Communication device, communication method, and program

Abstract

To properly configure settings for a plurality of access points to send data to a terminal in parallel.SOLUTION: In a communication device that transmits a radio frame having a physical layer (PHY) preamble and a data field, the preamble contains a field to set the first Basic Service Set (BSS) color, and the first BSS color field is set to a value depending on whether the communication device and the first other communication device cooperate to transmit a wireless frame to the second other communication device.SELECTED DRAWING: Figure 7

Description

Technical Field

[0001] The present invention relates to communication control technology in a wireless LAN.

Background Art

[0002] As a communication standard for a wireless LAN (Wireless Local Area Network), the IEEE (Institute of Electrical and Electronics Engineers) 802.11 standard is known. In the IEEE 802.11ax standard, which is the latest standard in the IEEE 802.11 standard series, by using OFDMA (Orthogonal Frequency Division Multiple Access), in addition to high peak throughput, an improvement in communication speed under congested conditions is achieved (see Patent Document 1).

[0003] Currently, for further throughput improvement, as a successor standard to IEEE 802.11ax, a Study Group called IEEE 802.11EHT (Extremely High Throughput) has been formed. In EHT, in order to achieve throughput improvement, a Multi-AP Coordination configuration is being considered in which a plurality of spatially distributed access points (APs) cooperate to transmit data to a single STA (Station).

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] In the IEEE 802.11ax standard, it is specified to use identification information called BSS (Basic Service Set) color. When a communication device receives a wireless frame with the same BSS color as the BSS color of the AP to which the device is connected, the communication device treats the wireless frame as an Intra-BSS frame. On the other hand, in IEEE 802.11EHT, although it is being considered to use the Multi-AP Coordination configuration as described above, it is not clear how the BSS color should be set in this case.

[0006] The present invention provides a method for appropriately executing settings for a plurality of access points to transmit data to a terminal in parallel.

Means for Solving the Problems

[0007] A communication device according to an aspect of the present invention is a communication device having transmission means for transmitting a wireless frame having a preamble and a data field in a physical layer (PHY), wherein the preamble includes a field for setting a first Basic Service Set (BSS) color, and a value corresponding to whether the communication device and a first other communication device cooperate to transmit the wireless frame to a second other communication device is set in the first BSS color field.

Advantages of the Invention

[0008] According to the present invention, settings for a plurality of access points to transmit data to a terminal in parallel can be appropriately executed.

Brief Description of the Drawings

[0009]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, embodiments will be described in detail with reference to the accompanying drawings. Note that the following embodiments do not limit the invention according to the claims. Although a plurality of features are described in the embodiments, not all of these plurality of features are essential to the invention, and the plurality of features may be arbitrarily combined. Further, in the accompanying drawings, the same or similar configurations are denoted by the same reference numerals, and redundant descriptions are omitted.

[0011] (Network Configuration) FIG. 1 shows a configuration example of the wireless communication network of the present embodiment. This wireless communication network includes access points (AP102, AP104) and terminals (STA103, STA105), each of which is an IEEE802.11EHT (Extremely High Throughput) device. Hereinafter, when not referring to a specific device, the access point may be referred to as "AP" and the station may be referred to as "STA" without a reference number. Note that FIG. 1 shows a wireless communication network including two APs and two STAs as an example, but the number of these communication devices may be three or more, for example. In FIG. 1, the communicable range of the network formed by AP102 and AP104 is indicated by circle 101. Note that this communicable range may cover a wider range or only a narrower range. Also, in FIG. 1, an STA compliant with the IEEE802.11EHT standard is illustrated, but there may be an STA that supports only a previous generation standard (legacy standard) prior to the IEEE802.11EHT standard. Note that EHT may be understood as an abbreviation for Extreme High Throughput.

[0012] In this example, it is assumed that AP102 and AP104 can receive signals transmitted by the other AP. Note that the connection form is not particularly limited, and AP102 and AP104 may be connected by wire or wirelessly. AP102 and AP104 support the Multi-AP Coordination configuration of IEEE802.11EHT and are assumed to be able to cooperate with each other to transmit data to one STA in parallel. For example, STA105 can transmit and receive wireless frames in parallel between AP102 and AP104 that operate in cooperation. STA105 can be configured to have, for example, a plurality of wireless LAN control units and be able to transmit and receive wireless frames using different wireless channels between the plurality of APs. Note that STA105 may have a physically single control unit that can process a plurality of frames received in parallel via a plurality of wireless channels. That is, STA105 has a configuration that can logically process a plurality of wireless communications in parallel using one or a plurality of physical control devices.

