Communication device, control method, and program

Abstract

This technology provides a way to properly perform communication using PPDU (Physical Layer Protocol Data Unit) for long-distance communication. [Solution] The communication device is a communication device compliant with the IEEE 802.11 standard series and has a transmission means for transmitting a PPDU (Physical layer Protocol Data Unit) having a preamble that includes a first U-SIG (Universal Signal) field, a second U-SIG field containing the same data as the first U-SIG field, a first UHR-SIG (Ultra High Reliability Signal) field, and a second UHR-SIG field containing the same data as the first UHR-SIG field, wherein the first U-SIG field and the second U-SIG field are modulated using different modulation schemes.

Description

【Technical Field】 【0001】 The present disclosure relates to a communication device, a control method, and a program. 【Background Art】 【0002】 With the increase in the amount of data communicated in recent years, the development of communication technologies such as wireless LAN (Local Area Network) has been promoted. As the main communication standards for wireless LAN, the IEEE (Institute of Electrical and Electronics Engineers) 802.11 standard series is known. The IEEE 802.11 standard series includes standards such as IEEE 802.11a / b / g / n / ac / ax / be. For further improvement in communication reliability, the development of the IEEE 802.11bn standard is underway as a successor standard to the IEEE 802.11be standard. In the IEEE 802.11 WG (Working Group) that formulates the IEEE 802.11bn standard, in the UHR SG, the goals and scope of study of this standard are determined, and in TGbn, the details of the technology to be included in this standard are planned to be defined. Note that UHR SG is an abbreviation for Ultra High Reliability Study Group. Also, TGbn is an abbreviation for Task Group bn. The name UHR was provided for convenience based on the goals to be achieved by the successor standard and the features that are the highlights of the standard, and it may become another name when the standard formulation is completed. Similarly, the name IEEE 802.11bn may become another name when the standard formulation is completed. On the other hand, this specification and the appended claims are essentially applicable to all successor standards that are successor standards to the 802.11be standard. 【0003】 One of the candidate technologies included in the IEEE 802.11bn standard is communication using PPDU for long-distance communication. PPDU is an abbreviation for PLCP Protocol Data Unit, and PLCP is an abbreviation for Physical Layer Convergence Protocol. A new type of PPDU called ELR (Enhanced Long Range) PPDU is being considered for long-distance communication (see Non-Patent Document 1). Note that PLCP Protocol Data Unit is an example of Physical Layer (PHY) Protocol Data Unit, and PPDU is also an abbreviation for Physical Layer Protocol Data Unit. [Prior art documents] [Non-patent literature] 【0004】 [Non-Patent Document 1] Jianhan Liu et al., “Design Targets and Considerations for Enhanced Long Range (IEEE 802.11-24 / 0873r2),” IEEE802.11, 2024. [Overview of the project] [Problems that the invention aims to solve] 【0005】 However, the details of the ELR PPDU format are not specified and are not clearly defined. If this format is not clearly defined, misunderstandings may occur between communication devices in a wireless LAN, potentially preventing proper communication using PPDU for long-distance communication. 【0006】 One aspect of this disclosure, in view of the above, aims to provide a technology for appropriately performing communication using a PPDU for long-distance communication. [Means for solving the problem] 【0007】 A communication device according to one aspect of the present disclosure is a communication device compliant with the IEEE 802.11 standard series, and has a transmitting means for transmitting a PPDU (Physical layer Protocol Data Unit) having a preamble including a first U-SIG (Universal Signal) field, a second U-SIG field containing the same data as the first U-SIG field, a first UHR-SIG (Ultra High Reliability Signal) field, and a second UHR-SIG field containing the same data as the first UHR-SIG field, wherein the first U-SIG field and the second U-SIG field are modulated with different modulation schemes. [Effects of the Invention] 【0008】 According to one aspect of this disclosure, communication using a PPDU for long-distance communication can be performed appropriately. [Brief explanation of the drawing] 【0009】 [Figure 1] A diagram showing an example configuration of a wireless communication system according to the embodiment. [Figure 2] A block diagram showing an example of the functional configuration of a communication device according to this embodiment. [Figure 3] A diagram showing an example of the hardware configuration of a communication device according to the embodiment. [Figure 4] A flowchart illustrating an example of communication processing performed by a communication device according to an embodiment. [Figure 5] A diagram showing an example of a frame format used to notify whether or not a PPDU for long-distance communication can be transmitted or received, according to an embodiment. [Figure 6] A diagram showing an example of a frame format for PPDU for long-distance communication according to the embodiment. [Figure 7] A diagram illustrating an example of the relationship between the value of the UHR-SIG MCS field and communication parameters according to the embodiment. [Modes for carrying out the invention] 【0010】 The embodiments will be described in detail below with reference to the attached drawings. Note that the following embodiments do not limit the scope of the claims. While the embodiments describe multiple features, not all of these features are essential to this disclosure, and the features may be combined in any way. Furthermore, in the attached drawings, identical or similar configurations are given the same reference numerals, and redundant descriptions are omitted. 【0011】 <Embodiment> (Network configuration) Figure 1 is a diagram showing an example configuration of a wireless communication system according to this embodiment. Figure 1 shows an example of the network configuration related to this embodiment. Figure 1 shows a configuration including one AP (Access Point) 102 and three STAs (Stations) 103, 104, and 105 as a (wireless) communication device that performs wireless LAN communication compliant with the IEEE 802.11bn standard. STAs are sometimes called non-AP STAs. 【0012】 As shown in Figure 1, the network formed by AP102 is indicated by circle 101. STA103-105 can transmit and receive signals transmitted and received by AP102. In this embodiment, AP102 and STA103-105 are sometimes collectively referred to as the communication device 100. Note that the configuration shown in Figure 1 is just one example, and other communication devices performing wireless LAN communication may exist in a wider area, for example. 【0013】 In this embodiment, AP102 is configured to perform a communication method compliant with the IEEE 802.11bn standard. The IEEE 802.11bn standard is the successor to the IEEE 802.11be standard, and its main features include functions that realize highly reliable communication, low latency communication, and improved throughput when communication traffic is congested. The wireless frame used in a communication method compliant with this standard may be called a UHR (Ultra High Reliability) PPDU. PPDU is an abbreviation for PLCP Protocol Data Unit, and PLCP is an abbreviation for Physical Layer Convergence Protocol. 【0014】 Note that the names UHR and IEEE802.11bn may be changed to different names once the standards are finalized. Also note that this specification and the claims attached herein are applicable to communication devices using all successor standards to IEEE802.11be. Furthermore, communication device 100 may support at least one of the legacy standards that predate the IEEE802.11bn standard. Legacy standards include, for example, the IEEE802.11a / b / g / n / ac / ax / be standards. Communication device 100 may also support other communication standards such as Bluetooth®, NFC, Bluetooth LE (Low Energy), UWB, ZigBee®, and MBOA. Note that NFC is an abbreviation for Near Field Communication, UWB is an abbreviation for Ultra Wide Band, and MBOA is an abbreviation for Multi Band OFDM Alliance. UWB includes wireless USB, wireless 1394, WiNET, etc. The communication device 100 can also be configured to support wired communication using Ethernet® cables or fiber optic cables. The communication device 100 can also be configured to support cellular wireless communication such as 5G and LTE (Long Term Evolution). 