Base station device and communication method

Abstract

To provide a base station device and a communication method that realizes large-capacity transmission while suppressing an interference signal even when a propagation environment is controlled.SOLUTION: A base station device includes a control unit that controls the reflection direction of a propagation control device, and a transmission unit that transmits a frame for acquiring a wireless medium to a terminal device as a destination, in which the reflection direction is not controlled within a period in which the wireless medium is acquired. The terminal devices are classified into a first terminal device that communicates with control of the propagation control device and a second terminal device that communicates without control of the propagation control device.SELECTED DRAWING: Figure 6

Description

[Technical field]

[0001] The present invention relates to a base station device and a communication method. [Background technology]

[0002] Unlicensed bands are bands that do not require a license and have low operating costs, so they are widely used in wireless LANs (Local Area Networks) and other applications. Wireless LANs support communication in the 60 GHz band, which allows for a wide bandwidth to be used to achieve large-capacity transmission. In high-frequency bands such as the 60 GHz band, beamforming is essential to compensate for the effects of large path loss. In addition, as the frequency increases, radio waves tend to travel in a more directional direction, so if there is an obstruction between communication devices, the radio waves are blocked, making communication difficult.

[0003] IRS (Intelligent Reflecting Surface) can electrically control the propagation environment, such as the reflection direction, so it allows for flexible setting of communication paths and is particularly effective in high frequency bands. IRS is described in Non-Patent Document 1. [Prior art documents] [Non-patent literature]

[0004] [Non-Patent Document 1] E. Basar, MD Renzo, JD Rosny, M. Debbah, MS Alouini, and R. Zhang, “Wireless communications through reconfigurable intelligent surfaces,” IEEE Access, vol. 7, September 2019. Summary of the Invention [Problem to be solved by the invention]

[0005] Generally, in unlicensed bands, communication devices observe the surrounding communication conditions to determine whether or not to transmit. By installing an IRS and controlling the propagation environment, radio waves can reach areas where they could not reach before. This increases the possibility that there are communication devices that cannot be found by observing the surroundings, and interference signals can become a problem.

[0006] The present invention has been made in consideration of the above circumstances, and its object is to provide a base station apparatus and a communication method that realizes large-capacity transmission while suppressing interference signals, even when the propagation environment is controlled. [Means for solving the problem]

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

[0008] A base station device according to one embodiment of the present invention is a base station device that communicates with a terminal device, and is equipped with a control unit that controls the reflection direction of a propagation control device, and a transmitting unit that transmits a frame for acquiring a wireless medium addressed to the terminal device, and does not control the reflection direction during the period in which the wireless medium is acquired.

[0009] In addition, in a base station device according to one embodiment of the present invention, the terminal device is classified into a first terminal device that communicates by controlling the propagation control device, and a second terminal device that communicates without controlling the propagation control device.

[0010] In addition, in the base station device according to one embodiment of the present invention, when a plurality of the first terminal devices are present, In this case, when a frame for acquiring the wireless medium is transmitted to the propagation control device as a destination, the reflection direction is controlled within a period in which the wireless medium is acquired.

[0011] In a base station device according to an aspect of the present invention, the frame is transmitted in a predetermined beam direction or reflection direction.

[0012] Furthermore, a communication method according to one aspect of the present invention is a communication method in a base station device communicating with a terminal device, comprising the steps of controlling the reflection direction of a propagation control device and transmitting a frame for acquiring a wireless medium addressed to the terminal device, and the reflection direction is not controlled during the period in which the wireless medium is acquired. [Brief description of the drawings]

[0013] [Figure 1] FIG. 2 is a diagram illustrating an example of a frame configuration according to an embodiment of the present invention. [Diagram 2] FIG. 2 is a diagram illustrating an example of a frame configuration according to an embodiment of the present invention. [Diagram 3] FIG. 2 is a diagram illustrating an example of communication according to an embodiment of the present invention. [Figure 4] FIG. 2 is a schematic diagram illustrating an example of division of radio resources according to an aspect of the present invention. [Diagram 5] FIG. 1 is a diagram illustrating an example of a configuration of a communication system according to an aspect of the present invention. [Figure 6] 1 is a block diagram showing an example of a configuration of a base station device according to an embodiment of the present invention. [Figure 7] 1 is a block diagram showing an example of a configuration of a terminal device according to an aspect of the present invention. [Figure 8] FIG. 1 is a diagram for explaining a beam sweep according to one embodiment of the present invention. [Figure 9] FIG. 1 is a diagram for explaining a reflection direction sweep according to one embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0014] The communication system in this embodiment includes a wireless transmitting device (access point device, base station device: Access point, base station device, transmission point, transmission / reception point) and multiple wireless receiving devices (station device, terminal device: Station, terminal device, reception point). A network configured with the base station device and the terminal devices is called a basic service set (BSS: Basic service set, management range). The station device according to this embodiment can have the functions of an access point device. Similarly, the access point device according to this embodiment can have the functions of a station device. Therefore, hereinafter, when simply referring to a communication device, the communication device can refer to both a station device and an access point device.

[0015] The base station device and the terminal device in the BSS communicate based on CSMA / CA (Carrier sense multiple access with collision avoidance). In this embodiment, the base station device communicates with a plurality of terminal devices in the infrastructure mode, but the method of this embodiment can also be implemented in the ad-hoc mode in which the terminal devices communicate directly with each other. In the ad-hoc mode, the terminal devices form a BSS in place of the base station device. The BSS in the ad-hoc mode is also referred to as an IBSS (Independent Basic Service Set). In the following, the terminal devices forming the IBSS in the ad-hoc mode can also be considered as the base station device. The method of this embodiment can also be implemented in WiFi Direct (registered trademark) in which the terminal devices directly communicate with each other. In WiFi Direct, the terminal devices form a Group in place of the base station device. In the following, the terminal devices of the Group Owner that form a Group in WiFi Direct can also be considered as the base station device.

[0016] In the IEEE802.11 system, each device can transmit multiple frame types with a common frame format. The transmission frames are defined in the physical (PHY) layer, medium access control (MAC) layer, and logical link control (LLC) layer.

[0017] The transmission frame of the PHY layer is called a physical protocol data unit (PPDU, PHY protocol data unit, physical layer frame). PPDU is composed of a physical layer header (PHY header) that contains header information for signal processing in the physical layer, and a physical service data unit (PSDU, PHY service data unit, MAC layer frame), which is a data unit processed in the physical layer. PSDU can be composed of an aggregated MPDU (A-MPDU), which aggregates multiple MAC protocol data units (MPDUs), which are the retransmission units in the wireless section.

[0018] 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 efficiency STF (HE-STF), and extremely high throughput STF (EHT-STF), depending on 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.

