Access point device, station device, and wireless communication system

Abstract

To provide a multi-link access point device that notifies, with a small amount of information, information on the presence or absence of a frame being buffered and on a link designated or recommended to be used, to a multi-link station device operating in a power management mode.SOLUTION: An access point device communicating with a plurality of station devices transmits, to the plurality of station devices, a management frame including association identification number AID bit map information and multi-link traffic display information. The multi-link traffic display information includes first information and second information. The first information includes a plurality of pieces of link offset information linked to traffic display bit maps. The AID bit map information includes information indicating that each of the traffic display bit maps is linked to one or more station devices, of the plurality of station devices connected with the access point device.SELECTED DRAWING: Figure 9

Description

[Technical field]

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

[0002] The Institute of Electrical and Electronics Engineers Inc. (IEEE) is continuously working on updating the specifications of IEEE802.11, the standard for wireless LAN (Local Area Network), to realize faster wireless LAN (Local Area Network) communication and more efficient frequency utilization. Wireless LAN can perform wireless communication using unlicensed bands that can be used without permission (license) from a country or region. For personal use such as at home, Internet access from within the home has been made wireless by including a wireless LAN access point function in a line termination device for connecting to a WAN (Wide Area Network) line to the Internet, or by connecting a wireless LAN access point device to a line termination device. In other words, a wireless LAN station device such as a smartphone or PC can connect to a wireless LAN access point device and access the Internet.

[0003] The IEEE802.11ax specification is expected to be finalized in 2020, and wireless LAN devices that comply with the draft specification and communication devices such as smartphones and PCs (Personal Computers) equipped with the wireless LAN devices have already appeared on the market as Wi-Fi6 (registered trademark, the name for IEEE-802.11ax-compliant products certified by the Wi-Fi Alliance) compatible products. Currently, standardization activities for IEEE802.11be, the successor to IEEE802.11ax, have begun. With the rapid spread of wireless LAN devices, the IEEE802.11be standardization is considering further improving the throughput per user in environments where wireless LAN devices are densely deployed.

[0004] Meanwhile, ETSI (European Telecommunications Standards Institute) in Europe and FCC (Federal Communications Commission) in the United States are considering allowing the use of the 6 GHz band (5.935 to 7.125 GHz) as an unlicensed band, and similar considerations are underway in other countries around the world. This means that wireless LANs are expected to be able to use the 6 GHz band in addition to the 2.4 GHz and 5 GHz bands. In order to accommodate the expansion of applicable frequencies, the Wi-Fi Alliance has formulated Wi-Fi6E (registered trademark), an extension of Wi-Fi6, which will use the 6 GHz band.

[0005] To be precise, the 6 GHz band is a frequency band between 5.935 and 7.125 GHz, and a total of about 1.2 GHz of bandwidth will be newly available, which means an increase of 14 channels in terms of 80 MHz-wide channels and 7 channels in terms of 160 MHz-wide channels. Since abundant frequency resources will be available, it is being considered to double the maximum channel bandwidth available to one wireless LAN communication system (equivalent to BSS, which will be described later) from 160 MHz in IEEE802.11ax to 320 MHz in IEEE802.11be (see Non-Patent Document 1).

[0006] The 2.4 GHz band has a relatively wide coverage (range of communication), but the available bandwidth is relatively narrow, and the effect of interference between communication devices is large. On the other hand, the 5 GHz and 6 GHz bands have a wide communication bandwidth, but the coverage is not wide. Therefore, in order to realize various services and applications with wireless LAN, it is desirable to bundle or switch the frequency bands (2.4 GHz, 5 GHz, 6 GHz, etc., or channels included in each frequency band, or subchannels included in the channel) used according to the use case. However, in conventional wireless LAN communication devices, it was not possible to bundle and use different frequency bands (2.4 GHz, 5 GHz, 6 GHz, etc.) used for communication. In addition, in order to switch frequency bands (2.4 GHz, 5 GHz, 6 GHz, etc.), it was necessary to once disconnect the current frequency band and connect to another frequency band.

[0007] Therefore, in the IEEE802.11be standardization, there is a discussion on multi-link operation (MLO) that enables a communication device to maintain multiple link connections using multiple frequency bands (see Non-Patent Document 2). As an example of MLO, three link connections, namely, a 2.4 GHz band connection, a 5 GHz band connection, and a 6 GHz band connection, are operated simultaneously. Of course, the combinations of frequency bands, channels, and subchannels are not limited to these combinations, and there are various combinations. From the viewpoint of frequency bands, in the future, millimeter waves (45 GHz band, 60 GHz band, etc.) can also be used as one link constituting Multi-Link. According to MLO, a communication device can maintain multiple link connections with different settings related to wireless resources and communication used. In other words, by using MLO, a communication device can simultaneously maintain link connections of different frequency bands. Not only can frames be transmitted and received using multiple links simultaneously, but it is also possible to switch link connections for transmitting and receiving frames (change frequency bands) without performing a reconnection operation. The links constituting the multiple links (Multi-Link) here are also called physical layer links. [Prior art documents] [Non-patent literature]

[0008] [Non-Patent Document 1] IEEE 802.11-20 / 0693-01-00be, May.2020 [Non-Patent Document 2] IEEE 802.11-19 / 0773-08-00be, Nov.2019 [Non-Patent Document 3] IEEE 802.11-20 / 0810-01-00be, Jul.2020 [Non-Patent Document 4] IEEE 802.11-22 / 1381-01-00be, Aug. 2022 Summary of the Invention [Problem to be solved by the invention]

[0009] When an MLD (Multi-Link Device) station device operating in MLO (Multi-Link Operation) operates in Power Management mode (Power Save mode, sleep mode), it intermittently receives management frames such as beacons to save power. It checks the contents of the received management frames and detects and determines whether the connected MLD access point device is buffering frames addressed to its own MLD station device. If it detects that the connected MLD access point device is buffering frames addressed to its own MLD station device, it transitions to an active mode in which frames can be sent and received, and receives the buffered frames.

[0010] It is desirable for an MLD access point device to notify each MLD station device of which link (physical layer link) to use or which is recommended for transmitting buffered (stored, pending transmission) frames. One method is disclosed in Reference 4, but there is an issue with the poor efficiency of the notification, such as the large number of information bits used for the notification. [Means for solving the problem]

[0011] In order to solve the above-mentioned problems, an access point device, a station device, and a wireless communication system according to the present invention are as follows.

[0012] (1) That is, an access point device according to one embodiment of the present invention is an access point device that communicates with a plurality of station devices, communicates with the plurality of station devices using a plurality of physical layer links, and includes a transmitter and a receiver corresponding to each of the plurality of physical layer links, and transmits a management frame including AID bitmap information and multilink traffic indication information to the plurality of station devices using any one of the transmitters, the multilink traffic indication information including first information and second information, the first information including a plurality of link offset information, each of the plurality of link offset information being traffic associated with each of the plurality of link offset information. the second information includes a traffic indication bitmap and an offset value corresponding thereto, the offset value indicating the physical layer link corresponding to the traffic indication bitmap; the second information includes link number information, the link number information indicating one or more of the physical layer links corresponding to the traffic indication bitmaps associated with each of the link offset information; the AID bitmap information includes information indicating that each of the traffic indication bitmaps is associated with one or more station devices connected to the access point device; there are a plurality of third information combining the first information and the second information, and each of the third information corresponds to a different maximum number of physical layer links.

[0013] (2) Moreover, in the access point device according to an aspect of the present invention as set forth in (1) above, a plurality of pieces of the third information are included in one piece of the multilink traffic display information.

[0014] (3) Furthermore, an access point device according to one embodiment of the present invention is described in (1) above, and includes a plurality of the multilink traffic display information in the management frame, and one of the multilink traffic display information includes one of the third information.

[0015] (4) An access point device according to one embodiment of the present invention is an access point device that communicates with a plurality of station devices, communicates with the plurality of station devices using a plurality of physical layer links, and has a transmitter and a receiver corresponding to each of the plurality of physical layer links, and transmits a management frame including AID bitmap information and multi-link traffic indication information to the plurality of station devices using one of the transmitters, the multi-link traffic indication information including link block information and a traffic indication bitmap, the link block information including a value indicating a combination of the traffic indication bitmap and the corresponding physical layer link associated with each of the link block information, and the AID bitmap information including information indicating that each of the traffic indication bitmaps is associated with one or more station devices among the plurality of station devices connected to the access point device.

[0016] (5) An access point device according to one embodiment of the present invention is an access point device that communicates with a plurality of station devices, communicates with the plurality of station devices using a plurality of physical layer links, and has a transmitter and a receiver corresponding to each of the plurality of physical layer links, and transmits a management frame including multi-link traffic indication information to the plurality of station devices using one of the transmitters, the multi-link traffic indication information including a link bitmap pattern and an AID bitmap, and the AID bitmap indicates the station device that uses the link bitmap pattern.

[0017] (6) An access point device according to one embodiment of the present invention is an access point device that communicates with a plurality of station devices, communicates with the plurality of station devices using a plurality of physical layer links, and has a transmitter and a receiver corresponding to each of the plurality of physical layer links, and transmits a management frame including multi-link traffic indication information to the plurality of station devices using one of the transmitters, and the multi-link traffic indication information includes a link number and an AID bitmap, and the AID bitmap indicates the station device that uses the link number.

