Wireless communication device and wireless communication method

Abstract

The present invention relates to a wireless communication device and a wireless communication method. The influence caused by inter-link interference can be suppressed in multi-link communication. The wireless communication device receives the first information that can identify that the other wireless communication device can operate at the second frequency and the second information that can identify that the other wireless communication device has restrictions on sending and receiving between the second frequency and the first frequency from other wireless communication devices at the first frequency, sets any one of the first frequency or the second frequency as a primary frequency to notify other wireless communication devices, connects with other wireless communication devices at the first frequency and the second frequency, and obtains access rights to frames addressed to other wireless communication devices at secondary frequencies other than the primary frequency among the first frequency or the second frequency when the second information is received, depending on whether the destination address or source address of the communication via the primary frequency contains the address of the other wireless communication device.

Description

[0001] This application is based on Japanese Patent Application (2020-169244) (filing date: October 6, 2020) and claims priority from the Japanese Patent Application (2020-169244), the entire contents of which are incorporated herein by reference. Technical Field

[0002] Embodiments of the present invention relate to a wireless communication device and a wireless communication method for performing multi-link communication. Background Art

[0003] It is known that there is multi-link communication that uses multiple wireless links to communicate between wireless communication devices. When multiple wireless links are used to independently transmit and receive, the frequency band becomes wider and the throughput is improved. However, sometimes, due to interference between wireless links, it is impossible to independently transmit and receive using multiple wireless links. Summary of the invention

[0004] An object of the present invention is to provide a wireless communication apparatus and a wireless communication method capable of suppressing the influence of interference between links in multi-link communication.

[0005] A wireless communication device according to an embodiment, wherein:

[0006] The wireless communication device receives, from another wireless communication device at a first frequency, first information capable of identifying that the other wireless communication device can operate at a second frequency, and second information capable of identifying that there is a restriction on transmission and reception between the second frequency and the first frequency by the other wireless communication device,

[0007] notifying the other wireless communication device that either the first frequency or the second frequency is set as the primary frequency,

[0008] connecting with the other wireless communication device at the first frequency and the second frequency,

[0009] When the second information is received, access rights to frames addressed to the other wireless communication device at a secondary frequency other than the primary frequency among the first frequency or the second frequency are obtained based on whether the destination address or the source address of the communication via the primary frequency includes the address of the other wireless communication device.

[0010] According to the wireless communication device having the above configuration, it is possible to suppress the influence of interference between links in multi-link communication. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 is a diagram showing an example of a wireless link used in multi-link communication.

[0012] Figure 2 is a diagram showing an example of a wireless communication device that performs multi-link communication.

[0013] Figure 3 This is a diagram showing an example of the format of a beacon frame.

[0014] Figure 4 This is a diagram showing an example of the format of a Reduced Neighbor Report element included in the frame body of a beacon frame.

[0015] Figure 5 This is a diagram showing an example of the format of the Reduced Neighbor Report element in the first example of notifying information for multilink communication.

[0016] Figure 6 This is a diagram showing an example of the format of the Reduced Neighbor Report element in the second example of notifying information for multilink communication.

[0017] Figure 7 This is a diagram showing an example of the format of the Reduced Neighbor Report element in the third example of notifying information for multilink communication.

[0018] Figure 8 This is a table showing the relationship between the value of the TBTT Information Length (target beacon transmission time information length) subfield and the type of subfields included in the TBTT Information (target beacon transmission time information) subfield.

[0019] Fig. 9 This is a diagram showing an example of the format of the Reduced Neighbor Report element in the fourth example of notifying information for multilink communication.

[0020] Fig.10 The diagram shows an example of three wireless links in which Link2 and Link3 are in a non-STR link relationship, and Link1 and the other two wireless links are in a STR link relationship.

[0021] Fig.11 This is a diagram showing an example of the format of the ML element included in the frame body of the association request frame.

[0022] Fig.12This is a diagram showing another example of the state of three wireless links in which Link2 and Link3 are in a non-STR link relationship and Link2 and Link1 are also in a non-STR link relationship.

[0023] Fig.13 is a diagram showing another example of the format of an ML element.

[0024] Fig.14 This is a diagram showing still another example of the format of the ML element.

[0025] Fig.15 This is a diagram showing still another example of the format of the ML element.

[0026] Fig.16 This is a diagram showing still another example of the format of the ML element.

[0027] Fig.17A The diagrams show some examples of the relationship between wireless links that are non-STR and the relationship between wireless links that are STR.

[0028] Fig. 17B The diagrams show some examples of the relationship between wireless links that are non-STR and the relationship between wireless links that are STR.

[0029] Fig. 17C The diagrams show some examples of the relationship between wireless links that are non-STR and the relationship between wireless links that are STR.

[0030] Fig.18A The diagrams show some examples of the relationship between wireless links that are non-STR and the relationship between wireless links that are STR.

[0031] Fig.18B The diagrams show some examples of the relationship between wireless links that are non-STR and the relationship between wireless links that are STR.

[0032] Fig.19 This is a diagram showing still another example of the format of the ML element.

[0033] Fig. 20 is a diagram showing an example of a wireless link.

[0034] Fig.21 This is a diagram showing an example of transmission of the AP MLD to the STA MLD.

[0035] Fig. 22 This is a diagram showing an example of the format of a data frame.

[0036] Fig.23This is a diagram showing an example of the format of the RTS frame.

[0037] Fig.24 is a diagram showing an example of padding based on frame aggregation.

[0038] Fig.25 This is a diagram showing an example of the format of a trigger frame.

[0039] Fig.26 This is a diagram showing an example of the format of the ML element in the second embodiment.

[0040] Fig. 27 This is a diagram showing an example of channels under the wireless LAN standard.

[0041] Fig.28 This is a diagram showing an example of a Status Code in the wireless LAN standard.

[0042] Fig.29 This is a diagram showing an example of Status Code in the third embodiment.

[0043] Fig. 30A This is a diagram showing an example of a table created by the AP MLD according to the fourth embodiment.

[0044] Fig. 30B This is a diagram showing an example of a table created by the AP MLD according to the fourth embodiment.

[0045] Fig.31A This is a diagram showing another example of the table created by the AP MLD according to the fourth embodiment.

[0046] Fig.31B This is a diagram showing another example of the table created by the AP MLD according to the fourth embodiment.

[0047] Fig.32 This is a diagram showing still another example of the table created by the AP MLD according to the fourth embodiment.

[0048] Fig.33 This is a flowchart of an example of the classification process of the STA MLD by the AP MLD in the fourth embodiment.

[0049] Fig.34 This is a diagram showing an example of the Status Code in the sixth embodiment.

[0050] Fig.35 This is a diagram showing an example of the format of the MU EDCA parameter group element according to the seventh embodiment.

[0051] Fig.36This is a diagram showing an example of the Status Code in the ninth embodiment.

[0052] Fig.37 This is a diagram showing an example of Status Code in the tenth embodiment.

[0053] Fig.38 This is a diagram showing an example of a trigger type subfield in the eleventh embodiment.

[0054] Fig.39 It is a diagram showing a first installation example of the antenna in the fifteenth embodiment.

[0055] Fig.40 It is a diagram showing a second installation example of the antenna in the fifteenth embodiment.

[0056] Fig.41 It is a diagram showing a third installation example of the antenna in the fifteenth embodiment.

[0057] Fig.42 It is a diagram showing a fourth installation example of the antenna in the fifteenth embodiment.

[0058] Explanation of symbols

[0059] 22: AP MLD; 24A, 24B: STA MLD; 32, 34: physical processing unit; 36, 38: lower MAC processing unit; 40: upper MAC processing unit; 44: management entity. DETAILED DESCRIPTION

[0060] Hereinafter, with reference to the accompanying drawings, the implementation mode will be described. The following description is an illustration of the device and method for embodying the technical idea of ​​the implementation mode, and the technical idea of ​​the implementation mode is not limited to the structure, shape, configuration, material, etc. of the constituent elements described below. The deformation that can be easily thought of by a person skilled in the art is of course included in the scope of disclosure. In order to make the description clearer, in the accompanying drawings, the size, thickness, plane size or shape of each element is sometimes changed for the actual implementation mode and schematically represented. In a plurality of drawings, elements with different relationship and ratio of each other's size are sometimes included. In a plurality of drawings, the same reference numerals are added to the corresponding elements, and repeated descriptions are sometimes omitted. Sometimes, multiple names are added to several elements, but the examples of these names are only examples, and it does not deny to add other names to these elements. In addition, with respect to elements to which multiple names are not added, it does not deny to add other names. In addition, in the following description, "connection" means not only direct connection, but also connection via other elements.

[0061] Hereinafter, this embodiment will be described in detail with reference to the drawings.

[0062] (First embodiment)

[0063] "Multi-link Communication"

[0064] In multi-link communication, multiple wireless links are used to communicate between wireless communication devices. Multi-link communication is also called multi-link operation (hereinafter referred to as MLO).

[0065] Wireless links correspond to frequency channels in different frequency bands or the same frequency band. In wireless LANs that comply with IEEE802.11 and utilize the 2.4 GHz band, the 5 GHz band, and the 6 GHz band, the frequency channels are determined based on the 20 MHz channel using the channel bonding technology. That is, the channels of the wireless LAN include a 40 MHz channel using two adjacent 20 MHz channels, an 80 MHz channel using four adjacent 20 MHz channels, a 160 MHz channel using eight adjacent 20 MHz channels, or an 80+80 MHz channel using four groups of two adjacent 20 MHz channels. These channels are equivalent to frequency channels of wireless links. In addition, in the future, especially in the 6 GHz band, 320 MHz channels, 160+160 MHz channels, 240 MHz channels, and 160+80 MHz channels are also envisioned as channels for wireless LANs.

[0066] When a wireless link is referred to by other expressions, it is a frequency channel used in a Basic Service Set (hereinafter referred to as BSS), which is a unit of a wireless LAN system composed of an access point (hereinafter referred to as AP) having a medium access control (hereinafter referred to as MAC) address. The frequency channel used in the BSS is notified to the wireless communication device using a beacon frame or a probe response frame using the AP.

[0067] Figure 1 An example of a wireless link used in multi-link communication is shown. Wireless links Link1, Link2, and Link3 set in three frequency bands are used. For example, Link1 is set in the 2.4 GHz frequency band, and the channel width is 20 MHz. Link2 is set in the 5 GHz frequency band, and the channel width is 80 MHz. Link3 is set in the 6 GHz frequency band, and the channel width is 160 MHz.

[0068] Of course, the number of wireless links used in the multi-link is not limited to three, and can be two or more than four. Multiple wireless links can also be set in the same frequency band instead of different frequency bands. For example, two wireless links of a 160MHz channel can be set in the 6GHz frequency band. The frequency band is not limited to the 2.4GHz frequency band, the 5GHz frequency band, and the 6GHz frequency band. If the frequency bands that can be used by the wireless system increase, these can of course be included.

[0069] In addition, regarding the 2.4 GHz band, the channel numbers that can be used without substantial interference are ch.1, ch.6, and ch.11. Channel numbers are added at 5 MHz intervals, so these three channels are 25 MHz intervals. Therefore, under the IEEE802.11 standard, the use of 40 MHz channels is allowed, but the use of channel bonding is inappropriate. Therefore, it is believed that in the 2.4 GHz band, there are more ways to choose to use only one 20 MHz channel.

[0070] 《AP MLD, STA MLD》

[0071] Generally speaking, in the case of multi-link communication, the wireless communication device that plays the role of AP at each wireless link is called AP Multi-link Device (hereinafter referred to as AP MLD), and the wireless communication device that acts as a non-AP (terminal (STA)) in each wireless link is called non-AP MLD. In a wireless LAN that complies with the IEEE802.11 standard, AP is also a type of STA, so a STA that is not an AP is expressed as non-AP. However, non-AP MLD can also be intuitively expressed as STA as the terminal of the other party communicating with AP, so in this specification, for convenience, non-AP is called STA, and non-AP MLD is called STA MLD.

[0072] Wireless communication device

[0073] Figure 2 An example of a wireless communication device that performs multi-link communication is shown.

[0074] AP MLD22 can use multiple wireless links such as Link1 and Link2 to perform multi-link communication with STA MLD24A and 24B. The number of STA MLD24A and 24B is not limited to two, and can be more than three or one. The number of wireless links for multi-link communication is not limited to two, and can be more than three. In the case of using two wireless links for multi-link communication, it is not limited to Link1 and Link2, and can be Link1 and Link3 or Link2 and Link3. The combination of wireless links between AP MLD22 and STA MLD24A can be the same as or different from the combination of wireless links between AP MLD22 and STA MLD24B.

[0075] The basic structure of multi-link communication between AP MLD 22 and STA MLD 24A, 24B is roughly the same. Figure 2 Although not shown, AP MLD22 can also be connected to a wired infrastructure network. In addition, the installation of AP MLD22 and STA MLD24A, 24B changes depending on whether the two wireless links are in a non-STR link relationship or a STR link relationship (details will be described later).

[0076] As a method of implementing multi-link communication, a processing unit and a physical processing unit that control access to a wireless medium for each wireless link are sometimes provided in a wireless communication device. The AP MLD 22 and the STA MLD 24A, 24B respectively include a first physical processing unit (PHY1) 32 for Link 1, a first lower MAC processing unit (LowerMAC1) 36, a second physical processing unit (PHY2) 34 for Link 2, and a second lower MAC processing unit (LowerMAC2) 38, and also include an upper MAC processing unit (UpperMAC) 40 and a management entity 44. The lower MAC processing units 36, 38 correspond to processing units that control access to a wireless medium. The lower MAC processing unit 36 ​​and the physical processing unit 32 of both the AP MLD 22 and the STA MLD 24A, 24B use Link 1, and the lower MAC processing unit 38 and the physical processing unit 34 use Link 2. In addition, the first physical processing unit 32 and the second physical processing unit 34 may also adopt a structure that shares a part of the processing.

[0077] When multi-link communication is performed using three or more wireless links, a number of physical processing units and lower MAC processing units corresponding to the number of links are provided.

[0078] In a wireless LAN that complies with the IEEE802.11 standard, the medium access control (MAC) layer is defined as a place where the following processes are performed: the process of controlling access to the wireless medium and the process of transferring data with the upper logical link control (LLC) layer or queuing data corresponding to power saving operations. The lower MAC processing units 36 and 38 perform the former process, and the upper MAC processing unit 40 performs the latter process. In addition, the division of functions between the upper MAC processing unit 40 and the lower MAC processing units 36 and 38 is not limited to this example, and can also be changed.

[0079] The upper MAC processing unit 40 receives data from the upper layer, and processes the data and the information required for converting it into a data frame as a MAC Service Data Unit (hereinafter referred to as MSDU). Furthermore, the upper MAC processing unit 40 processes the information required to generate a management frame according to the instruction of the management entity 44 (the management entity corresponding to the MAC layer is the MAC Layer Management Entity (hereinafter referred to as MLME)) as a MAC Management Protocol Data Unit (hereinafter referred to as MMPDU).

[0080] The lower MAC processing units 36 and 38 generate a MAC frame (MAC Protocol Data Unit; hereinafter referred to as MPDU) when receiving the MSDU and MMPDU from the upper MAC processing unit 40. The MAC frame includes a MAC header, a Frame Body, and a Frame Check Sequence (hereinafter referred to as FCS).

[0081] The MAC header contains a field indicating the frame type. This field is subdivided into a Type field and a Subtype field.

[0082] The types of MAC frames are roughly classified into data frames, management frames, and control frames. The identification information of these types is recorded in the Type field, and the identification information of more detailed types is recorded in the Subtype field.

[0083] In addition, the MAC header also includes a field for entering a sequence number indicating the order in which a data frame or a management frame is sent. The sequence number is preferably assigned by the upper MAC processing unit 40. In terms of data frames, when the QoS function is supported, the allocation of sequence numbers is divided according to the traffic identifier (Traffic Identifier; hereinafter referred to as TID) and the destination. In terms of management frames, the allocation of sequence numbers is also divided according to the destination. Therefore, a plurality of sequence number spaces are provided for allocating sequence numbers. Generally speaking, the sequence number space is a modulo 4096 counter.

[0084] The FCS includes a 32-bit CRC (cyclic redundancy code) for false detection.

[0085] As described later, in multi-link communication, each lower MAC processing unit 36, 38 has a MAC address. Therefore, when the previous rule is applied, the resolution of each MAC address of the link to which the transmission destination becomes the transmission destination must be set for each transmission destination link. However, in order to flexibly switch the link to send the frame, it is preferable to use the same sequence number for the frame between the links, that is, to share the sequence number space between the links. Therefore, the sequence number space is preferably set for each transmission destination wireless communication device in multi-link communication. As a method of collectively handling the transmission destination wireless communication devices having multiple wireless links, it is considered to use Figure 2 In this way, when the upper layer delivers data to the MAC layer, the MAC address of the upper MAC processing unit 40 can be identified, and data can be allocated to the lower MAC processing units 36 and 38 appropriate for transmission in the upper MAC processing unit 40. As another method, it is conceivable to use any one of the MAC addresses of a plurality of wireless links as a representative of the wireless communication device.

[0086] After performing access control to the wireless medium such as Carrier Sense Multiple Access with CollisionAvoidance (hereinafter referred to as CSMA / CA), the lower MAC processing units 36 and 38 send the MAC frame to the wireless medium via the physical processing units 32 and 34. The MAC frame finally becomes a PHY packet (PHY Protocol Data Unit; hereinafter also referred to as PPDU) in the physical processing units 32 and 34, and is sent to the wireless medium via an antenna not shown. The lower MAC processing units 36 and 38 have different MAC addresses. When generating a MAC frame, the lower MAC processing units 36 and 38 each set the MAC address divided by each wireless link in the source MAC address (Transmitting Address; hereinafter referred to as TA) field of the MAC header. When generating a MAC frame, the lower MAC processing units 36 and 38 set the MAC address on the opposite side in the destination MAC address (Receiving Address; hereinafter referred to as RA) field of the MAC header. In the case of broadcast, each of the lower MAC processing units 36 and 38 sets a broadcast address in RA, and in the case of multicast, each of the lower MAC processing units 36 and 38 sets a multicast address in RA.

