Wireless communication device and wireless communication method

Abstract

To make it possible to maintain good communication quality of a wireless link in wireless communication.SOLUTION: A station device 4002 includes a timer 5002-1. When receiving a wireless frame 7003 requiring a response and detecting no reception error, the station device transmits an Ack frame 7004, which is a response frame to the wireless frame 7003, followed by a sounding frame 7005 and resets the timer 5002-1. When the timer 5002-1 reaches an expiration state 7104, the station device 4002 transmits a sounding frame 7009 after a carrier sense and a back-off procedure and resets the timer 5002-1.SELECTED DRAWING: Figure 7

Description

[Technical field]

[0001] The present invention relates to a wireless communication device and a wireless 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 (Local Area Network) communication and more efficient frequency utilization. Wireless LAN allows wireless communication using frequency bands (unlicensed bands) that can be used without permission (license) from countries and regions. For personal use such as at home, wireless LAN 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 a line termination device. This allows wireless LAN station devices such as smartphones and personal computers to connect to a wireless LAN access point device and access the Internet.

[0003] In 2021, the IEEE 802.11ax standard will be completed, and wireless LAN devices that comply with this standard, as well as communication devices such as smartphones and personal computers equipped with the wireless LAN devices, will appear on the market as Wi-Fi 6 (registered trademark, the name for IEEE 802.11ax-compliant products certified by the Wi-Fi Alliance). Currently, standardization activities for IEEE 802.11be as 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 is considering further improving throughput per user in environments where wireless LAN devices are densely deployed.

[0004] In addition, in the IEEE 802.11be standardization, there is discussion on Multi-Link Operation (MLO), which enables a wireless communication device to maintain multiple link connections and communicate by simultaneously using multiple frequency bands, channels, etc. (Non-Patent Document 1). One example of MLO is a simultaneous operation of three link connections in different frequency bands, namely, a 2.4 GHz band connection, a 5 GHz band (5.2 GHz band, 5.3 GHz band, 5.6 GHz band, etc.) connection, and a 6 GHz band connection. Of course, the combination of frequency bands, channels, etc. is not limited to this, and various combinations are possible. From the viewpoint of frequency bands, in the future, high frequency bands such as millimeter waves (28 GHz band, 45 GHz band, 60 GHz band, etc.) and (sub) terahertz waves (100 GHz to 300 GHz band) may also be used as one link constituting a multi-link. According to MLO, a wireless communication device can simultaneously maintain multiple link connections with different settings related to the wireless resources and communication used. A wireless communication device can not only transmit and receive frames using multiple links simultaneously, but also switch the link connection for transmitting and receiving frames, i.e., change the frequency band, without performing a reconnection operation. Each link that constitutes a multilink here is also called a physical layer link. A wireless communication device that supports MLO is called a multilink device (MLD). [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] In wireless LAN, maintaining the communication quality of the wireless link is a challenge to achieve high speed and efficient frequency utilization. [Means for solving the problem]

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

[0008] (1) That is, a wireless communication device according to one embodiment of the present invention is a wireless communication device that communicates with a wireless communication device of a communication partner using a wireless link, and includes a wireless communication unit that transmits and receives wireless frames over a first wireless link, and a wireless control unit that has a first timer, wherein the wireless control unit activates the first timer when the wireless communication unit receives a wireless frame including first control information indicating that the first timer is to be set, and when a first wireless frame that requires a response is received over the first wireless link, the wireless communication unit transmits a first response frame to the first wireless frame and then transmits a first sounding frame without carrier sensing, and the wireless control unit resets the first timer, and when the first timer expires, the wireless communication unit transmits the first sounding frame after performing carrier sensing over the first wireless link, and the wireless control unit resets the first timer.

[0009] (2) Furthermore, a wireless communication device according to one embodiment of the present invention is a wireless communication device that communicates with a wireless communication device of a communication partner by simultaneously using multiple wireless links including the first wireless link and a second wireless link having a frequency band different from that of the first wireless link, wherein the wireless communication unit further transmits and receives wireless frames via the second wireless link, and the wireless control unit further includes a second timer, and when the wireless communication unit receives a wireless frame including second control information indicating that the second timer is to be set, the wireless communication unit activates the second timer, and when a second wireless frame that requires a response is received via the second wireless link, the wireless communication unit transmits a second response frame to the second wireless frame and then transmits a second sounding frame without carrier sensing, and the wireless control unit resets the second timer, and when the second timer expires, the wireless communication unit transmits the second sounding frame after performing carrier sensing on the second wireless link, and the wireless control unit resets the second timer.

[0010] (3) In addition, in a wireless communication device according to one embodiment of the present invention, if the first timer has reached a predetermined value when the first wireless frame is received, the wireless communication unit transmits the first sounding frame without carrier sense following transmission of the first response frame.

[0011] (4) In addition, in a wireless communication device according to one embodiment of the present invention, when the first response frame is a block response frame, if the number of positive responses included in the block response frame is less than a predetermined number, the wireless communication unit transmits the first sounding frame without carrier sensing following transmission of the block response frame.

[0012] (5) In addition, in a wireless communication device according to one embodiment of the present invention, the wireless control unit sets an expiration condition for the first timer and resets the first timer when the wireless communication unit receives a wireless frame including third control information.

[0013] (6) Furthermore, in the wireless communication device according to the aspect of the present invention, the third control information is information for setting Quality of Service (QoS).

[0014] (7) In addition, in a wireless communication device according to one embodiment of the present invention, the wireless control unit deactivates the first timer when the wireless communication unit receives a wireless frame including fourth control information.

[0015] (8) Furthermore, in the wireless communication device according to the aspect of the present invention, the fourth control information is information for canceling a QoS setting.

[0016] (9) In addition, in a wireless communication device according to one embodiment of the present invention, the wireless control unit further includes a third timer, and when the wireless communication unit receives a wireless frame including the first control information, the wireless control unit activates the first timer and the third timer. If the third timer has expired when the wireless communication unit receives the first wireless frame, the wireless communication unit transmits the first sounding frame without carrier sensing following the transmission of the first response frame, and the wireless control unit resets the first timer and the third timer. If the first timer has expired, the wireless communication unit transmits the first sounding frame after performing carrier sensing on the first wireless link, and the wireless control unit resets the first timer and the third timer.

[0017] (10) In addition, in a wireless communication device according to one embodiment of the present invention, if the first timer has reached a predetermined value when the first wireless frame is received, the wireless communication unit transmits the first sounding frame without carrier sensing following the transmission of the first response frame, and if the second timer has reached a predetermined value when the second wireless frame is received, the wireless communication unit transmits the second sounding frame without carrier sensing following the transmission of the second response frame.

[0018] (11) In addition, in a wireless communication device according to one embodiment of the present invention, when the first response frame or the second response frame is a block response frame, if the number of positive responses included in the block response frame is less than a predetermined number, the wireless communication unit transmits the first sounding frame or the second sounding frame without carrier sense following transmission of the block response frame.

[0019] (12) In a wireless communication device according to one embodiment of the present invention, the wireless control unit sets an expiration condition for the first timer and resets the first timer when the wireless communication unit receives a wireless frame including third control information, and sets an expiration condition for the second timer and resets the second timer when the wireless communication unit receives a wireless frame including fifth control information.

[0020] (13) In a wireless communication device according to one embodiment of the present invention, the wireless control unit deactivates the first timer when the wireless communication unit receives a wireless frame including fourth control information, and deactivates the second timer when the wireless communication unit receives a wireless frame including sixth control information.

[0021] (14) Furthermore, a wireless communication device according to one embodiment of the present invention is a wireless communication device that communicates with a counterpart wireless communication device using a wireless link, and includes a wireless communication unit that transmits and receives wireless frames over a first wireless link, and a wireless control unit that generates control information, wherein the wireless control unit generates first control information including setting and reset conditions for a first timer included in the counterpart wireless communication device and transmission conditions for a sounding frame from the counterpart wireless communication device, and the first wireless communication unit transmits a wireless frame including the first control information.