[0019] Furthermore, the PHY header can include information for identifying the BSS that is the source of the transmission frame (hereinafter, also referred to as BSS identification information). The information for identifying the BSS can be, for example, the SSID (Service Set Identifier) ​​of the BSS or the MAC address of the base station device of the BSS. The information for identifying the BSS can also be a value unique to the BSS (for example, BSS Color, etc.) other than the SSID or MAC address.

[0020] The PPDU is modulated according to a corresponding standard, for example, in the case of the IEEE802.11n standard, it is modulated into an Orthogonal Frequency Division Multiplexing (OFDM) signal.

[0021] MPDU is composed of a MAC layer header (MAC header) that contains header information for signal processing at the MAC layer, a MAC service data unit (MSDU) or frame body that is a data unit processed at the MAC layer, and a frame check sequence (FCS) that checks whether there are any errors in the frame. Multiple MSDUs can also be aggregated as an Aggregated MSDU (A-MSDU).

[0022] The frame types of MAC layer transmission frames are broadly classified into three types: management frames that manage the connection status between devices, control frames that manage the communication status between devices, and data frames that contain the actual transmission data. Each type is further classified into multiple subframe types. Control frames include acknowledgement (Ack) frames, request to send (RTS) frames, and clear to send (CTS) frames. Management frames include beacon frames, probe request frames, probe response frames, authentication frames, association request frames, and association response frames. Data frames include data frames and polling (CF-poll) frames. Each device can determine the frame type and subframe type of a received frame by reading the contents of the frame control field included in the MAC header.

[0023] The Ack may include a Block Ack, which is capable of notifying completion of reception of multiple MPDUs.

[0024] The beacon frame includes a field that describes the period (Beacon interval) at which the beacon is transmitted and the SSID. The base station device can periodically broadcast the beacon frame within the BSS, and the terminal device can identify the base station devices around the terminal device by receiving the beacon frame. The terminal device's identification of the base station device based on the beacon frame broadcast by the base station device is called passive scanning. On the other hand, the terminal device's exploration of the base station device by broadcasting a probe request frame within the BSS is called active scanning. The base station device can transmit a probe response frame in response to the probe request frame, and the contents of the probe response frame are equivalent to those of the beacon frame.

[0025] After recognizing a base station device, the terminal device performs a connection process with the base station device. The connection process is classified into an authentication procedure and an association procedure. The terminal device transmits an authentication frame (authentication request) to the base station device to which it wishes to connect. When the base station device receives the authentication frame, it transmits an authentication frame (authentication response) to the terminal device that includes a status code indicating whether the terminal device has been authenticated or not. By reading the status code written in the authentication frame, the terminal device can determine whether or not it has been authorized to be authenticated by the base station device. Note that the base station device and the terminal device can exchange authentication frames multiple times.

[0026] Following the authentication procedure, the terminal device transmits a connection request frame to the base station device to perform a connection procedure. When the base station device receives the connection request frame, it determines whether or not to permit the connection of the terminal device, and transmits a connection response frame to notify the result. The connection response frame contains a status code indicating whether or not the connection process is possible, as well as an association identifier (AID) for identifying the terminal device. The base station device can manage multiple terminal devices by setting different AIDs for each terminal device for which it has issued connection permission.

[0027] After the connection process is completed, the base station device and the terminal device perform actual data transmission. In the IEEE802.11 system, a distributed coordination function (DCF: Distributed Coordination Function), a centralized coordination function (PCF: Point Coordination Function), and their extended functions (enhanced distributed channel access (EDCA) and hybrid coordination function (HCF), etc.) are defined. The following describes an example in which a base station device transmits a signal to a terminal device using DCF.

[0028] In DCF, a base station device and a terminal device perform carrier sense (CS) to check the usage status of a wireless channel around the device before communication. For example, when a base station device, which is a transmitting station, receives a signal higher than a predetermined clear channel assessment level (CCA level) on the wireless channel, it postpones the transmission of a transmission frame on the wireless channel. Hereinafter, a state in which a signal of CCA level or higher is detected on the wireless channel is called a busy state, and a state in which a signal of CCA level or higher is not detected is called an idle state. In this way, CS performed based on the power of a signal actually received by each device (received power level, signal strength) is called physical carrier sense (physical CS). The CCA level is also called a carrier sense level (CS level) or a CCA threshold (CCA threshold: CCAT). When a signal of CCA level or higher is detected, the base station device and the terminal device start an operation of demodulating at least a PHY layer signal.

[0029] The base station device performs carrier sensing for an inter frame space (IFS) that corresponds to the type of transmission frame to be transmitted, and judges whether the wireless channel is busy or idle. The period during which the base station device performs carrier sensing varies depending on the frame type and subframe type of the transmission frame that the base station device is about to transmit. In the IEEE802.11 system, multiple IFSs with different periods are defined, including a short inter frame space (SIFS: Short IFS) used for transmission frames assigned the highest priority, a polling inter frame space (PCF IFS: PIFS) used for transmission frames with relatively high priority, and a distributed control inter frame space (DCF IFS: DIFS) used for transmission frames with the lowest priority. When the base station device transmits a data frame using DCF, the base station device uses DIFS.

[0030] After waiting for the DIFS, the base station device waits for a random backoff time to prevent frame collision. In the IEEE802.11 system, a random backoff time called a contention window (CW) is used. In CSMA / CA, it is assumed that a transmission frame transmitted by a certain transmitting station is received by a receiving station without interference from other transmitting stations. Therefore, if transmitting stations transmit transmission frames at the same timing, the frames collide with each other and the receiving station cannot receive the frames correctly. Therefore, frame collision is avoided by having each transmitting station wait for a randomly set time before starting transmission. When the base station device determines that the wireless channel is in an idle state by carrier sense, it starts counting down the CW, and only when the CW reaches 0 does it acquire the right to transmit and can transmit a transmission frame to the terminal device. Note that if the base station device determines that the wireless channel is in a busy state by carrier sense during the CW countdown, it stops the CW countdown. Then, when the wireless channel becomes idle, the base station device resumes the countdown of the remaining CW following the previous IFS.

[0031] A terminal device, which is a receiving station, receives a transmission frame, reads the PHY header of the transmission frame, and demodulates the received transmission frame. The terminal device can then read the MAC header of the demodulated signal to determine whether the transmission frame is addressed to the terminal device itself. The terminal device can also determine the destination of the transmission frame based on information written in the PHY header (for example, a group identification number (GID: Group identifier, Group ID) written in VHT-SIG-A).

