Wireless communication device, wireless communication method, wireless communication terminal, and wireless communication method

Abstract

The present technology pertains to a wireless communication device, a wireless communication method, a wireless communication terminal, and a wireless communication method, whereby communication efficiency can be improved. A wireless communication device of the present technology comprises a communication control unit that determines a link for frame transmission to a wireless communication terminal from among a plurality of links on the basis of information on a first transition time for each of the plurality of links, the first transition time is necessary for the wireless communication terminal to transition from a multi-link state in which communication is performed by using the plurality of links to a single-link state in which communication can be performed by using any one of the links. The present technology can be applied, for example, to a wireless communication device compatible with EMLSR operation.

Description

Technical Field

[0001] The present technology relates to a wireless communication device and a wireless communication method, and a wireless communication terminal and a wireless communication method, and more particularly, to a wireless communication device and a wireless communication method, and a wireless communication terminal and a wireless communication method capable of improving communication efficiency. Background Art

[0002] Wireless communication using multiple links (multi-link operation (MLO)) has been studied as a method of coping with high transmission speed requirements such as 8K transmission or xReality (xR). A "link" is a wireless transmission path through which data can be transmitted between two wireless communication devices.

[0003] When MLO is performed, each link is selected from a plurality of mutually independent wireless transmission paths divided in the frequency domain, for example.

[0004] A device compatible with MLO is called a multi-link device (MLD). MLD is a logical entity including two or more stations (STAs) and has only one service access point (SAP) to a higher layer. An MLD in which each included STA functions as an access point (AP) is called an AP MLD, and an MLD in which each included STA functions as a non-AP STA is called a non-AP MLD. Each entity in the MLD may be expressed, for example, as an AP belonging to an AP MLD (AP MLD-affiliated AP) or a non-AP STA belonging to a non-AP MLD (non-AP MLD-affiliated non-AP STA) to specify that it is an entity inside the MLD.

[0005] As one of the MLOs, an enhanced multi-link single radio (EMLSR) operation or an enhanced multi-link multi-radio (EMLMR) operation capable of performing communication by using a plurality of links and transmitting and receiving a plurality of streams using one link is standardized.

[0006] Citation List

[0007] Non-patent literature

[0008] Non-patent document 1: Minyoung Park et al., “CC34 CR EMLSR part2”, IEEE 802.11-21 / 0287r9, December 20, 2021 Summary of the invention

[0009] Problems to be solved by the present invention

[0010] During the EMLSR operation and the EMLMR operation, the non-AP MLD transitions from a multi-link state in which communication is performed by using multiple links to a single-link state in which multiple flows are transmitted and received by using one link. If the AP MLD transmits a frame to the non-AP MLD before the state transition is completed in the non-AP MLD, the non-AP MLD may not receive the frame.

[0011] Therefore, as disclosed in Non-Patent Document 1, the non-AP MLD notifies the AP MLD of EMLSR filling delay and EMLSR transition delay, and the AP MLD needs to wait to send a frame to the non-AP MLD during a period in which the non-AP MLD transitions from a multi-link state to a single-link state.

[0012] The transition time required for the non-AP MLD to transition from the multi-link state to the single-link state varies depending on, for example, the operating frequency of the non-AP MLD. In the notification method disclosed in Non-Patent Document 1, since only the maximum value of the transition time required for the non-AP MLD to transition the state is notified to the AP MLD, even if the state transition is completed in the non-AP MLD, the AP MLD waits to send a frame, and thus the communication efficiency during the EMLSR operation may be reduced.

[0013] The present technology has been proposed in view of such circumstances, and its purpose is to improve communication efficiency. Solution to the problem

[0014] A wireless communication device of a first aspect of the present technology includes a communication control unit that determines a link for frame transmission to a wireless communication terminal from among a plurality of links based on information about a first transition time for each of the plurality of links, the first transition time being required for the wireless communication terminal to transition from a multi-link state in which communication is performed by using a plurality of links to a single-link state in which communication can be performed by using any one of the links.

[0015] A wireless communication method according to a first aspect of the present technology is performed by a wireless communication device, comprising: determining a link for transmitting a frame to a wireless communication terminal from among a plurality of links based on information about a first transition time of each of a plurality of links, the first transition time being a transition time required for the wireless communication terminal to transition from a multi-link state in which communication is performed by using a plurality of links to a single-link state in which communication can be performed by using any one of the links.

[0016] A wireless communication terminal according to a second aspect of the present technology includes a communication control unit that communicates with a wireless communication device, wherein the communication control unit sends information about a first transition time for each of a plurality of links to the wireless communication device, the first transition time being required for the wireless communication terminal to transition from a multi-link state in which communication is performed by using a plurality of links to a single-link state in which communication can be performed by using any one of the links.

[0017] The wireless communication method of the second aspect of the present technology is performed by a wireless communication terminal communicating with a wireless communication device, including: sending information about a first transition time for each of a plurality of links to the wireless communication device, the first transition time being required for the wireless communication terminal to transition from a multi-link state in which communication is performed by using a plurality of links to a single-link state in which communication can be performed by using any one of the links.

[0018] In a first aspect of the present technology, a link for transmitting a frame to a wireless communication terminal is determined based on information about a first transition time for each of a plurality of links, the first transition time being required for the wireless communication terminal to transition from a multi-link state in which communication is performed by using a plurality of links to a single-link state in which communication can be performed by using any one of the links.

[0019] In a second aspect of the present technology, information about a first transition time required for a wireless communication terminal to transition from a multi-link state in which channel scanning of multiple links is performed to a single-link state in which communication can be performed by using each of the multiple links is sent to a wireless communication device by a communication control unit that communicates with the wireless communication device using multiple links. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 is a diagram illustrating a configuration example of a wireless communication system to which the present technology can be applied.

[0021] Figure 2 is a diagram schematically illustrating a configuration example of a non-AP MLD.

[0022] Figure 3 It is a sequence diagram of EMLSR operation.

[0023] Figure 4 3 is a diagram illustrating a single-link transmission / reception state of link 3.

[0024] Figure 5 is a diagram illustrating a multi-link scanning state.

[0025] Figure 6 1 is a diagram illustrating a single link transmission / reception state of Link 1.

[0026] Figure 7is a diagram schematically illustrating another configuration example of a non-AP MLD.

[0027] Figure 8 It is a sequence diagram of EMLMR operation.

[0028] Fig. 9 is a diagram illustrating a multi-link operation state.

[0029] Fig.10 is a diagram illustrating a single-link operation state of link 1.

[0030] Fig.11 is a block diagram illustrating a functional configuration example of an AP MLD.

[0031] Fig.12 is a block diagram illustrating a functional configuration example of a non-AP MLD compatible with the EMLSR operation.

[0032] Fig.13 is a block diagram illustrating a functional configuration example of a non-AP MLD compatible with the EMLMR operation.

[0033] Fig.14 : is a flowchart for describing the flow of an operation in which the non-AP MLD notifies the APMLD of information on the transition time of the state in the own terminal.

[0034] Fig.15 is a diagram illustrating an example of a configuration example of a multilink element.

[0035] Fig.16 is a flowchart for describing the flow of operation of the AP MLD determining a link for frame transmission.

[0036] Fig.17 It is a sequence diagram of the EMLSR operation performed by the wireless communication system of the present technology.

[0037] Fig.18 It is a sequence diagram of EMLMR operation performed by the wireless communication system of the present technology. DETAILED DESCRIPTION

[0038] Hereinafter, a mode for carrying out the present technology will be described. The description will be made in the following order.

[0039] 1. System Configuration

[0040] 2. Configuration and operation of each device

[0041] 3. First Embodiment (Example of EMLSR Operation)

[0042] 4. Second Embodiment (Example of EMLMR Operation)

[0043] <1. System Configuration>

[0044] - Configuration example of wireless communication system

[0045] Figure 1 is a diagram illustrating a configuration example of a wireless communication system to which the present technology can be applied.

[0046] exist Figure 1 In a wireless communication system, multiple links (MLO) are used to send and receive data through wireless communication.