[0022] (15) Also, a communication method according to one embodiment of the present invention is a communication method in a wireless communication device that communicates with another wireless communication device using a wireless link, comprising the steps of: receiving a wireless frame including first control information indicating setting a first timer; activating the first timer when the wireless frame including the first control information is received; receiving a first wireless frame that requires a response in the first wireless link; transmitting a first response frame to the first wireless frame; transmitting a first sounding frame without carrier sensing following the transmission of the first response frame and resetting the first timer; and, if the first timer expires, transmitting the first sounding frame after performing carrier sensing in the first wireless link and resetting the first timer. Effect of the Invention

[0023] According to the wireless communication device and wireless communication method of the present invention, it is possible to maintain good communication quality of a wireless link in wireless communication. [Brief description of the drawings]

[0024] [Figure 1] FIG. 2 is a diagram illustrating an example of a MAC layer frame configuration in a wireless LAN system. [Diagram 2] FIG. 2 is a diagram illustrating an example of a PPDU configuration related to a wireless LAN system. [Diagram 3] FIG. 1 is a diagram showing an example of a sounding procedure related to a wireless LAN system. [Figure 4] FIG. 1 is a diagram illustrating an example of a configuration of a communication system according to an aspect of the present invention. [Diagram 5] 1 is a block diagram showing an example of a configuration of a station device according to an aspect of the present invention; [Figure 6] 1 is a block diagram showing an example of a configuration of an access point device according to an aspect of the present invention. [Figure 7]FIG. 2 is a diagram showing an example of a sounding procedure in a wireless communication system according to an embodiment of the present invention. [Figure 8] FIG. 2 is a diagram showing an example of a sounding procedure in a wireless communication system according to an embodiment of the present invention. [Figure 9] FIG. 4 is a flow chart of an example of a sounding procedure in a station device according to an embodiment of the present invention. [Figure 10] FIG. 1 is a diagram illustrating an example of a configuration of a communication system according to an aspect of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0025] The wireless communication system in this embodiment includes an access point device (AP, also referred to as a base station device) and multiple station devices (STA, also referred to as terminal devices). The communication system and network configured with the access point device and the station devices are 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 represent both an access point device and a station device.

[0026] The access point device and station 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 access point device communicates with a plurality of station devices is the subject, but the method of this embodiment can also be implemented in the ad-hoc mode in which the station devices communicate directly with each other. In the ad-hoc mode, one station device acts as an access point device to form a BSS. The BSS in the ad-hoc mode is also referred to as an IBSS (Independent Basic Service Set). In the following, the station device that forms the IBSS in the ad-hoc mode can also be considered as an access point device. The method of this embodiment can also be implemented in Wi-Fi Direct (registered trademark) in which the station devices communicate directly with each other. In Wi-Fi Direct, one station device acts as an access point device to form a group. The station device is called a group owner and can also be considered as an access point device.

[0027] In the IEEE 802.11 system, each device can transmit multiple types of frames (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.

[0028] A frame in the PHY layer is called a Physical Protocol Data Unit (PPDU, PHY Protocol Data Unit, physical layer frame). A PPDU is composed of a physical layer header (PHY header) that contains information for signal processing in the physical layer, and a physical service data unit (PSDU, PHY Service Data Unit), which is a data unit processed in the physical layer. A PSDU can be composed of an aggregated MPDU (A-MPDU, Aggregated MPDU), which is an aggregate of multiple MAC Protocol Data Units (MPDU, MAC layer frames), which are the units of retransmission in the wireless section.

[0029] 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.

[0030] Furthermore, the PHY header can include information for identifying the BSS of 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 access point device of the BSS. The information for identifying the BSS can also be a value unique to the BSS (for example, BSS Color) other than the SSID or MAC address. Information indicating the BSS Color can be included in the HE-SIG-A or U-SIG.

[0031] 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.

[0032] An MPDU is composed of a MAC header that contains information for signal processing in the MAC layer, a MAC Service Data Unit (MSDU) or frame body that is a data unit processed in the MAC layer, and a Frame Check Sequence (FCS) that checks whether there are any errors in the frame (Figure 1). In addition, multiple MSDUs can be aggregated as an Aggregated MSDU (A-MSDU).

[0033] Frame types in the MAC layer 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, block acknowledgement (BA or BlockAck) frames, request to send (RTS) frames, and clear to send (CTS) frames. BlockAck can perform acknowledgement (notification of completion of reception) for multiple MPDUs. 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 recognize the frame type and subframe type of a received frame by reading the contents of the frame control field included in the MAC header.

[0034] The beacon frame includes a field indicating the period (Beacon interval) at which the beacon is transmitted and the SSID. The access point device can periodically broadcast the beacon frame within the BSS, and the station device can recognize the surrounding access point device by receiving the beacon frame. The station device's recognition of the access point device based on the beacon frame broadcast by the access point device is called passive scanning. On the other hand, the station device's search for the access point device by broadcasting a probe request frame within the BSS is called active scanning. The access point device can transmit a probe response frame in response to the probe request frame, and the contents of the probe response frame are the same as the contents of the beacon frame.

[0035] After recognizing an access point device, a station device performs a connection process with the access point device. The connection process is classified into an authentication procedure and an association procedure. The station device transmits an authentication request frame to the access point device with which it wishes to connect. When the access point device receives the authentication request frame, it transmits an authentication response frame to the station device, which includes a status code indicating whether the station device has been authenticated. By reading the status code included in the authentication response frame, the station device can determine whether its own device has been granted an authentication request by the access point device. The access point device and station device can exchange authentication request frames and authentication response frames (both of which are collectively referred to as authentication frames) multiple times.

[0036] Following the authentication procedure, the station device transmits a connection request frame to the access point device to perform a connection procedure. When the access point device receives the connection request frame, it determines whether or not to permit the connection of the station device, and transmits a connection response frame to notify the result. The connection response frame contains an association identification number (AID) for identifying the station device, in addition to a status code indicating whether or not the connection process is possible. The access point device can manage multiple station devices by setting different AIDs for each station device that it has issued connection permission to.

[0037] After the connection process is completed, the access point device and the station device perform actual data transmission. In the IEEE 802.11 system, Distributed Coordination Function (DCF), Point Coordination Function (PCF), and their extended Hybrid Coordination Function (HCF) are defined as media access methods. Specific implementation methods for HCF include Enhanced Distributed Channel Access (EDCA) and HCF Controlled Channel Access (HCCA).

[0038] First, an example of the operation when an access point device transmits a signal to a station device based on DCF will be described. In DCF, the access point device and the station device perform carrier sense (CS) to check the usage status of the wireless channel around the device before communication. For example, when the access point device and the station device that are about to transmit a frame receive a signal with a reception power higher than a predetermined clear channel assessment level (CCA level) in the wireless channel during the carrier sense period performed prior to transmission, the access point device and the station device postpone the transmission of the frame in the wireless channel. Hereinafter, a state in which a signal with a reception power equal to or higher than the CCA level is detected in the wireless channel is called a busy state, and a state in which a signal with a reception power equal to or higher than the CCA level is not detected is called an idle state. In this way, the CS performed by each device based on the power level of the signal actually received is called a physical carrier sense (physical CS). The CCA level is also called a carrier sense level (CS level) or a CCA threshold (CCAT). When the access point device and station device detect a signal with a reception power equal to or higher than the CCA level, the access point device and station device start an operation of demodulating at least the signal of the PHY layer.

[0039] The access point 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 busy or idle. The period during which the access point device performs carrier sensing varies depending on the frame type and subframe type of the frame that the access point 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 (PIFS: PCF IFS) used for frames with relatively high priority, and the distributed arbitration inter frame space (DIFS: DCF IFS) used for frames with low priority. When transmitting a data frame using DCF, the access point device uses DIFS.

[0040] After waiting for the DIFS period, the access point device further waits for a random backoff time to prevent frame collision. In the IEEE 802.11 system, a random backoff time based on 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 multiple transmitting stations transmit frames at the same timing, the frames may collide with each other and the receiving station may not be able to 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 access point device determines that the wireless channel is in an idle state by carrier sense, it starts counting down a backoff counter set based on the CW, and only when the backoff counter reaches 0 can it acquire the right to transmit and transmit a frame to the station device. Note that if the access point device determines that the wireless channel is in a busy state by carrier sense during the backoff counter countdown, it stops counting down the backoff counter. Then, when the wireless channel becomes idle again, the access point device waits for the same period as the previous IFS, and then resumes the remaining countdown of the previous backoff counter.

[0041] A station device, which is a receiving station, receives a frame, reads the PHY header of the frame, and demodulates the received frame. The station device can then determine whether the frame is addressed to the station device by reading the MAC header of the demodulated signal. The station device can also determine the destination of the frame based on information included in the PHY header (e.g., a group identification number (GID: Group Identifier, Group ID) included in VHT-SIG-A).

[0042] When a station device determines 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 access point 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 access point device ends a series of communications when it receives the Ack frame transmitted from the station device. If the station device does not receive the frame correctly, the station device does not transmit the Ack frame. Therefore, if the access point device does not receive an Ack frame from the receiving station (station device) within a certain period (SIFS + Ack frame length) after transmitting the frame, it determines that the communication has failed and ends the communication. 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 the 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.