[0032] When a terminal device judges that the received transmission frame is addressed to itself and demodulates the transmission frame without error, it must transmit an ACK frame indicating that the frame was received correctly to the base station device, which is the transmitting station. The ACK frame is one of the highest priority transmission frames that is transmitted only by waiting for the SIFS period (no random backoff time is taken). The base station device ends a series of communications by receiving the ACK frame transmitted from the terminal device. Note that if the terminal device does not receive the frame correctly, the terminal device does not transmit an ACK. Therefore, if the base station device does not receive an ACK frame from the receiving station for a certain period (SIFS + ACK frame length) after transmitting a frame, it terminates the communication as it has failed. In this way, the end of one communication (also called a burst) in the IEEE802.11 system is always determined by the presence or absence of the reception of an ACK frame, except in special cases such as the transmission of a notification signal such as a beacon frame or the use of fragmentation to divide the transmission data.

[0033] When a terminal device determines that a received transmission frame is not addressed to the terminal device, the terminal device sets a network allocation vector (NAV) based on the length of the transmission frame described in the PHY header or the like. The terminal device does not attempt communication during the period set in the NAV. In other words, the terminal device performs the same operation as when the terminal device 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 described in the PHY header, the NAV is also set by a request to send (RTS) frame or a clear to send (CTS) frame introduced to solve the hidden terminal problem.

[0034] In contrast to DCF, in which each device performs carrier sensing and autonomously acquires the transmission right, in PCF, a control station called a Point Coordinator (PC) controls the transmission right of each device within the BSS. In general, a base station device becomes the PC and acquires the transmission right for terminal devices within the BSS.

[0035] The PCF communication period is divided into two periods: a contention free period (CFP) and a contention free period (CP). Contention period (CFP) is included. During the CP, communication is performed based on the DCF described above, and during the CFP, the PC controls the transmission right. The base station device, which is the PC, broadcasts a beacon frame in which the CFP period (CFP Max duration) and the like are described in the BSS prior to PCF communication. The beacon frame broadcast at the start of PCF transmission is transmitted using PIFS, without waiting for the CW. The terminal device that receives the beacon frame sets the CFP period described in the beacon frame to the NAV. After that, until the NAV elapses or a signal (e.g., a data frame including CF-end) that broadcasts the end of the CFP in the BSS is received, the terminal device can acquire the transmission right only when it receives a signal (e.g., a data frame including CF-poll) that signals the acquisition of the transmission right transmitted from the PC. During the CFP, no packet collision occurs within the same BSS, so each terminal device does not take the random backoff time used in DCF.

[0036] A wireless medium can be divided into a number of resource units (RUs). FIG. 4 is a schematic diagram showing an example of a division state of a wireless medium. For example, in resource division example 1, a wireless communication device can divide a frequency resource (subcarrier) which is a wireless medium into nine RUs. Similarly, in resource division example 2, a wireless communication device can divide a subcarrier which is a wireless medium into five RUs. Of course, the resource division example shown in FIG. 4 is only one example, and for example, a number of RUs can be configured with different numbers of subcarriers. In addition, the wireless medium divided into RUs can include not only frequency resources but also spatial resources. A wireless communication device (e.g., an AP) can transmit frames to a number of terminal devices (e.g., a number of STAs) simultaneously by placing frames addressed to different terminal devices in each RU. The AP can write information indicating the division state of the wireless medium (resource allocation information) in the PHY header of a frame transmitted by the own device as common control information. Furthermore, the AP can write information indicating the RU in which the frame addressed to each STA is placed (resource unit assignment information) as unique control information in the PHY header of the frame transmitted by the AP itself.

[0037] Furthermore, multiple terminal devices (e.g., multiple STAs) can transmit frames simultaneously by placing frames in the assigned RUs and transmitting them. After receiving a frame (Trigger frame: TF) containing trigger information transmitted from the AP, multiple STAs can transmit frames after waiting for a predetermined period of time. Each STA can grasp the RU assigned to itself based on the information written in the TF. Furthermore, each STA can acquire an RU by random access based on the TF.

[0038] The AP can simultaneously allocate multiple RUs to one STA. The multiple RUs can be configured with consecutive subcarriers or non-consecutive subcarriers. The AP can transmit one frame using the multiple RUs allocated to one STA, and can allocate multiple frames to different RUs for transmission. At least one of the multiple frames can be a frame including common control information for multiple terminal devices that transmit resource allocation information.

[0039] One STA can be assigned multiple RUs by the AP. The STA can transmit one frame using the assigned multiple RUs. Also, the STA can assign multiple frames to different RUs and transmit them using the assigned multiple RUs. The multiple frames can be frames of different frame types.

[0040] An AP can assign multiple AIDs to one STA. An AP can assign RUs to the multiple AIDs assigned to one STA. An AP can transmit different frames to the multiple AIDs assigned to one STA using the assigned RUs. The different frames can be frames of different frame types.

[0041] One STA can be assigned multiple AIDs by the AP. One STA can be assigned RUs for each of the multiple AIDs assigned to it. One STA recognizes all RUs assigned to the multiple AIDs assigned to its own device as RUs assigned to its own device, and can transmit one frame using the multiple assigned RUs. One STA can also transmit multiple frames using the multiple assigned RUs. At this time, the multiple frames can be transmitted with information indicating the AIDs associated with the assigned RUs written therein. The AP can transmit different frames for the multiple AIDs assigned to one STA using the assigned RUs. The different frames can be frames of different frame types.

[0042] Hereinafter, the base station device and the terminal device are collectively referred to as a wireless communication device or a communication device. Information exchanged when a wireless communication device communicates with another wireless communication device is also referred to as data. In other words, the wireless communication device includes the base station device and the terminal device.

[0043] The wireless communication device has either or both of a function for transmitting and receiving a PPDU. FIG. 1 is a diagram showing an example of a PPDU structure transmitted by a wireless communication device. A PPDU conforming to the IEEE802.11a / b / g standard is configured to include an L-STF, an L-LTF, an L-SIG, and a Data frame (MAC Frame, MAC frame, payload, data section, data, information bits, etc.). A PPDU conforming to the IEEE802.11n 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 IEEE802.11ac standard is configured to include an L-STF, an L-LTF, an L-SIG, a VHT-SIG-A, a VHT-STF, a VHT-LTF, a VHT-SIG-B, and a part or all of a MAC frame. The PPDU considered in the IEEE802.11ax standard is a configuration that includes some or all of the following: L-STF, L-LTF, L-SIG, RL-SIG in which L-SIG is repeated over time, HE-SIG-A, HE-STF, HE-LTF, HE-SIG-B, and Data frames.The PPDU considered in the IEEE802.11be standard is a configuration that includes some or all of the following: L-STF, L-LTF, L-SIG, RL-SIG, U-SIG, EHT-SIG, EHT-STF, HET-LTF, and Data frames.

