Access point device, station device, and communication method

Abstract

To provide an access point device, a station device, and a communication method that contribute to effective utilization of frequency resources.SOLUTION: A wireless communication device 10000-1 is a station device that connects to an access point device, and includes a receiving unit that receives a first frame, and a transmitting unit that transmits a response frame to the first frame in a second frequency band that is the same as or different from a first frequency band in which the first frame is received. The transmitting unit can contribute to effective utilization of frequency resources by using different transmission power when transmitting the response frame in the first frequency band and when transmitting the response frame in the second frequency band.SELECTED DRAWING: Figure 6

Description

[Technical field]

[0001] The present invention relates to an access point device, a station device, and a communication method. [Background technology]

[0002] The Institute of Electrical and Electronics Engineers Inc. (IEEE) is continuously working on updating the specifications of IEEE 802.11, the standard for wireless LAN (Local Area Network), to realize faster wireless LAN communication and more efficient frequency utilization. Wireless LAN can perform wireless communication using unlicensed bands that can be used without permission (license) from a country or region. For personal use such as at home, wireless Internet access from within the home has been made wireless by including a wireless LAN access point function in a line termination device for connecting to a WAN (Wide Area Network) line to the Internet, or by connecting a wireless LAN access point device to the line termination device.

[0003] The IEEE 802.11ax specification will be completed in 2021, and wireless LAN devices compliant with the specification will appear on the market. Currently, standardization activities for IEEE 802.11be, the successor standard to IEEE 802.11ax, are underway, and discussions are also underway for its successor, IEEE 802.11bn. With the rapid spread of wireless LAN devices, recent IEEE 802.11 standardization has been examining how to further improve throughput per user in environments where wireless LAN devices are densely deployed.

[0004] In the IEEE 802.11be standardization, there is a discussion on multi-link operation (MLO) that enables a communication device to maintain multiple link connections using multiple frequency bands (see Non-Patent Document 1). As an example of MLO, three link connections, namely, a 2.4 GHz band connection, a 5 GHz band connection, and a 6 GHz band connection, are operated simultaneously. Of course, the combinations of frequency bands, channels, and subchannels are not limited to these combinations, and there are various combinations. From the viewpoint of frequency bands, in the future, high frequency bands such as millimeter waves (45 GHz band, 60 GHz band, etc.) and (sub) terahertz waves (100 GHz to 300 GHz band) can also be used as one link constituting a Multi-Link. According to MLO, a communication device can maintain multiple link connections with different settings related to wireless resources and communication used. That is, by using MLO, a communication device can simultaneously maintain link connections of different frequency bands. Not only can frames be transmitted and received using multiple links simultaneously, but it is also possible to switch link connections for transmitting and receiving frames (change frequency bands) without performing a reconnection operation. The links constituting the multiple links (multi-link) here are also called physical layer links. [Prior art documents] [Non-patent literature]

[0005] [Non-Patent Document 1] IEEE 802.11-19 / 0773-08-00be, Nov.2019 Summary of the Invention [Problem to be solved by the invention]

[0006] High frequency bands can achieve high throughput because they can secure a wide bandwidth per channel. On the other hand, high frequency bands have large radio wave propagation losses (path losses), so it is essential to use beamforming to compensate for the path losses. However, achieving high-precision beamforming requires advanced hardware and signal processing, which suggests the challenge of how difficult it is for terminal devices, which require low power consumption and compact size, to be equipped with high-quality high-frequency band transceivers. [Means for solving the problem]

[0007] In order to solve the above-mentioned problems, an access point device, a station device, and a communication method according to the present invention are as follows.

[0008] (1) That is, a station device according to one embodiment of the present invention is a station device that connects to an access point device, and includes a receiving unit that receives a first frame, and a transmitting unit that transmits a response frame of the first frame in a second frequency band that is the same as or different from a first frequency band in which the first frame is received, and the transmitting unit has different transmission power when transmitting the response frame in the first frequency band and when transmitting the response frame in the second frequency band.

[0009] (2) Furthermore, a station device according to one embodiment of the present invention is described in (1) above, and when the transmitting unit transmits the response frame in the second frequency band, if the second frequency band includes a frequency lower than the first frequency band, the transmission power is lower than when the transmitting unit transmits the response frame in the first frequency band.

[0010] (3) Moreover, a station device according to an embodiment of the present invention is as described in (1) above, in which the transmission power of the response frame is equal to or lower than a CCA level set in the BSS to which the station device belongs.

[0011] (4) Furthermore, a station device according to one embodiment of the present invention is described in (1) above, and acquires from the access point device information associated with an interference power tolerated by the access point device, and the transmission power of the response frame is lower than the allowable transmission power calculated from the information associated with the interference power.

[0012] (5) Furthermore, a station device according to one embodiment of the present invention is described in (1) above, and a first response time range for transmitting the response frame in the first frequency band and a second response time range for transmitting the response frame in the second frequency band are each set, and the set value of the second response time range is wider than the set value of the first response time range.

[0013] (6) Furthermore, a station device according to one embodiment of the present invention is described in (1) above, connects to a BSS consisting of a plurality of access point devices including the access point device, and transmits the response frame to the first frame transmitted from the access point device to at least one of the plurality of access point devices other than the access point device included in the BSS.

[0014] (7) Furthermore, an access point device according to one embodiment of the present invention is an access point device connected to a station device, and includes a transmitter that transmits a first frame, and a receiver that receives a response frame to the first frame in a second frequency band that is the same as or different from a first frequency band in which the first frame is transmitted, and a transmission power set in the response frame when transmitted in the first frequency band is different from a transmission power set in the response frame when transmitted in the second frequency band.

[0015] (8) Also, a communication method according to one embodiment of the present invention is a communication method for a station device connecting to an access point device, comprising the steps of receiving a first frame and transmitting a response frame for the first frame in a second frequency band that is the same as or different from a first frequency band in which the first frame is received, and wherein a transmission power is different when transmitting the response frame in the first frequency band and when transmitting the response frame in the second frequency band. Effect of the Invention

[0016] According to the present invention, a station device supporting a high frequency band can perform frame exchange using the high frequency band with high efficiency, thereby contributing to the effective use of frequency resources. [Brief description of the drawings]

[0017] [Figure 1] FIG. 2 is a diagram illustrating an example of a frame configuration according to an embodiment of the present invention. [Diagram 2] FIG. 2 is a diagram illustrating an example of a frame configuration according to an embodiment of the present invention. [Diagram 3] FIG. 2 is a diagram illustrating an example of communication according to an embodiment of the present invention. [Figure 4] FIG. 2 is a schematic diagram illustrating an example of division of radio resources according to an aspect of the present invention. [Diagram 5] FIG. 1 is a diagram illustrating an example of a configuration of a communication system according to an aspect of the present invention. [Figure 6] 1 is a block diagram showing an example of a configuration of a wireless communication device according to an aspect of the present invention. [Figure 7] 1 is a block diagram showing an example of a configuration of a wireless communication device according to an aspect of the present invention. [Figure 8] FIG. 2 is a diagram illustrating an example of a frame configuration according to an embodiment of the present invention. [Figure 9] 1 is a block diagram showing an example of a configuration of a wireless communication device according to an aspect of the present invention. [Figure 10] FIG. 2 is a diagram illustrating frame transmission and reception according to an embodiment of the present invention. [Figure 11]FIG. 2 is a schematic diagram illustrating frame transmission and reception according to an aspect of the present invention. [Figure 12] FIG. 2 is a schematic diagram illustrating frame transmission and reception according to an aspect of the present invention. [Figure 13] FIG. 2 is a schematic diagram illustrating frame transmission and reception according to an aspect of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0018] The communication system in this embodiment includes an access point device (also referred to as a base station device) and multiple station devices (also referred to as terminal devices). A communication system or network configured with the access point device and the station devices is called a basic service set (BSS: Basic service set, management range). The station device according to this embodiment can have the functions of an access point device. Similarly, the access point device according to this embodiment can have the functions of a station device. Therefore, hereinafter, when simply referring to a communication device or a wireless communication device, the communication device or wireless communication device can refer to both a station device and an access point device.

[0019] The base station device and the terminal device in the BSS communicate based on CSMA / CA (Carrier sense multiple access with collision avoidance). In this embodiment, the infrastructure mode in which the base station device communicates with a plurality of terminal devices is the subject, but the method of this embodiment can also be implemented in the ad-hoc mode in which the terminal devices directly communicate with each other. In the ad-hoc mode, the terminal device forms a BSS in place of the base station device. The BSS in the ad-hoc mode is also referred to as an IBSS (Independent Basic Service Set). In the following, the terminal device forming the IBSS in the ad-hoc mode can also be considered as a base station device. The method of this embodiment can also be implemented in Wi-Fi Direct (registered trademark) in which the terminal devices directly communicate with each other. In Wi-Fi Direct, the terminal device forms a Group in place of the base station device. In the following, the terminal device of the Group owner that forms a Group in Wi-Fi Direct can also be considered as a base station device.

[0020] In the IEEE 802.11 system, each device can transmit multiple frame types (communication frames) with a common frame format. The frames are defined in the physical (PHY) layer, medium access control (MAC) layer, and logical link control (LLC) layer.

[0021] The transmission frame of the PHY layer is called a physical protocol data unit (PPDU, PHY protocol data unit, physical layer frame). PPDU is composed of a physical layer header (PHY header) that contains header information for signal processing in the physical layer, and a physical service data unit (PSDU, PHY service data unit, MAC layer frame), which is a data unit processed in the physical layer. PSDU can be composed of an aggregated MPDU (A-MPDU), which aggregates multiple MAC protocol data units (MPDUs), which are the retransmission units in the wireless section.

