).

[0017] The IEEE 802.11 standard series specifies a function that increases communication speed by enabling AP101 to perform multi-user (MU) communication, where it multiplexes radio resources and communicates simultaneously with multiple STA110s. For example, AP101 can communicate in parallel with multiple STA110s using OFDMA. OFDMA is an abbreviation for Orthogonal Frequency Division Multiple Access. In OFDMA, multiple units are formed on the frequency axis in a PPDU transmitted using a frequency channel of a predetermined bandwidth. Each of these units is called a Resource Unit (RU). AP101 assigns one or more different RUs to each STA110. Multi-user communication can be performed by AP101 communicating in parallel with each STA110 using the RU assigned to each STA110. The predetermined bandwidth can be 20MHz, 40MHz, 80MHz, 160MHz, 320MHz, etc. Each RU is composed of multiple subcarriers. For example, an RU composed of 26 subcarriers is called a 26-tone RU. Based on the number of subcarriers that make up the RU, 26-tone RUs, 52-tone RUs, 106-tone RUs, 242-tone RUs, 484-tone RUs, 996-tone RUs, etc. can be configured.

[0018] Here, the usable frequency bandwidth of the communication device 100 may vary depending on the communication device 100. For example, suppose AP 101 can use a bandwidth up to 320 MHz, while STA 111 and STA 112 can each use a bandwidth up to 80 MHz. In this case, according to the current IEEE 802.11 standard series, the frequency bandwidth used for communication between AP 101 and each STA 110 will be the 80 MHz bandwidth including the PCH within the 320 MHz frequency bandwidth used by the AP. The 80 MHz channel including the PCH is called the Primary 80 MHz Channel. Therefore, when AP 101 communicates with STA 111 and STA 112 using OFDMA, it will form multiple RUs in the 80 MHz frequency bandwidth of the Primary 80 MHz Channel and assign an RU to each STA 110. Figure 2 shows an example sequence when AP101 communicates with STA111 and STA112 using OFDMA on the primary 80MHz channel. At time t0, AP101 starts transmitting PPDUs to STA111 and STA112 respectively. At time t1, STA111 and STA112 each start transmitting PPDUs to AP101. Furthermore, at time t2, AP101 starts transmitting PPDUs to STA111 and STA112 respectively. In all cases, communication is performed using the 80MHz frequency band (primary 80MHz channel) including the PCH, and the RU used between AP101 and each STA110 is a part of this 80MHz frequency band. Thus, even if AP101 can use a bandwidth of 320 MHz, if each STA110 can use a bandwidth of 80 MHz, the frequency band used between AP101 and the multiple STA110s is limited to the primary 80 MHz channel. As a result, there are unused frequency resources in the frequency band that AP101 can use, and these unused frequency resources become larger the greater the difference between the bandwidth that AP101 can use and the bandwidth that STA110 can use.For example, in Figure 2, the 240 MHz bandwidth will not be used.

[0019] In light of these circumstances, AP101 in this embodiment allocates frequency resources in frequency division multiplexing communication with multiple STA110s based on whether or not it has the ability to change the frequency band used by STA110 to perform communication. For example, suppose that in the first frequency band of the first bandwidth used by AP101 for communication, there is a second frequency band determined based on the second bandwidth that STA110 can handle, and a third frequency band other than the second frequency band. For example, in the example in Figure 2, the first bandwidth is 320 MHz and the second bandwidth is 80 MHz. The first frequency band is the 320 MHz frequency band usable by AP101, the second frequency band is the 80 MHz frequency band usable by STA111 and STA112, and the third frequency band is the unused 240 MHz frequency band. First, AP101 obtains capability information from STA110 indicating whether or not STA110 has the capability to change the frequency band used to perform frequency division multiplexing communication from the second frequency band to a fourth frequency band that includes a portion of the third frequency band. Based on the fact that STA110 does not have the capability, AP101 allocates frequency resources to STA110 from the second frequency band. Alternatively, based on the fact that STA110 has the capability, AP101 allocates frequency resources to STA110 from the second frequency band, or from the fourth frequency band after STA110 changes the frequency band it uses to the fourth frequency band. Meanwhile, STA110 notifies AP101 of the capability information indicating whether or not it has the capability. STA110 identifies the frequency resources in the second frequency band that were allocated to it based on the fact that its device does not have the capability. Furthermore, STA110 identifies frequency resources in a second or fourth frequency band, which are allocated to it based on the fact that its device has a predetermined capability. If STA110 is allocated frequency resources in the fourth frequency band, it changes the frequency band to be used to the fourth frequency band. AP101 and STA110 communicate using the frequency resources allocated to STA110.With this configuration, STA 110 can change to the fourth frequency band and participate in frequency division multiplexing communication with AP 101 if the frequency resources of the second frequency band are allocated to an STA 110 other than its own communication device. By changing the frequency band used while maintaining the bandwidth used by STA 110 in this way, AP 101 can perform frequency division multiplexing communication using a wide bandwidth even if the corresponding bandwidth of each STA 110 is narrow. An example of the configuration and processing of a communication device 100 that operates in this manner will be described below.

[0020] (Overview of DSO) First, an overview of the operation of the Dynamic Subband Operation (DSO) performed by the communication device 100 of this embodiment will be described. Between AP 101 and STA 110, which are capable of performing DSO, multiple frequency domains are set within the frequency band used by AP 101. The multiple frequency domains may be set so as not to overlap with each other, or they may be set so that some overlap occurs. Each frequency domain may be explicitly set as a range on the frequency axis. Alternatively, each frequency domain may be implicitly set by setting either its lower or upper end, and the bandwidth available to STA 110 based on that lower or upper end. The setting of each frequency domain is not limited to these, and it is sufficient that the target when changing the frequency band used by STA 110 is indicated. For example, each frequency domain may be indicated using the distance on the frequency axis or its relationship to the PCH, with the PCH as the reference. The relationship with the PCH can be expressed as Secondary 20MHz Channel, Secondary 40MHz Channel, Secondary 80MHz Channel, Secondary 160MHz Channel, etc. Alternatively, the relationship with the PCH can be expressed as Primary 20MHz Channel, Primary 40MHz Channel, Primary 80MHz Channel, Primary 160MHz Channel, etc. Each frequency domain can be called a segment, subblock, subband, etc. If there are two frequency domains to be defined, the frequency domain containing the PCH may be defined as the primary channel or primary band, and the frequency domain not containing the PCH may be defined as the secondary channel or subband. Figure 3 shows an example where AP101, which uses a frequency band with a bandwidth of 320 MHz, sets four frequency domains, from the first to the fourth, in relation to STA110, which is capable of using a bandwidth of 80 MHz. Each frequency domain can be set with the bandwidth available to STA110 as a single unit. AP101 may also set a frequency domain that is commonly used in the BSS that constitutes its own device. In this case, a bandwidth larger than the bandwidth available to STA110 may be set.For example, in Figure 3, two frequency domains with a bandwidth of 160 MHz may be set. In this case, the frequency band used by STA110 will be the frequency band of the bandwidth available to STA110 that is included in each frequency domain. Each frequency domain may consist of different bandwidths. AP101 can set frequency domains according to the bandwidth available to STA110. For example, if the bandwidth available to STA110 is 20 MHz, AP101 can set up to eight frequency domains with a bandwidth of 40 MHz, up to four frequency domains with a bandwidth of 80 MHz, two frequency domains with a bandwidth of 160 MHz, etc.

[0021] STA110 communicates with AP101 while changing the frequency band it uses in response to a notification from AP101. Changing the frequency band used by STA110 can be described as moving along the frequency axis. For example, in Figure 3, suppose AP101 and STA110 are communicating data 301 in a first frequency domain including PCH at times t0 to t1. At time t2, AP101 sends a notification 302 to STA110 indicating that it should move to a third frequency domain. AP101 may explicitly notify STA110 that it should move to a third frequency domain, or it may implicitly notify STA110 using a frequency resource notification by specifying the frequency domain that contains the frequency resources to be allocated to STA110. In response to this notification 302, STA110 moves to the third frequency domain. Then, AP101 and STA110 communicate data 303 in the third frequency domain. In parallel with the communication of data 303, AP101 communicates with other STA110s in the first frequency domain using frequency division multiplexing. Once the communication of data 303 is complete, STA110 can return to the first frequency domain. In this way, by switching the frequency band used by STA110 in response to notifications from AP101, AP101 can communicate with STA110s while effectively utilizing the frequency resources in the frequency band available to its device.

[0022] Alternatively, instead of setting the frequency range as described above, a distance to be moved on the frequency axis to change the frequency band used by STA110 may be set. For example, in Figure 3, the lower end of the 320 MHz frequency band used by AP101 may be set as the first frequency, and second, third, and fourth frequencies may be set at 80 MHz intervals. In this case, STA110 may set a frequency band with one of the first to fourth frequencies as its lower end as the frequency band used by its device, based on a notification from AP101. Each of the first to fourth frequencies may be called a frequency switching position.

[0023] (Device Configuration) Figure 4 shows an example of the hardware configuration of the communication device 100 of this embodiment. As an example of its hardware configuration, the communication device 100 has, for example, a storage unit 401, a control unit 402, a function unit 403, an input unit 404, an output unit 405, a communication unit 406, and an antenna 407. The communication device 100 may have multiple antennas.

[0024] The storage unit 401 is composed of one or more memories, including ROM and RAM, and may store control programs for various operations of each functional unit constituting the communication device 100, as well as various information such as parameters for communication. ROM and RAM are abbreviations for Read Only Memory and Random Access Memory, respectively. In addition to memories such as ROM and RAM, the storage unit 401 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.

[0025] The control unit 402 is composed of one or more processors, such as a CPU and an MPU, and controls the entire communication device 100 by executing a control program stored in the storage unit 401. Alternatively, the control unit 402 may control the entire communication device 100 through cooperation between the control program stored in the storage unit 401 and the OS (Operating System). CPU and MPU are abbreviations for Central Processing Unit and Micro Processing Unit, respectively. If the control unit 402 has multiple processors that can be implemented as a multi-core system, the entire communication device 100 may be controlled by these multiple processors.

