Terminal device, base station device, and communication method

Abstract

A terminal device includes a transmission unit and a reception unit, the reception unit receives SR link information including information of an allowed maximum transmission power, the transmission unit transmits a transmission frame when the reception power received by the reception unit is less than or equal to a threshold value, and the transmission unit transmits the SR link information to the reception unit when the transmission frame is transmitted. The transmission power is set to be equal to or less than the allowed maximum transmission power, when the threshold value is equal to or less than a first value, the allowed maximum transmission power is set to be a value indicated by the information of the allowed maximum transmission power, and when the threshold value is greater than the first value and equal to or less than a second value, the allowed maximum transmission power is set to be a value indicated by the information of the allowed maximum transmission power. The allowed maximum transmission power is set to a value obtained on the basis of a threshold and a value indicated by the information on the allowed maximum transmission power.

Description

Technical Field

[0001] The present invention relates to a terminal device, a base station device, and a communication method. This application claims priority from Japanese Patent Application No. 2022-157608 filed in Japan on September 30, 2022, the contents of which are incorporated herein by reference. Background Art

[0002] The IEEE (The Institute of Electrical and Electronics Engineers Inc.) is continuously working on updating the specifications of IEEE802.11, the wireless LAN standard specification, in order to achieve higher speeds and more efficient frequency utilization for wireless LAN (Local Area Network) communications. In wireless LAN, wireless communications can be performed using unlicensed frequency bands that can be used without a license (authorization) from a country or region. For personal use in homes, for example, wireless LAN access point functions are included in line terminal devices for connecting to WAN (Wide Area Network) lines such as the Internet, or wireless LAN access point devices (AP: Access Point) are connected to line terminal devices, making Internet access from within the home wireless. That is, wireless LAN station devices (STAs) such as smartphones and PCs can connect to the wireless LAN access point device to access the Internet.

[0003] In February 2021, the IEEE 802.11ax specification was completed, and wireless LAN devices that meet the specification, as well as smartphones and PCs (Personal Computers) equipped with such wireless LAN devices, were launched as Wi-Fi 6 (a registered trademark for IEEE 802.11ax standard products certified by the Wi-Fi Alliance). Currently, standardization activities for IEEE 802.11be have begun as a successor standard to IEEE 802.11ax. With the rapid spread of wireless LAN devices, research has been conducted in the IEEE 802.11be standardization to further improve the throughput per user in an overcrowded configuration environment of wireless LAN devices.

[0004] In the standards after IEEE802.11n, a frame aggregation mechanism has been introduced as a technology for increasing throughput by reducing overhead. Frame aggregation is roughly divided into A-MSDU (Aggregated MAC Service Data Unit) and A-MPDU (Aggregated MAC Protocol Data Unit). Frame aggregation can send a lot of data at once, improving transmission efficiency, but it also increases the possibility of transmission errors. Therefore, in the standards after IEEE802.11ax, as a key element technology for increasing throughput, in addition to improving transmission efficiency achieved by frame aggregation, it is also hoped that efficient error control for each MPDU will be introduced. In addition, a mechanism for increasing OFDMA (Orthogonal Frequency Division Multiple Access) and TXOP (Transmit Opportunity) called inter-BSS spatial reuse is adopted, hoping to improve transmission efficiency. Summary of the Invention Problems to be solved by the invention

[0005] With the increasing popularity of wireless LAN devices, the areas where wireless LAN devices are used in cities have expanded, and two wireless LAN devices are used in the surrounding areas depending on the location. When increasing business in such an overcrowded environment, when wireless medium access based on CSMA (Carrier Sense Multiple Access) used in the IEEE802.11 specification is performed, the time required to ensure TXOP is reduced due to the occurrence of conflicts and the generation of exposed terminals, thereby reducing transmission efficiency. The IEEE802.11ax standard specification adopts inter-BSS spatial reuse technology to partially alleviate this problem, but it is not enough.

[0006] One solution of the present invention is completed in view of such a situation, and discloses a communication device and a communication method that can increase the opportunity to ensure TXOP by implementing spatial reuse operation within the same wireless system (BSS), thereby improving transmission efficiency and reducing latency. Solutions for solving problems

[0007] A communication device and a communication method according to one aspect of the present invention for solving the above-mentioned problems are as follows.

[0008] (1) That is, a wireless terminal device according to one embodiment of the present invention includes a transmitting unit and a receiving unit, the receiving unit receiving SR (Scheduling Request) link information including information on an allowed maximum transmission power, and when the reception power received by the receiving unit is less than or equal to a threshold value, the transmitting unit transmits a transmission frame. When transmitting the transmission frame, the transmission power is set to be less than or equal to the allowed maximum transmission power, and when the threshold value is less than or equal to a first value, the allowed maximum transmission power is set to a value indicated by the information on the allowed maximum transmission power, and when the threshold value is greater than the first value and less than or equal to a second value, the allowed maximum transmission power is set to a value obtained based on the value indicated by the information on the allowed maximum transmission power and the threshold value.

[0009] (2) Furthermore, a base station apparatus according to one aspect of the present invention includes a transmission unit that transmits SR link information including information on permitted maximum transmission power.

[0010] (3) In addition, a communication method of an embodiment of the present invention is a communication method in a terminal device, wherein SR link information including information on the maximum allowable transmission power is received; a transmission frame is transmitted when the received power is less than or equal to a threshold; when the transmission frame is transmitted, the transmission power is set to be less than or equal to the maximum allowable transmission power; when the threshold is less than or equal to a first value, the maximum allowable transmission power is set to a value represented by the information on the maximum allowable transmission power; and when the threshold is greater than the first value and less than or equal to a second value, the maximum allowable transmission power is set to a value obtained based on the value represented by the information on the maximum allowable transmission power and the threshold. Effects of the Invention

[0011] According to one aspect of the present invention, it is possible to contribute to improvement of communication efficiency in communications using a wireless communication device compliant with the IEEE802.11 standard. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 This is a schematic diagram showing an example of division of wireless resources according to one aspect of the present invention. Figure 2 This is a diagram showing an example of a frame structure according to one embodiment of the present invention. Figure 3 This is a diagram showing an example of a frame structure according to one embodiment of the present invention. Figure 4 This is a diagram showing an example of communication according to one embodiment of the present invention. Figure 5 This is a diagram showing a configuration example of a communication system according to one embodiment of the present invention. Figure 6This is a block diagram showing a configuration example of a wireless communication device according to one embodiment of the present invention. Figure 7 This is a block diagram showing a configuration example of a wireless communication device according to one embodiment of the present invention. Figure 8 This is a schematic diagram of wireless frame transmission according to one embodiment of the present invention. Figure 9 This is a diagram showing an example of the relationship between the threshold value of the reception power detection level for channel access and the maximum allowable transmission power according to one embodiment of the present invention. Figure 10 This is a diagram showing an example of the relationship between the threshold value of the reception power detection level for channel access and the maximum allowable transmission power according to one embodiment of the present invention. Figure 11 This is a diagram showing an example of the relationship between the threshold value of the reception power detection level for channel access and the maximum allowable transmission power according to one embodiment of the present invention. DETAILED DESCRIPTION