[0087] A control frame, which is one type of MAC frame, is a frame related to the depth of operation when accessing a wireless medium, and is therefore preferably generated by the lower MAC processing units 36 and 38. The aforementioned sequence number is not added to the control frame.

[0088] MAC frames such as a beacon frame, a probe request frame, a probe response frame, an authentication frame, an association request frame, and an association response frame are management frames.

[0089] The AP periodically sends beacon frames to inform STAs of BSS operation information, the modulation and coding scheme (MCS) used, etc. The AP in the AP MLD also sends beacon frames. When the AP in the APMLD sends a beacon frame, it also includes information related to the AP MLD as described later. When the STA in the STA MLD receives a beacon frame sent by the AP in the AP MLD, it shares the information in the beacon frame as the STA MLD.

[0090] Regarding the probe request frame, it is a frame used by the STA to request the AP to send the same information as the beacon frame. The probe request frame can be sent from the STA in the STAMLD. In addition, the object of the receiving destination can also be the AP in the AP MLD. Regarding the probe response frame, the AP that receives the probe request frame sends it to the STA as a response. The AP in the AP MLD can send a probe response frame. In addition, the object of the receiving destination can also be the STA in the STA MLD. The probe response frame notifies the same information as the beacon frame. In the case where the AP in the AP MLD sends a probe response frame, it also includes information related to the AP MLD as described later. When the STA in the STA MLD receives the probe response frame sent by the AP in the AP MLD, it shares the information in the probe response frame as the STA MLD.

[0091] The authentication frame, the association request frame, and the association response frame are used in the order in which the AP and STA are connected. When these frames are exchanged between one of the STAs in the STA MLD and the AP in the AP MLD of the same wireless link, this order can be applied to the entire connection between the AP MLD and the STA MLD. That is, the connection establishment between the STA MLD and the AP MLD can be performed via a single wireless link. The authentication frame is used to authenticate the other party and is sent by both the AP and the STA. The association request frame is sent from the STA to the AP to request a connection to the AP. In the case where the association request frame is sent from the STA in the STA MLD to the AP in the AP MLD, the allocation of the wireless link used between the STA MLD and the AP MLD is also requested in the association request frame. The association response frame is sent from the AP to the STA to notify the STA of the acceptance or rejection of the association request from the STA.

[0092] A data frame is basically a frame that stores data delivered from an upper layer. However, in a wireless LAN that complies with the IEEE802.11 standard, there are also data frames that are not generated from an MSDU and have empty data, that is, no Frame Body. In a wireless LAN that complies with the IEEE802.11 standard, a specific example of a data frame is a QoS Null frame. The data frame is used for the purpose of closing in the MAC layer. In particular, the QoS Null frame can set the sequence number to an arbitrary value, so it can also be generated by the lower MAC processing unit 36, 38 regardless of the upper MAC processing unit 40.

[0093] The management entity 44 is equivalent to the Service Management Entity (hereinafter referred to as SME) in the IEEE802.11 standard. It is divided into MLME for the MAC layer and PHY Layer Management Entity (hereinafter referred to as PLME) for the PHY layer. Figure 2 Although not strictly expressed, information is exchanged between the MLME and the upper MAC processing unit 40 , and information is exchanged between the PLME and the physical processing units 32 and 34 .

[0094] Each physical processing unit 32, 34 delivers the payload of the PHY packet received through each wireless link of the multilink communication together with the MCS information used in the reception decoding to the lower MAC processing unit 36, 38. The lower MAC processing unit 36, 38 extracts the MAC frame from the payload. Each physical processing unit 32, 34 also delivers the reception level and reception timing information of the signal that cannot be decoded to the corresponding lower MAC processing unit 36, 38. The lower MAC processing unit 36, 38 uses this information to perform carrier sensing.

[0095] The lower MAC processing units 36 and 38 extract the MAC frame. When the lower MAC processing units 36 and 38 determine that there is no error based on the FCS, they determine whether the MAC frame is addressed to the terminal based on the RA field of the MAC header. If the MAC address of the wireless link is set in the RA field, the lower MAC processing units 36 and 38 each extract the Frame Body from the MAC frame, and use the information in the MAC header to determine whether a response frame needs to be sent. If a response frame needs to be sent, the lower MAC processing units 36 and 38 generate an appropriate response frame and send it via the corresponding physical processing units 32 and 34. In addition, when the RA field is a broadcast address, if it is a frame within the same BSS, the Frame Body is extracted from the MAC frame. Whether it is a frame within the same BSS is confirmed based on the address field in which the BSS Identifier (BSS identifier) ​​(hereinafter referred to as BSSID) which is the MAC address of the AP is recorded. In the MAC frame sent from the AP, TA represents the BSSID. When the RA field is a multicast address, if the frame is within the same BSS and the multicast address contains the MAC address of the wireless link, the Frame Body is extracted from the MAC frame. Broadcast addresses and multicast addresses are also collectively referred to as group addresses. When the group address is handled as MLD, the MAC address of the AP MLD may be used instead of the BSSID.

[0096] The response frame is a control frame, including an Ack frame (acknowledgement frame) and a Block Ack frame. In the control frame, RA must exist, but TA may not exist. In the case of a response frame, when the RA field is the MAC address of the wireless link, the lower MAC processing unit 36, 38 further processes the response frame, and if the Frame Body exists, it extracts it. In addition, when the RA field of the response frame is a broadcast address or the RA field is a multicast address and contains the MAC address of the wireless link, if the MAC address of the receiving object is set in the TA, the lower MAC processing unit 36, 38 further processes the response frame, and if the Frame Body exists, it extracts it. The lower MAC processing unit 36, 38 delivers the Frame Body to the upper MAC processing unit 40 together with the sequence number extracted from the MAC header, TA, the flow identifier if it is a QoS data frame, and the final address of the data (Destination Address; hereinafter referred to as DA) if it exists when the device is the AP MLD described later.

[0097] The upper MAC processing unit 40 determines the MAC address of the upper MAC processing unit 40 or the representative MAC address of the wireless communication device of the transmission source associated with the TA, and rearranges the FrameBody in the order of the sequence number according to each traffic identifier. That is, the upper MAC processing unit 40 has a reordering buffer. In the case of a data frame, if the final transmission target is the wireless communication device, the upper MAC processing unit 40 delivers the Frame Body to the upper layer. When the AP MLD22 receives a data frame, it performs a forwarding process if the DA is not the wireless communication device of the present wireless communication device. As a means of deriving the MAC address of the upper MAC processing unit 40 or the representative MAC address of the wireless communication device of the transmission source of the data from the TA, there is a method of knowing in advance through negotiation between wireless communication devices which MAC address of the wireless link is used under which upper MAC processing unit 40 address or representative address. There is also a method of notifying each other of their address relationship in the process of establishing communication through any wireless link. Furthermore, the regularity in assigning the MAC address or representative address of the upper MAC processing unit 40 and the MAC address of each wireless link may be set in advance, and the MAC address or representative address of the upper MAC processing unit 40 may be derived based on the regularity.

[0098] There is a method as follows: between wireless communication devices performing multi-link communication, in a relationship where one wireless communication device becomes an AP MLD in each wireless link and the other wireless communication device becomes a STA MLD in each wireless link, any one of the multiple wireless links performing multi-link communication is set as a primary link or a main link (primary link), and the remaining wireless links are set as secondary links or secondary links (secondary link). The number of secondary links or secondary links may be 1. In the first embodiment, the primary link is set as AP MLD. The link is related to the frequency, so the primary link is also called the primary frequency or the main frequency, and the secondary link can also be called the secondary frequency or the secondary frequency.

[0099] In this method, STA MLD observes the status of the wireless medium of the main link, obtains access to the main link when the main link is empty, and obtains access to the secondary link when the secondary link is also empty, and transmits in the secondary link simultaneously with the main link.

[0100] When AP MLD sends a signal to STA MLD, it obtains access rights based on the main link as STA MLD does, and sends a signal to STA MLD in the main link. When STA MLD communicates in the main link, when APMLD sends to STA MLD in the sub-link of the STA MLD, interference occurs between the main link and the sub-link in the STA MLD.

[0101] Therefore, in this method, when interference occurs between links, the AP MLD should not transmit to the STA MLD in the secondary link of the STA MLD.

[0102] However, depending on the wireless communication device, there are mixed cases where interference between wireless links becomes a problem and cases where it does not become a problem. When interference between wireless links does not become a problem, when multi-link communication is performed between wireless communication devices, each link can be sent independently. Therefore, it is not necessary to perform multi-link communication based on the main link, such as obtaining access rights by observing the state of the wireless medium, and when the sub-link is also empty at the same time, sending in the sub-link at the same time as the main link.

[0103] In the above-described multilink communication based on the main link, when transmission can be performed in the sublink but not in the main link, control is performed so that transmission in the sublink is not performed, so the transmission opportunities of the wireless communication device are reduced.

[0104] The transmission of data frames from the AP MLD to the STA MLD is limited to the case where the data frames are transmitted only in the main link based on the main link or in the case where the data frames are transmitted in both the main link and the sub-link when the sub-link is also empty at the same time. However, if the STA MLD does not perform the transmission, it is technically possible to perform the transmission of data frames to the STA MLD only in the sub-link.

[0105] However, the above method does not consider a method of transmitting data frames only in the secondary link, which would result in a decrease in the transmission opportunities of the APMLD.

[0106] Furthermore, in this method, when the STA MLD transmits data frames only in the primary link, the AP MLD considers that it should not transmit data frames to the STA MLD in the secondary link in consideration of interference between links.

[0107] In actual communication, the STA MLD on the receiving side of the data frame may send a response frame. In such a case, the transmission to the STA MLD should not be performed in the secondary link. However, this countermeasure is not studied.

[0108] Therefore, in this embodiment, the AP MLD transmits without causing interference in the wireless links where interference is a problem in each STA MLD. In this embodiment, the wireless links are shared among the STA MLDs where no interference occurs between the wireless links. In this embodiment, even when the main links are different due to different STA MLDs, complex control is prevented.

[0109] 《non-STR MLD, non-STR link》

[0110] Depending on how a wireless communication device that performs multi-link communication is implemented, constraints may occur between wireless links.

[0111] In order to actually transmit the signal from the physical processing unit 32, 34 to the wireless medium via the antenna, it will pass through the analog processing unit (not shown). The analog processing unit converts the PHY packet, which is a digital signal, into an analog signal of a frequency corresponding to the wireless link, and sends it from the antenna. When receiving, the analog processing unit converts the analog signal received by the antenna into a digital signal so that it can be processed by the physical processing unit 32, 34. Consider sharing the RF filter used by the analog processing unit across multiple physical processing units 32, 34. The RF filter is a filter that only allows signals in a certain frequency range to pass, and when shared across multiple physical processing units 32, 34, it has a frequency range with a width that includes the frequencies of multiple wireless links corresponding to the multiple physical processing units 32, 34.

[0112] For example, in Figure 1In the case where the analog processing unit of Link2 and the analog processing unit of Link3 share an RF filter, when a signal is transmitted in Link2, the transmitted signal leaks to Link3, causing interference in the reception of Link3. In such a situation, even if a PHY packet storing a frame with the MAC address of Link3 as RA (or even with the wireless communication device as the transmission target) is received in Link3, a situation may occur where it cannot be correctly received and decoded. For example, in a wireless LAN that complies with IEEE802.11, a minimum receiving sensitivity required by each MCS is specified, but sometimes a PHY packet cannot be decoded even if a receiving power above the corresponding minimum receiving sensitivity is used to receive the PHY packet. In addition to this, there is a situation where the PHY packet cannot be decoded even if the adjacent channel rejection level is met. That is, even if the required specifications related to the reception of normal PHY packets are met, reception and decoding cannot be performed.

[0113] Depending on the installation method, sometimes the frequency range used by each wireless link is limited in the digital filter in the physical processing unit 32, 34, and a local oscillator (Local Oscillator; hereinafter referred to as LO) is provided for each wireless link, so if the PHY packet uses a low multi-value modulation such as binary phase shift keying (Binary Phase Shift Keying; hereinafter referred to as BPSK), it can be decoded.

[0114] However, if only a single link is operated, even if the same conditions such as reception power and MCS can be received and decoded without collision of wireless signals, when sending in one of the two wireless links, at least the MAC frame addressed to the wireless communication device may not be received in the other link. When sending in one link cannot be simultaneously received in the other link, that is, two wireless links that cannot send and receive simultaneously in parallel are said to be in a non-simultaneous transmission and reception (hereinafter referred to as non-STR) link relationship.

[0115] Furthermore, the non-STR link can be said to be a wireless link whose reception is restricted due to transmission in some other wireless link or a wireless link that cannot transmit or receive independently of some other wireless link.

[0116] Depending on the implementation method, there are cases where, in two wireless links that are non-STR links, when transmission is being performed in one link, carrier sense cannot be performed in the other link.

[0117] Will Figure 1When the RF filter of the analog processing unit of Link1 is separated from the RF filters of the analog processing units of Link2 and Link3, the transmission and reception of Link1 is not affected by the transmission and reception of Link2 and Link3, and the transmission and reception of Link1 can be performed independently of the transmission and reception of Link2 and Link3. In this case, the required specifications related to the reception of PHY packets can be met and the PHY packets can be received and decoded normally, and the waiting action that meets the carrier sense regulations can be performed. In the following description, two wireless links that can transmit and receive simultaneously and in parallel are referred to as being in a simultaneous transmission and reception (hereinafter referred to as STR) link relationship.

[0118] In addition, the STR link can be said to be a wireless link whose reception is not restricted by the transmission in some other wireless link or a wireless link that can transmit and receive independently of some other wireless link.

[0119] If the relationship between two wireless links cannot achieve STR, the wireless links are in a non-STR relationship. If the wireless links do not have a non-STR relationship, the wireless links are in a STR relationship. STR relationships and non-STR relationships are exclusive. Whether two wireless links are in a non-STR link relationship can also be said to depend on the frequency separation distance of the two wireless links.

[0120] For example, in Figure 1 In some cases, if the frequency difference between Link 2 and Link 3 is large enough, both of them become STR links. In this way, a wireless communication device that may generate a wireless link that becomes a non-STR link depending on the combination of wireless links is called a non-STR MLD.

[0121] In addition, non-STR MLD can communicate in more than one wireless link, but can also be set as an MLD that cannot send or receive frames in other wireless links when sending or receiving frames in one wireless link. Non-STR MLD (1) can only send or receive data frames / management frames to other MLDs in one wireless link at the same time, and (2) can wait (listen or standby) in one or more wireless links. The waiting action includes receiving the initial control message (for example, Request to Send (hereinafter referred to as RTS) / Multi-User RTS (hereinafter referred to as MU RTS)) and Clear Channel Assessment (hereinafter referred to as CCA). The reception of the initial control message can also include one or more limitations of spatial stream, MCS (data rate), PPDU type, and frame type. Link switching delay can also be indicated by non-AP MLD.

[0122] On the other hand, even in any combination of wireless links, two wireless links cannot be in a non-STR link relationship with each other, and a wireless communication device in which any link can be used as a STR link is called a STR MLD.

[0123] In addition, when the selection result of the wireless link is that all the wireless links can be used as STR links, the wireless communication device can also be called STR MLD, and when at least two wireless links are in a non-STR link relationship, the wireless communication device can also be called non-STR MLD. In the following description, unless otherwise specified, the definitions of STR MLD and non-STR MLD are set to the former. In this embodiment, whether the wireless communication device is non-STR MLD or STR MLD is the main point, compared with whether the wireless communication device is non-STR MLD or STR MLD.

[0124] In this embodiment, the AP MLD is set to be a STR MLD in which both wireless links are in a STR link relationship regardless of the combination of wireless links. On the other hand, the STA MLD is set to be a non-STR MLD and a STR MLD. A wireless communication device that is a STA MLD and a non-STR MLD is referred to as a non-STR STAMLD. A wireless communication device that is a STA MLD and a STR MLD is referred to as a STR STA MLD. Even if non-STR STA MLD and STR STA MLD are mixed in the wireless communication system, the AP MLD can perform multi-link communication with both non-STR STA MLD and STR STAMLD.

[0125] 《Setting the main link for STA MLD based on AP MLD and notifying STA MLD》

[0126] When AP MLD22 sends a beacon frame in each wireless link, it also notifies information related to the communication status of other wireless links. For example, in a wireless LAN that complies with the IEEE802.11 standard, information elements such as the Reduced Neighbor Report element can be used to notify information related to the communication status of other AP MLDs. In this embodiment, this element is also used to notify the main link.

[0127] Figure 3 An example of the format of the beacon frame transmitted by the AP MLD 22 is shown. Strictly speaking, the beacon frame is transmitted by the APMLD 22 via an arbitrary wireless link. If transmitted from Link 1, it is transmitted from the AP having the MAC address of the lower MAC processing unit 36, and if transmitted from Link 2, it is transmitted from the AP having the MAC address of the lower MAC processing unit 38. The beacon frame includes a MAC header, a Frame Body (variable length in octet units), and an FCS (4 octets).

[0128] The MAC header includes a Frame Control field (2 octets), a Duration field (2 octets), an Address1 field (6 octets), an Address2 field (6 octets), an Address3 field (6 octets), a Sequence Control field (2 octets), and a HT Control field (0 or 4 octets).

