Communication apparatus, communication method, and storage medium

Abstract

The invention provides a communication device, a communication method and a storage medium. The communication apparatus includes a notification section for notifying one or more other communication apparatuses different from the communication apparatus of a total number of spatial streams formed by two or more communication apparatuses among the communication apparatus and the one or more other communication apparatuses, the communication module is used for communicating with a public partner device.

Description

[0001] This application is a divisional application of an invention patent application with an application date of February 5, 2020, application number 202080017284.9 (international application number PCT / JP2020 / 004256), and invention name “Communication equipment, communication method and storage medium”. Technical Field

[0002] The present invention relates to a communication control technology in a wireless LAN. Background Art

[0003] Recently, with the development of information communication technology, the use of the Internet has increased year by year, and various communication technologies have been developed to cope with the increase in demand. In particular, wireless local area network (wireless LAN) technology has achieved improved throughput in Internet communications for packet data, audio, video, etc. through wireless LAN terminals, and various technical developments are still being actively carried out.

[0004] In the development of wireless LAN technology, many standardization works of IEEE (Institute of Electrical and Electronics Engineers) 802, which is a standardization organization for wireless LAN technology, have played an important role. As one of the wireless LAN communication standards, the IEEE 802.11 standard is known, including standards such as IEEE 802.11n / a / b / g / ac and IEEE 802.11ax. For example, IEEE 802.11ax achieves a high peak throughput of up to 9.6 gigabits per second (Gbps) using OFDMA (Orthogonal Frequency Division Multiple Access), and also improves the communication speed under congested conditions (PTL 1).

[0005] Recently, in order to further improve the throughput, a research group called IEEE802.11EHT (Extremely High Throughput) has been formed as a successor standard to IEEE802.11ax. In order to achieve the throughput improvement that is the goal of IEEE802.11EHT, D-MIMO (Distributed MIMO) has been examined, which is constructed to increase the number of antennas by enabling multiple spatially distributed access points to operate cooperatively. Note that MIMO is an abbreviation for Multi-Input Multi-Output. Traditionally, during communication between an access point and a STA (station) as a wireless LAN terminal, even if multiple access points can be connected to the STA, access points other than the access points that have been connected to the STA will not communicate with the STA to avoid communication conflicts. D-MIMO is a technology that enables multiple access points to communicate with the STA via the same channel at the same time using multiple spatial streams formed by multiple antennas, and D-MIMO can achieve throughput improvement by improving spatial utilization efficiency.

[0006] Reference List

[0007] Patent Literature

[0008] PTL 1: Japanese Patent Application Publication No. 2018-50133 Summary of the invention

[0009] Technical issues

[0010] When a STA communicates with multiple access points applicable to D-MIMO, the STA preferably has information about spatial streams formed by all access points when performing communication processing. However, in the conventional standard, there is no limitation on setting the number of spatial streams formed by multiple access points in a frame to be transmitted to the STA.

[0011] In view of the above-mentioned problems, the present disclosure provides a technology for causing a wireless LAN terminal to obtain information on the number of spatial streams formed by a plurality of access points.

[0012] Technical solutions to the problem

[0013] A communication device according to one aspect of the present invention has the following characteristics. That is, a communication device is provided, which includes a transmitting unit, the transmitting unit is used to send a physical (PHY) frame including a preamble and a data field, characterized in that the preamble includes:

[0014] Legacy Short Training Field (L-STF);

[0015] a legacy long training field (L-LTF) arranged immediately after the L-STF in the frame;

[0016] a legacy signal field (L-SIG) disposed immediately after the L-LTF in the frame;

[0017] an EHT (Extreme High Throughput) signal field (EHT-SIG-A) arranged after the L-SIG in the frame;

[0018] an ETH Short Training Field (EHT-STF) arranged immediately after the EHT-SIG-A in the frame; and

[0019] an EHT long training field (EHT-LTF) arranged immediately after the EHT-STF in the frame, and

[0020] The EHT-SIG-A includes a subfield indicating the number of spatial streams formed by the communication device and at least one communication device other than the communication device and used to transmit the frame.