[0013] The communication system of this embodiment includes an access point device (also called a base station device) and multiple station devices (also called terminal devices or wireless terminal devices). Furthermore, a communication system or network composed of access point devices and station devices is referred to as a basic service set (BSS: Basic Service Set, Management Area, Cell). Furthermore, the station device of this embodiment may have the functionality of an access point device. Similarly, the access point device of this embodiment may have the functionality of a station device (also called a terminal device). Therefore, hereinafter, when simply referred to as a communication device or a wireless communication device, the communication device or the wireless communication device may refer to both a station device and an access point device. Furthermore, an access point device may also communicate with other access point devices.

[0014] The base station device and the terminal device within the BSS are configured to communicate based on CSMA / CA (Carrier sense multiple access with collision avoidance). In this embodiment, the infrastructure mode in which the base station device communicates with multiple terminal devices is the target, but the method of this embodiment can also be implemented in an ad hoc mode in which terminal devices communicate directly with each other. In ad hoc mode, the terminal device forms the BSS instead of the base station device. The BSS in the ad hoc mode is also referred to as an IBSS (Independent Basic Service Set). Hereinafter, the terminal device forming the IBSS in the ad hoc mode may also be regarded as a base station device. The method of this embodiment can also be implemented in P2P (Peer to Peer) communication in which terminal devices communicate directly with each other. One of the implementation methods of P2P communication is TDLS (Tunneled Direct Link Setup). In TDLS, the services flowing between terminal devices connected to the base station device are directly sent and received between the terminal devices without passing through the base station device. The method of this embodiment can also be implemented in Wi-Fi Direct (Wi-Fi Direct, registered trademark). In Wi-Fi Direct, a terminal device forms a group instead of a base station device. Hereinafter, a terminal device that is a group owner of a Wi-Fi Direct group may also be referred to as a base station device.

[0015] In the IEEE 802.11 system, each device can transmit multiple frame types using a common frame format. Transmission frames are defined by the physical (PHY), medium access control (MAC), and logical link control (LLC) layers. The physical layer is also referred to as the PHY layer, and the MAC layer is also referred to as the MAC layer.

[0016] The transmission frame of the PHY layer is called a physical protocol data unit (PPDU). The PPDU consists of a physical layer header (PHY header), which includes header information for signal processing at the physical layer, and a physical service data unit (PSDU), which is a data unit processed at the physical layer. The PSDU can be composed of an aggregated MPDU (A-MPDU), which is an aggregation of multiple MAC protocol data units (MPDUs), which serve as the retransmission unit for wireless transmission.

[0017] The PHY header includes reference signals such as the short training field (STF) used for signal detection / synchronization, the long training field (LTF) used to obtain channel information for data demodulation, and control signals such as the signal (SIG) containing control information for data demodulation. Furthermore, according to the corresponding standards, STF is 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). Similarly, LTF and SIG are classified into L-LTF, HT-LTF, VHT-LTF, HE-LTF, L-SIG, HT-SIG, VHT-SIG, HE-SIG, and EHT-SIG. The VHT-SIG is further categorized into VHT-SIG-A1, VHT-SIG-A2, and VHT-SIG-B. Similarly, the HE-SIG is categorized into HE-SIG-A1 to -4 and HE-SIG-B. Furthermore, a Universal Signal (U-SIG) field may be included, assuming a technology update within the same standard and including additional control information.

[0018] Furthermore, the PHY header may include information identifying the BSS (hereinafter referred to as BSS identification information) that is the source of the transmitted frame. Examples of BSS identification information include the BSS's SSID (Service Set Identifier) ​​and the MAC address of the BSS's base station. Furthermore, BSS identification information may include BSS-specific values ​​other than the SSID and MAC address (e.g., BSS color).

[0019] The PPDU is modulated according to the corresponding standard. For example, if it is the IEEE 802.11n standard, it is modulated into an Orthogonal Frequency Division Multiplexing (OFDM) signal.

[0020] An MPDU consists of a MAC header (MAC header), which contains header information used for signal processing at the MAC layer; a MAC service data unit (MSDU) or frame body, which is a data unit processed at the MAC layer; and a frame check sequence (FCS) that checks for errors in the frame. Multiple MSDUs can also be aggregated into an aggregated MSDU (A-MSDU).

[0021] Frame types transmitted at the MAC layer are categorized into three main types: management frames, which manage the connection status between devices; control frames, which manage the communication status between devices; and data frames, which contain the actual transmitted data. Each of these frames is further categorized into various subframe types. Control frames include Acknowledge (Ack) frames, Request to Send (RTS) frames, and Clear to Send (CTS) frames. Management frames include Beacon (Beacon) frames, Probe Request (Probe Request) frames, Probe Response (Probe Response) frames, Authentication (Authentication) frames, Association Request (Association Request) frames, and Association Response (Association Response) frames. Data frames include Data (Data) frames and Contention-Free Poll (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 in the MAC header.

[0022] It should be noted that Ack can also include Block Ack. Block Ack can implement reception completion notification for multiple MPDUs. In addition, Ack can also include Multi-STA Block Ack (M-BA) containing reception completion notification for multiple communication devices.

[0023] The beacon frame includes a field (Field) that records the period for sending beacons (Beacon interval) and the SSID. The base station device can periodically broadcast beacon frames within the BSS, and the terminal device can grasp the base station devices around the terminal device by receiving the beacon frames. The situation in which the terminal device grasps the base station device based on the beacon frame broadcast by the base station device is called passive scanning. On the other hand, the situation in which the terminal device detects the base station device by broadcasting a probe request frame within the BSS is called active scanning. The base station device can send a probe response frame as a response to the probe request frame. The content of the probe response frame is the same as that of the beacon frame.

[0024] After identifying the base station device, the terminal device performs connection processing on the base station device. The connection processing is classified into an authentication process and an association process. The terminal device sends an authentication frame (authentication request) to the base station device to which it wishes to connect. When receiving the authentication frame, the base station device sends an authentication frame (authentication response) to the terminal device including a status code (status code) indicating whether the terminal device can be authenticated. The terminal device can determine whether the device itself is allowed to be authenticated by the base station device by reading the status code recorded in the authentication frame. It should be noted that the base station device and the terminal device can exchange authentication frames multiple times.