[0129] The Frame Control field includes a Type subfield and a Subtype subfield. The AP MLD records the identification information of the management frame in the Type subfield, records the identification information of the beacon in the Subtype subfield, and sends the beacon frame.

[0130] The Frame Body includes information inherent to the frame type and frame subtype. The Frame Body includes a large number of information elements.

[0131] Figure 4 An example of the format of a Reduced Neighbor Report element as an example of an information element included in the Frame Body of a beacon frame is shown. The Reduced Neighbor Report element includes an Element ID field (1 octet), a Length field (1 octet), and a Neighbor AP Information field (variable length in octet units).

[0132] The Neighbor AP Infomation field includes the Target Beacon Transmission Time (hereinafter referred to as TBTT) Information Header subfield (2 octets), the Operating Class subfield (1 octet), the Channel Number subfield (1 octet), and the TBTT Information Set subfield (variable).

[0133] In a wireless LAN that complies with the IEEE802.11 standard, the position of the center frequency on the frequency of the wireless link can be grasped by the channel number. Channel numbers are added at 5MHz intervals. The AP MLD records this value in the Channel Number subfield. The AP MLD records the information obtained in accordance with the regulations (output restrictions, etc.) of each country and region and the channel width in the Operating Class subfield.

[0134] Through these two subfields, the STA MLD can understand which frequency position and channel width the AP MLD uses to operate.

[0135] The TBTT Information Header field includes the TBTT Information FieldType subfield (2 bits), the Filtered Neighbor AP subfield (1 bit), the Reserved subfield (1 bit), the TBTT Information Count subfield (4 bits), and the TBTT Information Length subfield (8 bits). The Reserved field is currently unused and is reserved for future use.

[0136] The TBTT Information Set subfield includes a single or multiple TBTT Information subfields.

[0137] Each TBTT Information subfield includes a Neighbor AP TBTT Offset subfield (1 octet), a BSS Identifier (hereinafter referred to as BSSID) subfield (optional) (0 octets or 6 octets), a Short-SSID subfield (optional) (0 octets or 4 octets), and a BSS Parameters subfield (optional) (0 octets or 1 octet). The AP MLD records the BSSID as the identifier of the BSS in the BSSID subfield. The AP MLD records the SSID as the service set identifier of the wireless LAN system in the Short-SSID subfield. The BSSID subfield and the Short-SSID subfield are not required, and the Neighbor AP Infomation field may not include these subfields.

[0138] The BSS Paramters field includes an OCT Recommended subfield (1 bit), a Same SSID subfield (1 bit), a Multiple BSSID subfield (1 bit), a TransmittedBSSID subfield (1 bit), a Member Of ESS With 2.4 / 5GHz Co-Located AP subfield (1 bit), an Unsolicited Probe Response Active subfield (1 bit), a Co-Located AP subfield (1 bit), and a Reserved subfield (1 bit).

[0139] STA MLD receives the Figure 4 The beacon frame of the Reduced Neighbor Report element shown can determine which frequency position and channel width the surrounding APs (including the same device) use to operate, but cannot determine which AP is involved in multi-link operations under the same AP MLD as the AP that sends the beacon frame.

[0140] The Reduced Neighbor Report element can additionally include an information field. Therefore, the APMLD of this embodiment can notify the STA MLD of this information by adding information indicating whether the AP notified by the Reduced Neighbor Report element is used under the same AP MLD and information indicating whether the wireless link sending the beacon frame is the main link to the information field.

[0141] In addition, the AP MLD may allocate a link identifier (Link Identifier; hereinafter referred to as Link ID) to each wireless link, and the link identifier may also be recorded in the information field.

[0142] Figure 5 An example of the format of the Reduced Neighbor Report element with this information field added is shown in FIG. Figure 5 Not shown, but the TBTT Information Header field includes Figure 4 The same subfields, TBTTInformation Set field includes Figure 4 Same subfield.

[0143] Neighbor AP Information field and Figure 4 Similarly, it includes the TBTT Information Header subfield, the Operating Class subfield, the Channel Number subfield, and the TBTT Information Set subfield, and also includes the MLO subfield (1 octet).

[0144] The MLO subfield is an information field used to notify the STA MLD of information used for multi-link communication. It is added when the AP notified using the Reduced Neighbor Report element is used under the same AP MLD. The MLO field includes the Primary Link subfield (1 bit), the Link ID subfield (3 bits), and the Reserved subfield (4 bits).

[0145] The AP MLD records information indicating whether the wireless link used by the AP notified by the Reduced Neighbor Report element is the primary link in the Primary Link subfield. The AP MLD records the link identifier of the wireless link used by the AP in the Link ID subfield. In the case where the wireless link used by the sent beacon frame is itself the primary link, in order to notify the primary link, information related to the AP itself that sent the beacon frame should also be included in the Reduced Neighbor Report element.

[0146] The size of the Primary Link field is sufficient as 1 bit. When the wireless link used by the AP is the primary link, set "1" in the Primary Link subfield. When it is not the primary link, set "0" in the Primary Link subfield. If the maximum number of wireless links that the AP MLD can correspond to is limited, the number of bits of the Link ID subfield can be limited. For example, if the maximum number of wireless links is limited to 8 and the link identifier is assigned from 0, the size of the Link ID subfield is 3 bits. If it is set that the link identifier is not used for a special meaning (set to Reserved), the maximum number of links is 7 under 3 bits. When Figure 5 When the size of the MLO subfield is set to 1 octet, if the Primary Link field is set to 1 bit and the Link ID field is set to 3 bits, the remaining 4 bits can be left for future use (set to Reserved).

[0147] Next, the second and third examples of the method for notifying information for multi-link communication are described. Figure 5A new information field such as the MLO field shown is added to the Reduced Neighbor Report element. In the second and third examples, no new information field is added, but the Reserved bit in the existing Reduced Neighbor Report element is used to report information for multi-link communication.

[0148] like Figure 4 As shown, the TBTT Information Header field in the Reduced Neighbor Report element includes a Reserved bit (B3). Figure 6 An example of the format of the Reduced Neighbor Report element in the second example of notifying information for multilink communication using the bit B3 is shown.

[0149] In the second example, the AP MLD records the Multi-Link (hereinafter referred to as ML) information that can identify the situation that the AP notified by the Reduced Neighbor Report element performs multi-link operation under the same AP MLD in bit B3 of the TBTT Information Header field. The AP MLD sets the ML bit to "1" when the AP is used under the same AP MLD, and sets the ML bit to "0" when the multi-link operation is not performed under the same AP MLD.

[0150] If the ML bit of the Reduced Neighbor Report element is "1", the STA MLD that receives the beacon frame including the ML bit uses the wireless link notified by the Reduced Neighbor Report element as a candidate for the wireless link used in the multi-link operation with the AP MLD that transmits the beacon frame.

[0151] In addition, if Figure 4 As shown, the BSS Parameters subfield in the TBTT Information field in the Reduced Neighbor Report element also includes a Reserved subfield (bit B7). Figure 7 An example of the format of the Reduced Neighbor Report element in the third example of notifying information for multilink communication using the bit B7 is shown.

[0152] The AP MLD records the same ML information as in the second example in bit B7 of the BSS Parameters field. Figure 7The setting method of the ML subfield in Figure 6 The ML subfield in . Alternatively, you can use Figure 6 ML subfield, and replace Figure 7 , the last bit B7 of the BSS Parameters field is used to indicate whether it is the primary link. If this is done, it is possible to notify which wireless link is operating as the primary link. This bit B7 is used together with Figure 5 The Primary Link subfield of the

[0153] In this way, Figure 6 , Figure 7 In the example, the AP MLD uses the ML bit to notify the STA MLD whether the AP notified by the Reduced Neighbor Report element is performing multi-link actions under the same AP MLD. Figure 6 , Figure 7 In the example, you can also append the same Figure 5 The MLO subfield is also a 1-octet field, which is used to inform the AP whether the MLD sets the wireless link that sends the beacon frame as the main link. Figure 5 The MLO subfield of the Reduced Neighbor Report element, when present, indicates that the AP notified using the Reduced Neighbor Report element is used under the same AP MLD, so it exists instead of Figure 6 , Figure 7 On the other hand, Figure 6 , Figure 7 In the case of the example, when the MLO subfield is further added, the ML field notifies whether the AP notified by the Reduced Neighbor Report element is used under the same AP MLD. When the ML subfield is set to "1" and the AP notified by the Reduced NeighborReport element performs multi-link operation under the same AP MLD, the MLO subfield exists. In this way, the combination of the MLO subfield and the ML subfield is a multi-stage notification means for additionally notifying the main link information and Link ID information.

[0154] Next, a fourth example in which the AP MLD notifies the STA MLD of information related to the main link will be described.

[0155] The size of the TBTT Information subfield within the Reduced Neighbor Report element is variable. The size of the TBTT Information subfield is determined by the value of the TBTT Information Length subfield. Then, the type of subfields contained in the TBTT Information subfield is determined based on the size of the TBTT Information subfield specified by the TBTT Information Length subfield.

[0156] Figure 8 This is a table showing an example of the relationship between the value of the TBTT Information Length subfield and the types of subfields included in the TBTTInformation subfield under the wireless LAN standard. For example, when the value of the TBTTInformation Length subfield is 1, it means that the TBTT Information subfield only includes the Neighbor AP TBTT Offset subfield. When the value of the TBTT Information Length subfield is 2, it means that the TBTT Information subfield includes the Neighbor AP TBTT Offset subfield and the BSS parameters subfield. When the value of the TBTT Information Length subfield is 5, it means that the TBTT Information subfield includes the Neighbor AP TBTT Offset subfield and the Short-SSID subfield. Below, similarly, when the value of the TBTTInformation Length subfield is 12, it means that the TBTT Information subfield includes the Neighbor AP TBTT Offset subfield, the BSSID subfield, the Short-SSID subfield, and the BBSparameters.

[0157] In the value of the TBTT Information Length subfield, there is a (Reserved) value that is not currently used. If the size of the new subfield contained in the TBTTInformation field is defined in such a way that the value of the TBTT Information Length subfield becomes the arbitrary Reserved value, a new subfield can be set in the TBTT Information field. The AP MLD may also use this subfield to notify whether the AP notified by the Reduced Neighbor Report element is used under the same AP MLD and whether the wireless link of the AP is the main link.

[0158] Alternatively, AP MLD may record in this subfield information that can identify whether the AP is being used under the same AP MLD and a link identifier in the multi-link action of the AP's wireless link, and AP MLD may use other information elements to notify the link identifier of the wireless link set as the main link.

[0159] The link identifier may also be, for example, Figure 1 , Figure 2 An example corresponding to X depicted as LinkX. Fig. 9 An example of the format of the Reduced Neighbor Report element is shown, in which the ML Link ID subfield (1 octet) is newly defined after the BSS Parameters subfield in the TBTT Information field. The AP MLD records the link identifier of the AP's wireless link notified by the Reduced Neighbor Report element in the ML LinkID subfield.

[0160] When the ML Link ID subfield is included in the TBTT Information field, the BSSID subfield, Short-SSID subfield, and BSS Parameters subfield are also necessarily included in the TBTT Information field. In this case, 13 may be set as the value of the TBTT Information Length subfield.

[0161] If a rule is set that each wireless link used in multi-link communication must have the same SSID, the ML Link ID subfield, BSSID subfield, and BSS Parameters subfield must be included in the TBTTInformation field as a group. In this case, 9 can be set as the value of the TBTT Information Length subfield.

[0162] In one example of the wireless LAN standard, Figure 8 As shown, the values ​​13 and 9 of the TBTT Information Length subfield are not used. If the values ​​13 and 9 are already used in the TBTT Information Length subfield for other purposes, the length of the ML Link ID subfield may be adjusted to an arbitrary value of Reserved.

[0163] In addition, here, the expression "main link" is used, but it can also be called an anchor link instead.

[0164] AP MLD can use the ML Link ID subfield with Figure 5 The MLO subfield shown similarly notifies the STA MLD of the wireless link set as the main link.

[0165] For example, AP MLD is set as Figure 1 Such three wireless links use the beacon frame transmitted in Link1 to notify Link2 and Link3 that they can be used in multi-link communication and that Link2 is the main link.

[0166] AP MLD uses the beacon frame sent in Link2 to notify Link1 and Link3 that they can be used in multi-link communication and that Link2 is the main link. In this case, Link2 sends a beacon frame, so if the information of Link2 itself cannot be set using the Reduced Neighbor Report element, it cannot be notified that Link2 is the main link. In this case, AP MLD can use other information elements to notify that Link2 is the main link. Furthermore, AP MLD can also notify the identifier of the wireless link itself that sends the beacon frame.

[0167] The AP MLD transmits a beacon frame in Link3 to notify Link1 and Link2 that they can be used in multi-link communication and that Link2 is the main link.

[0168] In addition, in the above description, it is explained that this information is notified to the STA MLD using the information elements in the beacon frame, but it can also be notified to the STA MLD using the information elements in the probe response frame. The probe response frame is a management frame in which the AP MLD sends function information, supported data rates, etc. to the STA MLD in response to the probe request frame sent by the STA MLD. Referring to the case of the beacon frame, the information elements related to MLO can be added to the probe response frame.

[0169] In addition, the same information may be notified using other management frames such as action frames. In this case, referring to the case of the beacon frame, the information element related to MLO may be added to the action frame.

[0170] In addition to the information shown above, the above information elements or new information elements may also be used for notification. The MAC address (6 octets) of the AP MLD is necessary for the sequence number processing in the STA MLD as mentioned above, so it is necessary to use certain information elements contained in frames such as beacons to notify the MAC address of the AP MLD to the STA MLD.

[0171] 《Notification of non-STR / STR link from STA MLD to AP MLD》

[0172] AP MLD notifies STA MLD of the information as described above, so that if STA MLD receives the above information from AP MLD using any wireless link before connecting to AP MLD using any wireless link, it can understand which other wireless link in AP MLD can be used for multi-link communication. In addition, STA MLD can determine which pair of wireless links among the wireless links that can perform multi-link communication with AP MLD is in a non-STR link relationship in the STA MLD (or which wireless link is a non-STR link) or whether all pairs of wireless links that can perform multi-link communication with AP MLD are in a STR link relationship in the STA MLD (all wireless links are in a STR link relationship with each other) before connecting to AP MLD using any wireless link.

[0173] For example, similar to the AP MLD, the STA MLD also wants to perform multi-link communication using Link 1, Link 2, and Link 3. Fig.10 An example of three wireless links is shown in which Link2 and Link3 are in a non-STR link relationship, and Link1 and the other two wireless links Link2 and Link3 are in a STR link relationship.

[0174] In such Fig.10 In such a state, when the STA MLD establishes communication with the AP MLD, it notifies at least one AP in the AP MLD of the relationship between the non-STR links and the STR links between the wireless links that want to perform multi-link communication. In this case, the AP MLD may or may not notify the link identifier.

[0175] Each BSSID, that is, the MAC address of each AP in the AP MLD, corresponds to each wireless link on a one-to-one basis. Therefore, if the STAMLD is not notified of the link identifier by the AP MLD, it can use the BSSID, or in other words, the MAC address of the AP in the AP MLD, instead of the link identifier.

[0176] The following describes an example in which the STA MLD notifies the AP MLD of the relationship between non-STR links and the relationship between STR links between wireless links when the AP MLD notifies each link identifier. This example is an example in which the STA MLD notifies the AP MLD of the relationship between links in Link1.

[0177] The AP MLD has a MAC address of AP1 in Link1, a MAC address of AP2 in Link2, and a MAC address of AP3 in Link3. The STA MLD has a MAC address of STA1 in Link1, a MAC address of STA2 in Link2, and a MAC address of STA3 in Link3.

[0178] First, STA MLD connects to AP MLD via Link1. At this time, STA with MAC address STA1 receives a packet sent by AP with MAC address AP1. Figures 5 to 9 The STA with MAC address STA1 also knows that AP MLD uses the MAC address of AP2 in Link2 and the MAC address of AP3 in Link3. On this basis, the STA with MAC address STA1 sends an association request frame to the AP with MAC address AP1 in Link1, and tries to connect to the AP with MAC address AP1.

[0179] The association request frame is a type of management frame sent from the STA MLD to the AP MLD, and includes the data rate supported by the STA MLD, the SSID of the network to which the STA MLD wishes to connect, and the like.

[0180] Association request frame with Figure 3 The beacon frame of the MAC header includes a MAC header, a Frame Body, and an FCS. The Type subfield of the Frame Control field included in the MAC header records the identification information of the management frame, and the Subtype subfield records the identification information of the association request.

[0181] The STA with MAC address STA1 uses the information element in the Frame Body of the association request frame to notify the AP with MAC address AP1 of other link information (Link Information) that can be used in the STA MLD. The STA with MAC address STA1 can also notify the information using, for example, an information element defined as a Multi-Link (ML) element. The STA with MAC address STA1 can also notify by setting it in other information elements added as an extension standard of the wireless LAN, such as the Extremely High Throughput (hereinafter referred to as EHT) Capabilities element.

[0182] Here, the case where the notification is performed using the ML element defined as one of the information elements in the Frame Body of the association request frame is described as an example. However, even if the type of information element changes, the notification method on the STA MLD side and the method of obtaining the information on the AP MLD side basically do not change. Therefore, even if the ML element is not used and the EHT Capabilities element is used, the same processing as the processing described below is performed.

[0183] Furthermore, when the STA MLD transfers the connection from a certain AP MLD to another AP MLD, if these AP MLDs constitute the same Extended Service Set (hereinafter referred to as ESS), the STA MLD can use a reassociation process with the transfer destination AP MLD. ESS refers to a plurality of BSSs connected to each other that can be handled as a single BSS at the Logical Link Control (hereinafter referred to as LLC) layer within the data link layer of the OSI reference model.