[0022] The PHY header includes reference signals such as a short training field (STF) used for signal detection and synchronization, a long training field (LTF) used to acquire channel information for data demodulation, and control signals such as a signal (SIG) containing control information for data demodulation. STFs are classified into Legacy-STF (L-STF), High Throughput-STF (HT-STF), Very High Throughput-STF (VHT-STF), High Eficiency-STF (HE-STF), Extremely High Throughput-STF (EHT-STF), etc. according to the corresponding standard, and LTFs and SIGs are similarly classified into L-LTF, HT-LTF, VHT-LTF, HE-LTF, L-SIG, HT-SIG, VHT-SIG, HE-SIG, and EHT-SIG. VHT-SIG is further classified into VHT-SIG-A1, VHT-SIG-A2, and VHT-SIG-B. Similarly, HE-SIG is classified into HE-SIG-A1 to HE-SIG-A4 and HE-SIG-B. In addition, it can include a Universal SIGNAL (U-SIG) field that contains additional control information in anticipation of technical updates in the same standard.

[0023] Furthermore, the PHY header can include information for identifying the BSS that is the source of the frame (hereinafter, also referred to as BSS identification information). The information for identifying the BSS can be, for example, the SSID (Service Set Identifier) ​​of the BSS or the MAC address of the base station device of the BSS. The information for identifying the BSS can also be a value unique to the BSS (for example, BSS Color, etc.) other than the SSID or MAC address.

[0024] The PPDU is modulated according to the corresponding standard, for example, into an Orthogonal Frequency Division Multiplexing (OFDM) signal in the IEEE 802.11n standard.

[0025] An MPDU is composed of a MAC header that contains header information for signal processing at the MAC layer, a MAC service data unit (MSDU) or frame body that is a data unit processed at the MAC layer, and a frame check sequence (FCS) that checks whether there are any errors in the frame (Figure 8). In addition, multiple MSDUs can be aggregated as an aggregated MSDU (A-MSDU).

[0026] The frame types of MAC layer frames are broadly classified into three types: management frames that manage the connection status between devices, control frames that manage the communication status between devices, and data frames that contain actual transmission data. Each type is further classified into multiple subframe types. Control frames include acknowledgement (Ack or ACK) frames, request to send (RTS) frames, and clear to send (CTS) frames. Management frames include beacon frames, probe request frames, probe response frames, authentication frames, association request frames, and association response frames. Data frames include data frames and polling (CF-poll) frames. Each device can determine the frame type and subframe type of a received frame by reading the contents of the frame control field included in the MAC header.

[0027] The Ack may include a Block Ack (BA: Block Acknowledgement), which is capable of notifying completion of reception of multiple MPDUs.

[0028] The beacon frame includes a field that describes the period (Beacon interval) at which the beacon is transmitted and the SSID. The base station device can periodically broadcast the beacon frame within the BSS, and the terminal device can identify the base station devices around the terminal device by receiving the beacon frame. The terminal device's identification of the base station device based on the beacon frame broadcast by the base station device is called passive scanning. On the other hand, the terminal device's search for the base station device by broadcasting a probe request frame within the BSS is called active scanning. The base station device can transmit a probe response frame in response to the probe request frame, and the contents of the probe response frame are equivalent to those of the beacon frame.

[0029] After recognizing a base station device, the terminal device performs a connection process with the base station device. The connection process is classified into an authentication procedure and an association procedure. The terminal device transmits an authentication frame (authentication request) to the base station device to which it wishes to connect. When the base station device receives the authentication frame, it transmits an authentication frame (authentication response) to the terminal device that includes a status code indicating whether the terminal device has been authenticated or not. By reading the status code written in the authentication frame, the terminal device can determine whether its own authentication request has been approved by the base station device. Note that the base station device and the terminal device can exchange authentication frames multiple times.

[0030] Following the authentication procedure, the terminal device transmits a connection request frame to the base station device to perform a connection procedure. When the base station device receives the connection request frame, it determines whether or not to permit the connection of the terminal device, and transmits a connection response frame to notify the result. The connection response frame contains a status code indicating whether or not the connection process is possible, as well as an association identifier (AID) for identifying the terminal device. The base station device can manage multiple terminal devices by setting different AIDs for each terminal device for which it has issued connection permission.

[0031] After the connection process is completed, the base station device and the terminal device perform actual data transmission. In the IEEE 802.11 system, a distributed coordination function (DCF), a point coordination function (PCF), and their extended functions (enhanced distributed channel access (EDCA), hybrid coordination function (HCF), etc.) are defined. The following describes an example in which a base station device transmits a signal to a terminal device using DCF.

[0032] In DCF, a base station device and a terminal device perform carrier sense (CS) to check the usage status of a wireless channel around the device before communication. For example, when a base station device, which is a transmitting station, receives a signal higher than a predetermined clear channel assessment level (CCA level) on the wireless channel, it postpones the transmission of a frame on the wireless channel. Hereinafter, a state in which a signal of CCA level or higher is detected on the wireless channel is called a busy state, and a state in which a signal of CCA level or higher is not detected is called an idle state. In this way, CS performed by each device based on the power of a signal actually received (received power level) is called physical carrier sense (physical CS). The CCA level is also called a carrier sense level (CS level) or a CCA threshold (CCA threshold: CCAT). When a signal of CCA level or higher is detected, the base station device and the terminal device start an operation of demodulating at least a PHY layer signal.

[0033] The base station device performs carrier sensing during the inter frame space (IFS) period set according to the type of frame to be transmitted, and judges whether the wireless channel is in a busy or idle state. The period during which the base station device performs carrier sensing varies depending on the frame type and subframe type of the frame the base station device is about to transmit. In the IEEE 802.11 system, multiple IFSs with different periods are defined, including the short inter frame space (SIFS: Short IFS) used for frames assigned the highest priority, the polling inter frame space (PCF IFS: PIFS) used for frames with relatively high priority, and the distributed control inter frame space (DCF IFS: DIFS) used for frames with the lowest priority. When transmitting a data frame using DCF, the base station device uses DIFS.

[0034] After waiting for the DIFS period, the base station device waits for a random backoff time to prevent frame collision. In the IEEE 802.11 system, a random backoff time called a contention window (CW) is used. In CSMA / CA, it is assumed that a frame transmitted by a certain transmitting station is received by a receiving station without interference from other transmitting stations. Therefore, if transmitting stations transmit frames at the same timing, the frames collide with each other and the receiving station cannot receive the frames correctly. Therefore, frame collision is avoided by having each transmitting station wait for a randomly set time before starting transmission. When the base station device determines that the wireless channel is in an idle state by carrier sense, it starts counting down the CW, and only when the CW reaches 0 can it acquire the right to transmit and transmit a frame to the terminal device. If the base station device determines that the wireless channel is in a busy state by carrier sense during the CW countdown, it stops the CW countdown. Then, when the radio channel becomes idle again, the base station device waits for the same period as the previous IFS, and then resumes counting down the remaining CW.

[0035] Next, the details of frame reception will be described. A terminal device, which is a receiving station, receives a frame, reads the PHY header of the frame, and demodulates the received frame. The terminal device can then read the MAC header of the demodulated signal to determine whether the frame is addressed to the terminal device itself. The terminal device can also determine the destination of the frame based on information written in the PHY header (for example, a group identification number (GID: Group identifier, Group ID) written in VHT-SIG-A).

[0036] When a terminal device judges that the received frame is addressed to itself and demodulates the frame without error, it must transmit an Ack frame indicating that the frame was received correctly to the base station device, which is the transmitting station. The Ack frame is one of the highest priority frames that is transmitted only by waiting for the SIFS period (without taking a random backoff time). The base station device ends a series of communications when it receives an Ack frame transmitted from the terminal device. If the terminal device does not receive the frame correctly, it does not transmit an Ack. Therefore, if the base station device does not receive an Ack frame from the receiving station (terminal device) for a certain period (SIFS + Ack frame length) after transmitting a frame, it terminates the communication as it has failed. In this way, the end of one communication (also called a burst) in the IEEE 802.11 system is always determined by the presence or absence of an Ack frame, except in special cases such as the transmission of a notification signal such as a beacon frame or the use of fragmentation to divide the transmission data.

[0037] When a terminal device determines that a received frame is not addressed to the terminal device, the terminal device sets a network allocation vector (NAV) based on the length of the frame described in the PHY header or the like. The terminal device does not attempt communication during the period set in the NAV. In other words, the terminal device performs the same operation as when it determines that the wireless channel is busy by the physical CS during the period set in the NAV, so communication control by the NAV is also called virtual carrier sense (virtual CS). In addition to being set based on the information described in the PHY header, the NAV is also set by a request to send (RTS) frame or a clear to send (CTS) frame introduced to solve the hidden terminal problem.

[0038] In contrast to DCF, in which each device performs carrier sensing and autonomously acquires the transmission right, in PCF, a control station called a Point Coordinator (PC) controls the transmission right of each device within the BSS. In general, a base station device becomes the PC and acquires the transmission right for terminal devices within the BSS.

[0039] The communication period by PCF includes a contention free period (CFP) and a contention period (CP). During the CP, communication is performed based on the DCF described above, and during the CFP, the PC controls the transmission right. The base station device, which is the PC, broadcasts a beacon frame in which the CFP period (CFP Max duration) and the like are described in the BSS prior to the communication of the PCF. Note that the PIFS is used for transmitting the beacon frame broadcast at the start of the transmission of the PCF, and it is transmitted without waiting for the CW. The terminal device that receives the beacon frame sets the CFP period described in the beacon frame to the NAV. After that, the terminal device can acquire the transmission right only when it receives a signal (e.g., a data frame including CF-poll) signaling the acquisition of the transmission right transmitted from the PC until the NAV elapses or a signal (e.g., a data frame including CF-end) is received in the BSS reporting the end of the CFP. During the CFP period, no packet collisions occur within the same BSS, so each terminal device does not take the random backoff time used in DCF.

