COMMUNICATION DEVICE, CONTROL METHOD, AND STORAGE MEDIUM

A communication device performs, based on a frequency resource that is to be allocated to communication of a first other communication device in accordance with a first communication standard, frequency resource allocation for communication of a second other communication device that conforms to a second communication standard. In the frequency resource allocation, in a case where the first other communication device and the second other communication device concurrently communicate with the communication device, a distribution of a first frequency resource to be allocated for communication using the first communication standard and a second frequency resource to be allocated for communication using the second communication standard in an available frequency band is determined, and a frequency resource included in the second frequency resource is allocated to the second other communication device.

BACKGROUND

Field

The present disclosure relates to a technique for controlling the allocation of resources in wireless communication.

Description of the Related Art

As communication standards on a wireless LAN (Wireless Local Area Network), the IEEE (Institute of Electrical and Electronics Engineers) 802.11 standards are known. The IEEE 802.11 standards are a series of standards including the IEEE 802.11a/b/g/n/ac/ax standards. International Publication No. 2017/073006 describes the IEEE 802.11ax standard in which communication is performed using OFDMA (orthogonal frequency division multiple access). The wireless communication by OFDMA can realize high peak throughput and can ensure sufficient communication speed in congested situations (see International Publication No. 2017/073006).

Currently, a new standard—the IEEE 802.11be standard—is being formulated for the IEEE 802.11 standard series in order to provide techniques for further improving throughput. In the IEEE 802.11be standard, in addition to realizing efficiency in utilization of high frequencies by using OFDMA as in IEEE 802.11ax, techniques for further improving performance are being considered.

It is anticipated that communication devices conforming to the IEEE 802.11ax standard and the IEEE 802.11be standard will be commonly used in the future. Therefore, a situation may occur in which a plurality of communication devices conforming to these standards coexist and perform communication in the same frequency band.

SUMMARY

Various embodiments of the present disclosure provide a resource allocation technique that enables efficient communication in an environment in which communication devices of a plurality of standards coexist.

According to one embodiment of the present disclosure, there is provided a communication device comprising: one or more processors; and one or more memories that store computer-readable instructions which, when executed by the one or more processors, cause the one or more processors to: based on a frequency resource that is to be allocated to communication of a first other communication device in accordance with a first communication standard, perform frequency resource allocation for communication of a second other communication device that conforms to a second communication standard, wherein in the frequency resource allocation, in a case where the first other communication device and the second other communication device concurrently communicate with the communication device, a distribution of a first frequency resource to be allocated for communication using the first communication standard and a second frequency resource to be allocated for communication using the second communication standard in an available frequency band is determined, and a frequency resource included in the second frequency resource is allocated to the second other communication device.

Further features of the present disclosure will become apparent from the following description of example embodiments with reference to the attached drawings.

DESCRIPTION OF THE EMBODIMENTS

FIG.1illustrates an example of a configuration of a wireless communication network according to the present embodiment. A network101is a wireless communication network in which a communication device capable of executing communication conforming to the IEEE 802.11be standard and a communication device capable of executing communication conforming to the IEEE 802.11ax standard coexist. IEEE is an abbreviation for Institute of Electrical and Electronics Engineers. IEEE 802.11be can also be called IEEE 802.11 EHT. EHT is an abbreviation for Extremely High Throughput or Extreme High Throughput. IEEE 802.11ax can also be called IEEE 802.11 HE. HE is an abbreviation for High Efficiency.

In one example, the network101includes an AP102and an STA103conforming to the IEEE 802.11be standard and an STA104capable of performing communication conforming to the IEEE 802.11ax standard. AP refers to an access point, and STA refers to a station. It is assumed that the AP102is capable of performing communication based on the IEEE 802.11ax standard. That is, the AP102can communicate with the STA103in accordance with, for example, the wireless communication method of the IEEE 802.11be standard and communicate with the STA104in accordance with the wireless communication method of the IEEE 802.11ax standard. In the following, a device that executes communication conforming to the IEEE 802.11be standard is referred to as an EHT device, and a device that executes communication conforming to IEEE 802.11ax standard may be referred to as an HE device.