[0021] Advantageous Effects of the Invention

[0022] According to the present invention, it is possible to enable a wireless LAN terminal to obtain information on the number of spatial streams formed by a plurality of access points.

[0023] Other features and advantages of the present invention will become more apparent from the following description in conjunction with the accompanying drawings. Note that throughout the accompanying drawings, the same reference numerals designate the same or similar components. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate embodiments of the present invention and, together with the description, serve to explain the principles of the present invention.

[0025] Figure 1 is a diagram showing an example of the configuration of a network;

[0026] Figure 2 is a block diagram showing an example of a functional configuration of an AP;

[0027] Figure 3 is a block diagram showing an example of a hardware configuration of an AP;

[0028] Figure 4 is a flow chart showing a process performed by an AP;

[0029] Figure 5 is a sequence diagram illustrating a process performed in a wireless communication network;

[0030] Figure 6 is a diagram showing an example of a PHY frame structure of an ETH SU PPDU;

[0031] Figure 7 is a diagram showing an example of a PHY frame structure of an ETH ER PPDU; and

[0032] Figure 8 is a diagram showing an example of a PHY frame structure of an ETH MU PPDU. DETAILED DESCRIPTION

[0033] Embodiments will be described in detail below with reference to the accompanying drawings. Note that the following embodiments are not intended to limit the scope of the present invention. A plurality of features are described in the embodiments, but the invention is not limited to requiring all of these features, but a plurality of such features may be appropriately combined. In addition, in the accompanying drawings, the same reference numerals are given to the same or similar structures, and their redundant descriptions will be omitted.

[0034] (Network Structure)

[0035] Figure 11 shows an example of the construction of a wireless communication network according to this embodiment. The wireless communication network is constructed to include three access points (AP102, AP103, and AP104) and three STAs (STA105, STA106, and STA107) that are devices (EHT devices) that comply with the IEEE802.11 EHT (Extremely High Throughput) standard. Note that it can be understood that EHT is an acronym for Extremely High Throughput. Figure 1 As shown, a network formed by AP 102, AP 103, and AP 104 in cooperation is indicated by circle 101. In the present embodiment, AP 103 and AP 104 can send / receive signals sent / received by AP 102. Note that AP 102 and AP 103 or AP 102 and AP 104 can be connected by wire or wirelessly. In addition, AP 103 and AP 104 may or may not be able to send / receive signals to each other. In the present embodiment, STA 105 can send / receive frames from AP 103 and AP 104. Here, AP 103 and AP 104 that directly send / receive signals to / from each STA will be referred to as slave access points (S-APs). In addition, AP 102 that can send / receive frames to / from each STA by issuing instructions to AP 103 and AP 104 will be referred to as a master access point (hereinafter referred to as M-AP). Note that the AP 102 as an M-AP can directly transmit / receive signals to / from the STA 105. In this case, the AP 102 can operate as both an M-AP and an S-AP.

[0036] APs 102 to 104 are applicable to D-MIMO (distributed MIMO), which is one of the methods for forming a multi-AP coordination system in the IEEE802.11EHT standard. In the present embodiment, AP 103 and AP 104 maintain two antennas and four antennas, respectively. Therefore, the maximum number of spatial streams (hereinafter referred to as the number of streams) applicable to AP 103 is 2, and the maximum number of streams applicable to AP 104 is 4. In addition, the maximum number of streams applicable to AP 102 is 1, and the maximum number of streams applicable to STA 105 is 8. Note that these numbers are only examples for description, and other numbers of antennas (number of streams) may be used.

[0037] Note that if APs are in the same wireless communication network, each AP can play the role of M-AP. Figure 1 In the example, AP 103 or AP 104 may also be an M-AP. The M-AP may play a role of sending instructions to each AP without sending a beacon, for example.