[0040] A wireless medium can be divided into a number of resource units (RUs). FIG. 4 is a schematic diagram showing an example of a division state of a wireless medium. For example, in resource division example 1, a wireless communication device can divide a frequency resource (subcarrier) which is a wireless medium into nine RUs. Similarly, in resource division example 2, a wireless communication device can divide a subcarrier which is a wireless medium into five RUs. Of course, the resource division example shown in FIG. 4 is only one example, and for example, a number of RUs can be configured with different numbers of subcarriers. In addition, the wireless medium divided into RUs can include not only frequency resources but also spatial resources. A wireless communication device (e.g., an AP) can transmit frames to a number of terminal devices (e.g., a number of STAs) simultaneously by placing frames addressed to different terminal devices in each RU. The AP can write information indicating the division state of the wireless medium (resource allocation information) in the PHY header of a frame transmitted by the AP as common control information. Furthermore, the AP can write information indicating the RU in which the frame addressed to each STA is placed (resource unit assignment information) as unique control information in the PHY header of the frame transmitted by the AP itself.

[0041] Furthermore, multiple terminal devices (e.g., multiple STAs) can transmit frames simultaneously by placing frames in the assigned RUs and transmitting them. After receiving a frame (Trigger frame: TF) containing trigger information transmitted from the AP, multiple STAs can transmit frames after waiting for a predetermined period of time. Each STA can grasp the RU assigned to itself based on the information written in the TF. Furthermore, each STA can acquire an RU by random access based on the TF.

[0042] The AP can simultaneously allocate multiple RUs to one STA. The multiple RUs can be configured with consecutive subcarriers or non-consecutive subcarriers. The AP can transmit one frame using the multiple RUs allocated to one STA, and can allocate multiple frames to different RUs for transmission. At least one of the multiple frames can be a frame including common control information for multiple terminal devices that transmit resource allocation information.

[0043] One STA can be assigned multiple RUs by the AP. The STA can transmit one frame using the assigned multiple RUs. Also, the STA can assign multiple frames to different RUs and transmit them using the assigned multiple RUs. The multiple frames can be frames of different frame types.

[0044] An AP can assign multiple AIDs to one STA. An AP can assign RUs to the multiple AIDs assigned to one STA. An AP can transmit different frames to the multiple AIDs assigned to one STA using the assigned RUs. The different frames can be frames of different frame types.

[0045] A single STA can be assigned multiple AIDs by the AP. A single STA can be assigned RUs for each of the multiple assigned AIDs. A single STA recognizes that all RUs assigned to the multiple AIDs assigned to the single STA are RUs assigned to the single STA, and can transmit one frame using the multiple assigned RUs. A single STA can also transmit multiple frames using the multiple assigned RUs. At this time, the STA can transmit the multiple frames by describing information indicating the AIDs associated with the assigned RUs. The AP can transmit different frames for the multiple AIDs assigned to the single STA using the assigned RUs. The different frames can be frames of different frame types.

[0046] Hereinafter, the base station device and the terminal device are collectively referred to as the wireless communication device or the communication device. In other words, the wireless communication device includes the base station device and the terminal device. In addition, information exchanged when a wireless communication device communicates with another wireless communication device is also referred to as data.

[0047] A wireless communication device has either or both of a function for transmitting a PPDU and a function for receiving a PPDU. FIG. 1 is a diagram showing an example of a PPDU structure transmitted by a wireless communication device. A PPDU conforming to the IEEE 802.11a / b / g standard is configured to include an L-STF, an L-LTF, an L-SIG, and a Data frame (MAC Frame, a MAC frame, a payload, a data section, data, information bits, etc.). A PPDU conforming to the IEEE 802.11n standard is configured to include an L-STF, an L-LTF, an L-SIG, an HT-SIG, an HT-STF, an HT-LTF, and a Data frame. A PPDU conforming to the IEEE 802.11ac standard is configured to include an L-STF, an L-LTF, an L-SIG, a VHT-SIG-A, a VHT-STF, a VHT-LTF, a VHT-SIG-B, and a part or all of a Data frame. The PPDU considered in the IEEE 802.11ax standard is a configuration that includes some or all of the following: L-STF, L-LTF, L-SIG, RL-SIG in which L-SIG is repeated over time, HE-SIG-A, HE-STF, HE-LTF, HE-SIG-B, and Data frames. The PPDU considered in the IEEE 802.11be standard is a configuration that includes some or all of the following: L-STF, L-LTF, L-SIG, RL-SIG, U-SIG, EHT-SIG, EHT-STF, HET-LTF, and Data frames.

[0048] The L-STF, L-LTF, and L-SIG enclosed by dotted lines in Fig. 1 are structures commonly used in the IEEE 802.11 standard (hereinafter, L-STF, L-LTF, and L-SIG are also collectively referred to as L-header). For example, a wireless communication device compatible with the IEEE 802.11a / b / g standard can properly receive an L-header in a PPDU compatible with the IEEE 802.11n / ac standard. A wireless communication device compatible with the IEEE 802.11a / b / g standard can receive a PPDU compatible with the IEEE 802.11n / ac standard by regarding it as a PPDU compatible with the IEEE 802.11a / b / g standard.

[0049] However, wireless communication devices that comply with the IEEE 802.11a / b / g standards cannot demodulate the PPDU that complies with the IEEE 802.11n / ac standards that follows the L-header, and therefore cannot demodulate information related to the transmitter address (TA: Transmitter Address), receiver address (RA: Receiver Address), and the Duration / ID field used to set the NAV.

[0050] IEEE 802.11 specifies a method of inserting Duration information into L-SIG as a method for wireless communication devices conforming to the IEEE 802.11a / b / g standards to appropriately set NAV (or to perform reception for a predetermined period of time). Information on the transmission rate in the L-SIG (RATE field, L-RATE field, L-RATE, L_DATARATE, L_DATARATE field) and information on the transmission period (LENGTH field, L-LENGTH field, L-LENGTH) are used by wireless communication devices conforming to the IEEE 802.11a / b / g standards to appropriately set NAV.

[0051] FIG. 2 is a diagram showing an example of a method of inserting Duration information into an L-SIG. In FIG. 2, a PPDU configuration corresponding to the IEEE 802.11ac standard is shown as an example, but the PPDU configuration is not limited to this. A PPDU configuration corresponding to the IEEE 802.11n standard or a PPDU configuration corresponding to the IEEE 802.11ax standard may also be used. TXTIME includes information on the length of the PPDU, aPreambleLength includes information on the length of the preamble (L-STF+L-LTF), and aPLCPHeaderLength includes information on the length of the PLCP header (L-SIG). L_LENGTH includes a Signal Extension, which is a virtual period set to achieve compatibility with the IEEE 802.11 standard, and an N related to L_RATE. opsIt is calculated based on aSymbolLength, which is information about the duration of one symbol (symbol, OFDM symbol, etc.), aPLCPServiceLength, which indicates the number of bits included in the PLCP Service field, and aPLCPConvolutionalTailLength, which indicates the number of tail bits of the convolutional code. The wireless communication device can calculate L_LENGTH and insert it into the L-SIG. The wireless communication device can also calculate L-SIG Duration. The L-SIG Duration indicates information about the duration obtained by adding up the duration of the PPDU including L_LENGTH and the duration of the Ack and SIFS that are expected to be transmitted from the destination wireless communication device in response to the PPDU.

[0052] FIG. 3 is a diagram showing an example of L-SIG Duration in L-SIG TXOP Protection. DATA (frame, payload, data, etc.) is composed of a MAC frame and a part of a PHY header or both. BA is Block Ack or Ack. PPDU includes L-STF, L-LTF, and L-SIG, and can further include any one or more of DATA, BA, RTS, and CTS. In the example shown in FIG. 3, L-SIG TXOP Protection using RTS / CTS is shown, but CTS-to-Self may also be used. Here, MAC Duration is a period indicated by the value of the Duration / ID field. In addition, the Initiator can transmit a CF-End frame to notify the end of the L-SIG TXOP Protection period.

[0053] Next, a method for identifying a BSS from a frame received by a wireless communication device will be described. In order for a wireless communication device to identify a BSS from a frame received, it is preferable for the wireless communication device transmitting a PPDU to insert information for identifying the BSS (BSS color, BSS identification information, a value unique to the BSS) into the PPDU. Information indicating the BSS color can be described in HE-SIG-A.

[0054] The wireless communication device can transmit the L-SIG multiple times (L-SIG Repetition). For example, the receiving wireless communication device receives the L-SIG transmitted multiple times using MRC (Maximum Ratio Combining), thereby improving the demodulation accuracy of the L-SIG. Furthermore, when the wireless communication device has correctly received the L-SIG using MRC, the wireless communication device can interpret that the PPDU including the L-SIG is a PPDU that complies with the IEEE 802.11ax standard.

[0055] The wireless communication device can receive a part of a PPDU other than the PPDU (for example, a preamble, L-STF, L-LTF, PHY header, etc., defined by IEEE 802.11) even during a PPDU reception operation (also referred to as a dual reception operation). When the wireless communication device detects a part of a PPDU other than the PPDU during a PPDU reception operation, the wireless communication device can update a part or all of the information related to the destination address, the source address, the PPDU, or the DATA period.