[0025] Following the authentication process, the terminal device sends a connection request frame to the base station device to initiate the connection process. Upon receiving the connection request frame, the base station device determines whether to allow the terminal device to connect and sends a connection response frame to notify the base station of this decision. The connection response frame contains a status code indicating whether the connection can be made and an association identifier (AID) used to identify the terminal device. The base station device can manage multiple terminal devices by assigning different AIDs to each terminal device that issues connection permission.

[0026] After the base station and terminal devices complete the connection process, they actually transmit data. The IEEE 802.11 system defines a distributed coordination function (DCF), a point coordination function (PCF), and extended functions such as enhanced distributed channel access (EDCA) and a hybrid coordination function (HCF). The following example uses the case where a base station sends a signal to a terminal device via the DCF, but the same applies to cases where a terminal device sends a signal to a base station via the DCF.

[0027] In DCF, the base station device and the terminal device perform carrier sense (CS) to confirm the usage status of the wireless channel around the device itself before communicating. For example, when the base station device, which is a transmitting station, receives a signal higher than the predetermined clear channel assessment level (CCA level: Clear channel assessment level) through the wireless channel, it postpones the transmission of the transmission frame on the wireless channel. Hereinafter, in the wireless channel, the state in which a signal above the CCA level is detected is referred to as a busy state, and the state in which a signal above the CCA level is not detected is referred to as an idle state. In this way, the CS performed by each device based on the power (received power level) of the actual received signal is called physical carrier sense (physical CS). It should be noted that the CCA level is also referred to as a carrier sense level (CS level) or a CCA threshold (CCA threshold: CCAT). It should be noted that when the base station device and the terminal device detect a signal above the CCA level, they enter an action of demodulating at least the signal of the PHY layer.

[0028] The base station performs carrier sensing at an interframe space (IFS) corresponding to the type of transmission frame to be sent, and determines whether the wireless channel is busy or idle. The period during which the base station performs carrier sensing varies depending on the frame type and subframe type of the transmission frame to be transmitted by the base station. The IEEE 802.11 system defines multiple IFSs with different time periods, including the Short Interframe Space (SIFS) for transmission frames with the highest priority, the Polling Interframe Space (PCF IFS) for transmission frames with higher priority, and the Distributed Control Interframe Space (DCF IFS) for transmission frames with the lowest priority. When the base station transmits data frames using the DCF, the base station uses the DIFS.

[0029] After waiting for DIFS, the base station device further waits for a random backoff time to prevent frame collisions. IEEE 802.11 systems use a random backoff time called a contention window (CW). CSMA / CA assumes that a transmit frame sent by a transmitting station can be received by a receiving station without interference from other transmitting stations. Therefore, if transmitting stations send transmit frames at the same time, a frame collision occurs, preventing the receiving station from accurately receiving the frame. Therefore, each transmitting station waits for a randomly set time before starting transmission to avoid frame collisions. When carrier sense determines that the wireless channel is idle, the base station device begins a countdown for the CW. When the CW reaches 0, it obtains the transmission right for the first time and transmits a transmit frame to the terminal device. Note that if carrier sense determines that the wireless channel is busy during the CW countdown, the base station stops the CW countdown. Then, if the wireless channel becomes idle, the base station device restarts the countdown for the remaining CWs following the previous IFS.

[0030] Next, the details of frame reception are explained. The terminal device as a receiving station receives the transmission frame, reads the PHY header of the transmission frame, and demodulates the received transmission frame. Then, the terminal device can identify whether the transmission frame is destined for the device itself by reading the MAC header of the demodulated signal. It should be noted that the terminal device can also determine the destination of the transmission frame based on the information recorded in the PHY header (for example, the group identifier (GID: Group identifier, Group ID) recorded in the VHT-SIG-A).

[0031] When a terminal device determines that the received transmission frame is destined for the device itself and is able to demodulate the transmission frame correctly, it must send an ACK frame indicating that the frame was correctly received to the base station device, which is the transmitting station. The ACK frame is one of the highest priority transmission frames sent during the SIFS period (not occupying the random backoff time). The base station device ends a series of communications upon receiving the ACK frame sent by the terminal device. It should be noted that if the terminal device cannot accurately receive the frame, the terminal device does not send an ACK. Therefore, if the base station device does not receive an ACK frame from the receiving station within a certain period of time (SIFS + ACK frame length) after the frame is sent, it considers the communication to have failed and ends the communication. In this way, the end of a communication (also called a burst) in the IEEE802.11 system must be determined by whether or not an ACK frame is received, except in special cases such as when sending broadcast signals such as beacon frames and when using fragmentation to divide the transmission data.

[0032] When the terminal device determines that the received transmission frame is not destined for the device itself, it sets the network allocation vector (NAV) based on the length (Length) of the transmission frame recorded in the PHY header, etc. The terminal device does not attempt communication during the period set to NAV. That is, the terminal device performs the same action as when the wireless channel is determined to be busy through the physical CS during the period set to NAV, so the communication control based on NAV is also called virtual carrier sensing (virtual CS). In addition to the case of setting based on the information recorded in the PHY header, NAV is also set by the transmission request (RTS: Request to send) frame and the reception preparation completion (CTS: Clear to send) frame introduced to eliminate the hidden terminal problem.

[0033] Each device performs carrier sensing and autonomously obtains transmission rights for the DCF. A control station called a point coordinator (PC) in the PCF controls the transmission rights of each device within the BSS. Typically, a base station is a PC and obtains transmission rights from terminal devices within the BSS.

[0034] The communication period based on PCF includes a non-contention period (CFP: Contention free period) and a contention period (CP: Contention period). During the CP period, communication is performed based on the above-mentioned DCF, and during the CFP period, the PC controls the transmission right. Before the communication of the PCF, the base station device serving as the PC broadcasts a beacon frame that records the CFP period (CFP Max duration: CFP maximum duration) and the like into the BSS. It should be noted that PIFS is used in the transmission of the beacon frame broadcast at the start of the transmission of the PCF, and it is transmitted without waiting for the CW. The terminal device that receives the beacon frame sets the CFP period recorded in the beacon frame as NAV. Afterwards, until the signal (for example, a data frame including CF-end) that the NAV passes through or the end of the CFP broadcast into the BSS is received, the terminal device can obtain the transmission right only when it receives a signal (for example, a data frame including CF-poll) sent by the PC to notify the acquisition of the transmission right through signaling. It should be noted that, during the CFP period, no frame collision occurs within the same BSS, and therefore, each terminal device does not occupy the random backoff time used in the DCF.