【0015】 AP102 may be, but is not limited to, a wireless LAN router or a personal computer (PC). AP102 may be an information processing device such as a wireless chip capable of performing wireless communication compliant with the IEEE 802.11bn standard. The communication device 100 may also be an information processing device such as a wireless chip that supports PPDU transmission and reception. In this case, the wireless chip can be configured to perform various controls using hardware circuits within it. It is also possible to configure the wireless chip to perform various processes through the cooperation of a processor such as an ASIP, memory, and hardware circuits within it. ASIP is an abbreviation for Application-specific instruction set processor. 【0016】 Specific examples of STA103-105 include, but are not limited to, cameras, tablets, smartphones, PCs, mobile phones, video cameras, smart glasses, and wearable devices such as HMDs (head-mounted displays). STA103-105 may also be an information processing device such as a wireless chip capable of performing wireless communication compliant with the IEEE 802.11 series standard. Furthermore, STA103-105 may also be an IoT device such as an Internet of Things (IoT) sensor, smart lock, or smart sensor. IoT sensors may include acceleration sensors, light sensors, humidity sensors, etc. 【0017】 The communication device 100 can communicate using wireless signals in frequency bands such as the 2.4 GHz band, 3.6 GHz band, 5 GHz band, 6 GHz band, and the 45 GHz band and 60 GHz band called millimeter waves. The frequency band used by the communication device 100 is not limited to these, and can be, for example, the Sub1GHz band or the like. Also, the communication device 100 can communicate using bandwidths of 20 MHz, 40 MHz, 80 MHz, 160 MHz, 320 MHz, 540 MHz, 640 MHz, 1080 MHz, and 2160 MHz. The bandwidth used by the communication device 100 is not limited to these, and can be, for example, 240 MHz or 4 MHz or the like. In the IEEE802.11 series standards, frequency channels using a bandwidth of 20 MHz are defined as basic channels in frequency bands such as the 2.4 GHz, 5 GHz, and 6 GHz bands. Also, in this standard, a plurality of available channels are defined in each of the 2.4 GHz band, 5 GHz band, and 6 GHz band. Also, in this standard, a certain channel can be used in combination with other adjacent channels. In the present embodiment, using a certain channel in combination with other adjacent channels may be referred to as channel bonding. Also, a bundle of channels formed by one or two or more adjacent channels may be referred to as a communication link (or simply a link). That is, one link formed by two 20 MHz bandwidth channels uses a bandwidth of 40 MHz. Note that the communication device 100 may be an AP MLD (Multi-Link Device) and STA MLD corresponding to Multi-Link that simultaneously establishes a plurality of links for communication. 【0018】 The communication device 100 establishes one or more links between devices to communicate data with other communication devices. For example, STAs 103 - 105 execute a connection procedure with the AP 102 to establish a link with the AP 102. When the connection procedure between STAs 103 - 105 and the AP 102 is completed, a link is established between the devices. By establishing the link, the communication device 100 can access the wireless medium and communicate data and the like with the other communication device. For example, when one link using a bandwidth of 160 MHz is established between devices, the communication device 100 communicates using all or some of the channels constituting the link. A link using a bandwidth of 160 MHz can be configured by bundling eight channels with a bandwidth of 20 MHz. 【0019】 (Configuration of AP and STA) FIG. 2 is a block diagram showing a functional configuration example of the AP 102 and STAs 103 - 105 (communication device 100). As shown in FIG. 2, as an example of their functional configuration, the AP 102 and STAs 103 - 105 have a wireless LAN control unit 201, a wireless frame generation unit 202, a wireless frame processing unit 203, a UI (User Interface) control unit 204, and a memory control unit 205. These functions can be realized, for example, by the control unit 302 described later executing a program stored in the storage unit 301 described later, or by a processing function unit in the communication unit 306 described later. Note that FIG. 2 is a diagram for explaining the main functions in the present embodiment, and other functions are omitted. Therefore, for example, the communication device 100 may naturally have functions for establishing a connection between a normal AP and STA and for communication control, and functions that a communication device generally has. Also, a plurality of functional blocks shown in FIG. 2 may be integrated into one functional block, or one functional block may be divided into a plurality of functional blocks. Also, the names of the functional blocks shown in FIG. 2 are only examples and may be changed. 【0020】 The wireless LAN control unit 201 comprises an antenna and circuit for transmitting and receiving wireless signals with other communication devices, and a program for controlling them. The wireless LAN control unit 201 performs wireless LAN communication control based on frames generated by the wireless frame generation unit 202 in accordance with the IEEE 802.11 standard series. For example, the wireless LAN control unit 201 performs the transmission process of frames generated by the wireless frame generation unit 202 and the reception process of frames transmitted from other communication devices. 【0021】 The wireless frame generation unit 202 generates frames to be transmitted by the wireless LAN control unit 201. For example, the wireless frame generation unit 202 generates frames based on configuration information stored in the storage unit 301 (described later) or user configuration information entered by the user. 【0022】 The wireless frame processing unit 203 interprets the wireless frame received by the wireless LAN control unit 201 and reflects its contents back to the wireless LAN control unit 201. 【0023】 The UI control unit 204 includes hardware related to the user interface, such as a touch panel and buttons, for receiving operations on the AP and STA by users using the AP and STA, as well as programs to control them. The UI control unit 204 also has functions for presenting information to the user, such as displaying images or outputting audio. 【0024】 The memory control unit 205 controls the writing and reading of data to the memory unit 301, which will be described later, such as ROM (Read Only Memory) and RAM (Random Access Memory), where the AP and STA operate and the data are stored. 【0025】 Figure 3 shows an example of the hardware configuration of AP102 and STA103-105 (communication device 100). As shown in Figure 3, AP102 and STA103-105 have, as an example of their hardware configuration, a storage unit 301, a control unit 302, a function unit 303, an input unit 304, an output unit 305, a communication unit 306, and a wireless antenna 307. 【0026】 The storage unit 301 is composed of one or more memories, such as both ROM and RAM, or either one of them, and stores various information such as programs for performing various operations described later, and communication parameters (setting information) for wireless communication. In addition to memories such as ROM and RAM, storage media such as flexible disks, hard disks, SSDs, optical disks, magneto-optical disks, CD-ROMs, CD-Rs, magnetic tapes, non-volatile memory cards, and DVDs may be used as the storage unit 301. SSD is an abbreviation for Solid State Drive. CD-ROM is an abbreviation for Compact Disc Read Only Memory, CD-R is an abbreviation for Compact Disc Recordable, and DVD is an abbreviation for Digital Versatile Disc. 【0027】 The control unit 302 is composed of, for example, one or more processors such as a CPU or MPU, an ASIC (Application-Specific Integrated Circuit), a DSP (Digital Signal Processor), or an FPGA (Field-Programmable Gate Array). CPU is an abbreviation for Central Processing Unit, and MPU is an abbreviation for Micro Processing Unit. The control unit 302 controls the entire device by executing a program stored in the memory unit 301. Alternatively, the control unit 302 may control the device in cooperation with the OS (Operating System) and the program stored in the memory unit 301. 