[0056] Ack and BA can also be called responses (response frames). In addition, a probe response, an authentication response, and a connection response can also be called responses. [1. First embodiment]

[0057] FIG. 5 is a diagram showing an example of a wireless communication system according to the present embodiment. The wireless communication system 3-1 includes a communication device 1-1 and communication devices 2-1 to 2-3. The communication device 1-1 is also referred to as a base station device 1-1, and the communication devices 2-1 to 2-3 are also referred to as terminal devices 2-1 to 3. The communication devices 2-1 to 2-3 (terminal devices 2-1 to 2-3) are also referred to as a communication device 2A (terminal device 2A) as a device connected to the communication device 1-1. The communication device 1-1 and the communication device 2A are wirelessly connected, and are in a state in which they can transmit and receive PPDUs to each other. The wireless communication system according to the present embodiment may include a wireless communication system 3-2 in addition to the wireless communication system 3-1. The wireless communication system 3-2 includes a communication device 1-2 and communication devices 2-4 to 6. The communication device 1-2 is also referred to as a base station device 1-2, and the communication devices 2-4 to 6 are also referred to as terminal devices 2-4 to 6. Furthermore, the communication devices 2-4 to 6 (terminal devices 2-4 to 6) are also referred to as communication device 2B (terminal device 2B) as devices connected to the communication device 1-2. The wireless communication system 3-1 and the wireless communication system 3-2 form different BSSs, but this does not necessarily mean that the ESSs (Extended Service Sets) are different. An ESS indicates a service set forming a LAN (Local Area Network). In other words, wireless communication devices belonging to the same ESS can be considered to belong to the same network from a higher layer. The BSSs are coupled via a DS (Distribution System) to form an ESS. Each of the wireless communication systems 3-1 and 3-2 can further include a plurality of wireless communication devices.

[0058] In the following description of FIG. 5, it is assumed that a signal transmitted by communication device 2A reaches communication device 1-1 and communication device 2B, but does not reach communication device 1-2. In other words, when communication device 2A transmits a signal using a certain channel, communication device 1-1 and communication device 2B determine that channel to be busy, while communication device 1-2 determines that channel to be idle. Also, it is assumed that a signal transmitted by communication device 2B reaches communication device 1-2 and communication device 2A, but does not reach communication device 1-1. In other words, when communication device 2B transmits a signal using a certain channel, communication device 1-2 and communication device 2A determine that channel to be busy, while communication device 1-1 determines that channel to be idle.

[0059] A multi-link device (MLD) is a device capable of multi-link communication, and an access point device that supports MLD is called an MLD access point device, and a station device that supports MLD is called an MLD station device. Also, MLD access point devices and MLD station devices are collectively called MLD wireless communication devices. In this embodiment, the above-mentioned communication devices 1-1, 1-2, 2A, and 2B are described as MLD wireless communication devices, but in actual operation, all wireless communication devices in a wireless communication system do not necessarily support MLD.

[0060] The MLD access point device 20000-1 and the MLD station device 30000-1 will be described with reference to Fig. 9. The MLD wireless communication device is composed of a plurality of sub-wireless communication devices corresponding to the frequency bands (or channels, or sub-channels) of each link (also called physical layer link) constituting the multi-link. Fig. 9 shows an example in which the MLD access point device 20000-1 is composed of three sub-wireless communication devices, in this case three sub-access point devices (20000-2, 20000-3, 20000-4), but the number of sub-access point devices is any number equal to or greater than two. Similarly, Fig. 9 shows an example in which the MLD station device 30000-1 is composed of three sub-wireless communication devices, in this case three substation devices (30000-2, 30000-3, 30000-4), but the number of substation devices is any number equal to or greater than two. The sub-wireless communication device (sub-access point device, sub-station device, etc.) may be configured as a part of the circuitry within the wireless communication device, and may be called a sub-wireless communication unit (sub-access point unit, sub-station unit).

[0061] 9 shows an example in which a plurality of sub-wireless communication devices are logically configured as separate blocks, but may be physically configured as one wireless communication device. Alternatively, a plurality of sub-wireless communication devices may be configured as physically separate devices, in which case each sub-access point device transmits and receives necessary information via connections 9-1 and 9-2, and each substation device transmits and receives necessary information via connections 9-3 and 9-4. In this embodiment, the former case is mainly used, that is, the device is physically configured as one wireless communication device (10000-1), and the configuration will be described later with reference to FIG. 6 and FIG. 7.

[0062] The number of sub-access point devices included in one MLD access point device and the number of substation devices included in one MLD station device may vary depending on the grade, class, capability, etc. of each MLD wireless communication device. The higher the grade, class, and capability of an MLD wireless communication device, the greater the number of sub-wireless communication devices (sub-access point devices, substation devices) it may have. In other words, the sub-wireless communication devices (sub-access point devices, substation devices) that make up each MLD wireless communication device located in one wireless communication system vary depending on the grade, class, and capability, and the numbers do not have to be the same.

[0063] The substation device 30000-2 connects (associates) with the sub-access point device 20000-2 and establishes link 1. The substation device 30000-3 connects (associates) with the sub-access point device 20000-3 and establishes link 2. The substation device 30000-4 connects (associates) with the sub-access point device 20000-4 and establishes link 3. In the description of this embodiment, the number of links constituting the multi-link is three, but this is not limited to this and may be any number. In the description of this embodiment, the carrier frequency of link 1 is 2.4 GHz band, the carrier frequency of link 2 is 5 GHz band, and the carrier frequency of link 3 is 6 GHz band. However, the frequency band used by each link can be arbitrarily set from frequency bands, channels, and sub-channels supported by the wireless communication system, such as 2.4 GHz band, 5 GHz band, 6 GHz band, and 60 GHz band, and may change according to the laws and regulations of each country.

[0064] 6 is a diagram showing an example of the device configuration of wireless communication device 10000-1. Wireless communication device 10000-1 includes upper layer processing unit (upper layer processing step) 10001-1, autonomous distributed control unit (autonomous distributed control step) 10002-1, transmission unit (transmission step) 10003-1, reception unit (reception step) 10004-1, and antenna unit 10005-1.

[0065] The upper layer processing unit 10001-1 processes information in layers higher than the physical layer, such as the MAC layer and LLC layer, for information handled within the wireless communication device itself (information related to frames to be transmitted, MIB (Management Information Base), etc.) and frames received from other wireless communication devices. The multilink control unit 10001a-1 may be included in the upper layer processing unit 10001-1, or may be independent.

[0066] The upper layer processing unit 10001-1 can notify the autonomous distributed control unit 10002-1 of information related to frames and traffic being transmitted to a wireless medium. The information may be, for example, control information included in a management frame such as a beacon, or measurement information reported by another wireless communication device to the wireless communication device itself. Furthermore, the information may be control information included in a management frame or a control frame without limiting the destination (it may be addressed to the device itself, may be addressed to another device, or may be broadcast or multicast).

[0067] 7 is a diagram showing an example of the device configuration of the autonomous distributed control unit 10002-1. The control unit 10002-1 includes a CCA unit (CCA step) 10002a-1, a backoff unit (backoff step) 10002b-1, a transmission decision unit (transmission decision step) 10002c-1, and a reception decision unit (reception decision step) 10002d-1.

[0068] The CCA unit 10002a-1 can use either or both of information on the power of a signal received via a wireless resource and information on the received signal (including information after decoding) notified from the receiving unit 10004-1 to perform a state determination of the wireless resource (including a determination of whether the wireless resource is busy or idle). The CCA unit 10002a-1 can notify the backoff unit 10002b-1 and the transmission determination unit 10002c-1 of the state determination information of the wireless resource.

[0069] The backoff unit 10002b-1 can perform backoff using wireless resource state determination information. The backoff unit 10002b-1 generates a CW and has a countdown function. For example, when the wireless resource state determination information indicates idle, the backoff unit 10002b-1 can execute a CW countdown, and when the wireless resource state determination information indicates busy, the backoff unit 10002b-1 can stop the CW countdown. The backoff unit 10002b-1 can notify the transmission determination unit 10002c-1 of the CW value.

[0070] The transmission decision unit 10002c-1 makes a transmission decision using either or both of the wireless resource status decision information and the CW value. For example, when the wireless resource status decision information indicates "idle" and the CW value is 0, the transmission decision unit 10003-1 can be notified of the transmission decision information. Also, when the wireless resource status decision information indicates "idle," the transmission decision unit 10003-1 can be notified of the transmission decision information.

[0071] The transmitting unit 10003-1 includes a physical layer frame generating unit (physical layer frame generating step) 10003a-1 and a wireless transmitting unit (wireless transmitting step) 10003b-1. The physical layer frame generating unit 10003a-1 has a function of generating a physical layer frame (PPDU) based on transmission decision information notified from the transmission decision unit 10002c-1. The physical layer frame generating unit 10003a-1 performs error correction coding, modulation, precoding filter multiplication, etc. on a frame transmitted from a higher layer. The physical layer frame generating unit 10003a-1 notifies the wireless transmitting unit 10003b-1 of the generated physical layer frame.

[0072] The reception judgment unit 10002d-1 can instruct the reception unit 10004-1 to receive. A station device in a power management mode (sleep mode, power save mode) normally receives management frames such as beacons intermittently. From information contained in a beacon that the reception unit 10004-1 notifies the autonomous distributed control unit 10002-1, it can be determined whether or not the access point device is buffering a frame addressed to the station device itself. If the access point device is buffering a frame addressed to the station device itself, the reception judgment unit 10002d-1 instructs the reception unit 10004-1 to receive.