[0026] Furthermore, the control unit 402 controls the functional unit 403 to perform predetermined processes such as communication, imaging, printing, and projection. The functional unit 403 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 403 is the imaging unit and performs imaging processing. Also, for example, if the device is a printer, the functional unit 403 is the printing unit and performs printing processing. Also, for example, if the device is a projector, the functional unit 403 is the projection unit and performs projection processing.

[0027] The input unit 404 receives various operations from the user. The output unit 405 outputs various information to the user via a monitor screen or speaker. The output from the output unit 405 may be a display on the monitor screen, audio output via a speaker, vibration output, etc. The input unit 404 and the output unit 405 may both be implemented in a single module, such as a touch panel. The input unit 404 and the output unit 405 may each be an integrated device with the communication device 100, or they may be separate devices.

[0028] The communication unit 406 controls wireless communication in accordance with the IEEE 802.11bn standard. In addition to the IEEE 802.11bn standard, the communication unit 406 may also control wireless communication in accordance with other IEEE 802.11 standard series, such as legacy standards. The communication unit 406 controls the antenna 407 to transmit and receive signals for wireless communication generated by the control unit 402. The communication unit 406 is a so-called wireless chip and may itself have one or more processors and memory. If the communication device 100 supports other wireless communication standards such as NFC and Bluetooth standards, or wired communication such as wired LAN, in addition to the IEEE 802.11bn standard, the communication unit 406 may also control communication in accordance with these communication standards. Furthermore, if the communication device 100 can perform wireless communication in accordance with multiple communication standards, the communication device 100 may be configured to have separate communication units and antennas corresponding to each communication standard. The communication device 100 communicates data with the other party's communication device via the communication unit 406. The antenna 407 may be configured separately from the communication unit 406, or it may be configured as a single module together with the communication unit 406.

[0029] Antenna 407 is an antenna capable of communication in millimeter waves such as the 2.4 GHz band, 5 GHz band, 6 GHz band, 45 GHz band, and 60 GHz band. Figure 4 shows a configuration in which the communication device 100 has two antennas 407, but the communication device 100 may have one or more antennas, or one or more antennas for each frequency band that the device can use. Furthermore, if the communication device 100 has multiple antennas, the communication device 100 may have a communication unit 406 for each antenna.

[0030] (Functional Configuration) Figure 5 shows an example of the functional configuration of AP101. The functional configuration in this embodiment is an example of a functional configuration realized by one or more processors executing programs stored in one or more memories. AP101 may be configured to include a wireless communication control unit 501, an information acquisition unit 502, a resource allocation unit 503, and a DSO control unit 504.

[0031] The wireless communication control unit 501 controls communication with the STA 110. For example, the wireless communication control unit 501 can send and receive frames necessary for performing OFDMA communication with the STA 110. As an example, the wireless communication control unit 501 can send UHR MU PPDU and Trigger frames and receive UHR TB PPDUs. The wireless communication control unit 501 can adjust the length of the frame to be transmitted based on the time required for the STA 110 to move on the frequency axis when performing DSO.

[0032] The information acquisition unit 502 acquires information related to STA 110. For example, the information acquisition unit 502 may acquire information that determines whether or not STA 110 has the capability to perform communication using DSO. The information acquisition unit 502 may also acquire information indicating the distance that STA 110 can travel on the frequency axis when performing communication using DSO. Furthermore, the information acquisition unit 502 may acquire information indicating the time required for STA 110 to travel on the frequency axis. The information acquired by the information acquisition unit 502 can be used by the resource allocation unit 503 and the DSO control unit 504.

[0033] The resource allocation unit 503 performs the allocation of frequency resources to STA 110. For example, when the wireless communication control unit 501 communicates with STA 110 using OFDMA, the resource allocation unit 503 may select a frequency range to allocate frequency resources based on whether or not STA 110 has the capability to perform DSO. Alternatively, the resource allocation unit 503 may select a frequency range to allocate frequency resources to STA 110 based on the distance STA 110 can move along the frequency axis. The resource allocation unit 503 allocates the frequency resources included in the selected frequency range to STA 110. If the resource allocation unit 503 allocates frequency resources from a frequency range other than the first frequency range to STA 110, it may notify STA 110 that it should move along the frequency axis.

[0034] The DSO control unit 504 controls the communication using DSO with the STA 110. For example, the DSO control unit 504 decides whether or not to perform DSO communication with the STA 110 based on whether or not the STA 110 has the capability to perform DSO. The DSO control unit 504 may also decide whether or not to perform DSO communication with the STA 110 based on the distance the STA 110 can move on the frequency axis and the time required to move. The DSO control unit 504 may set multiple frequency ranges or one or more frequency switching positions as destinations for changing the frequency band used by the STA 110.

[0035] Figure 6 shows an example of the functional configuration of STA110. The functional configuration in this embodiment is an example of a functional configuration realized by, for example, one or more processors executing programs stored in one or more memories. STA110 may be configured to include a wireless communication control unit 601, an information notification unit 602, an information acquisition unit 603, and a frequency band control unit 604.

[0036] The wireless communication control unit 601 controls communication with AP 101. For example, the wireless communication control unit 501 can send and receive frames necessary for performing OFDMA communication with AP 101. As an example, the wireless communication control unit 501 can receive UHR MU PPDU and Trigger frames and transmit UHR TB PPDUs. The wireless communication control unit 601 communicates with AP 101 using the frequency resources allocated to its own device.

[0037] The information notification unit 602 notifies AP 101 of information relating to its own device. For example, the information notification unit 602 may notify AP 101 of information indicating whether or not its own device has the capability to perform communication using DSO. In addition, the information notification unit 602 may notify AP 101 of information indicating the distance that its own device can travel on the frequency axis when performing communication using DSO. Furthermore, the information notification unit 602 may notify AP 101 of information indicating the time required for its own device to travel on the frequency axis.

[0038] The information acquisition unit 603 acquires information from AP 101. The information acquisition unit 603 may acquire information that identifies whether AP 101 has the capability to perform communication using DSO. The information acquisition unit 603 may also acquire information that identifies the delay time that AP 101 allows in communication using DSO. Furthermore, the information acquisition unit 603 may acquire information that identifies the frequency resources allocated to its own device. The information identifying the frequency resources acquired by the information acquisition unit 603 can be used by the wireless communication control unit 601, the frequency band control unit 604, etc.

[0039] The frequency band control unit 604 controls the frequency band used by the device. For example, in its normal state, the frequency band control unit 604 sets the first frequency domain, which includes the PCH, as the frequency band used by the device. If the frequency resources allocated to the device are included in a frequency domain other than the first frequency domain, the frequency band control unit 604 sets the frequency domain including those frequency resources as the frequency band used by the device. Furthermore, when communication in that frequency band is completed, the frequency band control unit 604 returns the used frequency band to the first frequency domain. In addition, if the frequency band control unit 604 is notified by AP101 to move along the frequency axis, it may change the frequency band used in accordance with that notification.

[0040] (Processing Flow) Below, we will describe some examples of the processing flow performed by AP101 and each STA in this embodiment.

[0041] (Sharing of Capability Information for Executing Communication Using DSO) AP101 and STA110 can share information regarding the capability of each communication device to execute DSO when establishing a connection between the devices. The operations performed by each communication device when a connection is established between AP101 and STA110 will be explained using Figure 7. Figure 7 shows an example of a sequence of processes performed when a connection is established between AP101 and STA110. This sequence may be executed, for example, when the power of STA110 is turned on and the connection with AP101 is started. First, AP101 periodically transmits Beacon frames (F701). The Beacon frame may contain capability information of AP101 and communication parameters to be used in the BSS configured by AP101. Capability information may be called Capabilities information. Communication parameters may be called Operation information. The BSS configured by AP101 is sometimes called its own BSS. For example, AP101 may transmit information about its capabilities, such as the frequency bandwidth available to it and its ability to perform DSO, via a Beacon frame. AP101 may also transmit information in a Beacon frame that identifies the frequency bandwidth and PCH used by its BSS, and that identifies whether DSO is enabled or disabled, as communication parameters. STA110 receives the Beacon frame transmitted from AP101. Using the received Beacon frame, STA110 can identify the frequency bandwidth and PCH used by AP101, and determine whether AP101 has the capability to use DSO, whether DSO is enabled, etc.

[0042] STA110 initiates the connection procedure by sending a Probe Request frame to AP101 based on the information obtained from the Beacon frame (F702). The Probe Request frame may contain STA110's capability information and communication parameters. For example, STA110 may send information in the Probe Request frame indicating its own capability information, such as the frequency bandwidth available to it, whether it has the capability to perform DSO, and whether DSO is enabled or disabled. For example, STA110 may notify AP101 that it has the capability to perform DSO using the UHR Capabilities element and UHR Operation element included in the Association Request frame. Furthermore, if AP101 does not transmit a Beacon, or if STA110 is unable to properly receive the Beacon transmitted by AP101, STA110 may initiate the connection procedure without receiving a Beacon. For example, STA110 may initiate the connection procedure by transmitting a Probe Request frame using an SSID (Service Set Identifier) ​​or the like that has been registered in advance by the user.

[0043] When AP101 receives a Probe Request frame, it transmits a Probe Response frame (F703). In the Probe Response frame, AP101 may notify STA110 of its own device capability information and communication parameters to be used in its BSS. AP101 and STA110 authenticate each other's communication devices by exchanging Authentication frames (F704).

[0044] When the authentication of the communication device of the other party is completed, STA110 transmits an Association Request frame (F705). STA110 may notify the AP101 of its own device's capability information and communication parameters using the Association Request frame. When the AP101 receives the Association Request frame, it transmits an Association Response frame (F706). The AP101 may notify the STA110 of its own device's capability information and the communication parameters of its own BSS using the Association Response frame. When the STA110 receives the Association Response frame from the AP101, the connection between the AP101 and the STA110 is established, and the connection procedure ends. Note that the AP101 and the STA110 can subsequently execute a 4-way Handshake for sharing security information.