[0013] (Device Configuration) Figure 2 shows the hardware configurations of APs (AP102, AP104) and STAs (STA103, STA105). As an example of their hardware configurations, these communication devices have a storage unit 201, a control unit 202, a functional unit 203, an input unit 204, an output unit 205, a communication unit 206, and an antenna 207.

[0014] The storage unit 201 is composed of both a ROM and a RAM, or either one of them, and stores programs for performing various operations described later and various information such as communication parameters for wireless communication. Note that, as the storage unit 201, in addition to memories such as ROM and RAM, storage media such as flexible disks, hard disks, optical disks, magneto-optical disks, CD-ROMs, CD-Rs, magnetic tapes, non-volatile memory cards, and DVDs may be used.

[0015] The control unit 202 is composed of, for example, a processor such as a CPU or MPU, an ASIC (Application Specific Integrated Circuit), a DSP (Digital Signal Processor), an FPGA (Field Programmable Gate Array), etc. Here, CPU is the acronym for Central Processing Unit, and MPU is the acronym for Micro Processing Unit. The control unit 202 controls the entire device by executing the program stored in the storage unit 201. Note that the control unit 202 may control the entire device in cooperation with the program stored in the storage unit 201 and the OS (Operating System).

[0016] Also, the control unit 202 controls the functional unit 203 to execute predetermined processes such as imaging, printing, and projection. The functional unit 203 is the hardware for the device to execute predetermined processes. For example, when the device is a camera, the functional unit 203 is an imaging unit and performs imaging processing. Also, for example, when the device is a printer, the functional unit 203 is a printing unit and performs printing processing. Also, for example, when the device is a projector, the functional unit 203 is a projection unit and performs projection processing. The data processed by the functional unit 203 may be the data stored in the storage unit 201, or may be the data communicated with other APs or STAs via the communication unit 206 described later.

[0017] The input unit 204 receives various operations from the user. The output unit 205 performs various outputs to the user. Here, the output by the output unit 205 includes, for example, at least one of display on the screen, audio output by the speaker, vibration output, etc. Note that both the input unit 204 and the output unit 205 may be realized by one module such as a touch panel.

[0018] The communication unit 206 controls wireless communication compliant with the IEEE 802.11 standard series and controls IP communication. In this embodiment, the communication unit 206 can execute at least processes compliant with the IEEE 802.11 EHT standard. Also, the communication unit 206 controls the antenna 207 to transmit and receive radio signals for wireless communication. The device communicates contents such as image data, document data, and video data with other communication devices via the communication unit 206. The antenna 207 is, for example, an antenna capable of transmitting and receiving at least any one of the sub-GHz band, 2.4 GHz band, 5 GHz band, and 6 GHz band. Note that the frequency band (and its combination) supported by the antenna 207 is not particularly limited. The antenna 207 may be a single antenna or a set of two or more antennas for performing MIMO (Multi-Input and Multi-Output) transmission and reception. Also, in FIG. 2, a single antenna 207 is shown, but it may include two or more (two sets or more) antennas each capable of corresponding to different frequency bands, for example. The antenna 207 is configured to be capable of corresponding to the communication of Distributed Coordinaiton of the IEEE 802.11 EHT standard. For example, the AP has a configuration such that D-MIMO (Distributed MIMO) transmission for JTX (Joint Transmission) is possible.

[0019] Note that JTX is one of the elements for implementing the Multi-AP Coordination function newly introduced from IEEE802.11EHT, which refers to the case where multiple APs cooperate to transmit data to one STA in parallel. The Multi-AP Coordination function is a function in which multiple APs cooperate to improve the throughput and signal strength of transmission and reception on the STA side. As the wireless technology at this time, D-MIMO can be used. D-MIMO is a technology in which multiple APs communicate with one STA at the same time and on the same frequency channel (for example, the same RU (Resource Unit) of OFDMA (Orthogonal Frequency Division Multiple Access)). According to D-MIMO, high-speed communication can be realized by improving the spatial utilization efficiency. The minimum configuration of D-MIMO consists of an M-AP (Master AP), an S-AP (Slave AP), and an STA. In this case, under the control of the M-AP, two APs, the M-AP and the S-AP, cooperate to transmit wireless frames to one STA in parallel (simultaneously).