Each communication device can communicate in at least one frequency band of a 2.4-GHz band, a 5-GHz band, and a 6-GHz band. However, this is an example, and a different frequency band may be used, such as a 60-GHz band, for example. Also, each communication device can communicate in any signal bandwidth of 20 MHz, 40 MHz, 80 MHz, 160 MHz, and 320 MHz. A plurality of signals are multiplexed between the AP102and the STA103and the STA104by using OFDMA (orthogonal frequency division multiple access), and the communication of a plurality of users (STAs) is concurrently performed. The communication concurrently performed for such a plurality of users can be called multi-user (MU) communication. The AP102and the STA103may each have a plurality of antennas and may be configured to be capable of performing MIMO (Multiple-Input and Multiple-Output) communication. In such a case, a transmission-side apparatus generates a signal corresponding to each of the plurality of antennas from the plurality of data streams and transmit, from each of the plurality of antennas, a signal corresponding to each of the plurality of antennas using the same frequency channel. Then, a reception-side device concurrently receives those signals using a plurality of antennas and separates each data stream from the received signal and decodes them. By executing MIMO communication, the AP102and the STA103can transmit and receive more data in the same amount of time compared with the case where MIMO communication is not executed. The AP102can establish a radio link with the STA103or the STA104via connection processing such as association processing conforming to the standards of the IEEE 802.11 series.

The example of the network configuration ofFIG.1is merely an example, and for example, a large number of EHT devices and HE devices may be included in a wider region. Further, other communication devices conforming to the legacy standards (IEEE 802.11a/b/g/n/ac standards) or the like prior to the IEEE 802.11ax standard may be included in the network. The AP102, the STA103, and the STA104may also support the legacy standards described above. In addition, the AP102, the STA103and the STA104may 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. Here, OFDM is an abbreviation for Orthogonal Frequency Division Multiplexing. In addition, NFC is an abbreviation for Near Field Communication. UWB includes wireless USB, wireless1394, Winet, and the like. In addition, the AP102, the STA103and the STA104may support a communication standard for wired communication such as a wired LAN.

The AP102may be a wireless LAN router, a personal computer (PC) or the like as one example but is not limited to these. That is, the AP102may be any communication device capable of performing communication with other communication devices using OFDMA in accordance with the IEEE 802.11be standard. The AP102may also be an information processing apparatus such as a radio chip that is capable of performing wireless communication conforming to the IEEE 802.11be standard. Also, the STA103may be, as one example, a camera, a tablet, a smart phone, a PC, a cell phone, a video camera, a headset, or the like but is not limited to these. That is, the STA103may be any communication device capable of performing communication with other communication devices using OFDMA in accordance with the IEEE 802.11be standard. The STA103may also be an information processing apparatus, such as a radio chip that is capable of performing wireless communication conforming to the IEEE 802.11be standard. The STA104may be any communication device that is capable of performing wireless communication conforming to the IEEE 802.11ax standard or an information processing apparatus, such as a radio chip. The information processing apparatus, such as a radio chip, has an antenna for transmitting a generated signal.

In the IEEE 802.11ax standard and the IEEE 802.11be standard, a frequency resource of a predetermined frequency bandwidth in which a predetermined number of OFDMA subcarriers are combined are provided as a Resource Unit (RU). An RU is a unit of frequency resources configured by a predetermined number of subcarriers, and frequency resources are allocated to an STA with an RU as the smallest unit. The IEEE 802.11ax standard and the IEEE 802.11be standard define a 26-tone RU, a 52-tone RU, a 106-tone RU, and the like in which 26 subcarriers, 52 subcarriers, 106 subcarriers, and the like, respectively, are combined as one RU. Further, in the IEEE 802.11ax standard and the IEEE 802.11be standard, a frequency bandwidth that can be used for communication is variably configured to be 20 MHz, 40 MHz, 80 MHz, 160 MHz, or the like. Within a frequency band that is used, an RU is associated with a serial number, and by specifying any of the serial numbers, an RU corresponding to that number is specified, and in accordance with that, a corresponding subcarrier number is specified. In a case where the frequency bandwidth to be used is 20 MHz or 40 MHz, the subcarrier numbers corresponding to each RU defined in the IEEE 802.11ax standard and the IEEE 802.11be standard are the same. Meanwhile, in other cases, it is also possible that subcarrier numbers corresponding to each RU may not coincide.