【0028】 Furthermore, the control unit 302 controls the functional unit 303 to perform predetermined processes such as imaging, printing, and projection. The functional unit 303 is hardware for the AP or STA to perform predetermined processes. For example, if the AP or STA is a camera, the functional unit 303 is the imaging unit and performs imaging processing. Also, for example, if the AP or STA is a printer, the functional unit 303 is the printing unit and performs printing processing. Also, for example, if the AP or STA is a projector, the functional unit 303 is the projection unit and performs projection processing. The data processed by the functional unit 303 may be data stored in the storage unit 301, or it may be data communicated with other communication devices via the communication unit 306, which will be described later. 【0029】 The input unit 304 accepts various operations from the user. The output unit 305 provides various outputs to the user. Here, the output from the output unit 305 includes at least one of the following: display on the screen, audio output from a speaker, vibration output, etc. Note that both the input unit 304 and the output unit 305 may be implemented in a single module, such as a touch panel. Furthermore, the input unit 304 and the output unit 305 may be integrated with the AP or STA, respectively, or they may be separate components. 【0030】 The communication unit 306 includes a so-called wireless LAN chip and performs control of wireless communication compliant with the IEEE 802.11 standard series, control of IP communication, etc. In this embodiment, the communication unit 306 can perform processing compliant with at least the IEEE 802.11bn standard. The communication unit 306 is a processing device that generates UHR PPDUs as defined in the IEEE 802.11bn standard, and may also have the function of generating types of PPDUs defined in earlier standards. The communication unit 306 also controls the wireless antenna 307 to transmit and receive wireless signals for wireless communication. The AP and STA communicate content such as image data, document data, and video data with other communication devices via the communication unit 306. 【0031】 The wireless antenna 307 may be physically composed of two or more antennas in order to realize MIMO (Multi-Input and Multi-Output) transmission and reception. The wireless antenna 307 may be configured separately from the communication unit 306, or it may be configured as a single module together with the communication unit 306. The wireless antenna 307 is an antenna capable of communication in the 2.4GHz, 5GHz, 6GHz, 45GHz, and 60GHz bands. In Figure 3, the communication device 100 is shown to have one antenna, but it may have two or more antennas. Alternatively, the communication device 100 may have different antennas for each frequency band. 【0032】 In the example shown in Figure 3, the communication device 100 is configured to have only one communication unit 306, but it is also possible to provide a separate communication unit for each of the multiple wireless antennas. 【0033】 AP102 can be any communication device having the configuration shown in Figures 2 and 3, and may be a so-called AP-dedicated communication device such as a wireless LAN router, or it may be a communication device with AP functionality such as a smartphone, camera, or printer. 【0034】 (Operation of a communication device when it transmits data) Next, the processing flow of the communication device when performing communication using a PPDU for long-distance transmission in this embodiment will be described. 【0035】 Figure 4 is a flowchart showing an example of the process when STA103 performs communication with AP102 using ELR PPDU. The operations shown in this flowchart can be performed in STA103 by the control unit 302 reading and executing a computer program stored in the storage unit 301. 【0036】 In this embodiment, first, a connection is made between AP102 and STA103 (S401). That is, STA103 connects to AP102. Before long-distance communication using ELR PPDU is performed between AP102 and STA103, the transmitting terminal needs to know whether the receiving terminal is in a state where it can receive long-distance transmitted PPDU. In this embodiment, the transmitting terminal is STA103 and the receiving terminal is AP102. 【0037】 AP102 can notify surrounding STAs whether or not it is in a state where it can transmit and receive the PPDU by transmitting a beacon frame to them. The beacon frame includes a signal (information) indicating whether or not it is in a state where it can transmit and receive the ELR PPDU. For example, the beacon frame includes the UHR Operation element shown in Figure 5(a). In this specification, the information indicating whether or not it is in a state where it can transmit the ELR PPDU is called ELR PPDU transmission availability information, and the information indicating whether or not it is in a state where it can receive the ELR PPDU is called ELR PPDU reception availability information. In this specification, the signal (information) indicating whether or not it is in a state where it can transmit and receive the ELR PPDU is called the ELR PPDU transmission / reception availability signal (information) or the ELR PPDU communication availability signal (information). For example, each of the ELR PPDU transmission availability information and the ELR PPDU reception availability information is 1 bit and may take the value "1" or the value "0". A value of "1" indicates that transmission (reception) is possible (transmission (reception) is enabled), and a value of "0" indicates that transmission (reception) is not possible (transmission (reception) is not enabled). The values ​​"1" and "0" may have opposite meanings. 【0038】 The UHR Operation element shown in Figure 5(a) includes an Element ID field 501, a Length field 502, and an Element ID Extension field 503. The UHR Operation element shown in Figure 5(a) also includes a UHR Operation Parameters field 504. 【0039】 The Element ID field 501 and the Element ID Extension field 503 indicate that the element is a UHR Operation element. The values ​​for Element ID field 501 and Element ID Extension field 503 can be any values ​​not used in the IEEE 802.11 standard. For example, Element ID field 501 can be the value "255", and Element ID Extension field 503 can be the value "142". 【0040】 The UHR Operation Parameters field 504 includes the ELR Tx enable at 2.4GHz subfield 505 and the ELR Rx enable at 2.4GHz subfield 506. The UHR Operation Parameters field 504 also includes the ELR Tx enable at 5GHz subfield 507 and the ELR Rx enable at 5GHz subfield 508. The UHR Operation Parameters field 504 also includes the ELR Tx enable at 6GHz subfield 509 and the ELR Rx enable at 6GHz subfield 510. 【0041】 The ELR Tx enable at 2.4GHz subfield 505 indicates whether transmission of ELR PPDUs in the 2.4GHz band is possible. The ELR Rx enable at 2.4GHz subfield 506 indicates whether reception of ELR PPDUs in the 2.4GHz band is possible. The ELR Tx enable at 5GHz subfield 507 indicates whether transmission of ELR PPDUs in the 5GHz band is possible. The ELR Rx enable at 5GHz subfield 508 indicates whether reception of ELR PPDUs in the 5GHz band is possible. The ELR Tx enable at 6GHz subfield 509 indicates whether transmission of ELR PPDUs in the 6GHz band is possible. The ELR Rx enable at 6GHz subfield 510 indicates whether reception of ELR PPDUs in the 6GHz band is possible. 【0042】 The signal indicating whether or not the above ELR communication can be performed may also be included in an element with a different name (for example, an information element). Alternatively, the capability information for ELR communication may be included in an element containing capability information, such as a UHR Capabilities element. 【0043】 The UHR Operation element described above includes information for 2.4GHz, 5GHz, and 6GHz, and communication of the UHR Operation element in a specific communication band allows for the exchange of information for multiple bands. However, the UHR Operation element may also include information only for the band on which it is transmitted. For example, a UHR Operation element transmitted using the 2.4GHz band may include information on whether ELR PPDU transmission is possible and information on whether ELR PPDU reception is possible for the 2.4GHz band. Alternatively, the UHR Operation element may include information on whether transmission and reception are possible for some bands. For example, a communication device that supports the 2.4GHz, 5GHz, and 6GHz bands may transmit a UHR Operation element using the 2.4GHz band that includes information on whether transmission and reception are possible for the 2.4GHz band and information on whether transmission and reception are possible for the 6GHz band. 