[0184] During the reassociation process, the reassociation request frame sent by the STA MLD to the AP MLD can also be notified in the same way as the above-mentioned association request frame. The reassociation request frame is also a type of management frame. The basic structure of the reassociation request frame is similar to Figure 3The reassociation request frame is the same as the beacon frame shown. The difference between the reassociation request frame and the beacon frame is the information elements contained in the Subtype and Frame Body. The subtype of the reassociation request frame is reassociation request.

[0185] In the ML element in the association request frame sent by STA1, STA MLD notifies AP MLD of the fact that Link2 and Link3 can be set by AP MLD and whether Link2 and Link3 are in a non-STR link relationship with other links. In addition, if they are not in a non-STR link relationship, they are in a STR link relationship, so whether they are in a non-STR link relationship is also called whether they are in a STR link relationship.

[0186] exist Fig.10 In the example, the STA MLD notifies the AP MLD that Link2 is in a STR link relationship with Link1 and in a non-STR link relationship with Link3, and that Link3 is in a STR link relationship with Link1 and in a non-STR link relationship with Link2.

[0187] The STA MLD selects all or a partial set of the multiple wireless links notified from the AP MLD, and notifies the AP MLD of the selected wireless links as wireless links to be used. In addition, when making this selection, the STA MLD may select other wireless links that become non-STR link pairs for the wireless link designated as the main link, but in order to avoid the following Fig.18B In the case where it is possible to determine whether the two links are non-STR or STR based on the difference in the frequency separation distance between the links, if the difference in the frequency separation distance between the links is within the threshold, the STA MLD determines that the two links are in a non-STR link relationship. In the case where the STA MLD has an information management database that stores wireless links in a STR relationship, the MAC processing layer can also access the information management database, extract information, and determine whether the two wireless links are in a STR link relationship.

[0188] Fig.11 An example of the format of the ML element included in the Frame Body of the association request frame is shown. STA MLD can be used Fig.11 The ML element shown notifies the AP MLD of information related to non-STR links and information related to STR links.

[0189] The basic structure of the association request frame is Figure 3The association request frame is the same as the beacon frame shown. The difference between the association request frame and the beacon frame is the Subtype field and the information elements contained in the Frame Body. The Subtype of the beacon frame is beacon, but the Subtype of the association request frame is association request. The Frame Body of the association request frame can also contain a large number of information elements. Fig.11 An example of the format of the ML element is shown as an example of the information element included in the Frame Body of the association request frame.

[0190] The ML element includes an Element ID field (1 octet), a Length field (1 octet), an Element ID Extension field (1 octet), a STA MLD field (6 octets), a Number Of Link Information Sets field (1 octet), and a Link Information Set field (variable length in octets).

[0191] Fig.11 The ML elements in Figure 4 The Reduced Neighbor Report element is different in that an Element ID Extension field is newly added after the Length field. This is because the number of Element IDs used to identify information elements in the wireless LAN standard that complies with the 802.11 standard has reached the upper limit of the number that can be expressed in 1 octet, so it is impossible to directly define a new ML element using only the Element ID. Only when the Element ID takes the maximum value of "255", the Element ID Extension field is added, and the additional value used to identify the information element is recorded in this field.

[0192] The Element ID Extension field also has 1 octet, and in the wireless LAN standard conforming to the existing 802.11 standard, a value of "0" in this field is reserved, and a value of "1" or higher is assigned to identify the information element, similarly to the Element ID. Here, a unique value for identifying the ML element is recorded.

[0193] exist Fig.11 In the ML element, the STA MLD field is configured after the Element ID Extension field. The STAMLD field notifies the MAC address of the STA MLD.

[0194] After the STA MLD field, the Number Of Link Information Sets field is configured. The Number Of Link Information Sets field informs the number of Link Information subfields constituting the Link Information Set field.

[0195] After the Number Of Link Information Sets field, the Link Information Set field is configured. The Link Information Set field includes a single or multiple Link Information subfields (each 3 octets).

[0196] The Link Information subfield includes a Link ID subfield (1 octet), a Non-STR Link 1 subfield (1 octet), and a Non-STR Link 2 subfield (1 octet). The Link ID subfield notifies the link identifiers of the wireless links other than the wireless link that transmits the ML element. The Non-STR Link 1 subfield notifies the link identifiers of the other first wireless links that are in a non-STR link relationship with the wireless link with the link identifier notified by the Link ID subfield. The Non-STR Link 2 subfield notifies the link identifiers of the other second wireless links that are in a non-STR link relationship with the wireless link with the link identifier notified by the Link ID subfield. Wireless links other than the wireless links notified of being non-STR links have an STR link relationship with respect to the wireless link with the link identifier notified by the Link ID subfield.

[0197] When the status of the wireless link in the AP MLD is Fig.10In the state shown, when STA MLD sends MLElement (ML element) from STA1, it records the link identifier of Link2 in the Link ID subfield of the first Link Information field. The other first wireless link that is in a non-STR link relationship with Link2 is Link3, so STA MLD records the link identifier of Link3 in the Non-STR Link 1 subfield. The link identifiers of Link2 and Link3 are, for example, "2" and "3", respectively. The only wireless link that is in a non-STR link relationship with Link2 is Link3, so STA MLD records information indicating Not Available (hereinafter referred to as N / A) in the non-STRLink 2 subfield. The information indicating N / A is, for example, "0". If a number starting from 0 is assigned to the link identifier of the wireless link, the maximum value of the subfield, that is, "255", can also be set to information that can identify a situation such as N / A.

[0198] When STA1 sends an ML Element, STA MLD records the link identifier of Link3 in the Link ID subfield of the second Link Information field. The only wireless link that is a non-STR link with Link3 is Link2, so STA MLD records the link identifier of Link2 in the Non-STR Link 1 subfield and records information indicating N / A in the non-STR Link 2 subfield.

[0199] In addition, since the fact that Link3 and Link2 are in a non-STR link relationship has been notified in the first LinkInformation field, the STA MLD may omit this notification in the second Link Information field and record information indicating N / A in the Non-STR Link 1 subfield and the Non-STR Link 2 subfield.

[0200] In this example, the STA MLD notifies the non-STR / STR link relationship of Link2 first, and then notifies the non-STR / STR link relationship of Link3 in the order of link identifiers from small to large. However, the Link Information field includes the Link ID subfield, so the STA MLD does not necessarily need to notify in the order of link identifiers from small to large or from large to small. However, when the rule is set to notify in the ascending and descending order of link identifiers, it is convenient to manage the information of wireless links in installation.

[0201] Fig.12 Another example of the state of three wireless links is shown. Here, in addition to Link2 and Link3 being in a non-STR link relationship, Link2 and Link1 are also in a non-STR link relationship.

[0202] The status of the wireless link is as follows Fig.12 In such a state, when STA MLD sends the ML element from STA1, Fig.11 The Link ID subfield of the first Link Information subfield of the ML element shown records the link identifier of Link2, the Non-STR Link 1 subfield records the link identifier of Link1, and the Non-STR Link 2 subfield records the link identifier of Link3.

[0203] STA MLD sends an association request frame containing the ML element in Link1. In the above notification method, it is not explicitly or directly notified whether Link1 and other wireless links are in a non-STR link relationship. However, if STAMLD notifies AP MLD whether other wireless links and Link1 are in a non-STR link relationship, AP MLD can grasp whether other wireless links and Link1 are in a STR link relationship or a non-STR link relationship based on the symmetry of the notification.

[0204] As another method of notifying that two wireless links are in a STR link relationship or a non-STR link relationship, a link for notifying the sending of ML elements (in Fig.10 , Fig.12 In the example, it is a field indicating whether Link1) and other wireless links are in a STR link or non-STR link relationship. Fig.13 An example of the format of the ML element with the notification field appended is shown. The Link Information field contains multiple pairs of Link ID subfields (3 bits) and STR / Non-STR Flag subfields (1 bit). If the Link Information field is limited to 1 octet, for example, the Link Information field contains a maximum of two pairs of Link ID subfields (3 bits) and STR / Non-STR Flag subfields (1 bit).

[0205] The following describes a method of notifying that the remaining fields contain no information when generating a Link Information field in which only one pair of a Link ID subfield (3 bits) and an STR / Non-STR Flag subfield (1 bit) is provided.

[0206] When the value assigned as the link identifier of the wireless link is set to 1 or more and 0 is set to Reserved, if 0 is set in the Link ID subfield, AP MLD can determine that the subsequent subfields including this subfield do not contain information, and AP MLD does not need to process the remaining subfields. The same is true when the link identifier of the wireless link is set to the range of 0 to 6 and 7 is set to Reserved.

[0207] Alternatively, you can Fig.14 As shown, in place of Fig.13 The Link Information field is limited to 1 octet, and only one pair of Link ID subfield (3 bits) and STR / non-STR Flag subfield (1 bit) is set. In addition, here, the Link ID subfield is set to 3 bits, but it can be longer in a way to fully express the identifier of the required wireless link. The remaining area in 1 octet is called Reserve. Furthermore, if the last bit B7 is set to the More subfield indicating whether there is the next Link Information field, there is no need for the following Fig.13 When the More subfield is set to 1 bit, such as Fig.14 That way, the Reserved field becomes 3 bits.

[0208] STA MLD will send the wireless link other than the wireless link of the ML element (in this case, Link1) (in Fig.10 , Fig.12In the example, the link identifiers of Link2 and Link3) are recorded in the Link ID subfield. The STA MLD sets the flag information indicating whether the wireless link that sends the ML element and the wireless link of the link identifier recorded in the Link ID subfield are in a STR link relationship or a non-STR link relationship in the STR / Non-STR Flag subfield. When Link1 and the wireless link of the link identifier recorded in the Link ID subfield are in a STR link relationship, the STA MLD sets the flag information to "1", and when Link1 and the wireless link of the link identifier recorded in the Link ID subfield are in a non-STR link relationship, the flag information is set to "0". The STR / Non-STR Flag subfield can also be set to the STRFlag subfield. Alternatively, when Link1 and the wireless link of the link identifier recorded in the Link ID subfield are in a non-STR relationship, the flag information is set to "1", and when Link1 and the wireless link of the link identifier recorded in the Link ID subfield are in a STR link relationship, the flag information can also be set to "0". In this case, instead of using the STR / Non-STR Flag subfield, the subfield name may be Non-STR / STR Flag subfield or Non-STR Flag subfield.

[0209] If there are other wireless links that are not in a non-STR link relationship with Link1, the STA MLD may also notify the non-STR link relationship of the other wireless links. In this case, it is necessary to explicitly indicate the link identifier of the wireless link of the comparison source. Therefore, for example, Fig.15 As shown, instead of Fig.13 The Link Information field includes the Link ID1 subfield (3 bits), the Link ID2 subfield (3 bits), the STR / Non-STR Flag subfield (1 bit), and the remaining 1 bit is set to Reserved, and the Link Information field becomes 1 octet. The Link ID1 subfield is set to the link identifier of the wireless link of the comparison source, and the Link ID2 subfield is set to the link identifier of the wireless link of the comparison. The STR / Non-STR Flag subfield is used in the same way as Fig.13 Similarly, the STR / Non-STR Flag subfield indicates whether the wireless link described in the Link ID2 subfield is in a STR link relationship or a non-STR link relationship with the wireless link described in the ID1 subfield.

[0210] Alternatively, you can Fig.16 As shown, instead of Fig.13 The Link Information field is set to the Link ID subfield (3 bits) and the STR / Non-STR Flag Bitmap subfield (5 bits). The link identifier of the comparison source wireless link is set in the Link ID subfield, and the link identifiers of other compared wireless links are omitted. The bits of the STR / Non-STR Flag Bitmap subfield are used to indicate whether the comparison source wireless link is in a STR link relationship or a non-STR link relationship with the wireless links indicated in the Link ID order. B3 of the STR / Non-STR FlagBitmap subfields B3-B7 represents Link1, B4 represents Link2, and B5 represents Link3. For example, when Link1 is set in the Link ID subfield, in the case Fig.12 In that case, when Link2 and Link1 are in a non-STR relationship, and Link3 and Link1 are in a STR relationship, "0" indicating a non-STR relationship is set to B4, and "1" indicating a STR relationship is set to B5. When the compared wireless link is the wireless link of the comparison source, set the rules such as setting "0" to the corresponding bit and setting "0" to the bit assigned to the identifier of the non-existent wireless link (in the above example, up to Link5 can be expressed by the bitmap, but up to Link3 is used). If the STR / Non-STR Flag Bitmap subfield is set to B3-B6, leaving B7, it can be expressed up to Link4, and B7 can be assigned to the More subfield as described above, without the need for Fig.13 Such Number of Link Information Sets field (1 octet).

[0211] The AP MLD only needs to understand which two wireless link pairs among the wireless links to which the STA MLD can correspond are in a non-STR link relationship.

[0212] In this way, when the STA MLD notifies the AP MLD of the relationship between wireless links, when the AP MLD notifies the STA MLD of the link identifier using the beacon / probe response frame, the system is more efficient than when no notification is made. When the MAC address is set in the field to indicate the wireless link, 6 octets are required, but if the AP MLD notifies the link identifier in advance using the beacon / probe response frame, the length of the field indicating the wireless link can be reduced to 1 octet or less when notifying the relationship between wireless links on the STA MLD side. As a result, the information element used for notification from the STA MLD and even the frame length can be shortened.

[0213] On the other hand, when a wireless link is represented by a BSSID / MAC address, it is usually 6 octets. However, if it is limited to the situation where conditions such as AP MLD multi-link communication are met, in order to identify the AP with other APs in the same AP MLD, for example, it is also considered to extract a part of the area such as the last 1 octet and use the method of omitting the value to express it.

[0214] In the above description, STA MLD can use all the same wireless links as those that AP MLD can use, but sometimes it may not be able to correspond to all the wireless links provided by AP MLD. In this case, STA MLD uses ML elements to notify AP MLD of information related to the wireless links that can be corresponded. For example, if STA MLD cannot correspond to Link3, STA MLD does not set Link Information of Link3 to ML elements, but only sets Link Information of Link2 to ML elements that communicate in Link1. In this case, consider Fig.10 Based on the deletion of Link3 status, there is no wireless link with Link2 that has a non-STR link relationship, so if STA MLD is in accordance with Fig.11 If the notification method is used, information indicating N / A is recorded in the subfields of non-STR Link1 and Non-STR Link2 of Link2.

[0215] In addition, in addition to the situation where STA MLD cannot correspond to a certain wireless link, for example, due to installation reasons such as limiting the number of wireless links managed by STAMLD to a minimum or QoS reasons such as avoiding Dynamic Frequency Selection (hereinafter referred to as DFS) band for streaming data transmission, even if STA MLD can correspond to all wireless links notified by AP MLD, the wireless links used are sometimes limited to a part of the notified wireless links through certain algorithms.

[0216] In such a case, the STA MLD only needs to set Link Information about the restricted wireless links (those scheduled to actually exchange data) in the ML element and notify the AP MLD.

[0217] 《Constraints on non-STR link relationships》

[0218] exist Fig.11 In the ML element of , the subfields following the Link ID subfield are set to two subfields, the Non-STR Link1 subfield and the Non-STR Link2 subfield. This limits the number of wireless links that are in a non-STR link relationship with one wireless link to two.

[0219] The role of the main link

[0220] Next, the relationship between non-STR wireless links and the main link will be described.

[0221] The main link is a link for obtaining access rights (channel access) among multiple wireless links in a non-STR link relationship. When there are multiple pairs of wireless links in a non-STR link relationship, one of them becomes the main link and the other wireless links become the secondary links.

[0222] In this embodiment, AP MLD determines the main link. STA MLD notifies AP MLD of the mastery of multiple wireless links that can be used in this situation and the mastery of the main link determined by AP MLD, determines the wireless link to be used by STA MLD itself based on the mastered result, and after notifying AP MLD, performs multi-link communication with AP MLD when connection to AP MLD is allowed.

[0223] At this time, STA MLD considers the notification information from AP MLD and the non-STR / STR relationship between the wireless link that is a candidate for use by STA MLD itself and other wireless links, determines the wireless link that STA MLD itself uses, and notifies APMLD of the STR / non-STR relationship between the wireless link used by it and the wireless links.

[0224] The STA MLD determines the wireless link to be used based on the constraints on the wireless links that are non-STR links. One of the constraints is to limit the number of wireless links that are non-STR links to a certain wireless link to within an upper limit. Fig.11 The structure of the ML element of the received ML element limits the number of wireless links that are in a non-STR link relationship with a wireless link to two. Fig.11 If the STA MLD is constituted like an ML element of , the number of wireless links that are in a non-STR link relationship with a certain wireless link is limited to two. In addition, the upper limit value can be explicitly notified in advance from the AP MLD using a beacon frame, etc., or can be pre-defined according to the standard.

[0225] In order to send data frames or management frames on multi-link communication, STA MLD needs to be able to obtain access rights in at least the main link. For example, when STA MLD can obtain access rights in the main link using CSMA / CA, STA MLD, for example, only sends frames in the main link. In addition, before STA MLD performs multi-link communication settings such as sending an association request frame, channel access can be performed regardless of the main link, but in this case, it is limited to any one wireless link. In the above example, the association request frame is sent in Link1.

[0226] In the case where the STA MLD can obtain access rights in the secondary link at the same time as the main link, or in the case where the STA MLD allows a certain time difference in the start of transmission and can also transmit in the secondary link in accordance with the access right acquisition period (Transmission Opportunity; hereinafter referred to as TXOP) in the main link, the STA MLD can also be transmitted in the secondary link. In addition, there is no such restriction in an independent wireless link that is not in a non-STR link relationship with any other wireless link.

[0227] Here, the transmission of STA MLD is considered.

[0228] When the communication of the STA MLD is limited to the main link, fairness with the STA MLD communicating in other wireless links does not become a problem.