[0043] When a station device determines that a received frame is not addressed to the device itself, the station device sets a network allocation vector (NAV) based on the length of the frame included in the PHY header or the like. The station device does not attempt transmission during the period set in the NAV. In other words, the station 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 information included in the PHY header, the NAV is also set by an RTS frame or a CTS frame introduced to solve the hidden terminal problem.

[0044] Next, an example of the operation when an access point device transmits a signal to a station device based on PCF will be described. Unlike DCF, in which each device performs carrier sense and autonomously acquires the transmission right, in PCF, a control station called a Point Coordinator (PC) controls the transmission right of each device in the BSS. Generally, an access point device becomes a PC and acquires the transmission right of a station device in the BSS.

[0045] 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 access point device, which is the PC, broadcasts a beacon frame including information such as the CFP period (CFP Max duration) in the BSS prior to PCF communication. Note that the beacon frame broadcast at the start of PCF transmission is transmitted using PIFS, without waiting for the CW. The station device that receives the beacon frame sets the CFP Max duration included in the beacon frame in the NAV. After that, the station device can acquire the transmission right only when it receives a signal (e.g., a data frame including CF-poll) from the PC signaling the acquisition of the transmission right for the device until the period set in the NAV has elapsed or a signal (e.g., a data frame including CF-end) that broadcasts the end of the CFP in the BSS is received. During the CFP period, no packet collisions occur within the same BSS, so each station device does not take the random backoff time used in DCF.

[0046] The wireless communication device has either or both of a function for transmitting and receiving a PPDU. Fig. 2 is a diagram showing an example of a PPDU configuration transmitted by a wireless communication device. A PPDU conforming to the IEEE 802.11a / g standard is configured to include an L-STF, an L-LTF, an L-SIG, and a Data frame (MAC frame, payload, 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 a part or all of 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 Data frame. The PPDU conforming to the IEEE 802.11ax standard is configured to include 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 standardization is configured to include 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.

[0047] The L-STF, L-LTF, and L-SIG enclosed by dotted lines in Fig. 2 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 / g standard can properly receive an L-header in a PPDU compatible with the IEEE 802.11n / ac / ax / be standard. A wireless communication device compatible with the IEEE 802.11a / g standard can receive a PPDU compatible with the IEEE 802.11n / ac / ax / be standard as a PPDU compatible with the IEEE 802.11a / g standard.

[0048] However, wireless communication devices that comply with the IEEE 802.11a / g standards cannot demodulate the PPDU that follows the L-header and complies with the IEEE 802.11n / ac / ax / be standards, and therefore cannot demodulate information related to the sender address (TA: Transmitter Address), receiver address (RA: Receiver Address), Duration / ID field, etc.

[0049] 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 / g standard to appropriately set NAV (or to perform reception operation for a predetermined period). 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 / g standard to appropriately set NAV.

[0050] The wireless communication device can transmit the L-SIG multiple times (L-SIG Repetition). In this case, the wireless communication device on the receiving side can improve the demodulation accuracy of the L-SIG by receiving the L-SIG transmitted multiple times using Maximal Ratio Combining (MRC), for example. Furthermore, when the wireless communication device has correctly received the L-SIG using MRC, it can interpret that the PPDU including the L-SIG is a PPDU that complies with the IEEE 802.11ax or IEEE 802.11be standard.

[0051] 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., as 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.

[0052] 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.

[0053] FIG. 3 is a diagram showing an example of a procedure of sounding for channel estimation of a wireless communication path in IEEE 802.11ax. In the example of FIG. 3, an access point device (AP) first transmits a Null Data PPDU (NDP) Announcement frame 3001 that specifies information indicating a station device (STA) that is to be the target of sounding (recipient of a sounding frame) to be performed and a type of feedback information. Furthermore, the access point device transmits an NDP frame 3002 including a training field for channel estimation after a SIFS period from the NDP Announcement frame. The station device performs channel estimation based on the received NDP frame 3002, and transmits a frame, for example, a Compressed Beamforming / CQI frame 3003, for feeding back the channel estimation result to the access point device after a SIFS period from the NDP frame 3002. [1. First embodiment]

[0054] FIG. 4 is a diagram showing an example of a wireless communication system according to this embodiment. Wireless communication system 4003-1 includes wireless communication device 4001-1 and wireless communication devices 4002-1 to 4002-3. Wireless communication device 4001-1 is also referred to as access point device 4001-1, and wireless communication devices 4002-1 to 4002-3 are also referred to as station devices 4002-1 to 3. Wireless communication devices 4002-1 to 4002-3 (station devices 4002-1 to 4002-3) are also referred to as wireless communication device 4002A (station device 4002A) as devices connected to wireless communication device 4001-1. Wireless communication device 4001-1 and wireless communication device 4002A are wirelessly connected, and are in a state where they can transmit and receive PPDU to each other. The wireless communication system according to this embodiment may include wireless communication system 4003-2 in addition to wireless communication system 4003-1. Wireless communication system 4003-2 includes wireless communication device 4001-2 and wireless communication devices 4002-4 to 4002-6. Wireless communication device 4001-2 is also referred to as access point device 4001-2, and wireless communication devices 4002-4 to 4002-6 are also referred to as station devices 4002-4 to 4002-6. Wireless communication devices 4002-4 to 4002-6 (station devices 4002-4 to 4002-6) are also referred to as wireless communication device 4002B (station device 4002B) as devices connected to wireless communication device 4001-2. Furthermore, wireless communication device 4001-1 and wireless communication device 4001-2 (access point device 4001-1, 4001-6) are also referred to as wireless communication device 4001 (access point device 4001) when describing without specifying each of them, and wireless communication devices 4002-1 to 4002-6 (station devices 4002-1 to 4002-6) are also referred to as wireless communication device 4002 (station device 4002) when describing without specifying each of them. Wireless communication system 4003-1 and wireless communication system 4003-2 form different BSSs, but this does not necessarily mean that ESSs (Extended Service Sets) representing service sets forming LANs (Local Area Networks) are different.In other words, wireless communication devices that belong to the same ESS can be regarded as belonging to the same network from a higher layer. Also, BSSs are coupled via a DS (Distribution System) to form an ESS. Each of the wireless communication systems 4003-1 and 4003-2 can further include multiple wireless communication devices.

[0055] 5 is a diagram showing an example of the configuration of station device 4002. Station device 4002 includes a wireless control unit (wireless control step) 5001, a timer unit (timer step) 5002, a wireless communication unit (wireless communication step) 5003, and an antenna unit 5004. Furthermore, wireless communication unit 5003 includes a physical layer frame generation unit (physical layer frame generation step) 5003a, a wireless transmission unit (wireless transmission step) 5003b, a wireless reception unit (wireless reception step) 5003c, a received power measurement unit (received power measurement step) 5003d, a channel estimation unit (channel estimation step) 5003e, and a signal demodulation unit (signal demodulation step) 5003f.

[0056] The wireless control unit 5001 performs information processing on layers higher than the physical layer, such as the MAC layer and LLC layer, for information handled within the wireless communication device itself (such as information related to frames to be transmitted and MIB (Management Information Base)) and frames received from other wireless communication devices, and also controls the wireless communication unit 5003.

[0057] The timer unit 5002 includes one or more timers, and manages timers related to the sounding process. Details of the timer unit 5002 will be described later. Note that, in the example of FIG. 5, the timer unit 5002 is described as being included in the wireless control unit 5001, but is not limited to this configuration, and may be provided outside the wireless control unit 5001 and configured to operate under the control of the wireless control unit 5001.

[0058] The physical layer frame generating unit 5003a has a function of generating a physical layer frame (PPDU). The physical layer frame generating unit 5003a performs error correction coding, modulation, beamforming processing (precoding processing), and the like on the MAC layer frame transmitted from the wireless control unit 5001. The beamforming processing may be realized by multiplying the modulated signal by a beamforming matrix (beamforming filter) notified from the wireless control unit 5001. The physical layer frame generating unit 5003a outputs the generated physical layer frame to the wireless transmission unit 5003b.

[0059] The wireless transmission unit 5003b converts the physical layer frame input from the physical frame generation unit 5003a into a signal in the radio frequency (RF) band to generate a wireless signal. The processing performed by the wireless transmission unit 5003b includes digital-to-analog conversion, filtering, and frequency conversion from a baseband frequency to a wireless frequency. The wireless transmission unit 5003b transmits the generated wireless signal via the antenna unit 5004.