[0047] When performing MLO, for example, each link is selected from a plurality of mutually independent wireless transmission paths divided in the frequency domain. For example, each channel selected from a plurality of channels included in any one of the frequency bands such as the 2.4 GHz band, the 5 GHz band, the 6 GHz band, and the 920 MHz band is used as each link.

[0048] A device compatible with MLO is referred to as an MLD as described above. An MLD is a logical entity including two or more STAs, and has only one SAP for a higher layer. An MLD in which each of the included STAs functions as an AP is referred to as an AP MLD, and an MLD in which each of the included STAs functions as a non-AP STA is referred to as a non-AP MLD. Each entity in an MLD may be expressed, for example, as an AP belonging to an AP MLD or a non-AP STA belonging to a non-AP MLD to specify that it is an entity inside an MLD.

[0049] Figure 1 The wireless communication system in FIG. 1 includes one AP MLD 1 and two non-AP MLDs, namely, non-AP MLD 2-1 and non-AP MLD 2-2. Non-AP MLDs 2-1 and 2-2 are connected to AP MLD 1.

[0050] exist Figure 1 , a solid line connecting AP MLD 1 with non-AP MLDs 2-1 and 2-2 indicates link 1, and a dotted line connecting AP MLD 1 with non-AP MLDs 2-1 and 2-2 indicates link 2. A long and short alternating dotted line connecting AP MLD 1 with non-AP MLDs 2-1 and 2-2 indicates link 3. As link 1 to link 3, three channels may be selected from one frequency band, or three channels may be selected from different frequency bands. In addition, the number of links used between AP MLD and non-AP MLD is not limited to three. For example, two links may be used, or four or more links may be used.

[0051] The AP MLD 1 is a wireless communication device that operates as a base station compatible with MLO. The AP MLD 1 communicates with the non-AP MLDs 2-1 and 2-2 by using Link 1 to Link 3.

[0052] The non-AP MLDs 2-1 and 2-2 are wireless communication terminals that operate as terminals compatible with MLO.

[0053] Note that the number of non-AP MLDs connected to AP MLD 1 is not limited to two and may be any number. Hereinafter, in the case where non-AP MLD 2-1 and 2-2 do not need to be distinguished from each other, each of non-AP MLD 2-1 and 2-2 is simply referred to as non-AP MLD 2.

[0054] -EMLSR Operation

[0055] Figure 2 is a diagram schematically illustrating a configuration example of the non-AP MLD 2.

[0056] like Figure 2 As shown in FIG, the non-AP MLD 2 includes 3 antennas, 3 RF units, 2 simple PHY units (small PHY units), 1 PHY unit, 3 lower MAC units and 1 upper MAC unit.

[0057] The three sets of antennas and RF units are each operable for the same frequency band.

[0058] The PHY unit is a signal processing unit compatible with, for example, IEEE802.11be. The simple PHY unit may perform similar processing to the PHY unit, but is a signal processing unit with limited functionality compared to the PHY unit. The simple PHY unit is compatible with channel scanning and reception processing such as a multi-user request to send (MU-RTS) frame or a buffer status report polling (BSRP) trigger frame.

[0059] As a configuration of a non-AP MLD compatible with MLO, it is assumed that a plurality of PHY units compatible with IEEE802.11be are installed, but there is a case where the same number of PHY units as the number of links used for communication cannot be installed due to limitations on terminal size, etc. In order to perform MLO even in such a case, some of the plurality of PHY units installed on the non-AP MLD 2 are replaced with simple PHY units having only simple functions such as channel scanning.

[0060] The three lower MAC units perform processing for the corresponding links so that the non-AP MLD 2 can operate by using a maximum of three links. The upper MAC unit performs processing common to the MLD.

[0061] In the non-AP MLD 2, the RF unit and the PHY unit or the simple PHY unit, and the PHY unit or the simple PHY unit and the lower MAC unit are each connected through a switch SW, and a functional block to be used is changed according to the situation.

[0062] With the above-described configuration, the non-AP MLD 2 can perform an EMLSR operation capable of performing communication by using a plurality of links and transmitting and receiving a plurality of spatially multiplexed streams by using any one of the plurality of links.

[0063] Figure 3 It is a sequence diagram of EMLSR operation.

[0064] Here, a case where AP1 belonging to AP MLD 1 acquires the transmission right prior to AP2 and AP3 will be described, but a similar sequence also applies to a case where AP2 and AP3 belonging to AP MLD 1 acquire the transmission right prior to other entities.

[0065] First, when connecting with the AP MLD 1, the non-AP MLD 2 exchanges parameters and the like necessary for performing communication with the links 1 to 3 by using, for example, an EML operation mode notification (EMLOMN) frame. When exchanging the EML OMN frame, the non-AP MLD 2 operates each RF unit at (the frequency of) the link 3 and switches the switch SW so that the lower MAC unit corresponding to the link 3 and the PHY unit and the PHY unit and each RF unit are connected, as shown in FIG. Figure 4 Note that the operation of the simple PHY unit is turned off.

[0066] Therefore, the non-AP MLD 2 can transmit and receive a plurality of spatially multiplexed streams by using only the link 3. Here, the link 3 is an enabled link, and the link 1 and the link 2 are disabled links.

[0067] Return to Figure 3 , non-AP MLD 2 sends an EML OMN frame to AP MLD 1 by using link 3, in which the EMLSR mode subfield is set to 1 and it is written that the desire to perform EMLSR operation at link 1 to link 3 is desired.

[0068] Note that, hereinafter, an example will be described in which the non-AP MLD 2 designates Link 1 to Link 3 as links to be scanned during the EMLSR operation (EMLSR links), but, for example, only Link 1 and Link 2 may be designated as EMLSR links. By designating only Link 1 and Link 2 as EMLSR links, the non-AP MLD 2 can turn off the operation of the PHY unit when performing channel scanning to reduce power consumption, and turn on the operation of the PHY unit only when performing communication by using one link.

[0069] In case that the AP MLD 1 which receives the EML OMN frame by using the link 3 allows the EMLSR operation, the AP MLD 1 transmits the EML OMN frame with the EMLSR Mode subfield set to 1 to the non-AP MLD 2 by using the link 3 .

[0070] After the exchange of the EML OMN frame is completed, the non-AP MLD 2 starts the simple PHY unit and switches the operating frequency of the RF unit operating at the link 3 to the link 1 and the link 2, as shown in FIG. Figure 5 , so as to perform EMLSR operation. In addition, the non-AP MLD 2 switches the switch SW so that the RF unit operating at link 1 is connected to the simple PHY unit and the simple PHY unit corresponding to link 1 (and connected to the RF unit operating at link 1) is connected to the lower MAC unit corresponding to link 1, and the RF unit operating at link 2 is connected to the simple PHY unit and the simple PHY unit corresponding to link 2 and the lower MAC unit corresponding to link 2.

[0071] Therefore, non-AP MLD 2 can perform channel scanning at Link 1 to Link 3 and receive MU-RTS frames or BSRP trigger frames. Figure 5 The state of the non-AP MLD 2 shown in FIG. 1 is called the multi-link scanning state. By transitioning to the multi-link scanning state, the non-AP MLD 2 starts the EMLSR mode.

[0072] Back to Figure 3 After the exchange of the EML OMN frame is completed, the AP MLD 1 sends a PHY protocol data unit (PPDU) to the non-AP MLD 2 in the EMLSR mode by using the link 1. Figure 3 In the example of FIG. 4 , the MU-RTS frame (or BSRP trigger frame) is sent as a PPDU.

[0073] In order to transmit and receive frames by using link 1, non-APMLD 2, which has received the MU-RTS frame by using link 1, operates each RF unit on link 1 and switches switch SW so that the lower MAC unit corresponding to link 1 and the PHY unit and the PHY unit and each RF unit are connected, as shown in FIG. Figure 6 Note that the operation of the simple PHY unit is turned off.