[0229] On the other hand, if the main link is capable of communication and the sub-link is also capable of communication, the STA MLD communicates simultaneously in the main link and the sub-link. In this case, when NAV (described later) is adopted as a channel access method in CSMA / CA and random backoff is performed in the sub-link, it is considered that the communication opportunities in the sub-link of the STA MLD are small.

[0230] On the other hand, when PIFS access is allowed in the sub-link as in the case of channel bonding (described later), channel access in the STA MLD where any two wireless links are in a STR link relationship is disadvantageous, and it is certainly unfair to the Overlapping BSS (hereinafter referred to as OBSS) STA.

[0231] In addition, in order to ensure that if the AP MLD confirms the communication status in the main link, the AP MLD can grasp the communication status in the STA MLD including other wireless links in a non-STR link relationship, the STA MLD can also allow a slight time difference but immediately release the access right obtained in the sub-link even if the access right is obtained in the sub-link if the access right fails to be obtained in the main link.

[0232] By doing so, before sending to the STA MLD, the AP MLD can observe the communication status of only the main link and thus understand whether the STA MLD has communicated (i.e., whether the AP MLD is a TXOP holder or a TXOP responder). Therefore, it is possible to avoid the transmission of the AP MLD interfering with the communication of the STA MLD.

[0233] The TXOP holder is the side that obtains the transmission access right, and the TXOP responder is the communication partner of the TXOP holder. The premise here is that the communication partner of the STA MLD is the AP MLD. In the infrastructure BSS including the AP, as a communication method of STA, in addition to this, there is also communication between STAs (direct link communication), but it is considered in other embodiments.

[0234] 《Example of the relationship between non-STR / STR links》

[0235] Fig.17A , Fig. 17B , Fig. 17C , Fig.18A , Fig.18B Several examples of non-STR link pairs and STR link pairs are shown.

[0236] Fig.17A The relationship of the wireless links is slightly different from the above. The main link is Link1. In the STA MLD, Link1 and Link2 are in a non-STR link relationship, and Link3 and the other two wireless links Link1 and Link2 are in a STR link relationship.

[0237] For example, the AP MLD sets one of the two wireless links with the shortest frequency separation distance as the main link. For example, if Link3 is far enough away from Link1 and Link2, the AP MLD sets Link1 or Link2 as the main link. Fig.17A In the example of , the AP MLD sets the wireless link (Link 1) at one end when three wireless links are arranged in frequency order as the main link.

[0238] Fig. 17B This shows a case where the frequency separation distances of the three wireless links are relatively close. In this case, AP MLD sets the central wireless link (Link2) as the main link when the three wireless links are arranged by frequency. The central Link2 is selected as the main link because it has the largest number of wireless links in a non-STR link relationship (the number of wireless links in a non-STR link relationship with Link2 is two).

[0239] In this case, in STA MLD, Link1 and Link2 are in a non-STR link relationship, and Link2 and Link3 are in a non-STR link relationship. On the other hand, Link1 and Link3 have a long frequency separation distance and are in a STR link relationship.

[0240] However, in the case of three wireless links, even if Fig. 17C In that case, when the central Link2 and the left and right Link1 and Link3 are in a non-STR link relationship, and the left and right Link1 and Link3 are also in a non-STR link relationship, if the central one, Link2 in the figure, is set as the main link, STA MLD can be sent based on the main link.

[0241] By observing the communication status of the main link, the AP MLD can understand whether the STA MLD is a TXOP holder or a TXOP responder.

[0242] exist Fig.17A , Fig. 17B , Fig. 17C In the example of , the case where there are three wireless links is shown, but the same is true even when there are four wireless links. Fig.18A As shown in the figure, Link1 and Link2 are in a non-STR link relationship, Link3 and Link4 are in a non-STR link relationship, and all other links are in a STR link relationship. In this case, non-STR link group 1 of Link1 and Link2 and non-STR link group 2 of Link3 and Link4 are handled independently, so when one of the two links constituting each link group is set as the main link, if the AP MLD observes the communication status of the main link, it can grasp whether the STA MLD is the TXOP holder or the TXOP responder.

[0243] The number of links constituting a link group does not need to be limited to two, and may be three or more. Fig.17A , Fig. 17B , Fig. 17C As shown, the same is true when three wireless links in a non-STR link relationship can independently form a link group. AP MLD can set any one of the independent link groups consisting of more than three wireless links as the main link. AP MLD pre-envisions the wireless links that may become the wireless link group based on the separation distance between the frequencies of each wireless link, and sets a main link among the wireless links envisioned as the wireless link group.

[0244] On the other hand, suppose Fig.18B In this way, the two wireless links Link2 and Link3 that are in a non-STR link relationship with each other are further set as Link1 and Link4, which are different from each other in a non-STR link relationship. For example, assuming that Link2 is set as the main link, the STA MLD uses all four wireless links Link1 to Link4 between the STA MLD and the AP MLD.

[0245] In this case, Link4 and Link2 are in a STR link relationship, so if the aforementioned main link rule is followed, Link4 should be able to be transmitted independently without regard to Link2. However, Link4 and Link3 are in a non-STR link relationship, and Link3 and Link2 are in a non-STR link relationship, so they are affected by Link2 and Link3. Therefore, when the STA MLD is about to transmit in Link4, in addition to Link3, the communication status of Link2 must also be confirmed. In addition, if the STA MLD does not do this, the following simple confirmation action cannot be performed: when the main link is set in the AP MLD, if the communication status of the STA MLD with a non-STR link relationship is confirmed only on the main link, interference with the communication of the STA MLD can be avoided.

[0246] The same problem occurs when Link 3 is set as the main link.

[0247] Therefore, in Fig.18B In this case, there is no advantage in setting the primary link. Fig.18A As shown, when link group 1 of a non-STR link pair and link group 2 of a non-STR link pair are far apart in frequency, one main link can be set for link group 1 and one main link can be set for link group 2 respectively. However, when any wireless link in link group 1 and any wireless link in link group 2 are in a non-STR link relationship, a main link cannot be set for link group 1 of a non-STR link pair and one main link cannot be set for link group 2 of a non-STR link pair respectively.

[0248] To simply solve this problem, STA MLD selects Fig.17A , Fig. 17B For example, if Link2 is set as the main link, STA MLD does not use any of Link1, Link3 or Link4. In this way, STA MLD makes the two links in the non-STR link relationship ( Fig.18B The wireless links may be selected so that each of Link2 and Link3 is not in a non-STR link relationship with other different links. In the above example, the number of other wireless links that a certain wireless link is in a non-STR link relationship is at most two.

[0249] In addition, there are other solutions as follows: Fig.18B Link 2) is a wireless link related to the STR link ( Fig.18B Link 4) About the main link ( Fig.18BLink 2) via other wireless links ( Fig.18B 2) is indirectly a non-STR link, the main link is set to a non-STR link by determining the access right. In this case, there is no need to Fig.18B The situation is excluded.

[0250] In addition, the purpose of setting the main link is to ensure the existence of communication in other wireless links that have a non-STR link relationship with respect to the main link in the STA MLD, as long as the communication status of the main link is observed in the case where the AP MLD is about to transmit in other wireless links. Therefore, if this assurance can be achieved, the conditions of the wireless links that are in a non-STR link relationship can also be relaxed.

[0251] For example, if the AP MLD can determine whether to send to the STA MLD by observing only the communication status of the main link, the condition that the number of wireless links in a non-STR link relationship is two can be relaxed to, for example, three. Fig.11 In the ML element sent by the STA MLD to the AP MLD, the number of subfields notifying the non-STR link relationship is increased from two to three. Fig.11 After the non-STR Link2 subfield shown, a non-STR Link3 subfield is added.

[0252] 《Wireless Link Selection for STA MLD》

[0253] STA MLD can also grasp the main link set by AP MLD, select a wireless link that is in a non-STR link relationship with it and can perform operations, and use ML elements to notify AP MLD of the selection result. STA MLD can also grasp the main link set by APMLD, select a wireless link that is in a STR link relationship with the main link, and use ML elements to notify AP MLD of the selection result.

[0254] "Modification of notification of non-STR / STR link relationship of STA MLD"

[0255] exist Fig.11In the ML element of , the number of non-STR Link subfields notifying the relationship between the non-STR link and the wireless link is fixed to two. However, as described previously, the information of the link in the non-STR link relationship has been notified in other links, so the notification is omitted, and there is no wireless link in the non-STR link relationship, and the non-STR Link subfield records the information indicating N / A.

[0256] Fig.19 The format of the ML element according to the first modification is shown.

[0257] The Link Information subfield includes the Link ID subfield (1 octet), the Number Of Non-STR Links (1 octet), and one or more Non-STR Link subfields (variable length in aggregate octet units) (in Fig.19 In the example, they are represented as Non-STR Link 1, ..., Non-STRLink n, each of which is 1 octet).

[0258] The Number Of Non-STR Links subfield notifies the number of links in a Non-STR link relationship. The number of Non-STR Link subfields is the value of the Number Of Non-STR Links subfield.

[0259] If this is done, for example, when the number of other wireless links that have a non-STR link relationship increases due to a situation such as 3 frames, the STA MLD sets 3 in the Number Of Non-STR Links subfield and configures 3 Non-STR Link subfields after the Number Of Non-STR Links subfield, thereby being able to respond flexibly. If the number of links that are in a non-STR link relationship is 0, the STA MLD records 0 in the Number Of Non-STR Links subfield and does not configure any Non-STR Link subfield.

[0260] The second modification example of efficiency improvement is described. Assume that the STA MLD uses Link1, Link2, and Link3 in the same way as the AP MLD, and that none of the links are in a non-STR link relationship, that is, all the wireless links are in a STR link relationship. In this case, the STA MLD Fig.19For example, in the Link Information field, a special value may be set to the Link ID subfield, and the Number Of Non-STR Links subfield and the Non-STR Link subfield may be omitted.

[0261] The third variant is described. If the number of wireless links used in multi-link communication is limited, Fig.11 as well as Fig.19 The Number Of Link Information Sets subfield of the ML element shown does not require all bits of 1 octet, and part of the bits can be used for other purposes.

[0262] For example, when the number of wireless links is limited to 8, only 3 bits of the Number Of Link Information Sets subfield are allocated to indicate the number of wireless links. If the number of wireless link groups is specified as the value of the Number Of Link Information Sets subfield + 1, 3 bits are sufficient as the length of the Number Of Link Information Sets subfield, and the remaining 5 bits can be used for other purposes. For example, if the value of the Number Of Link Information Sets subfield is 0, the number of wireless link groups is 1, if the value is 1, the number of wireless link groups is 2, and if the value is 7 (the maximum value that can be expressed by 3 bits), the number of wireless link groups is 8. Therefore, for example, 1 bit thereof can also be used as information for identifying a situation where all the wireless links used are in a STR link relationship with each other. In this case, the Non-STR Link subfield can be omitted. By doing so, the notification field length of the ML element can be shortened, achieving efficiency.

[0263] "Understanding the wireless links in the AP MLD that are related to the non-STR links of the STA MLD"

[0264] The processing of the AP MLD that receives the association request frame including the ML element as described above is basically the same as the association procedure in a wireless LAN that complies with the general 802.11 standard.

[0265] In AP MLD, the AP with MAC address AP1 delivers the information of the Frame Body of the association request frame and the MAC address STA1 of the STA to the upper MAC processing unit 40. The upper MAC processing unit 40 delivers this information to the MLME. The MLME notifies the upper MAC processing unit 40 of the instruction for generating an association response frame. The upper MAC processing unit 40 prepares the information of the Frame Body of the association response frame and the information of STA1 as the destination MAC address, and delivers them to the AP with MAC address AP1. The AP with MAC address AP1 sends the association response frame via the first physical processing unit 32.

[0266] When the AP MLD receives an association request from a STA having a MAC address STA1 and directly accepts the request, the MLME sets the Status Code field in the association response frame containing the ML element to "SUCCESS". When the AP MLD rejects the association request from the STA having the MAC address STA1, the MLME sets the Status Code field to "REFUSED" or to information indicating the reason for rejection.

[0267] In addition, a rejection reason related to multi-link communication may be newly defined. The same also applies to the transmission of the reassociation response frame during the reassociation process.

[0268] The AP MLD obtains the association request response frame containing the ML element, thereby also obtaining the MAC address of the STA MLD. Fig.11 The ML element directly notifies the STA of the MAC address of the MLD, but direct notification can be omitted.

[0269] For example, if AP MLD can obtain the MAC address of APMLD from information about certain regularities in the MAC addresses of the wireless link, then by obtaining the MAC address of STA1 or combining the MAC addresses of STA1 and other information with additional information, if the MAC address of STA MLD can be obtained, direct notification of the MAC address can be omitted.

[0270] The AP MLD can store the acquired MAC address of the STA MLD in a memory prepared in the upper MAC processing unit 40 or the MLME and accessible to the AP MLD in common.

[0271] In addition, the AP MLD also similarly holds at least the wireless links used by the STA MLDs that are in a non-STR link relationship with the main link and that are acquired by the ML element.

[0272] In AP MLD, Link2 is set as the main link. In STA MLD, Fig.10 In this way, when the AP MLD is notified that Link 3 and Link 2 (main link) are in a non-STR link relationship, the AP MLD at least holds such information and can perform the following operations.

[0273] 《Sending AP MLD considering the communication status of STA MLD》

[0274] use Fig. 20 as well as Fig.21 , which explains the action of AP MLD sending a downlink (Down Link; hereinafter referred to as DL) to STA MLD. Fig. 20 An example of two wireless links in a non-STR link relationship is shown. Here, the AP MLD notifies the STA MLD that Link1 is the main link, and the STA MLD notifies the AP MLD that Link2 and Link1 are in a non-STR link relationship.

[0275] In addition to the above-mentioned STA MLD, the AP MLD also contains multiple other STA MLDs whose Link1 and Link2 are in a STR link relationship. Here, for convenience, the STA MLD whose Link1 and Link2 are in a non-STR link relationship is called non-STR MLD1, and the other multiple STA MLDs whose Link1 and Link2 are in a STR link relationship are called STRMLDs. STR MLDs can also include the AP MLD itself.

[0276] The MAC address in Link1 of non-STR MLD1 is STA1, and the MAC address in Link2 is STA2. The MAC address in Link1 of AP MLD is AP1, and the MAC address in Link2 is AP2.

[0277] The AP MLD has data to send to the non-STR MLD1. For example, Fig.21 As shown, first, STR MLDs obtains TXOP in Link1 ( Fig.21 "TXOP between STR MLDs"), Link 2 (idle) is not used.

[0278] AP MLD determines whether non-STR MLD1 is not communicating on Link1 (whether non-STR MLD1 is not a TXOP holder / responder). After confirming that non-STR MLD1 is not communicating on Link1, AP MLD performs DL transmission including a frame addressed to non-STR MLD1 on Link2 ( Fig.21 The frame is, for example, a data frame, an RTS frame, etc. The RTS frame is a type of control frame.

[0279] Assuming that non-STR MLD1 is communicating on Link 1, AP MLD does not perform DL transmission including a frame addressed to non-STR MLD1 on Link 2 until non-STR MLD1 stops communicating on Link 1.

[0280] Furthermore, although DL transmission includes a data frame addressed to non-STR MLD1, DL transmission of frames addressed only to non-STR MLD1 or DL ​​multi-user (MU) transmission also including frames addressed to other STA MLDs may be used.

[0281] In DL transmission in Link2, the RA of the frame addressed to non-STR MLD1 is of course STA2. In DL MU, in the PHY packet, the PHY header is used to notify the association identifier (AssociationIdentifier; hereinafter referred to as AID) assigned to STA2 or non-STR MLD. The PHY header is configured to receive a stream, a resource unit (Resource Unit; hereinafter referred to as RU) or a stream and the RU therein and decode it in each STA. The RA in the received decoded data frame specifies the MAC address of each STAMLD.

[0282] When DL transmission includes a frame addressed to other STA MLDs, and Link2 and Link1 in other STA MLDs are also in a non-STR link relationship, similarly to non-STR MLD1, the condition for executing DL transmission in Link2 is that other STA MLDs do not communicate in Link1. When Link2 and Link1 in other STA MLDs are in a STR link relationship, this condition is not required.

[0283] As described above, when AP MLD is about to start DL transmission including non-STR MLD1 in Link2 ( Fig.21Before the “DL including non-STR MLD1”, it is determined whether non-STR MLD1 is communicating in Link1. If it is confirmed that non-STR MLD1 is communicating in Link1, no interference will occur if DL transmission can be postponed.

[0284] However, due to the influence of installation, a time difference may occur in the control of Link 1 and Link 2. In this case, for example, if non-STR MLD1 is communicated in Link 1 by Priority Interframe Space (hereinafter referred to as PIFS) before the start of DL transmission including non-STR MLD1 in Link 2, DL transmission can be performed.

[0285] By doing so, the generation of interference when non-STR MLD1 communicates within PIFS cannot be avoided, but the interference can be minimized. PIFS is a frame interval (interframe space) that can be used only under conditions specified in wireless LANs that comply with the 802.11 standard. PIFS is specified as Short interframe space (hereinafter referred to as SIFS) + Slot time. SIFS is the minimum frame interval used when sending a response frame to a received data frame, and it is not necessary to grasp the carrier sense state. The Slot time is the minimum unit for backoff, and carrier sense is required. In the typical case of the 2.4GHz band, SIFS is 10us, Slot time is 20us, and PIFS is 30us. In the typical case of the 5GHz band, SIFS is 16us, Slot time is 9us, and PIFS is 25us.