[0060] The wireless receiver 5003c has a function of converting a wireless signal received through the antenna unit 5004 into a baseband signal and generating a physical layer signal (for example, a physical layer frame). The processing performed by the wireless receiver 5003c includes frequency conversion processing from a wireless frequency to a baseband frequency, filtering, analog-to-digital conversion, etc. The physical layer signal, which is the received signal converted into a digital signal by the wireless receiver 5003c, is input to the received power measurement unit 5003b, the channel estimation unit 5003e, and the signal demodulation unit 5003f.

[0061] The received power measuring unit 5003d measures the received power of the received signal input from the wireless receiving unit 5003c. The received power measuring unit 5003d can measure the received power of the radio wave received in the frequency channel to be measured, the received power of the LTF of the received physical layer frame, etc. The received power measuring unit 5003d can notify the wireless control unit 5001 of the measurement result of the received power.

[0062] The channel estimation unit 5003e estimates the channel state through which the physical layer frame has propagated based on a received signal of an LTF (L-LTF, HT-LTF, VHT-LTF, HE-LTF, etc.) included in the physical layer frame received by the wireless receiving unit 5003c. The channel estimation unit 5003e can notify the signal demodulation unit 5003f and the wireless control unit 5001 of the channel estimation result.

[0063] The signal demodulation unit 5003f performs channel equalization, demodulation, error correction decoding, etc. on the physical layer frame received by the wireless receiving unit 5003c, and acquires information such as a PHY header and a MAC layer frame. The channel equalization process can use the channel estimation result from the channel estimation unit 5003e. The signal demodulation unit 5003f outputs the acquired PHY header and MAC layer frame to the wireless control unit 5001.

[0064] The wireless control unit 5001 can perform physical carrier sensing and virtual carrier sensing based on the received power measurement result in the received power measuring unit 5003d and the information acquired in the signal demodulation unit 5003f, and can determine the state of the wireless channel (including determining whether it is in an idle state or a busy state). The wireless control unit 5001 can notify the wireless communication unit 5003 of this wireless channel state determination information.

[0065] When there is control information, data, etc. to be transmitted, the wireless control unit 5001 can start a back-off procedure using the state determination information of the wireless channel. The wireless control unit 5001 generates a back-off counter based on the CW and has a count-down function of the back-off counter. For example, when the state determination information of the wireless channel indicates an idle state, the wireless control unit 5001 can execute count-down of the back-off counter, and when the state determination information of the wireless channel indicates a busy state, the wireless control unit 5001 can stop count-down of the back-off counter. Furthermore, the wireless control unit 5001 makes a transmission decision using either or both of the state determination information of the wireless channel and the value of the back-off counter. For example, when the state determination information of the wireless channel indicates an idle state and the value of the back-off counter is 0, the wireless control unit 5001 can notify the wireless communication unit 5003 of transmission decision information. Furthermore, when the state determination information of the wireless resource indicates an idle state, the wireless control unit 5001 can notify the wireless communication unit 5003 of transmission decision information.

[0066] FIG. 6 is a diagram showing an example of the configuration of the access point device 4001. The access point device 4001 includes a wireless control unit (wireless control step) 6001, a wireless communication unit (wireless communication step) 5003, and an antenna unit 5004. Furthermore, the wireless communication unit 5003 includes a physical layer frame generation unit (physical layer frame generation step) 5003a, a wireless transmission unit (wireless transmission step) 5003b, a wireless reception unit (wireless reception step) 5003c, a received power measurement unit (received power measurement step) 5003d, a channel estimation unit (channel estimation step) 5003e, and a signal demodulation unit (signal demodulation step) 5003f. The access point device 4001 in FIG. 6 is basically configured similarly to the station device 4002 in FIG. 5. Therefore, in the following, the differences between the two will be mainly described, and the description of the similar parts will be omitted. Also, the parts corresponding to the station device in FIG. 5 will be described with the same reference numerals.

[0067] The wireless control unit 6001 performs information processing on layers higher than the physical layer, such as the MAC layer and LLC layer, for information handled within the wireless communication device itself (such as information related to frames to be transmitted and MIB (Management Information Base)) and frames received from other wireless communication devices, and also controls the wireless communication unit 5003.

[0068] The physical layer frame generating unit 5003a has a function of generating a physical layer frame (PPDU). The physical layer frame generating unit 5003a performs error correction coding, modulation, beamforming processing (precoding processing), etc. on the MAC layer frame transmitted from the wireless control unit 6001. The beamforming processing may be realized by multiplying the modulated signal by a beamforming matrix (beamforming filter) notified from the wireless control unit 6001. The physical layer frame generating unit 5003a outputs the generated physical layer frame to the wireless transmission unit 5003b.

[0069] The received power measuring unit 5003d measures the received power of the received signal input from the wireless receiving unit 5003c. The received power measuring unit 5003d can measure the received power of the radio wave received on the frequency channel to be measured, the received power of the LTF (L-LTF, HT-LTF, VHT-LTF, HE-LTF, etc.) of the received physical layer frame, etc. The received power measuring unit 5003d can notify the wireless control unit 6001 of the measurement result of the received power.

[0070] The channel estimation unit 5003e estimates the channel state through which the physical layer frame has propagated based on the received signal of the LTF included in the physical layer frame received by the wireless receiving unit 5003c. The channel estimation unit 5003e can notify the signal demodulation unit 5003f and the wireless control unit 6001 of the channel estimation result.

[0071] The signal demodulation unit 5003f performs channel equalization, demodulation, error correction decoding, etc. on the physical layer frame received by the wireless receiving unit 5003c, and acquires information such as a PHY header and a MAC layer frame. The channel equalization process can use the channel estimation result from the channel estimation unit 5003e. The signal demodulation unit 5003f outputs the acquired PHY header and MAC layer frame to the wireless control unit 6001.

[0072] When there is control information, data, a beacon, or the like to be transmitted, the wireless control unit 6001 can start a back-off procedure using the state determination information of the wireless channel. The wireless control unit 6001 generates a back-off counter based on the CW and has a count-down function of the back-off counter. For example, when the state determination information of the wireless channel indicates an idle state, the wireless control unit 6001 can execute count-down of the back-off counter, and when the state determination information of the wireless channel indicates a busy state, the wireless control unit 6001 can stop count-down of the back-off counter. Furthermore, the wireless control unit 6001 makes a transmission decision using either or both of the state determination information of the wireless channel and the value of the back-off counter. For example, when the state determination information of the wireless channel indicates an idle state and the value of the back-off counter is 0, the wireless control unit 6001 can notify the wireless communication unit 5003 of transmission decision information. Furthermore, when the state determination information of the wireless resource indicates an idle state, the wireless control unit 6001 can notify the wireless communication unit 5003 of transmission decision information.

[0073] Fig. 7 is a diagram showing an example of a sounding procedure in the wireless communication system according to this embodiment. In Fig. 7, it is assumed that a wireless link (first wireless link) between the access point device 4001 and the station device 4002 is established, and an example of a communication flow in the wireless link is shown on the left side, and an example of a state transition of a timer 5002-1 (also called a first timer) included in the timer unit 5002 of the station device 4002 is shown on the right side. In Fig. 7, the timer 5002-1 is assumed to be in an inactive state (7101) at the start.

[0074] The access point device 4001 generates control information (first control information) including setting information on a timer 5002-1 included in the station device 4002, a sounding frame transmission condition from the station device 4002, and transmits a radio frame 7001 including the control information to the station device 4002. The setting information on the timer 5002-1 may include a timer count initial value, a timer count expiration value, timer activation instruction information, timer reset instruction information, timer reset timing information, and the like.

[0075] The station device 4002 that has received the wireless frame 7001 including the first control information acquires the first control information included in the wireless frame 7001, sets the timer count initial value of the timer 5002-1 according to the first control information, and activates the timer (7002). The activation 7002 resets the timer 5002-1 to the timer count initial value, transitions from the inactive state 7101 to the active state 7102, and starts a countdown operation. The timer 5002-1 continues counting down while in the active state. Note that, in FIG. 7, an example has been described in which the setting of the timer count initial value of the timer 5002-1, the reset, the activation, the start of the countdown, and the like are executed all at once by receiving the wireless frame 7001, but this is not limited thereto. For example, the setting and reset of the timer count initial value, the activation, and the start of the countdown may each be executed by being triggered by a different wireless frame (or the control information included in the wireless frame).