[0045] AP101 and STA110 can exchange information for performing DSO during the connection procedure. For example, AP101 and STA110 can notify each other of information indicating whether their own device has the capability to perform DSO, and can obtain information indicating whether the other communication device has the capability to perform DSO. Based on the fact that STA110 has the capability to perform DSO, AP101 can allocate frequency resources included in frequency domains other than the first frequency domain set between AP101 and STA110 to STA110. Based on the fact that AP101 has the capability to perform DSO, STA110 can start exchanging information necessary for performing DSO between its own device and AP101. AP101 and STA110 can notify each other of information indicating whether their own device has enabled or disabled the function to perform DSO, and can obtain information indicating whether the other communication device has enabled or disabled the function to perform DSO. Each communication device 100 may disable the DSO function due to interference in the surroundings, etc., even if its own device has the capability to perform DSO. By exchanging information indicating whether or not the DSO function is enabled, it becomes possible to determine whether the communication device of one device and the other device are in a state where DSO can be executed. AP101 and STA110 may also determine that the other device does not have the ability to execute DSO if the frame received from the other device does not contain a UHR Capabilities element. This makes it possible to notify the other device of whether or not it has the ability to execute DSO without having to include a field in the UHR Capabilities element to notify whether or not it has the ability to execute DSO.

[0046] AP101 and STA110 can exchange information indicating the distance STA110 can move on the frequency axis when performing DSO. This allows AP101 and STA110 to set multiple frequency domains within the frequency band used by AP101. For example, AP101 can set multiple frequency domains within the range usable by STA110 in the frequency band used by its own device by obtaining the bandwidth available to STA110. For example, if AP101 is using a frequency band with a bandwidth of 320 MHz and the available bandwidth of STA110 is 80 MHz, AP101 can set four frequency domains, from the first to the fourth. In this case, if the distance STA110 can move on the frequency axis is 80 MHz, STA110 cannot use the third and fourth frequency domains. In this case, AP101 sets two frequency domains with a bandwidth of 80 MHz between itself and STA110. In this way, by sharing information between AP101 and STA110 that indicates the distance STA110 can move on the frequency axis when performing DSO, it becomes possible to set a frequency range that can be set as the frequency band used by STA110.

[0047] Furthermore, AP101 and STA110 can exchange information indicating the time required for STA110 to move along the frequency axis when performing DSO. The time required for STA110 to move along the frequency axis when performing DSO may be called frequency switching delay. As a result, AP101 may determine that it will not perform DSO with STA110 if STA110's frequency switching delay exceeds the time that its own device can tolerate for performing DSO. Also, if STA110's frequency switching delay exceeds a predetermined time, AP101 may perform control to assist STA110's DSO. The predetermined time may be a time defined by standards such as Short Interface Space (SIFS). For example, AP101 may adjust the length of the frame transmitted by its own device as control to assist STA110's DSO. For example, AP101 may use the frequency switching delay of STA110 to determine the length of the frame when performing DSO. As an example, AP101 may add padding corresponding to the frequency switching delay of STA110 in a frame that notifies STA110 to move to another frequency domain. The padding may be pseudo-data to adjust the length of the frame. This may ensure that the time necessary for STA110 to move to the other frequency domain is secured. Note that the first frequency switching delay when STA110 moves from the first frequency domain to another frequency domain may differ from the second frequency switching delay when STA110 moves from another frequency domain to the first frequency domain. In this case, AP101 may obtain both the first and second frequency switching delays from STA110. Furthermore, AP101 can add padding according to the cases in which STA110 moves from the first frequency domain to another frequency domain, and from another frequency domain to the first frequency domain. AP101 may also identify a frequency domain in which at least one or both of the first frequency switching delay and the second frequency switching delay satisfy a predetermined threshold as a frequency domain in which STA110 can be used for DSO.Also, when the frequency switching delay varies depending on the distance that STA110 moves on the frequency axis, AP101 can obtain the frequency switching delay for each frequency region. For example, AP101 can obtain each of the first frequency switching delays for STA110 to move to the second frequency region, the third frequency region, and the fourth frequency region respectively, based on the first frequency region. Also, AP101 can obtain each of the second frequency switching delays for STA110 to move from the second frequency region, the third frequency region, and the fourth frequency region to the first frequency region. In this case, AP101 can add padding to the frame for notifying STA110 to move to another frequency region according to the frequency switching delay corresponding to the frequency region including the frequency resource assigned to STA110.

[0048] AP101 can notify STA110 of the allowable time that can be tolerated as the frequency switching delay of STA110 when the self-device executes DSO. This allowable time can be notified by a Beacon frame or the like. When STA110 obtains this allowable time, it can determine whether the frequency switching delay of its own device exceeds the allowable time of AP101. Based on the fact that the frequency switching delay of its own device exceeds the allowable time of AP101, STA110 can invalidate DSO. In this case, STA110 can notify AP101 that its own device has invalidated DSO. Thereby, information exchange for executing DSO between AP101 and STA110 can be skipped. Also, when the frequency switching delay of STA110 varies depending on the distance it moves on the frequency axis, STA110 can notify AP101 of information indicating the distance that can be moved within the range not exceeding the allowable time of AP101. Thereby, information exchange for executing DSO between AP101 and STA110 can be simplified.

[0049] AP101 may notify STA110 of its own device capability information and communication parameters using Beacon frames, Probe Response frames, Association Response frames, etc. STA101 may notify AP101 of its own device capability information and communication parameters using Probe Request frames, Association Request frames, etc. AP101 and STA110 may voluntarily notify each other of their own device capability information, etc., or they may notify each other of their own device capability information, etc., based on a request from the other party's communication device. Furthermore, AP101 and STA110 may passively acquire capability information by waiting for notification of capability information from the other party's communication device, or they may actively acquire capability information by making a request to the other party's communication device. AP101 can efficiently notify an unspecified number of STA110s of its capabilities by broadcasting its own capabilities information using Beacon frames. Furthermore, by having STA110 acquire AP101's capabilities information before starting the connection procedure with STA110, the amount of information exchanged during the connection procedure can be reduced. Note that FILS Discovery frames may be used instead of Beacon frames. FILS Discovery frames may be used to broadcast only a portion of the information contained in Beacon frames (such as SSID and channel information).

[0050] (Configuration of information on the capability to perform DSO) The configuration of the information used by the communication device 100 when it notifies the other party's communication device of its own capability information regarding DSO is described below. Figure 8 shows an example of the configuration of information elements used by the communication device 100 when it notifies the other party's communication device of its own capability information regarding DSO. Information elements may be called Information Element (IE). The information elements in Figure 8 may be called UHR Capabilities elements. UHR Capabilities elements may be included in Beacon frames, Probe Response frames, Association Response frames, etc. Also, UHR Capabilities elements may be included in Probe Request frames, Association Request frames, etc. The UHR Capabilities element may be included in frames other than these. For example, the UHR Capabilities element may be included in the Action frame. This makes it possible to change values ​​such as frequency switching delay depending on the surrounding conditions, for example, after the connection between AP101 and STA110 has been established.

[0051] The UHR Capabilities element includes an Element ID field 801, a Length field 802, and an Element ID Extension field 803. The UHR Capabilities element may also include a DSO Transmit Capable (DTC) field 804 and a DSO Receive Capable (DRC) field 805. Furthermore, the UHR Capabilities element may include a DSO padding delay field 806, a DSO Transaction Delay field 807, and a DSO Subbandwidth field 808. Furthermore, the UHR Capabilities element may include a DSO Padding Timeout field 809 and a DSO Transition Timeout field 810.

[0052] The combination of the Element ID field 801 and the Element ID Extension field 803 indicates the type of information element. For example, if the Element ID field 801 is set to 255 and the Element ID Extension field 803 is set to 138, it indicates that this information element is a UHR Capabilities element. The Length field 802 indicates the length of this information element. The DTC field 804 indicates whether the communication device 100 has the capability to perform transmission processing in the DSO. Alternatively, the DSO UL Capable field may be included instead of the DTC field 804. The DSO UL Capable field indicates whether the communication device 100 has the capability to perform uplink data processing in the DSO. The DRC field 805 indicates whether the communication device 100 has the capability to perform receiving processing in DSO. Alternatively, the DSO DL Capable field may be included instead of the DRC field 805. The DSO DL Capable field indicates whether the communication device 100 has the capability to perform downlink data processing in DSO. Furthermore, the DTC field 804 and the DRC field 805 may be configured as a single field. In this case, this single field indicates whether the communication device 100 has the capability to perform DSO. A value of 1 in these fields indicates that the communication device 100 has the capability to perform DSO, while a value of 0 indicates that the communication device 100 does not have the capability to perform DSO. The communication device 100 may implicitly indicate its ability to perform DSO by transmitting a frame containing the UHR Capabilities element. In this case, if the bandwidth available to STA110 is smaller than the bandwidth of the frequency band used by AP101, then STA110 can be interpreted as being capable of DSO operation. For example, if the bandwidth of the frequency band used by AP101 is 320 MHz, then a communication device 100 operating with a bandwidth up to 160 MHz can be interpreted as being capable of performing DSO.Furthermore, the UHR Capabilities element may include a field indicating whether the communication device 100 has enabled or disabled the DSO, in addition to the DTC field 804 and the DRC field 805. This field may also be included in information elements other than the UHR Capabilities element. For example, this field may be included in the UHR Operation element.

[0053] The DSO padding delay fields 806 to DSO Subbandwidth field 808 may be included in the frame transmitted by STA110. Additionally, the DSO Padding Timeout field 809 and DSO Transaction Timeout field 810 may be included in the frame transmitted by AP101. If the frame transmitted by AP101 includes the DSO padding delay fields 806 to DSO Subbandwidth field 808, these fields may be treated as reserved areas. Furthermore, if the frame transmitted by STA110 includes the DSO Padding Timeout field 809 and DSO Transaction Timeout field 810, these fields may be treated as reserved areas. The above fields may exist when a value of 1 is set in the DTC field 804 or the DRC field 805, that is, when the communication device 100 has the ability to perform DSO.

[0054] The DSO padding delay field 806 indicates the time required for STA 110 to move along the frequency axis when performing DSO (frequency switching delay). For example, the DSO padding delay field 806 may indicate a first frequency switching delay required for STA 110 to move from a first frequency domain to another frequency domain. The first frequency switching delay may be the time required from when STA 110 finishes receiving the User Info field assigned to its device in the Trigger frame described later until it becomes ready to communicate in the other frequency domain. An example configuration of the DSO padding delay field 806 is shown in Table 1. Table 1 shows the values ​​set in the DSO padding delay field 806 and the corresponding time when the DSO padding delay field 806 is configured with 3 bits. For example, if the UHR Capabilities element received by STA110 contains a DSO padding delay field 806, AP101 can determine the first frequency switching delay of STA110 based on Table 1. If the first frequency switching delay differs depending on the distance STA110 moves along the frequency axis, DSO padding delay fields 806 corresponding to each distance may be provided.

