Communication device, communication method, and program

Abstract

This communication device that executes communication conforming to the IEEE 802.11 standard series transmits a control frame including information on repetition for transmitting a radio frame including repeated data on a time axis to a partner device, and receives the radio frame from the partner device.

Description

Communication device, communication method, and program

[0001] The present invention relates to a technology for efficiently notifying information associated with repeated data in a communication method for repeatedly transmitting data.

[0002] The Institute of Electrical and Electronics Engineers (IEEE) 802.11 series of standards is known as a communication standard for wireless LANs (Local Area Networks). The IEEE 802.11 series of standards includes standards such as IEEE 802.11a / b / g / n / ac / ax / be. In formulating the IEEE 802.11be standard and its successor standards, it has been considered to improve communication efficiency and throughput and reduce delays by having multiple access point (AP) devices operate cooperatively.

[0003] In particular, for the IEEE 802.11bn standard, which is being considered as a successor to the IEEE 802.11be standard, discussions are underway on methods for improving communication reliability. The IEEE 802.11bn standard may also be referred to as the Ultra High Reliability (UHR) standard. Patent Document 1 discloses a method for transmitting the same data in parallel via multiple frequency channels as one method for improving communication reliability.

[0004] Japanese Patent Application Laid-Open No. 2021-103805

[0005] The present invention provides a technique for efficiently notifying information associated with repeated data in a communication method in which data is repeatedly transmitted.

[0006] A communication device according to one aspect of the present invention is a communication device that performs communication in accordance with the IEEE 802.11 standard series, and has a transmitting means that transmits to the other device a control frame that includes information regarding repetition so that the other device can transmit a wireless frame that includes data repeated on a time axis, and a receiving means that receives the wireless frame from the other device.

[0007] According to the present invention, in a communication method for repeatedly transmitting data, it is possible to efficiently notify information associated with the repeated data.

[0008] 1 is a diagram illustrating an example of the configuration of a wireless communication system; 2 is a diagram illustrating an example of the hardware configuration of a communication device; 3 is a diagram illustrating an example of the functional configuration of a communication device; 4 is a diagram illustrating an example of the configuration of a wireless frame including data repeated on a time axis; 5 is a diagram illustrating a first example of a format of a trigger frame; 6 is a diagram illustrating an example of an operation when an AP transmits a trigger frame; 7 is a diagram illustrating an example of an operation when an AP transmits a trigger frame; 8 is a diagram illustrating an example of an operation when an STA receives a trigger frame; and 9 is a diagram illustrating a second example of a format of a trigger frame.

[0009] Hereinafter, embodiments will be described in detail with reference to the accompanying drawings. Note that the following embodiments do not limit the scope of the invention claimed. Although multiple features are described in the embodiments, not all of these multiple features are necessarily essential to the invention, and multiple features may be combined arbitrarily. Furthermore, in the accompanying drawings, the same reference numerals are used to designate the same or similar components, and redundant explanations will be omitted.

[0010] (System Configuration) Fig. 1 shows an example configuration of a wireless communication system according to this embodiment. This wireless communication system includes, for example, one access point (AP) 101 and three non-AP stations (Non-AP STAs, hereinafter STAs) 102-104. The STAs 102-104 may be collectively referred to as STA 110. A network 105 formed by the AP 101 indicates the range over which the AP 101 and the STAs 102-104 can communicate. That is, within the range of the network 105, the STAs 102-104 can receive signals transmitted by the AP 101, and signals transmitted by the STAs 102-104 can be received by the AP 101. The AP 101 and the STAs 102-104 are communication devices capable of wireless communication compliant with the IEEE 802.11 series of standards, including the IEEE 802.11bn standard. IEEE stands for Institute of Electrical and Electronics Engineers. The IEEE 802.11bn standard is the successor to IEEE 802.11be, targeting a maximum transmission speed of 46.08 Gbps. The IEEE 802.11bn standard lists high-reliability communication, low-latency communication, and improved throughput during congestion as its main features. The IEEE 802.11bn standard may also be called the UHR standard. UHR may also be an abbreviation for Ultra High Reliability. A wireless frame communicated according to the IEEE 802.11bn standard may be referred to as a UHR (Ultra High Reliability) PPDU. PPDU is an abbreviation for Physical Layer (PHY) Protocol Data Unit. In this embodiment, a wireless frame communicated based on the IEEE 802.11 series standard may be referred to as a PPDU. A PPDU may include a UHR PPDU. Note that the names IEEE 802.11bn standard and UHR standard were established for convenience, taking into account the goals to be achieved when developing these standards and the main features to be set forth in their development. Therefore, these may be called different names once the development of the standards is complete.However, this specification and the accompanying claims are applicable to essentially any standard that may be a successor to the IEEE 802.11be standard.

[0011] The IEEE 802.11 series standards may include the IEEE 802.11a / b / g / n / ac / ax / be standards. These standards may be referred to as legacy standards. That is, the AP 101 and the STAs 102-104 may support one or more legacy standards in addition to the IEEE 802.11bn standard. Note that the AP 101 and the STAs 102-104 may also support other communication standards such as Bluetooth (registered trademark), NFC, UWB, ZigBee, and MBOA in addition to the IEEE 802.11 series standards. Note that UWB stands for Ultra Wide Band, and MBOA stands for Multi Band OFDM Alliance. Furthermore, NFC is an abbreviation for Near Field Communication. UWB includes wireless USB, wireless 1394, WiNET, etc. Furthermore, the AP 101 and the STAs 102 to 104 may be compatible with a communication standard for wired communication such as a wired LAN.