[0020] Fig. 3 shows a functional configuration example of the APs (AP102, AP104). As an example, the AP has a wireless LAN control unit 301, a frame generation unit 302, a BSS color setting unit 303, a UI control unit 304, a storage unit 305, and an antenna 306.

[0021] The wireless LAN control unit 301 includes a circuit for transmitting and receiving wireless signals to and from other wireless LAN devices (e.g., other APs or STAs) and a program for controlling them. The wireless LAN control unit 301 executes wireless LAN communication control such as transmitting the frames generated by the frame generation unit 302 and receiving wireless frames from other wireless LAN devices in accordance with the IEEE802.11 standard series. The frame generation unit 302 generates a wireless frame to be transmitted by the wireless LAN control unit 301 based on, for example, data received from another AP and to be transmitted to the STA. Further, the frame generation unit 302 generates, for example, a wireless frame including data to be transmitted to the STA by another AP or a trigger frame (JTX TF) for instructing the timing at which the wireless frame including the data should be transmitted to the STA.

[0022] The BSS color setting unit 303 sets the BSS color of the wireless frame. When the own device (AP102 or AP104) constructs a BSS (Basic Service Set), for example, the BSS color setting unit 303 sets the BSS color to be used in that BSS. Then, the BSS color setting unit 303 sets the value of the BSS color for the wireless frame transmitted to the STA connected to the own device. On the other hand, when performing data transmission by JTX to the STA connected to another AP, the BSS color setting unit 303 sets the BSS color used in the BSS constructed by this other AP for the wireless frame transmitted to that STA. That is, when transmitting a wireless frame to a STA connected to another AP different from the own device by JTX, the BSS color setting unit 303 uses the BSS color of the other AP regardless of the BSS color used in the BSS constructed by the own device. According to this, a plurality of wireless frames received at the STA can be made into wireless frames with the BSS color set that is used in the BSS to which the STA is connected. For this reason, the STA can handle all the plurality of wireless frames received from a plurality of APs as Intra-BSS frames. On the other hand, for wireless frames other than those by JTX, since the BSS color setting unit 303 sets the BSS color of the BSS constructed by the own device, a STA connected to another AP can handle that wireless frame as an Inter-BSS frame. Note that the STA can execute different controls depending on whether the received wireless frame is an Intra-BSS frame or an Inter-BSS frame. For example, the STA can transmit a wireless frame when the received power of the wireless frame does not exceed a predetermined value, but can set the predetermined value for the Inter-BSS frame to be higher than the predetermined value for the Intra-BSS frame. According to this, even when the wireless frame is received with power exceeding the predetermined value for the Intra-BSS frame, if the wireless frame is an Inter-BSS wireless frame, there may be a case where the STA can obtain a transmission opportunity.Therefore, by having the AP use a BSS color different from other APs except during JTX, the communication opportunities of STAs connected to other APs can be increased, and the frequency utilization efficiency of the entire system can be improved.

[0023] The UI control unit 304 is configured to include hardware such as a touch panel or buttons for receiving operations on the AP by users (not shown) of the AP, which are user interfaces (UIs), and programs for controlling them. Note that the UI control unit 304 also has functions for presenting information to the user, such as displaying images or outputting sound. The storage unit 305 is configured to include storage devices such as a ROM (Read Only Memory) and a RAM (Random Access Memory) for storing programs and various data executed by the AP.

[0024] Note that the STA has functions as a general STA. However, the STA may have a function of receiving wireless frames transmitted in a Multi-AP Coordination configuration.

[0025] (Frame Structure) Examples of the structure of a PPDU (Physical layer (PHY) Protocol Data Unit) compliant with the IEEE802.11EHT standard will be described with reference to FIGS. 4 to 6. FIG. 4 shows an example of an EHT SU (Single User) PPDU, which is a PPDU for single-user communication. FIG. 5 shows an example of an EHT MU (Multi User) PPDU for multi-user communication. FIG. 6 shows an example of an EHT ER (Extended Range) PPDU for long-distance transmission. The EHT ER PPDU is used when the communication range needs to be extended in communication between an AP and a single STA. Note that the fields of the PPDU do not necessarily have to be arranged in the order shown in FIGS. 4 to 6, and may include new fields not shown in FIGS. 4 to 6.