[0018] (7) A station device according to one embodiment of the present invention is a station device that communicates with an access point device, and communicates using a plurality of physical layer links, and includes a transmitter and a receiver corresponding to each of the plurality of physical layer links, and receives a management frame including AID bitmap information and multilink traffic indication information for the plurality of station devices at any one of the receivers, the multilink traffic indication information including first information and second information, the first information including a plurality of link offset information, each of the plurality of link offset information including a traffic indication bitmap and a corresponding offset value associated with each of the plurality of link offset information. the offset value indicates the physical layer link corresponding to the traffic indication bitmap, the second information includes link number information, the link number information indicates one or more of the physical layer links corresponding to the traffic indication bitmaps associated with each of the link offset information, the AID bitmap information includes information indicating that each of the traffic indication bitmaps is associated with one or more station devices among the multiple station devices connected to the access point device, and there are multiple third information combining the first information and the second information, and each of the third information corresponds to a different number of maximum physical layer links.

[0019] (8) A wireless communication system according to one embodiment of the present invention is a wireless communication system including an access point device and a plurality of station devices communicating using a plurality of physical layer links, wherein the access point device transmits a management frame including AID bitmap information and multilink traffic indication information to the station devices, the multilink traffic indication information including first information and second information, the first information including a plurality of link offset information, each of the plurality of link offset information including an offset value corresponding to a traffic indication bitmap associated with each of the plurality of link offset information, the offset value indicating the physical layer link corresponding to the traffic indication bitmap, the second information including link number information, the link number information indicating one or more of the physical layer links corresponding to the traffic indication bitmap associated with each of the link offset information, the AID bitmap information including information indicating that each of the traffic indication bitmaps is associated with one or more station devices among the plurality of station devices connected to the access point device, and there are a plurality of third information combining the first information and the second information, and each of the third information has a different number of maximum physical layer links corresponding to it. Effect of the Invention

[0020] According to the present invention, an MLD access point device can efficiently notify an MLD station device operating in power management mode of the presence or absence of buffered (stored, pending transmission) frames. [Brief description of the drawings]

[0021] [Figure 1] FIG. 2 is a diagram illustrating an example of a frame configuration according to an embodiment of the present invention. [Diagram 2] FIG. 2 is a diagram illustrating an example of a frame configuration according to an embodiment of the present invention. [Diagram 3] FIG. 2 is a diagram illustrating an example of communication according to an embodiment of the present invention. [Figure 4] FIG. 2 is a schematic diagram illustrating an example of division of radio resources according to an aspect of the present invention. [Diagram 5] FIG. 1 is a diagram illustrating an example of a configuration of a communication system according to an aspect of the present invention. [Figure 6] 1 is a block diagram showing an example of a configuration of a wireless communication device according to an aspect of the present invention. [Figure 7] 1 is a block diagram showing an example of a configuration of a wireless communication device according to an aspect of the present invention. [Figure 8] FIG. 2 is a diagram illustrating an example of a frame configuration according to an embodiment of the present invention. [Figure 9] 1 is a block diagram showing an example of a configuration of a wireless communication device according to an aspect of the present invention. [Figure 10] FIG. 2 is a diagram illustrating frame transmission and reception according to an embodiment of the present invention. [Figure 11] FIG. 2 is a diagram illustrating frame transmission and reception according to an embodiment of the present invention. [Figure 12] FIG. 2 is a diagram illustrating an example of a frame configuration according to an embodiment of the present invention. [Figure 13] FIG. 2 is a diagram illustrating an example of a frame configuration according to an embodiment of the present invention. [Figure 14] FIG. 2 is a diagram illustrating an example of a frame configuration according to an embodiment of the present invention. [Figure 15] FIG. 2 is a diagram illustrating an example of a frame configuration according to an embodiment of the present invention. [Figure 16] FIG. 2 is a diagram illustrating an example of a frame configuration according to an embodiment of the present invention. [Figure 17] FIG. 2 is a diagram illustrating an example of a frame configuration according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0022] The communication system in this embodiment includes an access point device (also referred to as a base station device) and multiple station devices (also referred to as terminal devices). A communication system or network configured with the access point device and the station devices is called a basic service set (BSS: Basic service set, management range). A station device according to this embodiment can have the functions of an access point device. Similarly, an access point device according to this embodiment can have the functions of a station device. Therefore, hereinafter, when a communication device is simply referred to as a communication device, the communication device can refer to both a station device and an access point device.

[0023] 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.

[0024] 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.

[0025] 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.

[0026] 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.

[0027] 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.

[0028] 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.

[0029] 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 (Figure 8). In addition, multiple MSDUs can be aggregated as an aggregated MSDU (A-MSDU).

[0030] 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.

[0031] The Ack may include a Block Ack, which is capable of notifying completion of reception of multiple MPDUs.

[0032] 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.

[0033] 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.

[0034] 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.

[0035] 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.

[0036] 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 by each device based on the power of a signal actually received (received power level) is called physical carrier sense (physical CS). The CCA level is also called a carrier sense level (CS level) or a CCA threshold (CCA threshold: CCAT). When a signal of CCA level or higher is detected, the base station device and the terminal device start an operation of demodulating at least a PHY layer signal.

[0037] 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.

[0038] 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.

[0039] Next, the details of frame reception will be described. 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).

[0040] 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.

[0041] 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.

[0042] 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.

[0043] The communication period by PCF includes a non-period (CFP: Contention free period) and a contention period (CP: Contention period). 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. Note that the PIFS is used for transmitting the beacon frame broadcast at the start of PCF transmission, and it is transmitted without waiting for the CW. The terminal device that receives the beacon frame sets the CFP period described in the beacon frame to the NAV. After that, 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 period, no packet collisions occur within the same BSS, so each terminal device does not take the random backoff time used in DCF.

[0044] 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.

[0045] 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.

[0046] 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.

[0047] 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.

[0048] 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.

[0049] 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.

[0050] 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.

[0051] 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.

[0052] 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.

[0053] 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.

[0054] 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.

[0055] 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.

[0056] FIG. 3 is a diagram showing an example of L-SIG Duration in L-SIG TXOP Protection. DATA (frame, payload, data, etc.) is composed of a MAC frame and a part or both of the PLCP header. Also, BA is Block Ack or Ack. PPDU includes L-STF, L-LTF, and L-SIG, and can further include any one or more of DATA, BA, RTS, and CTS. In the example shown in FIG. 3, L-SIG TXOP Protection using RTS / CTS is shown, but CTS-to-Self may also be used. Here, MAC Duration is a period indicated by the value of the Duration / ID field. Also, the Initiator can transmit a CF_End frame to notify the end of the L-SIG TXOP Protection period.

[0057] 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.

[0058] 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.

[0059] 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.

[0060] Ack and BA can also be called responses (response frames). In addition, a probe response, an authentication response, and a connection response can also be called responses. [1. First embodiment]

[0061] FIG. 5 is a diagram showing an example of a wireless communication system according to the present embodiment. The wireless communication system 3-1 includes a wireless communication device 1-1 and wireless communication devices 2-1 to 2-3. The wireless communication device 1-1 is also referred to as a base station device 1-1, and the wireless communication devices 2-1 to 2-3 are also referred to as terminal devices 2-1 to 3. The wireless communication devices 2-1 to 2-3 and the terminal devices 2-1 to 2-3 are also referred to as a wireless communication device 2A and a terminal device 2A, as devices connected to the wireless communication device 1-1. The wireless communication device 1-1 and the wireless communication device 2A are wirelessly connected, and are in a state in which they can transmit and receive PPDUs to each other. The wireless communication system according to the present embodiment may include a wireless communication system 3-2 in addition to the wireless communication system 3-1. The wireless communication system 3-2 includes a wireless communication device 1-2 and wireless communication devices 2-4 to 6. The wireless communication device 1-2 is also referred to as a base station device 1-2, and the wireless communication devices 2-4 to 6 are also referred to as terminal devices 2-4 to 6. Moreover, the wireless communication devices 2-4 to 2-6 and the terminal devices 2-4 to 2-6 are also referred to as the wireless communication device 2B and the terminal device 2B as devices connected to the 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. The ESS indicates a service set forming a LAN (Local Area Network). In other words, the wireless communication devices belonging to the same ESS can be regarded as belonging to the same network from the upper layer. The BSSs are also coupled via a DS (Distribution System) to form an ESS. Each of the wireless communication systems 3-1 and 3-2 can further include a plurality of wireless communication devices.

[0062] In the following description of FIG. 5, it is assumed that a signal transmitted by the wireless communication device 2A reaches the wireless communication device 1-1 and the wireless communication device 2B, but does not reach the wireless communication device 1-2. In other words, when the wireless communication device 2A transmits a signal using a certain channel, the wireless communication device 1-1 and the wireless communication device 2B determine that the channel is busy, while the wireless communication device 1-2 determines that the channel is idle. Also, it is assumed that a signal transmitted by the wireless communication device 2B reaches the wireless transmission device 1-2 and the wireless communication device 2A, but does not reach the wireless communication device 1-1. In other words, when the wireless communication device 2B transmits a signal using a certain channel, the wireless communication device 1-2 and the wireless communication device 2A determine that the channel is busy, while the wireless communication device 1-1 determines that the channel is idle.

[0063] A multi-link device (MLD) is a device capable of multi-link communication, and an access point device that supports MLD is called an MLD access point device, and a station device that supports MLD is called an MLD station device. Also, MLD access point devices and MLD station devices are collectively called MLD wireless communication devices. In this embodiment, the wireless communication devices 1-1, 1-2, 2A, and 2B described above are described as MLD wireless communication devices, but in actual operation, all wireless communication devices in a wireless communication system do not need to support MLD.