[0012] While FIG. 1 shows a state in which one AP 101 and three STAs 102-104 exist, there may be one STA 110 or four or more, and there may be multiple APs. Furthermore, multiple STAs may connect to one AP, or one STA may connect to multiple APs. The AP 101 may be, but is not limited to, a wireless LAN router or a personal computer (PC). The STA 110 may be, but is not limited to, any electronic device, such as a smartphone, tablet, mobile phone, PC, video camera, headset, printer, or display. The AP 101 and the STA 110 may also be information processing devices, such as wireless chips, capable of performing wireless communication compliant with the IEEE 802.11bn standard. In this embodiment, the AP 101 and the STAs 102-104 may be referred to as communication devices 100 without distinction.

[0013] The communication device 100 may communicate using radio signals in frequency bands such as the 2.4 GHz band, the 3.6 GHz band, the 5 GHz band, the 6 GHz band, and the 45 GHz band and 60 GHz band, which are called millimeter waves. The frequency bands used by the communication device 100 are not limited to these and may be, for example, the Sub 1 GHz band. The communication device 100 may also communicate using bandwidths of 20 MHz, 40 MHz, 80 MHz, 160 MHz, 320 MHz, 540 MHz, 640 MHz, 1080 MHz, and 2160 MHz. The bandwidths used by the communication device 100 are not limited to these and may be, for example, 240 MHz, 4 MHz, etc. The IEEE 802.11 series standards specify a frequency channel using a 20 MHz bandwidth as a basic channel in frequency bands such as the 2.4 GHz, 5 GHz, and 6 GHz bands. This standard also defines multiple available channels in each of the 2.4 GHz, 5 GHz, and 6 GHz frequency bands. This standard allows the communication device 100 to use a channel in combination with an adjacent channel. This use of a channel in combination with an adjacent channel may be referred to as channel bonding.

[0014] The IEEE 802.11 series of standards prescribes an OFDMA function that divides one channel into multiple resource units (RUs) on the frequency axis and performs multiple access. OFDMA is an abbreviation for Orthogonal Frequency Division Multiple Access. For example, when multiple STAs are connected to the AP 101, the AP 101 divides one channel used by the AP 101 into multiple RUs and assigns them to each STA. As an example, when two STAs 102 and 103 are connected to the AP 101, the AP 101 transmits one PPDU using one 20 MHz channel. In this case, the AP 101 places two different RUs on the frequency axis within one PPDU. Each RU may have a bandwidth of 10 MHz. Furthermore, the RUs can be arranged so as not to overlap each other on the frequency axis. AP 101 transmits downlink data to STA 102 and STA 103 using the RUs assigned to STA 102 and STA 103. STA 102 and STA 103 receive data transmitted to their own devices using the RUs assigned to them. For example, STA 102 and STA 103 can identify the RUs assigned to them by referencing information about the RU arrangement and allocation stored in the PPDU preamble. In this way, using the OFDMA function allows AP 101 to transmit data to multiple STAs in parallel. Also, for example, when STAs 102 to 104 transmit uplink data to AP 101, AP 101 first transmits a Trigger frame. The Trigger frame can indicate information about the RU arrangement and allocation for uplink transmission. That is, by referring to the Trigger frame, the STAs 102 to 104 can identify the RU that they should use for uplink transmission, and transmit uplink data using that RU.

[0015] The IEEE 802.11bn standard considers repeated data transmission. For example, the transmitting communication device 100 copies the original portion of data in one wireless frame and repeatedly transmits the data, and the receiving communication device 100 decodes the data using multiple pieces of data, including the copied data, thereby increasing the probability of successful reception. However, constantly transmitting data repeatedly reduces the utilization efficiency of frequency resources. On the other hand, when the AP 101 transmits a control frame such as a trigger frame to instruct the STA 110 to transmit data on the uplink, the STA 110 has no means of recognizing that the data should be repeatedly transmitted, and therefore, the STA 110 may not be able to properly process the data transmission.

[0016] In consideration of these circumstances, the communication device 100 in this embodiment notifies the counterpart communication device 100 (partner device) of information regarding repetition when the communication device 100 desires to transmit a radio frame in which data is repeated on a time axis according to the communication conditions. As an example, the communication device 100 may include information regarding the repetition included in the radio frame to be transmitted in a control frame such as a trigger frame. Meanwhile, the counterpart device receiving the control frame determines whether repeated data should be included in the radio frame to be transmitted, and transmits the radio frame in which data is repeated on a time axis based on the result. After transmitting the control frame, the communication device 100 may receive a radio frame including repeated data from the counterpart device, combine multiple pieces of data, and decode the data. The communication device 100 may also weight the multiple pieces of data based on their respective received powers before combining them. Note that the communication device 100 does not necessarily use all of the received data for decoding. For example, the communication device 100 may measure the received power, etc., of each piece of received data and combine data that exceeds a predetermined threshold. In this manner, according to the present embodiment, when a wireless frame including data repeated on a time axis is transmitted to a partner device, a means for notifying and specifying information related to the repetition is provided, which allows the communication device 100 to flexibly increase reliability by using data repetition according to the communication situation, etc.