[0074] Therefore, the non-AP MLD 2 may transmit a clear-to-send (CTS) frame or a buffer status report (BSR) frame as a response to the MU-RTS frame or the BSRP trigger frame by using the link 1. In addition, after transmitting the CTS frame or the BSR frame, the non-AP MLD 2 may receive one stream or multiple spatially multiplexed streams transmitted from the AP MLD 1, and may transmit one stream or multiple spatially multiplexed streams to the AP MLD 1. In the following, Figure 6 The state of the non-AP MLD 2 shown in FIG. 2 is called a single-link transmission / reception state.

[0075] Return to Figure 3 , after completing the transition to the single link transmission / reception state, the non-AP MLD 2 transmits a CTS frame (or a BSR frame) to the AP MLD 1 by using the link 1. Note that padding is added to the MU-RTS frame transmitted by the AP MLD 1 so that the non-AP MLD 2 can transmit the CTS frame after completing the transition to the single link transmission / reception state.

[0076] The AP MLD 1 receiving the CTS frame by using the link 1 transmits a data frame of Data 1 to the non-AP MLD 1 by using the link 1. The data frame of Data 1 is transmitted by using, for example, one stream or a plurality of spatially multiplexed streams.

[0077] The non-AP MLD 2 which has received the data frame of the data 1 by using the link 1 transmits an ACK frame to the AP MLD 1 by using the link 1 .

[0078] When transmission and reception of data frames with the AP MLD 2 are finished, the non-AP MLD 2 transitions to the multi-link scanning state to perform channel scanning for each link. Note that, during the transition of the non-AP MLD 2 from the single-link transmission / reception state to the multi-link scanning state, the AP MLD 1 waits without transmitting a MU-RTS frame.

[0079] -EMLMR Operation

[0080] Figure 7 is a diagram schematically illustrating another configuration example of the non-AP MLD 2.

[0081] Figure 7 The configuration of non-AP MLD 2 in Figure 2 The configuration in is different because two PHY units are provided instead of two simple PHY units.

[0082] exist Figure 7In the non-AP MLD 2, the RF unit and the PHY unit, and the PHY unit and the lower MAC unit are each connected through a switch SW, and the functional blocks to be used are changed according to the situation.

[0083] Even in a configuration including a plurality of PHY units without the above-described simple PHY unit, the non-AP MLD 2 can perform an EMLMR operation capable of dynamically changing the number of flows transmitted and received by using each link.

[0084] Figure 8 It is a sequence diagram of EMLMR operation.

[0085] Here, a case where AP1 belonging to AP MLD 1 acquires the transmission right prior to AP2 and AP3 will be described, but a similar sequence also applies to a case where AP2 and AP3 belonging to AP MLD 1 acquire the transmission right prior to other entities.

[0086] First, when exchanging EML OMN frames, non-AP MLD 2 operates three RF units at corresponding links among Link 1 to Link 3, such as Fig. 9 In addition, the non-AP MLD 2 switches the switch SW so that the RF unit and the PHY unit operating at link 1 and the PHY unit corresponding to link 1 and the lower MAC unit corresponding to link 1 are connected, the RF unit and the PHY unit operating at link 2 and the PHY unit corresponding to link 2 and the lower MAC unit corresponding to link 2 are connected, and the RF unit and the PHY unit operating at link 3 and the PHY unit corresponding to link 3 and the lower MAC unit corresponding to link 3 are connected.

[0087] Since the same number of PHY units as the number of links used for communication are provided, the non-AP MLD 2 can be used in Fig. 9 In the state shown in , data frames are sent and received through one flow by using each link. In the following, Fig. 9 The state of non-AP MLD 2 shown in FIG. 2 is called a multi-link operation state.

[0088] Return to Figure 8 , non-AP MLD 2 sends an EML OMN frame to AP MLD 1, for example, by using link 3, in which the EMLMR mode subfield is set to 1 and writes that it is desired to perform an EMLMR operation at link 1 to link 3.

[0089] In case that the AP MLD 1 which receives the EML OMN frame by using the link 3 allows the EMLMR operation, the AP MLD 1 transmits the EML OMN frame whose EMLMR Mode subfield is set to 1 to the non-AP MLD 2 by using the link 3 .

[0090] After the exchange of the EML OMN frames is completed, the non-AP MLD 2 starts the EMLMR mode, and the AP MLD 1 sends the PPDU to the non-AP MLD 2 in the EMLMR mode by using the link 1. After the EML OMN frames are exchanged, in the EMLSR operation, the MU-RTS frame and the BSRP trigger frame are sent by the AP MLD 1, but in the EMLMR operation, the data frame can be sent as a PPDU. Figure 8 In the example shown in FIG. 1 , a data frame of data 0 is transmitted as a PPDU.

[0091] The non-AP MLD2 that receives the data frame of data 0 at link 1 operates each RF unit at link 1 and switches the switch SW so that the lower MAC unit corresponding to link 1 is connected to a PHY unit and the PHY unit is connected to each RF unit, such as Fig.10 as shown in .

[0092] Therefore, the non-AP MLD 2 can transmit and receive multiple spatially multiplexed streams by using the link 1. In the following, Fig.10 The state of non-AP MLD 2 shown in FIG. 2 is called a single-link operation state.

[0093] Note that in order to reduce power consumption, the operation of the PHY unit not connected to the RF unit may be shut down in the single-link operation state, and when the non-AP MLD 2 transitions to the multi-link operation state again, the PHY unit not connected to the RF unit may be started.

[0094] Return to Figure 8 , after completing the transition to the single link operation state, non-AP MLD 2 sends an ACK frame to AP MLD 1 by using link 1. Note that padding is also added to the data frame of data 0 sent by AP MLD 1 so that non-AP MLD 2 can send an ACK frame after completing the transition to the single link transmission / reception state.

[0095] The AP MLD 1 receiving the ACK frame by using the link 1 transmits a data frame of data 1 to the non-AP MLD 1 by using the link 1. The data frame of data 1 is transmitted by using, for example, one stream or a plurality of spatially multiplexed streams.

[0096] The non-AP MLD 2 which has received the data frame of the data 1 by using the link 1 transmits an ACK frame to the AP MLD 1 by using the link 1 .

[0097] When data transmission and reception with AP MLD 2 ends, non-AP MLD 2 transitions to the multi-link operation state to perform channel scanning of each link. Note that during the period when non-AP MLD 2 transitions from the single-link operation state to the multi-link operation state, AP MLD 1 waits without transmitting PPDU.

[0098] -question

[0099] During the EMLSR operation or the EMLMR operation, as described above, the non-AP MLD 2 transitions from the multi-link state (multi-link scanning state or multi-link operation state) in which communication is performed by using a plurality of links to the single-link state (single-link transmission / reception state or single-link operation state) in which a plurality of streams are transmitted and received by using any one of the plurality of links. If the AP MLD transmits a frame to the non-AP MLD before the state transition is completed in the non-AP MLD 2, the non-AP MLD may not receive the frame.

[0100] Therefore, as disclosed in Non-Patent Document 1, non-AP MLD2 notifies AP MLD1 of EMLSR filling delay and EMLSR transition delay, and AP MLD1 needs to wait to send a frame to non-AP MLD2 in a period in which non-AP MLD2 transitions from a multi-link state to a single-link state.

[0101] In addition, the transition time required for the non-AP MLD 2 transition state is determined based on the switching time of the operating frequency of the RF unit, the switching time of the connection destination of each of the RF unit, the PHY unit, the simple PHY unit and the lower MAC unit, and the time required to turn on / off the PHY unit and the simple PHY unit.

[0102] The switching time of the operating frequency of the RF unit is different depending on the operating frequency before the switching and the operating frequency after the switching. The time required to turn on / off the simple PHY unit and the PHY unit is different depending on the number of the simple PHY unit and the PHY unit started in the multi-link state. Therefore, the transition time required for the non-AP MLD 2 to transition from the multi-link state to the single-link state is different depending on the operating frequency of the non-AP MLD 2, etc.

[0103] In the notification method disclosed in non-patent document 1, since only the maximum value of the transition time required for the transition state is notified to AP MLD 1, AP MLD 1 waits to send a frame even if the state transition is completed in non-AP MLD 2, so the communication efficiency during EMLSR operation may decrease.