[0026] The PPDU includes fields such as STF (Short Training Field), LTF (Long Training Field), and SIG (Signal Field). As shown in Figure 4, at the head of the PPDU, there are L (Legacy)-STF401, L-LTF402, and L-SIG403 for ensuring backward compatibility with the IEEE802.11a / b / g / n / ax standards. In the frame formats of Figures 5 and 6 as well, L-STF (L-STF501 and L-STF601), L-LTF (L-LTF502 and L-LTF602), and L-SIG (L-SIG503 and L-SIG603) are included. Note that L-LTF is arranged immediately after L-STF, and L-SIG is arranged immediately after L-LTF. In the configurations of Figures 4 to 6, further, RL-SIG (Repeated L-SIG, RL-SIG404, RL-SIG504, RL-SIG604) arranged immediately after L-SIG is included. In the RL-SIG field, the content of L-SIG is repeatedly transmitted. RL-SIG enables the receiver to recognize that the PPDU complies with standards after the IEEE802.11ax standard, and in some cases, it may be omitted in IEEE802.11EHT. Also, instead of RL-SIG, a field for enabling the receiver to recognize that the PPDU is an IEEE802.11EHT PPDU may be provided.

[0027] L-STF401 is used for detecting physical layer (PHY) frame signals, automatic gain control (AGC), and timing detection. L-LTF402 is used for high-precision synchronization of frequency and time, and obtaining propagation channel information (CSI: Channel State Information). L-SIG403 is used for transmitting control information including data transmission rate and PHY frame length information. Legacy devices compliant with the IEEE802.11a / b / g / n / ax standards can decode the above various legacy fields.

[0028] Each PPDU further includes an EHT-SIG (EHT-SIG-A405, EHT-SIG-A505, EHT-SIG-B506, EHT-SIG-A605) for transmitting control information for EHT, which is arranged immediately after the RL-SIG. Also, each PPDU has an EHT-STF (EHT-STF406, 507, 606) and an EHT-LTF (EHT-LTF407, 508, 607) for EHT. Each PPDU has data fields 408, 509, 608 and Packet extention fields 409, 710, 609 after these control fields. The fields from the L-STF to the EHT-LTF of each PPDU are called the PHY preamble.

[0029] Note that FIGS. 4 to 6 show, as an example, PPDUs that can ensure backward compatibility. However, when backward compatibility does not need to be ensured, for example, legacy fields may be omitted. In this case, for example, to establish synchronization, instead of the L-STF and L-LTF, the EHT-STF or EHT-LTF may be used. And in this case, one of the EHT-STF or a plurality of EHT-LTFs after the EHT-SIG field may be omitted.

[0030] The EHT-SIG-A405 and 605 included in the EHT SU PPDU and the EHT ER PPDU include the EHT-SIG-A1 and EHT-SIG-A2 necessary for receiving the PPDU, as shown in Tables 1 and 2 below. The EHT-SIG-A1 includes a 6-bit "BSS color" subfield. Also, the EHT-SIG-A505 of the EHT MU PPDU in FIG. 5 also includes the EHT-SIG-A1 and EHT-SIG-A2 necessary for receiving the PPDU, as shown in Tables 3 and 4 below. And in this PPDU as well, the EHT-SIG-A1 includes a 6-bit "BSS color" subfield. Note that the configurations of Tables 1 to 4 are only examples, and information other than the information shown in these tables may be included in the EHT-SIG field, or some of the information shown in these tables may be excluded from the EHT-SIG field.

[0031] [Table 1]

[0032] [Table 2]

[0033] [Table 3]

[0034] [Table 4]

[0035] (Processing flow) Subsequently, with reference to FIGS. 7 and 8, an example of the processing flow executed by the AP as described above and an example of the processing flow executed in the wireless communication network will be described. FIG. 7 shows an example of the processing flow in the wireless communication network, and FIG. 8 shows an example of the processing flow executed by the APs 102 and 104.