[0017] (Device Configuration) FIG. 2 shows an example of the hardware configuration of the communication device 100 (AP 101 and STA 110) in this embodiment. The communication device 100 has a storage unit 201, a control unit 202, a function unit 203, an input unit 204, an output unit 205, a communication unit 206, and an antenna 207. Note that there may be multiple antennas. The storage unit 201 is configured with one or more memories such as ROM and RAM, and stores various information such as computer programs for performing various operations described below and communication parameters for wireless communication. ROM and RAM are abbreviations for Read Only Memory and Random Access Memory, respectively. Note that the storage unit 201 may be a memory such as a ROM, RAM, or other storage medium such as a flexible disk, hard disk, optical disk, magneto-optical disk, CD-ROM, CD-R, magnetic tape, non-volatile memory card, or DVD. Furthermore, the storage unit 201 may include a plurality of memories.

[0018] The control unit 202 is configured with one or more processors, such as a CPU or MPU, and controls the entire communication device 100 by executing a computer program stored in the storage unit 201. The control unit 202 may control the entire communication device 100 in cooperation with the computer program stored in the storage unit 201 and an OS (Operating System). The control unit 202 also generates data and signals (wireless frames) to be transmitted in communication with other communication devices. The CPU stands for Central Processing Unit, and the MPU stands for Micro Processing Unit. The control unit 202 may also include multiple processors, such as multi-core processors, and the multiple processors may control the entire communication device 100. The control unit 202 also controls the functional unit 203 to perform predetermined processes, such as wireless communication, imaging, printing, and projection. The functional unit 203 is hardware that enables the communication device 100 to perform predetermined processes.

[0019] The input unit 204 receives various operations from the user. The output unit 205 outputs various types of information to the user via a monitor screen or a speaker. Here, the output from the output unit 205 may be a display on the monitor screen, an audio output from a speaker, a vibration output, or the like. Note that both the input unit 204 and the output unit 205 may be implemented by a single module, such as a touch panel. Furthermore, the input unit 204 and the output unit 205 may be integrated with the communication device 100 or may be separate units.

[0020] The communication unit 206 controls wireless communication compliant with the IEEE 802.11bn standard. The communication unit 206 may also control wireless communication compliant with other IEEE 802.11 series standards in addition to the IEEE 802.11bn standard, or wired communication such as a wired LAN. The communication unit 206 controls the antenna 207 to transmit and receive signals for wireless communication generated by the control unit 202. If the communication device 100 supports standards such as the NFC standard or Bluetooth in addition to the IEEE 802.11bn standard, the communication unit 206 may control wireless communication compliant with these communication standards. If the communication device 100 can perform wireless communication compliant with multiple communication standards, the communication device 100 may be configured to have separate communication units and antennas compatible with each communication standard. The communication device 100 communicates data such as image data, document data, and video data with a destination communication device via the communication unit 206. The antenna 207 may be configured as a separate unit from the communication unit 206, or may be configured together with the communication unit 206 as a single module.

[0021] The antenna 207 is an antenna capable of communication in the 2.4 GHz band, 5 GHz band, 6 GHz band, etc. In this embodiment, there may be two or more antennas, and if the communication unit 206 is configured with multiple communication units, there may be an antenna corresponding to each communication unit. Alternatively, there may be a different antenna for each frequency band.

[0022] FIG. 3 shows a block diagram of the functional configuration of the communication device 100 (AP 101 and STA 110) according to this embodiment. The communication device 100 may include a wireless LAN control unit 301, a frame generation unit 302, a frame analysis unit 303, a UI control unit 304, and a storage unit 305. The wireless LAN control unit 301 controls the communication unit 206 and the antenna 207 for transmitting and receiving wireless signals with other wireless LAN devices. For example, the wireless LAN control unit 301 cooperates with the frame generation unit 302 and the frame analysis unit 303 to control wireless frame communication in accordance with the IEEE 802.11 standard series. When the wireless LAN control unit 301 is implemented by the control unit 202, the wireless LAN control unit 301 may determine whether data needs to be repeated on the time axis and the number of repetitions. The wireless LAN control unit 301 may also notify the frame generation unit 302 of information regarding the determined data repetition and instruct the frame generation unit 302 to generate a control frame based on that information. The wireless LAN control unit 301 may also perform control to notify the communication device of the other end of the communication chain of specific information for specifying whether or not data is repeated on the time axis in the wireless frame to be transmitted by the other end of the communication chain, the number of repetitions, etc. The specific information regarding repetition may be, for example, information that the wireless frame includes repeated data, the number of repetitions included, the total number including the original, and information that identifies each repeated data.

[0023] The frame generation unit 302 generates wireless frames including MAC frames such as management frames, control frames, and data frames. MAC frames are also called MAC Protocol Data Units (MPDUs) or Aggregate MAC Protocol Data Units (A-MPDUs). Wireless frames consist of a preamble field and a data field. MAC frames such as management frames, control frames, and data frames are stored in the data field. The content of wireless control by each MAC frame generated by the frame generation unit 302 may be restricted by settings stored in the storage unit 305. The frame generation unit 302 may accept settings from a user via the UI control unit 304. The wireless frames generated by the frame generation unit 302 are sent to the wireless LAN control unit 301 and can be transmitted to the outside via the communication unit 206 or the antenna 207.