[0038] Notice, Figure 1 The configuration of the wireless communication network shown is only an example for description, and for example, a network including many EHT devices and conventional devices (communication devices conforming to the IEEE802.11a / b / g / n / ax standards) in a wider area may be formed. In addition, the arrangement of the communication devices is not limited to Figure 1 The arrangement shown, and the following arguments also apply to various positional relationships of the communication devices.

[0039] (AP Structure)

[0040] Figure 2 1 is a block diagram showing a functional configuration of the AP 103. Note that the AP 104 has the same functional configuration as the AP 103. The AP 103 includes a wireless LAN control unit 201, a frame generation unit 202, a signal analysis unit 203, and a UI (User Interface) control unit 204 as an example of its functional configuration.

[0041] The wireless LAN control unit 201 may be configured to include: one or more antennas 205 and circuits configured to send / receive radio signals (radio frames) to / from other wireless LAN devices, and a program configured to control these. The wireless LAN control unit 201 performs communication control of the wireless LAN based on the frame generated by the frame generation unit 202 according to the IEEE802.11 series of standards.

[0042] The frame generation unit 202 generates a frame to be transmitted by the wireless LAN control unit 201 based on the result of the analysis of the signal received by the wireless LAN control unit 201 by the signal analysis unit 203. The frame generation unit 202 can create a frame without relying on the analysis result of the signal analysis unit 203. The signal analysis unit 203 analyzes the signal received by the wireless LAN control unit 201. For example, if the AP 103 performs a D-MIMO operation and operates as an S-AP, the signal analysis unit 203 analyzes the content of the received frame. At this time, regarding the frame transmitted by the AP 103 to the STA 105, the signal analysis unit 203 can obtain information indicating how many APs other than the AP 103 that transmit frames to the STA 105 exist, and how many antennas exist, through analysis. The UI control unit 204 accepts a user (not shown) of the AP 102 in response to the input unit 304 ( Figure 3 ) operation, and controls the control signal corresponding to the operation to be sent to each component, or controls the output unit 305 ( Figure 3 ) output (including display, etc.).

[0043] Figure 31 shows a hardware configuration of the AP 103 according to this embodiment. Note that the AP 104 has the same hardware configuration as the AP 103. As an example of its hardware configuration, the AP 103 includes 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 one or more antennas 205.

[0044] The storage unit 301 is composed of both or one of a ROM and a RAM, and stores programs for performing various operations described later and various information such as communication parameters for wireless communication. Note that in addition to memories such as ROM and RAM, a storage medium such as a floppy disk, a hard disk, an optical disk, a magneto-optical disk, a CD-ROM, a CD-R, a magnetic tape, a nonvolatile memory card, or a DVD can be used as the storage unit 301.

[0045] The control unit 302 is composed of, for example, a processor such as a CPU or an MPU, an ASIC (Application Specific Integrated Circuit), a DSP (Digital Signal Processor), an FPGA (Field Programmable Gate Array), etc. Here, CPU is an acronym for a Central Processing Unit, and MPU is an acronym for a Micro Processing Unit. The control unit 302 executes a program stored in the storage unit 301, thereby controlling the entire AP 103. Note that the control unit 302 can control the entire AP 103 through the cooperation of the program stored in the storage unit 301 and the OS (Operating System).

[0046] In addition, the control unit 302 controls the function unit 303 to perform a predetermined process such as video recording, printing, or projection. The function unit 303 is hardware used by the AP 103 to perform a predetermined process. For example, if the AP 103 is a camera, the function unit 303 is a video recording unit and performs video recording processing. For example, if the AP 103 is a printer, the function unit 303 is a printing unit and performs printing processing. For example, if the AP 103 is a projector, the function unit 303 is a projection unit and performs projection processing. The data to be processed by the function unit 303 may be data stored in the storage unit 301, or may be data communicated with the STA or other APs via the communication unit 306 described later.

[0047] The input unit 304 accepts various operations from the user. The output unit 305 performs various outputs for the user. Here, the output of the output unit 305 includes at least one of display on the screen, audio output of the speaker, vibration output, etc. Note that both the input unit 304 and the output unit 305 can be implemented by a module like a touch panel.