[0035] The wireless medium can be divided into multiple resource units (RUs). Figure 1 This is a schematic diagram showing an example of the division state of the wireless medium. For example, in resource division example 1, the wireless communication device can divide the frequency resources (subcarriers) as the wireless medium into nine RUs. Similarly, in resource division example 2, the wireless communication device can divide the subcarriers as the wireless medium into five RUs. Of course, Figure 1 The resource division example shown is only an example. For example, multiple RUs may also be composed of different numbers of subcarriers. In addition, the wireless medium divided into RUs can include not only frequency resources but also space resources. A wireless communication device (such as an access point device) can simultaneously send frames to multiple terminal devices (such as multiple station devices) by configuring frames with different terminal devices as destinations in each RU. The access point device can record the information indicating the division status of the wireless medium (Resource allocation information) as common control information in the PHY header of the frame sent by the device itself. Moreover, the access point device can record the information indicating the RU configured with frames with each station device as destination (resource unit assignment information) as inherent control information in the PHY header of the frame sent by the device itself.

[0036] Furthermore, multiple terminal devices (e.g., multiple station devices) can simultaneously transmit frames by assigning each frame to an assigned RU and then transmitting it. Multiple station devices can receive a frame (Triggerframe: TF) containing trigger information sent from an access point device and then wait for a specified period before transmitting frames. Each station device can determine the RU assigned to it based on the information contained in the TF. Furthermore, each station device can obtain a RU through random access based on the TF.

[0037] The access point device can simultaneously allocate multiple RUs to a single station device. The multiple RUs can consist of either contiguous or discontiguous subcarriers. The access point device can transmit a single frame using the multiple RUs allocated to a single station device, or can allocate and transmit multiple frames to different RUs. At least one of the multiple frames can include common control information for transmitting resource allocation information to multiple station devices.

[0038] A station device can be allocated multiple RUs from an access point device. The station device can use the allocated multiple RUs to transmit a single frame. Furthermore, the station device can use the allocated multiple RUs to allocate and transmit multiple frames to different RUs. The multiple frames can be of different frame types.

[0039] The access point device can also assign multiple AIDs to a single station device. The access point device can allocate RUs to each of the multiple AIDs assigned to a single station device. The access point device can use the RUs allocated to each of the multiple AIDs assigned to a single station device to transmit different frames. The different frames can be of different frame types.

[0040] A station device can also be assigned multiple AIDs from an access point device. A station device can allocate RUs to each of the multiple AIDs allocated to it. A station device can identify the RUs allocated to each of the multiple AIDs allocated to it as RUs allocated to all of its own devices and send a single frame using the multiple RUs allocated to it. In addition, a station device can send multiple frames using the multiple RUs allocated to it. In this case, information indicating the AIDs associated with the respective RUs allocated to it can be recorded in the multiple frames and sent. A station device can use the RUs allocated to each of the multiple AIDs allocated to it to send different frames. The different frames can be frames of different frame types.

[0041] Hereinafter, information exchanged between a wireless communication device and another wireless communication device during communication is also referred to as data.

[0042] The wireless communication device has either or both of a function of transmitting PPDU and a function of receiving PPDU. Figure 2 This diagram shows an example of the structure of a PPDU transmitted by a wireless communication device. A PPDU compliant with the IEEE 802.11a / b / g standards includes an L-STF, L-LTF, L-SIG, and a data frame (MAC frame, MAC frame, payload, data section, data, information bits, etc.). A PPDU compliant with the IEEE 802.11n standard includes an L-STF, L-LTF, L-SIG, HT-SIG, HT-STF, HT-LTF, and a data frame. A PPDU compliant with the IEEE 802.11ac standard includes an L-STF, L-LTF, L-SIG, VHT-SIG-A, VHT-STF, VHT-LTF, VHT-SIG-B, and part or all of the data frame. The PPDU in the IEEE 802.11ax standard consists of the L-STF, L-LTF, L-SIG, the L-SIG's temporally repeated RL-SIG, HE-SIG-A, HE-STF, HE-LTF, HE-SIG-B, and part or all of the data frame. The PPDU studied in the IEEE 802.11be standard consists of the L-STF, L-LTF, L-SIG, RL-SIG, U-SIG, EHT-SIG, EHT-STF, EHT-LTF, and part or all of the data frame.

[0043] Depend on Figure 2 The L-STF, L-LTF, and L-SIG enclosed by the dotted lines in the figure are common components of the IEEE 802.11 standard (hereinafter, L-STF, L-LTF, and L-SIG are collectively referred to as the L-header). For example, a wireless communication device compliant with the IEEE 802.11a / b / g standards can properly receive the L-header within a PPDU compliant with the IEEE 802.11n / ac / ax / be standards. A wireless communication device compliant with the IEEE 802.11a / b / g standards can receive a PPDU compliant with the IEEE 802.11n / ac / ax / be standards as if it were a PPDU compliant with the IEEE 802.11a / b / g standards.

[0044] However, wireless communication devices that comply with the IEEE802.11a / b / g standards cannot demodulate the PPDU that complies with the IEEE802.11n / ac / ax / be standards after the L-header, and therefore cannot demodulate information related to the transmitter address (TA), receiver address (RA), and duration / ID field used for NAV settings.

[0045] IEEE 802.11 specifies a method for inserting duration information into the L-SIG as a method for wireless communication devices compliant with the IEEE 802.11a / b / g standards to appropriately set the NAV (or perform reception operations for a specified period of time). Information related to the transmission rate (RATE field, L_RATE field, L_RATE, L_DATARATE, L_DATARATEfield) and information related to the transmission period (LENGTH field, L_LENGTH field, L_LENGTH) within the L-SIG are used by wireless communication devices compliant with the IEEE 802.11a / b / g standards to appropriately set the NAV.

[0046] Figure 3 FIG. 1 is a diagram showing an example of a method of inserting duration information into L-SIG. Figure 3 As an example, the PPDU structure corresponding to the IEEE802.11ac standard is shown, but the PPDU structure is not limited to this. It can also be a PPDU structure corresponding to the IEEE802.11n standard and a PPDU structure corresponding to the IEEE802.11ax standard. TXTIME has information about the length of the PPDU, aPreambleLength has information about the length of the preamble (L-STF+L-LTF), and aPLCPHeaderLength has information about the length of the PLCP header (L-SIG). L_LENGTH is based on the signal extension (Signal Extension) which is a virtual time period set to obtain compatibility with the IEEE802.11 standard, N associated with L_RATE ops, aSymbolLength, which is information about the period of one symbol (symbol, OFDM symbol, etc.), aPLCPServiceLength indicating the number of bits included in the PLCP service field, and aPLCPConvolutionalTailLength indicating the number of tail bits of the convolution symbol. The wireless communication device can calculate L_LENGTH and insert L-SIG. In addition, the wireless communication device can calculate the L-SIG duration. The L-SIG duration indicates information about the period that adds up the PPDU including the L_LENGTH, the Ack expected to be sent by the destination wireless communication device as a response, and the SIFS period.