[0036] First, the AP 102 constructs the first BSS (BSS1) (F701, S801). In this embodiment, it is assumed that in BSS1, a setting using BSS color1 is performed. Also, the AP 104 constructs the second BSS (BSS2) (F702, S801). Here, in this embodiment, it is assumed that in BSS2, a setting using a BSS color2 different from BSS color1 is performed. Each AP notifies the IEEE 802.11 Beacon at a fixed period and accepts connection requests from STAs, thereby mediating communication between an STA and another STA or between an STA and the DS (Distribution System).

[0037] AP102 executes a connection procedure with STA103 and transitions to a connected state (F703). Similarly, it is assumed that AP104 executes a connection procedure with STA105 and transitions to a connected state (F704). In this connection procedure, as in the case of IEEE802.11ax, operation state information is notified from the AP to the STA. This operation state information includes the value of the BSS color. The BSS color is 6-bit information that identifies the BSS included in the preamble of the physical layer (PHY) as described above. Based on the value of the BSS color, the STA can determine whether the received wireless frame is a frame of the BSS (intra-BSS) to which it belongs or a frame of a BSS (inter-BSS) to which it does not belong.

[0038] AP102 can transmit a wireless frame to STA103 (F705). This wireless frame is a PPDU shown in any of FIGS. 4 to 6, and a value indicating BSS color1 used in BSS1 is stored in the BSS color subfield. Similarly, AP104 can transmit a wireless frame to STA105 (F706). This wireless frame is also a PPDU shown in any of FIGS. 4 to 6, and a value indicating BSS color2 used in BSS2 is stored in the BSS color subfield. As shown in the above table, the BSS color subfield is bits 9 to 14 (B8 to B13) of EHT-SIG-A1 in the case of EHT SU PPDU and EHT ER PPDU. Also, the BSS color subfield is bits 6 to 11 (B5 to B10) of EHT-SIG-A1 in the case of EHT MU PPDU.

[0039] Thereafter, it is assumed that AP102 and AP104 have decided to cooperate to perform data transmission to a common STA in parallel. For example, when AP104 detects that there is a large amount of data to be transmitted to STA105, it can decide to cooperate with AP102, which is another AP present in the vicinity, to transmit data to STA105 in parallel. Also, even if there is no plan for large-capacity data communication to a specific STA, for example, AP102 or AP104 may decide to make preparations for cooperative transmission with other APs in anticipation of future large-capacity data communication. When it is determined that cooperative transmission by multiple APs will be performed or preparations therefor will be made, AP102 and AP104 perform negotiation for JTX (Joint Transmission) (F707, S802). Hereinafter, the negotiation for JTX may be simply referred to as "negotiation". In the negotiation, the AP that executes the negotiation can determine whether it will operate in the role of either M-AP or S-AP. Here, it is assumed that it has been determined that AP102 will operate as M-AP (YES in F708, S803), and it has been determined that AP104 will operate as S-AP (NO in F709, S803). Also, in this negotiation, it may be determined which AP will associate with the STA that is the target of JTX.

[0040] After the negotiation ends, AP104, which is an S-AP, notifies AP102, which is an M-AP, of the information of STA105 connected to its own device and the information of BSS color2 used in BSS2 constructed by its own device (F710, S804, S811). Here, the STA information may include information such as the MAC (Media Access Control) address of the STA. Note that these pieces of information may be notified from the S-AP to the M-AP at other timings, such as being exchanged between APs at the time of negotiation. Also, AP102 may notify AP104 of the information of STA103 connected to its own device and the information of BSS color1 used in BSS1 constructed by its own device. Furthermore, when AP102 and AP104 perform JTX to transmit data to a specific STA, the information of that STA and the BSS color information may be notified from the AP connected to that STA to the other AP. However, since the M-AP can specify the STA and BSS color for data transmission in the transmission of data to be transmitted and JTX trigger frames, etc., which will be described later, it may not be necessary to provide information from the M-AP to the S-AP at this point.

[0041] After that, AP102 notifies AP104, which operates as an S-AP, of the start of the JTX mode (F711, S805, S812). After that, when data to be transmitted to STA105 is generated (YES in S806), the data to be transmitted is sent from AP102 to AP104 (F712, S807, S813). Since AP104 is operating in the JTX mode, it does not immediately transmit the received data to STA105 but temporarily holds the received data.