[0048] The communication unit 306 controls wireless communication conforming to the IEEE802.11EHT standard, or IP (Internet Protocol) communication. In addition, the communication unit 306 controls one or more antennas 205 to send / receive radio signals for wireless communication. The AP 103 communicates contents such as image data, document data, and video data with other communication devices via the communication unit 306. Note that in the present embodiment, as described above, the AP 103 and the AP 104 have two antennas and four antennas, respectively.

[0049] (STA structure)

[0050] The functional configuration and hardware configuration of the STA 105 are respectively the same as the functional configuration of the AP 103 described above ( Figure 2 ) and hardware configuration ( Figure 3 That is, the STA 105 may be configured to include the wireless LAN control unit 201, the frame generation unit 202, the signal analysis unit 203, and the UI control unit 204 as its functional configuration, and to include the storage unit 301, the control unit 302, the functional unit 303, the input unit 304, the output unit 305, the communication unit 306, and the antenna 205 as its hardware configuration.

[0051] (Processing process)

[0052] Next, we will refer to Figure 4 and Figure 5 Describes the processing performed by the AP 103 constructed as described above and Figure 1 The processing sequence performed by the wireless communication system is shown. Figure 4 1 shows a process flow chart after information exchange between APs until data is transmitted from AP 103 (S-AP) to STA 105. When the control unit 302 of AP 103 executes the control program stored in the storage unit 301 and performs calculation and processing of information and control of various hardware, it can be realized Figure 4 Flowchart shown. Figure 5 A sequence diagram showing a process performed by a wireless communication system.

[0053] First, AP 103 decides which communication device among AP 102 to AP 104 should play the role of M-AP (steps S401, F501). The decision process can be decided when AP 103 sends information about AP 103 (including various parameters about AP) to AP 102. In this example, it is decided that AP 102 plays the role of M-AP. That is, each of AP 103 and AP 104 plays the role of S-AP. In the process so far, AP 102 can determine the number of spatial streams (the number of antennas) applicable to each of AP 103 and AP 104 based on the information obtained from AP 103 and AP 104. Next, upon receiving network information such as SSID and BSSID from AP 102 (M-AP) (steps S402, F502), AP 103 sends a beacon to STA 105 according to the received information (F503). Afterwards, based on the transmitted beacon, AP 103 performs connection processing in accordance with the IEEE802.11 series standards with STA 105 (steps S403, F504). AP 103 can directly forward frames received during the connection processing, such as a probe request, an association request, and Auth (authentication), to AP 102. In addition, AP 103 can directly send frames received from AP 102 during the connection processing, such as a probe request, an association request, and an authentication, to STA 105. Like AP 103, AP 104 performs connection processing with STA 105.

[0054] When the connection process is completed, AP 103 sends information about STA 105 (various parameters about STA) to AP 102 (steps S404, F505). The information about STA 105 may include the maximum number of streams applicable to STA 105. Since the maximum number of streams applicable to STA 105 is 8, Figure 1 As described in the description of , this number (representing a value of 8) may be included in the information about STA 105 transmitted from AP 103 to AP 102. Upon receiving the information about STA 105 from AP 103, AP 102 decides the number of streams of STA 105 based on the information (F506).