[0047] Figure 9 An example of the format of a MAC frame is shown in FIG. Figure 2 Data frame (MAC Frame, MAC frame, payload, data part, data, information bits, etc.), Figure 3 The MAC frame in the MAC frame includes: Frame Control, Duration / ID, Address 1, Address 2, Address 3, Sequence Control, Address 4, QoS Control, HT Control, Frame Body, and FCS.

[0048] Figure 4 This is a diagram showing an example of the L-SIG duration in L-SIG TXOP Protection. DATA (frame, payload, data, etc.) consists of a portion or both of the MAC frame and the PLCP header. In addition, BA is a block Ack or Ack. The PPDU can include L-STF, L-LTF, and L-SIG, and can be configured to include any one or more of DATA, BA, RTS, or CTS. Figure 4 In the example shown, L-SIG TXOP protection is shown using RTS / CTS, but CTS-to-Self can also be used. Here, the MAC duration is the period indicated by the value of the Duration / ID field. In addition, the initiator can send a CF_End frame to notify the end of the L-SIG TXOP protection period.

[0049] Next, a method for identifying a BSS based on frames received by a wireless communication device is described. To enable a wireless communication device to identify a BSS based on received frames, the wireless communication device transmitting the PPDU preferably inserts information for identifying the BSS (BSS color, BSS identification information, or a BSS-specific value) into the PPDU. Information indicating the BSS color can be described as a HE-SIG-A.

[0050] A wireless communication device can transmit the L-SIG multiple times (L-SIG repetition). For example, the receiving wireless communication device can improve L-SIG demodulation accuracy by using MRC (Maximum Ratio Combining) to receive the multiple transmitted L-SIGs. Furthermore, if the wireless communication device accurately receives the L-SIG using MRC, it can interpret the PPDU containing the L-SIG as a PPDU compliant with the IEEE 802.11ax standard.

[0051] During the reception of a PPDU, a wireless communication device can also receive a portion of a PPDU other than the PPDU (e.g., the preamble, L-STF, L-LTF, PLCP header, etc. specified in IEEE 802.11) (also known as a dual reception operation). If a portion of a PPDU other than the PPDU is detected during the reception of a PPDU, the wireless communication device can update some or all of the information related to the destination address, source address, PPDU, or DATA period.

[0052] ACK and BA may also be referred to as responses (response frames). In addition, probe responses, authentication responses, and connection responses may also be referred to as responses. [1. First embodiment]

[0053] Figure 5This diagram shows an example of a wireless communication system according to this embodiment. A wireless communication system 3-1 includes a wireless communication device 1-1 and wireless communication devices 2-1 to 2-3. It should be noted that the wireless communication device 1-1 is also referred to as the base station device 1-1, and the wireless communication devices 2-1 to 2-3 are also referred to as the terminal devices 2-1 to 2-3. Furthermore, the wireless communication devices 2-1 to 2-3 and the terminal devices 2-1 to 2-3, as devices connected to the wireless communication device 1-1, are also referred to as the wireless communication device 2A and the terminal device 2A. The wireless communication devices 1-1 and 2A are wirelessly connected and are in a state where they can transmit and receive PPDUs to each other. Furthermore, in addition to the wireless communication system 3-1, the wireless communication system according to this embodiment may also include a wireless communication system 3-2. The wireless communication system 3-2 includes the wireless communication device 1-2 and wireless communication devices 2-4 to 2-6. It should be noted that the wireless communication device 1-2 is also referred to as the base station device 1-2, and the wireless communication devices 2-4 to 2-6 are also referred to as the terminal devices 2-4 to 2-6. Furthermore, wireless communication devices 2-4 to 2-6 and terminal devices 2-4 to 2-6 are also referred to as wireless communication devices 2B and terminal devices 2B as devices connected to wireless communication device 1-2. The wireless communication system 3-1 and the wireless communication system 3-2 form different BSSs, but this does not necessarily mean that the ESSs (Extended Service Sets) are different. An ESS represents a set of services that form a LAN (Local Area Network). That is, wireless communication devices belonging to the same ESS can be considered by upper layers to belong to the same network. Furthermore, BSSs are combined via a DS (Distribution System) to form an ESS. It should be noted that the wireless communication systems 3-1 and 3-2 may each include multiple wireless communication devices.

[0054] exist Figure 5 In the following description, it is assumed that the signal transmitted by wireless communication device 2A reaches wireless communication device 1-1 and wireless communication device 2B, but does not reach wireless communication device 1-2. That is, when wireless communication device 2A transmits a signal using a certain channel, wireless communication device 1-1 and wireless communication device 2B determine that channel to be busy, while wireless communication device 1-2 determines that channel to be idle. Furthermore, it is assumed that the signal transmitted by wireless communication device 2B reaches wireless transmission device 1-2 and wireless communication device 2A, but does not reach wireless communication device 1-1. That is, when wireless communication device 2B transmits a signal using a certain channel, wireless communication device 1-2 and wireless communication device 2A determine that channel to be busy, while wireless communication device 1-1 determines that channel to be idle.

[0055] Figure 6This figure shows an example of the device configuration of wireless communication devices 1-1, 1-2, 2A, and 2B (hereinafter collectively referred to as wireless communication device 10-1, station device 10-1, or simply station device). Wireless communication device 10-1 includes an upper layer unit (upper layer processing step) 10001-1, an autonomous distributed control unit (autonomous distributed control step) 10002-1, a transmitting unit (transmitting step) 10003-1, a receiving unit (receiving step) 10004-1, and an antenna unit 10005-1.

[0056] The upper layer unit 10001-1 processes information processed within this wireless communication device (information related to transmitted frames, MIB (Management Information Base) etc.) and frames received from other wireless communication devices at layers higher than the physical layer, such as the MAC layer and LLC layer.

[0057] Upper layer unit 10001-1 can notify autonomous distributed control unit 10002-1 of information related to frames and services sent to the wireless medium. This information can include, for example, control information included in management frames such as beacons, or measurement information reported by other wireless communication devices with the wireless communication device as the destination. Furthermore, the destination can be unrestricted (it can be the wireless communication device itself or another device, and can be broadcast or multicast), and can include control information included in management frames and control frames.

[0058] Figure 7 This figure shows an example of the device configuration of the autonomous distributed control unit 10002-1. The autonomous distributed control unit 10002-1, also referred to as the control unit 10002-1, includes a CCA unit (CCA step) 10002a-1, a backoff unit (backoff step) 10002b-1, and a transmission determination unit (transmission determination step) 10002c-1.