[0044] The L-STF, L-LTF, and L-SIG enclosed by dotted lines in Fig. 1 are configurations commonly used in the IEEE 802.11 standard (hereinafter, L-STF, L-LTF, and L-SIG are also collectively referred to as L-header). For example, a wireless communication device compatible with the IEEE 802.11a / b / g standard can properly receive an L-header in a PPDU compatible with the IEEE 802.11n / ac standard. A wireless communication device compatible with the IEEE 802.11a / b / g standard can receive a PPDU compatible with the IEEE 802.11n / ac standard by regarding it as a PPDU compatible with the IEEE 802.11a / b / g standard.

[0045] However, wireless communication devices that comply with the IEEE 802.11a / b / g standards cannot demodulate the PPDU that complies with the IEEE 802.11n / ac standards, which follows the L-header, and therefore cannot demodulate information related to the transmitter address (TA: Transmitter Address), receiver address (RA: Receiver Address), or the Duration / ID field used to set the NAV.

[0046] IEEE 802.11 specifies a method of inserting Duration information into L-SIG as a method for wireless communication devices conforming to the IEEE 802.11a / b / g standards to appropriately set NAV (or to perform reception for a predetermined period of time). Information on the transmission rate in the L-SIG (RATE field, L-RATE field, L-RATE, L_DATARATE, L_DATARATE field) and information on the transmission period (LENGTH field, L-LENGTH field, L-LENGTH) are used by wireless communication devices conforming to the IEEE 802.11a / b / g standards to appropriately set NAV.

[0047] FIG. 2 is a diagram showing an example of a method of inserting Duration information into an L-SIG. In FIG. 2, a PPDU configuration corresponding to the IEEE802.11ac standard is shown as an example, but the PPDU configuration is not limited to this. A PPDU configuration corresponding to the IEEE802.11n standard and a PPDU configuration corresponding to the IEEE802.11ax standard may also be used. TXTIME includes information on the length of the PPDU, aPreambleLength includes information on the length of the preamble (L-STF+L-LTF), and aPLCPHeaderLength includes information on the length of the PLCP header (L-SIG). L_LENGTH includes a Signal Extension, which is a virtual period set to achieve compatibility with the IEEE802.11 standard, and an N related to L_RATE. opsIt is calculated based on aSymbolLength, which is information about the duration of one symbol (symbol, OFDM symbol, etc.), aPLCPServiceLength, which indicates the number of bits included in the PLCP Service field, and aPLCPConvolutionalTailLength, which indicates the number of tail bits of the convolutional code. The wireless communication device can calculate L_LENGTH and insert it into the L-SIG. The wireless communication device can also calculate L-SIG Duration. The L-SIG Duration indicates information about the duration obtained by adding up the duration of the PPDU including L_LENGTH and the duration of the Ack and SIFS that are expected to be transmitted from the destination wireless communication device in response to the PPDU.

[0048] FIG. 3 shows an example of L-SIG Duration in L-SIG TXOP Protection. DATA (frame, payload, data, etc.) is composed of a MAC frame and a part of the PLCP header or both. BA is Block Ack or Ack. PPDU is L-STF, L-LTF, L-SIG and may further include any one or more of DATA, BA, RTS, and CTS. In the example shown in FIG. 3, L-SIG TXOP Protection using RTS / CTS is shown, but CTS-to-Self may also be used. Here, MAC Duration is the period indicated by the value of the Duration / ID field. Also, the Initiator can transmit a CF_End frame to notify the end of the L-SIG TXOP Protection period.

[0049] Next, a method for identifying a BSS from a frame received by a wireless communication device will be described. In order for a wireless communication device to identify a BSS from a frame received, it is preferable for the wireless communication device transmitting a PPDU to insert information for identifying the BSS (BSS color, BSS identification information, a value unique to the BSS) into the PPDU. Information indicating the BSS color can be described in HE-SIG-A.

[0050] The wireless communication device can transmit the L-SIG multiple times (L-SIG Repetition). For example, the receiving wireless communication device receives the L-SIG transmitted multiple times using MRC (Maximum Ratio Combining), thereby improving the demodulation accuracy of the L-SIG. Furthermore, when the wireless communication device has correctly received the L-SIG using MRC, the wireless communication device can interpret the PPDU including the L-SIG as a PPDU that complies with the IEEE802.11ax 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, PLCP header, etc., defined by IEEE802.11) 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 destination address, a source address, and part or all of information related to the PPDU or 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] Considering large-capacity transmission such as ultra-high definition video transmission, communication in a high frequency band that can use a wide band is desired. In the high frequency band, path loss is large and the directivity of radio waves is strong, so if there is an obstacle between the communication devices, the radio waves will not reach the communication device easily. In this case, a route using reflection is effective. Therefore, the propagation environment can be improved by placing a propagation control device in a place where there is an obstruction. The propagation control device is assumed to be one that can control the reflection direction, such as an IRS (Intelligent Reflecting Surface). The propagation control device enables communication via the propagation control device even in an environment where the base station device and the terminal device cannot communicate directly due to the influence of an obstruction. FIG. 5 is an example of a communication system according to this embodiment. The communication system is composed of a base station device 1A, a terminal device 2A, a terminal device 2B, a terminal device 2C, and a propagation control device 3A. Note that the blocks indicated by diagonal lines indicate obstructions. In this case, the base station device 1A can directly communicate with the terminal device 2A, but cannot directly communicate with the terminal devices 2B and 2C. The base station device 1A can communicate with the terminal devices 2B and 2C via a propagation control device 3A. The propagation control device 3A can switch the reflection direction to a direction suitable for communication with the terminal device 2B or a direction suitable for communication with the terminal device 2C under the control of the base station device 1A.

[0054] 6 is a schematic block diagram showing an example of the configuration of a base station device in this embodiment. The base station device includes an upper layer processing unit (upper layer processing step) 101, a control unit (control step) 102, a transmission unit (transmission step) 103, a reception unit (reception step) 104, a transmission / reception antenna 105, and a carrier sense unit (carrier sense step) 106.

[0055] The upper layer processing unit 101 is connected to other networks and can notify traffic-related information to the control unit 102. The traffic-related information may be, for example, information addressed to other wireless communication devices, or control information included in a management frame or a control frame.

[0056] The control unit 102 generates a control signal for controlling the transmitting unit 103 and the receiving unit 104 based on information input from the upper layer processing unit 101. If transmission is required after carrier sensing, the control unit 102 controls the carrier sense unit 106 to perform carrier sensing and acquire channel occupancy time (or channel transmission permission time, transmission opportunity (TXOP)). After successful carrier sensing, the control unit 102 controls the transmitting unit 103 to transmit an RTS frame (resource reservation signal) or a transmission signal. The control unit 102 also generates control information for controlling the propagation control device 3A.