【0044】 Alternatively, the frame used to establish a connection between AP102 and STA103 may include the aforementioned UHR Operation element. Examples of frames used to establish a connection between AP102 and STA103 include Association request frames and Association response frames. Additionally or alternatively, the aforementioned UHR Operation element may be included in frames such as Probe request frames sent by STA and Probe response frames sent by AP as replies. Furthermore, the aforementioned UHR Operation element may be included in frames such as Reassociation request frames and Reassociation response frames. In this way, the aforementioned UHR Operation element can be included in management frames, including beacon frames. 【0045】 To notify whether ELR PPDU transmission and reception is possible, this information can be included in the A-Control field in the MAC header. An example of a MAC header format for a frame that implements this method is shown in Figure 5(b). 【0046】 The MAC header shown in Figure 5(b) includes the Frame control field 511, the Duration / ID field 512, the Address1 field 513, the Address2 field 514, and the Address3 field 515. The MAC header shown in Figure 5(b) also includes the Sequence Control field 516, the Address4 field 517, the QoS Control field 518, the A-Control field 519, and the FCS field 520. 【0047】 The A-Control field 519 includes the Control ID field 521 and the UHR OM Control field 522. 【0048】 The Control ID field 521 is a field that stores a value indicating the type of the following field, and stores a value indicating that the UHR OM Control field follows. In this embodiment, the Control ID field 521 stores the value "10", but other values ​​may be stored as long as duplication with values ​​specified in legacy standards is avoided. 【0049】 The UHR OM Control field 522 includes subfields 523 and 524 for ELR Tx enable at 2.4GHz and ELR Rx enable at 2.4GHz. The UHR OM Control field 522 also includes subfields 525 and 526 for ELR Tx enable at 5GHz and ELR Rx enable at 5GHz. The UHR OM Control field 522 also includes subfields 527 and 528 for ELR Tx enable at 6GHz. 【0050】 The ELR Tx enable at 2.4GHz subfield 523 indicates whether transmission of ELR PPDUs in the 2.4GHz band is possible. The ELR Rx enable at 2.4GHz subfield 524 indicates whether reception of ELR PPDUs in the 2.4GHz band is possible. The ELR Tx enable at 5GHz subfield 525 indicates whether transmission of ELR PPDUs in the 5GHz band is possible. The ELR Rx enable at 5GHz subfield 526 indicates whether reception of ELR PPDUs in the 5GHz band is possible. The ELR Tx enable at 6GHz subfield 527 indicates whether transmission of ELR PPDUs in the 6GHz band is possible. The ELR Rx enable at 6GHz subfield 528 indicates whether reception of ELR PPDUs in the 6GHz band is possible. 【0051】 The communication device 100 can notify whether or not ELR PPDU can be sent or received by transmitting data frames such as QoS Data frames or QoS Null frames having the MAC header described above. 【0052】 AP102 can notify its communication partner, STA103, whether or not it is in a state where it can send and receive ELR PPDUs, based on the information contained in any of the frames described above. Similarly, STA103 can notify AP102 whether or not it is in a state where it can send and receive ELR PPDUs, using the same method. 【0053】 The ability to send and receive ELR PPDUs may be determined, for example, by the capabilities of the communication device. Furthermore, the ability to send and receive ELR PPDUs may be determined or changed depending on the communication status and environment of the communication device. For example, ELR PPDUs have characteristics such as setting a low communication rate or repeating specific fields in order to improve (extend) the communication distance, and therefore tend to have a longer duration. For this reason, if the BSS (Basic Service Set) to which the communication device belongs is congested, the communication device may decide not to use ELR PPDUs for communication in order to reduce congestion. High BSS congestion occurs, for example, when the throughput is below a predetermined value, when the number of STAs connected to the AP is above a predetermined number, when the wireless resource utilization is above a predetermined value, or a combination of these. In this way, a communication device may change the ELR PPDU transmission / reception status information according to the communication congestion of the BSS to which it belongs, and notify the changed ELR PPDU transmission / reception status information. 【0054】 Furthermore, if other communication methods that extend the communication distance are available, the communication device may decide not to use ELR PPDU. Examples of other available communication methods include: long-distance communication via a third party other than the sender and receiver; transmission at the maximum permissible transmission power or a predetermined value or higher; use of a specific frequency band; or a combination thereof. A third party other than the sender and receiver could be, for example, a relay device (repeater, relay). If the communication device decides not to use ELR PPDU for communication in this manner, it may disable the transmission and reception of ELR PPDU. That is, the communication device may set the ELR PPDU transmission / reception availability information to a value indicating that transmission / reception is not possible (i.e., impossible), and may notify the user of the set ELR PPDU transmission / reception availability information. 【0055】 Returning to the explanation of Figure 4, if STA103 has received the UHR Operation element transmitted by AP102 (Yes in S402), it determines whether AP102 can perform ELR communication (S403). If AP102 can perform ELR communication (Yes in S403), STA103 stores AP102 as a communication device capable of performing communication using ELR PPDU (referred to as an ELR-capable communication device) (S404). 【0056】 On the other hand, if STA103 has not received a UHR Operation element (No in S402), it proceeds to S417. Also, if AP102 is unable to perform ELR communication (No in S403), STA103 proceeds to S417. 【0057】 If the transmit buffer contains data to be transmitted by STA103, that is, if an ELR PPDU should be transmitted (Yes in S405), STA103 generates an ELR PPDU (S406) and transmits the ELR PPDU to the destination communication device (S407). 【0058】 If STA103 receives an Ack (Acknowledgement) frame from the destination communication device (Yes in S408), it processes it as ELR PPDU transmission complete (S409) and proceeds to S405. On the other hand, if STA103 does not receive an Ack frame (Yes in S408), it processes it as ELR PPDU transmission failure (S410) and proceeds to S405. In the event of a transmission failure, STA103 may attempt to transmit (retransmit) up to a certain number of times, or it may terminate transmission as transmission is impossible. 【0059】 If the transmit buffer does not contain the data that STA103 is sending (No in S405), STA103 determines whether it has received the PPDU (S412). 【0060】 If STA103 receives a PPDU (Yes in S412), and the received PPDU is an ELR PPDU (Yes in S413), it processes it as an ELR PPDU (S414) and proceeds to S405. On the other hand, if STA103 does not receive an ELR PPDU (No in S413), it processes it as a PPDU other than an ELR PPDU (S415) and proceeds to S405. 【0061】 If STA103 has not received a PPDU in S412 (No in S412), it proceeds to S405. 【0062】 In S417, STA103 performs a normal transmit / receive flow, which is not long-distance communication. 【0063】 (Wireless frame structure) Next, an example of an ELR PPDU transmitted in this embodiment will be described. Figure 6 shows an example of a frame format for a long-distance communication PPDU (ELR PPDU). 【0064】 The ELR PPDU shown in Figure 6(a) includes the STF (Short Training Field), LTF (Long Training Field), and SIG (Signal) fields. 【0065】 The beginning of the ELR PPDU shown in Figure 6(a) includes L(Legacy)-STF601, L-LTF602, and L-SIG603 to ensure backward compatibility with IEEE 802.11a / b / g / n / ax / be standards. L-LTF602 is placed immediately after L-STF601, and L-SIG603 is placed immediately after L-LTF602. The ELR PPDU shown in Figure 6(a) also includes RL-SIG (Repeated L-SIG)604, which is placed immediately after L-SIG603. RL-SIG604 transmits the content of L-SIG603 repeatedly. RL-SIG604 allows the recipient to recognize that the PPDU conforms to standards from IEEE 802.11ax onwards, and may be omitted in some cases in IEEE 802.11bn. Alternatively, instead of RL-SIG604, a field may be provided to allow the recipient to recognize that it is an IEEE 802.11bn PPDU. The fields of the ELR PPDU do not necessarily have to be in the order shown in Figure 6, and the ELR PPDU may include new fields not shown in Figure 6. 