[0073] The operation of a station device in the Power Management mode will be described in detail. A station device in the Power Management mode usually receives management frames such as beacons intermittently. A beacon contains IEs (Information Elements, also simply called elements or elements) related to various information. One of these, the Traffic Indication Map (TIM) IE, indicates whether or not the access point device is buffering (accumulating, suspending transmission) frames addressed to the station device in the Power Management mode. One example is a case where 16 bits are assigned to a Partial Virtual Bitmap, and each bit indicates whether or not the access point device is buffering frames addressed to each AID (addressed to each station device). If the bit is set, it indicates that the frame is buffered, and if the bit is reset, it indicates that the frame is not buffered. Note that setting the bit to "1" is usually defined as setting, and setting the bit to "0" is defined as reset. Conversely, it may be defined with different values, such as setting the bit to "0" and resetting the bit to "1".

[0074] The Bitmap Control field includes information on the Bitmap Offset. For example, if the Bitmap Offset value is 0, each bit in the Partial Virtual Bitmap field indicates the presence or absence of buffered frames of station devices corresponding to AID1 to AID16, starting from the left. Since the bits corresponding to AID1, AID4, and AID8 are set, this means that the access point device is buffering frames addressed to AID1, AID4, and AID8. If the Bitmap Offset value is "1" (for simplicity, in this explanation, only one byte of offset is given, but depending on the specifications, it may be multiplied by a constant, such as by applying an offset of two bytes. Also, the offset may be indicated in bits), each bit in the Partial Virtual Bitmap field indicates the presence or absence of buffered frames of station devices corresponding to AID9 to AID24, starting from the left. Since the bits corresponding to AID9, AID12, and AID16 are set, this means that the access point device is buffering frames addressed to AID9, AID12, and AID16. In this way, even if the number of bits allocated to the Partial Virtual Bitmap field is limited, by adjusting the Bitmap Offset value, more AIDs can be expressed, that is, more station devices can be notified of the presence or absence of frames buffered in the access point device.

[0075] The physical layer frame generator performs error correction coding on the information bits transferred from the MAC layer, but the unit (coding block length) for performing error correction coding is not limited to any particular one. For example, the physical layer frame generator can divide the information bit sequence transferred from the MAC layer into information bit sequences of a predetermined length, perform error correction coding on each of them, and generate a plurality of coding blocks. When forming the coding blocks, it is also possible to insert dummy bits into the information bit sequence transferred from the MAC layer.

[0076] The frame generated by the physical layer frame generator 10003a-1 includes control information. The control information includes information indicating in which RU (here, RU includes both frequency resources and spatial resources) data addressed to each wireless communication device is allocated. The frame generated by the physical layer frame generator 10003a-1 also includes a trigger frame that instructs the wireless communication device, which is the destination terminal, to transmit a frame. The trigger frame includes information indicating the RU to be used when the wireless communication device instructed to transmit the frame transmits the frame.

[0077] The wireless transmission unit 10003b-1 converts the physical layer frame generated by the physical layer frame generation unit 10003a-1 into a radio frequency (RF) band signal to generate a radio frequency signal. The processing performed by the wireless transmission unit 10003b-1 includes digital-to-analog conversion, filtering, frequency conversion from the baseband band to the RF band, and the like.

[0078] The receiving section 10004-1 includes a wireless receiving section (wireless receiving step) 10004a-1, a signal demodulating section (signal demodulating step) 10004b-1, and a reception quality measuring section (reception quality measuring step) 10004c-1.

[0079] The reception quality measurement unit 10004c-1 generates information about reception quality from the RF band signal received by the antenna unit 10005-1. The information about the signal quality includes a reception power level, a signal to noise ratio (SNR), and the like. The reception unit 10004-1 may notify the autonomous distributed control unit 10002-1 (particularly, the CCA unit 10002a-1) and the upper layer processing unit 10001-1 (particularly, the multi-link control unit 10001a-1) of the information about the reception quality and the information about the received signal. The reception unit 10004-1 may also notify the autonomous distributed control unit 10002-1 and the upper layer processing unit 10001-1 of other information.

[0080] The wireless receiver 10004a-1 has a function of converting an RF signal received by the antenna unit 10005-1 into a baseband signal and generating a physical layer signal (e.g., a physical layer frame). The processing performed by the wireless receiver 10004a-1 includes frequency conversion from the RF band to the baseband, filtering, and analog-to-digital conversion.

[0081] The signal demodulation unit 10004b-1 has a function of demodulating the physical layer signal generated by the wireless receiving unit 10004a-1. The processing performed by the signal demodulation unit 10004b-1 includes channel equalization, demapping, error correction decoding, and the like. The signal demodulation unit 10004b-1 can extract, for example, information contained in the PHY header, information contained in the MAC header, and information contained in the received frame from the physical layer signal. The signal demodulation unit 10004b-1 can notify the extracted information to the upper layer processing unit 10001-1. The signal demodulation unit 10004b-1 can extract any one or all of the information contained in the PHY header, the information contained in the MAC header, and the information contained in the received frame.

[0082] The antenna unit 10005-1 has a function of transmitting the radio frequency signal generated by the radio transmission unit 10003b-1 into a radio space, and also has a function of receiving the radio frequency signal and passing it to the radio reception unit 10004a-1.

[0083] The multi-link control unit 10001a-1 receives information on the reception quality of each link (each frequency band, each channel, each sub-channel) from the reception quality measurement unit 10004c-1, judges the quality of each link, and decides which link to select and use to configure the multi-link. The information on the reception quality includes, but is not limited to, the reception power level and SNR (Signal to Noise Ratio).

[0084] The wireless communication device 10000-1 can cause the wireless communication devices around the wireless communication device to set NAV for only that period by describing information indicating the period during which the wireless communication device uses the wireless medium in the PHY header or MAC header of the frame to be transmitted. For example, the wireless communication device 10000-1 can describe information indicating that period in the Duration / ID field or Length field of the frame to be transmitted. The NAV period set in the wireless communication devices around the wireless communication device is called the TXOP period (or simply TXOP) acquired by the wireless communication device 10000-1. The wireless communication device 10000-1 that has acquired the TXOP is called a TXOP acquirer (TXOP holder). The frame type of the frame transmitted by the wireless communication device 10000-1 to acquire the TXOP is not limited to any particular type, and may be a control frame (for example, an RTS frame or a CTS-to-self frame) or a data frame.

[0085] The wireless communication device 10000-1, which is a TXOP holder, can transmit frames to wireless communication devices other than the wireless communication device itself during the TXOP. When the wireless communication device 10000-1 is a TXOP holder, the wireless communication device 10000-1 can transmit frames to the communication device 2A during the TXOP period. Furthermore, the wireless communication device 10000-1 can instruct the communication device 2A to transmit a frame addressed to the wireless communication device 10000-1 during the TXOP period. The wireless communication device 10000-1 can transmit a trigger frame including information instructing the communication device 2A to transmit a frame addressed to the wireless communication device 10000-1 during the TXOP period.

[0086] The wireless communication device 10000-1 may reserve a TXOP for all communication bands (e.g., Operation bandwidth) over which frames may be transmitted, or may reserve a TXOP for a specific communication band (Band), such as a communication band (e.g., Transmission bandwidth) over which frames will actually be transmitted.

[0087] The wireless communication device that instructs the wireless communication device 10000-1 to transmit a frame during the period of the acquired TXOP is not necessarily limited to the wireless communication device connected to the wireless communication device itself. For example, the wireless communication device can instruct a wireless communication device that is not connected to the wireless communication device itself to transmit a frame in order to cause a wireless communication device in the vicinity of the wireless communication device itself to transmit a management frame such as a Reassociation frame or a control frame such as an RTS / CTS frame.

[0088] In addition, we will also explain TXOP in EDCA, which is a data transmission method different from DCF. The IEEE 802.11e standard is related to EDCA, and specifies TXOP from the viewpoint of QoS (Quality of Service) guarantee for various services such as video transmission and VoIP (Voice over Internet Protocol). Services are roughly classified into four access categories: VO (VOice), VI (VIdeo), BE (Best Effort), and BK (Background). Generally, the order of priority is VO, VI, BE, and BK. Each access category has parameters such as the minimum value of CW, CWmin, the maximum value, AIFS (Arbitration IFS), which is a type of IFS, and TXOP limit, which is the upper limit of transmission opportunities, and the values ​​are set to give a difference in priority. For example, the CWmin, CWmax, and AIFS of VO, which has the highest priority for voice transmission, can be set to relatively small values ​​compared to other access categories, enabling data transmission with priority over other access categories. For example, in a VI where the amount of data transmitted is relatively large for video transmission, by setting the TXOP limit large, it is possible to secure a longer transmission opportunity than in other access categories.In this way, the values ​​of the four parameters for each access category are adjusted to guarantee QoS according to various services.

[0089] In this embodiment, the signal demodulation unit 10004b-1 of the wireless communication device 10000-1 can perform decoding and error detection on the received signal in the physical layer. Here, the decoding includes decoding of the error correction code applied to the received signal. Here, the error detection includes error detection using an error detection code (e.g., a cyclic redundancy check (CRC) code) that is previously added to the received signal, and error detection using an error correction code that originally has an error detection function (e.g., a low-density parity check code (LDPC)). The decoding process in the physical layer can be applied to each coding block.

[0090] The upper layer processing unit 10001-1 transfers the result of decoding the physical layer in the signal demodulation unit 10004b-1 to the MAC layer. The MAC layer restores the MAC layer signal from the transferred result of decoding the physical layer. Then, the MAC layer performs error detection to determine whether the MAC layer signal transmitted by the wireless communication device that is the transmission source of the received frame has been correctly restored.