[0024] The frame analysis unit 303 analyzes wireless frames received through cooperation between the communication unit 206, the antenna 207, and the wireless LAN control unit 301. When analyzing wireless frames, the frame analysis unit 303 can determine the analysis method based on the settings stored in the storage unit 305. The frame analysis unit 303 analyzes the received control frame and can identify whether data is repeated on the time axis in the RU assigned to the device itself, the number of repetitions, etc.

[0025] The UI control unit 304 is configured to include hardware related to a user interface, such as a touch panel or buttons, for accepting operations by a user (not shown) on the AP 101 or the STA 110, and a program for controlling these. The UI control unit 304 also has a function for presenting information, such as displaying images or outputting audio, to the user.

[0026] The storage unit 305 is a storage device that can be configured with ROM, RAM, etc., for storing programs and data that the communication device operates on.

[0027] (Frame Format) Figure 4 shows an example of a radio frame containing data repeated on the time axis, used by the communication device 100 in this embodiment. The AP 101 transmits a trigger frame (410) containing information regarding repetition, which is used by the STA 110 to transmit a radio frame containing data repeated on the time axis. The radio frame transmitted by the STA 110 is also referred to as a TB (Trigger Based) PPDU or UHR TB PPDU. This TB PPDU is a PPDU transmitted by each STA 110 and may include a preamble 411, STA 110 data (412-417) transmitted in RUs separated on the frequency axis, and PEs (418, 419). PE stands for Packet Extension, and is a field that provides the AP 101, which receives the TB PPDU, with time to process the TB PPDU. Instead of PE, a Signal Extension or Padding field may be stored. For example, suppose an RU divided into three on the frequency axis is assigned to STAs 102 to 104 from the top. In this case, for example, the TB PPDU transmitted by STA 102 includes a preamble 411, original data 412, two repeated pieces of data (data 413 and data 414), and a PE 418, and the same data is transmitted three times on the time axis. Also, the TB PPDU transmitted by STA 103 includes only the preamble 411 and original data 415 that does not include repeated data. For example, the TB PPDU transmitted by STA 104 includes a preamble 411, original data 416, one repeated piece of data (data 417), and a PE 419, and the same data is transmitted twice on the time axis.

[0028] 5 shows an example of the format of a Trigger frame used by the communication device 100 in this embodiment. As described above, the AP 101 may use the Trigger frame to notify the STA 110 of allocation information of the RU allocated to it. For example, the Trigger frame is a Basic Trigger frame. The Trigger frame may also be a frame that extends the Basic Trigger frame for standards after IEEE 802.11bn. The Trigger frame includes a Frame Control field 501, a Duration field 502, an RA field 503, and a TA field 504. The Trigger frame also includes a Common Info field 505, a User Info List field 506, a Padding field 507, and an FCS field 508. The Frame Control field 501 indicates the type of frame. The Frame Control field 501 includes a Type subfield and a Subtype subfield. For example, setting the value of "01" in the Type subfield can indicate that this frame is a Control frame. Also, setting the value of "0010" in the Subtype subfield can indicate that this frame is a Trigger frame. The Duration field 502 can be set with the estimated time required for exchanging data and an acknowledgment. The RA field 503 can be set with the MAC address of the communication device that is the destination of this frame. Note that in the case of a Basic Trigger frame, a broadcast address can be set in the RA field 503.

[0029] Note that RA stands for Receiver Address. The TA field 504 can store the MAC address of the communication device that is the sender of this frame. In the case of a Basic Trigger frame, the MAC address or BSSID of the AP 101 can be set in the TA field 504. Note that TA stands for Transmitter Address. The Common Info field 505 includes information that is commonly used for the STAs 110 that receive this frame. The User Info List field 506 includes one or more User Info fields 509. Each of the User Info fields 509 can be used to notify user information (information for each STA) that should receive this frame. For example, the User Info field 509 may include information identifying a communication device with which the TXOP set by this frame is shared, information indicating the duration of the TXOP, information for identifying the bandwidth to be used, information regarding the transmission conditions of the communication device transmitting the TB PPDU, etc. The User Info List field 506 may include one Special User Info field. The Special User Info field may include shared information not included in the Common Info field. The Special User Info field may be omitted if there is no corresponding shared information. The Padding field 507 may include padding data. The FCS field 508 may include information used by the STA to check whether this frame was received successfully.