[0059] The CCA unit 10002a-1 can use either or both of the information regarding the power of the received signal received via the radio resource and the information regarding the received signal (including decoded information) notified from the receiving unit 10004-1 to determine the status of the radio resource (including whether the radio resource is busy or idle). The CCA unit 10002a-1 can notify the backoff unit 10002b-1 and the transmission determination unit 10002c-1 of the radio resource status determination information.

[0060] Backoff unit 10002b-1 can use radio resource status information to perform backoff. Backoff unit 10002b-1 generates a CW and has a countdown function. For example, if the radio resource status information indicates an idle state, the CW countdown can be started; if the radio resource status information indicates a busy state, the CW countdown can be stopped. Backoff unit 10002b-1 can also notify transmission decision unit 10002c-1 of the CW value.

[0061] Transmission determination unit 10002c-1 uses either or both the radio resource status determination information and the CW value to make a transmission determination. For example, if the radio resource status determination information indicates idle and the CW value is 0, the transmission determination information can be notified to transmission unit 10003-1. Furthermore, if the radio resource status determination information indicates idle, the transmission determination information can be notified to transmission unit 10003-1.

[0062] The transmitting unit 10003-1 is composed of a physical layer frame generation unit (physical layer frame generation step) 10003a-1 and a wireless transmitting unit (wireless transmitting step) 10003b-1. It should be noted that the physical layer frame generation unit (physical layer frame generation step) can also be referred to as a frame generation unit (frame generation step). The physical layer frame generation unit 10003a-1 has the function of generating a physical layer frame (hereinafter also referred to as a frame, PPDU) based on the transmission judgment information notified from the transmission judgment unit 10002c-1. The physical layer frame generation unit 10003a-1 includes an encoding unit that performs error correction coding on the data received from the upper layer and generates a coding block. In addition, the physical layer frame generation unit 10003a-1 also has the function of performing modulation, precoding filter multiplication, etc. The physical layer frame generation unit 10003a-1 transmits the generated physical layer frame to the wireless transmitting unit 10003b-1.

[0063] The frame generated by the physical layer frame generator 10003a-1 includes a trigger frame instructing the wireless communication device as the destination terminal to transmit the frame. The trigger frame includes information indicating the RU used by the wireless communication device instructed to transmit the frame.

[0064] The wireless transmitter 10003b-1 converts the physical layer frame generated by the physical layer frame generator 10003a-1 into a radio frequency (RF) signal, generating a radio frequency signal. The processing performed by the wireless transmitter 10003b-1 includes digital-to-analog conversion, filtering, and frequency conversion from baseband to RF.

[0065] Receiving unit 10004-1 includes a wireless receiving unit (wireless receiving step) 10004a-1 and a signal demodulating unit (signal demodulating step) 10004b-1. Receiving unit 10004-1 generates information related to received signal power based on the RF band signal received by antenna unit 10005-1. Receiving unit 10004-1 can notify CCA unit 10002a-1 of information related to received signal power and received signal information.

[0066] The wireless receiving unit 10004a-1 converts the RF band signal received by the antenna unit 10005-1 into a baseband signal and generates a physical layer signal (e.g., a physical layer frame). The processing performed by the wireless receiving unit 10004a-1 includes frequency conversion from the RF band to the baseband, filtering, and analog / digital conversion.

[0067] The signal demodulation unit 10004b-1 has the function of demodulating the physical layer signal generated by the wireless reception unit 10004a-1. The processing performed by the signal demodulation unit 10004b-1 includes channel equalization, demapping, and error correction decoding. The signal demodulation unit 10004b-1 can extract, from the physical layer signal, information such as the information included in the PHY header, the information included in the MAC header, and the information included in the transmission frame. The signal demodulation unit 10004b-1 can notify the upper layer unit 10001-1 of the extracted information. It should be noted that the signal demodulation unit 10004b-1 can extract any or all of the information included in the PHY header, the information included in the MAC header, and the information included in the transmission frame. The evaluation unit (evaluation step) (10004c-1) performs a predetermined evaluation on the information included in the PHY header, MAC header, etc. thus extracted, and notifies the upper layer unit of the results of the evaluation.

[0068] The antenna unit 10005-1 has the function of transmitting the radio frequency signal generated by the radio transmission unit 10003b-1 to the wireless space. In addition, the antenna unit 10005-1 has the function of receiving the radio frequency signal and passing it to the radio reception unit 10004a-1.

[0069] The wireless communication device 10-1 can cause wireless communication devices around the wireless communication device to set NAV only during this period by recording information indicating the period during which the wireless communication device uses the wireless medium in the PHY header or MAC header of the frame to be transmitted. For example, the wireless communication device 10-1 can record the information indicating the period in the duration / ID field or the LENGTH field of the frame to be transmitted. The NAV period set for the wireless communication devices around the wireless communication device is called the TXOP period obtained by the wireless communication device 10-1 (or simply called TXOP). In addition, the wireless communication device 10-1 that obtains the TXOP is called the TXOP holder. The frame type of the frame sent by the wireless communication device 10-1 to obtain the TXOP is not limited to any frame type and can be a control frame (such as an RTS frame or a CTS-to-self frame) or a data frame.

[0070] Wireless communication device 10-1, as the TXOP holder, can transmit frames to wireless communication devices other than itself during the TXOP. If wireless communication device 1-1 is the TXOP holder, it can transmit frames to wireless communication device 2A during the TXOP period. Furthermore, wireless communication device 1-1 can instruct wireless communication device 2A to transmit frames destined for wireless communication device 1-1 during the TXOP period. Wireless communication device 1-1 can also transmit a trigger frame containing information instructing transmission of frames destined for wireless communication device 1-1 to wireless communication device 2A during the TXOP period.

[0071] The wireless communication device 1 - 1 may secure TXOPs for all communication bands where frames may be transmitted (eg, operation bandwidth), or may secure a specific communication band such as a communication band where frames are actually transmitted (eg, transmission bandwidth).

[0072] The wireless communication device that instructs wireless communication device 1-1 to transmit frames within the TXOP period obtained is not necessarily limited to the wireless communication device connected to the wireless communication device. For example, the wireless communication device can instruct wireless communication devices not connected to the wireless communication device to transmit frames, thereby causing wireless communication devices located near the wireless communication device to transmit management frames such as reassociation frames and control frames such as RTS / CTS frames.