【0066】 The L-STF601 is used for PHY frame signal detection, automatic gain control (AGC), timing detection, and other applications. 【0067】 The L-LTF602 is used for high-precision synchronization of frequency and time, acquisition of propagation channel information (CSI: Channel State Information), and other purposes. 【0068】 In the case of ELR PPDU, a power boost of, for example, 3dB may be applied compared to other types of PPDUs such as L-STF601 and L-LTF602. However, the amount of power boost is not limited to 3dB. Power boosting is expected to improve the SNR (Signal-to-Noise Ratio) in the field and increase the range over which ELR PPDU can be transmitted between the transmitting and receiving terminals. 【0069】 L-SIG603 is used to transmit control information, including data transmission rate and PHY frame length information. Legacy devices conforming to IEEE 802.11a / b / g / n / ax / be standards can decode the various legacy fields mentioned above. 【0070】 The ELR PPDU shown in Figure 6(a) further includes a U-SIG (Universal SIG) field 605, which contains information common to IEEE 802.11be and later standards, and is located immediately after RL-SIG604. The ELR PPDU shown in Figure 6(a) further includes a U-SIG field 606, which follows the U-SIG field 605 and consists of the same data as the U-SIG field 605. Note that the U-SIG field is sometimes simply referred to as U-SIG. 【0071】 Table 1 below shows an example configuration of U-SIG fields 605 and 606. U-SIG fields 605 and 606 are fields that may contain information about the repetition of a subsequent predetermined field. Each U-SIG field (U-SIG fields 605 and 606) consists of a U-SIG1 field and a U-SIG2 field. 【0072】 The U-SIG2 field includes the UHR-SIG MCS field, which indicates the Modulation and coding scheme (MCS) used to modulate the subsequent UHR-SIG field. The UHR-SIG field is sometimes simply referred to as UHR-SIG. 【0073】 The name "UHR-SIG field" is a convenient designation used to identify it as a SIG field compliant with the IEEE 802.11bn standard. Therefore, another name may be used instead of "UHR-SIG field." 【0074】 Furthermore, a SIG field corresponding to or related to a specified standard may consist of multiple SIG fields. For example, a SIG field corresponding to or related to a specified standard may consist of two SIG fields, such as UHR-SIG-A field and UHR-SIG-B field, or it may consist of three or more SIG fields. 【0075】 Furthermore, although this embodiment describes an ELR PPDU compliant with the UHR standard as an example, if the PPDU complies with a predetermined standard other than UHR, the name UHR-SIG may be replaced with another name. 【0076】 Furthermore, subsequent UHR-SIG fields can have multiple repeating structures, and the U-SIG2 field includes a Number of UHR-SIG Repetition field that specifies the number of UHR-SIG fields. The value stored in the Number of UHR-SIG Repetition field may be the number of UHR-SIG fields, or it may be the number of UHR-SIG fields minus a certain value. For example, the number obtained by subtracting 1 from the number of UHR-SIG fields may be stored in the Number of UHR-SIG Repetition field. 【0077】 The UHR-SIG MCS field specifies the MCS for the subsequent UHR-SIG field. An example of the details of the UHR-SIG field's MCS is shown in Figure 7. 【0078】 Figure 7 shows an example of the relationship between the value (index value) of the UHR-SIG MCS field and the communication parameters according to this embodiment. 【0079】 In the example shown in Figure 7, the communication parameters include modulation scheme, coding rate (R), number of coded bits per subcarrier per spatial stream (NBPSCS), and number of subcarriers (NSD). In the example shown in Figure 7, the communication parameters also include number of coded bits per symbol (NCBPS), number of data bits per symbol (NDBPS), and UHR-SIG rate. 【0080】 In this embodiment, the UHR-SIG MCS field is set to 2 bits, but the number of bits may be other values. Furthermore, the MCS of the UHR-SIG field may be fixed to, for example, BPSK (Binary Phase-Shift Keying) and not specified in the U-SIG field. Also, in the case of an ELR PPDU, the value of the UHR-SIG MCS field may be a fixed value (for example, the value "0" shown in Figure 7). That is, in the case of an ELR PPDU, the MCS of the UHR-SIG field is fixed, but the UHR-SIG MCS field may indicate that MCS. 【0081】 Other fields conform to the U-SIG field format defined in the IEEE 802.11be standard, however, the fields included in the U-SIG field do not necessarily have to be those shown in Table 1. 【0082】 [Table 1] 【0083】 The modulation scheme for U-SIG field 605 is BPSK (Binary Phase-Shift Keying). The modulation scheme for U-SIG field 606 is also BPSK, but it is QBPSK (Quadrature BPSK), where the phase of the modulated signal is 90 degrees different from that of U-SIG field 605. A communication device that receives this frame (ELR PPDU) can determine that the received frame (PPDU) is an ELR PPDU from the following (1) and (2): (1) U-SIG field 605 and U-SIG field 606 are consecutive. (2) The phases of the modulated signals are different (they are modulated using different modulation schemes). Other methods can also be considered for determining that the received PPDU is an ELR PPDU. For example, such a method may include the following (a) and (b): (a) Determining whether the remainder when the value of the Length field in RL-SIG field 604 is divided by 3 is a predetermined value. (b) Determine the difference in modulation scheme between U-SIG field 605 and U-SIG field 606 (for example, if the remainder is a predetermined value). The predetermined value is, for example, 2. By making the modulation scheme of U-SIG field 605 and U-SIG field 606 different, it becomes possible to perform long-distance communication without discrepancies in recognition between communication devices. 【0084】 In this embodiment, the modulation scheme for U-SIG field 605 and U-SIG field 606 are set to BPSK and QBPSK, respectively. However, this disclosure is not limited thereto, and different modulation schemes may be used for U-SIG field 605 and U-SIG field 606. 【0085】 Returning to the explanation of Figure 6(a), following U-SIG fields 605 and 606, there is a UHR-SIG field 607 for transmitting control information for UHR. Multiple UHR-SIG fields can exist. The number of UHR-SIG fields can be specified by the Number of UHR-SIG Repetition field included in U-SIG fields 605 and 606, as described above. In this embodiment, the value of the Number of UHR-SIG Repetition field is 2, meaning there are two UHR-SIG fields. Following UHR-SIG field 607, there is a UHR-SIG field 608, which consists of the same data as UHR-SIG field 607. 【0086】 As mentioned above, the number of UHR-SIG fields can be specified in the U-SIG field, but it may also be a fixed number. Alternatively, the number of UHR-SIG fields may be the same as the number of U-SIG fields. In this case, the number of UHR-SIG fields may be variable, and the number of UHR-SIG fields may be indicated by (for example, new) fields or elements in other fields preceding the UHR-SIG fields. 【0087】 Table 2 below shows examples of elements that make up a UHR-SIG field. A UHR-SIG field is a field that may contain information about the repetition of a given subsequent field. A UHR-SIG field includes a GI+LTF Size field that specifies the length of the Guard Interval (GI) and the number of subsequent UHR-LTF fields. The GI+LTF Size field indicates the number of LTFs and the pattern of GI, for example, as follows: If the value of the GI+LTF Size field is 0, the number of LTFs is 2 and GI = 0.8 microseconds. If the value of the GI+LTF Size field is 1, the number of LTFs is 2 and GI = 1.6 microseconds. If the value of the GI+LTF Size field is 2, the number of LTFs is 4 and GI = 0.8 microseconds. If the value of the GI+LTF Size field is 3, the number of LTFs is 4 and GI = 3.2 microseconds. However, the number of LTF fields and the GI length value do not have to be the values ​​described above, and the GI+LTF Size field may be other than 2 bits. Also, the GI+LTF Size field may be included in the U-SIG field. 