[0064] The MLD access point device 20000-1 and the MLD station device 30000-1 will be described with reference to Fig. 9. The MLD wireless communication device is composed of a plurality of sub-wireless communication devices corresponding to the frequency bands (or channels, or sub-channels) of each link (also called physical layer link) constituting the multi-link. Fig. 9 shows an example in which the MLD access point device 20000-1 is composed of three sub-wireless communication devices, in this case three sub-access point devices (20000-2, 200000-3, 20000-4), but the number of sub-access point devices is any number equal to or greater than two. Similarly, Fig. 9 shows an example in which the MLD station device 30000-1 is composed of three sub-wireless communication devices, in this case three substation devices (30000-2, 300000-3, 30000-4), but the number of substation devices is any number equal to or greater than two. The sub-wireless communication device (sub-access point device, sub-station device, etc.) may be configured as a part of the circuitry within the wireless communication device, and may be called a sub-wireless communication unit (sub-access point unit, sub-station unit).

[0065] In Fig. 9, for the sake of explanation, a plurality of sub-wireless communication devices are logically shown as separate blocks (squares). It may be physically configured as one wireless communication device. Alternatively, it may be physically configured as separate sub-wireless communication devices, in which case each sub-access point device transmits and receives necessary information via connections 9-1 and 9-2, and each substation device transmits and receives necessary information via connections 9-3 and 9-4. In this embodiment, the former case is mainly assumed, that is, it is physically configured as one wireless communication device (10000-1), and the configuration will be described later with reference to Figs. 6 and 7.

[0066] The number of sub-access point devices included in one MLD access point device and the number of substation devices included in one MLD station device vary according to the grade, class, and capabilities of each MLD wireless communication device. The higher the grade, class, and capabilities of an MLD wireless communication device, the greater the number of sub-wireless communication devices (sub-access point devices, substation devices) it may have. In other words, the number of sub-wireless communication devices (sub-access point devices, substation devices) possessed by each MLD wireless communication device located within one wireless communication system varies according to the grade, class, and capabilities, and the numbers do not have to be the same.

[0067] The substation device 30000-2 connects (associates) with the sub-access point device 20000-2 and establishes link 1. The substation device 30000-3 connects (associates) with the sub-access point device 20000-3 and establishes link 2. The substation device 30000-4 connects (associates) with the sub-access point device 20000-4 and establishes link 3. In the description of this embodiment, the number of links constituting the multi-link is three, but this is not limited to this and may be any number. In the description of this embodiment, the carrier frequency of link 1 is 2.4 GHz band, the carrier frequency of link 2 is 5 GHz band, and the carrier frequency of link 3 is 6 GHz band. However, the frequency used by each link can be arbitrarily set from the 2.4 GHz band, 5 GHz band, 6 GHz band, 60 GHz band, and other frequency bands, channels, and sub-channels supported by the wireless communication system, and may change according to the laws and regulations of each country.

[0068] 6 is a diagram showing an example of the device configuration of wireless communication device 10000-1. Wireless communication device 10000-1 includes upper layer processing unit (upper layer processing step) 10001-1, autonomous distributed control unit (autonomous distributed control step) 10002-1, transmission unit (transmission step) 10003-1, reception unit (reception step) 10004-1, and antenna unit 10005-1.

[0069] The upper layer processing unit 10001-1 processes information handled within the wireless communication device itself (information related to transmitted frames, MIB (Management Information Base), etc.) and frames received from other wireless communication devices, for layers higher than the physical layer, such as the MAC layer and LLC layer. The multilink control unit 10001a-1 may be included in the upper layer processing unit 10001-1, or may be independent.

[0070] The upper layer processing unit 10001-1 can notify the autonomous distributed control unit 10002-1 of information related to frames and traffic being transmitted to a wireless medium. The information may be, for example, control information included in a management frame such as a beacon, or measurement information reported by another wireless communication device to the wireless communication device itself. Furthermore, the information may be control information included in a management frame or a control frame without limiting the destination (it may be addressed to the device itself, may be addressed to another device, or may be broadcast or multicast).

[0071] 7 is a diagram showing an example of the device configuration of the autonomous distributed control unit 10002-1. The control unit 10002-1 includes a CCA unit (CCA step) 10002a-1, a backoff unit (backoff step) 10002b-1, a transmission decision unit (transmission decision step) 10002c-1, and a reception decision unit (reception decision step) 10002d-1.

[0072] The CCA unit 10002a-1 can use either or both of information on the power of a signal received via a wireless resource and information on the received signal (including information after decoding) notified from the receiving unit 10004-1 to perform a state determination of the wireless resource (including a determination of whether the wireless resource is busy or idle). The CCA unit 10002a-1 can notify the backoff unit 10002b-1 and the transmission determination unit 10002c-1 of the state determination information of the wireless resource.

[0073] The backoff unit 10002b-1 can perform backoff using wireless resource state determination information. The backoff unit 10002b-1 generates a CW and has a countdown function. For example, when the wireless resource state determination information indicates idle, the backoff unit 10002b-1 can execute a CW countdown, and when the wireless resource state determination information indicates busy, the backoff unit 10002b-1 can stop the CW countdown. The backoff unit 10002b-1 can notify the transmission determination unit 10002c-1 of the CW value.

[0074] The transmission decision unit 10002c-1 makes a transmission decision using either or both of the wireless resource status decision information and the CW value. For example, when the wireless resource status decision information indicates "idle" and the CW value is 0, the transmission decision unit 10003-1 can be notified of the transmission decision information. Also, when the wireless resource status decision information indicates "idle," the transmission decision unit 10003-1 can be notified of the transmission decision information.

[0075] The transmitting unit 10003-1 includes a physical layer frame generating unit (physical layer frame generating step) 10003a-1 and a wireless transmitting unit (wireless transmitting step) 10003b-1. The physical layer frame generating unit 10003a-1 has a function of generating a physical layer frame (PPDU) based on transmission decision information notified from the transmission decision unit 10002c-1. The physical layer frame generating unit 10003a-1 performs error correction coding, modulation, precoding filter multiplication, etc. on the transmission frame sent from the upper layer. The physical layer frame generating unit 10003a-1 notifies the wireless transmitting unit 10003b-1 of the generated physical layer frame.

[0076] The reception judgment unit 10002d-1 can instruct the reception unit 10004-1 to receive. A station device in a power management mode (sleep mode, power save mode) normally receives management frames such as beacons intermittently. From information contained in a beacon that the reception unit 10004-1 notifies the autonomous distributed control unit 10002-1, it can be determined whether or not the access point device is buffering a frame addressed to the station device itself. If the access point device is buffering a frame addressed to the station device itself, the reception judgment unit 10002d-1 instructs the reception unit 10004-1 to receive.

[0077] The operation of a station device in the power management mode will be described in detail. A station device in the power management mode usually receives management frames such as beacons intermittently. A beacon contains various pieces of information in IEs (Information Elements, also simply called elements or elements). One of these, the Traffic Indication Map (TIM) IE (Fig. 11), indicates whether or not the access point device is buffering (accumulating, suspending transmission) frames addressed to the station device in the power management mode. In the example of Fig. 11, 16 bits are assigned to the partial virtual bitmap, and each bit indicates whether or not the access point device is buffering frames addressed to each AID (addressed to each station device). If the bit is set, it indicates that the frame is buffered, and if the bit is reset, it indicates that the frame is not buffered. Note that setting the bit to "1" is usually defined as setting, and setting the bit to "0" is defined as reset. Conversely, it may be defined with different values, such as setting the bit to "0" and setting the bit to "1" as reset.

[0078] The Bitmap Control field includes information on the Bitmap Offset. For example, if the Bitmap Offset value is 0, each bit in the Partial Virtual Bitmap field indicates the presence or absence of buffered frames of station devices corresponding to AID1 to AID16 in order from the left. In the case of FIG. 11, the bits corresponding to AID1, AID4, and AID8 are set, which means that the access point device is buffering frames addressed to AID1, AID4, and AID8. If the Bitmap Offset value is "1" (for simplicity, in this explanation, only one byte of offset is given, but depending on the specifications, it may be multiplied by a constant, such as by applying an offset of two bytes. Also, the offset in bits may be indicated), each bit in the Partial Virtual Bitmap field indicates the presence or absence of buffered frames of station devices corresponding to AID9 to AID24 in order from the left. In the case of FIG. 11, the bits corresponding to AID9, AID12, and AID16 are set, which means that the access point device is buffering frames addressed to AID9, AID12, and AID16. In this way, even if the number of bits allocated to the Partial Virtual Bitmap field is limited, by adjusting the Bitmap Offset value, more AIDs can be expressed, that is, more station devices can be notified of the presence or absence of frames buffered in the access point device.

[0079] The physical layer frame generator performs error correction coding on the information bits transferred from the MAC layer, but the unit (coding block length) for performing error correction coding is not limited to any particular one. For example, the physical layer frame generator can divide the information bit sequence transferred from the MAC layer into information bit sequences of a predetermined length, perform error correction coding on each of them, and generate a plurality of coding blocks. When forming the coding blocks, it is also possible to insert dummy bits into the information bit sequence transferred from the MAC layer.

[0080] The frame generated by the physical layer frame generator 10003a-1 includes control information. The control information includes information indicating in which RU (here, RU includes both frequency resources and spatial resources) data addressed to each wireless communication device is allocated. The frame generated by the physical layer frame generator 10003a-1 also includes a trigger frame that instructs the wireless communication device, which is the destination terminal, to transmit a frame. The trigger frame includes information indicating the RU to be used when the wireless communication device instructed to transmit the frame transmits the frame.

[0081] The wireless transmission unit 10003b-1 converts the physical layer frame generated by the physical layer frame generation unit 10003a-1 into a radio frequency (RF) band signal to generate a radio frequency signal. The processing performed by the wireless transmission unit 10003b-1 includes digital-to-analog conversion, filtering, frequency conversion from the baseband band to the RF band, and the like.