[0104] Therefore, in the present technology, information about the transition time of each link required for non-AP MLD 2 to transition from the multi-link state to the single-link state is notified to AP MLD 1, and a link for frame transmission during EMLSR operation is determined based on the information, thereby improving communication efficiency.

[0105] <2. Configuration and operation of each device>

[0106] -AP MLD 1 configuration

[0107] Fig.11 is a block diagram illustrating a functional configuration example of the AP MLD 1.

[0108] like Fig.11 As shown in , the AP MLD 1 includes a wireless communication unit 110 , a control unit 120 , a storage unit 130 , and an antenna 140 .

[0109] The wireless communication unit 110 includes a communication control unit 151 , a communication storage unit 152 , a common data processing unit 153 , an individual data processing unit 154 , a signal processing unit 155 , a wireless interface unit 156 , and an amplification unit 157 .

[0110] The wireless communication unit 110 has functional blocks after the individual data processing unit 154 for each link, and for example, the functional blocks on the left side of the figure operate as AP 1, the functional blocks in the center of the figure operate as AP 2, and the functional blocks on the right side of the figure operate as AP 3. A group including the wireless interface unit 156, the amplification unit 157, and the antenna 140 can operate as one AP belonging to AP MLD1.

[0111] The communication control unit 151 controls the operation of each unit of the wireless communication unit 110 and the information transmission between the units. In addition, the communication control unit 151 controls the transmission of control information and management information to be notified to other communication devices to each processing unit. In particular, in the present technology, the communication control unit 151 receives information on the transition time of each link transmitted from the non-AP MLD 2, and controls each processing unit to determine a link for frame transmission based on the information.

[0112] The communication storage unit 152 holds various types of information used by the communication control unit 151 .

[0113] At the time of data transmission, the common data processing unit 153 performs sequence management on the data held in the communication storage unit 152 and the control information and management information received from the communication control unit 151, and performs encryption processing, etc. Thereafter, the common data processing unit 153 transmits the temporary data unit to the individual data processing unit 154 of any AP among AP 1 to AP 3 that has acquired the transmission right. At the time of data reception, the common data processing unit 153 performs decryption processing and reordering processing on the temporary data unit received from the individual data processing unit 154. The common data processing unit 153 is also referred to as an upper MAC unit.

[0114] When data is transmitted, the individual data processing unit 154 performs a channel access operation based on carrier sensing. In addition, when data is transmitted, the individual data processing unit 154 adds a medium access control (MAC) header and an error detection code to a temporary data unit received from the common data processing unit 153, and performs coupling processing of multiple data units. When data is received, the individual data processing unit 154 performs decoupling of the received data unit, analysis and error detection of the MAC header, and transmits the data unit to the common data processing unit 153. In addition, when data is received, the individual data processing unit 154 performs a retransmission request operation. The individual data processing unit 154 is also called a lower MAC unit.

[0115] Note that the function of the individual data processing unit 154 that performs processing necessary for communication in a single frequency band and the function of the common data processing unit 153 that performs processing common to communications in a plurality of frequency bands may be realized by one data processing unit.

[0116] The signal processing unit 155 includes a transmission signal processing unit and a reception signal processing unit. The transmission signal processing unit performs encoding, interleaving, modulation, etc. on the data unit and adds a physical header to generate a codeword stream. The reception signal processing unit analyzes the physical header and performs demodulation, deinterleaving, decoding, etc. on the codeword stream to generate a data unit. At this time, the reception signal processing unit performs complex channel characteristic estimation and spatial separation processing as needed. The signal processing unit 155 is also called a PHY unit.

[0117] Note that the individual data processing units 154 and signal processing units 155 may be provided as one set for each block surrounded by a broken line, and two or more of these sets may be connected to one wireless interface unit 156 .

[0118] The wireless interface unit 156 includes a transmitting wireless interface unit and a receiving wireless interface unit. The transmitting wireless interface unit performs digital-to-analog signal conversion, filtering, up-conversion and phase control on the codeword stream to generate a transmitting signal. The receiving wireless interface unit performs down-conversion, filtering and analog-to-digital signal conversion on the received signal to generate a codeword stream.

[0119] The amplification unit 157 includes a transmission amplification unit and a reception amplification unit. The transmission amplification unit amplifies the signal input from the wireless interface unit 156, and the reception amplification unit amplifies the signal input from the antenna 140. A part of the amplification unit 157 may be configured outside the wireless communication unit 110, or a part thereof may be included in the wireless interface unit 156.

[0120] Hereinafter, the wireless interface unit 156 and the amplification unit 157 are collectively referred to as an RF unit.

[0121] The control unit 120 controls the entire wireless communication unit 110 and the communication control unit 151. The control unit 120 may perform a part of the processing performed by the communication control unit 151. Furthermore, the control unit 120 and the communication control unit 151 may be integrally configured.

[0122] The storage unit 130 holds information used by the wireless communication unit 110 and the control unit 120. The storage unit 130 may perform a part of the processing performed by the communication storage unit 152. Furthermore, the storage unit 130 and the communication storage unit 152 may be configured integrally.

[0123] Note that the wireless communication unit 110 is implemented by, for example, one or more large-scale integrated circuits (LSIs).

[0124] The configuration of the wireless communication unit 110 is an example and is not limited thereto. For example, there may be a case where the wireless communication unit 110 includes two or four or more APs belonging to the AP MLD 1. In the case where the wireless communication unit 110 includes three or more APs belonging to the AP MLD 1, some of the multiple APs may share the same antenna 140 via a frequency division unit.

[0125] - Non-AP MLD 2 configuration (compatible with EMLSR operation)

[0126] Fig.12 is a block diagram illustrating a functional configuration example of a non-AP MLD 2 compatible with the EMLSR operation.

[0127] The non-AP MLD 2 includes a wireless communication unit 210 , a control unit 220 , a storage unit 230 , and an antenna 240 .

[0128] The wireless communication unit 210 includes a communication control unit 251 , a communication storage unit 252 , a common data processing unit 253 , an individual data processing unit 254 , a signal processing unit 255 , a wireless interface unit 256 , and an amplification unit 257 .

[0129] The wireless communication unit 210 includes an individual data processing unit 254 for each link. The individual data processing unit 254 on the left side of the figure operates as non-AP STA 1, the individual data processing unit 254 in the center of the figure operates as non-AP STA 2, and the individual data processing unit 254 on the right side of the figure operates as non-AP STA 3.

[0130] Each functional block of the wireless communication unit 210 basically has the same functions as the wireless communication unit 110 ( Fig.11 However, the wireless communication unit 210 is different from the wireless communication unit 110 of the AP MLD 1 in that it includes only one signal processing unit 255 and two simple signal processing units 255.

[0131] The simple signal processing unit 255s may perform similar processing as the signal processing unit 255, but has limited functionality compared to the signal processing unit 255. For example, the simple signal processing unit 255s supports only a part of the modulation schemes or frame formats supported by the signal processing unit 255 as usable modulation schemes or transmittable / receivable frame formats.

[0132] On the other hand, since the processing capability of the simple signal processing unit 255s as a functional block is reduced, there is also an advantage that implementation is facilitated and power consumption can be suppressed. In a wireless communication terminal such as a small terminal in which it is difficult to implement a plurality of signal processing units, it is expected that a simple signal processing unit is implemented instead of a signal processing unit, such as Fig.12 The simple signal processing unit 255s is also called a small PHY unit or a simple PHY unit.

[0133] Switches SW are provided between the individual data processing unit 254 and the signal processing unit 255 and simple signal processing unit 255s and between the signal processing unit 255 and simple signal processing unit 255s and the wireless interface unit 256. The non-APMLD 2 determines which function blocks are used in which link at the time of state transition and switches the switches SW.

[0134] In the present technology, the communication control unit 251 controls each processing unit to notify (send to the APMLD 1) information about the transition time of each link in the own terminal. For example, the transition time of each link is calculated based on at least one of the switching time of the operating frequency of the RF unit, the switching time of the connection destination of each of the RF unit, the PHY unit, the simple PHY unit, and the lower MAC unit, and the start-up time of the signal processing unit 255 and the simple signal processing unit 255s.