【0088】 [Table 2] 【0089】 The ELR PPDU shown in Figure 6(a) further includes an STF for UHR (UHR-STF609) and an LTF for UHR (UHR-LTF610, ..., UHR-LTF611). In the case of the ELR PPDU, a power boost of, for example, 3dB may be applied to the UHR-STF609 and UHR-LTF610 (, ..., UHR-LTF611) compared to other types of PPDUs. Note that the amount of power boost is not limited to 3dB. As a result, the UHR-STF609 and UHR-LTF610 (, ..., UHR-LTF611) following UHR-SIG607 and 608 will have a stronger transmission strength compared to other fields. It is expected that the power boost will improve the SNR of the field and increase the transmittable distance of the ELR PPDU between the transmitting terminal and the receiving terminal. 【0090】 The ELR PPDU includes data fields and a Packet extension field (not shown) following these control fields. The fields from L-STF to UHR-LTF included in the ELR PPDU are called the PHY preamble. 【0091】 The name "UHR-SIG field" is a convenient designation used to identify it as a SIG field compliant with the IEEE 802.11bn standard. Therefore, another name may be used instead of "UHR-SIG field." 【0092】 Furthermore, a SIG field corresponding to or related to a specified standard may consist of multiple SIG fields. For example, a SIG field corresponding to or related to a specified standard may consist of two SIG fields, such as UHR-SIG-A field and UHR-SIG-B field, or it may consist of three or more SIG fields. 【0093】 Furthermore, in this embodiment, an ELR PPDU compliant with the UHR standard is described as an example, but if the PPDU complies with a predetermined standard other than UHR, the name UHR-SIG may be replaced with another name. Also, UHR-SIG may be replaced with ELR-SIG. In addition, UHR-STF and UHR-LTF may be replaced with other names such as ELR-STF and ELR-LTF, respectively. 【0094】 Another form of ELR PPDU is the format shown in Figure 6(b). This format will be explained below. 【0095】 The L-STF601 to RL-SIG fields 604 in the ELR PPDU format shown in Figure 6(b) are identical to the L-STF601 to RL-SIG fields 604 shown in Figure 6(a), so their explanation is omitted. 【0096】 The ELR PPDU shown in Figure 6(b) includes U-SIG field 612, which contains information common to IEEE 802.11be and later standards, and UHR-SIG field 613, which are placed immediately after RL-SIG604. Following UHR-SIG field 613 are U-SIG field 614 and UHR-SIG field 615, in that order. 【0097】 U-SIG field 612 and UHR-SIG field 613 are modulated using the BPSK method, and U-SIG field 614 and UHR-SIG field 615 are modulated using the QBPSK method. A communication device that receives this frame (ELR PPDU) can determine that the received frame (PPDU) is an ELR PPDU from the following (1) and (2): (1) U-SIG field 614 and UHR-SIG field 615 follow U-SIG field 612 and UHR-SIG field 613. (2) The modulation methods are different, one being BPSK and the other QBPSK. Other methods can also be considered for determining that the received PPDU is an ELR PPDU. For example, such a method may include the following (a) and (b): (a) Determining whether the remainder when the value of the Length field in RL-SIG field 604 is divided by 3 is a predetermined value. (b) Determine the difference in modulation scheme between U-SIG field 612 and UHR-SIG field 613 and U-SIG field 614 and UHR-SIG field 615 (for example, if the remainder is a predetermined value). The predetermined value is, for example, 2. By making the modulation schemes of U-SIG field 612 and UHR-SIG field 613 different from those of U-SIG field 614 and UHR-SIG field 615, it becomes possible to perform long-distance communication without discrepancies in recognition between communication devices. 【0098】 In this embodiment, the modulation schemes for U-SIG field 612 and UHR-SIG field 613 and U-SIG field 614 and UHR-SIG field 615 are set to BPSK and QBPSK, respectively. However, this disclosure is not limited thereto, and different modulation schemes may be used for U-SIG field 612 and UHR-SIG field 613 and U-SIG field 614 and UHR-SIG field 615. 【0099】 A UHR-SIG field 616 may be present following the UHR-SIG field 615. The modulation scheme of the UHR-SIG field following the UHR-SIG field 615 may be either BPSK or QBPSK. 【0100】 The configuration of the U-SIG fields (U-SIG fields 612 and 614, respectively) may be the same as the configuration shown in Table 1 above. The U-SIG field consists of the U-SIG1 field and the U-SIG2 field. 【0101】 The U-SIG2 field includes the UHR-SIG MCS field, which indicates the MCS used for modulation of the subsequent UHR-SIG field. 【0102】 The UHR-SIG MCS field specifies the MCS of the subsequent UHR-SIG field. The details of the MCS of the UHR-SIG field may be the same as those shown in Figure 7. Furthermore, the MCS of UHR-SIG fields 613, 615, and 616 may be fixed to, for example, BSPK and not specified in the U-SIG field. Also, in the case of ELR PPDU, the value of the UHR-SIG MCS field may be a fixed value. That is, in the case of ELR PPDU, the MCS of UHR-SIG fields 613, 615, and 616 are fixed, but the UHR-SIG MCS field may indicate that MCS. 【0103】 The number of UHR-SIG fields can be specified by the Number of UHR-SIG Repetition field contained in U-SIG fields 612 and 614. In this embodiment, since UHR-SIG fields 613, 615, and 616 exist, the value of the Number of UHR-SIG Repetition field is 3. 【0104】 The value stored in the Number of UHR-SIG Repetition field may be the number of UHR-SIG fields, or it may be the number of UHR-SIG fields minus a certain value. For example, if the ELR PPDU always includes UHR-SIG fields 613, 615, and 616, then the value stored in the Number of UHR-SIG Repetition field may be the number of UHR-SIG fields minus 2. In this embodiment, 1, which is 3 minus 2, is the value indicated in the Number of UHR-SIG Repetition field. 【0105】 As mentioned above, the number of UHR-SIG fields can be specified in the U-SIG field, but it may also be a fixed number. Alternatively, the number of UHR-SIG fields may be the same as the number of U-SIG fields. In this case, the number of UHR-SIG fields may be variable, and the number of UHR-SIG fields may be indicated by (for example, new) fields or elements in other fields preceding the UHR-SIG fields. 【0106】 The UHR-SIG field includes the GI+LTF Size field, which specifies the length of the GI and the number of subsequent UHR-LTF fields. 【0107】 The ELR PPDU shown in Figure 6(b) includes an STF (UHR-STF617) and an LTF (UHR-LTF618, ...) for UHR. The number of UHR-LTFs is specified by the GI+LTF Size field. In the case of the ELR PPDU, a power boost of, for example, 3dB may be applied to the UHR-STF617 and UHR-LTF618 (...) compared to other types of PPDUs. The amount of power boost is not limited to 3dB. As a result, the UHR-STF617 and UHR-LTF618 (...) following the UHR-SIG fields 613, 615, and 616 will have a stronger transmission strength compared to other fields. The power boost is expected to improve the SNR of these fields and increase the transmittable distance of the ELR PPDU between the transmitting and receiving terminals. 【0108】 The ELR PPDU includes data fields and a Packet extension field (not shown) following these control fields. The fields from L-STF to UHR-LTF included in the ELR PPDU are called the PHY preamble. 【0109】 Note that the arrangement of fields constituting the PHY preamble is not limited to the examples shown in Figures 6(a) and 6(b), and these fields may be arranged in a different order. Also, the preamble does not have to include all the fields shown in Figures 6(a) and 6(b), and may include only some of the fields. Furthermore, other fields different from those shown in Figures 6(a) and 6(b) may be added to the preamble. Note that arranging the fields constituting the PHY preamble as shown in the examples in Figures 6(a) and 6(b) may improve communication efficiency. In addition, the fields of the PHY preamble excluding legacy fields may be collectively called the ELR preamble. 【0110】 In this embodiment, Figures 5(a) and 5(b) show a PPDU that ensures backward compatibility as an example. However, if backward compatibility is not required, the legacy fields may be omitted, for example. In this case, for example, UHR-STF or UHR-LTF may be used instead of L-STF and L-LTF to establish synchronization. In this case, the UHR-STF after UHR-SIG or one of the multiple UHR-LTFs may be omitted. 【0111】 As described above, according to this embodiment, by using the exemplary ELR PPDU shown in Figure 6(a) or Figure 6(b), it becomes possible to properly perform communication using the ELR PPDU without any discrepancies in recognition between communication devices. In other words, the communication device can perform long-distance communication using the exemplary ELR PPDU shown in Figure 6(a) or Figure 6(b) according to the processing example shown in Figure 4. 