[0073] Furthermore, the TXOP in EDCA, a data transmission method different from DCF, is explained. The IEEE 802.11e standard covers EDCA and defines TXOPs from the perspective of QoS (Quality of Service) guarantees for various services, such as video transmission and VoIP (Voice over IP). Services are broadly categorized into four access categories: VO (Voice), VI (Video), BE (Best Effort), and BK (Background). Generally speaking, the order of priority is VO, VI, BE, and BK. Each access category has parameters such as the minimum CWmin and maximum CWmax values ​​for the CW, AIFS (Arbitration IFS), a type of IFS, and the TXOP limit, which is the upper limit of transmission opportunities. The values ​​are set to indicate the priority level. For example, by setting the CWmin, CWmax, and AIFS for the highest-priority VO (Voice over Voice), which is dedicated to voice transmission, to relatively lower values ​​compared to other access categories, data transmission can be prioritized over other access categories. For example, by setting a larger TXOP limit for the VI (Voice over Video), which transmits a large amount of data, transmission opportunities can be extended compared to other access categories. In this way, the values ​​of the four parameters for each access category are adjusted to ensure QoS for various services.

[0074] Next, use Figure 8 An example of direct link installation is described below. Figure 8 In the reference numerals used in Figure 5 The same reference numerals as in Figure 5 The figures described in the figure are the same. The wireless system 3-1 includes: a base station device 1-1, a terminal device 2-1 (wireless communication device 2-1), a terminal device 2-2 (wireless communication device 2-2), and a terminal device 2-3 (wireless communication device 2-3). When the terminal device 2-2 sends data to the terminal device 2-1, the communication (4-1) via the base station device 1-1 and the direct communication (4-2) from the terminal device 2-2 to the terminal device 2-1 without passing through the base station device 1-1 are set as direct links. When a direct link is used, the terminal device 2-1 sends a direct link discovery request to the terminal device 2-2 via the base station device 1-1. The terminal device 2-2 that receives the direct link discovery request via the base station device 1-1 sends a direct link discovery response to the terminal device 2-1 using a direct path. By successfully receiving the direct link discovery response by the terminal device 2-1, it can be known that direct communication can be performed between the terminal device 2-1 and the terminal device 2-2.

[0075] Terminal device 2-1 then transmits a direct link establishment request to terminal device 2-2 via base station device 1-1. Terminal device 2-1 that transmits the direct link establishment request is sometimes referred to as the initiator. Terminal device 2-2, having received the direct link establishment request, transmits a direct link establishment response to terminal device 2-1 via base station device 1-1. Terminal device 2-2 that transmits the direct link establishment response is sometimes referred to as the responder. Assuming that the direct link is established after the direct link establishment request and direct link establishment response are exchanged normally, terminal devices 2-1 and 2-2 can communicate directly with each other without intermediary base station device 1-1. Various control information may be included in the direct link establishment request and direct link establishment response. For example, this may include information used for encrypted communication, such as information related to encryption keys. If information used for encrypted communication is also exchanged during the exchange of the direct link establishment request and direct link establishment response, encryption may also be used in the direct link.

[0076] When setting direct communication, when PD-based SR is designated as the intra-BSS SR method, the base station apparatus 1 - 1 may include information on the maximum allowed transmission power in the SR link information.

[0077] Figure 9 It is a diagram showing an example of the relationship between the threshold of the reception power detection level for channel access and the maximum allowed transmission power. This example may be an example of a case where the base station device 1-1 does not include the information of the maximum allowed transmission power in the SR link information. In the case where the base station device 1-1 does not include the information of the maximum allowed transmission power in the SR link information, the threshold of the reception power detection level is required to be less than or equal to P1. The terminal device that receives the SR link information can transmit when the reception power detection level is less than or equal to the threshold. The power in the transmission is required to be less than or equal to the maximum allowed transmission power TX PWRmax. Here, the value of TX_PWRmax may also be constant regardless of the size of the threshold used. It should be noted that when the reception power detection level exceeds the threshold, transmission cannot be performed.

[0078] Figure 10It is a diagram showing an example of the relationship between the threshold value of the reception power detection level for channel access and the maximum allowed transmission power. This example may be an example of a case where the base station device 1-1 includes information on the maximum allowed transmission power in the SR link information. In the case where the base station device 1-1 includes information on the maximum allowed transmission power in the SR link information, the information in the SR link information may represent the maximum allowed transmission power TX_PWRref applied when the threshold value is sufficiently low. It should be noted that, preferably, TX_PWRref is a value lower than TX_PWRmax. Thus, compared to when TX_PWRmax is used, interference can be suppressed, so that multiple nodes can share the same channel.

[0079] The threshold of the reception power detection level is required to be less than or equal to P2. The terminal device that receives the SR link information can transmit when the reception power detection level is less than or equal to the threshold. The power in the transmission is required to be less than or equal to the maximum transmission power allowed. Here, when the threshold is between P1 and P2, the maximum transmission power allowed becomes higher in proportion to the lower threshold. When the threshold is less than or equal to P1, the maximum transmission power allowed can be constant at TX_PWRref regardless of the size of the threshold used. In this example, Figure 9 Compared with the example shown, even if the threshold value is larger than P1, as long as it is smaller than P2, transmission is possible when the reception power detection level is lower than the threshold.

[0080] Figure 11 It is a diagram showing an example of the relationship between the threshold value of the reception power detection level for channel access and the maximum allowed transmission power. This example may be an example of a case where the base station device 1-1 includes information on the maximum allowed transmission power in the SR link information. In the case where the base station device 1-1 includes information on the maximum allowed transmission power in the SR link information, the information in the SR link information may represent the maximum allowed transmission power TX_PWRref applied when the threshold value is sufficiently low. It should be noted that, preferably, TX_PWRref is a value lower than TX_PWRmax. Thus, compared to when TX_PWRmax is used, interference can be suppressed, so that multiple nodes can share the same channel.

[0081] The threshold of the reception power detection level is required to be less than or equal to P2. The terminal device that receives the SR link information can transmit when the reception power detection level is less than or equal to the threshold. The power in the transmission is required to be less than or equal to the maximum transmission power allowed. Here, when the threshold is between P1 and P2, the maximum transmission power allowed is gradually increased as the threshold becomes lower. When the threshold is less than or equal to P1, the maximum transmission power allowed can be constant at TX_PWRref regardless of the size of the threshold used. In this example, Figure 9 Compared with the example shown, even if the threshold value is larger than P1, as long as it is smaller than P2, transmission is possible when the reception power detection level is lower than the threshold.

[0082] In this manner, the base station device transmitting SR link information determines whether to include information on the maximum allowable transmit power in the SR link information. If it is determined that the information is included, the base station device transmits the SR link information including the information on the maximum allowable transmit power. If it is determined that the information is not included, the base station device transmits the SR link information without the information on the maximum allowable transmit power.