[0082] The receiving section 10004-1 includes a wireless receiving section (wireless receiving step) 10004a-1, a signal demodulating section (signal demodulating step) 10004b-1, and a reception quality measuring section (reception quality measuring step) 10004c-1.

[0083] The reception quality measurement unit 10004c-1 generates information about reception quality from the RF band signal received by the antenna unit 10005-1. The information about the signal quality includes a reception power level and an SNR (Signal to Noise Ratio). The reception unit 10004-1 may notify the autonomous distributed control unit 10002-1 (particularly, the CCA unit 10002a-1) and the upper layer processing unit 10001-1 (particularly, the multi-link control unit 10001a-1) of the information about the reception quality and the information about the received signal. The reception unit 10004-1 may also notify the autonomous distributed control unit 10002-1 and the upper layer processing unit 10001-1 of other information.

[0084] The wireless receiver 10004a-1 has a function of converting an RF signal received by the antenna unit 10005-1 into a baseband signal and generating a physical layer signal (e.g., a physical layer frame). The processing performed by the wireless receiver 10004a-1 includes frequency conversion from the RF band to the baseband, filtering, and analog-to-digital conversion.

[0085] The signal demodulation unit 10004b-1 has a function of demodulating the physical layer signal generated by the wireless receiving unit 10004a-1. The processing performed by the signal demodulation unit 10004b-1 includes channel equalization, demapping, error correction decoding, and the like. The signal demodulation unit 10004b-1 can extract, for example, information contained in the 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 10004b-1 can notify the extracted information to the upper layer processing unit 10001-1. The signal demodulation unit 10004b-1 can extract any one or all of the information contained in the physical layer header, information contained in the MAC header, and information contained in the transmission frame.

[0086] The antenna unit 10005-1 has a function of transmitting the radio frequency signal generated by the radio transmission unit 10003b-1 into a radio space, and also has a function of receiving the radio frequency signal and passing it to the radio reception unit 10004a-1.

[0087] The multi-link control unit 10001a-1 receives information on the reception quality of each link (each frequency band, each channel, each sub-channel) from the reception quality measurement unit 10004c-1, judges the quality of each link, and decides which link to select and use to configure the multi-link. The information on the reception quality includes, but is not limited to, the reception power level and SNR (Signal to Noise Ratio).

[0088] The wireless communication device 10000-1 can cause the wireless communication devices around the wireless communication device to set NAV for only that period by describing information indicating the period during which the wireless communication device uses the wireless medium in the PHY header or MAC header of the frame to be transmitted. For example, the wireless communication device 10000-1 can describe information indicating that period in the Duration / ID field or Length field of the frame to be transmitted. The NAV period set in the wireless communication devices around the wireless communication device is called the TXOP period (or simply TXOP) acquired by the wireless communication device 10000-1. The wireless communication device 10000-1 that has acquired the TXOP is called a TXOP acquirer (TXOP holder). The frame type of the frame transmitted by the wireless communication device 10000-1 to acquire the TXOP is not limited to any particular type, and may be a control frame (for example, an RTS frame or a CTS-to-self frame) or a data frame.

[0089] The wireless communication device 10000-1, which is a TXOP holder, can transmit frames to wireless communication devices other than the wireless communication device itself during the TXOP. When the wireless communication device 1-1 is a TXOP holder, the wireless communication device 1-1 can transmit frames to the wireless communication device 2A during the TXOP period. Furthermore, the wireless communication device 1-1 can instruct the wireless communication device 2A to transmit a frame addressed to the wireless communication device 1-1 during the TXOP period. The wireless communication device 1-1 can transmit a trigger frame including information instructing the wireless communication device 2A to transmit a frame addressed to the wireless communication device 1-1 during the TXOP period.

[0090] The wireless communication device 1-1 may reserve a TXOP for all communication bands (e.g., Operation bandwidth) over which frames may be transmitted, or may reserve a TXOP for a specific communication band (Band), such as a communication band (e.g., Transmission bandwidth) over which frames will actually be transmitted.

[0091] The wireless communication device that instructs the wireless communication device 1-1 to transmit a frame during the period of the TXOP acquired by the wireless communication device 1-1 is not necessarily limited to the wireless communication device connected to the wireless communication device itself. For example, the wireless communication device can instruct a wireless communication device that is not connected to the wireless communication device itself to transmit a frame in order to make a wireless communication device in the vicinity of the wireless communication device itself transmit a management frame such as a Reassociation frame or a control frame such as an RTS / CTS frame.

[0092] In addition, we will explain TXOP in EDCA, which is a data transmission method different from DCF. The IEEE802.11e standard is related to EDCA, and specifies TXOP from the viewpoint of QoS (Quality of Service) guarantee for various services such as video transmission and VoIP. Services are roughly classified into four access categories: VO (VOice), VI (VIdeo), BE (Best Effort), and BK (Background). Generally, the order of priority is VO, VI, BE, and BK. Each access category has parameters such as the minimum value of CW, CWmin, the maximum value, AIFS (Arbitration IFS), which is a type of IFS, and TXOP limit, which is the upper limit of transmission opportunities, and the values ​​are set to give a difference in priority. For example, the CWmin, CWmax, and AIFS of VO, which has the highest priority for voice transmission, can be set to relatively small values ​​compared to other access categories, enabling data transmission with priority over other access categories. For example, in a VI where the amount of data transmitted is relatively large for video transmission, by setting the TXOP limit large, it is possible to secure a longer transmission opportunity than in other access categories.In this way, the values ​​of the four parameters for each access category are adjusted to guarantee QoS according to various services.

[0093] In this embodiment, the signal demodulator of the station device can perform decoding processing and error detection on the received signal in the physical layer. Here, the decoding processing includes decoding processing on the error correction code applied to the received signal. Here, the error detection includes error detection using an error detection code (e.g., a cyclic redundancy check (CRC) code) that is previously added to the received signal, and error detection using an error correction code that originally has an error detection function (e.g., a low-density parity check code (LDPC)). The decoding processing in the physical layer can be applied to each coding block.

[0094] The upper layer processing unit transfers the result of decoding the physical layer in the signal demodulation unit to the MAC layer. The MAC layer restores the MAC layer signal from the transferred result of decoding the physical layer. The MAC layer then performs error detection to determine whether the MAC layer signal transmitted by the station device that is the transmission source of the received frame has been correctly restored.

[0095] 10 shows an outline of the procedure related to the multilink of this embodiment, using an MLD wireless communication device 1-1 (hereinafter also referred to as an MLD access point device) and an MLD wireless communication device 2-1 (hereinafter also referred to as an MLD station device) as examples of wireless communication devices. In this case, the MLD wireless communication device 2-1 that transmits a multilink establishment request 10-1 is referred to as a multilink initiator, and transmits it to the MLD wireless communication device 1-1. The multilink establishment request may include control information such as the multilink capability information (Capability information) of the wireless communication device itself and information on the multilink operation mode to be established. The multilink establishment request 10-1 may be included in a management frame such as an Association Request frame. The multilink initiator may be the MLD wireless communication device 1-1, not the MLD wireless communication device 2-1. The multi-link establishment request may be transmitted independently for each link, or may be transmitted for one of the links constituting the multi-link.

[0096] The MLD wireless communication device 1-1 that has received the multi-link establishment request transmits a multi-link establishment response to the MLD wireless communication device 2-1. The multi-link establishment response 10-2 may include control information such as multi-link capability information of the wireless communication device itself, establishment status information indicating whether the multi-link establishment has been successful, a multi-link ID used to identify the multi-link, and multi-link operation mode information. The multi-link operation mode information included in the multi-link establishment response may be finally determined based on the multi-link operation mode included in the multi-link establishment request received from the MLD wireless communication device 2-1 and the multi-link operation mode that the wireless communication device 1-1 can provide. The multi-link operation mode information may include information on the frequency band (or channel, or sub-channel) used in the established multi-link communication. If the establishment status information indicates success, a multi-link is established according to the multi-link operation mode information included in the multi-link establishment response. If the establishment status information indicates failure, the multi-link cannot be established. The multi-link establishment response 10-2 may be included in a management frame such as an Association Response frame.

[0097] After the establishment of a multi-link (including association through the exchange of a multi-link establishment request and response), an MLD station device that supports the power management mode transitions to a mode in which it intermittently receives management frames (including some action frames, etc., 10-4, 10-5, 10-6) such as beacons transmitted by the MLD station device, and operates in a power-saving manner. The management frames 10-4, 10-5, 10-6 may contain information notifying whether or not the MLD access point device is buffering (accumulating, suspending transmission) frames addressed to the MLD station device in the power management mode. Specifically, in addition to the TIM IE mentioned above, there are examples such as an AID Bitmap Element (AID bitmap information) that has a role similar to that of the TIM IE for multi-link, and a Multi-Link Traffic Indication Element (multi-link traffic indication information, multi-link traffic information) that contains information specifying (or recommending) the link to be used by each MLD station device. An MLD station device may detect and determine whether or not a frame addressed to the MLD station device itself is buffered (stored) in the connected MLD access point device from the TIM IE, AID Bitmap Element, Multi-Link Traffic Indication Element, etc. Note that the AID Bitmap element may be substituted with the TIM IE, so the embodiment will still be valid if the AID Bitmap element is replaced with the TIM IE in the following description.