【0112】 Alternatively, a storage medium containing program code for software that implements the above-described functions may be supplied to a system or device, and the computer (CPU, MPU) of the system or device may read and execute the program code stored on the storage medium. In this case, the program code read from the storage medium itself will implement the functions of the above-described embodiment, and the storage medium containing that program code will constitute the above-described device. 【0113】 For supplying program code, storage media such as flexible disks, hard disks, optical disks, magneto-optical disks, CD-ROMs, CD-Rs, magnetic tapes, non-volatile memory cards, ROMs, DVDs, etc., can be used. 【0114】 Furthermore, the above-mentioned functions may be realized not only by the computer executing the program code it reads, but also by the operating system running on the computer performing some or all of the actual processing based on the instructions of that program code. 【0115】 Furthermore, the program code read from the storage medium is written to the memory of a function expansion board inserted into the computer or a function expansion unit connected to the computer. Then, based on the instructions of that program code, the CPU of the function expansion board or function expansion unit may perform some or all of the actual processing to realize the above-mentioned functions. 【0116】 This disclosure can also be implemented by supplying a program that implements one or more of the functions of the embodiments described above to a system or device via a network or storage medium, and by having one or more processors in the computer of that system or device read and execute the program. Furthermore, this disclosure can also be implemented by a circuit (e.g., an ASIC) that implements one or more functions. 【0117】 Furthermore, some of the processes described in this disclosure with reference to the flowchart may be implemented in hardware. For example, a dedicated circuit can be automatically generated on the FPGA from a program to implement each step by using a predetermined compiler. Alternatively, a Gate Array circuit may be formed in the same way as the FPGA and implemented in hardware. 【0118】 The names of the functional units, messages, parameters, fields, etc., described in the embodiments described above may be changed to other names. 【0119】 The order of the processing procedures, sequences, flowcharts, etc., in the embodiments described above is not limited to the specific order presented, and may be rearranged or additional steps may be added, as long as they do not contradict each other. 【0120】 Furthermore, the following additional information is disclosed regarding the above embodiments. 【0121】 [Note 1] A communication device compliant with the IEEE 802.11 standard series, The system includes a transmission means for transmitting a PPDU (Physical Layer Protocol Data Unit) having a preamble that includes a first U-SIG (Universal Signal) field, a second U-SIG field containing the same data as the first U-SIG field, a first UHR-SIG (Ultra High Reliability Signal) field, and a second UHR-SIG field containing the same data as the first UHR-SIG field. A communication device in which the first U-SIG field and the second U-SIG field are modulated using different modulation schemes. 【0122】 [Note 2] The communication device described in Appendix 1, wherein the first UHR-SIG field and the second UHR-SIG field are modulated using different modulation schemes. 【0123】 [Note 3] The communication device according to Appendix 1 or 2, wherein the first U-SIG field and the second U-SIG field include information relating to a predetermined field repetition following the second U-SIG field. 【0124】 [Note 4] The communication device according to any one of the appendices 1 to 3, wherein the first UHR-SIG field and the second UHR-SIG field include information relating to the repetition of a predetermined field following the second U-SIG field. 【0125】 [Note 5] The communication device according to any one of the appendices 1 to 4, wherein the first U-SIG field and the second U-SIG field include values ​​indicating the modulation scheme of the first UHR-SIG field and the second UHR-SIG field. 【0126】 [Note 6] A communication device according to any one of the appendices 1 to 5, wherein all or part of the field following the second UHR-SIG field has a stronger transmission strength compared to other fields. 【0127】 [Note 7] A communication device compliant with the IEEE 802.11 standard series, The system has receiving means for receiving a PPDU (Physical Layer Protocol Data Unit) having a preamble that includes a first U-SIG (Universal Signal) field, a second U-SIG field containing the same data as the first U-SIG field, a first UHR-SIG (Ultra High Reliability Signal) field, and a second UHR-SIG field containing the same data as the first UHR-SIG field. A communication device in which the first U-SIG field and the second U-SIG field are modulated using different modulation schemes. 【0128】 [Note 8] The communication device described in Appendix 7, wherein the first UHR-SIG field and the second UHR-SIG field are modulated using different modulation schemes. 【0129】 [Note 9] The communication device according to Appendix 7 or 8, wherein the first U-SIG field and the second U-SIG field include information relating to a predetermined field repetition following the second U-SIG field. 【0130】 [Note 10] The communication device according to any one of the appendices 7 to 9, wherein the first UHR-SIG field and the second UHR-SIG field include information relating to a predetermined field repetition following the second UHR-SIG field. 【0131】 [Note 11] The communication device according to any one of the appendices 7 to 10, wherein the first U-SIG field and the second U-SIG field include values ​​indicating the modulation scheme of the first UHR-SIG field and the second UHR-SIG field. 【0132】 [Note 12] The communication device according to Appendix 1 or 7, further comprising a notification means for notifying PPDU transmission / reception availability information indicating whether or not the communication device is in a state where PPDU transmission / reception is possible. 【0133】 [Note 13] The notification means is a communication device as described in Appendix 12, which uses a management frame to notify the PPDU transmission / reception feasibility information. 【0134】 [Note 14] The communication device as described in Appendix 13, wherein the management frame is a beacon frame, association request frame, association response frame, reassociation request frame, reassociation response frame, probe request frame, or probe response frame. 【0135】 [Note 15] The notification means is a communication device according to any one of appendices 12 to 14, which notifies the PPDU transmission / reception capability information using a data frame. 【0136】 [Note 16] The aforementioned data frame is a QoS Data frame or a QoS Null frame, as described in Appendix 15 of the communication device. 【0137】 [Note 17] The QoS Data frame or the QoS Null frame includes the PPDU transmission / reception capability information in the A-Control field, as described in Appendix 16, for the communication device. 【0138】 [Note 18] The notification means is a communication device according to any one of the appendices 12 to 17, which notifies the PPDU transmission / reception capability information for each of the multiple bands on which the communication device can communicate, in all or some of the bands. 【0139】 [Note 19] The notification means is a communication device according to any one of appendices 12 to 17, which notifies the PPDU transmission / reception availability information in the band in which the PPDU transmission / reception availability information is notified. 【0140】 [Note 20] The device further includes a means for changing the PPDU transmission / reception availability information according to the level of communication congestion of the BSS (Basic Service Set) to which the communication device belongs. The notification means is a communication device according to any one of the appendices 12 to 19 that notifies the changed PPDU transmission / reception availability information. 【0141】 [Note 21] The system further includes a setting means for setting the PPDU transmission / reception availability information to unavailable if other communication methods for extending the communication distance are available. The notification means is a communication device according to any one of the appendices 12 to 20 that notifies the set PPDU transmission / reception capability information. 