[0091] FIG. 10 shows an outline of the procedure related to the multilink of this embodiment, using an MLD wireless communication device 1-1 (hereinafter also referred to as an MLD access point device) and an MLD wireless communication device 2-1 (hereinafter also referred to as an MLD station device) as examples of wireless communication devices. In this case, the MLD wireless communication device 2-1 that transmits a multilink establishment request 10-1 is referred to as a multilink initiator, and transmits the multilink establishment request 10-1 to the MLD wireless communication device 1-1. The multilink establishment request may include control information such as the multilink capability information (Capability information) of the wireless communication device itself and information on the multilink operation mode to be established. The multilink establishment request 10-1 may be included in a management frame such as an Association Request frame. The multilink initiator may be the MLD wireless communication device 1-1 instead of the MLD wireless communication device 2-1. The multilink establishment request may be transmitted independently and separately for each link, or may be transmitted for one of the links constituting the multilink.

[0092] The MLD wireless communication device 1-1 that has received the multi-link establishment request transmits a multi-link establishment response to the MLD wireless communication device 2-1. The multi-link establishment response 10-2 may include control information such as multi-link capability information of the wireless communication device itself, establishment status information indicating whether the multi-link establishment has been successful, a multi-link ID used to identify the multi-link, and multi-link operation mode information. The multi-link operation mode information included in the multi-link establishment response may be finally determined based on the multi-link operation mode included in the multi-link establishment request received from the MLD wireless communication device 2-1 and the multi-link operation mode that the MLD wireless communication device 1-1 can provide. The multi-link operation mode information may include information on the frequency band (or channel, or sub-channel) used in the established multi-link communication. If the establishment status information indicates success, a multi-link is established according to the multi-link operation mode information included in the multi-link establishment response. If the establishment status information indicates failure, the multi-link is not established. The multi-link establishment response 10-2 may be included in a management frame such as an Association Response frame.

[0093] The radio frequency band supported by the MLD wireless communication device according to the present embodiment is not limited to any one. For example, the MLD wireless communication device can support microwave bands (first frequency bands) such as 2.4 GHz, 5 GHz, and 6 GHz, and high frequency bands (second frequency bands) such as 60 GHz (millimeter wave) and 300 GHz (terahertz wave). In particular, since the high frequency band has a large propagation loss compared to the microwave band, a high antenna gain is required to exchange frames. The MLD wireless communication device according to the present embodiment can support analog beamforming based on the control of a phase shifter or the like, digital beamforming based on the control of the phase and amplitude of a digital signal, and hybrid beamforming that combines analog beamforming and digital beamforming. Hereinafter, when simply referred to as beamforming, it refers to any one of the above three beamforming methods. The MLD wireless communication device according to the present embodiment can be provided with a plurality of sub-wireless communication devices, and for example, the first sub-wireless communication device and the second sub-wireless communication device can each support beamforming. Moreover, the beamforming according to the present embodiment includes changing the antenna pattern used when transmitting a frame, and also includes changing the antenna pattern used when receiving a frame.

[0094] In this embodiment, the method of distinguishing the antenna patterns is not limited to anything. For example, when the wireless communication device according to this embodiment can use a plurality of antenna patterns, the antenna patterns can be distinguished based on the width (half width) of the main lobe of each antenna pattern. In addition, the wireless communication device according to this embodiment can set an identifier (beam ID, sector ID) for each of the plurality of antenna patterns. It is preferable that the wireless communication devices that exchange frames share the number of beam IDs that can be set by each of them, the width of the main lobe of the antenna pattern specified by each beam ID, and the direction of the main lobe. For example, the wireless communication devices according to this embodiment can share a beam ID that specifies the antenna pattern with the widest main lobe width among the antenna patterns that can be set by each of them. In addition, the wireless communication devices according to this embodiment can share a beam ID that specifies the antenna pattern with the narrowest main lobe width among the antenna patterns that can be set by each of them.

[0095] As explained above, beamforming support is essential to efficiently perform frame exchange in high frequency bands. However, to perform highly accurate beamforming, high quality is required for hardware such as antennas and phase shifters, and signal processing is also complex. The higher the frequency used in the high frequency band, the greater the gain required for beamforming, which means that the half-width of the main lobe formed by beamforming becomes narrower, and it takes a lot of time to scan the beam in the appropriate direction (beam sweeping). The time required for beam sweeping becomes overhead, and the frequency utilization efficiency decreases.

[0096] Therefore, the wireless communication device according to the present embodiment has a communication method for efficiently exchanging frames in a high frequency band by utilizing the sub wireless communication device that each device has. Specifically, the access point device and the station device included in the same BSS can transmit a response frame to a frame transmitted in a high frequency band using a frequency band other than the high frequency band. By being controlled in this way, for example, when transmitting a frame from the access point device to the station device, the station device only needs to have a function for receiving frames in the high frequency band. Since the station device does not need to have a function for transmitting a response frame in the high frequency band (or does not need to always implement a communication method for transmitting a response frame), it is possible to significantly reduce the cost related to the station device or reduce resources for transmitting a response frame.

[0097] In the wireless communication device according to this embodiment, the first sub wireless communication device and the second sub wireless communication device can exchange frames in different frequency bands. For example, the first sub wireless communication device (first sub access point device, first substation device) supports a first link that communicates in a high frequency band (first frequency band), and the second sub wireless communication device (second sub access point device, second station device) supports a second link that communicates in a microwave band (second frequency band).

[0098] FIG. 11 is a schematic diagram showing an example of communication according to this embodiment. In the example of FIG. 11, a case is described in which an access point apparatus including a first sub-access point apparatus 20000-2 and a second sub-access point apparatus 20000-3 and a station apparatus including a first sub-station apparatus 30000-2 and a second sub-station apparatus 30000-3 exchange frames. The first sub-access point apparatus 20000-2 and the first sub-station apparatus 30000-2 are connected using a first link 11-10. The second sub-access point apparatus 20000-3 and the second sub-station apparatus 30000-3 are connected using a second link 11-11. The first link and the second link are set to different frequency bands. In the following, a case is described in which a high frequency band is set in the first link and a microwave band is set in the second link, that is, a frequency band including a lower frequency than the first link is set in the second link.

[0099] The transmitter of the first sub-access point device transmits a first frame 11-1 in the first link. The first frame is a frame that causes the wireless communication device that receives the first frame to transmit a response frame. Here, the response frame is not limited to anything, but can be, for example, a response confirmation frame (Ack frame) indicating that the first frame has been correctly received, a medium securing response frame (CTS frame) to a medium securing request frame (RTS frame), or a trigger reference data frame (TB PPDU frame) to a trigger frame. The second sub-access point device according to this embodiment performs carrier sense to secure a wireless medium in the second link before the first sub-access point device transmits the first frame in the first link, and secures a wireless medium for a time period 11-20. The time period 11-20 is sufficient to secure a time required for transmitting the response frame 11-2, and may also be secured to secure a time for the second sub-station device or another station device to transmit another frame following the transmission of the response frame 11-2. Also, the second sub-access point may secure the time interval 11-20 by performing carrier sense on the second link after transmitting the first frame 11-1, instead of securing the time interval 11-20 before transmitting the first frame 11-1. In this case, the time interval 11-20 may be secured from the time when the carrier sense is performed until the second substation device can finish transmitting the response frame 11-2.

[0100] It is preferable that the difference between the transmission start timing of the first frame and the start time of the time interval 11-20 is within a predetermined time, and in particular, it is preferable that the start time of the time interval 11-20 precedes the transmission start timing of the first frame. The predetermined time can be set in real time, or can be set by a number of predetermined unit times such as an OFDM signal unit, a time slot unit, or a frame unit. Moreover, the predetermined time can be set for each link supported by the wireless communication device.

[0101] The receiving unit of the first substation device receives the first frame on the first link. The second substation device transmits a response frame 11-2 caused by the first frame on the second link in the time interval 11-20 in which the second sub-access point device has secured the wireless medium by carrier sense. The second substation device may transmit the response frame 11-2 assuming that the time interval 11-20 has been secured when the first substation device has successfully received the first frame. The second sub-access point device may also transmit a control frame to the second substation device to explicitly notify that the time interval 11-20 has been secured. This control frame may be of various formats, and may be, for example, a control frame capable of setting NAV, such as an RTS frame, a PS-Poll frame, or a trigger frame. An example of a series of procedures will be described with reference to FIG. 12. The numbers used in FIG. 12 have the same meaning as those used in FIG. 11, and a control frame 11-3 is added. Before the first sub-access point device transmits the first frame 11-1, the second sub-access point device performs carrier sensing, and if the carrier sensing is successful, transmits a trigger frame that gives the second sub-station device a transmission right as a control packet 11-3. A duration equivalent to the time period 11-20 is set as the NAV of this trigger frame. After the control packet 11-3 is transmitted, the first sub-station device transmits the first frame 11-1 to the first sub-station device. After the first sub-station device successfully receives the first frame 11-1, the second sub-station device transmits a response frame 11-2 within the range of the time period 11-20.

[0102] Next, an example of a procedure for reserving a time interval after the first sub-access point device transmits the first frame will be described with reference to FIG. 13. The numbers used in FIG. 13 are the same as those in FIG. 11, and the differences are the time interval 11-21 used for transmitting the response frame 11-2 to the first frame 11-1 and the control frame 11-4 used for reserving the time interval 11-21. In this example, a BAR (Block Ack Request) frame is used as the control frame 11-4 used for reserving the time interval 11-21. The first sub-access point device transmits the first frame to the first substation device. After transmitting the first frame, the second sub-access point device performs carrier sense, and after the carrier sense is successful, transmits a BAR frame 11-4 to the second substation device, requesting transmission of a block Ack corresponding to the first frame 11-1. The NAV set in this BAR frame is a section equivalent to the time interval 11-21 set for transmitting the response frame 11-2. The second substation apparatus, which has received the BAR frame 11-4, transmits a response frame 11-2 to the second sub-access point apparatus within the range of the time interval 11-21.