[0076] 7, timer 5002-1 is assumed to be a countdown timer, and an example has been described in which a preset timer count initial value is set by resetting, and the timer expires when the count reaches 0, but the present invention is not limited to this, and for example, the timer count expiration value may be set separately to a value other than 0. Alternatively, timer 5002-1 may be configured as a count-up timer that is initialized to a count of 0 by resetting, and expires when the count reaches a preset timer count expiration value.

[0077] When the station device 4002 receives a radio frame (first radio frame) 7003 requiring a response and detects no error in the radio frame 7003, it transmits an Ack frame 7004 as a response frame to the radio frame 7003, and then transmits a sounding frame 7005 (hereinafter, the sounding frame transmitted through the first radio link is also referred to as the first sounding frame), and resets (7006) the timer 5002-1 to the timer count initial value. The reset timer 5002-1 continues to be in an active state (7103) and starts counting down from the timer count initial value. The timing of resetting (7006) the timer 5002-1 is not limited to the time of transmitting the sounding frame 7005, and can be set within a range in which the effect is not changed, such as between the timing of transmitting the Ack frame 7004 and the timing of transmitting the sounding frame 7005.

[0078] The radio frame requiring a response is not limited to a data frame, but may be a frame including control information requiring a response. The Ack frame 7004 and the sounding frame 7005 are preferably transmitted at SIFS intervals, but this is not limiting, and other IFS intervals used for high priority may be used. Furthermore, the Ack frame and the sounding frame may be transmitted in a linked manner. Also, a new frame combining the Ack frame and the sounding frame may be defined and transmitted.

[0079] Sounding frame 7005 may be transmitted and timer 5002-1 may be reset only when the count of timer 5002-1 has reached a predetermined value (is equal to or less than the predetermined value) when wireless frame 7003 is received. In this case, sounding frame transmission is suppressed when timer 5002-1 has not reached the predetermined value, i.e., when the time elapsed since the previous sounding frame transmission is less than the predetermined time, and overhead due to sounding frame transmission can be reduced.

[0080] The radio frame 7003 may be a data frame for transmitting an A-MPDU in which multiple MPDUs are aggregated, and the Ack frame may be a BlockAck frame. When the BlockAck frame is used, the sounding frame 7005 may be transmitted and the timer 5002-1 may be reset only when the number or ratio of positive responses included in the BlockAck is less than a predetermined value. In this case, when the timer 5002-1 has not expired and the state of the wireless link is good, the transmission of the sounding frame is suppressed, and the overhead due to the sounding frame transmission can be reduced.

[0081] When the timer 5002-1 counts down to 0 and enters an expiration state (7104), the station equipment 4002 enters a sounding frame transmission standby state (7007). When the timer 5002-1 expires, the station equipment 4002 performs carrier sense to confirm that the wireless channel is in an idle state, and then starts a backoff procedure (7008). If the wireless channel is in an idle state during the backoff period, the station equipment 4002 transmits a sounding frame 7009 and resets the timer 5002-1 (7010). The timer 5002-1 is reset to the timer count initial value, transitions to an active state, and starts a countdown operation (7105).

[0082] When the station device 4002 receives a radio frame 7011 including control information (fourth control information) including information such as setting cancellation related to the timer 5002-1, the station device 4002 deactivates the timer 5002-1 (7012). The deactivated timer 5002-1 stops the countdown operation and transitions to the inactive state 7106.

[0083] The sounding frames 7005 and 7009 may be, for example, an NDP frame or a set of an NDP Announcement frame and an NDP frame, but are not limited to these, and may be any frame that includes a signal that can estimate the channel between the station device 4002 and the access point device 4001.

[0084] The access point device 4001, which receives sounding frames 7005, 7009 from the station device 4002, may, for example, perform channel estimation between the station device 4002 and the access point device 4001 based on the received sounding frames, and calculate a channel matrix, a beamforming matrix (beamforming filter), etc.

[0085] As a modified example, when the first control information is not directly received from the access point device 4001 but other control information (third control information) is received, the station device 4002 may generate information corresponding to the first control information based on the received control information. As an example, when the station device 4002 receives setting information related to QoS (Quality of Service), the station device 4002 may set a timer count initial value of the timer 5002-1 and activate the timer (7002). The station device 4002 may change the timer count initial value according to the conditions required for QoS. When the allowable delay time is set to be short, the timer count initial value may be reduced. When the bit rate guarantee is set, the timer count initial value may be reduced. The station device 4002 may set the timer count initial value of the timer 5002-1 based on capability information exchanged with the access point device 4001. The QoS setting may be set by the access point device 4001 according to the current traffic situation, or may be set by an application executed on the network. Furthermore, an application running on the network may obtain the QoS settings via the access point device 4002 .

[0086] As a modified example, when the fourth control information is not received directly from the access point device 4001 but other control information is received, the station device 4002 may generate information corresponding to the fourth control information based on the received control information. As an example, when setting information related to QoS is received, the station device 4002 may deactivate the timer 5002-1 (7012). When the allowable delay time is set to be long, the timer 5002-1 may be deactivated. Also, when the bit rate setting is set to best effort, the timer 5002-1 may be deactivated.

[0087] As a modified example, an example of a sounding procedure in which the timer unit 5002 of the station device 4002 includes a timer 5002-2 (also referred to as a third timer) in addition to the timer 5002-1 (first timer) is shown in Fig. 8. In the following, differences from the example of the sounding procedure in Fig. 7 will be mainly described, and explanations of similar parts will be omitted. Also, parts corresponding to those in Fig. 7 will be described with the same reference numerals.

[0088] 8 assumes that a wireless link (first wireless link) between the access point device 4001 and the station device 4002 is established, and shows an example of a communication flow in the wireless link on the left side, and an example of state transition of timers 5002-1 and 5002-2 included in the timer unit 5002 of the station device 4002 on the right side. Also, in FIG. 8, it is assumed that the timers 5002-1 and 5002-2 are in an inactive state (7101, 7201) at the start.

[0089] Unlike the example of Fig. 7, the first control information included in the wireless frame 7001 transmitted from the access point device 4001 to the station device 4002 is generated to include setting information on the timer 5002-2 in addition to setting information on the timer 5002-1 and a sounding frame transmission condition from the station device 4002, and the wireless frame 7001 including the control information is transmitted to the station device 4002. The setting information on the timers 5002-1 and 5002-2 may include timer count initial values, timer count expiration values, timer activation instruction information, timer reset instruction information, timer reset timing information, etc., for each timer. Here, each setting information may be selected so that the time until timer expiration of the timer 5002-2 is shorter than the time until timer expiration (count number) of the timer 5002-1.

[0090] The station device 4002, which has received a wireless frame 7001 including first control information, acquires the first control information included in the wireless frame 7001, sets timer count initial values ​​of the timers 5002-1 and 5002-2 according to the first control information, and activates both timers (7002, 7202). By the activation 7002, the timers 5002-1 and 5002-2 are reset to their timer count initial values, and transition from the inactive state 7101 and the inactive state 7201 to the active state 7102 and the active state 7202, respectively, and start a countdown operation. The timers 5002-1 and 5002-2 continue counting down while in the active state. In addition, in FIG. 8, an example has been described in which the setting, resetting, activation, and countdown start of timers 5002-1 and 5002-2 and the like are performed all at once upon receiving radio frame 7001. However, this is not limited to this, and for example, the setting and resetting of timer count initial values ​​and the like, activation, and countdown start may each be performed using a different radio frame (or control information contained therein) as a trigger.

[0091] 8, timers 5002-1 and 5002-2 are assumed to be countdown timers, and an example has been described in which timers are reset to a preset timer count initial value and reach an expiration state when the count reaches 0, but the present invention is not limited to this, and for example, the timer count expiration value may be separately set to a value other than 0. Alternatively, timers 5002-1 and 5002-2 may be configured as count-up timers that are initialized to a count of 0 when reset and reach an expiration state when the count reaches a preset timer count expiration value.

[0092] When the station device 4002 receives a radio frame (first radio frame) 7003 that requires a response and detects no error in the radio frame 7003, it transmits an Ack frame 7004 as a response frame to the radio frame 7003. At this time, if the timer 5002-2 has not expired (if it is in an active state), the station device 4002 does not transmit a sounding frame 7005 following the Ack frame 7004, unlike the example in Fig. 7. At this time, the timer 5002-1 is not reset, and the timers 5002-1 and 5002-2 continue to be in the active state.

[0093] If the active state continues, timer 5002-2 will reach count 0 earlier than timer 5002-1 and transition to the expired state (7203). At this time, timer 5002-2 will display the fact that it has reached the expired state (7051).