[0098] 10 illustrates an example of a sequence in which an MLD station device supporting the Power Management mode receives and retrieves frames buffered by an MLD access point device. The MLD station device switches to Active mode (transmitting and receiving mode) to receive frames 10-4, 10-5, and 10-6 intermittently. When the MLD station device receives frames 10-4 and 10-5 and checks the AID Bitmap Element and Multi-Link Traffic Indication Element to detect that the MLD access point device is not buffering frames addressed to the MLD station device itself, it returns to Power Management mode (Power Save mode, sleep mode). When the MLD station device receives a management frame 10-6 and checks the AID Bitmap Element and Multi-Link Traffic Indication Element to detect that the MLD access point device is buffering frames addressed to the MLD station device itself, it transmits a control frame 10-7 to the MLD station device. The MLD access point device that receives the control frame 10-7 detects that the MLD station device is in active mode and transmits the buffered frame 10-8 (or multiple frames) to the MLD station device. When the access point device has completed receiving the buffered frame 10-8, the MLD station device transitions from Active mode to Power Management mode.

[0099] An example of the AID Bitmap Element and Multi-Link Traffic Indication Element in a multi-link connection is described in Fig. 12. In the description in Fig. 12, an example is described in which an MLD access point device supports 12 links from link 1 to link 12, multiple MLD station devices are connected, and the MLD access point device checks the contents of the AID Bitmap Element and Multi-Link Traffic Indication Element contained in a management frame (beacon, action frame, etc.) received on link 2 to determine whether or not the MLD access point device is buffering a frame addressed to each MLD station device. In reality, the number of links may be a value other than the above-mentioned 12 links, and varies depending on the capabilities of the MLD access point device and MLD station device. Also, a management frame including the AID Bitmap Element and Multi-Link Traffic Indication Element may be received on a link other than link 2. Also, a non-MLD wireless communication device other than an MLD station device may be connected to the MLD access point device.

[0100] In Fig. 12, the value of the Bitmap Offset of the AID Bitmap element is set to 0, and 16 bits are allocated to the Partial AID Bitmap, so that AID1 to AID16 can be expressed. Here, each bit in the Partial AID Bitmap (which has the same role as the Partial Virtual Bitmap described above. From here on, where "Partial AID Bitmap" is written, the embodiment will still be valid even if it is read as "Partial Virtual Bitmap") field indicates, in order from the left, whether or not frames addressed to station devices corresponding to AID1 to AID16 are buffered. In this example, the bits corresponding to AID4, AID8, AID9, and AID11 are set, so that the MLD access point device buffers frames addressed to MLD station devices corresponding to AID4, AID8, AID9, and AID11.

[0101] The MLD access point device can negotiate in advance with each MLD station device which link to use to transmit buffered frames, or the MLD access point device can present each MLD station device with the link it recommends to use.

[0102] TID-to-Link Mapping is an example of a pre-negotiation mechanism. In the default operation, there is no special association between the value of a TID (Traffic ID) of a frame and the link that transmits the frame, and any frame of TID may be transmitted on any link, which is called default TID-to-Link mapping. On the other hand, a frame with a specific TID can be mapped by pre-negotiating to transmit on a specific link, and this procedure is called TID-to-Link Mapping, and as a result, a non-default TID-to-Link Mapping is formed. For example, since frames classified as Voice AC (Access Category) cannot tolerate large delays, TID-to-Link Mapping may be used to map frames of the corresponding TID to links with less interference and less congestion.

[0103] The mechanism for presenting each MLD station device with a link recommended for use is called Link Recommendation. For MLD station devices operating with default TID-to-Link mapping, the link recommended for use may be presented depending on the situation. Also, for MLD station devices operating with non-default TID-to-Link Mapping, the link recommended for use may be presented depending on the situation (especially applicable when one TID is mapped to multiple links and one of those links is recommended).

[0104] In the example of Figure 12, in an MLD station device with AID4, links 1 to 3 are enabled and available for use, and frames are buffered in links 2 and 3 (or their use is recommended). In an MLD station device with AID8, links 4 to 12 are enabled, and frames are buffered in link 11 (or their use is recommended). In an MLD station device with AID9, links 2 and 3 are enabled, and frames are buffered in link 2 (or their use is recommended). In an MLD station device with AID11, links 2 and 3 are enabled, and frames are buffered in link 3 (or their use is recommended).

[0105] The Multi-link Traffic Indication Element specifies which link each MLD station device is specified (or recommended) to use by the MLD access point device. The Multi-link Traffic Indication Element is composed of a Bitmap Size field, a Link ID Offset field (link ID offset information, link offset information), and multiple Per-Link Traffic Indication Bitmap fields. However, the Multi-link Traffic Indication Element does not have to include any of the above fields, and may include an AID offset field as a separate field. The AID Offset has the same role as the Bitmap Offset in the Partial AID Bitmap, and its specific operation will be described later.

[0106] The Bitmap Size field may specify the number of bits to be allocated to each Per-Link Traffic Indication Bitmap, and may be link number information indicating the number of links represented in each Per-Link Traffic Indication Bitmap field. The Bitmap Size field may include information indicating the number of Per-Link Traffic Indication Bitmaps. The Bitmap Size field may include information on the number of bytes or bits to be allocated to the Per-Link Traffic Indication Bitmap. In this example, it is specified that 10 bits are allocated to each Per-Link Traffic Indication Bitmap. The Bitmap Size field may include information such as "4 Per-Link Indication Bitmaps are included" or "10x4 = 40 bits (5 bytes) are allocated to the Per-Link Traffic Indication Bitmap."

[0107] The Link ID Offset field stores a value that specifies the start number (offset value) of the link numbers indicated by each Per-Link Traffic Indication Bitmap. In this example, it is specified to start from link 2, that is, the 10 bits that make up each Per-Link Traffic Indication Bitmap indicate links 2 to 11, respectively.

[0108] In FIG. 12, Per-Link Traffic Indication Bitmap 1 stores "1", "1", "0", "0", "0", "0", "0", "0", "0", indicating that the use of Link 2 and Link 3 has been notified. Per-Link Traffic Indication Bitmap 2 stores "0", "0", "0", "0", "0", "0", "0", "0", "1", indicating that the use of Link 11 has been notified. Per-Link Traffic Indication Bitmap 3 stores "1", "0", "0", "0", "0", "0", "0", "0", "0", indicating that the use of Link 2 has been notified. Per-Link Traffic Indication Bitmap 4 stores "0", "1", "0", "0", "0", "0", "0", "0", "0", "0", indicating that the use of Link 3 has been notified.

[0109] The operation when an offset amount is specified in the AID Offset field in the Multi-Link Traffic Indication Element will be described. For example, when 1 byte (8 bits) is set as the AID Offset, the Per-Link Traffic Indication for the MLD station device corresponding to the AID after AID9 at the position offset (shifted) by 1 byte (8 bits) in the Partial AID Bitmap, that is, the position skipping AID1 to AID8, is included in the Multi-Link Traffic Indication Element. That is, in FIG. 12, it is possible to configure a Multi-Link Traffic Indication Element that does not include Per-Link Traffic Indication 1 for AID5 and Per-Link Traffic Indication 2 for AID8, but includes Per-Link Traffic Indication 3 for AID9 and Per-Link Traffic Indication 4 for AID11.

[0110] In the example of FIG. 12, among the four MLD station devices with bits set in the Partial AID Bitmap, the MLD station devices corresponding to AID4, AID9, and AID11 are specified (or recommended) to use lower link numbers, while the MLD station device corresponding to AID8 is specified (or recommended) to use higher link numbers. The Link ID Offset field is intended to reduce the amount of bits consumed by each Per-Link Traffic Indication. However, even if it is specified to start from link 2 as in this example, it is necessary to express links 2 to 11 in the Per-Link Traffic Indication Bitmap field due to the influence of AID9, which is specified (or recommended) to use higher link numbers, and therefore each Per-Link Traffic Indication Bitmap field consumes a large amount of bit resources, 10 bits. As a solution to this problem, the number of bits consumed by each Per-Link Traffic Indication Bitmap field may be reduced by storing multiple Bitmap Size fields and Link ID Offset fields in one Multi-Link Traffic Indication Element, and this will be explained using FIG. 13.

[0111] The example in Figure 13 uses a combination of three Bitmap Size fields and Link ID Offset fields in a Multi-Link Traffic Indication Element. The first combination of Link ID Offset field and Bitmap Size field indicates a notification to the MLD station device corresponding to AID4. Here, the Bitmap Size field specifies that each Per-Link Traffic Indication Bitmap consists of 2 bits, and that the number of Per-Link Traffic Indication Bitmaps included is 1. The Link ID Offset field is set to "1" to specify that the links indicated by each Per-Link Traffic Indication Bitmap start from link 2. Per-Link Traffic Indication Bitmap 1 stores "1" and "1", indicating that the MLD station device corresponding to AID4 has been notified of the use of links 2 and 3.

[0112] The combination of the second Link ID Offset field and Bitmap Size field indicates a notification to the MLD station equipment corresponding to AID8. Bitmap Size specifies that each Per-Link Traffic Indication Bitmap consists of 2 bits, and that the number of Per-Link Traffic Indication Bitmaps included is 1. The Link ID Offset field is set to "10", specifying that the links indicated by each Per-Link Traffic Indication Bitmap start from link 11. Per-Link Traffic Indication Bitmap2 stores "1" and "0", indicating that the MLD station equipment corresponding to AID8 has been notified of the use of link 11.

[0113] The third combination of Link ID Offset field and Bitmap Size field indicates notification to the MLD station equipment corresponding to AID9 and AID11. Bitmap Size specifies that each Per-Link Traffic Indication Bitmap consists of 2 bits, and that the number of Per-Link Traffic Indication Bitmaps included is 2. The Link ID Offset field is set to "1" to specify that the links indicated by each Per-Link Traffic Indication Bitmap start from link 2. Per-Link Traffic Indication Bitmap 3 stores "1" and "0", indicating that the MLD station equipment corresponding to AID9 has been notified that link 2 will be used. Per-Link Traffic Indication Bitmap 4 stores "0" and "1", indicating that the MLD station equipment corresponding to AID11 has been notified that link 3 will be used.