When an STA that operates in conformance with the IEEE 802.11ax standard or the IEEE 802.11be standard transmits a signal to an AP, the STA can transmit the signal to the AP in an RU that has been allocated to itself. The AP transmits a trigger frame, which will be described later, to a plurality of STAs, and the STAs transmit a signal in an allocated RU in response to receiving the trigger frame. In the IEEE 802.11ax standard and the IEEE 802.11be standard, UL-MU (UpLink Multi-User) transmission by OFDMA is performed by a plurality of STAs transmitting a signal in a different RU in accordance with a trigger frame. UpLink refers to a link in a direction in which a signal is transmitted from an STA to an AP.

A configuration of the AP102for efficiently allocating an RU to an STA conforming to the IEEE 802.11ax standard and an STA conforming to the IEEE 802.11be standard and a flow of processing thereof will be described in the following.

FIG.2is a diagram illustrating an example of a hardware configuration of the AP102according to the present embodiment. The AP102includes, for example, a storage unit201, a control unit202, a functional unit203, an input unit204, an output unit205, a communication unit206, and an antenna207. Although the STA103and the STA104may also have the same configuration, description will be given here focusing on the AP102.

The storage unit201is configured to include one or more memories, such as a ROM and a RAM, for example, and stores various kinds of information such as a computer program for performing various operations to be described later and communication parameters for wireless communication. ROM is an abbreviation of Read Only Memory, and RAM is an abbreviation of Random Access Memory. In addition to or in place of a memory, such as a ROM or a RAM, the storage unit201may include a storage medium such as a flexible disk, a hard disk, an optical disk, a magnetic optical disk, a CD-ROM, CD-R, a magnetic tape, a non-volatile memory card, or a DVD. The storage unit201may also include a plurality of memories or the like.

The control unit202is configured by one or more processors, such as a CPU and an MPU, for example, and controls the entire AP102by executing a computer program stored in the storage unit201, for example. CPU is an abbreviation of Central Processing Unit, and MPU is an abbreviation of Micro Processing Unit. In addition to controlling the entire AP102, the control unit202may be configured to perform processing for generating data or a signal (a radio frame) to be transmitted when communicating with another communication device (e.g., the STA103). The control unit202may be configured to execute processing such as control of the entire AP102by, for example, a computer program stored in the storage unit201and an OS (Operating System) cooperating. Further, the control unit202includes a plurality of processors, such as a multi-core, and may execute processing such as overall control of the AP102by the plurality of processors. Further, the control unit202may be configured by an ASIC (Application Specific Integrated Circuit), a DSP (Digital Signal Processor), an FPGA (Field Programmable Gate Array), or the like.

Further, the control unit202executes predetermined processing, such as image capturing, printing, or projection by controlling the functional unit203. The functional unit203is hardware for the AP102to perform predetermined processing. For example, if the AP102is a camera, the functional unit203is an image capturing unit and performs image capturing processing. In addition, for example, if the AP102is a printer, the functional unit203is a printing unit and performs printing processing. In addition, for example, if the AP102is a projector, the functional unit203is a projection unit and performs projection processing. The data to be processed by the functional unit203may be data stored in the storage unit201or data communicated with another communication device (e.g., the STA103) via the communication unit206, which will be described later.

The input unit204accepts various operations from the user. The output unit205performs various outputs to the user. Here, output by the output unit205includes, for example, at least one of a display on a screen, audio output by a speaker, vibration output, and the like. Both the input unit204and the output unit205may be realized by one module such as in the case of a touch panel. The input unit204and the output unit205may each be built in the AP102or may be configured as an external device to be connected to a communication device.

The communication unit206controls wireless communication conforming to the IEEE 802.11 standard series and controls IP communication. In the present embodiment, the communication unit206is particularly configured to control wireless communication conforming to the IEEE 802.11be standard and control, as necessary, wireless communication conforming to the IEEE 802.11ax standard. Further, the communication unit206may be configured to control wireless communication conforming to the legacy standards described above in the IEEE 802.11 standards. Further, the communication unit206may be configured to control wired communication such as a wired LAN. The communication unit206transmits and receives a signal for wireless communication generated by the control unit202, for example, by controlling the antenna207. The AP102may be configured to include a plurality of communication units206. In such a case, the AP102can perform a multi-link communication by establishing a plurality of links, each of which is established using one communication unit206. The AP102may establish a plurality of links using one communication unit206. In such a case, the communication unit206can perform communication via a plurality of links by, for example, switching the operating frequency channel in a time division manner. When the AP102corresponds to the NFC standard, the Bluetooth standard, or the like, the communication unit206may also control wireless communication conforming to these communication standards. When the AP102is configured so as to be capable of executing wireless communication conforming to a plurality of communication standards, the communication unit206and the antenna207corresponding to each communication standard may be individually provided. Further, the AP102communicates data, such as image data, document data, and video data, with a communication partner device (e.g., the STA103or the STA104) via the communication unit206. The antenna207may be provided separately from the communication unit206or may be configured as one module combined with the communication unit206.