[0135] Note that, Fig.12 The functions of the control unit 220, the storage unit 230 and the antenna 240 are similar to those of Figure 2 The functions of the control unit 120, the storage unit 130 and the antenna 140 are substantially similar, so the description thereof is omitted.

[0136] - Non-AP MLD 2 configuration (compatible with EMLMR operation)

[0137] Fig.13 is a block diagram illustrating a functional configuration example of a non-AP MLD 2 compatible with EMLMR operation. Fig.13 In, with Fig.12 The same components are denoted by the same reference numerals. Redundant descriptions are appropriately omitted.

[0138] Fig.13 The wireless communication unit 210 and Fig.12 The wireless communication unit 210 of FIG. 1 is different in that it does not include a simple signal processing unit 255 s but includes three signal processing units 255 .

[0139] Switches SW are provided between the individual data processing unit 254 and the signal processing unit 255 and between the signal processing unit 255 and the wireless interface unit 256. The non-AP MLD 2 determines which function block is used in which link at the time of state transition, and switches the switches SW.

[0140] - Non-AP MLD 2 Operation

[0141] refer to Fig.14 , the flow of an operation in which the non-AP MLD 2 notifies the AP MLD 1 of information on the transition time of the state in the own terminal will be described.

[0142] In step S1, the wireless communication unit 210 (communication control unit 251) acquires information for calculating the transition time of each link in the own terminal. As the information for calculating the transition time of each link, for example, the switching time of the operating frequency of each RF unit, the switching time of the connection destination of each of the RF unit, the simple PHY unit, the PHY unit, and the lower MAC unit, and the startup time of the simple PHY unit and the PHY unit are acquired.

[0143] In step S2, the wireless communication unit 210 notifies (transmits to the AP MLD 1) information on the transition time of each link in the own terminal.

[0144] In the case where the non-AP MLD 2 is compatible with EMLSR operation, the information about the transition time of each link includes, for example, at least one of information for identifying the link before the transition and the link after the transition, information about a first transition time required for transitioning from a multi-link scanning state to a single-link sending / receiving state of each link, and information about a second transition time required for transitioning from the single-link sending / receiving state of each link to the multi-link scanning state.

[0145] In the case where non-AP MLD 2 is compatible with EMLMR operation, the information about the transition time of each link includes at least one of information for identifying a link before the transition and a link after the transition, information about a first transition time required for transitioning from a multi-link operation state to a single-link operation state of each link, and information about a second transition time required for transitioning from a single-link operation state of each link to a multi-link operation state.

[0146] In the case where the non-AP MLD 2 can simultaneously perform switching of the operating frequency of each RF unit, switching of the switch SW, and startup of the simple PHY unit and the PHY unit, the first transition time and the second transition time are the maximum times among the switching time of the operating frequency of each RF unit, the switching time of the connection destination of each of the RF unit, the PHY unit, the simple PHY unit and the lower MAC unit, and the startup time of the simple PHY unit and the PHY unit.

[0147] In the case where the non-AP MLD 2 cannot simultaneously perform switching of the operating frequency of each RF unit, switching of the switch SW, and startup of the simple PHY unit and the PHY unit, the first transition time and the second transition time are the total time of the switching time of the operating frequency of each RF unit, the switching time of the connection destination of each of the RF unit, the PHY unit, the simple PHY unit and the lower MAC unit, and the startup time of the simple PHY unit and the PHY unit.

[0148] For example, the AP MLD 1 is notified of information on the transition time of each link by using a multilink element.

[0149] Fig.15 is a diagram illustrating an example of a configuration example of a multilink element.

[0150] like Fig.15 As indicated in the upper part of , the multilink element includes element ID, length, element ID extension, multilink control, common information and link information.

[0151] The element ID is information indicating the type of the element. In the present embodiment, an identifier indicating a multi-link element is described.

[0152] The length is information indicating the length of the element.

[0153] The element ID extension is information indicating the type of element added to the element ID.

[0154] The multilink control is information indicating the type of the multilink element and information indicating what kind of information is written in the common information field.

[0155] Common information is information commonly used in each link in MLD.

[0156] The link information is information that is different for each link and includes one or more sub-elements.

[0157] like Fig.15 As indicated in the middle, the sub-elements of Link Information include sub-elements ID, Length, STA Control, STA Information, and STA Profile.

[0158] The child element ID is information indicating the type of the child element.

[0159] The length is information indicating the length of the sub-element.

[0160] STA Control is information indicating a link ID for identifying a link and information indicating what information is written in STA Information.

[0161] like Fig.15 Indicated at the bottom, STA control includes link ID, full profile, MAC address presence, beacon interval presence, DTIM information presence, NSTR link pair presence, NSTR bitmap size, each STA EML delay presence and reservation.

[0162] The link ID is information for identifying a link.

[0163] The full profile is information indicating that all information that can be written is described in the STA information.

[0164] The MAC address exists, the beacon interval exists, the DTIM information exists, and the NSTR link pair exists are information indicating that the MAC address, the beacon interval, the DTIM information, and the NSTR link pair are written in the STA information.

[0165] The NSTR bitmap size is information indicating the length of a bitmap for indicating an NSTR link pair.

[0166] Each STA EML delay presence is information indicating that information on the transition time of each link is written in the STA information.

[0167] A reservation may include any information.

[0168] The STA information in the link information sub-element is the information of each link. Fig.15 As indicated in the lower part, the STA information includes each STA EML delay.

[0169] Each STA EML delay is information about the transition time of each link in the EML mode (EMLSR mode or EMLMR mode).

[0170] As each STA EML delay, a pair of information indicating a link before transition and information about the transition time of each link may be written. As each STA EML delay, each of information about the transition time of each link in EMLSR mode and information about the transition time of each link in EMLMR mode may be written. As each STA EML delay, information indicating whether to operate the PHY unit when performing channel scanning may be written, and information about the transition time of each link in each case of operating the PHY unit and not operating the PHY unit may be written.

[0171] The STA profile in the sub-element of the link information is information other than the sub-element ID, length, STA control, and STA information. For example, the STA profile is information indicating EDCA parameters.

[0172] Note that the method of notifying the information about the transition time of each link is not limited to the method using the multilink element, and the information about the transition time of each link can be notified using a newly defined frame. In addition, the information about the transition time of each link can be written in any of the newly defined fields, elements, and sub-elements in the EML OMN frame. The information about the transition time of each link can be divided into a plurality of frames and notified.

[0173] -AP MLD 1 Operation

[0174] Next, refer to Fig.16 The flow of operation of AP MLD 1 determining a link for frame transmission will be described with reference to the flowchart of FIG.

[0175] In step S11, the wireless communication unit 110 (communication control unit 151) acquires information about the transition time of each link in the non-AP MLD 2. In addition, the wireless communication unit 110 acquires information about the number of simple PHY units and PHY units provided in the non-AP MLD 2. The simple PHY unit and the number of PHY units are written in a multilink element or an EML OMN frame, for example.

[0176] In step S12 , the wireless communication unit 110 determines a link for frame transmission to the non-AP MLD 2 based on the transmission waiting time (backoff time) of each link for transmitting a frame and information on the transition time of each link in the non-AP MLD 2 .

[0177] Specifically, when performing the EMLSR operation, the wireless communication unit 110 determines the link that sends the MU-RTS frame or the BSRP trigger frame as the link that sends the MU-RTS frame or the BSRP trigger frame, by which the total time of the sending waiting time of each link and the first transition time required for the non-AP MLD 2 to transition from the multi-link scanning state to the single-link sending / receiving state is the shortest.

[0178] When performing the EMLMR operation, the wireless communication unit 110 determines a link that minimizes the total of the transmission waiting time of each link and the first transition time required for the non-AP MLD 2 to transition from the multi-link operation state to the single-link operation state as a link for transmitting the PPDU.

[0179] Furthermore, in step S12 , the wireless communication unit 110 determines the length of padding added to the PPDU based on the information on the first transition time of each link.

[0180] In step S13, the wireless communication unit 110 transmits a PPDU to the non-AP MLD 2. Here, in the case of performing the EMLSR operation, the wireless communication unit 110 transmits a PPDU including a MU-RTS frame or a BSRP trigger frame. In the case of performing the EMLMR operation, the wireless communication unit 110 transmits a PPDU including, for example, a data frame.