[0057] The transmitting unit 103 includes a physical layer frame generating unit (physical layer frame generating step) 1031 and a wireless transmitting unit (wireless transmitting step) 1032. The physical layer frame generating unit 1031 has a function of generating a physical layer frame (PPDU) based on transmission decision information notified from the carrier sense unit 106. The physical layer frame generating unit 1031 performs error correction coding, modulation, precoding filter multiplication, etc. on the transmission frame sent from the upper layer. The physical layer frame generating unit 1031 outputs the generated physical layer frame to the wireless transmitting unit 1032. The frame generated by the physical layer frame generating unit 1031 includes control information. The control information includes information indicating in which RU (here, RU includes both frequency resources and spatial resources) data addressed to each wireless communication device is arranged. In addition, the frame generated by the physical layer frame generating unit 1031 includes a trigger frame that instructs the wireless communication device, which is the destination terminal (target terminal device), to transmit the frame. The trigger frame includes information indicating the RU to be used when the wireless communication device instructed to transmit the frame transmits the frame. The wireless transmitting unit 1032 converts the physical layer frame generated by the physical layer frame generating unit 1031 into a signal in the radio frequency (RF) band to generate a radio frequency signal. The processing performed by the wireless transmitting unit 1032 includes digital-to-analog conversion, filtering, frequency conversion from the baseband band to the RF band, and the like. The transmitting unit 104 also has a function of generating a transmission signal including control information for controlling the propagation control device 3A.

[0058] The receiving unit 104 includes a wireless receiving unit (wireless receiving step) 1041 and a signal demodulation unit (signal demodulation step) 1042. The receiving unit 104 can output information on the received signal power of the received signal received by the transmitting / receiving antenna 105 and information on the received signal to the carrier sense unit 106. The wireless receiving unit 1041 has a function of converting a signal in a wireless frequency band received by the transmitting / receiving antenna 105 into a baseband signal and generating a physical layer signal (e.g., a physical layer frame). The processing performed by the wireless receiving unit 1041 includes frequency conversion processing from a wireless frequency band to a baseband band, filtering, and analog-to-digital conversion. The signal demodulation unit 1042 has a function of demodulating the physical layer signal generated by the wireless receiving unit 1041. The processing performed by the signal demodulation unit 1042 includes channel equalization, demapping, error correction decoding, and the like. The signal demodulation unit 1042 can extract, for example, information contained in the physical layer header, information contained in the MAC header, and information contained in the transmission frame from the physical layer signal. The signal demodulation unit 1042 can notify the upper layer processing unit 102 of the extracted information. The signal demodulation unit 1042 can extract any or all of the information contained in the physical layer header, information contained in the MAC header, and information contained in the transmission frame. The receiving unit 104 also receives a signal from the propagation control device 3A and notifies the upper layer processing unit 101. The receiving unit 104 may also receive a reference signal or infrared light for estimating or correcting a position from the propagation control device 3A.

[0059] The transmitting / receiving antenna 105 has a function of transmitting the radio frequency signal generated by the transmitting unit 103 into wireless space toward a communication device of a communication partner, and also has a function of receiving the radio frequency signal transmitted from the communication device.

[0060] The carrier sense unit 106 performs carrier sense using either or both of information on the power of the received signal received via the wireless resource and information on the received signal (including information after demodulation and decoding) notified from the receiving unit 104, and acquires the channel occupancy time (or channel transmission permission time, transmission right). The maximum value of the period during which the channel can be occupied (channel occupancy period) is also called MCOT (Maximum Channel Occupancy Time). MCOT also changes depending on the priority of the data. The priority of the data can be expressed by a priority class (channel access priority class) or a QoS (Quality of Service) class. Also, the maximum value of the random period required for carrier sense may change depending on the priority class. Note that the random period is the product of a random positive integer equal to or less than the contention window size (CWS) and a slot period (for example, 9 microseconds). Also, the random positive integer equal to or less than the contention window size is also called a counter in carrier sense. CWS may change depending on the priority class, transmission error rate, etc. Also, if the observed (detected) power is less than the energy detection threshold (or carrier sense level) for at least a predetermined period (e.g., 4 microseconds) in the slot period, the slot period is determined as idle. Otherwise, the slot period is determined as busy. When the slot is determined as idle, the counter value decreases, and when the counter value reaches 0, the carrier sense is determined as successful, and transmission determination information is notified to the transmitting unit 103. Note that the slot period may vary depending on the frequency band (frequency bandwidth, carrier frequency), and the slot period can be made shorter in higher frequency bands. Also, the period for determining whether the slot is idle / busy on a slot-by-slot basis may vary depending on the frequency band (frequency bandwidth, carrier frequency). In other words, the period during which the observed (detected) power is less than the energy detection threshold when determining whether the slot is idle can be made shorter in higher frequency bands.

[0061] 7 is a schematic block diagram showing an example of the configuration of a terminal device in this embodiment. The terminal device includes an upper layer processing unit (upper layer processing step) 201, a control unit (control step) 202, a transmission unit (transmission step) 203, a reception unit (reception step) 204, a transmission / reception antenna 205, and a carrier sense unit (carrier sense step) 206.

[0062] The upper layer processing unit 201 generates upper layer (Upper Layer, Higher Layer, IP Layer, TCP Layer, Session Layer, Presentation Layer, Application Layer, etc.) data. The upper layer unit 201 notifies the transmitting unit 202 of the generated transmission data. The upper layer unit 201 also has a function of notifying the upper layer of demodulated data demodulated by the receiving unit 203.

[0063] The control unit 202 generates a control signal for controlling the transmitting unit 203 and the receiving unit 204 based on information input from the upper layer processing unit 201. Furthermore, when transmission is necessary after carrier sensing, the control unit 202 controls the carrier sense unit 206 to perform carrier sensing and acquire channel occupancy time (or channel transmission permission time, transmission opportunity (TXOP)). Furthermore, after successful carrier sensing, the control unit 202 controls the transmitting unit 203 to transmit an RTS frame (resource reservation signal) or a transmission signal.

[0064] The transmitting unit 203 includes a physical layer frame generating unit (physical layer frame generating step) 2031 and a wireless transmitting unit (wireless transmitting step) 2032. The physical layer frame generating unit 2031 has a function of generating a physical layer frame (PPDU) based on transmission decision information notified from the carrier sense unit 206. The physical layer frame generating unit 2031 performs error correction coding, modulation, precoding filter multiplication, etc. on the transmission frame sent from the upper layer. The physical layer frame generating unit 2031 outputs the generated physical layer frame to the wireless transmitting unit 2032. The frame generated by the physical layer frame generating unit 2031 includes control information. The control information includes information indicating in which RU (here, RU includes both frequency resources and spatial resources) data addressed to each wireless communication device is arranged. In addition, the frame generated by the physical layer frame generating unit 2031 includes a trigger frame that instructs the wireless communication device, which is the destination terminal (target terminal device), to transmit the frame. The trigger frame includes information indicating the RU to be used when the wireless communication device instructed to transmit the frame transmits the frame. The wireless transmission unit 2032 converts the physical layer frame generated by the physical layer frame generation unit 2031 into a signal in the radio frequency (RF) band to generate a radio frequency signal. The processing performed by the wireless transmission unit 2032 includes digital-to-analog conversion, filtering, frequency conversion from the baseband band to the radio frequency band, and the like.