[0114] 13 shows an example in which the first combination of Bitmap Size field and Link ID Offset field specifies (or recommends) a link to be used by an MLD station device corresponding to one AID (AID4 in this example), the second combination of Bitmap Size field and Link ID Offset field specifies (or recommends) a link to be used by an MLD station device corresponding to one AID (AID8 in this example), and the third combination of Bitmap Size field and Link ID Offset field specifies (or recommends) a link to be used by an MLD station device corresponding to two AIDs (AID9, AID11 in this example). The number of AIDs specified (or recommended) by each combination of Bitmap Size field and Link ID Offset field can be freely changed by the value specified in the Bitmap Size field. In other words, a combination of Bitmap Size field and Link ID Offset field may be added for each AID at the smallest unit, or a combination of Bitmap Size field and Link ID Offset field may be shared by multiple AIDs.

[0115] The combination of the Bitmap Size field and the Link ID Offset field may be divided and described in multiple Information Elements. In the explanation of Fig. 13, examples have been shown in which AID4, AID9, and AID11 have a Link ID Offset of "1", and AID8 has a Link ID Offset of "10". These are representative examples of cases in which the use of a lower link number is designated (or recommended), and a higher link number is designated (or recommended), respectively. As a modification of the frame configuration shown in Fig. 13, Fig. 14 shows an example in which the Link ID Offset is classified into two, "1" and "10", and described in separate Information Elements.

[0116] In the example of FIG. 14, the AID for which the link to be used is notified by the Multi-Link Traffic Indication Element 14-12 with the link ID offset of "1" is notified by the AID Bitmap Element 14-11. The AID for which the link to be used is notified by the Multi-Link Traffic Indication Element 14-22 with the link ID offset of "10" is notified by the AID Bitmap Element 14-21. As the combination of the Bitmap Size field and the Link ID Offset field is described in separate Information Elements, the AID Bitmap Element is also divided into AID Bitmap elements 14-12 and 14-22 linked to the Multi-Link Traffic Indication Elements 14-12 and 14-22, respectively. This is merely an example, and if it is possible to determine which AID each Per-Link Traffic Indication Element included in each Multi-Link Traffic Indication Element corresponds to, there is no need to prepare multiple AID Bitmap Elements.

[0117] The association between AID Bitmap Element 14-11 and Multi-Link Traffic Indication Element 14-12, and the association between AID Bitmap Element 14-21 and Multi-Link Traffic Indication Element 14-22 may follow the order in which these Information Elements are arranged in the management frame (beacon, action frame, etc.) in which they are placed. For example, if the AID Bitmap Elements are arranged in the order of 14-11 and 14-21, and the Multi-Link Traffic Indication Elements are arranged in the order of 14-12 and 14-22 in the management frame, 14-11 and 14-12 are associated, and 14-21 and 14-22 are associated. For example, if the AID Bitmap Elements are arranged in the order of 14-11 and 14-21 within the management frame, and the Multi-Link Traffic Indication Elements are arranged in the order of 14-22 and 14-12, then 14-11 and 14-22 are linked, and 14-21 and 14-12 are linked.

[0118] A field including a "linking identifier" for linking the AID Bitmap Element and the Multi-Link Traffic Indication Element may be placed in each of the AID Bitmap Element and the Multi-Link Traffic Indication Element. When the "linking identifier" of the AID Bitmap Element(X) matches the "linking identifier" of the Multi-Link Traffic Indication Element(Y), the AID Bitmap Element for the Multi-Link Traffic Indication Element(Y) is linked to the AID Bitmap Element(X). In other words, the link used by each MLD station device corresponding to the AID whose bit is set in the Partial AID Bitmap of the AID Bitmap Element(X) is notified by the Multi-Link Traffic Indication Element(Y).

[0119] In the combination 14-1 of AID Bitmap Element and Multi-Link Traffic Indication Element in FIG. 14, the bits corresponding to AID4, AID9, and AID11, which had Link ID Offset "1" in FIG. 13, are set in the Partial AID Bitmap of AID Bitmap Element 14-11, and the links used by the MLD station devices corresponding to these are notified by Multi-Link Traffic Indication Element 14-12. In this example, the Bitmap Size field contains information indicating that each Per-Link Traffic Indication Bitmap is composed of 2 bits. The Link ID Offset is set to "1" to specify that the links indicated by each Per-Link Traffic Indication Bitmap start from Link 2. Per-Link Traffic Indication Bitmap 1 stores "1" and "1", indicating that the MLD station device corresponding to AID4 has been notified of the use of Link 2 and Link 3. Per-Link Traffic Indication Bitmap 2 stores "1" and "0", indicating that the MLD station device corresponding to AID9 has been notified of the use of Link 2. Per-Link Traffic Indication Bitmap 3 stores "0" and "1", indicating that the MLD station device corresponding to AID 11 has been notified of the use of link 3.

[0120] In the combination 14-2 of AID Bitmap Element and Multi-Link Traffic Indication Element in FIG. 14, the bit corresponding to AID8, whose Link ID Offset was "10" in FIG. 13, is set in the Partial AID Bitmap of AID Bitmap Element 14-21, and the link used by the MLD station device corresponding to these is notified by Multi-link Traffic Indication Element 14-22. In this example, it is assumed that the Bitmap Size field contains information indicating that each Per-Link Traffic Indication Bitmap is composed of 2 bits. The Link ID Offset is set to "10" and the links indicated by each Per-Link Traffic Indication Bitmap are specified to start from link 11. Also, since "10" is not used as the Link ID Offset from AID9 onwards, the Partial AID Bitmap may contain only one byte indicating AID1 to AID8. "1" and "0" are stored in Per-Link Traffic Indication Bitmap 1, indicating that the use of link 11 has been notified to the MLD station device corresponding to AID8.

[0121] In the example shown in FIG. 14, there are two combinations of AID Bitmap Element and Multi-Link Traffic Indication Element, 14-1 and 14-2, but the number of combinations may be more than two.

[0122] Also, one of the combinations of a plurality of AID Bitmap Elements and Multi-Link Traffic Indication Elements may be set to represent all links supported by the MLD access point device. For example, if the number of links supported by the MLD access point device is 16, the Bitmap Size field may be set to specify the number of bits to be assigned to each Per-Link Traffic Indication Bitmap as "16", which corresponds to the total number of links, and the number of links represented in each Per-Link Traffic Indication Bitmap field may be set to link 1 to link 16.

[0123] In the first embodiment, as shown in Fig. 12 and Fig. 13, the Multi-Link Traffic Indication is composed of a Bitmap Size field, a Link ID Offset field, a plurality of Per-Link Traffic Indication Bitmap fields, an AID Offset field, etc. Also, it has been explained with reference to Fig. 13 that a combination of a plurality of Bitmap Size fields and Link ID Offset fields may be arranged in one Multi-Link Traffic Indication Element. Furthermore, it has been explained with reference to Fig. 14 that a combination of a Link ID Offset field and a Bitmap Size field may be divided and arranged in a plurality of Information Elements.

[0124] [2. Second embodiment] The configurations of the wireless communication system, the MLD access point device, and the MLD station device in the second embodiment are the same as those in the first embodiment, and may be combined with the first embodiment. In the second embodiment, the configuration of the Multi-link Traffic Indication Element is explained with reference to FIG. 15, which is composed of a Bitmap Size field, a Link ID Block field, and a plurality of Per-Link Traffic Indication Bitmap fields. However, the Multi-link Traffic Indication Element may not include any of the above-mentioned fields, or may include an AID offset field as another field. The method of using the AID Offset is the same as in the first embodiment. Also, as in the explanation using FIG. 13 in the first embodiment, a combination of a plurality of Bitmap Size fields and Link ID Block fields may be arranged in one Multi-Link Traffic Indication Element. Furthermore, as in the explanation using FIG. 14 in the first embodiment, a combination of the Bitmap Size field and the Link ID Block field may be divided and arranged in a plurality of Information Elements.

[0125] The Link ID Block will now be described. For example, when the MLD access point device supports 16 links, Link 1 to Link 16, the total links are divided into four, Link 1 to Link 4 are Link Block 1, Link 5 to Link 8 are Link Block 2, Link 9 to Link 12 are Link Block 3, and Link 13 to Link 16 are Link Block 4. In FIG. 15, the value of the Bitmap Offset of the AID Bitmap Element is 0, and 16 bits are assigned to the Partial AID Bitmap, so that AID1 to AID16 can be expressed. Here, each bit in the Partial AID Bitmap field (equivalent to the Partial Virtual Bitmap field) indicates whether or not frames addressed to MLD station devices corresponding to AID1 to AID16 are buffered in order from the left. In this example, the bits corresponding to AID4, AID9, and AID11 are set, which indicates that the MLD access point device is buffering frames addressed to MLD station devices corresponding to AID4, AID9, and AID11.

[0126] The MLD access point device notifies each MLD station device of which link it has been specified (or recommended) to use by using a Multi-link Traffic Indication Element. The Multi-link Traffic Indication Element may be composed of a Bitmap Size field, a Link ID Block field, and multiple Per-Link Traffic Indication Bitmap fields. The Multi-Link Traffic Indication Element may also include an AID Bitmap Offset and a Link ID Offset, and is used in the same manner as in the first embodiment.