[0181] In the PPDU sent to the non-AP MLD 2, padding having a length according to the transition time to the single link transmission / reception state corresponding to the link for frame transmission is added so that a CTS frame or a BSR frame (or an ACK frame) can be sent after the non-AP MLD 2 transitions to the single link transmission / reception state (or single link operation state) corresponding to the link for frame transmission.

[0182] According to the above configuration and processing, during the execution of the EMLSR operation or the EMLMR operation, the AP MLD 1 can determine the link for which the time for waiting for the non-AP MLD 2 to transition from the multi-link state to the single-link state is the shortest as the link for frame transmission, thereby making it possible to reduce the waiting time of the AP MLD 1. In addition, it is possible to optimize the waiting time of the AP MLD 1 by adding padding to the PPDU, the padding having a length corresponding to the transition time to the single-link transmission / reception state corresponding to the link for frame transmission.

[0183] By reducing and optimizing the waiting time of the AP MLD 1, it is possible to improve the communication efficiency during the EMLSR operation or the EMLMR operation.

[0184] <3. First Embodiment (Example of EMLSR Operation)>

[0185] Fig.17 It is a sequence diagram of the EMLSR operation performed by the wireless communication system of the present technology.

[0186] In this embodiment, it is assumed that when non-AP MLD 2 is not in EMLSR mode, it is in link 3 ( Figure 4 )’s single link sending / receiving status.

[0187] First, the non-AP MLD 2 writes information about a first transition time required to transition from a multi-link scanning state to a single-link transmission / reception state of each link and information about a second transition time required to transition from a single-link transmission / reception state of each link to a multi-link scanning state in a multi-link element.

[0188] In the multi-link element, as information about the first transition time of each link, six pieces of information about transition times when transitioning from link 1 to link 2, from link 1 to link 3, from link 2 to link 1, from link 2 to link 3, from link 3 to link 1, and from link 3 to link 2 are written. For example, the transition time required to transition from a state in which the non-AP MLD 2 can scan link 1 to a single-link transmission / reception state of link 2 is calculated based on the time to switch the operating frequency of the RF unit from link 1 to link 2, the time to switch the connection destination of the RF unit from a simple PHY unit to a PHY unit, and the time to switch the connection destination of the PHY unit to a lower MAC unit corresponding to link 2.

[0189] In the multi-link element, as information about the second transition time of each link, six pieces of information about the transition time when transitioning from link 1 to link 2, from link 1 to link 3, from link 2 to link 1, from link 2 to link 3, from link 3 to link 1, and from link 3 to link 2 are written. For example, the transition time required for transitioning from the single link transmission / reception state of link 3 to the state in which the non-AP MLD 2 can scan link 1 is calculated based on the time to switch the operating frequency of the RF unit from link 3 to link 1, the time to start the simple PHY unit, the time to switch the connection destination of the RF unit from the PHY unit to the simple PHY unit, and the time to switch the connection destination of the simple PHY unit to the lower MAC unit corresponding to link 1.

[0190] Next, non-AP MLD 2 sends the multilink element to AP MLD 1 by using link 3 .

[0191] Next, non-AP MLD 2 transmits an EML OMN frame to AP MLD 1 by using Link 3, in which the EMLSR Mode subfield is set to 1, and Links 1 to 3 are designated as EMLSR links.

[0192] The AP MLD 1 which has received the EML OMN frame returns the EML OMN frame in which the EMLSR Mode subfield is set to 1 to the non-AP MLD 2 by using the link 3 .

[0193] The non-AP MLD 2 that receives the EML OMN frame changes from the single link sending / receiving state ( Figure 4 ) to the multi-link scanning state ( Figure 5 ), and starts channel scanning in Link 1 to Link 3 by using at least one of the PHY unit and the Simple PHY unit, and waits for reception of a MU-RTS frame (BSRP trigger frame). Specifically, the operating frequency of each RF unit is switched to Link 1 to Link 3, and each Simple PHY unit is started. In addition, the connection destination of each RF unit, each Simple PHY unit, PHY unit, and each lower MAC unit is switched.

[0194] Note that it is also possible for the AP MLD 1 or the non-AP MLD 2 to determine the link to be scanned during the EMLSR operation (EMLSR link) based on information about the transition time required for the non-AP MLD 2 to transition from the multi-link scanning state to the single-link sending / receiving state for each link and information about the transition time required for the non-AP MLD 2 to transition from the single-link sending / receiving state for each link to the multi-link scanning state.

[0195] AP MLD 1 determines a link that enables non-AP MLD 2 to start transmitting the data frame of data 1 earliest based on a first transition time required for non-AP MLD 2 to transition from the multi-link scanning state to the single-link transmission / reception state of each link and a transmission waiting time of each link.

[0196] exist Fig.17In the example of FIG. 1 , AP MLD 1 determines that link 1 is the link that enables non-AP MLD 2 to start sending data frames of data 1 at the earliest, and sends a PPDU including a MU-RTS frame to non-AP MLD 2 by using link 1. The PPDU including the MU-RTS frame is sent with padding added. Note that padding can be performed by using a padding field in the MU-RTS frame, or can be performed by using packet extension when configuring the PPDU.

[0197] The non-AP MLD 1 that receives the MU-RTS frame switches the operating frequency of each RF unit to link 1 and switches the connection destination of each RF unit, PHY unit, and lower MAC unit, thereby switching from the multi-link scanning state ( Figure 5 ) changes to the single link transmission / reception state of link 1 ( Figure 6 ). After completing the transition to the single-link transmission / reception state, the non-AP MLD 1 transmits a CTS frame to the AP MLD 1 by using the link 1.

[0198] The AP MLD 1 which has received the CTS frame transmits a plurality of spatially multiplexed streams (data frames of data 1 ) to the non-AP MLD 2 by using the link 1 .

[0199] The non-AP MLD 2 receiving the data frame of the data 1 transmits an ACK frame to the AP MLD 1 by using the link 1 .

[0200] After the frame exchange with the AP MLD 1 is completed, the non-AP MLD 2 transits from the single-link transmission / reception state to the multi-link scanning state.

[0201] The AP MLD 1 waits so as not to transmit the MU-RTS frame in a period in which the non-AP MLD 2 transits from the single-link transmission / reception state to the multi-link scanning state based on the information on the second transition time of each link.

[0202] As described above, during the execution of the EMLSR operation, AP MLD 1 can determine the link with the shortest waiting time for the non-AP MLD 2 to transition from the multi-link scanning state to the single-link transmission / reception state as the link for sending PPDU, thereby becoming possible to reduce the waiting time of AP MLD 1 and improve communication efficiency.

[0203] <4. Second Embodiment (Example of EMLMR Operation)>

[0204] Fig.18 It is a sequence diagram of EMLMR operation performed by the wireless communication system of the present technology.

[0205] In this embodiment, it is assumed that the non-AP MLD 2 is in a multi-link operation state when not in the EMLMR mode ( Fig. 9 ).

[0206] First, the non-AP MLD 2 writes information about a second transition time required to transition from the multilink operation state to the single link operation state of each link and information about a second transition time required to transition from the single link operation state of each link to the multilink operation state in the multilink element.

[0207] In the multi-link element, as information about the first transition time of each link, six pieces of information about transition times when transitioning from link 1 to link 2, from link 1 to link 3, from link 2 to link 1, from link 2 to link 3, from link 3 to link 1, and from link 3 to link 2 are written. For example, the transition time required to transition from a state in which the non-AP MLD 2 can scan link 3 to a single-link operation state of link 2 is calculated based on the time to switch the operating frequency of the RF unit from link 1 to link 2, the time to switch the connection destination of the RF unit to one PHY unit, and the time to switch the connection destination of the PHY unit to the lower MAC unit corresponding to link 2.