The antenna207is an antenna that enables communication in a sub-GHz band, a 2.4-GHz band, a 5-GHz band, and a 6-GHz band. The AP102may have a multiband antenna as the antenna207or may have, for each frequency band, a plurality of antennas corresponding to the respective frequency bands. Further, when having a plurality of antennas207, the AP102may have a plurality of communication units206corresponding to each of the plurality of antennas or may have a smaller number of communication units206than the number of antennas such as one communication unit206for a plurality of antennas. The antenna207may be a single antenna or an antenna array. That is, the antenna207may have a plurality of antenna elements and may be configured to be capable of performing multi-antenna communication such as MIMO, for example.

FIG.3illustrates an example of a functional configuration of the AP102. The AP102includes, for example, an RU allocation control unit301, a trigger frame generation unit302, and a frame transmission/reception unit303as its functional configuration.

The RU allocation control unit301allocates an RU to the STA103and the STA104with which a radio link has been established. The trigger frame generation unit302generates a trigger frame that gives an opportunity for an STA to transmit a signal based on the allocation of an RU determined by the RU allocation control unit301. The frame transmission/reception unit303controls the transmission and reception of a management frame which includes the trigger frame, a control frame, and a data frame. A trigger frame generated by the trigger frame generation unit302is transmitted to the STA103and the STA104by the frame transmission/reception unit303. Based on the content of the trigger frame, the STA103and the STA104transmit signals in RUs that have been allocated to themselves. This allows the STA103and the STA104to transmit a signal to the AP102in an UL-MU transmission by OFDMA.

Here, a format of a trigger frame will be described with reference toFIG.4. The fields/subfields illustrated here conform to the format specified in IEEE 802.11ax. That is, the trigger frame contains the respective fields of Frame Control401, Duration402, RA403, TA404, Common Info405, User Info406, Padding407, and FCS408. Among these fields, the Common Info field405includes information shared by a plurality of STAs for which communication is multiplexed by OFDMA. In addition, the User Info field406contains unique information for each of the plurality of STAs. The number of User Info fields406to be provided corresponds to the number of STAs. In one example, a frequency bandwidth to be used is notified to all of the target STAs by a UL BW subfield412in the Common Info field405. Meanwhile, allocation information, which indicates the allocation of an RU to be used by each STA, is notified individually to each STA by an AID12 subfield421and an RU Allocation subfield422in the User Info field406. The AID12 subfield421stores an AID (Association ID), which is identification information capable of uniquely specifying an STA, which has been allocated to the STA at the time of association. Thus, it becomes possible for an STA that has received this frame to specify which User Info field406information for itself is stored in. Then, the STA specifies the RU that has been allocated to itself by confirming the RU Allocation subfield422in the User Info field406in which its AID is stored in the AID12 subfield421. A serial number is associated with each RU, and among those serial numbers, a number corresponding to an RU to be allocated to the STA is stored in the RU Allocation subfield422.

Next, an example of a flow of processing for allocating an RU to be executed by the AP102will be described. The processing to be described below is realized by the control unit202reading and executing a computer program stored in the storage unit201when the AP102determines the allocation of an RU. Dedicated hardware for executing the following process may be used, or an implementation such that a processor included in the communication unit206, for example, executes the following process may be used.

Processing Example 1

In the present example of the processing, a case where the frequency bandwidth to be used is 20 MHz and a 52-tone RU is allocated to the STA103and the STA104will be described. If the frequency bandwidth to be used is 20 MHz, four 52-tone RUs are defined. These four RUs are called an RU 1 to an RU 4, respectively. Table 1 illustrates the subcarrier numbers corresponding to each of the RU 1 to the RU 4. In this table, [x:y] indicates a group of subcarriers between a subcarrier number x and a subcarrier number y.

In the present example of the processing, a method of allocating these four RUs will be described.

FIG.5illustrates an example of the flow of processing executed by the RU allocation control unit301of the AP102in the present example of the processing.