[0055] Next, AP 103 receives a signal (CSI acquisition instruction) for instructing to obtain CSI (Channel State Indication) from AP 102 (steps S405, F507). AP 104 also receives the CSI acquisition instruction (F507). Thereafter, according to a synchronization signal (not shown) called a trigger frame received from AP 102, AP 103 sends a signal (CSI acquisition request) for requesting STA 105 to obtain CSI (steps S406, F508). Similarly, AP 104 sends a CSI acquisition request to STA 105 (F508). Note that the CSI acquisition instruction sent by AP 102 can play the role of a synchronization signal. Next, AP 103 receives CSI from the connected STA 105 (steps S407, F509), and forwards the received CSI to AP 102 (steps S408, F510). Similarly, AP 104 receives CSI from the connected STA 105 and forwards it to AP 102 (F509 and F510). Based on the CSI received from each of AP 103 and AP 104, AP 102 decides the transmission parameters when sending data to STA 105, including transmission power and transmission timing (F511). The transmission power can be decided for each antenna of the S-AP. AP 102 also decides the stream (spatial stream formed by AP 103 and AP 104 in collaboration) and the number of streams (the number of used streams) to be used when sending data to STA 105. Note that, depending on the situation, the radio waves from AP 103 or AP 104 may not reach STA 105. In this case, the total number of streams when communicating with STA 105 may be less than the number (=8) decided in step S501. In this embodiment, only AP 103 and AP 104 can communicate with STA 105, and AP 102 decides that the number of used streams is 6. This is because the sum of the maximum number of streams of AP 103 (=2) and the maximum number of streams of AP 104 (=4) is 6 (=2+4), which is less than the maximum number of streams (=8) of STA 105. Note that if the sum of the number of streams of AP 103 and AP 104 is greater than the maximum number of streams of STA 105, AP 102 can decide the used stream and the number of used streams based on the received CSI, etc.

[0056] Next, AP 102 determines the power of each antenna of AP 103 and AP 104 when transmitting according to the determined use flow, and transmits a transmission parameter including information indicating the transmission power of each antenna and information indicating the determined number of use flows to AP 103 and AP 104, and AP 103 and AP 104 receive the transmission parameter (step S409, F512). Next, AP 102 transmits data to be transmitted to STA 105 to AP 103 and AP 104, and AP 103 and AP 104 receive the data (step S410, F513). Upon receiving the transmission parameters (step S409, F512) and the data (step S410, F513), each of AP 103 and AP 104 generates a radio frame (the radio frame includes the data and the information of the number of used streams included in the transmission parameters), adjusts the transmission timing according to the reception of the synchronization signal (step S411, F514), and transmits the data to STA 105 in the form of a radio frame (step S412, F515). The data is transmitted by the power set based on the information indicating the transmission power included in the transmission parameters. Note that AP 103 can receive the transmission parameters (step S409), the data (step S410), and the synchronization signal (step S411) at the same time or at different timings. This also applies to AP 104. Note that in the present embodiment, AP 102 (M-AP) determines the transmission power of each of AP 103 and AP 104. Here, AP 103 or AP 104 can decide the transmission power by itself. However, if AP 103 and AP 104 have different gains, the processing in STA 105 may be complicated.

[0057] (Frame structure)

[0058] Figures 6 to 8 An example of a PHY (physical) frame structure of a PPDU defined by the IEEE802.11 EHT standard and transmitted in step S412 or F515 is shown. Note that PPDU is an abbreviation of a physical (PHY) layer protocol data unit. Figure 6 An example of a PHY frame structure of an EHT SU PPDU which is a PPDU for single-user (SU) communication (between an AP and a single STA) is shown. Figure 7 An example of a PHY frame structure of an EHT MU PPDU which is a PPDU for multi-user (MU) communication (between an AP and multiple STAs) is shown. Figure 8 An example of a PHY frame structure of an EHT ER PPDU which is a PPDU for communication in an extended area (communication distance) (extended range) is shown. The EHT ER PPDU is used for communication between an AP and a single STA.

[0059] Usually includes Figures 6 to 8 The information in the PPDU shown is STF (Short Training Field), LTF (Long Training Field) and SIG (Signal Field). Figure 6 For example, the PPDU header includes L (Legacy)-STF 601, L-LTF 602 and L-SIG 603 which are backward compatible with IEEE802.11a / b / g / n / ax standards. L-STF 601 is used to detect PHY frame signals, automatic gain control (AGC), timing detection, etc. L-LTF 602 arranged immediately after L-STF 601 is used to synchronize high-precision frequency / time, obtain propagation channel information (CSI), etc. L-SIG 603 arranged immediately after L-LTF 602 is used to send control information including information such as data transmission rate and PHY frame length. Legacy devices compliant with IEEE802.11a / b / g / n / ax standards can decode the data of the above-mentioned various legacy fields (L-STF 601, L-LTF 602 and L-SIG 603). Various legacy fields are also similarly included in Figure 7 and Figure 8 In the PPDU shown.