[0065] The receiving unit 204 includes a wireless receiving unit (wireless receiving step) 2041 and a signal demodulation unit (signal demodulation step) 2042. The receiving unit 204 can output information on the received signal power of the received signal received by the transmitting / receiving antenna 205 and information on the received signal to the carrier sense unit 206. The wireless receiving unit 2041 has a function of converting a wireless frequency band signal received by the transmitting / receiving antenna 205 into a baseband signal and generating a physical layer signal (e.g., a physical layer frame). The processing performed by the wireless receiving unit 2041 includes frequency conversion processing from the wireless frequency band to the baseband band, filtering, and analog-to-digital conversion. The signal demodulation unit 2042 has a function of demodulating the physical layer signal generated by the wireless receiving unit 2041. The processing performed by the signal demodulation unit 2042 includes channel equalization, demapping, error correction decoding, and the like. The signal demodulation unit 2042 can extract, for example, information contained in the physical layer header, information contained in the MAC header, and information contained in the transmission frame from the physical layer signal. The signal demodulation unit 2042 can notify the extracted information to the upper layer processing unit 202. The signal demodulation unit 2042 can extract any or all of the information contained in the physical layer header, information contained in the MAC header, and information contained in the transmission frame.

[0066] The transmitting / receiving antenna 205 has a function of transmitting the radio frequency signal generated by the transmitting unit 203 into wireless space toward a communication device of a communication partner, and also has a function of receiving the radio frequency signal transmitted from the communication device.

[0067] The carrier sense unit 206 performs carrier sense using either or both of information regarding the received signal power received via wireless resources and information regarding the received signal (including information after demodulation and decoding) notified by the receiving unit 204, and acquires channel occupancy time (or channel transmission permission time, transmission right).

[0068] The communication device of the present embodiment can set a NAV (Network Allocation Vector, transmission prohibition period) in the communication devices around the communication device only for the period by describing information indicating the period during which the communication device uses the wireless medium in the PHY header or MAC header of the frame to be transmitted. For example, the communication device can describe information indicating the period in the Duration / ID field or Length field of the frame to be transmitted. The communication device can also describe the period during which the wireless medium is secured in a predetermined field of the PHY header or MAC header. The NAV period set in the wireless communication devices around the communication device is called the TXOP period (or simply TXOP) acquired by the communication device. The communication device that has acquired the TXOP is called a TXOP acquirer (TXOP holder). The frame type of the frame transmitted by the communication device to acquire the TXOP is not limited to any particular type, and may be a control frame (for example, an RTS frame or a CTS-to-self frame) or a data frame. The communication device can also describe information indicating the TXOP acquirer in a predetermined field of the PHY header or MAC header. The information indicating the XOP acquirer can be a MAC address, an AID, or a partial AID.

[0069] A communication device that is a TXOP holder can transmit frames to wireless communication devices other than the own device during the TXOP. For example, if a base station device is a TXOP holder, it can transmit frames to a terminal device within the TXOP period. Furthermore, the base station device can instruct the terminal device to transmit a frame to the base station device or to a communication device other than the base station device within the TXOP period. The base station device can transmit a trigger frame including information instructing the terminal device to transmit a frame to the base station device within the TXOP period. Note that the terminal device can also become a TXOP holder.

[0070] A communication device may reserve a TXOP for all communication bands over which frames may be transmitted (e.g., Operation bandwidth), or may reserve a TXOP for a specific communication band, such as a communication band over which frames will actually be transmitted (e.g., Transmission bandwidth).

[0071] The communication device that instructs a communication device to transmit a frame during the period of the TXOP acquired by the communication device is not necessarily limited to the communication device connected to the communication device itself. For example, the communication device can instruct a communication device not connected to the communication device itself to transmit a frame in order to make the communication device in the vicinity of the communication device transmit a management frame such as a Reassociation frame or a control frame such as an RTS / CTS frame.

[0072] In high frequency bands, beamforming is essential to compensate for large path loss. In particular, when a signal cannot reach a target without beamforming, the communication device must know the preferred beam direction. For example, if the base station device knows the position (coordinates) of the terminal device in advance and the base station device and the terminal device are within line of sight, good quality communication can be achieved by directing the beam toward the terminal device. When the base station device does not know the position of the terminal device, beam sweeping is effective for finding the preferred beam direction. Beam sweeping uses a training signal. The training signal includes a synchronization signal and a reference signal. FIG. 8 shows an example of beam sweeping using downlink signals in the base station device 1A and the terminal device 2A. FIG. 8(a) is an example of a transmission beam sweep, and FIG. 8(b) is an example of a reception beam sweep. The base station device 1A transmits training signals 801 beamformed in different beam directions in sequence at different times (symbols, slots), and the terminal device 2A receives them in one reception beam direction 802. If an index (or identifier) ​​is given to the training signal for the beam direction, the terminal device 2A can feed back the identifier of the training signal with the suitable reception power / reception quality to the base station device 1A, and the base station device 1A can know the suitable beam direction. On the other hand, if the base station device 1A transmits in one transmission beam direction 803 and the terminal device measures the reception power / reception quality in multiple reception beam directions 804 in sequence by changing the time (symbol, slot), the base station device 1A can know the suitable reception beam direction. Furthermore, if the transmission beam sweep and the reception beam sweep are repeated, the accuracy of the beam sweep is improved, but the time required for the beam sweep is longer, so there is a trade-off between accuracy and delay time. For the uplink beam sweep, the base station device 1A and the terminal device 2A in FIG. 8 can be replaced and the uplink signal can be used. Furthermore, if channel reciprocity of TDD (Time Division Duplex) holds, the preferred transmitting beam direction and receiving beam direction of the base station device can be the same, and the preferred transmitting beam direction and receiving beam direction of the terminal device can be the same, so the time and number of beam sweeps can be reduced.