[0030] The AP 101 may notify the STA 110 of the allocation of an RU using the User Info field 509. The User Info field 509 may include an AID12 subfield 510, an RU Allocation subfield 511, a UL FEC Coding Type subfield 512, and a UL UHR-MCS subfield 513. The User Info field 509 may also include a Repetition subfield 514 and a Number of Repetition subfield 515, which are information regarding data repetition. The User Info field 509 may also include an SS Allocation subfield 516 and a UL Target Receive Power subfield 517. Furthermore, the User Info field 509 may include a PS160 subfield 518, a DRU subfield 519, and a Trigger Dependent User Info subfield 520. The AID12 subfield 510 is set with information identifying the STA 110 that is the target of this User Info field 509. For example, an AID assigned to the target STA 110 may be set. The AID is an identifier assigned to the STA 110 when the AP 101 and the STA 110 establish a connection, and the AID is assigned so that the STA 110 can be uniquely identified. AID is an abbreviation for Association Identifier. This subfield allows the STA 110 to recognize that the User Info field 509 includes information targeted at the STA 110. The RU Allocation subfield 511 indicates the RU allocated to the STA 110 that is the target of this User Info field 509. For example, the RU Allocation subfield 511 may include information indicating an RU size and an RU index. For example, the RU Allocation subfield 511 may indicate a combination of the RU size and the RU index in decimal notation. The UL FEC Coding Type subfield 513 indicates the type of coding used for data communication.The UL UHR-MCS subfield 513 indicates the MCS used for data transmitted in the assigned RU. MCS is an abbreviation for Modulation and Coding Scheme. For example, if 32 types of MCS are to be identified, the UL UHR-MCS subfield 513 is composed of 5 bits. The Repetition subfield 514 indicates whether data is to be repeatedly transmitted on the time axis in the assigned RU. For example, a value of 0 in the Repetition subfield 514 may indicate that data is not repeated, and a value of 1 may indicate that data is repeated. The Repetition subfield may be named differently, for example, it may be named the Replication subfield. The Number of Repetition subfield 515 indicates the number of repetitions on the time axis of data to be transmitted in the assigned RU. For example, if the value of the Number of Repetition subfield 515 is 3, this indicates that the TB PPDU transmitted in the assigned RU contains three repetitions of data. In other words, in this case, the TB PPDU contains four identical pieces of data, including the original (source) data and the three replicated repetitions of the data. When the number of repetitions is specified as 0 to 7, the number of bits in the Number of Repetition subfield 515 may be 3 bits, or 4 bits or more if a larger number of repetitions is required, or 2 bits or less if a smaller number of repetitions is sufficient. The Number of Repetition subfield may also be named differently, such as the Number of Replication subfield. If the number of repetitions specified in the Number of Repetition subfield 515 is 1 or greater, the value of the Repetition subfield 514 is set to 1. The SS Allocation subfield 516 indicates the number of spatial streams to be used by the STA 110 targeted by this User Info field 509, etc.The UL Target Receive Power subfield 517 indicates the received power expected at the antenna of the AP 101. The PS 160 subfield 518 may be used to indicate the band of the allocated RU. For example, the PS 160 subfield 518 may be used in conjunction with the RU Allocation subfield 511 to indicate the band allocated to the STA 110. The Trigger Dependent User Info subfield 520 is an optional field provided depending on the type of Trigger frame.

[0031] The DRU subfield 519 indicates whether or not a DRU (Distributed Tone Resource Unit) will be used in the ODFMA communication following this Trigger frame. For example, the AP 101 may indicate that OFDMA communication using a DRU will be performed by setting the value of this subfield to a specific value. Furthermore, the AP 101 may indicate that OFDMA communication using a Regular RU will be performed by not setting the value of this subfield to a specific value. An RU configured with multiple subcarriers arranged contiguously on the frequency axis is called a Regular RU, and an RU configured with multiple subcarriers arranged distributed on the frequency axis is called a DRU. Note that the contents of the User Info field 509 and the like are merely examples and are not limited thereto. For example, the UL UHR-MCS subfield may be 6 bits or more.

[0032] The arrangement of the subfields that make up the User Info field is not limited to the example in Figure 5, and they may be arranged in a different order. The User Info field does not need to include all of the subfields shown in Figure 5, and may include only some of the subfields. The User Info field may also include subfields different from those shown in Figure 5.

[0033] (Processing Flow) Next, the processing flow executed by the AP 101 and the STA 110 as described above will be described using Figures 6A, 6B, and 7. Figures 6A and 6B show an example of the operation when the AP 101 transmits a Trigger frame to the STA 110 and receives a TB PPDU including data repeated on the time axis from the STA 110. Figure 7 shows an example of the operation when the STA 110 receives a Trigger frame from the AP 101 and transmits a TB PPDU including data repeated on the time axis to the AP 101. Each process shown in the flowcharts of Figures 6A, 6B, and 7 is executed by the processor of the control unit 202 of the AP 101 or the STA 110 executing a computer program stored in the storage unit 201. 6A, 6B, and 7 are realized by the processor of the control unit 202 of each communication device in cooperation with the communication unit 206, the ASIC, DSP, FPGA, etc. of the control unit 202. When clearly indicating the subject of processing, the functional unit described in FIGS. 2 and 3 will be used as the subject.

[0034] First, the operation of transmitting a Trigger frame by AP 101 will be described using Figure 6A. For example, the control unit 202 in AP 101 performs the transmission operation in cooperation with other functional units. AP 101 first determines the STA 110 to which it will transmit a TB PPDU (S601). For example, when transmitting a TB PPDU as shown in Figure 4, three STAs (STA102 to STA104) will be determined. AP 101 may determine the STA 110 to which it will transmit a TB PPDU based on information about the amount of transmission buffer space in STA 110, which is notified to AP 101 in advance by STA 110.

[0035] Next, the AP 101 determines whether the User Info fields of all the STAs determined in S601 have been set (S602). The User Info fields are set in order to generate a Trigger frame to be transmitted by the AP 101.

[0036] If the AP 101 determines that the User Info field of all STAs has not been set (NO in S602), it selects a STA whose User Info field has not been set (S603).The AP 101 then acquires the communication quality of communication with the selected STA (S604).The communication quality may be determined using the received signal strength indicator (RSSI) or signal-to-noise ratio (SNR) from the selected STA.

[0037] Next, based on the communication quality obtained in S604, AP 101 determines whether the data included in the TB PPDU needs to be repeated on the time axis (S605). For example, AP 101 may determine that data needs to be repeated if the communication quality is below a predetermined threshold. For example, AP 101 may use the communication quality measured in past communications, or may estimate and use the communication quality for future communications. When estimating the communication quality for future communications, an inference result can be obtained by inputting the measured communication quality into a trained model obtained by learning using known supervised learning, deep learning, or the like. In this case, AP 101 may determine whether data needs to be repeated based on the probability obtained as the inference result.