[0060] After the above L-STF 601, L-LTF 602 and L-SIG 603, Figure 6 The illustrated EHT SU PPDU includes RL-SIG 604, EHT-SIG-A 605, EHT-STF 606, EHT-LTF 607, data field 608, and packet extension 609. RL-SIG 604 may not exist. EHT-SIG-A 605 is arranged after L-SIG 603, EHT-SIG-B 606 is arranged immediately after EHT-SIG-A 605, and EHT-STF 607 is arranged immediately after EHT-SIG-B 606. Note that the field including L-STF 601, L-LTF 602, L-SIG 603, RL-SIG 604, EHT-SIG-A 605, EHT-SIG-B 606, and EHT-STF 607 is referred to as a preamble. The EHT-SIG-A 605 includes information such as EHT-SIG-A1 and EHT-SIG-A2 required for receiving the PPDU. Subfields forming the EHT-SIG-A1 and EHT-SIG-A2 included in the EHT-SIG-A 605 and descriptions thereof are shown in Tables 1 and 2.

[0061] [Table 1]

[0062]

[0063] [Table 2]

[0064]

[0065] The number of streams for MIMO communication is indicated by the NSTS and midamble periodicity subfield of EHT-SIG-A1, and the possible values ​​vary according to the value of the Doppler field of EHT-SIG-A2. If the value of the Doppler field is 0, it indicates that the mobile speed is low, and the value of the number of streams can be set to 1 to 16. If the value of the Doppler field is 1, it indicates that the mobile speed is high, and the value n of the number of streams is limited to 1 to 4. Note that in this embodiment, 4 bits are allocated to the NSTS and midamble periodicity fields. As an extension of the assumed EHT standard, more than 4 bits (e.g., 5 bits) can be allocated to indicate a number of streams greater than 16.

[0066] In this embodiment, as the number of streams shown in the NSTS and midamble periodicity subfields, the total number of streams (the number of used streams) formed by the APs (AP 103 and AP 104) applicable to D-MIMO for the STA (STA 105) is set. That is, the total number of streams is set, not the number of used streams when the AP 103 or AP 104 itself communicates with the STA 105. In this embodiment, the number of used streams for communication with the STA 105 is determined to be 6 based on the maximum number of streams of the AP 103 (=2) and the maximum number of streams of the AP 104 (=4). Therefore, although the maximum number of streams applicable to the AP 103 is 2, the value input here is 6. The number of used streams set is set based on the number of used streams indicated by the M-AP (AP 102) in step S409 or F512.

[0067] The EHT-STF 606 following the EHT-SIG-A 605 is an abbreviation for the EHT Short Training Field, and its main purpose is to improve automatic gain control in MIMO transmissions. The EHT-LTF 607 is an abbreviation for the EHT Long Training Field, and provides a means for estimating the MIMO channel to the receiver. Note that in Figure 6 In the description of , the number of used flows is set based on the value (information) received from the M-AP. However, not only the number of used flows but all values ​​may be input based on the value received from the M-AP.

[0068] As mentioned above, Figure 8The EHT ER PPDU shown is a PPDU for extending the communication distance and is used for communication between an AP and a single STA. The EHT ER PPDU includes L-STF 801, L-LTF 802, L-SIG 803, RL-SIG 804, EHT-SIG-A 805, EHT-STF 806, EHT-LTF 807, a data field 808, and a packet extension 809. RL-SIG 804 may not exist. L-LTF 802 is arranged immediately after L-STF 801, L-SIG 803 is arranged immediately after L-LTF 802, EHT-SIG-A 805 is arranged after L-SIG 803, EHT-STF 806 is arranged immediately after EHT-SIG-A 805, and EHT-LTF 807 is arranged immediately after EHT-STF 806. Note that the fields including L-STF 801, L-LTF 802, L-SIG 803, RL-SIG 804, EHT-SIG-A 805, EHT-STF 806, and EHT-LTF 807 are referred to as preambles. Information included in each field has the same Figure 6 The same contents are shown in the EHT SU PPDU, and a description thereof will be omitted.