【0142】 [Note 22] The PPDU transmission / reception capability information is included in an element containing capability information, and is a communication device as described in any of appendices 12 to 21. 【0143】 [Note 23] A control method for communication equipment compliant with the IEEE 802.11 standard series, The process includes transmitting a PPDU (Physical Layer Protocol Data Unit) having a preamble that includes a first U-SIG (Universal Signal) field, a second U-SIG field containing the same data as the first U-SIG field, a first UHR-SIG (Ultra High Reliability Signal) field, and a second UHR-SIG field containing the same data as the first UHR-SIG field. A control method in which the first U-SIG field and the second U-SIG field are modulated using different modulation schemes. 【0144】 [Note 24] A control method for communication equipment compliant with the IEEE 802.11 standard series, The process includes receiving a PPDU (Physical Layer Protocol Data Unit) having a preamble that includes a first U-SIG (Universal Signal) field, a second U-SIG field containing the same data as the first U-SIG field, a first UHR-SIG (Ultra High Reliability Signal) field, and a second UHR-SIG field containing the same data as the first UHR-SIG field. A control method in which the first U-SIG field and the second U-SIG field are modulated using different modulation schemes. 【0145】 [Note 25] A program for causing a computer to perform the control method described in Appendix 23 or 24. [Explanation of symbols] 【0146】 102 AP 103, 104, 105 STA

Claims

[Claim 1] A communication device compliant with the IEEE 802.11 standard series, The system includes a transmission means for transmitting a PPDU (Physical Layer Protocol Data Unit) having a preamble that includes a first U-SIG (Universal Signal) field, a second U-SIG field containing the same data as the first U-SIG field, a first UHR-SIG (Ultra High Reliability Signal) field, and a second UHR-SIG field containing the same data as the first UHR-SIG field. A communication device in which the first U-SIG field and the second U-SIG field are modulated using different modulation schemes. [Claim 2] The communication device according to claim 1, wherein the first UHR-SIG field and the second UHR-SIG field are modulated using different modulation schemes. [Claim 3] The communication device according to claim 1, wherein the first U-SIG field and the second U-SIG field include information relating to a predetermined field repetition following the second U-SIG field. [Claim 4] The communication device according to claim 1, wherein the first UHR-SIG field and the second UHR-SIG field include information relating to a predetermined field repetition following the second UHR-SIG field. [Claim 5] The communication device according to claim 1, wherein the first U-SIG field and the second U-SIG field include values ​​indicating the modulation scheme of the first UHR-SIG field and the second UHR-SIG field. [Claim 6] The communication device according to claim 1, wherein all or part of the field following the second UHR-SIG field has a stronger transmission strength compared to the other fields. [Claim 7] A communication device compliant with the IEEE 802.11 standard series, The system has receiving means for receiving a PPDU (Physical Layer Protocol Data Unit) having a preamble that includes a first U-SIG (Universal Signal) field, a second U-SIG field containing the same data as the first U-SIG field, a first UHR-SIG (Ultra High Reliability Signal) field, and a second UHR-SIG field containing the same data as the first UHR-SIG field. A communication device in which the first U-SIG field and the second U-SIG field are modulated using different modulation schemes. [Claim 8] The communication device according to claim 7, wherein the first UHR-SIG field and the second UHR-SIG field are modulated using different modulation schemes. [Claim 9] The communication device according to claim 7, wherein the first U-SIG field and the second U-SIG field include information relating to a predetermined field repetition following the second U-SIG field. [Claim 10] The communication device according to claim 7, wherein the first UHR-SIG field and the second UHR-SIG field include information relating to a predetermined field repetition following the second UHR-SIG field. [Claim 11] The communication device according to claim 7, wherein the first U-SIG field and the second U-SIG field include values ​​indicating the modulation scheme of the first UHR-SIG field and the second UHR-SIG field. [Claim 12] The communication device according to claim 1 or 7, further comprising notification means for notifying PPDU transmission / reception capability information indicating whether or not the communication device is in a state where PPDU transmission / reception is possible. [Claim 13] The communication device according to claim 12, wherein the notification means notifies the PPDU transmission / reception capability information using a management frame. [Claim 14] The communication device according to claim 13, wherein the management frame is a beacon frame, an Association request frame, an Association response frame, a Response request frame, a Response frame, a Probe request frame, or a Probe response frame. [Claim 15] The communication device according to claim 12, wherein the notification means notifies the PPDU transmission / reception capability information using a data frame. [Claim 16] The communication device according to claim 15, wherein the data frame is a QoS Data frame or a QoS Null frame. [Claim 17] The communication device according to claim 16, wherein the QoS Data frame or the QoS Null frame includes the PPDU transmission / reception capability information in the A-Control field. [Claim 18] The communication device according to claim 12, wherein the notification means notifies the PPDU transmission / reception capability information for each of all or some of the multiple bands on which the communication device can communicate. [Claim 19] The communication device according to claim 12, wherein the notification means notifies the PPDU transmission / reception availability information in the band in which the PPDU transmission / reception availability information is notified. [Claim 20] The device further includes a means for changing the PPDU transmission / reception availability information according to the level of communication congestion of the BSS (Basic Service Set) to which the communication device belongs. The communication device according to claim 12, wherein the notification means notifies the changed PPDU transmission / reception capability information. [Claim 21] If other communication methods for extending the communication distance are available, the system further includes setting means to set the PPDU transmission / reception availability information to unavailable. The communication device according to claim 12, wherein the notification means notifies the set PPDU transmission / reception capability information. [Claim 22] The communication device according to claim 12, wherein the PPDU transmission / reception capability information is included in an element that includes capability information. [Claim 23] A control method for communication equipment compliant with the IEEE 802.11 standard series, The process includes transmitting a PPDU (Physical Layer Protocol Data Unit) having a preamble that includes a first U-SIG (Universal Signal) field, a second U-SIG field containing the same data as the first U-SIG field, a first UHR-SIG (Ultra High Reliability Signal) field, and a second UHR-SIG field containing the same data as the first UHR-SIG field. A control method in which the first U-SIG field and the second U-SIG field are modulated using different modulation schemes. [Claim 24] A control method for communication equipment compliant with the IEEE 802.11 standard series, The process includes receiving a PPDU (Physical Layer Protocol Data Unit) having a preamble that includes a first U-SIG (Universal Signal) field, a second U-SIG field containing the same data as the first U-SIG field, a first UHR-SIG (Ultra High Reliability Signal) field, and a second UHR-SIG field containing the same data as the first UHR-SIG field. A control method in which the first U-SIG field and the second U-SIG field are modulated using different modulation schemes. [Claim 25] A program for causing a computer to execute the control method described in claim 23 or 24.

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