[0073] Since the propagation control device can control the reflection direction, it is necessary to know the reflection direction that is suitable for the base station device / terminal device. Assuming that the positions of the base station device and the propagation control device are fixed and do not move, the beam direction from the base station device to the propagation control device may be fixed. Also, since the base station device controls the propagation control device, it is assumed that the position or direction of the propagation control device is known by some method. FIG. 9 is an example of reflection direction sweeping using a downlink signal in the base station device 1A, terminal device 2C, and propagation control device 3A. A fixed transmission beam direction 901 is transmitted from the base station device 1A to the propagation control device 3A. The base station device 1A controls the propagation control device 3A so that the reflection direction is changed in sequence by time (symbol, slot). The propagation control device 3A reflects the training signal transmitted by the base station device 1A to multiple reflection directions 902 under the control of the base station device 1A. If an index (or identifier) ​​is assigned to the reflection direction of the training signal, the terminal device 2C can measure the reception power / reception quality of multiple reflected signals received and feed back the identifier of a suitable training signal to the base station device 1A, allowing the base station device 2A to know the suitable reflection direction of the propagation control device 3A. Note that since a change in the carrier frequency may cause a change in the suitable reflection direction for the terminal device, the sweeping of the reflection direction may be performed in multiple frequency bands.

[0074] As described above, the base station device transmits a training signal in a beam direction or a reflection direction associated with an index (or an identifier), and the terminal device searches for a suitable beam direction. In the case of a propagation control device, the base station device must be able to distinguish between beam directions and reflection directions by indexes. Therefore, the base station device must transmit training signals for all patterns of beam directions and reflection directions, and by giving the training signals an index for all candidates, the beam direction and reflection direction can be distinguished. For example, the index of the training signal is associated with the time resource (symbol, slot) to be transmitted or the index of the time resource. The time resource can be expressed as a difference from a reference timing such as the beginning of a frame. For example, it is assumed that the base station device has four beam directions and the propagation control device has three reflection directions. In the case of one propagation control device, the beam direction and reflection direction can be distinguished with six indexes. For example, if beam direction 0 is the direction of the propagation control device, the base station device transmits a training signal three times in beam direction 0, and transmits a training signal once each in beam directions 1 to 3. The index of the training signal may be associated with the beam direction of the base station device. In an example where the base station device has four beam directions, the index is set to 0 to 3. If there are 12 time resources capable of transmitting a training signal, the beam direction and the reflection direction can be specified. However, the index of the time resource is set to 0 to 11. In this case, the remainder when the index of the time resource is divided by 4 becomes the index of the beam direction. Since there are 12 time resources, the base station device can use the same index of the beam direction three times. The beam direction associated with the propagation control device transmits the training signal in a different reflection direction each time, and is used to search for the reflection direction. In this example, the index of the reflection direction is the quotient of the time resource divided by 4. Note that the beam direction not associated with the propagation control device can be combined to improve the accuracy of the transmission beam sweep or to use for the reception beam sweep. Also, whether or not the beam direction (or index) is associated with the propagation control device is notified to the terminal device from the base station device.Also, the base station device can transmit a training signal according to the purpose. If the purpose is a transmission beam sweep, the base station device changes the beam direction for each time resource and transmits the training signal. If the purpose is a reception beam sweep, the base station device transmits the training signal in the same beam direction for each time resource. If the purpose is a reflection direction sweep, the base station device transmits the training signal in the same beam direction for each time resource, but controls the propagation control device so that the reflection direction is different for each time resource. The base station device can notify the terminal device of the purpose of transmitting the training signal. At this time, the terminal device receives the training signal according to the purpose notified from the base station device. Note that, if the purpose is a transmission beam sweep and a reflection direction sweep, the terminal device transmits a suitable resource index to the base station device. If the purpose is a reception beam sweep, feedback to the base station device is not required. Also, the base station device can notify the terminal device of whether the transmission beam direction is different for each time resource for transmitting the training signal. If the terminal device receives information indicating that the transmission beam direction is different for each time resource, it determines that it is a transmission beam sweep and receives the training signal. When the terminal device receives information indicating that the transmission beam direction is the same for each time resource, the terminal device cannot determine whether it is a reception beam sweep or a reflection direction sweep. For example, the base station device transmits information indicating whether feedback (report) of a resource index is required to the terminal device. When the terminal device receives information indicating that the transmission beam direction is the same for each time resource and feedback is requested, the terminal device determines that it is a reflection direction sweep and transmits a suitable resource index to the base station device. When the terminal device receives information indicating that the transmission beam direction is the same for each time resource and feedback is not requested, the terminal device determines that it is a reception beam sweep. Note that although the base station device transmits information indicating that the transmission beam direction is different for each time resource, the base station device may transmit a training signal using the same beam direction to control the reflection direction of the propagation control device.

[0075] As described above, in an unlicensed band, a signal is transmitted after acquiring a wireless medium. When a propagation control device is present, the base station device cannot communicate with a terminal device via the propagation control device unless it controls the reflection direction. This means that the base station device can only grasp the communication status of the terminal device whose reflection direction is facing when the base station device performs carrier sense. An example will be described with reference to FIG. 5. Assume that the reflection direction of the propagation control device 3A is set to the terminal device 2B. For example, the base station device 1A transmits an RTS frame with the terminal device 2A as the destination to acquire a TXOP period. The base station device 1A transmits a transmission signal to the terminal device 2A. At this time, the base station device 1A transmits an RTS frame to the terminal device 2B to which the reflection direction is set and a transmission inhibition period is set, but the base station device 1A does not transmit an RTS frame to the terminal device 2C to which the reflection direction is not facing, so no transmission inhibition section is set. At this time, if the base station device 1A sets the reflection direction of the propagation control device 3A to the communication device 2C, there is a possibility that the communication device 2C will transmit a signal, which may collide with the uplink signal of the terminal device 2A. To avoid this, when the base station device 1A acquires the wireless medium, it is possible not to control the reflection direction of the propagation control device 3A within the TXOP period.

[0076] When the base station device 1A transmits an RTS frame to the terminal device 2A by beamforming, there is a possibility that the RTS frame will not be received by communication devices other than the terminal device 2A. Therefore, if the base station device 1A transmits the RTS frame multiple times by changing the beam direction, each terminal device can receive the RTS frame. Furthermore, when the propagation control device 3A is not controlled, the base station device 1A transmits the RTS frame once in each beam direction. Furthermore, when the propagation control device 3A is controlled, the base station device 1A transmits the RTS frame multiple times in the beam direction corresponding to the propagation control device 3A.

[0077] When the base station device 1A communicates with a terminal device via the propagation control device 3A, the base station device 1A controls the propagation control device 3A within the TXOP period, and can communicate with multiple terminal devices. When the base station device 1A transmits an RTS frame addressed to the terminal device 2B, the terminal device 2A receives the RTS frame and a transmission inhibition period is set. The terminal device 2C does not receive the RTS frame. If the terminal device 2B transmits a CTS frame after receiving the RTS frame, it can set a transmission inhibition period for the terminal device 2C.