[0127] The Link ID Block field stores a value that specifies the Link Block that each Per-Link Traffic Indication Bitmap points to. In this example, it is assumed that a value indicating Link Block 1 that points to links 1 to 4 is stored. In this case, the four bits that make up each Per-Link Traffic Indication Bitmap indicate links 1 to 4, respectively. If a value indicating Link Block 4 that points to links 13 to 16 is stored, the four bits that make up each Per-Link Traffic Indication Bitmap indicate links 13 to 16, respectively.

[0128] In Figure 15, Per-Link Traffic Indication Bitmap 1 stores "0", "1", "1", and "0", indicating that the use of Link 2 and Link 3 has been notified. Per-Link Traffic Indication Bitmap 2 stores "0", "1", "0", and "0", indicating that the use of Link 2 has been notified. Per-Link Traffic Indication Bitmap 3 stores "0", "1", "0", and "0", indicating that the use of Link 2 has been notified. Per-Link Traffic Indication Bitmap 4 stores "0", "0", "1", and "0", indicating that the use of Link 3 has been notified.

[0129] 15, dividing the total number of links, 16, into four, with links 1 to 4 in Link Block 1, links 5 to 8 in Link Block 2, links 9 to 12 in Link Block 3, and links 13 to 16 in Link Block 4, is merely an example. The total number of links may change depending on the capabilities of the MLD access point device, and the division number is not limited to four and may be another value.

[0130] Furthermore, there is no restriction to dividing it equally into four, and the size of each Link Block may be divided unequally in various ways, such as Link 1 to Link 8 being Link Block 1, Link 9 to 12 being Link Block 2, Link 13 to 15 being Link Block 3, and Link 16 being Link Block 4.

[0131] Also, each link may be included in a duplicated manner in different Link Blocks. For example, Link 1 and Link 5 may be included in multiple Link Blocks, Link Block 1 may be configured as Links 1 to 8, Link Block 2 may be configured as Link 1, Link 5, and Link 9, Link Block 3 may be configured as Link 1, Links 10 to 12, Link Block 4 may be configured as Links 13 to 16, etc. Any link may be included in a duplicated manner in each Link Block.

[0132] The link number included in each Link Block may be defined in a separately prepared table or in the MIB.

[0133] Based on this, we will explain the specific configuration of Link Block. The frequency bands and number of channels supported by Multi-Link are expected to increase in the future. Currently, the main frequency bands are 2.4GHz and 5GHz, but in the future, this will increase to 6GHz and beyond that to 45GHz and 60GHz. MLD station equipment will also be categorized (also called grade or class) depending on the purpose of use, and it is expected that there will be differences in the frequency bands that it supports.

[0134] For example, assume that 2.4 GHz is provided as link 1, 5 GHz-1 as link 2, 5 GHz-2 as link 3, 6 GHz-1 as link 4, 6 GHz-2 as link 5, 45 GHz-1 as link 6, 45 GHz-2 as link 7, 45 GHz-3 as link 8, 45 GHz-4 as link 9, 60 GHz-1 as link 10, 60 GHz-2 as link 11, 60 GHz-3 as link 12, and 60 GHz-4 as link 13.

[0135] The low-priced (low-grade) MLD station equipment G1 supports links 1 to 3 (supports frequency bands 2.4 GHz and 5 GHz), the higher-end model MLD station equipment G2 supports links 1 to 5 (supports frequency bands 2.4 GHz, 5 GHz and 6 GHz), the even higher-end model MLD station equipment G3 supports links 1 to 9 (supports frequency bands 2.4 GHz, 5 GHz, 6 GHz and 45 GHz), and the even higher-end model MLD station equipment G4 supports links 1 to 13 (supports frequency bands 2.4 GHz, 5 GHz, 6 GHz, 45 GHz and 60 GHz). In other words, the higher the price (grade), the more links are supported and the higher the frequency bands that may be supported.

[0136] The links supported by MLD station device G1 are classified and categorized as Link Block 1, those supported by MLD station device G2 as Link Block 2, those supported by MLD station device G3 as Link Block 3, and those supported by MLD station device G4 as Link Block 4. Information elements that notify the presence or absence of frames buffered by the MLD access point device can be used separately for each category (also called grade or class). With this method, in a situation where a large number of low-priced MLD station devices G1 and a small number of high-priced MLD station devices G4 are connected to an MLD access point device in a wireless system, the amount of bits consumed for MLD station device G1 in the AID Bitmap Element and Multi-Link Traffic Indication Element can be kept relatively small without being affected by MLD station device G4 supporting a large number of links.

[0137] Here, it has been explained that the products are categorized (also called grade or class) according to price range, etc., but this concept of Link Block is merely an example, and the criteria for categorization are not limited to this. Also, it is possible to enter a category (also called grade or class) number in the Link ID Block field, and define link numbers corresponding to each category number in a table, MIB, etc.

[0138] [3. Third embodiment] In the third embodiment, a method of notifying each MLD station device of which link it is specified (or recommended) to use, using a Link Bitmap Pattern, will be described with reference to Fig. 16. In this embodiment, the MLD access point device does not transmit an AID Bitmap Element to the MLD station device, but transmits only a Multi-Link Traffic Indication Element, thereby notifying each MLD station device of the link to be used. To supplement this, information equivalent to a Partial AID Bitmap (equivalent to a Partial Virtual Bitmap) contained in the AID Bitmap Element is placed in the Multi-Link Traffic Indication Element.

[0139] In this example, the value of the Bitmap Offset of the AID Bitmap Element is set to 0, and 16 bits are allocated to the Partial AID Bitmap, so that AID1 to AID16 can be expressed. Each bit in the Partial AID Bitmap field indicates, in order from the left, whether or not frames addressed to station devices corresponding to AID1 to AID16 are buffered. In this example, the bits corresponding to AID4, AID8, AID9, and AID11 are set, so that the MLD access point device is buffering frames addressed to MLD station devices corresponding to AID4, AID8, AID9, and AID11.

[0140] The Multi-Link Traffic Indication Element in this embodiment is a variant based on the AID Bitmap Element. The Multi-Link Traffic Indication Element is composed of a Bitmap Size field, a Link Bitmap Pattern field, and a Partial AID Bitmap field. The Bitmap Size field in this embodiment may specify the size of the Link Bitmap Pattern field. The Multi-Link Traffic Indication Element may not include any of the above fields, or may include an AID Bitmap Offset and a Link ID Offset as separate fields.

[0141] Here, the size of the Link Bitmap Pattern field is set to "4", and in this case, the Link Bitmap Pattern is expressed as links 1 through 4. If the use of links 2 and 3 is specified (or recommended) for the MLD station equipment corresponding to AID4, the Link Bitmap Pattern is expressed as "0", "1", "1", "0". If the use of links 2 and 4 is specified (or recommended) for the MLD station equipment corresponding to AID8, the Link Bitmap Pattern is expressed as "0", "1", "0", "1". If the use of links 2 and 4 is specified (or recommended) for the MLD station equipment corresponding to AID9, the Link Bitmap Pattern is expressed as "0", "1", "0", "1", which is the same as the Link Bitmap Pattern for AID8 described above. If the use of links 3 and 4 is specified (or recommended) for the MLD station equipment corresponding to AID11, the Link Bitmap Pattern is expressed as "0", "0", "1", "1".

[0142] Frame 16-12 is a Multi-Link Traffic Indication Element that specifies the Link Bitmap Pattern as "0", "1", "1", and "0". In this example, only AID4 uses this Link Bitmap Pattern, so in the Partial AID Bitmap, only the bit corresponding to AID4 is set.

[0143] Frame 16-13 is a Multi-Link Traffic Indication Element that specifies the Link Bitmap Pattern as "0", "1", "0", and "1". In this example, AID8 and AID9 use this Link Bitmap Pattern, so the bits in the Partial AID Bitmap that correspond to AID8 and AID9 are set.

[0144] Frame 16-14 is a Multi-Link Traffic Indication Element that specifies the Link Bitmap Pattern as "0", "0", "1", and "1". In this example, only AID11 uses this Link Bitmap Pattern, so in the Partial AID Bitmap, only the bit corresponding to AID11 is set.

[0145] In this way, by using a combination of the Link Bitmap Pattern and the Partial AID Bitmap, each MLD station device corresponding to each AID can notify which link it is designated (or recommended) to use.

[0146] As mentioned above, the Multi-Link Traffic Indication Element may include the AID Bitmap Offset. In the case of 16-14, since the first byte of the Partial AID Bitmap is all 0, the first byte of the Partial AID Bitmap may be removed from the Multi-Link Traffic Indication element by setting the AID Bitmap Offset to "1".

[0147] As mentioned above, the Multi-Link Traffic Indication Element may include a Link ID Offset. In the example of FIG. 16, since the use of Link 1 is not specified (or recommended) for Frame 16-12, the Link Bitmap Pattern may be expressed for Links 2 to 4 by specifying "1" for the Link ID Offset and "3" for the Bitmap Size field. In this case, the Link Bitmap Pattern for AID4 may be expressed as "1", "1", "0", and the Link Bitmap Patterns for AID8 and AID9 may be expressed as "1", "0", "1". Since the use of Links 1 and 2 is not specified (or recommended) for Frame 16-14, the Link Bitmap Pattern may be expressed for Links 3 to 4 by specifying "2" for the Link ID Offset and "2" for the Bitmap Size field. In this case, the Link Bitmap Pattern for AID11 may be expressed as "1", "1".

[0148] In this way, AIDs having the same Link Bitmap Pattern are collected and described in one Multi-Link Traffic Indication Element, and multiple Multi-Link Traffic Indication Elements with different Link Bitmap Patterns are used to notify each MLD station device of which links it is designated (or recommended) to use. Also, a combination of multiple Multi-Link Traffic Indication Elements may be used to notify each MLD station device of all links it is designated (or recommended) to use.