[0038] When the AP 101 determines that data repetition is necessary (YES in S605), it may set a repetition number of 1 or more according to the communication quality in the Number of Repetition subfield of the User Info field of the Trigger frame (S606). For example, the AP 101 may determine the number of data repetitions so that the probability of success when decoding using multiple pieces of data exceeds a predetermined threshold. As an example, the AP 101 determines the number of repetitions required for the SNR to exceed a predetermined threshold. Note that the method by which the AP 101 determines the number of data repetitions is not limited to this. For example, the AP 101 may calculate RSSI using received signals from STAs and determine the number of repetitions required for the sum of the RSSIs to exceed a predetermined threshold. Additionally, the AP 101 may indicate that repetition is being performed by setting the Repetition subfield of the User Info field of the Trigger frame to 1.

[0039] If the AP 101 determines that data repetition is not necessary (NO in S605), it may set 0 to the Number of Repetition subfield of the User Info field of the Trigger frame (S607).In addition, it may set 0 to the Repetition subfield of the User Info field of the Trigger frame to indicate that no repetition is being performed.

[0040] Next, the AP 101 appropriately sets the values ​​of other subfields included in the User Info field of the selected STA (S608). For example, the UL FEC Coding Type subfield and the UL UHR-MCS subfield may be set based on the communication quality acquired in S604. After that, the process returns to S602, and if there are any STAs remaining that have not set the User Info field, the AP 101 selects the STA and continues the setting process.

[0041] If AP101 determines that the User Info fields of all STAs have been set (YES in S602), it uses frame generation unit 302 to appropriately set the other fields of the Trigger frame, generates a Trigger frame, transmits it (S609), and terminates the processing.

[0042] Next, referring to FIG. 6B , the operation of AP 101 when receiving a TB PPDU from STA 110 after transmitting a Trigger frame will be described. For example, the control unit 202 in AP 101 performs the receiving operation in cooperation with other functional units. First, AP 101 receives TB PPDUs from all STAs specified in the Trigger frame and determines whether the data included in the TB PPDUs has been decoded (S610). If AP 101 determines that the TB PPDU data from all STAs has not been decoded (NO in S610), AP 101 acquires the TB PPDU transmitted by the specific STA specified in the Trigger frame (S611). Then, AP 101 determines whether the acquired TB PPDU contains data repeated on the time axis (S612). For example, AP101 can determine whether a Trigger frame contains repeated data based on whether the value of the Repetition subfield in the User Info field of a specific STA is set to 1 or whether the value of the Number of Repetition subfield is set to 1 or more.

[0043] If the AP 101 determines that the TB PPDU contains repeated data (YES in S612), it acquires the data contained in the TB PPDU sequentially from the beginning (S613) and performs processing for decoding using the multiple pieces of data. First, the AP 101 determines the reception quality of the acquired data (S614). For example, the AP 101 measures the RSSI and SNR of the data using the frame analysis unit 303, and may determine that the reception quality is acceptable if the measurement result is equal to or greater than a predetermined threshold. If the reception quality of the data is acceptable (YES in S614), the AP 101 stores the data in the storage unit 305 as a combination target (S615). On the other hand, if the reception quality of the data is unacceptable (NO in S614), the STA 102 does not include the data in the combination target (S616). In this case, the data is not stored in the storage unit 305. The AP 101 may discard the data. The AP 101 determines whether it has acquired the data for the number of repetitions (S618). If it has not acquired all the data (NO in S618), it returns to S613, acquires the next data included in the TB PPDU, and continues processing. The AP 101 may make this determination, for example, based on whether it has acquired the number of data set in the Number of Repetition subfield of the User Info field of the Trigger frame. On the other hand, if it has acquired the data for the number of repetitions (YES in S618), it decodes the data using one or more data stored in the storage unit 305 (S619). For example, the AP 101 may combine multiple pieces of data and decode the data. The AP 101 may also combine the received multiple pieces of data after weighting them based on their respective reception powers. On the other hand, if it is determined in S612 that the received TB PPDU does not contain data repeated on the time axis (NO in S612), AP 101 decodes the data independently and stores it in memory unit 305 (S617).

[0044] In S614 to S616, instead of including data with unacceptable reception quality in the combination, AP 101 may store each piece of data together with its reception quality in storage unit 305. Then, in S619, each piece of data stored in storage unit 305 may be subjected to processing such as weighting and interference removal based on the reception quality before being used for combination. By performing processing based on reception quality before using each piece of data for decoding processing, it becomes possible to effectively utilize received signals.