[0055] Table 1

[0056] The DSO Transition delay field 807 indicates the time required for STA 110 to move along the frequency axis when performing DSO (frequency switching delay). For example, the DSO Transition delay field 807 may indicate a second frequency switching delay required for STA 110 to move from another frequency domain to the first frequency domain. An example configuration of the DSO Transition delay field 807 is shown in Table 2. Table 2 shows the values ​​set in the DSO Transition delay field 807 and the corresponding times when the DSO Transition delay field 807 is configured with 3 bits. For example, if the UHR Capabilities element received by STA110 contains a DSO Transition delay field 807, AP101 can determine the second frequency switching delay of STA110 based on Table 2. If the second frequency switching delay differs depending on the distance STA110 moves along the frequency axis, DSO Transition delay fields 807 corresponding to each distance may be provided.

[0057] Table 2

[0058] The DSO Subbandwidth field 808 indicates information that shows the distance that STA 110 can move on the frequency axis when performing DSO. The distance that can move may be the distance that STA 110 can move on the frequency axis when moving from a state in which it is communicating in a predetermined frequency band to a state in which it is communicating in a different frequency band. The distance that can move may also be the distance that STA 110 can move on the frequency axis to change the frequency band used by AP 101 within the allowable time range for AP 101 to perform DSO. An example configuration of the DSO Subbandwidth field 808 is shown in Table 3. Table 3 shows the values ​​set in the DSO Subbandwidth field 808 and the frequencies corresponding to those values ​​when the DSO Subbandwidth field 808 is configured with 3 bits. For example, if the UHR Capabilities element received by STA110 contains the DSO Subbandwidth field 808, AP101 can determine the travelable distance of STA110 based on Table 3. For example, suppose the DSO Subbandwidth field 808 is set to a value of 3, and the usable frequency bandwidth of STA110 is set to 80 MHz. In this case, it may be shown that STA110 can switch between using a frequency range from a first frequency domain of 80 MHz bandwidth to a range of 80 MHz. For example, it may be shown that STA110 can use the first frequency domain to the second frequency domain of 80 MHz bandwidth in Figure 3. The travelable distance may also indicate the frequency bandwidth that STA110 becomes usable by performing DSO. For example, suppose that the usable bandwidth of STA110 is 80 MHz, and that a bandwidth of 160 MHz becomes available when the value of 4 is set in the DSO Subbandwidth field 808. This indicates that STA110, which has an usable bandwidth of 80 MHz, can now move its bandwidth beyond 80 MHz due to the DSO, resulting in an expansion of the bandwidth range that STA110 can use for communication to 160 MHz.

[0059] The DTC field 804, the DRC field 805, and the DSO Subbandwidth field 808 may be configured as a single field. In this case, if the value of 0 is set in this field, it may indicate that the communication device 100 cannot perform DSO. Conversely, if a value other than 0 is set in this field, it may indicate that the communication device 100 can perform DSO. On the other hand, if the DSO Subbandwidth field 808 is configured independently of the DTC field 804, etc., the value of 0 in the DSO Subbandwidth field may be associated with 20MHz of DSO Subbandwidth. In this case, the DSO Subbandwidth corresponding to each value in the DSO Subbandwidth field is incremented. For example, a value of 1 in the DSO Subbandwidth field is associated with 40MHz in the DSO Subbandwidth.

[0060] Table 3

[0061] The DSO Padding Timeout field 809 indicates the allowable time for the frequency switching delay of STA 110 when AP 101 performs DSO. For example, the DSO Padding Timeout field 809 may indicate the allowable time for the first frequency switching delay required for STA 110 to move from one frequency domain to another. An example configuration of the DSO Padding Timeout field 809 is shown in Table 4. Table 4 shows the values ​​set in the DSO Padding Timeout field 809 and the time corresponding to those values ​​when the DSO Padding Timeout field 809 is configured with 4 bits. For example, if the UHR Capabilities element received from AP101 contains a DSO Padding Timeout field 809, STA110 can determine the allowable time for the first frequency switching delay based on Table 4. If the allowable time for the first frequency switching delay differs depending on the distance STA110 moves along the frequency axis, DSO Padding Timeout fields 809 corresponding to each distance may be provided.

[0062] Table 4

[0063] The DSO Transition Timeout field 810 indicates the allowable time for the frequency switching delay of STA 110 when AP 101 performs DSO. For example, the DSO Transition Timeout field 810 may indicate the allowable time for a second frequency switching delay required for STA 110 to move from another frequency domain to the first frequency domain. The DSO Transition Timeout field 810, like the DSO Padding Timeout field 809, may be configured as shown in Table 4, for example.

[0064] Note that the mapping of values ​​in Tables 1 to 4 above is just an example, and the mappings can be different. For example, Tables 1 to 4 show an example where the corresponding value increases exponentially for each increase of 1 in the field value, but the corresponding value can be set to increase by the same amount for each increase of 1 in the field value. For example, in Table 1, the value of the DSO Padding Delay field 806 may increase by 16 μsec each time. Also, in Tables 1, 2, and 4, different values ​​are mapped to the same value set in the field, but the same value may be mapped. For example, when the value of the DSO Padding Delay field in Table 1 is 1, 16 μsec may be mapped, similar to when the value of the DSO Padding Delay field in Table 2 is 1. Furthermore, Tables 1 to 3 show an example where each field consists of 3 bits, but each field may consist of 1, 2, 4 or more bits. Similarly, Table 4 shows an example where the field consists of 4 bits, but the field may consist of 1 to 3, 5 or more bits. Also, the DSO Paddin Delay field 806 and the DSO Transition Delay field 807 may be configured as a single field. Similarly, the DSO Paddin Timeout field 808 and the DSO Transition Timeout field 810 may be configured as a single field. For example, if the first frequency switching delay and the second frequency switching delay are of similar magnitude, configuring these fields as a single field can reduce the amount of information communicated.

[0065] Fields other than those included in Figure 8 may be included in the UHR Capabilities element. For example, a predetermined field may be included that indicates information for identifying each frequency domain to be set in the frequency band used by AP101. For example, STA110 may use this predetermined field to notify AP101 of information indicating the number of frequency domains to be set in the frequency band used by AP, or information indicating the number of frequency switching positions. For example, if the number of frequency domains is indicated by this predetermined field, the same number of frequency domains with the same bandwidth as the bandwidth usable by STA110 may be set. Also, if the number of frequency domains is indicated by this predetermined field, the number of frequency domains indicated by this predetermined field may be set in the frequency band used by AP101. In this case, the bandwidth of each frequency domain can be determined by dividing the bandwidth of the frequency band used by AP101 by the number of frequency domains to be set. Also, if the number of frequency switching positions is indicated by this predetermined field, the number of frequency switching positions indicated by this predetermined field may be set for each bandwidth usable by STA110 in the frequency band used by AP101. Furthermore, if the number of frequency switching positions is indicated by this predetermined field, each frequency switching position can be set at a position on the frequency axis obtained by dividing the frequency band used by AP101 by the number indicated by this predetermined field. AP101 can determine multiple frequency ranges and frequency switching positions to be set in the frequency band used by its device based on the value of the predetermined field included in the frame received from STA110. AP101 can then notify STA110 of the result in the predetermined field in the frame transmitted by its device. AP101 may also unilaterally determine multiple frequency ranges and frequency switching positions to be set in the frequency band used by its device and notify STA110 of them.

[0066] Figure 8 shows an example in which the communication device 100 uses the UHR Capabilities element to notify the other communication device of its ability to perform DSO. However, this notification of capability information can be performed using other information elements. For example, the Extended Capabilities element can be used to extend the UHR Capabilities element, or the Multi-Link element can be used to notify information related to multilink communication. In addition, a new element (such as a DSO element) may be defined for exchanging capability information related to the communication device's DSO. The communication device 100 may also add its ability to perform DSO to the UHR Operation element. This allows the communication device 100 to display a value corresponding to the change even when its ability to perform DSO is dynamically changed.

[0067] (Downlink Data Communication Processing between AP and STA) The operation when data communication is performed using DSO between AP101 and STA110 will be explained. Figure 9 shows an example sequence when downlink communication (downlink communication) is performed when AP101 sends data to STA110. OFDMA is used in this communication. For example, AP101 transmits data using UHR MU PPDU, which corresponds to OFDMA. UHR MU PPDU is an abbreviation for Ultra High Reliability Multi-user PPDU. In this example, AP101 and STA111 are in a state where they can perform communication using DSO, while STA112 is in a state where it cannot perform communication using DSO. In the connection between AP101 and STA111, it is assumed that two frequency domains for performing DSO are set in the frequency band used by AP101. For example, suppose AP101 uses a frequency band with a bandwidth of 320 MHz, STA111 can use a bandwidth up to 80 MHz, and the first and second frequency domains each have a bandwidth of 160 MHz. In this case, STA111 can communicate with AP101 while moving between the 80 MHz bandwidth frequency band included in the first frequency domain and the 80 MHz bandwidth frequency band included in the second frequency domain. Alternatively, instead of explicitly setting two frequency domains, two frequency domains with a bandwidth of 160 MHz may be implicitly set by providing a single frequency switching position. Note that in the connection between AP101 and STA112, no setting of frequency domains or frequency switching positions is performed. AP101 also stores data destined for each STA110. AP101 shall allocate a first frequency domain frequency resource to STA112, which cannot use DSO, and a second frequency domain frequency resource to STA111, which can perform DSO, in order to transmit this data.