[0286] If direct link communication is not performed in the BSS, it is sufficient for the AP MLD to determine whether the non-STR MLD1 does not communicate in Link1 (is not the TXOP holder / responder in Link1) by determining whether the MAC address in Link1 of the non-STR MLD1, i.e., STA1, is not included in the RA of the frame sent by itself, or if there is a TA in the frame addressed to itself, whether the MAC address in Link1 of the non-STR MLD1, i.e., STA1, is not included in the TA. This is because the communication partner in Link1 of non-STR MLDs must be the AP MLD.

[0287] Basically, direct link communication is an optional function, and considering that the frequency of use is low, it can be said that the above-mentioned judgment criteria are sufficient for the feasibility of DL transmission.

[0288] In addition, the possibility of using direct link communication can be determined by understanding the application used by the connected STA MLD, and the criterion for determining whether DL transmission is possible can be changed accordingly. For example, if it is determined that direct link communication is used, the APMLD determines whether the TA of the frame not addressed to itself does not contain the MAC address in Link1 of non-STR MLD1.

[0289] In addition, when AP MLD determines that non-STR MLD1 is communicating in Link 1 based on the address of the frame, it uses the network allocation vector (hereinafter referred to as NAV) set by the Duration field in the MAC header of the frame to grasp the end of the TXOP in Link 1. Before the end time, the wireless link that is in a non-STR link relationship with Link 1 and the transmission to non-STR MLD1 in Link 2 are not performed.

[0290] A data frame is one example of a typical frame that the AP MLD performs DL transmission on the non-STR MLD1. Fig. 22 An example of the basic structure of a data frame is shown below. Figure 3 The beacon frame shown similarly includes a MAC header, a Frame Body (variable length in octet units), and an FCS (4 octets).

[0291] The MAC header includes a Frame Control field (2 octets), a Duration field (2 octets), an Address 1 field (6 octets), an Address 2 field (6 octets), an Address 3 field (6 octets), a Sequence Control field (2 octets), an Address 4 field (0 or 6 octets), a QoS Control field (0 or 2 octets), and a HT Control field (0 or 4 octets).

[0292] The Frame Control field includes a Type subfield and a Subtype subfield. The AP MLD that sends a data frame uses the Type subfield as identification information of the data frame and uses the Subtype subfield as, for example, QoS Data.

[0293] The data received from the upper layer is set in the Frame Body.

[0294] Another representative example of a frame that the AP MLD performs DL transmission to the non-STR MLD1 is an RTS frame. Fig.23 An example of the basic structure of an RTS frame is shown below: The RTS frame includes a MAC header and an FCS (4 octets).

[0295] The MAC header includes a Frame Control field (2 octets), a Duration field (2 octets), an RA field (6 octets), and a TA field (6 octets). The RA field is the address of the STA that receives the data frame, management frame, or control frame that is scheduled to be sent after the RTS frame is sent. The TA field is the address of the STA that sends the RTS frame.

[0296] The Frame Control field includes the Type subfield and the Subtype subfield. The AP MLD uses the Type subfield as identification information of the control frame and the Subtype subfield as an identifier of the RTS frame.

[0297] As described above, when AP MLD determines that non-STR MLD1 does not communicate in Link 1 and performs DL transmission to the non-STR MLD1 target in Link 2, non-STR MLD1 can only perform reception decoding in Link 2. Therefore, even if the interference of Link 2 leaks to Link 1 in non-STR MLD1, the interference in Link 1 will not affect the operation of non-STR MLD1.

[0298] In such Fig.21 As shown, in the TXOP based on STR MLDs ( Fig.21 The "TXOP between STR MLDs" has ended, but the DL transmission containing data frames addressed to non-STR MLD1 continues in Link2 ( Fig.21 In the case of "DL including non-STR MLD1", it is considered that the interference component of the DL transmission leaks to Link 1, and in non-STR MLD1, CCA is busy in Link 1. However, in non-STR MLD1, it is not necessary to receive and decode in Link 1, so there is no influence.

[0299] In this situation, non-STR MLD1 may be blocked from obtaining access rights in Link 1. How to deal with this situation will be described later.

[0300] In addition, if non-STR MLD1 does not communicate in Link1 and Link1 is idle, AP MLD can of course also perform DL transmission including frames addressed to non-STR MLD1 in Link1. The frames sent DL are not limited to data frames, and can be RTS frames addressed to non-STR MLD1, or MU RTS frames (a type of trigger frame) including non-STR MLD1 in the target destination. In this case, AP MLD can also adjust so that the TXOP in Link1 ends at the same time as the end of the TXOP in Link2 or later than the end of the TXOP in Link2. As an example of adjustment, AP MLD can also include padding bits in the frames sent DL in Link2.

[0301] Fig.24 An example of the format of an A-MPDU generated by frame aggregation is shown. The A-MPDU includes a sequence of n (n is 1 or greater than 1) A-MPDU subframes and one EOFPadding (EOF padding) field of variable length in octets.

[0302] Each A-MPDU subframe includes an MPDU delimiter (4 octets), and an arbitrary MPDU (variable length in octets) follows the MPDU delimiter. A-MPDU subframes other than the last A-MPDU include a Padding field (0-3 octets) for making the length of the A-MPDU subframe 4n octets.

[0303] EOF Padding includes EOF Padding subframe (EOF filling subframe) (4n octets) and EOFPadding octet (EOF filling octet) (0-3 octets).

[0304] AP MLD can use these padding fields in the A-MPDU to adjust the frame length.

[0305] In addition, if the timing of non-STR MLD1 sending response frames in Link1 and Link2 is taken into consideration, AP MLD can also make the end time of sending data frames for DL ​​transmission consistent in Link1 and Link2, and the length of response frames from non-STRMLD1 consistent. If this is done, the data frames for DL ​​transmission and the response frames for UL transmission can be synchronized in Link1 and Link2.

[0306] 《DL transmission of AP MLD trigger frame》

[0307] exist Fig.21 In the description, AP MLD performs DL transmission on Link2 for a frame that includes non-STR MLD1 in the transmission destination. Fig.21 This assumes DL single user (DL SU) transmission or DL ​​multi-user (DL MU) transmission. However, the AP MLD may also send a trigger frame allowing UL transmission to a non-STR MLD1 or multiple STA MLDs including non-STR MLD1.

[0308] When AP MLD transmits a frame addressed to MAC address STA2 in Link2, and STA with MAC address STA2 receives the frame addressed to MAC address STA2, STA with MAC address STA2 transmits a response frame such as Ack or BlockAck to AP with MAC address AP2 UL after SIFS. In the case where the DL transmission performed by AP with MAC address AP2 in Link2 is a DL MU transmission including a frame addressed to MAC address STA2, and AP with MAC address AP2 requests a response frame from STA MLD, which is the transmission target of the DL frame of DL MU communication, AP with MAC address AP2 may also include a trigger frame indicating UL MU transmission of the response frame in the DL MU transmission. The trigger frame requesting the response frame is a category such as multi-user block acknowledgement request (referred to as MU-BAR). By receiving MU-BAR, a response frame is transmitted using UL MU in each STA.

[0309] exist Fig.21 In the UL, such a case is also included and recorded as "UL including non-STR MLD1". In addition, when the STA with MAC address STA2 in Link2 sends a response frame to UL, it is considered that the STA with MAC address STA1 in the same non-STRMLD1 cannot normally perform carrier sense (CarrierSense; hereinafter referred to as CS) of the wireless medium in Link1. Fig.21 “non-STR MLD1 can't CS (non-STR MLD1 cannot CS)”).

[0310] However, there are two types of CS in wireless LANs that comply with the 802.11 standard. One is a physical CS that directly monitors whether the wireless medium is busy or idle. The other is a virtual CS that sets NAV based on the time length notified by the Duration field of the received frame, etc., from the end time of the PHY packet containing the frame to the end time of the notified time length. In the case where two wireless links are in a non-STR link relationship in MLD, when the frame is sent via the first link, the CS in the case where normal CS cannot be performed in the second link is called a physical CS. In the physical CS, the status of the CCA is checked to see if it is busy or idle.

[0311] The trigger frame is a type of control frame. The trigger frame indicates the uplink (Up Link; hereinafter referred to as UL) MU transmission to the STA MLD. When instructing multiple terminals to transmit UL MU, the frame initially sent by the AP is the trigger frame. The AP uses the trigger frame to instruct the STA MLD which STA can perform UL MU transmission, what the packet length of the UL MU transmission should be, what MCS each STA uses, etc. The AP here can be the AP MLD. The STA here can be the STA MLD.

[0312] When UL MU transmission is performed after the trigger frame is sent, the access right for performing UL MU transmission has been obtained by the AP MLD that sent the trigger frame, so the AP MLD's judgment on whether to obtain the access right in Link2 is the same as the case of the aforementioned DL frame transmission. If the AP MLD is notified in advance of the STA MLD's UL transmission request to the AP MLD, the APMLD can schedule the transmission of the trigger frame to the STA MLD. Furthermore, the STA MLD can also request the AP MLD in advance in which wireless link it wants to receive the trigger frame or negotiate with the AP MLD in advance in which wireless link it wants to receive the trigger frame. In this case, Fig.21 This is the state after determining which link to use.

[0313] Fig.25 The format of the trigger frame is shown in FIG. The trigger frame includes a MAC header, a Common Info field (8 octets or more), a User Info List field (variable length in octets), a Padding field (variable length in octets), and an FCS field (4 octets).

[0314] The MAC header field includes a Frame Control subfield (2 octets), a Duration subfield (2 octets), a RA subfield (6 octets), and a TA subfield (6 octets). The Common Info field includes a ULLength subfield. The User Info List field includes User Info subfields greater than 0, and each User Info subfield includes an AID12 subfield, a UL HE-MCS subfield, and the like. In addition, regarding the AID subfield, when set in the MAC header, its length has the same 2 octets as the Duration field, and is set instead of the Duration field. However, in fact, the range of AIDs assigned by the AP to the STA is 1 to 2007, so the AID12 subfield used to indicate the AID of the STA in the User Info subfield of the trigger frame is sufficient to be 12 bits, and is set to 12 bits.

[0315] The AP MLD specifies the AID of each STA MLD in the AID12 subfield, specifies the MCS used when sending UL MU in the UL HE-MCS subfield, and specifies the PHY packet length in the UL Length subfield.

[0316] When the User Info field specifies one terminal as the destination terminal of the trigger frame, RA is the address of the one terminal. When the User Info field specifies multiple terminals as the destination terminals of the trigger frame, RA is a broadcast address.

[0317] In the AID12 subfield, the association ID assigned to the STA MLD is set. The association ID does not specify the MAC address, but specifies the STAMLD. Strictly speaking, it specifies the STA of the link corresponding to the STA MLD. After the STA MLD sends the association request frame to the APMLD, when the AP MLD sends the association response frame to the STA MLD to accept the request, the AP MLD assigns the association ID to the STA MLD. This association ID is commonly used in all wireless links used in the STA MLD.

[0318] The AP MLD transmits a trigger frame to the non-STR MLD1 after confirming that the non-STR MLD1 is not communicating on the main link, similarly to when transmitting a data frame.

[0319] When an association ID is assigned from the AP MLD and its own association ID is set in the AID12 subfield, the STA MLD that receives the trigger frame recognizes that it is the target of UL MU transmission and performs UL MU transmission after SIFS from the end time of the PHY packet containing the trigger frame.

[0320] In addition, as a method of sending a trigger frame, the AP MLD may also send it without specifying a separate STAMLD in the AID12 subfield. In this case, the STA MLD on the receiving side of the trigger frame may also use a random number to decide whether to send it. This sending method is called UL OFDMA (Orthogonal Frequency Division Multiple Access) based Random Access (hereinafter referred to as UORA). In this case, for example, if non-STR MLD1 does not communicate in Link1, STA2 that receives the trigger frame specifying UORA can perform UL transmission.

[0321] 《CS resume (outline) example in Link 1 of non-STR MLD1》

[0322] As a method for non-STR MLD1 to avoid the possibility of CS not fully functioning due to the CCA of the wireless medium in Link1 being in an unclear state, which may cause a conflict with the transmission of other STAs, there is a method in which, for example, even if the state of CCA in Link1 is determined to be idle for a fixed time from the interference of Link2 or the end of Link2's TXOP, the execution of CSMA / CA is retained, and normal CSMA / CA is executed after the fixed time has passed.

[0323] In a wireless LAN that complies with the 802.11 standard, as described above, a TXOP has been obtained by another STA, but it is not recognized in the physical CS, and sometimes the terminal performs transmission. This situation occurs when the terminal of the node transitions from the doze state to the awake state, when the channel is switched, etc. In order to prevent this, a fixed time such as NAVSyncDelay is defined. The concept of the first method is the same as that of NAVSyncDelay, and this method can also be used.

[0324] NAVSyncDelay can be specified by the AP (AP MLD when it is applied to multi-link communication) and the STA (STA MLD when it is applied to multi-link communication). Depending on the specification, it can sometimes become extremely short, so there are still cases where it is not appropriate to avoid conflicts. In addition, it cannot be shared as a common time within the BSS. As a second method, other parameters containing values ​​can also be defined as wireless LAN standards. Alternatively, the value of the new parameter can be set by the AP MLD and notified to the surrounding STA MLDs using a beacon frame or the like. When the AP MLD uses a beacon or the like to notify the fixed time length, for example, the aforementioned ML element, EHT Capabilities element, or a new information element can be used.

[0325] If other frame reception can be detected and NAV can be acquired during the waiting period of the fixed time, the waiting period of the fixed time can be cancelled because the purpose is achieved by synchronizing with other STAs regarding the use status of the wireless medium.

[0326] As a third method, when CSMA / CA is restarted from the moment when the interference from Link2 ends, the sensitivity can be increased compared to the previous CS level, that is, the CS threshold can be lowered compared to the previous one. In the past, in a wireless LAN that complies with the 802.11 standard, the CS level for detecting the PHY packet of the wireless LAN that complies with the 802.11 standard was specified as -82dBm / 20MHz, and the CS level for detecting the signal containing other noise was specified as -62dBm / 20MHz. However, when CSMA / CA is restarted in Link1 from the moment when the interference from Link2 ends, the physical CS level can be uniformly set to, for example, -82dBm / 20MHz. At this time, when a MAC frame is received in Link1 and it is determined that the CS state is grasped in the same way as other terminals that can perform CS normally, the operation of CSMA / CA using the normal CS threshold can be immediately restored.

[0327] In these examples, the STA with MAC address STA1 needs to grasp the transmission end time of STA2 in Link 2. Therefore, for example, the occupancy length or end time of the PHY packet transmitted by the STA with MAC address STA2 in Link 2 can be shared with the STA with MAC address STA1 in Link 1.

[0328] When sending a response frame, the STA with MAC address STA2 can obtain the TXOP length obtained between the AP with MAC address AP2 and the STA with MAC address STA2, or can obtain the end time of TXOP in Link2 from NAV information (described later). Using this, in the fourth method, the TXOP length or the end time of TXOP is shared with the STA with MAC address STA1 of Link1. Accordingly, the STA with MAC address STA1 can perform an action of waiting for a fixed time from its end time or an action of increasing CS sensitivity from its end time. For example, the information is shared from the lower MAC processing unit 38 that processes the access control of Link2 to the lower MAC processing unit 36 ​​that processes the access control of Link1.

[0329] As a fifth method of recovering from a situation where the STA with MAC address STA1 cannot accurately grasp the CS state in Link1, the AP MLD may notify the STA with MAC address STA2 of the NAV state in Link1 in a frame sent to MAC address STA2 in Link2. This is because there is no non-STR link relationship between Link1 and Link2 in the AP MLD. The STA MLD grasps the timing of the end of the TXOP in Link1 based on the NAV information in Link1. For example, when the end timing based on the NAV information is earlier than the end timing of the situation where the CCA cannot be grasped, the STA MLD implements normal CSMA / CA from the time point when the CCA can be grasped without waiting for the above-mentioned fixed time. When the end timing based on the NAV information is later than the end timing of the situation where the CCA cannot be grasped, the STA MLD waits for the end timing based on the NAV information to implement normal CSMA / CA.

[0330] 《Delay of DL transmission from AP MLD to non-STR MLD1》

[0331] Fig.21 This shows that when AP MLD sends the next data frame addressed to non-STR MLD1, it determines whether non-STR MLD1 is communicating in Link1 and confirms that non-STR MLD1 is performing UL transmission in Link1 ( Fig.21 "ULfrom non-STR MLD1 (UL from non-STR MLD1)").

[0332] There are several ways for AP MLD to deal with this situation. The first example is a case where AP MLD does not perform transmission itself in Link 2 until transmission to the STA having MAC address STA1 can be performed in Link 1. As a result, transmission to non-STRMLD1 is postponed.

[0333] The second example of the response of AP MLD is when AP MLD has data addressed to other STAs, it transmits a management frame or a data frame to other STAs on Link 2. As a result, transmission to the STA of non-STR MLD1 is also postponed.

[0334] Other STAs refer to (1) other non-STR MLD STAs that do not transmit in Link1, (2) other non-STR MLD STAs whose Link1 and Link2 are in a STR link relationship, (3) STR MLD STAs that can maintain a STR link relationship in all wireless links, or (4) STAs that are connected to AP2 only in Link2.

[0335] As an application of the second example, there is a condition. The second example can be applied when non-STR MLD1 can use the PHY header of the PHY packet received by one of the two wireless links in the non-STR link relationship, can perform automatic gain control (hereinafter referred to as AGC), and can continue frame exchange in Link1 in a state where synchronization for reception and decoding is obtained. In addition, whether frame exchange can be continued in Link1 depends on the signal-to-interference ratio (hereinafter referred to as SIR) condition.