This processing is performed, for example, when the AP102determines the allocation of RUs or generates a trigger frame. In this processing, the AP102first determines candidates for an STA to be allocated an RU (step S501). For example, the AP102uses a BSR (Buffer Status Report) or the like to confirm the state of accumulation of transmission queues (data to be transmitted) of each STA that has established a connection with the AP102and determines candidates for an STA to be allocated an RU based on the result. For example, the AP102may select, as candidates to be allocated an RU, STAs whose amount of data to be transmitted held in a buffer exceeds a predetermined amount. The AP102then determines whether the candidates for an STA to be allocated an RU include both an STA that operates in accordance with the IEEE 802.11ax standard and an STA that operate in accordance with the IEEE 802.11be standard (step S502). In the following, an STA that operates in accordance with the IEEE 802.11ax standard is referred to as an HE-STA, and an STA that operates in accordance with the IEEE 802.11be standard is referred to as an EHT-STA. A network in which communication is performed in accordance with the IEEE 802.11ax standard is called an HE network, and a network in which communication is performed in accordance with the IEEE 802.11be standard is called an EHT network.

When it is determined that both an HE-STA and an EHT-STA are included in the candidates for an STA to be allocated an RU (YES in step S502), the AP102sets each of the four RUs indicated in Table 1 to either an HE-priority RU or an EHT-priority RU (step S503). The AP102determines, for example, the number of HE-priority RUs and the number of EHT-priority RUs based on the transmission band required in each of the HE network and the EHT network. For example, if the transmission band required by the HE network and the EHT network are the same, the AP102sets two RUs to the HE-priority RU and the other two RUs to the EHT-priority RU. Which RU to make an HE-priority RU and which RU to make an EHT-priority RU can be determined by any method.

Next, the AP102selects, from among the candidates for an STA to be allocated an RU, an STA to be allocated an RU (step S504). The AP102may, for example, select an STA preferentially from ones having a smaller corresponding AID. However, this is merely an example, and the AP102may, for example, allocate an RU preferentially to an STA with a higher AID. The AP102may allocate an RU preferentially to an STA with a smaller MAC (Media Access Control) address or an STA with a larger MAC address. In addition, the AP102may allocate an RU with priority to HE-STAs or EHT-STAs.

When an EHT-STA has been selected in step S504(YES in step S505), the AP102determines whether there are RUs that have not yet been allocated among the EHT-priority RUs set in step S503(step S506). Next, if there are EHT-priority RUs that have not yet been allocated (YES in step S506), the AP102allocates, to the STA that has been selected in step S504, an RU from the RUs that have not yet been allocated (step S507). Meanwhile, if there are no EHT-priority RUs that have not yet been allocated (NO in step S506), the AP102selects another STA from among the candidates for an STA to be allocated an RU without allocating an RU to the STA that has been selected in the last step S504(step S504). In the selection of this another STA, processing such as that in which an EHT-STA is not selected (or such that an HE-STA is preferentially selected) can be performed.

When an HE-STA has been selected in step S504(NO in step S505), the AP102determines whether there are RUs that have not yet been allocated among the HE-priority RUs set in step S503(step S508). Next, if there are HE-priority RUs that have not yet been allocated (YES in step S508), the AP102allocates, to the STA that has been selected in step S504, an RU from the RUs that have not yet been allocated (step S509). Meanwhile, if there are no HE-priority RUs that have not yet been allocated (NO in step S508), the AP102selects another STA from among the candidates for an STA to be allocated an RU without allocating an RU to the STA that has been selected in the last step S504(step S504). In the selection of this another STA, processing such as that in which an HE-STA is not selected (or such that an EHT-STA is preferentially selected) can be performed.

Then, if the allocation of RUs has been completed for all the STA candidates determined in step S501(i.e., if all the STA candidates have been selected in step S504) (YES in step S510), the AP102ends the processing. The AP102may determine, in step S501, a number of STA candidates that are greater than or equal to the number of RUs and, when all of the RUs have been allocated to one of the STAs, end the processing. That is, the AP102determines, in step S510, whether a state in which no more RUs can be allocated has been entered. Then, when it is determined that no more RUs can be allocated (YES in step S510), the AP102ends the processing, and when RUs can still be allocated (NO in step S510), the AP102returns the processing to step S504.