[0068] First, AP101 sends a notification 901 to move STA111 to a second frequency domain prior to transmitting data. For example, AP101 may send a MU-RTS frame as notification 901. A MU-RTS frame is a type of Trigger frame, and MU-RTS is an abbreviation for multi-user request to send. For example, AP101 sends a MU-RTS frame in the first frequency domain, which includes the PCH. This allows any STA110 connected to AP101 to receive the MU-RTS frame, regardless of whether DSO is performed. The MU-RTS frame may include User Info fields corresponding to STA111 and STA112, respectively. The User Info field of the MU-RTS frame may contain information indicating the channel on which the corresponding STA110 should send a response. Furthermore, the User Info field of the MU-RTS frame may contain information indicating the frequency resources allocated to the corresponding STA 110. This allows the STA 110 to identify the frequency resources allocated to its device and the frequency domain containing those resources before it begins receiving the PPDU. For example, AP 101 may instruct STA 111 to move to the second frequency domain by notifying it of information indicating that frequency resources in the second frequency domain have been allocated using the User Info field corresponding to STA 111. AP 101 may also add padding 902 to the frame used for notification 901. The padding 902 may be added based on a first frequency switching delay for STA 111 to move to the second frequency domain.

[0069] When STA111 receives notification 901, it moves to the second frequency domain on the frequency axis. For example, if notification 901 is a MU-RTS frame, STA111 identifies from the User Info field associated with its own device that a frequency resource in the second frequency domain has been allocated to its own device, and determines that it should move to the second frequency domain. STA111 then sends a response 904 to notification 901 in the second frequency domain. For example, if notification 901 is a MU-RTS frame, STA111 sends a CTS frame as the response 904. CTS is an abbreviation for clear to send. STA111 may also send a CTS frame if the time elapsed from the start of movement to the second frequency domain to the transmission of the CTS frame is less than or equal to the allowable time notified by AP101. In this case, once STA111 has finished receiving the User Info field associated with its own device, it starts moving to the second frequency domain and activates timer 903. Timer 903 can be set to expire within the allowable time notified by AP101. When STA111 transmits a CTS frame, it transmits the CTS frame if timer 903 has not expired, and does not transmit the CTS frame if timer 903 has expired. This prevents STA111 from transmitting a CTS frame at a time exceeding the allowable time set by AP101.

[0070] When STA112 receives notification 901, it makes a response 905 in the first frequency domain. For example, if notification 901 is a MU-RTS frame, STA112 sends a CTS frame as the response 905.

[0071] When AP101 receives a response 904 or response 905 to notification 901, it transmits data based on the received response. For example, based on receiving response 904 from STA111 in the second frequency domain, AP101 transmits data 906 in the second frequency domain. Also, based on receiving response 905 from STA112 in the first frequency domain, AP101 transmits data 907 in the first frequency domain. Note that if AP101 does not receive a response to notification 901, it does not transmit data. For example, if AP101 receives response 905 but not response 904, it transmits data 907 instead of data 906.

[0072] When STA111 and STA112 receive data 906 and 907 addressed to their respective devices, they each send acknowledgments 908 and 909 for that data. For example, STA111 and STA112 may each send Block Ack frames as acknowledgments 908 and 909. STA111 and STA112 send Block Ack frames in the second frequency domain and the first frequency domain, respectively. After sending acknowledgment 908, STA111 may move to the first frequency domain. This allows STA111 to respond to subsequent communications taking place in the first frequency domain, including the PCH.

[0073] (Processing performed by AP when performing downlink communication) An example of the processing flow performed by AP101 when performing downlink communication will be explained using Figure 10. Figure 10 is, for example, the processing flow performed by AP101 when performing downlink communication in Figure 9. This processing flow may be started when data destined for STA110 is accumulated in AP101's transmit buffer. In this example, AP101 is assumed to have accumulated multiple data destined for STA111 and STA112, respectively. First, AP101 allocates frequency resources to each STA110 based on the fact that multiple data destined for STA111 and STA112, respectively, have been accumulated in its device (S1001). For example, AP101 may allocate frequency resources based on whether each STA110 is in a state where it can perform DSO. The state where DSO can be performed may be a state in which STA110 has the function to perform DSO and has enabled the function to perform DSO. A state in which DSO cannot be executed may be a state in which STA110 does not have the function to execute DSO or has disabled the function to execute DSO. For example, AP101 may allocate a frequency resource in a first frequency domain including the PCH to STA112 based on the fact that STA112 is in a state in which DSO cannot be executed. Also, AP101 may allocate a frequency resource in a first frequency domain including the PCH or a frequency resource in a second frequency domain not including the PCH to STA111 based on the fact that STA111 is in a state in which DSO can be executed. In this example, let's assume that AP101 allocates a frequency resource in the first frequency domain to STA112, which is in a state in which DSO cannot be executed, and allocates a frequency resource in the second frequency domain to STA111, which is in a state in which DSO can be executed. Note that if there are three or more frequency domains set between AP101 and STA111, AP101 may select any one of the frequency domains to allocate the frequency resource. For example, if the frequency switching delay of AP101 differs depending on the distance STA111 moves along the frequency axis, AP101 may prioritize selecting a frequency range where the frequency switching delay of STA111 is small (e.g., where the movement distance is small).By reducing the frequency switching delay, the AP is more likely to complete its movement along the frequency axis and perform DSO within an acceptable time, allowing it to reduce the size of the padding that AP 101 adds to the frame. Furthermore, if AP 101 can obtain information from STA 111 indicating interference in each frequency domain, it may prioritize selecting a frequency domain with less interference. Also, if AP 101 has two or more STA 110 capable of performing DSO connected to its device, it can allocate frequency resources in frequency domains other than the first frequency domain including the PCH to multiple STA 110s. In this case, AP 101 can allocate frequency resources such that STA 110s that can use frequency domains further from the PCH are allocated frequency resources in more distant frequency domains. This can increase the number of STA 110s that can communicate in parallel, allowing AP 101 to use the available frequency band more efficiently.

[0074] If AP101 allocates a frequency resource in the first frequency domain, including the PCH, to either STA111 or STA112 (NO in S1002), it uses the allocated frequency resource to transmit to each STA110 (S1003). For example, AP101 can transmit data to each STA110 in parallel by using a UHR MU PPDU that supports OFDMA communication. In this case, AP101 can transmit a PPDU containing data without transmitting a MU-RTS frame or receiving a CTS frame. AP101 can also notify each STA of the frequency resource allocated to them using the UHR SIG field in the preamble of the UHR MU PPDU.

[0075] On the other hand, if AP101 allocates a frequency resource in the second frequency domain to at least one of STA111 and STA112 (YES in S1002), it instructs them to move to the second frequency domain (S1004). For example, in this example, AP101 may instruct STA111 to move to the second frequency domain using a MU-RTS frame. In this case, as will be described later, AP101 may notify each of STA110 of the frequency resources allocated to them using the PS160 subfield and the RU Allocation subfield of the User Info field included in the MU-RTS. STA110 may determine that it should move to the second frequency domain based on the fact that the allocated RU is included in the second frequency domain. AP101 may use some of these subfields to notify information that identifies the frequency domain containing the frequency resources allocated to STA110, and may also notify information that identifies the frequency resources in the subsequent PPDU containing the data. For example, AP101 may use the PS160 subfield and the B0 bit of the RU Allocation subfield to notify the frequency domain containing the frequency resources allocated to STA110. AP101 may also use other frames to instruct STA110 to move to another frequency domain. For example, if a new type of frame is defined to indicate that STA110 should move to another frequency domain, AP101 may use this frame to give instructions. In this case, after STA110 sends a frame instructing it to move to another frequency domain, it may request that each STA110 send a CTS frame by sending MU-RTS frames or RTS frames in their respective frequency domains. In this case, AP101 can confirm that the STA110 has completed its movement across the frequency domain by receiving MU-RTS frames and CTS frames corresponding to RTS frames in their respective frequency domains.

[0076] Furthermore, when AP101 notifies STA110 that it should switch to a second frequency domain, it may adjust the frame size to take into account the time required for STA111 to switch the frequency band it will be using. In a normal exchange of MU-RTS frames and CTS frames, communication device 100 receives a MU-RTS frame and transmits a CTS frame after SIFS. However, when STA110 moves along the frequency axis, it may not be able to transmit a CTS frame in the destination frequency domain after SIFS following the reception of the MU-RTS frame. In response to this, AP101 may adjust the frame size to take into account the frequency switching delay of STA110 when notifying STA110 that it should switch to a second frequency domain. For example, AP101 may add predetermined padding to the MU-RTS frame. As an example, AP101 may add padding such that the time from the completion of transmission of the User Info field corresponding to STA110 to the completion of transmission of the MU-RTS frame is longer than the frequency switching delay of STA110. This allows STA110 to complete transmission of the MU-RTS frame and transmit the CTS frame after SIFS, even if it starts shifting frequencies after completing reception of the User Info field corresponding to its own device. AP101 may also place User Info corresponding to STA110 with a large frequency switching delay near the beginning of the MU-RTS frame. This allows STA110 to shift frequencies while User Info fields for STA110 other than its own device are being transmitted.

[0077] If AP101 notifies STA110 that it should move to the second frequency domain, it waits for a response for a predetermined period (S1005). For example, after transmitting a MU-RTS frame, AP101 waits for a predetermined period to receive a CTS frame. The predetermined period may be SIFS or longer than SIFS. If AP101 receives CTS frames from all STA110 that were the destinations for the MU-RTS frame (YES in S1005), AP101 transmits data to each STA110 using the frequency resources allocated in S1001 (S1006). On the other hand, if AP101 does not receive a CTS frame from one or more of the STA110 that were the destinations for the MU-RTS frame (NO in S1005), it transmits data to the STA110 that sent the received CTS frame (S1007). In this case, AP101 does not send data to STA110, which has not been confirmed to have sent a CTS frame for the MU-RTS frame.

[0078] AP101 transmits data in parallel to multiple STA110s using an OFDMA-compatible UHR MU PPDU. In this case, AP101 may notify each STA110 of the RU assigned to it in the preamble of the UHR MU PPDU. When AP101 receives an acknowledgment from the STA110 that sent the data, it terminates the transmission process. AP101 may also refrain from the next communication for a period of time equivalent to the frequency switching delay required for an STA111 that has moved to the second frequency domain to move back to the first frequency domain.