[0094] When the station device 4002 receives a wireless frame 7051 requiring a response and detects no error in the wireless frame 7051, it transmits an Ack frame 7052 as a response frame to the wireless frame 7051. At this time, if the timer 5002-2 has expired (7203), it transmits a sounding frame 7053 following the Ack frame 7052 and resets the timers 5002-1 and 5002-2 to their timer count initial values ​​(7054). The reset timers 5002-1 and 5002-2 enter an active state (7103, 7204) and start counting down from their timer count initial values. The timing of resetting (7054) timers 5002-1 and 5002-2 is not limited to the time of transmitting sounding frame 7053, but can be set anywhere between the timing of transmitting Ack frame 7052 and the timing of transmitting sounding frame 7053, as long as the effect is not affected.

[0095] The radio frame requiring a response is not limited to a data frame, but may be a frame including control information requiring a response. The Ack frame 7052 and the sounding frame 7053 are preferably transmitted at SIFS intervals, but this is not limiting, and other IFS intervals used for high priority may be used. Furthermore, the Ack frame and the sounding frame may be transmitted in a linked manner. Also, a new frame combining the Ack frame and the sounding frame may be defined and transmitted.

[0096] The radio frame 7051 may be a data frame for transmitting an A-MPDU in which multiple MPDUs are aggregated, and the Ack frame may be a BlockAck frame. When the BlockAck frame is used, the sounding frame 7053 may be transmitted and the timers 5002-1 and 5002-2 may be reset only when the number or ratio of positive responses included in the BlockAck is less than a predetermined value. In this case, when the timer 5002-1 has not expired and the state of the wireless link is good, the transmission of the sounding frame is suppressed, and the overhead due to the transmission of the sounding frame can be reduced.

[0097] The station equipment 4002 indicates (7055) that the timer 5002-2 has counted down to 0 and is in an expired state (7205), and when the timer 5002-1 has counted down to 0 and is in an expired state (7104), the station equipment 4002 enters a sounding frame transmission standby state (7007). When the timer 5002-1 has expired, the station equipment 4002 performs carrier sense to confirm that the wireless channel is in an idle state, and then starts a backoff procedure (7008). If the wireless channel is in an idle state during the backoff period, the station equipment 4002 transmits a sounding frame 7009 and resets the timers 5002-1 and 5002-2 (7010). The timers 5002-1 and 5002-2 are reset to their timer count initial values, transition to an active state, and start countdown operations (7105, 7206).

[0098] Unlike the example of Fig. 7, the fourth control information included in the wireless frame 7011 transmitted from the access point device 4001 to the station device 4002 may include information such as deactivation of the timer 5002-2 in addition to information such as deactivation of the timer 5002-1. The deactivation information of the timer 5002-2 may be common information to the information of deactivation of the timer 5002-1. When the station device 4002 receives the wireless frame 7011 including the fourth control information, it deactivates the timers 5002-1 and 5002-2 (7012). The deactivated timers 5002-1 and 5002-2 stop counting down and transition to the inactive states 7106 and 7207.

[0099] Also, as a modified example, when the first control information is not directly received from the access point device 4001 but other control information is received, the station device 4002 may generate information corresponding to the first control information based on the received control information. As an example, when the setting information related to QoS is received, the station device 4002 may set the timer count initial values ​​of the timers 5002-1 and 5002-2 and activate them (7002). The station device 4002 may change the timer count initial values ​​according to the conditions required for QoS. When the allowable delay time is set to be short, the timer count initial values ​​may be reduced. When the bit rate guarantee is set, the timer count initial values ​​may be reduced. The station device 4002 may set the timer count initial values ​​of the timers 5002-1 and 5002-2 based on the capability information exchanged with the access point device 4001. The QoS setting may be set by the access point device 4001 according to the current traffic situation, or may be set by an application executed on the network. Furthermore, an application running on the network may obtain the QoS settings via the access point device 4002 .

[0100] As a modified example, when the fourth control information is not received directly from the access point device 4001 but other control information is received, the station device 4002 may generate information corresponding to the fourth control information based on the received control information. As an example, when setting information related to QoS is received, the station device 4002 may deactivate the timers 5002-1 and 5002-2 (7012). When the allowable delay time is set to be long, the timers 5002-1 and 5002-2 may be deactivated. Also, when the bit rate setting is set to best effort, the timers 5002-1 and 5002-2 may be deactivated.

[0101] FIG. 9 shows a flowchart of an example of a sounding procedure in the station device 4002 when the timers 5002-1 and 5002-2 are used.

[0102] When the station device 4002 transmits an Ack frame (Yes in step S9001), it checks whether the timer 5002-2 has expired (step S9002). If the timer 5002-2 has expired (Yes in step S9002), it transmits a sounding frame following the transmission of the Ack frame (step S9003), resets the timers 5002-1 and 5002-2 (step S9004), and returns to step S9001.

[0103] If the answer is No in step S9001, it is checked whether the timer 5002-1 has expired (step S9005). If the timer 5002-1 has not expired (No in step S9005), the process returns to step S9001. If the timer 5002-1 has expired (Yes in step S9005), carrier sense is executed (step S9006), a back-off procedure is executed (step S9007), a sounding frame is transmitted (step S9008), the timers 5002-1 and 5002-2 are reset (step S9009), and the process returns to step S9001. Although not shown, if the wireless channel becomes busy during the carrier sense and back-off procedure, the process is retried from step S9006, but if a wireless frame to be received is detected, the process returns to step S9001.

[0104] Next, as a modified example, an example will be described in which the access point device 4001 and the station device 4002 are compatible with Multi-Link Operation (MLO), in which communication is performed simultaneously using two wireless links, a first wireless link and a second wireless link using a frequency band (or frequency channel) different from that of the first wireless link. Note that MLO is not limited to two wireless links, and multiple wireless links in different frequency bands (or frequency channels) can be used.

[0105] A multi-link device (MLD) is a device capable of multi-link communication by multi-link operation, and an access point device that supports MLO is called an MLD access point device, and a station device that supports MLO 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 wireless communication devices 4001-1, 4001-2, 4002A, and 4002B described above are described as MLD wireless communication devices, but in actual operation, all wireless communication devices in a wireless communication system do not necessarily support MLO.

[0106] The MLD access point device 10001 and the MLD station device 10002 will be described with reference to Fig. 10. The MLD wireless communication device is composed of a plurality of sub-wireless communication devices corresponding to the frequency bands (or frequency channels) of the wireless links (also called physical layer links) constituting the multilink. Each sub-wireless communication device may be compatible with all frequency bands (and frequency channels) supported by the MLD wireless communication device, or each may be compatible with any frequency band (or frequency channel). Fig. 10 shows an example in which the MLD access point device 10001 is composed of two sub-wireless communication devices, in this case two sub-access point devices 10001-1 and 10001-2, and a multilink control unit 10011, but the number of sub-access point devices is any number equal to or greater than two. In the following description, when any one of the plurality of sub-access point devices is described as a representative, it is called a sub-access point device 10001-N. 10 shows an example in which the MLD station device 10002 is similarly configured with two sub wireless communication devices, in this case two substation devices 10002-1 and 10002-2, and a multilink control unit 10012, but the number of substation devices is any number equal to or greater than two. In the following, when any one of the multiple substation devices is described as a representative, it is referred to as a substation device 10002-N. Also, the sub wireless communication devices (sub access point devices and substation devices) may be configured with a portion of the circuitry within the wireless communication device, and may be referred to as sub wireless communication units (sub access point units, substation units).

[0107] 10 shows an example in which a plurality of sub-wireless communication devices are configured as logically separate blocks, but may be configured as one physical wireless communication device. Alternatively, a plurality of sub-wireless communication devices may be configured as physically separate devices. In this embodiment, a case in which each sub-wireless communication device is configured as a physically separate device will be described as an example.

[0108] 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, for each MLD wireless communication device present in one wireless communication system, the sub-wireless communication devices (sub-access point devices, substation devices) that make up each MLD wireless communication device may differ depending on the grade, class, capability, etc., and the numbers of these devices do not have to be the same.

[0109] The substation apparatus 10002-1 connects (associates) with the sub-access point apparatus 10001-1 and establishes a wireless link 10003-1 (first wireless link), and the substation apparatus 10002-2 connects with the sub-access point apparatus 10001-2 and establishes a wireless link 10003-2 (second wireless link).