[0336] However, depending on the installation, it is possible that when one link participates in the TXOP, it may interfere with other links. For example, in a wireless LAN chip that can also transmit and receive radio waves of the Bluetooth (registered trademark) standard, it is considered that the Bluetooth signal is surrounded by the antenna of the wireless LAN and the Bluetooth signal is distorted. In this case, when sending Bluetooth radio waves, the low noise amplifier (hereinafter referred to as LNA) on the wireless LAN side can be turned off. When transmitting and receiving in Link1, the same response can be performed in Link2. In other words, when transmitting and receiving in Link1, the LNA of Link2 can be turned off.

[0337] STA-MLD may also notify AP MLD in advance whether such response can be performed. STA-MLD may also notify this information when using ML elements, etc. to notify that two wireless links are in a non-STR link relationship. STA-MLD may also notify this information in a summary as a capability of STA MLD. An example of an element that is notified in a summary is the EHT Capabilities element. The EHT Capabilities element is also set in the association request frame and the reassociation request frame.

[0338] As a method of transmitting to non-STRMLD1 in Link2 without interfering with the communication in Link1 of non-STRMLD1, AP MLD applies transmit beamforming to the transmission in Link2, and a null value (null) sometimes points to the communication in Link1 of non-STRMLD1 (zeroing). Alternatively, spatial reuse (hereinafter referred to as SR) of the 802.11ax standard can also be applied. SR is a method of adjusting the CS sensitivity to match the transmission power of this terminal. In addition, SR is also a method of judging the resistance to interference from self-transmission of other terminals based on the information obtained from the received frame, and when it is judged that the resistance is sufficient (there is no problem as SIR), it is possible to send the received frame repeatedly in time.

[0339] 《Transmission of a wireless link that is in a STR link relationship with the main link in STA MLD》

[0340] In the transmission from the AP MLD to the STA MLD in which Link1 and Link2 are in a STR link relationship, the STA MLD can independently transmit and receive on Link1 and Link2. Therefore, the AP MLD does not need to determine whether the STA MLD is communicating on Link1.

[0341] As described above, according to the first embodiment, the AP MLD obtains the link information of the wireless link in the non-STR link relationship from the non-STR MLD. The AP MLD sets one of the wireless links expected to be in the non-STR link relationship as the main link, and notifies the non-STR MLD of the information of the main link. In the state where the sub-link and the main link in the non-STR MLD are in the non-STR link relationship, when sending to the non-STR MLD in the sub-link other than the main link, the AP MLD determines whether the non-STR MLD is not communicating in the main link. In the case where the non-STR MLD is communicating in the main link, the sending is postponed.

[0342] As a result, when AP MLD sends to non-STR MLD, it can determine whether to send by simply checking the communication status of the main link. Therefore, it is possible to avoid conflicts between wireless links in a non-STR link relationship and ensure the performance of non-STR MLD. In addition, non-STR MLD can fully enjoy the benefits of multi-link without the presence of wireless links in a non-STR relationship.

[0343] (Second embodiment)

[0344] In the first embodiment, the STA MLD directly notifies the AP MLD which wireless link is in a non-STR link relationship with respect to a certain wireless link. In the second embodiment, the STA MLD does not directly notify the AP MLD which wireless link is in a non-STR link relationship with respect to a certain wireless link, but indirectly notifies the two wireless links in a non-STR link relationship by notifying the AP MLD of the separation distance in frequency at which the two wireless links become a non-STR link relationship or a STR link relationship.

[0345] The STA MLD notifies the AP MLD of the method of treating two wireless links whose frequency separation distance is greater than a threshold distance as wireless links in a non-STR relationship. The AP MLD determines which two wireless links are non-STR links based on the relationship between the link IDs and link frequencies of the wireless links being used. Fig.21 When sending as shown, the frequency separation distance between Link1 and Link2 is used to determine whether Link1 and Link2 are in a non-STR link relationship or a STR link relationship for the STA MLD. The STA MLD notifies the threshold distance, and the AP MLD compares the separation distance with the threshold distance. If the separation distance is greater than the threshold distance, the AP MLD determines that the two wireless links are in a non-STR link relationship.

[0346] Fig.26 An example of the format of the ML element included in the association request frame sent by the STA MLD to the AP MLD is shown.

[0347] The ML element includes the Element ID field (1 octet), the Length field (1 octet), the ElementID Extension field (1 octet), the STA MLD field (6 octets), the Max Non-STR Frequency Difference field (maximum Non-STR frequency difference) (1 octet), the Number Of Links field (1 octet), and the Link ID Set field (variable length in octets). In addition, the Link ID subfield contained in the Link ID Set field is fixed. In addition, if it is guaranteed that no other fields will be added after the Link ID Set field, the Number Of Links field can also be omitted. The area until the end of the ML element remaining after the Non-STR Frequency Difference field is set as the Link ID Set field, and it is divided for each fixed length of the Link ID subfield and treated as a Link ID subfield respectively.

[0348] The Max Non-STR Frequency Difference field notifies the threshold distance of the maximum frequency separation distance between two wireless links that become non-STR links. If the frequency separation distance between wireless links is less than the threshold distance notified by this field, the AP MLD determines that these wireless links are in a Non-STR link relationship in the STA MLD. If the frequency separation distance between wireless links is greater than the threshold distance, the AP MLD determines that these wireless links are in a STR link relationship in the STAMLD.

[0349] The field name may also be changed to a field name such as Min STR Frequency Difference to mean "a threshold distance indicating the minimum separation distance on the frequency that constitutes an STR link relationship". In this case, if the frequency separation distance between wireless links is greater than the threshold distance notified by this field, the AP MLD determines that these wireless links are in an STR link relationship in the STA MLD. If the frequency separation distance between wireless links is less than the threshold distance notified by this field, the AP MLD determines that these wireless links are in a non-STR link relationship in the STA MLD.

[0350] Hereinafter, the Max Non-STR Frequency Difference field name will be described. However, even if the MinSTR Frequency Difference field name is used, only the perspective of the notification content is different, and other contents are applied in the same manner.

[0351] For example, if the frequency separation distance is less than 240 MHz, the STA MLD notifies the AP MLD that the two wireless links have become non-STR links using the Max Non-STR Frequency Difference field. Fig.26 1 octet is prepared in. For example, when the channel width is set to 80MHz, the channel of the frequency band of 0 to 20.4GHz can be expressed with a value of 0 to 255. If you want to express 240MHz as the threshold distance, the value of this field is 3. It is meaningless to express 0MHz with this field, so the value representing 0HMz can also be used for other purposes or set to Reserved.

[0352] For example, if the wireless system targets only the 2.4 GHz to 6 GHz bands, it is sufficient to express 5 GHz as the threshold distance. Therefore, values ​​other than the value indicating 5 GHz are used for other purposes or are set as Reserved.

[0353] Instead of the 80 MHz unit, a wireless system may use other fixed values ​​as units, such as 20 MHz units. In addition, a part of the bit area of ​​the field may be used to identify the channel unit, and the remaining bit area may be used as a value indicating the threshold distance.

[0354] For example, the area may be identified by the first 3 bits, with 0 being Reserved, 1 being 20 MHz, 2 being 40 MHz, 3 being Reserved, 4 being 80 MHz, and 5 to 7 being Reserved. The value expressed by the remaining 5 bits is multiplied by the unit to calculate the frequency separation distance.

[0355] If up to 160 MHz is used as a unit, for example, for the 3 bits, 0 is set to Reserved, if it is 1, it is set to 20 MHz, if it is 2, it is set to 40 MHz, 3 is set to 80 MHz, 4 is set to 160 MHz, 5 to 7 are set to Reserved, and so on.

[0356] If STA MLD can consider the installation design, etc., and know in advance whether it can be guaranteed that the two wireless links will become non-STR links if the frequency separation distance is within a certain range, or the wireless links will become STR links if they are far apart, such notification can be made.

[0357] If it is the former, the notification method is as in the Max Non-STR Frequency Difference field, and if it is the latter, the notification method is as in the Min STR Frequency Difference field.

[0358] exist Fig.26 In the , after the Max Non-STR Frequency Difference field, the NumberOf Links field and the Link ID Set field are sequentially configured. The Max Non-STR Frequency Difference field exists in these fields, so that Fig.19 The Non-STR Link1 subfield and the Non-STR Link2 subfield of the Fig.19 The field name of the ML element is changed. The Number Of Links field indicates the number of LinkID subfields contained in the subsequent Link ID Set field. The Link ID Set subfield includes a single or multiple Link ID subfields. Fig.11 The Link ID subfield is the same as the

[0359] The STA MLD uses the Link ID subfield to notify the AP MLD of the ID of the single or multiple wireless links used in the STA MLD among the multiple wireless links notified from the AP MLD. Fig.11 , 7 octets are required after the STA MLD field. Fig.26 If the format is different, then after the STAMLD field, 4 octets are acceptable, thereby shortening the field size. Shortening the field size also helps improve the efficiency of wireless communications.

[0360] The frequency separation distance notified using the Max Non-STR Frequency Difference field is, for example, a difference between the center frequencies of channels used by each wireless link. The frequency separation distance notified may also be changed to indicate the difference between the closest ends of channels used by each wireless link.

[0361] When the AP MLD receives the following from the STA MLD: Fig.26 When such an association request frame containing an ML element is received, the frequency separation distance between wireless links notified by the own device is compared with the frequency separation distance notified by the Max Non-STR Frequency Difference field to understand which two wireless links are in a Non-STR link relationship in the STA MLD.

[0362] Fig. 27 The 5 GHz frequency band of a wireless LAN that complies with the 802.11 standard is shown. In the case of an 80+80 MHz channel, the Fig. 27 For example, the AP MLD notifies the STA MLD of the channel number 106 as Link 1 and the channel number 138 as Link 2. If the frequency separation distance is less than 240 MHz, the STA MLD uses the Max Non-STR Frequency Difference field to notify the AP MLD that the two wireless links are non-STR links.

[0363] When the Max Non-STR Frequency Difference field is set to be expressed as the difference in center frequency, in APMLD, the center frequency of channel number 106 is 5,530 MHz, and the center frequency of channel number 138 is 5,690 MHz. The frequency separation distance is 160 MHz, which is less than 240 MHz. Therefore, it is understood that Link 1 and Link 2 are in a non-STR link relationship in STR MLD.

[0364] Of course, the STA MLD that sends this information also knows that Link1 and Link2 are in a non-STR link relationship as its own device. For example, similar to the first embodiment, when the AP MLD sets Link1 as the main link, the STA MLD sends Link1 as the main link. When sending to the STA MLD, the AP MLD determines whether the STA MLD is communicating in Link1 and performs access right acquisition based on it.

[0365] According to the second embodiment, since the STA MLD indirectly notifies the AP MLD of the wireless link in the relationship of non-STR / STR link, the size of the notification information is reduced, and the communication efficiency is improved.

[0366] (Third embodiment)

[0367] In the first embodiment, the AP MLD sets one of the multiple wireless links used by the device as the main link and notifies the STA MLD. In this embodiment, the AP MLD indirectly notifies the STA MLD of the main link by accepting the association request for connection request from the STA MLD only in the main link, thereby omitting the direct notification of the first embodiment.

[0368] Specifically, the AP MLD transmits an association response frame in response to the association request frame, but adds a condition that the association request frame is received in the primary link as one of the conditions for transmitting the association response frame whose Status Code is a value indicating "SUCCESS".

[0369] Association request frame with Figure 3 The beacon frame of the MAC header also includes a MAC header, a Frame Body, and an FCS. The Type subfield of the frame control field included in the MAC header records the identification information of the management frame, and the Subtype subfield records the identification information of the association response. The Frame Body of the association request frame includes a StatusCode indicating whether the association request action is successful or failed.

[0370] When the STA MLD sends an association request frame in the secondary link, the AP MLD sends an association response frame with a Status Code indicating a value of "NG". When the STA MLD receives an association response frame with a Status Code indicating a value of "NG", it identifies that the wireless link through which the association request frame was sent (or the association response frame was received) is not the primary link, changes the wireless link and resends the association request frame to request a connection again. When the STA MLD receives an association response frame with a Status Code indicating a value of "SUCCESS", it identifies that the wireless link through which the association request frame was sent (or the association response frame was received) is the primary link.

[0371] By doing so, it is possible to omit the transmission of the Reduced NeighborReport element for notifying the STA MLD of the main link from the AP MLD, thereby achieving improved efficiency of wireless communication.

[0372] Fig.28An example of Status Code of the wireless LAN standard is shown. Each code of the Status Code is assigned to each value. As an example, the SUCCESS code, which means success, is assigned to 0, REFUSED (rejected) and REFUSED_REASON_UNSPECIFIED (rejection reason unknown) which mean failure and failure with unclear reasons are assigned to 1, TDLS_REJECTED_ALTERNATIVE_PROVIDED (TDLS refuses to provide alternative) which means Tunneled Direct Link Setup (hereinafter referred to as TDLS) wake-up schedule rejection (there is an alternative schedule) is assigned to 2, TDLS_REJECTED which means TDLS wake-up schedule rejection is assigned to 3, and SECURITY DISABLED which means security disabled is assigned to 4. Currently, there are several Reserved values ​​to which no code is assigned. For example, no code is assigned to 4, 8, 9, 20, 21, ...

[0373] Fig.29 An example of Status Code in the third embodiment is shown. A code such as "DENIED_NOT_PRIMARY_LINK" which means rejection because it is not the primary link is assigned to any value among the currently reserved values, in this case 4. When the STA MLD transmits an association request frame in the secondary link, the AP MLD transmits an association response frame with 4 in the Status Code.

[0374] In addition, in order to notify the STA MLD of the main link, the AP MLD may also add an information element with information about the main link (such as the Channel Number) to the association response frame when sending the association response frame with the Status Code having 4 to the STA MLD. If this is done, the STA MLD can identify the main link without receiving the association response frame with the Status Code having 4 multiple times.

[0375] As a means of preventing the STA MLD from sending the association request frame in the secondary link, the AP MLD may send the beacon frame in the main link but not the beacon frame in the secondary link. When the beacon frame is not sent, the legacy STA does not send the association request frame either. For example, in the case where only the STA MLD corresponding to the MLO is allowed to send the association request frame in the secondary link, the AP MLD may send a management frame (the frame type is different from the beacon frame) of a category not recognized by the legacy STA to the STA MLD instead of the beacon frame to notify that the sending of the association request frame is allowed.

[0376] Even in the Fig.18A When there are multiple main links, the AP MLD may also accept association requests from the AP MLD in Link 1 and Link 4 which are the main links, and may not accept association requests in Link 2 and Link 3 which are the secondary links.

[0377] When the AP MLD indirectly notifies the information of the primary link in Link1 and Link4, the STA MLD knows that Link1 and Link4 are the primary links. If the STA MLD can establish a connection by sending an association request frame in Link1, it is not necessary to send an association request frame in Link4.

[0378] According to the third embodiment, AP MLD does not notify STAMLD of the identifier of the wireless link set as the main link, but instead indirectly notifies the main link, so the size of the notification information is reduced, achieving efficient communication.

[0379] (Fourth embodiment)

[0380] In the first embodiment, when performing DL MU transmission in a certain secondary link, the AP MLD determines whether the target STA constitutes a STA MLD in which the secondary link and the main link become a non-STR link (in Fig.21 In the figure, only MLD1 is described.

[0381] In the fourth embodiment, when the AP MLD constructs a PHY packet for DL ​​MU transmission on a certain sub-link, the AP MLD makes the SAT MLD, which is the transmission target of the DL MU transmission, become only the STA MLD in which the sub-link and the main link are in a STR link relationship or only the STA MLD in which the sub-link and the main link are in a non-STR link relationship. That is, the STA MLD in which the sub-link and the main link are in a STR link relationship and the STA MLD in which the sub-link and the main link are in a non-STR link relationship are not mixed in the transmission target of the PHY packet sent by the AP MLD in the sub-link.

[0382] To achieve this, the AP MLD creates in advance, for each sub-link, a table of STA MLDs indicating a relationship in which the main link and the sub-link become non-STR links.

[0383] According to the STA MLD, the main link and the secondary link become both STR links and non-STR links. When the AP MLD wants to perform DL transmission on the secondary link, it can check the table and determine whether it is necessary to check the communication status of the main link.

[0384] Fig. 30A An example of a table showing addresses of STA MLD groups in which the main link and the secondary link are non-STR links for a certain secondary link is shown. Here, the MLDMAC address assigned to the upper MAC processing unit 40 is used as the address. Fig. 30B This is a table showing the MLD MAC addresses of the STA MLD group in which the main link and the sub-link form an STR link with respect to a certain sub-link.

[0385] By doing so, when multiple STA MLDs are sent as DL MU transmission targets, the communication status of the main link can be investigated intensively. When the AP MLD performs DL MU transmission of a PHY packet in a sub-link that targets only the STA MLD that has a STR link relationship with the main link, it is possible to omit the judgment of whether the STA MLD that is the transmission target is communicating in the main link.

[0386] Fig.31A , Fig.31B , Fig.32 Another example of a table created by the AP MLD is shown. When performing DL MU transmission, when generating a MAC frame, the destination MAC address RA of the MAC header is required. In addition, when performing DL MU transmission, when generating a PHY packet, an association identifier AID is required in the PHY header. Therefore, the AP MLD can also create a table with this information. Fig.31A This is a table showing, with respect to a certain sub-link, the MLD MAC address of the STA MLD group in which the main link and the sub-link are in a non-STR link relationship, the MAC address in the sub-link, and the AID. Fig.31B This is a table showing the MLD MAC addresses of the STA MLD group, the MAC addresses in the sub-link, and the AIDs in the sub-link, which show the relationship between the main link and the sub-link as the STR link. STA1-2 shows the MAC address in the sub-link (Link2) of the terminal STA MLD with the MLD MAC address of MLD1. AID1-2 shows the AID in the sub-link (Link2) of the terminal STA MLD with the MLD MAC address of MLD1.