[0079] (Processing performed by STA when performing downlink communication) Next, an example of the processing flow performed by STA110 when performing downlink communication will be explained using Figure 11. Figure 11 is, for example, the processing flow performed by STA111 in Figure 9 when performing downlink communication. First, STA110 receives a frame in the PCH of the first frequency domain (S1101). STA110 determines whether the received frame contains an instruction for its own device to move to the second frequency domain (S1102). For example, if the received frame is a MU-RTS frame, STA110 can identify the frequency resource allocated to its own device in the User Info field corresponding to its own device. If the identified frequency resource is a frequency resource included in the second frequency domain, STA110 can determine that it should move to the second frequency domain. Furthermore, if the received frame contains information indicating that frequency resources included in the second frequency domain have been allocated to the device, the STA 110 may determine, based on this information, that it should move to the second frequency domain. Also, if the received frame contains an instruction that the device should move to the second frequency domain, the STA 110 may determine, based on this instruction, that it should move to the second frequency domain.

[0080] If STA110 determines, based on the received frame, that it should move to a second frequency domain (YES in S1102), it moves to the second frequency domain (S1103). For example, if STA110 determines that it should move to a second frequency domain based on information obtained from the User Info field corresponding to its own device in the MU-RTS frame, it may start moving as soon as it has finished receiving the User Info field. In this case, if STA110 completes the move to the second frequency domain before the timer started at the start of the move expires (S1104), it transmits a CTS frame in the second frequency domain as a response to the MU-RTS frame (S1105). STA110 waits for data from AP101 in the second frequency domain. On the other hand, if STA110 does not complete the transition to the second frequency domain before the timer expires (NO in S1104), it returns to the first frequency domain without responding to the MU-RTS frame and completes the process.

[0081] On the other hand, if STA110 does not determine that it should move to the second frequency domain (NO in S1102), it continues to communicate in the first frequency domain. For example, if the received frame is a MU-RTS frame, STA110 sends a response after SIFS from the completion of reception (S1105) and waits for data from AP101.

[0082] STA110 receives data from AP101 (S1106). For example, STA110 receives a UHR MU PPDU corresponding to OFDMA and retrieves data addressed to itself contained in the received PPDU. In this case, the RU allocated for the data addressed to STA110 may be indicated in the PPDU preamble. STA110 sends an acknowledgment in the frequency domain containing the RU that received the data. If STA110 moves to the second frequency domain, it sends an acknowledgment and then moves to the first frequency domain.

[0083] (Uplink data communication processing between AP and STA) Figure 12 shows an example sequence when uplink communication (uplink communication) is performed in which STA 110 transmits data to AP 101. OFDMA is used in this communication. For example, each STA 110 transmits data using a UHR TB PPDU corresponding to OFDMA. UHR TB PPDU is an abbreviation for Ultra High Reliability Trigger-based PPDU. In this example, AP 101 and STA 111 are in a state where they can perform communication using DSO, while STA 112 is in a state where it cannot perform communication using DSO. Also, in this example, as in Figure 9, it is assumed that in the connection between AP 101 and STA 111, two 160 MHz bandwidth frequency domains are set for performing DSO in the frequency band used by AP 101. Assume that STA111 and STA112 are storing data, and AP101 is obtaining information that each of STA110 is storing data. In order to transmit this data, AP101 will allocate a frequency resource in the first frequency domain to STA112, which cannot use DSO, and a frequency resource in the second frequency domain to STA111, which can perform DSO.

[0084] First, AP101 sends a notification 1201 to move STA111 to a second frequency domain prior to data transmission by STA110. For example, AP101 may send a Trigger frame as notification 1201. This Trigger frame may be a Basic type Trigger frame. AP101 sends the Trigger frame in the first frequency domain, including the PCH, so that both STA111 and STA112 can receive it. The Trigger frame may include User Info fields corresponding to STA111 and STA112, respectively. The User Info fields may include information indicating the frequency resources allocated to the corresponding STA110. For example, AP101 can implicitly instruct STA111 to move to the second frequency domain by notifying it of information indicating the allocation of frequency resources in the second frequency domain using the User Info field corresponding to STA111. AP101 can also notify each of the frequency resources (RUs) allocated to each of STA110 using the User Info field corresponding to each of STA110. This allows AP101 to instruct STA111 to move to the second frequency domain and to notify each of the frequency resources allocated to each of STA110 in a single notification. AP101 may notify STA111 to move to the second frequency domain and notify each of the frequency resources allocated to each of STA110 using different information or different frames. For example, a new field for instructing a move to a frequency domain may be defined in the Trigger frame, or a new frame for instructing a move to a frequency domain may be defined. This allows AP101 to explicitly notify STA111 that it should move to the second frequency domain. AP101 may add padding 1202 to the frame used for notification 1201. The padding 1202 may be added based on the frequency switching delay required for STA111 to move to the second frequency domain.

[0085] When STA111 receives notification 1201, it moves to the second frequency domain. For example, if notification 1201 is a Basic type Trigger frame, STA111 can determine from the information contained in the User Info field associated with its own device that frequency resources in the second frequency domain have been allocated to its own device. In this case, STA111 can determine that it should move to the second frequency domain based on the fact that frequency resources in the second frequency domain have been allocated to its own device. After moving to the second frequency domain, STA111 transmits data 1204 using the frequency resources allocated to its own device. STA111 may also transmit data 1204 if the time taken from the start of the move to the second frequency domain until it is ready to transmit data is less than or equal to the allowable time notified by AP101. In this case, when STA111 has finished receiving the User Info field associated with its own device, it starts the move to the second frequency domain and activates timer 1203. Timer 1203 can be set to expire within the allowable time notified by AP 101. When STA 111 transmits data 1204, it transmits data 1204 if Timer 1203 has not expired, and does not transmit data 1204 if Timer 1203 has expired. This prevents STA 111 from transmitting data 1204 at a time exceeding the allowable time set by AP 101.

[0086] When STA112 receives notification 1201, it transmits data 1205 in the first frequency domain. For example, if notification 1201 is a Basic type Trigger frame, STA112 transmits data 1205 using the frequency resources allocated in the User Info field corresponding to its own device in the Trigger frame.

[0087] When AP101 receives data from each of the STA110 devices, it sends an acknowledgment. For example, AP101 can send an acknowledgment by transmitting a Block Ack frame. AP101 sends a Block Ack frame 1206 in the second frequency domain for data 1204 received from STA111 in the second frequency domain. AP101 also sends a Block Ack frame 1207 in the first frequency domain for data 1205 received from STA112 in the first frequency domain. STA110 completes its transmission process upon receiving an acknowledgment for the data it has transmitted. After STA111 has finished receiving the Block Ack 1206 for data 1204, it moves to the first frequency domain.

[0088] (Processing performed by AP when performing uplink communication) An example of the processing flow performed by AP101 when performing uplink communication will be explained using Figure 13. Figure 13 is, for example, the processing flow performed by AP101 when performing uplink communication in Figure 12. This processing flow may be started when AP101 detects that data is being stored in STA110. AP101 may obtain information from each of the STA110 to identify the data storage status in order to determine whether or not there is data stored in each of the STA110. For example, AP101 may inquire about the presence or absence of data stored in STA110 by sending a Buffer Status Report Polling (BSRP) frame to STA110. When STA110 receives the BSRP frame, it may notify AP101 of the Buffer Status Report. In this way, AP101 can obtain the data accumulation status in each of STA110.

[0089] AP101 allocates frequency resources to each of the one or more STA110s that are storing data (S1301). For example, AP101 may allocate frequency resources based on whether each STA110 is in a state where it can perform DSO, similar to S1001 in Figure 10. In this example, AP101 allocates frequency resources in the first frequency domain to STA112, which is in a state where it cannot perform DSO, and allocates frequency resources in the second frequency domain to STA111, which is in a state where it can perform DSO.

[0090] If AP101 allocates a frequency resource in the first frequency domain, including the PCH, to either STA111 or STA112 (NO in S1302), it notifies that no frequency resources in the second frequency domain have been allocated (S1303). For example, AP101 may notify by sending a Basic-type Trigger frame containing information indicating the first frequency domain frequency resources allocated to each of STA110. On the other hand, if AP101 allocates a frequency resource in the second frequency domain to one or more of STA110 (YES in S1302), it notifies that a frequency resource in the second frequency domain has been allocated (S1304). By notifying that a frequency resource in the second frequency domain has been allocated, AP101 can implicitly instruct STA110 to move to the second frequency domain. Alternatively, AP101 may notify STA110 of information explicitly instructing it to move to the second frequency domain. For example, AP101 may transmit a Basic-type Trigger frame containing information indicating a second frequency domain frequency resource allocated to STA110. In this case, AP101 may notify STA110 of the allocated RU using the PS160 subfield and the RU Allocation subfield of the User Info field corresponding to each STA110 included in the Trigger frame. Based on the fact that the allocated RU is included in the second frequency domain, STA110 may determine that it should move to the second frequency domain. AP101 may also adjust the frame size in the notification indicating that a second frequency domain frequency resource has been allocated, similar to S1004 in Figure 10.

[0091] AP101 receives data from each of the STA110 (S1305). For example, AP101 may receive UHR TB PPDUs from each of the STA110 that are transmitted using the frequency resources allocated to each of the STA110. AP101 then performs an acknowledgment of the received data and terminates the reception process. For example, if AP101 does not allocate frequency resources in the second frequency domain, it may perform an acknowledgment by transmitting a Multi-STA Block ACK in the first frequency domain. A Multi-STA Block ACK is a frame used to perform acknowledgments to multiple STAs using a single frame. Alternatively, if AP101 allocates frequency resources in the second frequency domain to STA111 and frequency resources in the first frequency domain to STA112, it may transmit a Block ACK in each frequency domain. For example, AP101 may transmit a Block ACK acknowledgment in the first frequency domain for data received from STA112, and transmit a Block ACK acknowledgment in the second frequency domain for data received from STA111. Furthermore, when AP101 allocates frequency resources in the second frequency domain to STA111, it may add padding to the Block ACK frame, similar to the notification in S1304 indicating that frequency resources in the second frequency domain have been allocated. In this case, AP101 may add padding to the Block ACKs transmitted in each frequency domain. This prevents the next communication from being executed until STA111 becomes ready to communicate in the first frequency domain.