[0208] In the multi-link element, as information about the second transition time of each link, six pieces of information about the transition time when transitioning from link 1 to link 2, from link 1 to link 3, from link 2 to link 1, from link 2 to link 3, from link 3 to link 1, and from link 3 to link 2 are written. For example, the transition time required for transitioning from the single link operation state of link 3 to the state in which the non-AP MLD 2 can scan link 1 is calculated based on the time to switch the operating frequency of the RF unit from link 3 to link 1, the time to start the PHY unit, the time to switch the PHY unit as the connection destination of the RF unit, and the time to switch the connection destination of the PHY unit connected to the RF unit to the lower MAC unit corresponding to link 1.

[0209] Next, non-AP MLD 2 sends a multilink element to AP MLD 1.

[0210] Next, non-AP MLD 2 sends an EML OMN frame to AP MLD 1, in which the EMLMR Mode subfield is set to 1 and Link 1 to Link 3 are designated as EMLMR links.

[0211] The AP MLD 1 that has received the EML OMN frame returns the EML OMN frame in which the EMLMR Mode subfield is set to 1 to the non-AP MLD 2.

[0212] The non-AP MLD 2 receiving the EML OMN frame starts channel scanning at Link 1 to Link 3 by using each PHY unit and waits for reception of a PPDU.

[0213] AP MLD 1 determines a link that enables non-AP MLD 2 to start transmission of the data frame of DATA 1 earliest based on the first transition time required for non-AP MLD 2 to transition from the multi-link operation state to the single-link operation state of each link and the transmission wait time of each link.

[0214] exist Fig.18 In the example of , APMLD 1 determines that link 1 is the link that enables non-APMLD 2 to start transmission of the data frame of data 1 at the earliest, and transmits a PPDU including a data frame of data 0 to non-AP MLD 2 by using link 1. The PPDU including the data frame of data 0 is transmitted with padding added. In the EMLMR operation, the PHY unit is used to perform scanning at each link, and therefore, even when non-AP MLD 2 is in a multi-link operation state, AP MLD 1 can transmit frames other than MU-RTS frames and BSRP trigger frames to non-AP MLD 2.

[0215] The non-AP MLD 1 that receives the data frame of data 0 switches the operating frequency of each RF unit to link 1 and switches the connection destination of each RF unit, PHY unit, and lower MAC unit, thereby switching from a multi-link operation state ( Fig. 9 ) to the single link operation state of link 1 ( Fig.10 ). After completing the transition to the single-link transmission / reception state, the non-AP MLD1 transmits an ACK frame to the AP MLD1 by using the link1.

[0216] The AP MLD 1 which has received the ACK frame transmits a plurality of spatially multiplexed streams (data frames of data 1 ) to the non-AP MLD 2 by using the link 1 .

[0217] The non-AP MLD 2 receiving the data frame of the data 1 transmits an ACK frame to the AP MLD 1 by using the link 1 .

[0218] After the frame exchange with the AP MLD 1 is completed, the non-AP MLD 2 transits from the single-link operation state to the multi-link operation state.

[0219] The AP MLD 1 waits so as not to transmit a frame within a transition period in which the non-AP MLD 2 transitions from the single-link operation state to the multi-link operation state based on the information on the second transition time of each link.

[0220] As described above, during the EMLMR operation, AP MLD 1 can determine the link that minimizes the waiting time for non-AP MLD 2 to transition from a multi-link operation state to a single-link operation state as the link for frame transmission, thereby making it possible to reduce the waiting time of AP MLD 1 and improve communication efficiency.

[0221] Note that the AP MLD 1 or the non-AP MLD 2 can determine on which link to perform the EMLMR operation and the maximum number of streams to be used under the single-link operation state and the modulation and coding scheme (MCS) based on the first transition time information required to transition from the multi-link operation state to the single-link operation state of each link and the second transition time information required to transition from the single-link operation state of each link to the multi-link operation state in the non-AP MLD 2.

[0222] Note that the effects described in this specification are merely examples and are not restrictive, and other effects may be provided.

[0223] Furthermore, the embodiments to which the present technology is applied are not limited to the above-described embodiments, and various modifications are possible without departing from the scope of the present technology.

[0224] <Configuration combination example>

[0225] The present technology may also be configured as follows. (1)

[0227] A wireless communication device, comprising:

[0228] A communication control unit that determines a link for frame transmission to a wireless communication terminal from among a plurality of links based on information about a first transition time for each of the plurality of links, the first transition time being required for the wireless communication terminal to transition from a multi-link state in which communication is performed by using the plurality of links to a single-link state in which communication can be performed by using any one of the links. (2)

[0230] The wireless communication device according to (1),

[0231] The communication control unit performs control to cause the wireless communication device to receive information on the first transition time transmitted from the wireless communication terminal. (3)

[0233] The wireless communication device according to (1) or (2), wherein

[0234] The communication control unit determines a link to be used for frame transmission based on a first transition time of each of the links and a transmission wait time of each of the links for transmitting a frame to the wireless communication terminal. (4)

[0236] The wireless communication device according to (3),

[0237] The communication control unit determines a link that minimizes the total time of the first transition time and the transmission waiting time as a link to be used for frame transmission. (5)

[0239] The wireless communication device according to any one of (1) to (4),

[0240] When the wireless communication terminal is in the multi-link state, the communication control unit performs control to cause the wireless communication device to transmit a PPDU including a MU-RTS frame or a BSRP trigger frame to the wireless communication terminal by using a link for frame transmission. (6)

[0242] The wireless communication terminal according to any one of (1) to (5),

[0243] The wireless communication terminal is provided with an RF unit, a PHY unit, a simple PHY unit for performing channel scanning, and a MAC unit, and

[0244] The first transition time is calculated based on at least any one of a switching time of an operating frequency of the RF unit, a switching time of a connection destination of each of the RF unit, the PHY unit, the Simple PHY unit, and the MAC unit, and a startup time of the PHY unit or the Simple PHY unit. (7)

[0246] The wireless communication device according to any one of (1) to (5),

[0247] When the wireless communication terminal is in the multi-link state, the communication control unit performs control to cause the wireless communication device to transmit a PPDU including a data frame to the wireless communication terminal by using a link for frame transmission. (8)

[0249] The wireless communication terminal according to any one of (1) to (5) and (7), wherein

[0250] The wireless communication terminal is provided with an RF unit, a PHY unit and a MAC unit, and

[0251] The first transition time is calculated based on at least any one of a switching time of an operating frequency of the RF unit, a switching time of a connection destination of each of the RF unit, the PHY unit, and the MAC unit, and a startup time of the PHY unit. (9)

[0253] The wireless communication device according to any one of (1) to (8),

[0254] The communication control unit performs control to cause the wireless communication device to transmit a PPDU to which padding having a length corresponding to the information on the first transition time is added to the wireless communication terminal by using a link for frame transmission. (10)

[0256] The wireless communication device according to any one of (1) to (9),

[0257] The communication control unit performs control based on information about a second transition time for each of the links to cause the wireless communication device to wait without sending frames during a period in which the wireless communication terminal transitions from a single-link state to a multi-link state, wherein the second transition time is required for the wireless communication terminal to transition from a single-link state to a multi-link state. (11)

[0259] The wireless communication device according to any one of (1) to (10),

[0260] The single link state is a state in which a plurality of spatially multiplexed streams can be transmitted and received by using any one of the plurality of links. (12)

[0262] A wireless communication method performed by a wireless communication device, comprising:

[0263] A link for transmitting a frame to a wireless communication terminal is determined from among the plurality of links based on information about a first transition time for each of the plurality of links, wherein the first transition time is required for the wireless communication terminal to transition from a multi-link state in which communication is performed by using the plurality of links to a single-link state in which communication can be performed by using any one of the links. (13)

[0265] A wireless communication terminal, comprising:

[0266] a communication control unit that performs control so that the wireless communication terminal communicates with the wireless communication device, wherein

[0267] The communication control unit performs control so that the wireless communication terminal transmits information about a first transition time for each of a plurality of links to the wireless communication device, the first transition time being required for the wireless communication terminal to transition from a multi-link state in which communication is performed by using the plurality of links to a single-link state in which communication can be performed by using any one of the links. (14)

[0269] The wireless communication terminal according to (13),

[0270] The communication control unit performs control so that the wireless communication terminal performs channel scanning of the plurality of links by using at least any one of a PHY unit and a simple PHY unit for performing channel scanning in a multi-link state. (15)