[0042] In addition, when transmitting the transmission target data from the M-AP to the S-AP, the information on the BSS color to be used may be notified from the M-AP to the S-AP. In this embodiment, since data is transmitted to the STA105 by JTX, the BSS color2 used in the AP104 to which the STA105 is connected can be notified as the information on the BSS color to be used. In addition, when the BSS color to be used matches the BSS color used in the S-AP or when the BSS color used in JTX is known in advance, the information on the BSS color may not be notified from the M-AP to the S-AP. That is, the M-AP does not have to notify the S-AP of the information on the BSS color when transmitting data to the STA connected to the S-AP by JTX or when the information on the BSS color is exchanged with the STA that is the target of data transmission by JTX. For example, when data is transmitted to the STA103 by JTX, the BSS color1 can be notified from the AP102 to the AP104 as the information on the BSS color to be used. When the data is transmitted by the above-mentioned PPDU, since the PPDU includes a PHY preamble that notifies the BSS color, the information on the BSS color to be used is naturally notified. In this case, the S-AP receives a radio frame in which a BSS color different from the BSS color used by the own device is set, but since it is operating in the JTX mode, the data in this radio frame is not discarded.

[0043] After the transmission and reception of the data to be transmitted, in order to cause AP102 to transmit a wireless frame including this data to be transmitted, AP102 transmits a JTX trigger frame (TF) to AP104 (F713, S808, S814). AP102 can instruct AP104 to transmit a wireless frame to STA105 by the JTX TF and specify the timing of the transmission. Then, AP102 and AP104 transmit data to STA105 in parallel at the timing specified by, for example, the JTX TF (YES in S809) (F714, F715, S810). Note that the transmission timing can be after a predetermined time (SIFS, Short Inter Frame Space) has elapsed since the transmission and reception of the JTX TF. In this case, the transmission timing is indicated by the transmission and reception of the JTX TF itself. In this case, the JTX TF can be transmitted at a timing corresponding to the timing at which AP102 and AP104 should transmit a wireless frame to STA105. Also, information specifying the transmission timing may be included in the frame of the JTX TF. In this case, AP102 and AP104 can determine when to transmit a wireless frame using the specified transmission timing and a timer, clock, etc. in their own devices. In this way, AP102 and AP104 can transmit wireless frames synchronously using the JTX TF.

[0044] In the data transmission at this time, the BSS color used in the BSS (AP to which the STA is connected) to which the STA targeted for data transmission belongs is set in the PHY preamble in the wireless frame. In the example of FIG. 7, the BSS color2 used in BSS2 to which the STA105 targeted for data transmission belongs is set in the wireless frame. That is, the AP104 transmits the wireless frame using the BSS color2 used by its own device as it is, while the AP102 transmits the wireless frame using a BSS color2 different from the BSS color1 used by its own device. However, the BSS color of BSS1 constructed by the AP102 is not changed from BSS color1. That is, the AP102 does not change the BSS color of the BSS constructed by its own device, but when transmitting data in JTX, it sets the BSS color used in the BSS to which the destination STA of the data belongs in the wireless frame and transmits it. At this time, even when operating in the JTX mode, the AP102 can transmit data to the STA (STA103) connected to its own device. In this case, the AP102 can transmit data by setting the BSS color1 used in BSS1 constructed by its own device in the wireless frame. That is, when operating in the JTX mode, the AP102 sets the BSS color of the BSS to which the STA belongs in the wireless frame and transmits it. The same applies to the AP104. That is, the AP104 uses the BSS color2 in BSS2 constructed by its own device, but for example, when instructed by the AP102 to transmit data to the STA103 in JTX, it can transmit a wireless frame with the BSS color1 set to the STA103. At this time, the AP104 does not change the BSS color of BSS2.

[0045] By doing so, each AP does not change the BSS color in the BSS constructed by its own device, so it will not instruct the connected STA to change the BSS color. Therefore, it is not necessary to change the settings of the STA unnecessarily, and for example, an increase in the power consumption of the STA can be suppressed. On the other hand, at the time of JTX, in accordance with the BSS to which the STA belongs, since the BSS color in the PHY preamble of the wireless frame is set, the STA can receive the wireless frame without changing the setting of the BSS color at the time of JTX.