[0045] Next, using FIG. 7, the operation when STA 110 receives a Trigger frame from AP 101 and transmits a TB PPDU including data repeated on the time axis to AP 101 will be described. First, STA 110 receives the Trigger frame transmitted from AP 101 via communication unit 206 (S701). Next, STA 110 uses frame analysis unit 303 to analyze the AID12 subfield included in the User Info field of the Trigger frame and determines whether a value matching its own AID is included (S702). If STA 110 determines that a value matching its own AID is included (YES in S702), STA 110 determines whether the User Info field includes information indicating that the data repeated on the time axis needs to be included in the TB PPDU. For example, the STA 110 may determine whether data repetition is necessary based on whether the value of the Repetition subfield in the User Info field is set to 1 or whether the value of the Number of Repetition subfield is set to 1 or greater. If it is determined that the User Info field contains information indicating that data repetition is necessary (YES in S703), the STA 110 replicates the data for the number of times specified in the User Info field (S704). The number of replications may be specified by the Number of Repetition subfield included in the User Info field. On the other hand, if it is determined that the User Info field does not contain information indicating that data repetition is necessary (NO in S703), the STA 110 does not replicate the data (S705). Finally, the STA 110 uses the RU assigned in the Trigger frame to generate a TB PPDU containing the original data and, if necessary, replicated data, and transmits the TB PPDU to the AP 101 (S706).

[0046] If STA110 determines that the AID12 subfield contained in the User Info field of the Trigger frame does not contain a value that matches its own AID (NO in S702), it determines that an RU cannot be allocated and terminates processing without transmitting a TB PPDU.

[0047] As described above, in this embodiment, the AP 101 determines whether or not to repeat data in the TB PPDU on the time axis and the number of repetitions based on factors such as the communication quality with the STA 110, and notifies the STA 110 of this determination in a Trigger frame. The STA 110 then determines whether or not to repeat data included in the TB PPDU on the time axis based on the information on whether or not to repeat data and the number of repetitions included in the received Trigger frame. The AP 101 then decodes the data using the repeated data included in the TB PPDU transmitted from the STA 110. This enables the data to be decoded with a higher probability using the repeated data.

[0048] (Variation 1) Fig. 8 shows another example of the format of the Trigger frame. The example of Fig. 5 shows an example in which one User Info field is used to indicate to one STA 110 that repeated data is included in the TB PPDU. Fig. 8 shows an example in which multiple User Info fields are used to indicate that repeated data is included in the TB PPDU. For example, if it is desired to have STA 110 transmit the original data and one repeated piece of data, two User Info fields (801, 802) are used.

[0049] Each User Info field includes a Repetition subfield 811, a Number of Repetition subfield 812, and a Repetition ID 813 subfield. In FIG. 8, the subfields other than the Repetition ID subfield have the same configuration as the User Info field in FIG. 5, and therefore will not be described here. The Repetition ID subfield 813 is identification information for uniquely identifying data from among the original data and one or more repeated data pieces repeated on the time axis. For example, the User Info field corresponding to the original data 416 in FIG. 4 would be 801, with the Number of Repetition subfield storing a value of 1 and the Repetition ID subfield storing a value of 0. Furthermore, the User Info field corresponding to the first repetition data 417 in FIG. 4 is 802, the Number of Repetition subfield stores a value of 1, and the Repetition ID subfield stores a value of 1. In other words, the number of User Info fields used is equal to the number of repetitions plus 1, and the Repetition ID subfield of the User Info field corresponding to the Nth repetition stores a value of N, where N is an integer greater than or equal to 1. The Repetition ID subfield may be used to manage received data during the AP 101's TB PPDU reception operation. For example, the AP 101 may store the Repetition ID subfield of the data included in the received TB PPDU in association with the reception quality. Then, when decoding data using multiple pieces of data, the AP 101 may identify the data to be used based on the identifier. For example, the AP 101 may store each received data item and its reception quality separately, and create a table that associates the identifier of each data item with its reception quality. Then, when decoding data, the AP 101 may identify data corresponding to reception quality equal to or greater than a predetermined threshold based on the table. This configuration may improve the efficiency of the management and decoding process of data stored in the AP 101.

[0050] (Variation 2) Instead of notifying information regarding data repetition using the Repetition subfield or the Number of Repetition subfield of the User Info field included in the Trigger frame, the AP 101 may notify information regarding data repetition using the UL UHR-MCS subfield included in the User Info field. Table 1 shows an example of notifying the STA 110 of information regarding data repetition using the UL UHR-MCS subfield.

[0051]

[0052] Generally, the MCS subfield is used to indicate the combination of modulation scheme and coding rate used in communication. In Table 1, in addition to the modulation scheme and coding rate, a value of the UL UHR-MCS subfield is set to indicate the number of repetitions of data included in the TB PPDU. For example, in Table 1, if the value of the UL UHR-MCS subfield is 16, this indicates that the TB PPDU corresponding to the User Info field including this UL UHR-MCS subfield transmits two identical data sets, including the original data and one repeated data, using BPSK modulation and coding rate 1 / 2. If the value of the UL UHR-MCS subfield is 17, this indicates that two repeated data sets are transmitted, and if the value of the UL UHR-MCS subfield is 18, this indicates that three repeated data sets are transmitted. Furthermore, when the value of the UL UHR-MCS subfield is 19 to 21, dual carrier modulation, which repeats data on the frequency axis to transmit the same data twice, is combined with data repetition on the time axis. For example, when the value of the UL UHR-MCS subfield is 19, in addition to dual carrier modulation, one repeated piece of data is transmitted on the time axis, so that the same data is transmitted four times by combining the frequency axis and the time axis. The values ​​of the UL UHR-MCS subfield and the correspondence of each parameter in Table 1 are merely examples and are not limited thereto. For example, a parameter set different from the parameter set shown in Table 1 may be associated with each of the values ​​of the UL UHR-MCS subfield shown in Table 1. In this way, information regarding repeated data is notified to STA 110 using the UL UHR-MCS subfield, so that information necessary for processing the repeated data can be notified to STA 110 without making any changes to the previous frame format, such as adding a Repetition subfield or a Number of Repetition subfield.