[0103] The second sub-access point device may not perform carrier sensing on the second link when transmitting the response frame. The access point device may include, in the first frame, information indicating whether or not to perform carrier sensing on the second link when transmitting the response frame.

[0104] The station device according to the present embodiment can transmit a response frame to the first frame transmitted through the first link through the second link. This indicates that the first substation device supporting the first link only needs to have a function for receiving frames through the first link. Therefore, the first substation device does not necessarily need to have a beamforming function for transmitting frames, but only needs to have a beamforming function for receiving frames, which makes it possible to reduce the cost of station devices including the first substation device.

[0105] In addition, the signal transmitted by the wireless communication device according to the present embodiment in the first frame transmitted through the first link can include an error detection code that enables the wireless communication device that receives the first frame to detect whether the first frame has been correctly received. The wireless communication device can include a plurality of error detection codes in the first frame. For example, the wireless communication device can include at least one of a first error detection code that enables error detection in a PHY layer and a second error detection code that enables error detection in a MAC layer in the first frame. The first error detection code and the second error detection code are not limited to any one. For example, the first error detection code includes a case where information encoded by a predetermined method such as a cyclic redundancy check code (CRC code) is included in the first frame. In addition, the first error detection code also includes a method of determining that reception is successful when a predetermined time period of the first frame can be received with a power higher than a predetermined reception power (for example, a CCA level).

[0106] A transmitter of the first sub-access point device can transmit a first frame including a first error detection code on the first link. When the first sub-station device according to the present embodiment receives the first frame including the first error detection code, the second sub-station device can transmit a response frame including an error detection result based on the first error detection code on the second link. At this time, if the second sub-access point device has secured a wireless medium, the second sub-station device can transmit the response frame including the error detection result on the second link without carrier sensing.

[0107] When the transmitting unit of the first sub-access point device includes the first error detection code and the second error detection code in the first frame, the second substation device can transmit a response frame based on the detection result of the first error detection code without waiting for the error detection by the second error detection code. At this time, the signal included in the response frame can be only a PHY layer signal. That is, the wireless communication device according to this embodiment can grasp information indicating whether frame exchange in the high frequency band has been performed correctly or not by exchanging a frame including only a PHY layer signal. By being controlled in this way, the wireless communication device according to this embodiment can grasp whether the cause of the failure in frame transmission in the high frequency band is due to the PHY layer, such as the method of forming an antenna pattern, or due to a timeout due to too many frame aggregations, or which other cause. In particular, since the exchange of signals in the PHY layer can be performed with low delay, the wireless communication device according to this embodiment can quickly implement a countermeasure against errors in the PHY layer, such as quickly re-executing beam sweeping.

[0108] When the second sub-access point device has secured the wireless medium, if the first sub-station device does not successfully receive the first frame, and there is no response frame transmitted from the second sub-station device, the wireless medium may remain secured. In such a case, the second sub-access point device may transmit a control frame to release (reset) the securing of the wireless medium. The type of this control frame is not limited, but a CF-End frame, an Ack frame, or the like may be used as an example. [2. Second embodiment]

[0109] The wireless communication device according to this embodiment can change the transmission power to be set in a response frame generated by a frame received on a first link, based on the link through which the response frame is transmitted.

[0110] A case where an access point apparatus including a first sub-access point apparatus 20000-2 and a second sub-access point apparatus 20000-3 and a station apparatus including a first sub-station apparatus 30000-2 and a second sub-station apparatus 20000-3 exchange frames will be described as an example. The first sub-access point apparatus 20000-2 and the first sub-station apparatus 30000-2 are connected using a first link 11-10. The second sub-access point apparatus 20000-3 and the second sub-station apparatus 30000-3 are connected using a second link 11-11. The first link and the second link are set to different frequency bands.

[0111] The first sub-access point device transmits a first frame causing a response frame using a first link. When the first frame is received at the first sub-station device, the station device transmits the response frame from at least one of the first sub-station device and the second sub-station device. The station device can set a link for transmitting the response frame based on an instruction from an access point device having the first sub-access point device. Also, the station device can set a link for transmitting the response frame based on the capability of the station device.

[0112] The station device according to the present embodiment can set the transmission power to be set in the response frame based on the link for transmitting the response frame. That is, the station device according to the present embodiment can set different transmission power values ​​for the transmission power (first transmission power) set in the response frame by the first substation device included in the station device and the transmission power (second transmission power) set in the response frame by the second substation device included in the station device. The transmission power in the present embodiment can include at least a part or all of the maximum transmission power, the average transmission power, the operating range of the transmission amplifier, and the equivalent isotropically radiated power (EIRP) including the antenna gain. The wireless communication device according to the present embodiment can flexibly change the transmission power set in the response frame, thereby controlling the effect of the response frame on other wireless communication systems and the reception quality of the response frame.

[0113] The transmission power set in the response frame is not limited to any value. For example, when the frequency of the first frequency band set in the first link is higher than the frequency of the second frequency band set in the second link, the second transmission power set in the response frame by the second substation device can be set to a value lower than the first transmission power set in the response frame by the first substation device.

[0114] In addition, the first substation device and the second substation device according to the present embodiment can determine the transmission power to be set in the response frame based on the CCA level set in the substation device. For example, when the CCA level set in the first substation device is set to -82 dBm / 20 MHz, the first substation device can set the transmission power to be set in the response frame to -82 dBm or less. When the first substation device and the second substation device according to the present embodiment transmit the response frame with a transmission power equal to or less than a predetermined value such as the CCA level shown above, the first substation device and the second substation device can also transmit the response frame without performing carrier sense to secure the wireless medium.

[0115] Furthermore, the first substation device and the second substation device according to the present embodiment can determine the transmission power to be set in the response frame based on information set by the BSS in which the substation device is included or the access point device that manages the BSS. For example, the access point device according to the present embodiment can include information associated with the interference power that the substation device can tolerate in the first frame that causes the response frame. In this case, the access point device can set the information associated with the tolerable interference power to the first link and the second link, respectively.

[0116] The station device that receives the first frame can determine the transmission power to be set in the response frame caused by the first frame based on the information associated with the tolerable interference power. For example, if the information associated with the tolerable interference power is an interference power value that the first sub-access point device can tolerate, the first sub-access point device can set the transmission power of the response frame to a value lower than a value obtained by subtracting the reception power of at least a part of the first frame (e.g., the reception power of a PHY header portion) from the information associated with the tolerable interference power.

[0117] In addition, the transmission power set by the first substation device (or the second substation device) in this embodiment when transmitting the response frame can be set to a transmission power different from the transmission power set by the first substation device (or the second substation device) when transmitting a frame (e.g., a data frame) other than the response frame on the first link (or the second link). At this time, information indicating the BSS set by the first substation device (or the second substation device) in this embodiment for the response frame (first BSS color information) can be set to a value different from information indicating the BSS set by the first substation device (or the second substation device) in this embodiment for a frame other than the response frame (second BSS color information). The first BSS color information and the second BSS color information can be set by the access point device. Also, the access point device can set the first BSS color and the second BSS color for each link. By controlling in this way, a wireless communication device belonging to the BSS can determine whether a received frame is the response frame or not. For example, a wireless communication device belonging to the BSS can change the CCA level for the received frame depending on whether the received frame is determined to be the response frame or a frame other than the response frame (including a case in which it cannot determine whether the frame is the response frame or a frame other than the response frame).

[0118] Furthermore, the wireless communication device according to this embodiment can set the transmission power set in the response frame to, for example, a CCA level or lower, and can also control the beamforming set in the response frame in order to minimize the influence on other nearby communication devices. For example, the first substation device according to this embodiment can transmit the response frame using an antenna pattern (second antenna pattern) different from the antenna pattern (first antenna pattern) used when receiving the first frame that causes the response frame from the first sub-access point device.

[0119] When the first substation device according to this embodiment sets the second antenna pattern to an antenna pattern different from the first antenna pattern, the second antenna pattern can use an antenna pattern having a narrower main lobe width than the first antenna pattern. In this case, it is preferable that the main lobe of the second antenna pattern is a part of the main lobe of the first antenna pattern. In addition, when the first substation device can use a plurality of antenna patterns, it is preferable to use an antenna pattern having a smallest main lobe width among the plurality of antenna patterns as the second antenna pattern set when transmitting a response frame. For example, when the first substation device can use an antenna pattern having a relatively large main lobe width (quasi-omni antenna pattern) and an antenna pattern having a small main lobe width (directional antenna pattern), the directional antenna pattern can be used when transmitting a response frame. In addition, the first substation device according to this embodiment can notify the first substation device of the antenna pattern set in the response frame. In addition, the first substation device according to this embodiment can notify the first access point device of the antenna pattern set in the response frame. In this way, the wireless communication device can grasp the current state of beamforming by exchanging information associated with the antenna pattern set in the response frame.

[0120] Furthermore, the wireless communication device according to the present embodiment can set the response time (response time range) of the response frame based on the link that receives the first frame that causes the response frame. Here, the response time indicates a time interval during which the wireless communication device waits in a receiving operation state in anticipation of the response frame being transmitted after completing the transmission of the first frame. For example, when the time interval is defined as 20 us, if the wireless communication device does not start receiving the response frame within 20 us after completing the transmission of the first frame, it determines that the transmission of the first frame has failed. Also, if the reception of the response frame cannot be completed in the time interval, it can determine that the transmission of the first frame has failed. Note that the response time can be set in real time as described above, or can be set by the number of predetermined unit times, such as an OFDM signal unit, a time slot unit, a frame unit, or a time unit (Time Unit: TU) (1024 microseconds) managed by MAC.