[0092] (Processing performed by STA when performing uplink communication) Next, an example of the processing flow performed by STA110 when performing uplink communication will be explained using Figure 14. Figure 14 is, for example, the processing flow performed by STA111 in Figure 12 when performing uplink communication. First, STA110 receives a frame in the PCH of the first frequency domain (S1401). STA110 determines whether the received frame contains an instruction indicating that its own device should move to the second frequency domain (S1402). For example, if the received frame is a Basic type Trigger frame, STA110 can identify the frequency resource allocated to its own device in the User Info field corresponding to its own device. If the identified frequency resource is a frequency resource included in the second frequency domain, STA110 can determine that it should move to the second frequency domain.

[0093] If STA110 determines, based on the received frame, that it should move to a second frequency domain (YES in S1402), it moves to the second frequency domain (S1403). For example, if STA110 determines that it should move to a second frequency domain based on information obtained from the User Info field corresponding to its own device in the Trigger frame, it may start moving as soon as it has finished receiving the User Info field. In this case, if STA110 completes the move to the second frequency domain before the timer started at the start of the move expires (S1404), it transmits data in the second frequency domain using the frequency resources allocated to its own device (S1405). For example, STA110 transmits a UHR TB PPDU using the RU allocated to its own device by the Trigger frame. On the other hand, if STA110 does not complete the transition to the second frequency domain before the timer expires (NO in S1404), it returns to the first frequency domain without transmitting data and completes the process.

[0094] On the other hand, if STA110 does not determine that it should move to the second frequency domain (NO in S1402), it continues to communicate in the first frequency domain. For example, if the received frame is a Trigger frame, STA110 transmits data using the frequency resources allocated to its own device (S1405).

[0095] (Configuration of information used for data communication between AP and STA) The configuration of information used by AP 101 when notifying STA 110 of the frequency resources allocated to it will be described. Figure 15 shows an example of the configuration of the User Info field included in the Trigger frame used by AP 101 when notifying STA 110 of the frequency resources allocated to it. The Trigger frame may include one or more User Info fields corresponding to one or more destination STA 110s. The User Info field shown in Figure 15 may be included in a Basic type Trigger frame or a MU-RTS frame. In addition, the User Info field shown in Figure 15 may be included in a new frame defined by AP 101 to cause STA 110 to move in the frequency domain. The User Info field in Figure 15 may consist of an AID 12 subfield 1501, a RU Allocation subfield 1502, and a PS160 subfield 1503. The AID 12 subfield 1501 indicates information for identifying the STA 110 corresponding to this User Info field. For example, the AID 12 subfield indicates 12 digits of the AID of the STA 110 assigned by AP 101 when establishing a connection with the STA 110. AID is an abbreviation for Association ID. The STA 110 can determine whether a User Info field corresponds to its own device based on whether the value of the AID 12 subfield contained in each User Info field matches 12 digits of its own device's AID. The RU Allocation field 1502 and the PS160 field 1503 are specific information for uniquely identifying the frequency resource allocated to the STA110 corresponding to this User Info field.

[0096] An example of the correspondence between the values ​​of the RU Allocation field 1502 and the PS160 field 1503 and frequency resources (RUs) is explained using Figure 16. In Figure 16, PS160 represents the value of the PS160 field 1503. B0 represents the value of the 0th bit of the RU Allocation field 1502. B7-B1 represent the decimal values ​​indicated by the 7th to 1st bits of the RU Allocation field 1502, and each value corresponds to the RU indicated by the RU index. For example, if the values ​​of B7-B1 are 0, it indicates that a 26-tone RU with RU index RU1 is allocated. RU or MRU size indicates the size of the allocated RU, from 26-tone RUs to 996-tone RUs. Bandwidth corresponds to the total frequency bandwidth used by AP101. RU index indicates the range of RU indices that AP101 can assign to STA110. For example, RU indices 1-9 can be assigned to STA110 when the bandwidth used by AP101 is between 20 MHz and 320 MHz. On the other hand, RU indices 10-37 cannot be assigned to STA110 when the bandwidth used by AP101 is 20 MHz. This is because, as shown in Figure 17, RU indexes 10-37 are assigned when the frequency bandwidth exceeds 20 MHz. Here, we assume that the available frequency bandwidth for STA110 is 20 MHz, DSO cannot be used, and PCH is 20 MHz, corresponding to RU indexes 1-9 shown in Figure 17. In this case, a 26-tone RU in the range of RU index 1-9 may be assigned to this STA 110. Similarly, a 52-tone RU in the range of RU index 1-4, a 106-tone RU in the range of RU index 1-2, and a 242-tone RU in RU index 1 may be assigned to this STA 110. On the other hand, a DSO-capable STA 110 can expand its usable frequency band by moving along the frequency axis in the frequency band used by AP 101.The travel distance that STA110 can move on the frequency axis is indicated by the aforementioned DSO Subbandwidth field 808. This increases the number of RUs that can be assigned to STA110. For example, if the bandwidth used by STA110 is 20 MHz and the travel distance is 20 MHz, STA110 can use a bandwidth equivalent to 40 MHz due to the DSO. Therefore, STA110 can be assigned 26-tone RUs in the range of RU index 1-18. Similarly, such STA110 can be assigned 52-tone RUs in the range of RU index 1-8, 106-tone RUs in the range of RU index 1-4, and 242-tone RUs in the range of RU index 1-2. Furthermore, for example, if the mobile range of STA110 is 60 MHz, STA110 that can use a bandwidth equivalent to 80 MHz due to DSO may be assigned a 26-tone RU in the range of RU index 1-37. Similarly, this STA110 may be assigned a 52-tone RU in the range of RU index 1-16, a 106-tone RU in the range of RU index 1-4, and a 242-tone RU in the range of RU index 1-4.

[0097] If the frequency bandwidth used by AP101 in OFDMA exceeds 80 MHz, the allocation of RUs is notified by a combination of the 80 MHz bandwidth subblocks indicated by PS160 and B0 and the RU index. For example, if AP101 uses a PPDU with a frequency bandwidth of 320 MHz to communicate via OFDMA, four 80 MHz bandwidth subblocks are set. In Figure 16, each of the 2 bits indicated by PS160 and B0, values ​​from 0 to 3, corresponds to the first to fourth subblocks. STA110 can identify the subblock containing the frequency resources allocated to its device from the values ​​indicated by PS160 and B0, and identify the RUs allocated to its device from the values ​​indicated by B7-B1.

[0098] AP101 can use the frequency resource allocation information configured as described above to notify STA110 that it should move to a different frequency domain. For example, if the bandwidths of each frequency domain set with STA110 are 160 MHz, AP101 can use the value of PS160 to notify STA110 that it should move to a different frequency domain. For example, by setting the value of PS160 to 1, AP101 can notify STA110 that it should move to a second frequency domain. For example, if the bandwidths of each frequency domain set with STA110 are 80 MHz, AP101 can use the value of PS160 and the value of B0 to notify STA110 that it should move to a different frequency domain. For example, by using the value of PS160 and the value of B0 to notify STA110 of a value between 1 and 3, AP101 can notify STA110 that it should move to a second to fourth frequency domain. Furthermore, if the respective bandwidths of the frequency domains set with STA110 are 20 MHz or 40 MHz, AP101 may notify STA110 that it should move to a different frequency domain using the values ​​of PS160, B0, and B7-B1. For example, AP101 may notify STA110 that frequency resources have been allocated to the second to fourth subblocks by notifying values ​​1 to 3 using the values ​​of PS160 and B0. Then, AP101 may notify STA110 of the frequency domain to which it should move by notifying it of the RU allocated to it using the values ​​of B7-B1. For example, suppose AP101 sends a frame containing the RU Allocation subfield with B7-B1 values ​​set to 9 to STA110, which has an available bandwidth of 20 MHz and can use a bandwidth equivalent to 40 MHz. In this case, STA110 can determine that a frequency resource in a second frequency domain with a bandwidth of 20 MHz has been allocated to its device. As a result, STA110 can determine that it should move to the second frequency domain. AP101 can also notify STA110 of the destination frequency domain using the value of PS160, the value of B0, and a newly established field, if the respective bandwidths of the frequency domains set between AP101 and STA110 are 20 MHz or 40 MHz.For example, if the bandwidths of the frequency domains set between AP101 and STA110 are 40 MHz, AP101 notifies STA110 of the subblock to which it should move based on the values ​​of PS160 and B0. AP101 can then use a newly added bit to notify whether it should move to the lower 40 MHz frequency domain or the upper 40 MHz frequency domain within the 80 MHz bandwidth subblock. Similarly, if the bandwidths of the frequency domains set between AP101 and STA110 are 20 MHz, AP101 notifies STA110 of the subblock to which it should move based on the values ​​of PS160 and B0. AP101 can then use two newly added bits to notify whether it should move to the first to fourth 20 MHz frequency domains within the 80 MHz bandwidth subblock.

[0099] Furthermore, when AP101 notifies STA110 to move frequency domains using an MU-RTS frame during downlink communication, it can use this MU-RTS frame to notify multiple types of information at once. For example, AP101 can use an MU-RTS frame to notify STA110 at once whether or not to move frequency domains, the frequency resources allocated to STA110, and the channel on which STA110 should transmit CTS frames. As an example, AP101 can use the PS160 value, the B0 value, and the B7-B1 values ​​of the MU-RTS frame to notify STA110 of the frequency resources allocated to it. In this case, by using a value of 60 or less for the B7-B1 values, AP101 can notify the allocation of an RU with a bandwidth smaller than 20 MHz, as shown in Figure 16. Furthermore, AP101 can implicitly notify STA110 that it should move to a different frequency domain by indicating that the frequency domain containing the frequency resource allocated to STA110 does not include a PCH. AP101 can also notify STA110 that it should transmit a CTS frame on a 20MHz channel containing a RU by notifying STA110 of the RU allocated to STA110. Based on the received MU-RTS frame, STA110 can identify the frequency domain to move to, the channel on which to transmit the CTS frame, and the RU on which to receive the data.

[0100] Figure 16 illustrates the frequency resource allocation when AP101 assigns one RU to STA110. Even when AP101 assigns multiple RUs to STA110, similar operation is possible based on the MRU allocation specified in the IEEE 802.11be standard. MRU stands for Multiple Resource Unit. For example, if STA110 has a usable bandwidth of 20 MHz and can use a bandwidth equivalent to 80 MHz by performing DSO, setting B7-B1 to a value of 75 may indicate an RU allocation of 52-tone + 26-tone MRU index 6. In this case, AP101 can implicitly notify STA110 to move to a second frequency domain with a bandwidth of 20 MHz.