When it is determined that only either HE-STAs or EHT-STAs are included in the candidates for an STA to be allocated an RU determined in step S501(NO in step S502), the AP102performs processing for allocating an RU without setting HE-priority RUs and EHT-priority RUs. That is, similarly to step S504, the AP102selects, from among the candidates for an STA to be allocated an RU, an STA to be allocated an RU (step S511) and allocates an RU to that STA (step S512). Then, the AP102determines whether a state in which no more RUs can be allocated has been entered (step S512). Then, when it is determined that no more RUs can be allocated (YES in step S512), the AP102ends the processing, and when RUs can still be allocated (NO in step S512), the AP102returns the processing to step S511.

By the above-described processing in steps S503to S510, the AP102can adaptively allocate RUs in accordance with a transmission band required for each of the HE network and the EHT network in a system in which HE-STAs and EHT-STAs coexist. Also, due to the operation in steps S511to S513, if, for example, the candidates for an STA to be allocated an RU are only HE-STAs or EHT-STAs, all of the RUs can be utilized efficiently without providing HE or EHT-priority RUs.

In the above example, the number of HE-priority RUs and the number of EHT-priority RUs are determined based on a transmission band required in each of the HE network and the EHT network; however, the present invention is not limited to this. For example, the AP102may determine the number of HE-priority RUs and EHT-priority RUs based on the number of HE-STAs and the number of EHT-STAs that have established a connection with the AP102instead of or in addition to the transmission band. That is, the AP102may have more RUs to be allocated for the communication standard of a larger number of STAs. The AP102may also determine the number of HE-priority RUs and EHT-priority RUs from the number of HE-STAs and the number of EHT-STAs among the candidates for an STA to be allocated an RU determined in step S501.

Further, in the above example, an example in which the AP102determines whether to use an RU as either an HE-priority RU or an EHT-priority RU by any method has been described, but the present invention is not limited to this. For example, an RU with a sufficiently high radio quality, such as an SNR (signal-to-noise ratio) or an SINR (signal-to-interference-plus-noise ratio), may be set as an EHT-priority RU. For example, it is assumed that an EHT-STA supports a modulation scheme of a higher modulation level (the number of information types or the number of bits that can be transmitted in one symbol) than an HE-STA, such as a case where an HE-STA supports 1024 QAM (Quadrature Amplitude Modulation) and an EHT-STA supports 4096 QAM. Generally, the higher the modulation level of a modulation scheme, the higher the required radio quality (such as an SNR or an SINR). Therefore, by making an RU whose radio quality is good an EHT-priority RU, it becomes possible to use a modulation scheme of a higher modulation level to communicate with higher efficiency, thereby enabling to improve frequency utilization efficiency. In such a case, the AP102can determine which RU is set to an EHT-priority RU by measuring the noise level of each RU. The AP102may also specify the radio quality that each of the EHT-STAs that are candidates to be allocated an RU obtains at each RU by receiving, from each EHT-STA, a report such as CSI (Channel State Information). The AP102may also specify by measuring a signal transmitted from each of the EHT-STAs that are candidates to be allocated an RU. Then, RUs capable of ensuring a sufficient radio quality in any of the EHT-STAs, may be made EHT-priority RUs. The AP102may also determine, as EHT-priority RUs, the RUs in the vicinity of DC subcarriers, which are less susceptible to radio quality degradation due to frequency deviations. DC means direct current and, here, means the center of the available subcarriers, i.e., the center frequency in a signal band. If there may be an STA that does not support 4096 QAM despite being an EHT-STA, the AP102may allocate an EHT-priority RU whose radio quality is good preferentially to an EHT-STA that has been confirmed to support 4096 QAM.

Further, in the above-described example of the processing, when it is determined in steps S506and S508that an EHT-priority RU or an HE-priority RU is non-allocable, the AP102does not allocate an RU to an STA that has been selected in step S504; however, the present invention is not limited to this. For example, the AP102may allocate an EHT-priority RU to an HE-STA if it is determined that the allocation of RUs has been completed for all candidate STAs in step S510without the allocation of RUs to HE-STAs when EHT-priority RUs are remaining. By virtue of this, it becomes possible to suppress the deterioration of the frequency utilization efficiency due to EHT-priority RUs or HE-priority RUs not being used. Also, if the processing is ended due to exhaustion of allocable RUs without RUs being allocated to one of the STA candidates determined in step S501, then in the next transmission opportunity, the AP102may allocate RUs preferentially to the STAs not allocated an RU. For example, the AP102may execute the processing ofFIG.5when the next trigger frame is transmitted and, in such a case, may preferentially select STAs previously not allocated an RU in step S504. This makes it possible to ensure fairness in the allocation of an RU to each STA.