[0053] The AP 101 may transmit the Trigger frame by an operation similar to that described above in the description of Figures 6A and 6B. In this example, as described above, the AP 101 generates a Trigger frame that includes a UL UHR-MCS subfield indicating whether the corresponding data is repeated data or the number of repetitions, instead of the Repetition subfield or the Number of Repetition subfield. The STA 110 may obtain information regarding the repeated data from the received Trigger frame by an operation similar to that described above in the description of Figure 7, and transmit a TB PPDU including the repeated data. The AP 101 that receives the TB PPDU may then decode the data using the repeated data included in the TB PPDU.

[0054] As described above, the communication device 100 according to the present embodiment can notify the other device of information regarding repetition when the other device wishes to transmit a wireless frame in which data is repeated on the time axis according to the communication conditions. Based on this information, the other device determines whether or not to include repeated data in the wireless frame to be transmitted, and based on the result, can transmit the wireless frame in which data is repeated on the time axis. This enables the communication device to flexibly use data repetition according to the communication conditions, etc., to improve the reliability of communication.

[0055] The present invention can also be realized by supplying a program that realizes one or more of the functions of the above-described embodiments to a system or device via a network or a storage medium, and having one or more processors in the computer of the system or device read and execute the program.The present invention can also be realized by a circuit (e.g., an ASIC) that realizes one or more of the functions.

[0056] The invention is not limited to the above-described embodiments, and various changes and modifications can be made without departing from the spirit and scope of the invention.

[0057] This application claims priority based on Japanese Patent Application No. 2024-116281, filed July 19, 2024, the entire contents of which are incorporated herein by reference.

[0058] 101 AP 102 STA 301 Wireless LAN control unit 302 Frame generation unit 303 Frame analysis unit 304 UI ​​control unit 305 Storage unit

Claims

1. A communications device that performs communications in accordance with the IEEE 802.11 standard series, characterized by having: a transmitting means for transmitting to a remote device a control frame containing information regarding repetition for the remote device to transmit a wireless frame containing data repeated on a time axis; and a receiving means for receiving the wireless frame from the remote device.

2. The communication device according to claim 1, wherein the control frame is a trigger frame.

3. The communication device according to claim 2, wherein the Trigger frame includes a field indicating user information, and the field indicating user information includes information regarding the repetition.

4. A communication device according to any one of claims 1 to 3, characterized in that the information relating to repetition includes information indicating whether or not data is to be repeated on the time axis.

5. A communication device according to any one of claims 1 to 4, characterized in that the information relating to repetition includes information indicating the number of repetitions of data on the time axis.

6. A communication device according to any one of claims 1 to 5, characterized in that the information relating to repetition includes information for identifying the order of repetition of data on the time axis.

7. The communication device according to claim 3, wherein the field indicating the user information includes a field indicating a modulation and coding scheme (MCS), and the field indicating the MCS includes a value identifying the number of repetitions of data on the time axis.

8. A communication device according to any one of claims 1 to 7, characterized in that it comprises a decoding means for synthesizing at least two pieces of repetitive data contained in the radio frame received by the receiving means and decoding the data.

9. A communication device according to any one of claims 1 to 8, wherein the communication device is an access point (AP) device, and the other device is a non-AP station device.

10. A communication device that performs communication in accordance with the IEEE 802.11 standard series, characterized by having: a receiving means for receiving from a remote device a control frame containing information regarding repetition for the communication device to transmit a wireless frame containing data repeated on a time axis; and a transmitting means for transmitting the wireless frame to the remote device.

11. The communication device according to claim 10, wherein the control frame is a trigger frame.

12. The communication device according to claim 11, wherein the Trigger frame includes a field indicating user information, and the field indicating user information includes information regarding the repetition.

13. A communication device according to any one of claims 10 to 12, characterized in that the information relating to repetition includes information indicating whether or not data is to be repeated on the time axis.

14. A communication device according to any one of claims 10 to 13, characterized in that the information relating to repetition includes information indicating the number of repetitions of data on the time axis.

15. A communication device according to any one of claims 10 to 14, characterized in that the information relating to repetition includes information for identifying the order of repetition of data on the time axis.

16. The communication device according to claim 12, wherein the field indicating the user information includes a field indicating a modulation and coding scheme (MCS), and the field indicating the MCS includes a value identifying the number of repetitions of data on the time axis.

17. The communication device according to any one of claims 10 to 16, wherein the counterpart device is an access point (AP) device, and the communication device is a non-AP station device.

18. A communication method for a communication device that performs communication in accordance with the IEEE 802.11 standard series, comprising: a transmitting step of transmitting a control frame containing information regarding repetition to a remote device, so that the remote device can transmit a wireless frame containing data repeated on a time axis; and a receiving step of receiving the wireless frame from the remote device.

19. A communication method for a communication device that performs communication in accordance with the IEEE 802.11 standard series, comprising: a receiving step of receiving from a remote device a control frame containing information regarding repetition for the communication device to transmit a wireless frame containing data repeated on a time axis; and a transmitting step of transmitting the wireless frame to the remote device.

20. A program for causing a computer to operate as a communication device according to any one of claims 1 to 9.

21. A program for causing a computer to operate as a communication device according to any one of claims 10 to 17.

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