[0101] As described above, according to this embodiment, AP101 acquires capability information indicating whether STA110 has the capability to perform communication using DSO, and selects a frequency range that includes the frequency resources to be allocated based on the capability information of STA110. STA110 moves to the frequency range that includes the frequency resources allocated to its device and performs communication with AP101. With this configuration, AP101 can perform communication using OFDMA using a wider bandwidth than the corresponding bandwidths of each STA110 connected to its device, even if those bandwidths are narrow. This allows AP101 to utilize unused frequency bands within its available frequency range, thereby improving frequency utilization efficiency. In this embodiment, the DSO Padding delay field 806 to the DSO sub bandwidth field 808 were described using an example where they are included in a Probe Request frame, etc. Similarly, an example was given using a Probe Response frame, etc., in which the DSO Padding Timeout field 809 and the DSO Transaction Timeout field 810 are included. These fields may also be included in other frames. For example, the communication device 100 may include these fields in a Public Action frame or a Protected Public Action frame. Public Action frames and Protected Public Action frames can be used to indicate that the DSO function has been enabled or disabled. That is, the communication device 100 may notify communication parameters for executing the DSO function along with information indicating that the state of the DSO function in its device has changed. In this case, AP101 can switch whether to enable or disable the DSO function for each STA110 based on the notification from STA110.

[0102] In this embodiment, the operation of communicating using a frequency domain that does not include the PCH is exemplified as DSO, but it is not limited to this and may be referred to by other names. In this embodiment, the frequency domain that includes the PCH is exemplified as the first frequency domain, and the frequency domain that does not include the PCH is exemplified as the second frequency domain, etc., but it is not limited to this and may be referred to by other names. Also, the parameters referred to as frequency switching delay, frequency switching position, etc. in this embodiment may be referred to by other names. Similarly, the fields and subfields included in the configuration examples in Figures 8 and 15 may be referred to by other names. The setting values ​​and corresponding values ​​of the information shown in Figure 16 and Tables 1 to 4 may be configured to be different.

[0103] This disclosure can also be implemented by supplying a program that implements one or more of the functions of the embodiments described above to a system or device via a network or storage medium, and by having one or more processors in the computer of that system or device read and execute the program. It can also be implemented by a circuit (e.g., ASIC) that implements one or more of the functions. (Other embodiments) This disclosure can also be implemented by supplying a program that implements one or more of the functions of the embodiments described above to a system or device via a network or storage medium, and by having one or more processors in the computer of that system or device read and execute the program. It can also be implemented by a circuit (e.g., ASIC) that implements one or more of the functions.

[0104] The technical ideas derived from this disclosure are not limited to the exemplary embodiments disclosed, but are intended to encompass various modifications of the exemplary embodiments, or substitutions with equivalent structures or functions. The scope of the following claims should be interpreted in the broadest way to encompass all such modifications and equivalent structures and functions.

[0105] This application claims priority based on Japanese Patent Application No. 2024-166564 filed on September 25, 2024, and Japanese Patent Application No. 2025-85078 filed on May 21, 2025, and all of the contents of those applications are incorporated herein by reference.

Claims

1. A communication device capable of communicating with other communication devices using wireless frames compliant with the IEEE 802.11 standard series, wherein in the first frequency band of the first bandwidth used by the communication device for communication, there exists a second frequency band determined based on a second bandwidth that the other communication device can handle, and a third frequency band other than the second frequency band, and the communication device has, in frequency division multiplexing communication performed by the communication device with a plurality of devices including the other communication device, when the frequency resources of the second frequency band are allocated to a device other than the other communication device, acquisition means for acquiring capability information from the other communication device indicating whether the other communication device has the capability to change the frequency band used from the second frequency band to a fourth frequency band of the second bandwidth that includes a part of the third frequency band and perform the frequency division multiplexing communication, and communication means for allocating frequency resources to the other communication device and communicating with the other communication device, the communication means is A communication device that, based on the fact that the other communication device does not have the predetermined capability, allocates frequency resources from the second frequency band to the other communication device without changing the frequency band used by the other communication device, and allocates frequency resources to the other communication device from the second frequency band, or from the fourth frequency band after changing the frequency band used by the other communication device to the fourth frequency band, based on the fact that the other communication device has the predetermined capability.

2. The communication device according to claim 1, wherein the communication means communicates with the other communication device using Orthogonal Frequency Division Multiple Access (OFDMA).

3. The communication device according to claim 1 or 2, wherein, when allocating frequency resources from the fourth frequency band to the other communication device, the communication means issues an instruction in the second frequency band to change the frequency band used by the other communication device from the second frequency band to the fourth frequency band, receives a response from the other communication device to the instruction in the fourth frequency band, and communicates data with the other communication device in the fourth frequency band.

4. The communication device according to any one of claims 1 to 3, wherein the capability information includes information for identifying a range on the frequency axis that the other communication device can set as the fourth frequency band.

5. The communication device according to any one of claims 1 to 4, wherein the capability information includes information for specifying the time required for the other communication device to move from a state in which it is communicating in the second frequency band to a state in which it is capable of communicating in the fourth frequency band.

6. The communication device according to any one of claims 1 to 5, wherein the acquisition means acquires the capability information using a frame that includes a UHR Capabilities element.

7. The communication device according to any one of claims 1 to 6, wherein the communication means notifies the other communication device of a frequency resource allocated to it, by providing information for identifying a frequency band containing the frequency resource and information for uniquely identifying the frequency resource in the frequency band.

8. A communication device capable of communicating with other communication devices using wireless frames compliant with the IEEE 802.11 standard series, wherein in the first frequency band of a first bandwidth used by the other communication device for communication, there exists a second frequency band determined based on a second bandwidth that the communication device can handle, and a third frequency band other than the second frequency band, and the communication device has a notification means for notifying the other communication device of capability information indicating whether or not the communication device has the capability to change the frequency band used to perform frequency division multiplexing by changing the frequency band used from the second frequency band to a fourth frequency band of the second bandwidth that includes a part of the third frequency band, when the frequency resources of the second frequency band are allocated to a device other than the communication device, and the other communication device notifies the other communication device of the frequency resources in the second frequency band that were allocated based on the fact that the communication device does not have the predetermined capability, or A communication device comprising: acquisition means for acquiring specific information that identifies a frequency resource in the second frequency band or a frequency resource in the fourth frequency band, which is allocated based on the fact that the communication device has the predetermined capability; changing means for changing the frequency band to be used to the fourth frequency band when a frequency resource in the fourth frequency band is allocated; and communication means for communicating with the other communication device using the identified frequency resource.

9. The communication device according to claim 8, wherein the communication means communicates with the other communication device using Orthogonal Frequency Division Multiple Access (OFDMA).

10. The communication device according to claim 8 or 9, wherein when an instruction is received to change the frequency band used by the communication device from the second frequency band to the fourth frequency band, the changing means changes the frequency band used by the communication device from the second frequency band to the fourth frequency band, the communication means transmits a response to the instruction from the other communication device in the fourth frequency band, and communicates data with the other communication device in the fourth frequency band.

11. The communication device according to any one of claims 8 to 10, wherein the notification means notifies the capability information, which includes information for specifying a range on the frequency axis that the communication device can set as the fourth frequency band.

12. The communication device according to any one of claims 8 to 11, wherein the notification means notifies the capability information, which includes information for specifying the time required for the communication device to move from a state in which it is communicating in the second frequency band to a state in which it is capable of communicating in the fourth frequency band.

13. The communication device according to any one of claims 8 to 12, wherein the notification means notifies the capability information using a frame that includes a UHR Capabilities element.

14. The communication device according to any one of claims 8 to 13, wherein the identifying information includes information for identifying a frequency band including a frequency resource allocated to the communication device, and information for uniquely identifying the frequency resource allocated to the communication device in the said frequency band.

15. A control method performed by a communication device capable of communicating with other communication devices using wireless frames compliant with the IEEE 802.11 standard series, wherein in a first frequency band of a first bandwidth used by the communication device for communication, there exists a second frequency band determined based on a second bandwidth that the other communication device can handle, and a third frequency band other than the second frequency band, and the control method comprises: obtaining capability information from the other communication device indicating whether the other communication device has the capability to change the frequency band used from the second frequency band to a fourth frequency band of the second bandwidth that includes a part of the third frequency band in frequency division multiplexing communication performed by the communication device with a plurality of devices including the other communication device, when the frequency resources of the second frequency band are allocated to a device other than the other communication device; and allocating frequency resources to the other communication device and communicating with the other communication device, wherein the communication is performed A communication method comprising: allocating frequency resources to the other communication device from the second frequency band without changing the frequency band used by the other communication device, based on the fact that the other communication device does not have the predetermined capability; and allocating frequency resources to the other communication device from the second frequency band, or from the fourth frequency band by changing the frequency band used by the other communication device to the fourth frequency band, based on the fact that the other communication device has the predetermined capability.

16. A control method performed by a communication device capable of communicating with other communication devices using wireless frames compliant with the IEEE 802.11 standard series, wherein in a first frequency band of a first bandwidth used by the other communication device for communication, there exists a second frequency band determined based on a second bandwidth that the communication device can handle, and a third frequency band other than the second frequency band, and the control method provides capability information to the other communication device indicating whether or not the communication device has the capability to change the frequency band used to perform the frequency division multiplexing communication from the second frequency band to a fourth frequency band of the second bandwidth that includes a part of the third frequency band, when the frequency resources of the second frequency band are allocated to a device other than the communication device, and from the other communication device, the frequency resources in the second frequency band that were allocated based on the communication device not having the predetermined capability, or A control method comprising: obtaining specific information that identifies a frequency resource in the second frequency band or a frequency resource in the fourth frequency band that is allocated based on the fact that the communication device has the predetermined capability; changing the frequency band to be used to the fourth frequency band when a frequency resource in the fourth frequency band is allocated; and communicating with the other communication device using the identified frequency resource.

17. A program for causing a computer to function as each of the means of the communication device described in claim 1.

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