Processing Example 2

As described above, in a case where the frequency bandwidth to be used is 20 MHz or 40 MHz, the subcarriers corresponding to each RU of the IEEE 802.11ax standard and the IEEE 802.11be standard are the same. Meanwhile, in a case where the frequency bandwidth to be used is 80 MHz, the subcarriers corresponding to each RU of the IEEE 802.11ax standard and the IEEE 802.11be standard do not coincide. Here, Table 2 illustrates the subcarrier numbers corresponding to each RU for when an 80-MHz frequency bandwidth and 52-tone RUs are used in the IEEE 802.11ax standard. In addition, Table 3 illustrates the subcarrier numbers corresponding to each RU for when an 80-MHz frequency bandwidth and 52-tone RUs are used in the IEEE 802.11be standard. In the following, an RU of the IEEE 802.11ax standard is referred to as an HE-RU, and an RU of the IEEE 802.11be standard is referred to as an EHT-RU.

Here, a case where the AP102allocates an EHT-RU 12 to the STA103and an HE-RU 11 to the STA104will be considered. In such a case, since the STA103operates in accordance with the IEEE 802.11be standard, it performs an UL-MU transmission using subcarriers having subcarrier numbers 201 to 252. Meanwhile, since the STA104operates in accordance with the IEEE 802.11ax standard, it performs an UL-MU transmission using subcarriers having subcarrier numbers 152 to 203. Consequently, both the STA103and the STA104will transmit a signal on the subcarriers with the subcarrier numbers 201 to 203. Therefore, in these subcarriers, the signal transmitted from the STA103and the signal transmitted from the STA104interfere with each other. As a result, the AP102fails to receive these signals, and due to retransmission or the like being performed, for example, the frequency utilization efficiency of the entire system may decrease.

In view of such circumstances, in the present example of the processing, the frequency bandwidth to be used is 80 MHz, and the AP102respectively allocates a 52-tone RU to the STA103and the STA104considering the difference in the subcarriers corresponding to each RU. For this reason, in the processing of determining an HE-priority RU/EHT-priority RU in step S503ofFIG.5, the AP102executes the processing such as inFIG.6. That is, the AP102first determines the number of EHT-priority RUs and determines which RUs are to be EHT-priority RUs (step S601). Then, the AP102determines, as an HE-priority RU, an HE-RU that does not interfere with the EHT-priority RUs that have been set in step S601(step S602).

FIGS.7and8illustrate examples for when HE-priority RUs/EHT-priority RUs have been allocated in accordance with the present example of the processing.FIG.7illustrates an example in which the AP102sets the number of EHT-priority RUs as 8 and an RU 5 to an RU 12 as EHT-priority RUs.FIG.8illustrates an example in which the AP102sets the number of EHT-priority RUs as 10 and the RU 1 to the RU 5 and the RU 12 to an RU 16 as EHT-priority RUs. In the example ofFIG.7, in step S601, the RU 5 to the RU 12 are set as EHT-priority RUs, and subcarriers with subcarrier numbers −252 to 252 corresponding to these RUs are used for communication that conforms to the IEEE 802.11be standard. Then, the AP102determines, as HE-priority RUs HE-RUs that do not include the subcarriers corresponding to these EHT-priority RUs. That is, here, the AP102determines the RU 1 to the RU 4 and the RU 13 to the RU 16 as HE-priority RUs. Meanwhile, in the example ofFIG.8, the AP102sets the RU 1 to the RU 5 and the RU 12 to the RU 16 as EHT-priority RUs, and subcarriers with subcarrier numbers −499 to −201 and 201 to 499 are used for communication that conforms to IEEE 802.11be standard. If the RU 6 and the RU 11 are determined to be HE-priority RUs, they may interfere with the RU 5 and the RU 12 that have been set as EHT-priority RUs in subcarriers with subcarrier numbers −203 to −201 and 201 to 203. For this reason, even though the RU 6 and the RU 11 are not EHT-priority RUs, the AP102does not set these as HE-priority RUs and determines only the RU 7 to the RU 10 as HE-priority RUs. With such a setting, it becomes possible to prevent the communication of EHT-STAs and the communication of HE-STAs from interfering with each other in an environment where the corresponding subcarriers of at least some EHT-RUs and HE-RUs do not coincide.