[0083] The terminal device that receives the SR link information determines whether the SR link information includes information on the maximum allowable transmission power. If it is determined that it is not included, the terminal device uses the specified value as the maximum allowable transmission power when transmitting. If it is determined that it is included, the terminal device uses the information on the maximum allowable transmission power to determine the maximum allowable transmission power when transmitting. The terminal device sets a threshold. The terminal device transmits when the received power detection level is less than or equal to (or less than) the threshold. At this time, a value less than or equal to the maximum allowable transmission power is set as the transmission power.

[0084] When the terminal device sets the threshold, if it is determined that the SR link information includes information on the maximum allowable transmission power, the terminal device sets a value equal to or less than P2 as the threshold. When the terminal device sets the threshold, if it is determined that the SR link information does not include information on the maximum allowable transmission power, the terminal device sets a value equal to or less than P1 as the threshold.

[0085] In the case where it is determined that the SR link information includes information on the maximum allowable transmit power and the threshold is set to be less than or equal to P1, the value represented by the information on the maximum allowable transmit power is determined as the maximum allowable transmit power. In the case where it is determined that the SR link information includes information on the maximum allowable transmit power and the threshold is set between P1 and P2, the value obtained by subtracting the value corresponding to the difference between the threshold and P1 from the value represented by the information on the maximum allowable transmit power is determined as the maximum allowable transmit power. The value obtained by subtracting the value corresponding to the difference between the threshold and P1 may be a value that increases in proportion to the difference between the threshold and P1. Alternatively, the value obtained by subtracting the value corresponding to the difference between the threshold and P1 may be a value that increases in stages as the difference between the threshold and P1 increases.

[0086] A communication device according to one embodiment of the present invention can communicate in frequency bands (spectrums) known as unlicensed bands, which do not require national or regional licenses for use. However, the usable frequency bands are not limited to these. For example, the communication device according to one embodiment of the present invention can also achieve this effect in frequency bands known as white bands (for example, frequency bands allocated for television broadcasting but not used depending on the region) that are not actually used for purposes such as preventing inter-frequency interference, despite being licensed for use by a national or regional government for specific services, and in shared spectrum (shared frequency bands) expected to be shared by multiple operators.

[0087] The program operating in the wireless communication device of one embodiment of the present invention is a program that controls a CPU (Central Processing Unit) or the like to implement the functions of the aforementioned embodiment of one embodiment of the present invention (a program that causes the computer to function). Furthermore, information processed by these devices is temporarily stored in RAM (Random Access Memory) during processing, and then stored in various ROMs (Read-Only Memory) and HDDs (Hard Disk Drives), where it is read, modified, or written to by the CPU as needed. The recording medium storing the program may be any of semiconductor media (e.g., ROMs, nonvolatile memory cards, etc.), optical recording media (e.g., DVDs (Digital Video Discs), MOs (Magneto-Optical Disks), MDs (Mini Discs), CDs (Compact Discs), BDs (Blu-ray Discs), etc.), or magnetic recording media (e.g., magnetic tapes, floppy disks, etc.). Furthermore, by executing the loaded program, not only the functions of the above-described embodiments are realized, but the functions of the present invention may also be realized by performing processing in conjunction with an operating system or other application programs based on instructions from the program.

[0088] In addition, when circulating in the market, the program can be stored in a removable recording medium to circulate it, or transmitted 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 one embodiment of the present invention. In addition, part or all of the communication device of the above embodiment can also be implemented as a typical integrated circuit, namely LSI (Large Scale Integration). The functional blocks of the communication device can be individually chipped, or part or all of them can be integrated and chipped. When the functional blocks are integrated into an integrated circuit, an integrated circuit control unit is added to control them.

[0089] Furthermore, the method of integrated circuit formation is not limited to LSI, and can also be achieved by a dedicated circuit or a general-purpose processor. In addition, if an integrated circuit formation technology that replaces LSI emerges with the advancement of semiconductor technology, an integrated circuit based on this technology can also be used.

[0090] It should be noted that the present invention is not limited to the aforementioned embodiments. The wireless communication device of the present invention is not limited to application to mobile stations and can also be applied to fixed or non-mobile electronic devices installed indoors or outdoors, such as AV (Audio Video) equipment, kitchen appliances, cleaning / washing equipment, air conditioners, office equipment, vending machines, and other household appliances.

[0091] While the embodiments of the present invention have been described in detail with reference to the drawings, the specific configuration is not limited to the embodiments, and designs and the like that do not depart from the gist of the present invention are also included in the scope of the claims. Industrial applicability

[0092] One aspect of the present invention is applicable to a communication device and a communication method. Description of Reference Numerals 1-1, 1-2, 2-1 to 2-6, 2A, 2B: Wireless communication devices 3-1, 3-2: Management scope 7-1, 7-2, 7-3, 7-4: Section 10-1: Wireless Communication Device 10001-1: Upper Level 10002-1: (Autonomous Decentralized) Control Unit 10002a-1: CCA Department 10002b-1: Retreat 10002c-1: Sending judgment unit 10003-1: Transmission Department 10003a-1: Physical layer frame generation unit 10003b-1: Wireless transmission unit 10004-1: Receiving Department 10004a-1: Wireless receiving unit 10004b-1: Signal demodulation unit 10004c-1: Evaluation Department 10005-1: Antenna 100-1, 100-3, 100-6, 100-11: Busy 100-4, 100-7: Random backoff 100-2, 100-5, 100-8, 100-10: Wireless frames 1401, 1421: Wireless frames

Claims

1. A terminal device, wherein: It includes a sending part and a receiving part. The receiving unit receives scheduling request SR link information including information on the maximum allowed transmission power, When the reception power received by the receiving unit is less than or equal to a threshold, the transmitting unit transmits a transmission frame. When sending the transmission frame, the transmission power is set to be less than or equal to the maximum allowed transmission power, When the threshold is less than or equal to a first value, the allowed maximum transmission power is set to a value indicated by the information of the allowed maximum transmission power, When the threshold is greater than a first value and less than or equal to a second value, the allowed maximum transmission power is set to a value obtained based on a value indicated by the information on the allowed maximum transmission power and the threshold.

2. A base station device, wherein: Including the sending department, The transmitting unit transmits scheduling request (SR) link information including information on the maximum allowed transmission power.

3. A communication method, which is a communication method in a terminal device, wherein: Receiving scheduling request SR link information including information on the maximum allowed transmit power; When the received power is less than or equal to the threshold, a transmit frame is sent; When sending the transmission frame, the transmission power is set to be less than or equal to the maximum allowed transmission power; When the threshold is less than or equal to a first value, the allowed maximum transmission power is set to a value indicated by the information of the allowed maximum transmission power; as well as When the threshold is greater than a first value and less than or equal to a second value, the allowed maximum transmission power is set to a value obtained based on a value indicated by the information on the allowed maximum transmission power and the threshold.

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