[0069] As mentioned above, Figure 7 The EHT MU PPDU shown is a PPDU used in communication of the MU. The EHT MU PPDU includes L-STF 701, L-LTF 702, L-SIG 703, RL-SIG 704, EHT-SIG-A 705, EHT-SIG-B 706, EHT-STF 707, EHT-LTF 708, data field 709, and packet extension 710. RL-SIG 704 may not exist. The L-LTF 702 is arranged immediately after the L-STF 701, the L-SIG 703 is arranged immediately after the L-LTF 702, the EHT-SIG-A 705 is arranged after the L-SIG 703, the EHT-SIG-B 706 is arranged immediately after the EHT-SIG-A 705, the EHT-STF 707 is arranged immediately after the EHT-SIG-B 706, and the EHT-LTF 708 is arranged immediately after the EHT-STF 707. Note that a field including the L-STF 701, the L-LTF 702, the L-SIG 703, the RL-SIG 704, the EHT-SIG-A 705, the EHT-SIG-B 706, the EHT-STF 707, and the EHT-LTF 708 is referred to as a preamble.

[0070] The EHT-SIG-A 705 includes information such as EHT-SIG-A1 and EHT-SIG-A2 required for receiving the PPDU. Subfields forming the EHT-SIG-A1 and EHT-SIG-A2 included in the EHT-SIG-A 705 and descriptions thereof are shown in Tables 3 and 4.

[0071] [Table 3]

[0072]

[0073] [Table 4]

[0074]

[0075] The EHT-SIG-B 706 includes information such as a common field and a user block field required for receiving the PPDU. Subfields forming the common field and the user block field included in the EHT-SIG-B 706 and their descriptions are shown in Tables 5 and 6.

[0076] [Table 5]

[0077]

[0078] [Table 6]

[0079]

[0080] The format of the user field changes depending on whether transmission is performed to multiple users by OFDMA or MU-MIMO. Table 7 shows the description of the user field in the case of transmission by OFDMA, and Table 8 shows the description of the user field in the case of transmission by MU-MIMO.

[0081] [Table 7]

[0082]

[0083] [Table 8]

[0084]

[0085] The number of streams for MIMO communication is indicated by the NSTS subfield or the spatial configuration subfield in the user field of the EHT-SIG-B. Note that in this embodiment, 4 bits are allocated to the NSTS and midamble periodicity fields. As an extension of the assumed EHT standard, more than 4 bits (e.g., 5 bits) may be allocated to indicate a number of streams greater than 16.

[0086] In the present embodiment, as the number of streams shown in the NSTS subfield or the spatial configuration subfield, the total number of streams (the number of used streams) formed by the APs (AP 103 and AP 104) applicable to D-MIMO for the STA (STA 105) is set (since the streams are used for MU communication, the communication destination may include STAs other than STA 105). That is, the total number of streams is set, rather than the number of used streams when AP 103 or AP 104 itself communicates with STA 105. In this embodiment, the number of used streams used for communication with STA 105 is determined to be 6 based on the maximum number of streams of AP 103 (=2) and the maximum number of streams of AP 104 (=4). Therefore, although the maximum number of streams applicable to AP 103 is 2, the value entered here is 6. The number of used streams set is set based on the number of used streams indicated by the M-AP (AP 102) in step S409 or F512. Note that the information included in each other field is the same as that in FIG. Figure 6 The illustrated EHT SU PPDU has the same content, and a description thereof will be omitted.

[0087] When the frame structure of the PPDU used in the IEEE802.11EHT standard shown in the present invention is used in the above manner to notify the STA of the number of spatial streams formed by multiple S-APs (the number of used streams), the following advantages can be obtained. That is, even if multiple APs actually exist and transmit data to the STA, from the perspective of the STA, the PPDU can be interpreted as if the data is received from a single AP.