[0121] When the first sub-access point device receives a first frame, the station device can transmit a response frame caused by the first frame from at least one of the first substation device and the second substation device, but the response time for the first frame is set to different values ​​for the response time set when transmitting a response frame on the first link (first response time, first response time range) and the response time set when transmitting a response frame on the second link (second response time, second response time range).

[0122] In this embodiment, the times set for the first response time range and the second response time range are not limited to any particular time. For example, if the frequency of the first frequency band used for the first link for which the first response time range is set is higher than the frequency of the second frequency band used for the second link for which the second response time range is set, the second response time range can be set to be longer than the first response time range.

[0123] Here, the second response time range being longer than the first response time range includes a case where a time longer than the first response time range is set as the second response time range as an actual time. Also, when the response time is set by the number of predetermined unit times, the second response time range being longer than the first response time range includes a case where the predetermined unit time set for the second link is longer than the predetermined unit time set for the first link. Also, when the response time is set by the number of predetermined unit times, the second response time range being longer than the first response time range includes a case where the number of predetermined unit times set for the second link is greater than the number of predetermined unit times set for the first link. [3. Third embodiment]

[0124] The BSS according to this embodiment can be configured with multiple access point devices. For example, the BSS according to this embodiment can include a first access point device and a second access point device, and each of the first access point device and the second access point device can include at least one sub-access point device. Note that the number of sub-access point devices included in the first access point device and the second access point device does not necessarily have to be the same.

[0125] A station device belonging to the BSS according to this embodiment can be connected to a first access point device and a second access point device. The station device can be connected to each access point device exclusively or simultaneously. In addition, when the station device includes multiple substation devices, the multiple substation devices can be connected to the first access point device and the sub-access point device included in the second access point device, respectively. For example, the first substation device can be connected to a first sub-access point of the first access point using a first link, while the second substation device can be connected to a second sub-access point of the second access point using a second link.

[0126] When a station device according to the present embodiment receives a first frame that causes a response frame in a first link, the station device can transmit the response frame to an access point device other than the access point device including the sub-access point device that transmitted the first frame, and to any one of the access point devices (or any one of the sub-access point devices included in the access point device) included in the BSS. At this time, the station device can transmit the response frame through a second link other than the first link. Also, the access point device that transmitted the first frame can indicate the destination of the response frame to the station device. For example, the access point device can include information indicating the destination of the response frame in the PHY header of the first frame.

[0127] According to the method described above, the access point device and the station device can exchange frames using a high frequency band with high efficiency. [4. Common to all embodiments]

[0128] The communication device according to the present invention can communicate in a frequency band (frequency spectrum) called an unlicensed band, which does not require permission to use from a country or region, but the available frequency band is not limited to this. The communication device according to the present invention can also be effective in a frequency band called a white band (for example, a frequency band allocated for television broadcasting but unused in some regions) that is not actually used for the purpose of preventing interference between frequencies even though permission to use the band for a specific service is given by a country or region, and in a shared spectrum (shared frequency band) that is expected to be shared by multiple operators.

[0129] The programs that run on the wireless communication device according to the present invention are programs that control the CPU and other components (programs that make a computer function) to realize the functions of the above-described embodiments of the present invention. Information handled by these devices is temporarily stored in the RAM during processing, and then stored in various ROMs and HDDs, and is then read and written by the CPU as necessary. The program is read, modified, and written by the program. The recording medium for storing the program may be any of semiconductor media (e.g., ROM, non-volatile memory card, etc.), optical recording media (e.g., DVD, MO, MD, CD, BD, etc.), magnetic recording media (e.g., magnetic tape, flexible disk, etc.), etc. Furthermore, not only are the functions of the above-mentioned embodiments realized by executing the loaded program, but the functions of the present invention may also be realized by processing in cooperation with an operating system or other application programs, etc., based on instructions from the program.

[0130] In addition, when distributing the program on the market, the program can be stored in a portable recording medium and distributed, or transferred to a server computer connected via a network such as the Internet. In this case, the storage device of the server computer is also included in the present invention. In addition, a part or all of the communication device in the above-mentioned embodiment may be realized as an LSI, which is typically an integrated circuit. Each functional block of the communication device may be individually chipped, or may be integrated into a chip in part or in whole. When each functional block is integrated into an integrated circuit, an integrated circuit control unit that controls them is added. It goes without saying that the present invention also includes a case where a program or setting information is downloaded from a server computer to implement at least a part of the functions of the above-mentioned embodiment.

[0131] In addition, the method of integration is not limited to LSI, but may be realized by a dedicated circuit or a general-purpose processor. Furthermore, if an integrated circuit technology that can replace LSI appears due to the advancement of semiconductor technology, it is also possible to use an integrated circuit based on that technology.

[0132] The present invention is not limited to the above-mentioned embodiment. The wireless communication device of the present invention is not limited to application to a mobile station device, but can be applied to stationary or non-movable electronic devices installed indoors or outdoors, such as AV equipment, kitchen equipment, cleaning and washing machines, air conditioners, office equipment, vending machines, and other household appliances.

[0133] Although an embodiment of the present invention has been described in detail above with reference to the drawings, the specific configuration is not limited to this embodiment, and designs and the like that do not deviate from the gist of the present invention are also included in the scope of the claims. [Industrial Applicability]

[0134] The present invention is suitable for use in an access point device, a station device, and a communication method. [Explanation of symbols]

[0135] 1-1, 1-2 (MLD) access point device 2-1~2-6 (MLD) Station Equipment 3-1, 3-2 Wireless communication system 10000-1 Wireless communication device 10001-1 Upper layer processing unit 10001a-1 Multi-link control unit 10002-1 Control section 10002a-1 CCA Department 10002b-1 Backoff section 10002c-1 Transmission decision unit 10003-1 Transmitter 10003a-1 Physical layer frame generator 10003b-1 Radio transmitter 10004-1 Receiver 10004a-1 Radio receiver 10004b-1 Signal demodulation section 10004c-1 Reception quality measurement unit 10005-1 Antenna section 20000-1 MLD access point device 20000-2, 20000-3, 20000-4 Sub wireless communication devices (sub access point devices) 30000-1 MLD station equipment 30000-2, 30000-3, 30000-4 Sub-wireless communication equipment (substation equipment) 10-1 Multi-link establishment request 10-2 Multilink establishment response 10-4, 10-5, 10-6 Management Frame 12-11, 12-12, 13-11, 13-12, 14-11, 14-12, 14-21, 14-22, 15-11, 15-12, 16-11, 16-12, 16-13, 16-14, 17-11, 17-12, 17-13, 17-14 Frame configuration 14-1, 14-2 frame combination

Claims

1. A station device that connects to an access point device using a first link using a first frequency band and a second link using the same or different second frequency band as the first frequency band, A receiving unit that receives the first frame via the first link, A transmitting unit that transmits a response frame caused by the first frame over the second link in a second frequency band that is the same as or different from the first frequency band that receives the first frame, Equipped with, The transmitting unit transmits the response frame in the first frequency band over the second link, and transmits the response frame in the second frequency band over the second link, with the transmission power being different depending on the case. The first frame includes first information relating to the carrier sense implementation of the second link, When transmitting the response frame over the second link, the transmitting unit determines whether or not to perform carrier sensing based on at least the first information. Station equipment.

2. When the transmitting unit transmits the response frame in the second frequency band over the second link, if the second frequency band includes frequencies lower than the first frequency band, the transmission power is lower than when the response frame is transmitted in the first frequency band over the second link. The station device according to claim 1.

3. The station device according to claim 1, wherein the transmission power of the response frame is less than or equal to the CCA level set in the BSS to which the device belongs.

4. From the access point device, information associated with the interference power that the access point device allows is obtained. The transmit power of the response frame is lower than the allowable transmit power calculated from the information associated with the interference power. The station device according to claim 1.

5. A first response time range when transmitting the response frame over the second link in the first frequency band and a second response time range when transmitting the response frame over the second link in the second frequency band are set, respectively. The setting value for the second response time range is wider than the setting value for the first response time range. The station device according to claim 1.

6. Connected to a BSS which is composed of multiple access point devices, including the aforementioned access point device, The response frame to the first frame transmitted from the access point device is transmitted to at least one of the plurality of access point devices, which is different from the access point device included in the BSS. The station device according to claim 1.

7. An access point device connected to a station device using a first link using a first frequency band and a second link using the same or different second frequency band as the first frequency band, A transmitting unit that transmits a first frame over the first link, The system includes a receiving unit that receives a response frame caused by the first frame on a second link in a second frequency band that is the same as or different from the first frequency band on which the first frame is transmitted, The transmit power set when the response frame is transmitted over the second link in the first frequency band is different from the transmit power set when the response frame is transmitted over the second link in the second frequency band. The first frame includes first information relating to the carrier sense implementation of the second link. Access point device.

8. A communication method for a station device that connects to an access point device using a first link using a first frequency band and a second link using the same or different second frequency band as the first frequency band, The steps include receiving a first frame on the first link, The steps include transmitting a response frame caused by the first frame over the second link in a second frequency band that is the same as or different from the first frequency band in which the first frame is received, Equipped with, The transmission power differs depending on whether the response frame is transmitted over the second link in the first frequency band or in the second frequency band. The first frame includes first information relating to the carrier sense implementation of the second link, When transmitting the response frame over the second link, it is determined whether or not to perform carrier sensing based on at least the first information. Communication method.

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