[0149] [4. Fourth embodiment] In the fourth embodiment, a method of notifying each MLD station device of which link it is specified (or recommended) to use, using a link number instead of the Link Bitmap pattern described in the third embodiment, will be described with reference to Fig. 17. As in the third embodiment, in this embodiment, the MLD access point device does not transmit an AID Bitmap Element to the MLD station device, but transmits only a Multi-Link Traffic Indication Element, thereby notifying each MLD station device of the link it will use. To supplement this, information equivalent to a Partial AID Bitmap (equivalent to a Partial Virtual Bitmap) included in the AID Bitmap Element is placed in the Multi-Link Traffic Indication Element.

[0150] In this case, one Multi-Link Traffic Indication Element allows each MLD station device to notify only one of the links that it is designated (or recommended) to use, and a combination of multiple Multi-Link Traffic Indication Elements enables each MLD station device to notify all of the links that it is designated (or recommended) to use.

[0151] In this example, the value of the Bitmap Offset of the AID Bitmap Element is 0, and 16 bits are allocated to the Partial AID Bitmap, so that AID1 to AID16 can be expressed. Each bit in the Partial AID Bitmap field indicates, in order from the left, whether or not frames addressed to station devices corresponding to AID1 to AID16 are buffered. In this example, the bits corresponding to AID4, AID8, AID9, and AID11 are set, so that the MLD access point device is buffering frames addressed to MLD station devices corresponding to AID4, AID8, AID9, and AID11.

[0152] In this embodiment, the Multi-Link Traffic Indication is composed of a Bitmap Size field, a Link ID field, and a Partial AID Bitmap. The Multi-Link Traffic Indication Element may not include any of the above fields, or may include an AID Bitmap Offset and a Link ID Offset as separate fields.

[0153] In frame 17-12, the Link ID field is a Multi-Link Traffic Indication Element that specifies link 2. In this example, AID4, AID8, and AID9 are specified (or recommended) for use on link 2, so in the Partial AID Bitmap, only the bits corresponding to AID4, AID8, and AID9 are set.

[0154] In frame 17-13, the Link ID field is a Multi-Link Traffic Indication Element that specifies link 3. In this example, AID4 and AID11 are specified (or recommended) for use with link 3, so in the Partial AID Bitmap, only the bits corresponding to AID4 and AID11 are set.

[0155] In frame 17-14, the Link ID field is a Multi-Link Traffic Indication Element that specifies link 4. In this example, AID9 and AID11 are specified (or recommended) for use with link 4, so in the Partial AID Bitmap, only the bits corresponding to AID9 and AID11 are set.

[0156] In this way, the Link ID field allows each MLD station device corresponding to each AID to notify which link it is designated (or recommended) to use.

[0157] As mentioned above, the Multi-Link Traffic Indication element may include an AID Bitmap Offset. In 17-14, since the first byte of the Partial AID Bitmap is all 0, the first byte of the Partial AID Bitmap may be removed from the Multi-Link Traffic Indication Element by setting the AID Bitmap Offset to "1."

[0158] In this way, AIDs having the same link number can be grouped together and written in one Multi-Link Traffic Indication Element, and multiple Multi-Link Traffic Indication Elements with different link numbers can be used to notify each MLD station device of which link it is designated (or recommended) to use. [5. Common to all embodiments]

[0159] The communication device according to the present invention can communicate in a frequency band (frequency spectrum) called an unlicensed band, which does not require permission to use from a country or region, but the available frequency band is not limited to this. The communication device according to the present invention can also be effective in a frequency band called a white band (for example, a frequency band allocated for television broadcasting but unused in some regions) that is not actually used for the purpose of preventing interference between frequencies even though permission to use the band for a specific service is given by a country or region, and in a shared spectrum (shared frequency band) that is expected to be shared by multiple operators.

[0160] The program that operates in the wireless communication device according to the present invention is a program that controls the CPU, etc. (a program that makes a computer function) so as to realize the functions of the above-mentioned embodiments of the present invention. Information handled by these devices is temporarily stored in the RAM during processing, and then stored in various ROMs or HDDs, and is read, modified, and written by the CPU as necessary. The recording medium that stores the program may be any of semiconductor media (e.g., ROM, non-volatile memory card, etc.), optical recording media (e.g., DVD, MO, MD, CD, BD, etc.), magnetic recording media (e.g., magnetic tape, flexible disk, etc.), etc. In addition, not only the functions of the above-mentioned embodiments are realized by executing the loaded program, but also the functions of the present invention may be realized by processing in cooperation with an operating system or other application programs, etc. based on instructions from the program.

[0161] In addition, when distributing the program on the market, the program can be stored in a portable recording medium and distributed, or transferred to a server computer connected via a network such as the Internet. In this case, the storage device of the server computer is also included in the present invention. In addition, a part or all of the communication device in the above-mentioned embodiment may be realized as an LSI, which is typically an integrated circuit. Each functional block of the communication device may be individually formed into a chip, or a part or all of the functional blocks may be integrated into a chip. When each functional block is formed into an integrated circuit, an integrated circuit control unit that controls them is added.

[0162] In addition, the method of integration is not limited to LSI, but may be a dedicated circuit or a general-purpose processor. In addition, if an integrated circuit technology that can replace LSI appears due to the advancement of semiconductor technology, it is also possible to use an integrated circuit based on that technology.

[0163] The present invention is not limited to the above-mentioned embodiment. The wireless communication device of the present invention is not limited to application to a mobile station device, but can be applied to stationary or non-movable electronic devices installed indoors or outdoors, such as AV equipment, kitchen equipment, cleaning and washing machines, air conditioners, office equipment, vending machines, and other household appliances.

[0164] Although an embodiment of the present invention has been described in detail above with reference to the drawings, the specific configuration is not limited to this embodiment, and designs and the like that do not deviate from the gist of the present invention are also included in the scope of the claims. [Industrial Applicability]

[0165] The present invention is suitable for use in a communication device and a communication method. [Explanation of symbols]

[0166] 1-1, 1-2 (MLD) access point device 2-1~2-6 (MLD) Station Equipment 3-1, 3-2 Wireless communication system 10000-1 Wireless communication device 10001-1 Upper layer processing unit 10001a-1 Multi-link control unit 10002-1 Control section 10002a-1 CCA Department 10002b-1 Backoff section 10002c-1 Transmission decision unit 10003-1 Transmitter 10003a-1 Physical layer frame generator 10003b-1 Radio transmitter 10004-1 Receiver 10004a-1 Radio receiver 10004b-1 Signal demodulation section 10004c-1 Reception quality measurement unit 10005-1 Antenna section 20000-1 MLD access point device 20000-2, 20000-3, 20000-4 Sub wireless communication devices (sub access point devices) 30000-1 MLD station equipment 30000-2, 30000-3, 30000-4 Sub-wireless communication equipment (substation equipment) 10-1 Multi-link establishment request 10-2 Multilink establishment response 10-4, 10-5, 10-6 Management Frame 10-7 Control Frame 10-8 Frame 12-11, 12-12, 13-11, 13-12, 14-11, 14-12, 14-21, 14-22, 15-11, 15-12, 16-11, 16-12, 16-13, 16-14, 17-11, 17-12, 17-13, 17-14 Frame configuration 14-1, 14-2 frame combination

Claims

1. An access point device that communicates with a plurality of station devices, communicating with the plurality of station devices using a plurality of links; a transmitting unit and a receiving unit corresponding to each of the plurality of links; transmitting a frame including multilink traffic indication information to the plurality of station devices by any one of the transmitting units; the multilink traffic indication information includes one or more first pieces of information; The first information is The traffic display bitmap information is identified by any combination of traffic display bitmap information, information specifying a size to be allocated to the traffic display bitmap information, and link information for the traffic display bitmap information.

1. An access point device comprising:

2. The link information indicates whether millimeter waves are included in the target of the traffic display bitmap information.

2. The access point device according to claim 1.

3. The frame includes the multilink traffic indication information for links including millimeter wave in addition to the multilink traffic indication information for microwave.

2. The access point device according to claim 1.

4. A station device that communicates with an access point device, communicating with the access point device using a plurality of links; a transmitting unit and a receiving unit corresponding to each of the plurality of links; receiving a frame including multilink traffic indication information from the access point device by any one of the receiving units; the multilink traffic indication information includes one or more first pieces of information; The first information is The traffic indicator bitmap information is configured by any combination of: traffic indicator bitmap information; information specifying a size to be allocated to the traffic indicator bitmap information; and link information for the traffic indicator bitmap information. A station device characterized by:

5. The link information indicates whether millimeter waves are included in the target of the traffic display bitmap information.

5. The station device according to claim 4.

6. The frame includes the multilink traffic indication information for links including millimeter wave in addition to the multilink traffic indication information for microwave.

5. The station device according to claim 4.

7. A communication method implemented by an access point device, comprising: communicating with a plurality of station devices using a plurality of links; transmitting a frame including multilink traffic indication information to the plurality of station devices; the multilink traffic indication information includes one or more first pieces of information; The first information is The traffic indicator bitmap information is configured by any combination of: traffic indicator bitmap information; information specifying a size to be allocated to the traffic indicator bitmap information; and link information for the traffic indicator bitmap information. A communication method comprising:

8. The link information indicates whether millimeter waves are included in the target of the traffic display bitmap information.

8. The communication method according to claim 7.

9. The frame includes the multilink traffic indication information for a link including millimeter wave in addition to the multilink traffic indication information for microwave.

8. The communication method according to claim 7.

Images