[0078] Also, the base station device 1A can transmit an RTS frame with the propagation control device 3A as the destination. In this case, the terminal device 2A sets a transmission inhibition period, but the terminal devices 2B and 2C that pass through the propagation control device 3A do not set a transmission inhibition period. The destination of the RTS frame does not have to indicate the propagation control device 3A, and it is sufficient if it is an identifier common to the terminal devices 2B and 2C. Instead of the common identifier, information directly indicating the terminal devices 2B and 2C can also be written in the RTS frame. As information directly indicating the terminal device 2B and the terminal device 2C, the AID can be directly written, or a Group ID indicating the AID of the terminal device 2B and the terminal device 2C can also be written.

[0079] The propagation control device 3A may be capable of setting a communication mode and an observation mode. The communication mode is set when communicating with a terminal device individually, such as when transmitting data. The observation mode is set when the base station device 1A acquires a wireless medium, such as when sensing a carrier or transmitting an RTS frame. The observation mode is also set when the base station device 1A transmits a beacon frame, a control signal, or the like to all terminal devices passing through the propagation control device 3A. When the base station device 1A sets the propagation control device 3A to the communication mode, it can control the reflection direction of the propagation control device 3A. When the base station device 1A sets the propagation control device 3A to the observation mode, the propagation control device 3A fixes the reflection direction to a preset width and direction, such as 90 degrees or 180 degrees. In the observation mode, the base station device 1A can also control the propagation control device 3A to scatter instead of reflect.

[0080] In addition, the base station device 1A can set the maximum period of the TXOP that can be acquired depending on the presence or absence of the propagation control device 3A. For example, the base station device 1A can set the TXOP that can be acquired when the propagation control device 3A exists in the BSS to be equal to or less than the TXOP that can be acquired when the propagation control device 3A does not exist.

[0081] The frequency bands used by the devices (base station devices, terminal devices) according to this embodiment are not limited to the licensed bands and unlicensed bands described above. The frequency bands covered by this embodiment include frequency bands called white bands (white spaces) that are not actually used for the purpose of preventing interference between frequencies even though permission for use for specific services is given by a country or region (for example, frequency bands that are allocated for television broadcasting but are not used in some regions), and shared frequency bands (license-sharing bands) that have been exclusively allocated to specific operators but are expected to be shared by multiple operators in the future.

[0082] The program that runs on the device according to the present invention may be a program that controls a Central Processing Unit (CPU) or the like to make a computer function so as to realize the functions of the embodiments according to the present invention. The program or information handled by the program is temporarily stored in a volatile memory such as a Random Access Memory (RAM), a non-volatile memory such as a flash memory, a Hard Disk Drive (HDD), or other storage device system.

[0083] A program for implementing the functions of the embodiments of the present invention may be recorded on a computer-readable recording medium. The program may be implemented by loading the program recorded on the recording medium into a computer system and executing it. The term "computer system" as used herein refers to a computer system built into an apparatus, and includes hardware such as an operating system and peripheral devices. The term "computer-readable recording medium" may refer to a semiconductor recording medium, an optical recording medium, a magnetic recording medium, a medium that dynamically holds a program for a short period of time, or any other computer-readable recording medium.

[0084] In addition, each functional block or feature of the device used in the above-mentioned embodiment may be implemented or performed by an electric circuit, for example, an integrated circuit or a plurality of integrated circuits. The electric circuit designed to perform the functions described herein may include a general-purpose processor, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field programmable gate array (FPGA), or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or a combination thereof. The general-purpose processor may be a microprocessor, or a conventional processor, controller, microcontroller, or state machine. The electric circuit described above may be composed of a digital circuit or an analog circuit. In addition, when a technology for integrated circuitization that replaces current integrated circuits appears due to the progress of semiconductor technology, one or more aspects of the present invention may use a new integrated circuit according to that technology.

[0085] The present invention is not limited to the above-described embodiment. In the embodiment, an example of a device is described, but the present invention is not limited to this, and can be applied to stationary or non-movable electronic devices installed indoors or outdoors, such as terminal devices or communication devices of AV equipment, kitchen equipment, cleaning / washing equipment, air conditioners, office equipment, vending machines, and other household appliances.

[0086] Although the embodiments of the present invention have been described above in detail with reference to the drawings, the specific configuration is not limited to this embodiment, and design changes and the like within the scope of the gist of the present invention are also included. Furthermore, the present invention can be modified in various ways within the scope of the claims, and embodiments obtained by appropriately combining the technical means disclosed in different embodiments are also included in the technical scope of the present invention. Furthermore, configurations in which elements described in the above embodiments are replaced with elements that have the same effect are also included. [Industrial Applicability]

[0087] The present invention is suitable for use in a base station device and a communication method. [Explanation of symbols]

[0088] 1A base station equipment 2A, 2B, 2C Terminal Equipment 3A Propagation Control Device 101 Upper layer processing unit 102 Control section 103 Transmitter 104 Receiving unit 105 Transmitting and Receiving Antenna 106 Carrier Sense Department 1031 Physical layer frame generator 1032 Radio transmitter 1041 Radio receiver 1042 Signal demodulation section 201 Upper layer processing unit 202 Control section 203 Transmitter 204 Receiving section 205 Transmitting and Receiving Antenna 206 Career Sense Department 2031 Physical layer frame generator 2032 Radio transmitter 2041 Radio receiver 2042 Signal demodulation section 801, 803, 901 Transmit beam direction 802, 804 Receiving beam direction 902 Reflection direction

Claims

1. A base station device that communicates with a terminal device, A control unit that controls a reflection direction of the propagation control device; a transmission unit that transmits a control frame to the terminal device; Equipped with The control frame is used to acquire a transmission opportunity (TXOP), During the period in which the TXOP is acquired, the reflection direction of the propagation control device at the time of transmitting the control frame is used. Base station equipment.

2. The terminal devices are classified into a first terminal device that communicates by controlling the propagation control device and a second terminal device that communicates without controlling the propagation control device; When there are a plurality of the first terminal devices, When the control frame is transmitted to the propagation control device as a destination, the reflection direction is controlled within a period during which the TXOP is acquired. The base station device according to claim 1 .

3. The control frame is transmitted in a predetermined beam direction when the first terminal device is the destination, and is transmitted in a plurality of beam directions when the second terminal device is the destination. The base station device according to claim 2 .

4. A communication method in a base station device that communicates with a terminal device, comprising: controlling a reflection direction of a propagation control device; transmitting a control frame addressed to the terminal device; having The control frame is used to acquire a transmission opportunity (TXOP), During the period in which the TXOP is acquired by the control frame, the reflection direction of the propagation control device at the time of transmitting the frame is used. Communication methods.

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