As described above, in a system in which HE-STAs and EHT-STAs coexist, it is possible to prevent interference between HE-RUs and EHT-RUs and allocate the RUs adaptively for each of the HE network and the EHT network.

The AP102generates and transmits to the STA103and the STA104a trigger frame containing information indicating the allocation of RUs that have been determined by the above-described processing. This makes it possible to, when the STA103and the STA104concurrently transmit a signal, instruct these STAs to use frequency resources such that the signals of these STAs do not interfere with each other.

The above-described method relates to a technique for allocating frequency resources between the IEEE 802.11ax standard and the IEEE 802.11be standard but, for example, may be applied to another standard of the IEEE 802.11 standard series. It may also be used, for example, for when allocating resources by coordination between a cellular communication standard and the IEEE 802.11 standard. For example, when performing communication of a cellular communication standard (e.g., long term evolution or fifth generation) in the frequency band of a wireless LAN, the above-described method may be applied. In one example, the frequency resources in which RUs of the communication of the IEEE 802.11ax standard or the IEEE 802.11be standard can be preferentially placed and the frequency resource in which resource blocks of the communication of a cellular communication standard can be preferentially placed can be determined. The determination may be made based on the transmission band or the like necessary for communication in each system. Then, in the frequency resources in which the communication of a wireless LAN is prioritized, RUs for the IEEE 802.11ax standard and the IEEE 802.11be standard are allocated, and in the frequency resources in which cellular communication is prioritized, the resource blocks of a cellular communication are allocated. The AP102may acquire, from a node of a cellular communication system, information by which a transmission band or the like required for cellular communication can be specified and determine the frequency resources that are prioritized for each of the wireless LAN and the cellular communication. The AP102also notifies the node of the cellular communication system of information indicating the frequency resources in which it has been determined that cellular communication is prioritized. By virtue of this, the communication of a cellular communication standard and the communication of a wireless LAN standard can be concurrently performed without interfering with each other. Further, the above-described processing may be performed with another communication standard other than the cellular communication standard. When adjusting frequency resources with a standard other than a wireless LAN such as a cellular communication standard, the AP102may only allocate the RUs of the wireless LAN after determining the resources that are prioritized for each system.

The AP102may be configured to operate only in one of the IEEE 802.11ax standard and the IEEE 802.11be standard, for example. In one example, the AP102may obtain, from another AP, information by which a required transmission band or the like, such as information on the amount of data to be transmitted held in an STA that is connected by the IEEE 802.11ax standard to that another AP, can be specified. Then, based on this information, the AP102specifies the transmission band or the like that is necessary for communication in the IEEE 802.11ax standard in another AP. Further, the AP102specifies, from the amount of data to be transmitted or the like held in the STA conforming to the IEEE 802.11be standard connected to the AP102, the transmission band or the like that is necessary for communication in the IEEE 802.11be standard. The AP102may then determine HE-priority RUs for communication in the IEEE 802.11ax standard in another AP and EHT-priority RUs for communication in IEEE 802.11be standard in the AP102. In such a case, the AP102notifies another AP of the determined HE-priority RUs and allocates an RU from the EHT-priority RUs to an EHT-STA connected to the AP102. Thus, it is possible to cooperate and execute communication by different communication standards between a plurality of APs. Similarly, the above-described processing can be used when an AP cooperates with another AP to concurrently communicate with surrounding STAs operating in a plurality of versions of a wireless LAN communication standard.

In the above-described embodiment, description has been given for the procedure for determining the distribution of the number of RUs; however, allocable frequency resources need not be defined by a unit such as RU. That is, so long as it is a determination of a distribution of frequency resources to be respectively allocated for communication conforming to each of the plurality of communication standards in an available frequency band, the distribution may be executed without using a fixed unit of frequency resource as a standard.

Further, in the present embodiment, a configuration in which the AP102determines the allocation of RUs has been described, but a control device for controlling one or more APs102may be separately provided, and the control device may determine the allocation of RUs in the one or more APs102.

In the embodiment described above, the process for transmitting an uplink signal to the STA103and the STA104has been described, but the same method can be applied to the allocation of RUs in downlink.

OTHER EMBODIMENTS

This application claims the benefit of Japanese Patent Application No. 2021-093148, filed Jun. 2, 2021, which is hereby incorporated by reference herein in its entirety.