[0110] The configuration of the sub-access point device 10001-N in Fig. 10 is the same as that of the access point device 4001 in Fig. 6, except that a multi-link control unit 10011 is connected to a wireless control unit 6001 of each sub-access point device 10001-N. The multi-link control unit 10011 controls wireless links for each sub-access point device 10001-N and exchanges control information and transmission / reception data with each sub-access point device 10001-N. The multi-link control unit 10011 distributes transmission data frames to the sub-access point devices 10001-1 and 10001-2, i.e., the wireless links 10003-1 and 10003-2, and aggregates received data frames from the sub-access point devices 10001-1 and 10001-2, i.e., the wireless links 10003-1 and 10003-2.

[0111] On the other hand, the configuration of the substation device 10002-N in Fig. 10 is the same as that of the station device 4002 in Fig. 5, except that a multilink control unit 10012 is connected to a wireless control unit 5001 of each substation device 10002-N. The multilink control unit 10012 controls wireless links for each substation device 10002-N, and transmits and receives control information and transmission / reception data between each substation device 10002-N. The multilink control unit 10012 distributes transmission data frames to each of the substation devices 10002-1 and 10002-2, i.e., each of the wireless links 10003-1 and 10003-2, and aggregates received data frames from each of the substation devices 10002-1 and 10002-2, i.e., each of the wireless links 10003-1 and 10003-2.

[0112] In the following description, for the sake of simplicity, an example will be described in which the wireless links constituting the multilink are two, wireless link 10003-1 (first wireless link) and wireless link 10003-2 (second wireless link), but the present invention is not limited to this and can be similarly applied to a case in which the number of wireless links is three or more. In addition, an example will be described in which the frequency band of the first wireless link is 2.4 GHz and the frequency band of the second wireless link is 5 GHz, but the frequency band used by each wireless link can be arbitrarily set from frequency bands (or frequency channels) supported by the wireless communication system, such as 2.4 GHz, 5 GHz, 6 GHz, and 60 GHz, and these may change according to the laws and regulations of each country.

[0113] An example of a sounding procedure in this modified example will be described. The operation in each wireless link is the same as the operation in the case where there is one wireless link shown in FIG. 7. That is, in the first wireless link, the sub-access point device 10001-1 performs the same operation as the access point device 4001 in FIG. 7, and the substation device 10002-1 performs the same operation as the station device 4002 in FIG. 7. In the second wireless link, the sub-access point device 10001-2 performs the same operation as the access point device 4001 in FIG. 7, and the substation device 10002-2 performs the same operation as the station device 4002 in FIG. 7. Here, the timer included in the timer unit 5002 of the substation device 10002-1 is called the timer 5002-1 (first timer) as in FIG. 7, and the timer included in the timer unit 5002 of the substation device 10002-2 is called the timer 5002-3 (second timer). The following description will focus on the differences from the example of the sounding procedure in FIG. 7, and will omit a description of the similarities.

[0114] The operation of the first wireless link is the same as that of FIG. 7, and therefore the description will be omitted. In the second wireless link, when the substation device 10002-2 receives from the sub-access point device 10001-2 a wireless frame 7001-2 (replace 7001 in FIG. 7; the same applies below) including second control information including setting information on the timer 5002-3 and a sounding frame transmission condition from the substation device 10002-2, the substation device 10002-2 sets a timer count initial value of the timer 5002-3 and activates the timer (7002-2). The setting information on the timer 5002-3 may include a timer count initial value, a timer count expiration value, timer activation instruction information, timer reset instruction information, timer reset timing information, and the like. The activation 7002-2 resets the timer 5002-3 to the timer count initial value, transitions from the inactive state 7101-2 to the active state 7102-2, and starts a countdown operation. The timer 5002-3 continues counting down while in the active state. Note that, although an example has been described in which the setting of the timer count initial value, resetting, activation, and countdown start of the timer 5002-3 are executed all at once by receiving the wireless frame 7001-2, the present invention is not limited to this, and for example, the setting and resetting of the timer count initial value, activation, and countdown start may each be triggered by (control information contained in) a different wireless frame.

[0115] Also, timer 5002-3 is assumed to be a countdown timer, and an example has been described in which it is reset to a preset timer count initial value and reaches the expiration state when the count reaches 0, but this is not limiting, and for example, the timer count expiration value may be separately set to a value other than 0. Alternatively, timer 5002-3 may be a count-up timer that is initialized to a count of 0 when reset, and reaches the expiration state when the count reaches a preset timer count expiration value.

[0116] When the substation apparatus 10002-2 receives a wireless frame (second wireless frame) 7003-2 requiring a response and detects no error in the wireless frame 7003-2, it transmits an Ack frame 7004-2 as a response frame to the wireless frame 7003-2, then transmits a sounding frame 7005-2 (hereinafter, the sounding frame transmitted via the second wireless link is also referred to as the second sounding frame), and resets (7006-2) the timer 5002-3 to the timer count initial value. The reset timer 5002-3 continues the active state (7103-2) and starts counting down from the timer count initial value. The timing of resetting (7006-2) the timer 5002-3 is not limited to the time when the sounding frame 7005-2 is transmitted, but can be set to any time between the timing of transmitting the Ack frame 7004-2 and the timing of transmitting the sounding frame 7005-2, as long as the effect is not changed.

[0117] The radio frame requiring a response is not limited to a data frame, but may be a frame including control information requiring a response. The transmission of the Ack frame 7004-2 and the sounding frame 7005-2 is preferably performed at intervals of SIFS, but this is not limiting, and other IFS used in cases of high priority may be used. Furthermore, the Ack frame and the sounding frame may be linked and transmitted. Also, a new frame combining the Ack frame and the sounding frame may be defined, and this frame may be transmitted.

[0118] When receiving the wireless frame 7003-2, only when the count of the timer 5002-3 reaches a predetermined value (is equal to or less than the predetermined value), the sounding frame 7005-2 may be transmitted and the timer 5002-3 may be reset. In this case, when the timer 5002-3 does not reach the predetermined value, that is, when the time elapsed since the previous sounding frame transmission is less than the predetermined time, the transmission of the sounding frame is suppressed, and the overhead due to the sounding frame transmission can be reduced.

[0119] The radio frame 7003-2 may be a data frame for transmitting an A-MPDU in which multiple MPDUs are aggregated, and the Ack frame may be a BlockAck frame. When the BlockAck frame is used, the sounding frame 7005-2 may be transmitted and the timer 5002-3 may be reset only when the number or ratio of positive responses included in the BlockAck is less than a predetermined value. In this case, when the timer 5002-3 has not expired and the state of the radio link is good, the transmission of the sounding frame is suppressed, and the overhead due to the sounding frame transmission can be reduced.

[0120] When the timer 5002-3 reaches 0 and is in an expiration state (7104-2), the substation equipment 10002-2 enters a sounding frame transmission standby state (7007-2). When the timer 5002-3 is expired, the substation equipment 10002-2 performs carrier sense to confirm that the wireless channel is in an idle state, and then starts a backoff procedure (7008-2). If the wireless channel is in an idle state during the backoff period, the substation equipment 10002-2 transmits a sounding frame 7009-2 and resets the timer 5002-3 (7010-2). The timer 5002-3 is reset to the timer count initial value, transitions to an active state, and starts a countdown operation (7105-2).

[0121] When the substation device 10002-2 receives a radio frame 7011-2 including control information (sixth control information) including information such as setting cancellation related to the timer 5002-3, the substation device 10002-2 deactivates the timer 5002-3 (7012-2). The deactivated timer 5002-3 stops counting down and transitions to an inactive state 7106. When the substation device 10002-1 receives the fourth control information in the first radio link, the substation device 10002-2 may also deactivate the timer 5002-3. When the substation device 10002-2 receives the sixth control information in the second radio link, the substation device 10002-1 may also deactivate the timer 5002-1.

[0122] Also, as a modified example, when the second control information is not directly received from the sub-access point device 10001-2 but other control information (fifth control information) is received, the substation device 10002-2 may generate information corresponding to the second control information based on the received control information. As an example, when the setting information related to QoS is received, the substation device 10002-2 may set a timer count initial value of the timer 5002-3 and then activate (7002-2). The substation device 10002-2 may change the timer count initial value according to the conditions required as QoS. When the allowable delay time is set to be short, the timer count initial value may be reduced. When the bit rate guarantee is set, the timer count initial value may be reduced. The substation device 10002-2 may set a timer count initial value of the timer 5002-3 based on the capability information exchanged with the sub-access point device 10001-2. The QoS settings may be set by the sub-access point device 10001-2 depending on the current traffic situation, or may be set by an application running on the network. Also, the application running on the network may obtain the QoS settings via the sub-access point device 10001-2.