[0088] In this embodiment, the number of used streams shown in the PPDU is uniformly managed by the M-AP, and the sum value is sent to the STA. However, other methods may be used. For example, the S-AP may send data including information indicating how many other APs exist together with the number of streams to be used by the S-AP itself. It is believed that the following advantages are obtained thereby. In the case where the synchronization accuracy of the S-AP that sends data to the STA is low, if the total number of APs is unknown, when the data is recovered and received by the STA alone, the data may not be recovered well, or may be interpreted as insufficient data. Even in this case, since the total number of APs communicating with the STA is known, the STA can wait until all data is received, and recover the data or extract the data field after the data becomes analyzable.

[0089] Notice, Figures 6 to 8 The frame structure that is backward compatible with the IEEE802.11a / b / g / n / ax standard is shown. If backward compatibility does not need to be guaranteed, the fields of L-STF and L-LTG can be omitted. Instead, EHT-STF and EHT-LTF can be inserted.

[0090] (Other embodiments)

[0091] The present invention can be implemented by the following processing: providing a program for implementing one or more functions of the above-mentioned embodiment to a system or device via a network or storage medium, and causing one or more processors in a computer of the system or device to read out and execute the program. The present invention can also be implemented by a circuit (such as an ASIC) for implementing one or more functions.

[0092] The present invention is not limited to the above-described embodiments, and various changes and modifications can be made within the spirit and scope of the present invention. Therefore, the claims are made to disclose the scope of the present invention.

Claims

1. A communication device, comprising: A notification section is configured to notify one or more other communication devices different from the communication device of the total number of spatial streams formed by two or more communication devices among the communication device and the one or more other communication devices for communication with a common partner apparatus.

2. The communication device according to claim 1, further comprising: an obtaining unit, configured to obtain, from the one or more other communication devices, the communication quality between the common partner device and the one or more other communication devices; A determination unit is configured to determine the total number of the spatial streams based on the communication quality.

3. A communication device, comprising: a transmitting unit, configured to transmit a physical frame including a preamble and a data field, Wherein, the preamble includes a signal field, and The signal field includes at least a total number of spatial streams formed by two or more communication devices among the communication device and one or more other communication devices different from the communication device for communication with a common partner apparatus.

4. The communication device according to claim 3, wherein: The communication device functions as a slave access point for distributed MIMO, and sets the total number of spatial streams based on an instruction of a master access point for the distributed MIMO.

5. A communication device, comprising: a receiving unit, configured to receive a physical frame including a preamble and a data field, Wherein, the preamble includes a signal field, and The signal field includes at least a total number of spatial streams formed by two or more communication devices among the communication device and one or more other communication devices different from the communication device for communication with a common partner apparatus.

6. The communication device according to any one of claims 3 to 5, wherein: No less than four bits are allocated to a subfield indicating the total number of spatial streams.

7. A communication method performed by a communication device, the communication method comprising: One or more other communication devices other than the communication device are informed of the total number of spatial streams formed by two or more communication devices among the communication device and the one or more other communication devices for communication with a common partner apparatus.

8. The communication method according to claim 7, further comprising: obtaining, from the one or more other communication devices, a communication quality between the common partner apparatus and the one or more other communication devices; The total number of spatial streams is determined based on the communication quality.

9. A communication method performed by a communication device, the communication method comprising: Send a physical frame including the preamble and data field, Wherein, the preamble includes a signal field, and The signal field includes at least a total number of spatial streams formed by two or more communication devices among the communication device and one or more other communication devices different from the communication device for communication with a common partner apparatus.

10. A communication method performed by a communication device, the communication method comprising: receiving a physical frame including a preamble and a data field, Wherein, the preamble includes a signal field, and The signal field includes at least a total number of spatial streams formed by two or more communication devices among the communication device and one or more other communication devices different from the communication device for communication with a common partner apparatus.

11. A computer-readable storage medium storing a program configured to cause a computer to function as the communication device according to any one of claims 1 to 5.

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