[0272] The wireless communication terminal according to (14),

[0273] The first transition time is calculated based on at least any one of a switching time of an operating frequency of the RF unit, a switching time of a connection destination of each of the RF unit, the PHY unit, the Simple PHY unit, and the MAC unit, and a startup time of the PHY unit or the Simple PHY unit. (16)

[0275] The wireless communication terminal according to (15),

[0276] The first transition time is a total time or a maximum time of a switching time of an operating frequency of the RF unit, a switching time of a connection destination of each of the RF unit, the PHY unit, the Simple PHY unit, and the MAC unit, and a startup time of the PHY unit or the Simple PHY unit. (17)

[0278] The wireless communication terminal according to any one of (13) to (16),

[0279] The information about the first transition time includes information indicating a link before the transition and information indicating a link after the transition. (18)

[0281] The wireless communication terminal according to any one of (13) to (17),

[0282] The communication control unit performs control to cause the wireless communication terminal to transmit information on a second transition time required for the wireless communication terminal to transition from a single-link state to a multi-link state to the wireless communication device. (19)

[0284] The wireless communication device according to any one of (13) to (18),

[0285] The single link state is a state in which a plurality of spatially multiplexed streams can be transmitted and received by using any one of the plurality of links. (20)

[0287] A wireless communication method performed by a wireless communication terminal communicating with a wireless communication device, comprising:

[0288] Information about a first transition time for each of a plurality of links is transmitted to the wireless communication device, the first transition time being required for the wireless communication terminal to transition from a multi-link state in which communication is performed by using the plurality of links to a single-link state in which communication can be performed by using any one of the links. Reference numerals list

[0289] 1AP MLD

[0290] 2 Non-AP MLD

[0291] 110 Wireless Communication Unit

[0292] 120 control unit

[0293] 130 storage units

[0294] 140 antenna

[0295] 151 Communication control unit

[0296] 152 Communication storage unit

[0297] 153 shared data processing unit (upper MAC unit)

[0298] 154 individual data processing unit (lower MAC unit)

[0299] 155 signal processing unit (PHY unit)

[0300] 156 Wireless Interface Unit

[0301] 157 Amplification Unit

[0302] 210 Wireless Communication Unit

[0303] 220 control unit

[0304] 230 storage units

[0305] 240 Antenna

[0306] 251 Communication Control Unit

[0307] 252 Communication Storage Unit

[0308] 253 shared data processing unit (upper MAC unit)

[0309] 254 individual data processing units (lower MAC units)

[0310] 255 signal processing unit (PHY unit)

[0311] 255s Simple Signal Processing Unit (Simple PHY Unit, Small PHY Unit)

[0312] 256 wireless interface units

[0313] 257 Amplification Unit

Claims

1. A wireless communication device, comprising: A communication control unit that determines a link for frame transmission to a wireless communication terminal from among a plurality of links based on information about a first transition time for each of the plurality of links, the first transition time being required for the wireless communication terminal to transition from a multi-link state in which communication is performed by using the plurality of links to a single-link state in which communication can be performed by using any one of the links.

2. The wireless communication device according to claim 1, wherein The communication control unit performs control to cause the wireless communication device to receive information on the first transition time transmitted from the wireless communication terminal.

3. The wireless communication device according to claim 1, wherein The communication control unit determines a link to be used for frame transmission based on a first transition time of each of the links and a transmission wait time of each of the links for transmitting a frame to the wireless communication terminal.

4. The wireless communication device according to claim 3, wherein The communication control unit determines a link that minimizes the total time of the first transition time and the transmission waiting time as a link to be used for frame transmission.

5. The wireless communication device according to claim 1, wherein When the wireless communication terminal is in the multi-link state, the communication control unit performs control to cause the wireless communication device to transmit a PPDU including a MU-RTS frame or a BSRP trigger frame to the wireless communication terminal by using a link for frame transmission.

6. The wireless communication terminal according to claim 1, wherein The wireless communication terminal is provided with an RF unit, a PHY unit, a simple PHY unit for performing channel scanning, and a MAC unit, and The first transition time is calculated based on at least any one of a switching time of an operating frequency of the RF unit, a switching time of a connection destination of each of the RF unit, the PHY unit, the Simple PHY unit, and the MAC unit, and a startup time of the PHY unit or the Simple PHY unit.

7. The wireless communication device according to claim 1, wherein When the wireless communication terminal is in the multi-link state, the communication control unit performs control to cause the wireless communication device to transmit a PPDU including a data frame to the wireless communication terminal by using a link for frame transmission.

8. The wireless communication terminal according to claim 1, wherein The wireless communication terminal is provided with an RF unit, a PHY unit and a MAC unit, and The first transition time is calculated based on at least any one of a switching time of an operating frequency of the RF unit, a switching time of a connection destination of each of the RF unit, the PHY unit, and the MAC unit, and a startup time of the PHY unit.

9. The wireless communication device according to claim 1, wherein The communication control unit performs control to cause the wireless communication device to transmit a PPDU to which padding having a length corresponding to the information on the first transition time is added to the wireless communication terminal by using a link for frame transmission.

10. The wireless communication device according to claim 1, wherein The communication control unit performs control based on information about a second transition time for each of the links to cause the wireless communication device to wait without sending frames during a period in which the wireless communication terminal transitions from a single-link state to a multi-link state, wherein the second transition time is required for the wireless communication terminal to transition from a single-link state to a multi-link state.

11. The wireless communication device according to claim 1, wherein The single link state is a state in which a plurality of spatially multiplexed streams can be transmitted and received by using any one of the plurality of links.

12. A wireless communication method performed by a wireless communication device, comprising: A link for transmitting a frame to a wireless communication terminal is determined from among the plurality of links based on information about a first transition time for each of the plurality of links, wherein the first transition time is required for the wireless communication terminal to transition from a multi-link state in which communication is performed by using the plurality of links to a single-link state in which communication can be performed by using any one of the links.

13. A wireless communication terminal, comprising: a communication control unit that performs control so that the wireless communication terminal communicates with the wireless communication device, wherein The communication control unit performs control so that the wireless communication terminal transmits information about a first transition time for each of a plurality of links to the wireless communication device, the first transition time being required for the wireless communication terminal to transition from a multi-link state in which communication is performed by using the plurality of links to a single-link state in which communication can be performed by using any one of the links.

14. The wireless communication terminal according to claim 13, wherein The communication control unit performs control so that the wireless communication terminal performs channel scanning of the plurality of links by using at least any one of a PHY unit and a simple PHY unit for performing channel scanning in a multi-link state.

15. The wireless communication terminal according to claim 14, wherein The first transition time is calculated based on at least any one of a switching time of an operating frequency of the RF unit, a switching time of a connection destination of each of the RF unit, the PHY unit, the Simple PHY unit, and the MAC unit, and a startup time of the PHY unit or the Simple PHY unit.

16. The wireless communication terminal according to claim 15, wherein The first transition time is a total time or a maximum time of a switching time of an operating frequency of the RF unit, a switching time of a connection destination of each of the RF unit, the PHY unit, the Simple PHY unit, and the MAC unit, and a startup time of the PHY unit or the Simple PHY unit.

17. The wireless communication terminal according to claim 13, wherein The information about the first transition time includes information indicating a link before the transition and information indicating a link after the transition.

18. The wireless communication terminal according to claim 13, wherein The communication control unit performs control to cause the wireless communication terminal to transmit information on a second transition time required for the wireless communication terminal to transition from a single-link state to a multi-link state to the wireless communication device.

19. The wireless communication device according to claim 13, wherein The single link state is a state in which a plurality of spatially multiplexed streams can be transmitted and received by using any one of the plurality of links.

20. A wireless communication method performed by a wireless communication terminal communicating with a wireless communication device, comprising: Information about a first transition time for each of a plurality of links is transmitted to the wireless communication device, the first transition time being required for the wireless communication terminal to transition from a multi-link state in which communication is performed by using the plurality of links to a single-link state in which communication can be performed by using any one of the links.

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