[0123] As a modified example, when the sixth control information is not directly received from the sub-access point device 10001-2 but other control information is received, the substation device 10002-2 may generate information corresponding to the sixth control information based on the received control information. As an example, when setting information related to QoS is received, the substation device 10002-2 may deactivate the timer 5002-3 (7012-2). When the allowable delay time is set to be long, the timer 5002-3 may be deactivated. Also, when the bit rate setting is set to best effort, the timer 5002-3 may be deactivated.

[0124] Also, the substation device 10002-2 connected to the sub-access point device 10001-2 may be provided with a plurality of timers for sounding control. The substation device 10002-2 may be provided with a second timer and a fourth timer similar to the first timer and the third timer, and may be configured not to transmit a sounding frame if the fourth timer has not expired when transmitting a response frame. Also, the substation device 10002-2 may be configured to perform carrier sense when the second timer expires, confirm that the wireless channel of the second link is in an idle state, and then perform back-off processing to transmit a sounding frame. After transmitting the sounding frame, the substation device 10002-2 may reset the second timer and the fourth timer. The timer expiration time of the second timer may be set to be shorter than the time until the fourth timer expires.

[0125] When configured as MLD, when a station device receives control information for changing settings such as a timer count initial value in one of the active links, the station device may activate or deactivate the timer for the active links other than the link that received this control information. Also, when setting information related to QoS is received in one of the active links, the station device may activate or deactivate the timer for the active links other than the link that received the QoS information.

[0126] According to the method described above, it is possible to maintain good communication quality of a radio link in wireless communication. [2. Common to all embodiments]

[0127] 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 frequency 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.

[0128] The program that operates in the wireless communication device according to the present invention is a program that controls the CPU and the like (a program that makes a computer function) so as to realize the functions of the above-mentioned 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 read, modified, and written by the CPU as necessary. The recording medium that stores 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.), and magnetic recording media (e.g., magnetic tape, flexible disk, etc.). In addition, not only the functions of the above-mentioned embodiments are realized by executing the loaded program, but also the functions of the present invention may be realized by processing in cooperation with an operating system or other application programs based on instructions from the program.

[0129] 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.

[0130] 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.

[0131] 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.

[0132] 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 that do not deviate from the gist of the present invention are also included in the scope of the claims. [Industrial Applicability]

[0133] The present invention is suitable for use in a wireless communication device and a wireless communication method. [Explanation of symbols]

[0134] 3001 NDP Announcement Frame 3002 NDP Frame 3003 Compressed Beamforming / CQI Frame 4001-1, 4001-2 Wireless communication device (access point device) 4002-1~6 Wireless communication equipment (station equipment) 4003-1, 4003-2 Wireless communication systems 5001 Radio control unit 5002 Timer section 5003 Wireless Communication Department 5003a Physical layer frame generator 5003b Radio transmitter 5003c Wireless receiver 5003d Received power measurement unit 5003e Channel Estimation Unit 5003f Signal demodulation section 5004 Antenna part 6001 Radio control unit 10001 MLD access point device 10001-1 Sub-access point device 10001-2 Sub-access point device 10002 MLD station equipment 10002-1 Substation equipment 10002-2 Substation equipment 10003-1 First radio link 10003-2 Second radio link 10011 Multi-link control unit 10012 Multi-link control unit

Claims

1. A wireless communication device that communicates with a wireless communication device of a communication partner using a wireless link, a wireless communication unit that transmits and receives wireless frames via a first wireless link; a wireless control unit including a first timer; the wireless control unit activates the first timer when the wireless communication unit receives a wireless frame including first control information indicating that the first timer is to be set; When a first wireless frame requiring a response is received in the first wireless link, the wireless communication unit transmits a first response frame in response to the first wireless frame, and then transmits a first sounding frame without carrier sense, and the wireless control unit resets the first timer; When the first timer expires, the wireless communication unit transmits the first sounding frame after performing carrier sense in the first wireless link, and the wireless control unit resets the first timer.

23. A wireless communication device comprising:

2. the wireless communication device is a wireless communication device that communicates with the wireless communication device of the communication partner by simultaneously using a plurality of wireless links including the first wireless link and a second wireless link having a frequency band different from that of the first wireless link, the wireless communication unit further transmits and receives wireless frames via the second wireless link; the wireless control unit further includes a second timer; the wireless control unit activates the second timer when the wireless communication unit receives a wireless frame including second control information indicating that the second timer is to be set; When a second wireless frame requiring a response is received in the second wireless link, the wireless communication unit transmits a second response frame in response to the second wireless frame, and then transmits a second sounding frame without carrier sense, and the wireless control unit resets the second timer; When the second timer expires, the wireless communication unit transmits the second sounding frame after performing carrier sense in the second wireless link, and the wireless control unit resets the second timer.

2. The wireless communication device according to claim 1 .

3. if the first timer has reached a predetermined value when the first radio frame is received, The wireless communication unit transmits the first sounding frame without carrier sense following the transmission of the first response frame.

2. The wireless communication device according to claim 1 .

4. If the first response frame is a block response frame, When the number of acknowledgments included in the block response frame is less than a predetermined number, the wireless communication unit transmits the first sounding frame without carrier sense following transmission of the block response frame.

2. The wireless communication device according to claim 1 .

5. The wireless control unit sets an expiration condition of the first timer and resets the first timer when the wireless communication unit receives a wireless frame including third control information.

2. The wireless communication device according to claim 1 .

6. 6. The wireless communication device according to claim 5, wherein the third control information is information for setting a quality of service (QoS).

7. 2 . The wireless communication device according to claim 1 , wherein the wireless control unit deactivates the first timer when the wireless communication unit receives a wireless frame including fourth control information.

8. 8. The wireless communication device according to claim 7, wherein the fourth control information is information for canceling a QoS setting.

9. the wireless control unit further includes a third timer, and when the wireless communication unit receives a wireless frame including the first control information, activates the first timer and the third timer; When the third timer has expired when the wireless communication unit receives the first wireless frame, the wireless communication unit transmits the first sounding frame without carrier sense following the transmission of the first response frame, and the wireless control unit resets the first timer and the third timer; When the first timer expires, the wireless communication unit transmits the first sounding frame after performing carrier sense on the first wireless link, and the wireless control unit resets the first timer and the third timer.

2. The wireless communication device according to claim 1 .

10. if the first timer has reached a predetermined value when the first wireless frame is received, the wireless communication unit transmits the first sounding frame without carrier sense following the transmission of the first response frame; If the second timer has reached a predetermined value when the second wireless frame is received, the wireless communication unit transmits the second sounding frame without carrier sense following the transmission of the second response frame.

3. The wireless communication device according to claim 2.

11. When the first response frame or the second response frame is a block response frame, When the number of acknowledgments included in the block response frame is less than a predetermined number, the wireless communication unit transmits the first sounding frame or the second sounding frame without carrier sense following transmission of the block response frame.

3. The wireless communication device according to claim 2.

12. The wireless control unit includes: When the wireless communication unit receives a wireless frame including third control information, an expiration condition of the first timer is set and the first timer is reset; When the wireless communication unit receives a wireless frame including fifth control information, an expiration condition of the second timer is set, and the second timer is reset.

3. The wireless communication device according to claim 2.

13. The wireless control unit includes: deactivating the first timer when the wireless communication unit receives a wireless frame including fourth control information; When the wireless communication unit receives a wireless frame including sixth control information, the second timer is deactivated.

3. The wireless communication device according to claim 2.

14. A wireless communication device that communicates with a wireless communication device of a communication partner using a wireless link, a wireless communication unit that transmits and receives wireless frames via a first wireless link; A radio control unit that generates control information, the wireless control unit generates first control information including setting and reset conditions for a first timer included in the wireless communication device of the communication partner and a transmission condition for a sounding frame from the wireless communication device of the communication partner; The first wireless communication unit transmits a wireless frame including the first control information.

23. A wireless communication device comprising:

15. A communication method in a wireless communication device that communicates with another wireless communication device using a wireless link, comprising: receiving a radio frame including first control information indicating setting a first timer; activating the first timer when receiving a radio frame including the first control information; receiving a first radio frame requiring a response in a first wireless link; transmitting a first response frame to the first radio frame; transmitting a first sounding frame without carrier sense following the transmission of the first response frame, and resetting the first timer; When the first timer expires, transmitting the first sounding frame after performing carrier sensing in the first wireless link and resetting the first timer.

23. A wireless communication method comprising:

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