[0046] The present invention can also be realized by supplying a program that realizes one or more functions of the above-described embodiments to a system or device via a network or a storage medium, and having one or more processors in the computer of the system or device read and execute the program. It can also be realized by a circuit (for example, ASIC) that realizes one or more functions.

[0047] The invention is not limited to the above-described embodiments, and various changes and modifications are possible without departing from the spirit and scope of the invention. Therefore, claims are attached to disclose the scope of the invention.

Explanation of Reference Numerals

[0048] 102, 104: AP, 103, 105: STA, 301: Wireless LAN control unit, 302: Frame generation unit, 303: BSS color setting unit, 304: UI control unit, 305: Storage unit

Claims

1. Construction means for constructing a first Basic Service Set (BSS), Transmission means for transmitting a wireless frame having a preamble and a data field of a physical layer (PHY), A communication device having, The preamble is, Legacy Short Training Field (L-STF), Legacy Long Training Field (L-LTF) arranged immediately after the L-STF in the wireless frame, Legacy Signal Field (L-SIG) arranged immediately after the L-LTF in the wireless frame, Extremely High Throughput (EHT) Signal Field (EHT-SIG-A) arranged after the L-SIG in the wireless frame, EHT Short Training Field (EHT-STF) arranged immediately after the EHT-SIG-A in the wireless frame, EHT Long Training Field (EHT-LTF) arranged immediately after the EHT-STF in the wireless frame, Including, The EHT-SIG-A includes a subfield for setting a BSS color, When the communication device and a first other communication device cooperate to transmit the wireless frame to a second other communication device, without changing the BSS color used in the first BSS, based on the BSS color of the second BSS to which the second other communication device belongs, the value of the subfield is set. A communication device characterized by the above.

2. When the second BSS is a third BSS constructed by the first other communication device, the BSS color used in the third BSS is set as the value of the subfield. The communication device according to claim 1, characterized by this.

3. The communication device obtains information on the BSS color of the third BSS from the first other communication device. The communication device according to claim 2, characterized by this.

4. When the second BSS is the third BSS, the communication device obtains information on the second other communication device from the first other communication device. The communication device according to claim 2 or 3, characterized by this.

5. When the second BSS is the first BSS, the BSS color used in the first BSS is set as the value of the subfield. The communication device according to any one of claims 1 to 4, characterized in that.

6. The communication device notifies the first other communication device of the information on the BSS color of the first BSS. The communication device according to any one of claims 1 to 5, characterized in that.

7. When the second BSS is the first BSS, the communication device notifies the first other communication device of the information on the second other communication device. The communication device according to claim 5, characterized in that.

8. While the communication device is operating in a mode of transmitting the wireless frame in cooperation with the first other communication device, based on the BSS color of the BSS to which the destination device of the wireless frame belongs, the value of the subfield is set. The communication device according to any one of claims 1 to 7, characterized in that.

9. While the communication device is not operating in the mode, based on the BSS color of the first BSS, the value of the subfield is set. The communication device according to claim 8, characterized in that.

10. The communication device and the first other communication device are access points compliant with IEEE 802.11 EHT, and the second other communication device is a station compliant with IEEE 802.11 EHT. The communication device according to any one of claims 1 to 9, characterized in that.

11. A communication method executed by a communication device that constructs a first Basic Service Set (BSS), including a transmission step of transmitting a wireless frame having a preamble and a data field in a physical layer (PHY), The preamble is a Legacy Short Training Field (L-STF), a Legacy Long Training Field (L-LTF) arranged immediately after the L-STF in the wireless frame, a Legacy Signal Field (L-SIG) arranged immediately after the L-LTF in the wireless frame, an Extremely High Throughput (EHT) Signal Field (EHT-SIG-A) arranged after the L-SIG in the wireless frame, An EHT Short Training Field (EHT-STF) arranged after the EHT-SIG-A in the wireless frame, and an EHT Long Training Field (EHT-LTF) arranged immediately after the EHT-STF in the wireless frame, are included, the EHT-SIG-A includes a subfield for setting a BSS color, when the communication device and a first other communication device cooperate to transmit the wireless frame to a second other communication device, the value of the subfield is set based on the BSS color of a second BSS to which the second other communication device belongs without changing the BSS color used in the first BSS. A communication method characterized by the above. **Claim 12** A program for causing a computer to function as each means included in the communication device according to any one of Claims 1 to 10.

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