[0387] and then, Fig.32 Show that Fig.31A , Fig.31B An example of summarizing into a table. Fig.32 The table shows a table in which STA MLD groups in which the main link and the sub-link form a non-STR link relationship and STA MLD groups in which the main link and the sub-link form a STR link relationship are aggregated for each MLD MAC address with respect to a certain sub-link. Fig.32 The table includes the MLD MAC address of the STA MLD, the MAC address in the main link (Link1), the AID in the main link (Link1), the MAC address in the secondary link (Link2), the AID in the secondary link (Link2), and a flag indicating whether the secondary link is in a non-STR link relationship relative to the main link.

[0388] In the above description, AP MLD simplifies the judgment of whether DL transmission is possible by preventing STA MLDs in which the sub-link and the main link become STR links and STA MLDs in which the sub-link and the main link become non-STR links from being mixed in the sending destination of the PHY packet sent in a certain sub-link.

[0389] The following describes an example of how AP MLD simplifies the judgment of whether DL transmission can be performed even when the sending targets of the PHY packet sent in a certain sub-link include a mixture of STA MLDs in which the sub-link and the main link have a STR link relationship and STAMLDs in which the sub-link and the main link have a non-STR link relationship.

[0390] The AP MLD aggregates the STAs constituting the STA MLD in which the secondary link and the main link form a non-STR link in the first half of the stream processing sequence of Multi-Input Multi-Output (hereinafter referred to as MIMO).

[0391] If this is done, when AP MLD detects in flow processing that the processing of the STA constituting STA MLD in which the sub-link and the main link are in a non-STR link relationship is transferred to the processing of the STA constituting STAMLD in which the sub-link and the main link are in a STR link relationship, AP MLD does not need to confirm the communication status of the main link thereafter and can simplify the processing.

[0392] For example, when AP MLD performs DL transmission in MU MIMO, STA MLD is allocated for each stream. In this allocation, AP MLD allocates STA MLD in a non-STR link relationship before processing a certain stream, and allocates STA MLD in a STR link relationship from the processing of subsequent streams. Before processing a certain stream, AP MLD checks whether the sub-link and the main link are in a non-STR link relationship or a STR link relationship in the STAMLD composed of STAs. Then, when it is detected that the sub-link and the main link are in a non-STR link relationship, AP MLD must confirm the communication status in the main link of the STA MLD.

[0393] However, when it is detected in the processing of a certain flow that the sub-link and the main link are in a STR link relationship, in the processing of subsequent flows, the sub-link and the main link are in a STR link relationship, so there is no need to judge the non-STR / STR link relationship between the sub-link and the main link, and there is no need to confirm the communication status in the main link.

[0394] The same applies to the case where the wireless communication device adopts OFDMA with frequency multiplexing. In the case of OFDMA, APMLD allocates RUs to STA MLDs in order from high to low frequency or from low to high frequency. AP MLD allocates RUs up to a certain frequency to STA MLDs in a non-STR link relationship, and RUs of subsequent frequencies are allocated to STA MLDs in a STR link relationship. AP MLD processes OFDMA RUs in order from high to low frequency or from low to high frequency.

[0395] If this is done, the AP MLD checks whether the sub-link and the main link are in a non-STR link relationship or a STR link relationship in the STA MLD composed of the STA before processing a certain RU in the processing of the RU of OFDMA. When it is detected that they are in a non-STR link relationship, the communication status in the main link of the STA MLD must be confirmed. However, when it is detected that the sub-link and the main link are in a STR link relationship, the sub-link and the main link are in a STR link relationship in the subsequent processing of the RU, so there is no need to determine the non-STR / STR link relationship between the sub-link and the main link, and there is no need to confirm the communication status in the main link.

[0396] Fig.33 This is a flowchart showing an example of processing when the AP MLD classifies the STA MLD into the STA MLD in which the main link and the sub-link are in a non-STR link relationship and the STA MLD in which the main link and the sub-link are in a STR link relationship.

[0397] The AP MLD determines whether the destination of the DL MU packet is the STA MLD group whose secondary link and primary link are in a non-STR link relationship. Fig.33 112). When the transmission target is not a STA MLD group in a non-STR link relationship, the AP MLD performs DL transmission of the PHY packet after acquiring the channel right ( Fig.33 of 120).

[0398] When the transmission destination is a STA MLD group in a non-STR link relationship, the AP MLD determines whether a TXOP ( Fig.33 114). When the TXOP is not obtained in the main link, the AP MLD performs DL transmission of the PHY packet after obtaining the channel right ( Fig.33 of 120).

[0399] When a TXOP is acquired in the primary link, the AP MLD determines whether the destination of the PHY packet contains the same MLD as the TXOP holder / responder of the primary link. Fig.33 116). When the MLD that is the same as the TXOP holder / responder of the primary link is not included in the transmission target of the PHY packet, the AP MLD performs DL transmission of the PHY packet after acquiring the channel right ( Fig.33 of 120).

[0400] When the same MLD as the TXOP holder / responder of the main link is included in the transmission target of the PHY packet, the AP MLD regenerates the PHY packet for DL ​​MU transmission in a manner that the same MLD as the TXOP holder / responder of the main link is not included in the transmission target of the PHY packet, or postpones the transmission until the TXOP in the main link of the same MLD as the TXOP holder / responder ends ( Fig.33 118). After the processing is completed, the AP MLD obtains the channel right and then sends the PHY packet to the DL ( Fig.33 of 120).

[0401] (Fifth embodiment)

[0402] In this embodiment, the AP MLD considers the frequency separation distance between the wireless links when selecting multiple wireless links to be used in multi-link communication. For example, the AP MLD selects wireless links whose frequency separation distance is greater than a certain fixed value in a manner that all two wireless links become STR links among many connected STA MLDs. The fixed value may also be specified in accordance with the standard.

[0403] For example, when the AP MLD selects two wireless links, the 5.2 GHz band and the 5.3 GHz band, as wireless links for multi-link, the frequencies of the two wireless links are close, so in most of the STA MLDs connected to the AP MLD, the two wireless links become non-STR links. Therefore, as a method for the AP MLD to select wireless links for multi-link, a wireless link with a frequency as far away as possible, such as the 5.2 GHz band and the 5.6HGz band, is selected.

[0404] According to the fifth embodiment, the AP MLD selects wireless links with a frequency separation distance of at least a certain level for multi-link communication. Therefore, in the STA MLD, wireless links rarely become non-STR links.

[0405] (Sixth Implementation Method)

[0406] In this embodiment, when the AP MLD connects to the STA MLD, an upper limit is set for the number of STA MLDs whose primary link and secondary link are no-STR links. If the number of STA MLDs connected exceeds the upper limit, the APMLD does not allow the STA MLD to connect even if it receives an association request frame.

[0407] When the AP MLD does not allow the connection, it notifies the STA MLD of the reason using the Status Code of the association response frame. Fig.34 An example of Status Code in the sixth embodiment is shown. A code such as "DENIED_EXCEED_MAX_VALUE" which means that the number of STA MLD connections whose main link and sub-link are in a non-STR link relationship exceeds the upper limit and is rejected is assigned to any value among the currently reserved values, in this case 8. When the number of STA MLD connections whose main link and sub-link are in a no-STR link relationship exceeds the upper limit, the AP MLD sends an association response frame with 8 recorded in the Status Code to the STA MLD.

[0408] The STA MLD knows the reason why the association request is rejected, and thus can prevent useless retransmission of the association request frame.

[0409] In some cases, the sub-links used by the STA MLD are different, so the upper limit of the number of connections of the STA MLD may be limited for each sub-link.

[0410] (Seventh Implementation Method)

[0411] In this embodiment, for STA MLDs whose primary link and secondary link are in a non-STR link relationship, autonomous decentralized acquisition of access rights by CSMA / CA is suppressed, thereby making it easier for the AP MLD to perform DL transmission to such STA MLDs.

[0412] For example, there is a mechanism for improving the efficiency of AP MLD in UL MU of the 802.11ax standard, but in the embodiment, this mechanism is used to make it difficult for STA MLD to be autonomously transmitted.

[0413] As one of the specific examples, it is difficult to send a frame to the STA MLD in the main link before receiving a trigger frame. Since the transmission of the STA MLD is suppressed in the main link, it is easy for the AP MLD to determine the communication state of the main link.

[0414] In another specific example, MU Enhanced Distributed Channel Access (hereinafter referred to as EDCA) parameters included in the Frame Body of the management frame may be adjusted. Fig.35 The format of an example of a MU EDCA parameter group element is shown.

[0415] The MU EDCA Parameter Group elements include Element ID (1 octet), Length (1 octet), Element ID Extension (1 octet), QoS Info (1 octet), MU AC_BE Parameter Record (3 octets), MU AC_BK Parameter Record (3 octets), MU AC_VI Parameter Record (3 octets), and MU AC_VO Parameter Record (3 octets).

[0416] The MU AC_BE Parameter Record (3 octets), the MU AC_BK Parameter Record (3 octets), the MU AC_VI Parameter Record (3 octets), and the MU AC_VO Parameter Record (3 octets) include an ACI / AIFSNF subfield (1 octet), an ECWmin / ECWmax subfield (1 octet), and a MU EDCA Timer subfield (1 octet), respectively.

[0417] The AIFSN recorded in the ACI / AIFSN subfield specifies the number of time slots taken after SIFS. This number of time slots is a fixed time before CSMA / CA implements random backoff. When this fixed time is made longer, access becomes difficult. Therefore, the AP MLD makes the AIFSN longer, making it difficult for the STA MLD to obtain access rights. The AIFSN can be adjusted either automatically or by user settings.

[0418] (Eighth Implementation Method)

[0419] AP MLD may also send a trigger frame to the STA of the STA MLD on both the main link and the sub-link on the STA MLD side that is in a non-STR link relationship with the main link according to the conditions based on the first embodiment, but may send the trigger frame simultaneously with or partially overlap with sending the trigger frame to the main link.

[0420] according to Fig.21 , the main link is Link1. Regarding the transmission of the trigger frame including the STA MLD as the transmission target to the main link Link1, when the STA MLD is not communicating, the AP MLD obtains the access right and transmits it. Repeating the period in which the trigger frame including the STA MLD as the transmission target is transmitted in the main link Link1, the AP MLD also transmits the trigger frame including the STA MLD as the transmission target in Link2, which is the sub-link. That is, when the AP MLD obtains the access right to the main link, if the sub-link is idle, the sub-link is also used at the same time, and the trigger frame including the STA MLD as the transmission target is transmitted in both links.

[0421] The method of obtaining the access right related to the transmission of the trigger frame is the same as that of the DL MU transmission in the first embodiment.

[0422] The end time of the trigger frame is made the same in the main link and the sub-link in such a way that the Trigger-Based PPDU (trigger-based PPDU) sent as UL MU starts simultaneously in the main link and the sub-link. In the case where the transmission of the trigger frame in the sub-link lags behind the transmission of the trigger frame in the main link, the PHY packet length is adjusted by setting padding bits in the trigger frame on the main link side so that the end time is the same. In addition, the Trigger-Based PPDU length indicated in the trigger frames sent in the two links is made the same so that the Trigger-Based PPDU in the two links ends at the same time. In addition, the Duration field values ​​of the two trigger frames (or the RTS frame when the access right is obtained before the trigger frame in the RTS frame, etc.) are made the same, so that the end time of the TXOP is the same. In the case where it is assumed that the end time of the TXOP of the main link ends earlier than that of the sub-link in the end, the TXOP of the sub-link also ends in such a way that the TXOP of the main link matches the end time or in a range with as little time difference as possible. A CF-End message can be sent to end the TXOP.

[0423] When a trigger frame is received in the main link and the sub-link and is sent at the same time, a response frame is synchronously sent from the AP MLD to the STA that sent the Trigger-Based PPDU in the main link and the sub-link after a fixed time (SIFS) of the Trigger-Based PPDU that ends at the same time. The response frames sent in the main link and the sub-link also have the same time length. This allows the sequence of frame exchange to continue synchronously in the main link and the sub-link. Therefore, the lower MAC processing units 36 and 38 in the AP MLD cooperate to perform collaboration related to the sent frame itself, the timing indicated in the sent frame, the packet length, and the TXOP length between AP1 on the Link1 side and AP2 on the Link2 side. In addition, when these response frames are sent at the end of the TXOP, the time length does not necessarily need to be the same. This is because interference occurs on the wireless link side where the TXOP ends prematurely due to the asynchronous termination of the TXOP during an extremely deviated period, and the CS does not function fully, but the impact is small.

[0424] (Ninth Implementation Method)

[0425] The purpose of this embodiment is the same as that of the fourth embodiment, etc. AP MLD classifies sub-links into two types of sub-links. AP MLD only allows STA MLDs whose main link and the sub-link are in a non-STR link relationship to use the first type of sub-link. AP MLD only allows STA MLDs whose main link and the sub-link are in a STR link relationship to use the second type of sub-link.

[0426] STA MLD uses an association request frame to notify AP MLD of a combination of available links and links in a non-STR relationship among them, and a combination of other links in a STR relationship (by notifying the combination of links in a non-STR relationship, it is known that the combination of links in a STR relationship is between other links, or conversely, by notifying the combination of links in a STR relationship, it is known that the combination of links in a non-STR relationship is between other links, so it may be either one). AP MLD uses an association response frame to notify STA MLD of available links for each STA MLD. For example, AP MLD uses Link1, Link2, and Link3 for multi-link communication, and uses Link2 as the main link. A certain STA MLD wants to use Link1, Link2, and Link3, and in addition, notifies AP MLD using an association request frame that Link2 and Link1 and Link2 and Link3 are in a non-STR link relationship. In this case, APMLD uses an association response frame to prohibit the STA MLD from using Link1. In other words, AP MLD prevents the STA MLD from using Link1. On the other hand, some other STA MLD wants to use Link1, Link2, and Link3, and notifies the AP MLD that all wireless links are in a STR link relationship using an association request frame. In this case, the AP MLD is not allowed to use Link3 using an association response frame. In other words, the AP MLD makes it impossible to use Link3 of the STA MLD. In this way, only the STA MLD whose main link and sub-link are in a non-STR relationship is allowed to use a certain sub-link, and only the STA MLD whose main link is in a STR relationship is allowed to use other sub-links. An example of a method in which the AP MLD notifies the STA MLD of such a restriction on the use of sub-links is to define a new value in the Status Code of the association response frame.

[0427] Fig.36An example of Status Code in the ninth embodiment is shown. A code such as "DENIED_STR_LINK" which means that the main link and the sub-link are rejected because they are in a STR link relationship is assigned to any value among the currently reserved values, here 20. That is, the case where the Status Code such as "DENIED_STR_LINK" is notified is the case where an association request frame is sent from a STA MLD in a STR link relationship between the sub-link and the main link when a rule is determined that only STA MLDs in a non-STR link relationship between the sub-link and the main link use the sub-link.

[0428] Furthermore, a code such as "DENIED_NON-STR_LINK" which means rejection because the main link and the sub-link are in a non-STR link relationship is assigned to any value among the currently reserved values, in this case 21. That is, the case where the Status Code "DENIED_NON-STR_LINK" is notified is the case where an association request frame is sent from the STA MLD in a non-STR link relationship between the sub-link and the main link when the rule of using the sub-link is determined so that only the STA MLD in a STR link relationship between the sub-link and the main link is used.

[0429] Alternatively, the existence of such limitation due to the secondary link may be notified in advance in the AP MLD using a beacon frame, a probe response frame, etc. This can avoid the inefficiency of not being allowed to connect when making a connection request without knowing the use policy of the secondary link.

[0430] In this way, STA MLDs in a non-STR relationship with the main link are aggregated only for a specific sub-link, so that the AP MLD only needs to check the communication status of the main link to pay attention to the non-STR relationship when accessing the specific sub-link, thereby simplifying the process of obtaining access rights.

[0431] (10th embodiment)

[0432] In the above embodiment, the AP MLD independently sets the main link in advance. In this embodiment, the AP MLD sets the main link according to the request from the STA MLD. In the case where the main link requested for each STA MLD is different, the AP MLD can also set a different main link for each STA MLD.

[0433] As described above, AP MLD uses the Reduced Neighbor Report element of the beacon frame to notify STA MLD of the wireless links that can be used in multilink communication in a certain wireless link. STA MLD uses the ML element of the association request frame to notify AP MLD of other wireless links for connection request and the desired main link using a certain wireless link.

[0434] AP MLD determines the link to be used and the main link, and notifies the decision result to STAMLD using the association response frame. When determining the main link, AP MLD can reject the connection request of the wireless link of the STA MLD that does not meet the constraint conditions. AP MLD defines a new value in the Status Code of the association response frame and notifies the STA MLD of the reason for rejecting the connection request.

[0435] Fig.37 An example of Status Code in the tenth embodiment is shown. A code such as "DENIED_NOT_RESTRICTION_CONDITION" which means rejection because the constraint condition is not satisfied is assigned to any value among the currently reserved values, in this case 9.

[0436] When AP MLD sets different main links according to the request of STA MLD, the number of main links may increase too much. In order to suppress the increase in the number of main links, AP MLD may also determine the main link by minimizing the number of main links for non-STR MLD, for example, setting it to 1 or 2, and sometimes reject the connection request of STA MLD depending on the situation.

[0437] According to the tenth embodiment, although the processing load on the AP MLD side increases, the STA MLD side has a great advantage because it can execute multilink communication in accordance with its own request.

[0438] (11th embodiment)

[0439] This embodiment corresponds to a case where the AP MLD changes the frequency of a part of the radio links of a plurality of radio links used in multi-link communication.

[0440] In wireless LANs that comply with the 802.11 standard, a channel switching mechanism is provided to change the channel used in the BSS to another channel. For example, when a radar wave is detected in the currently used channel during the Dynamic Frequency Selection (hereinafter referred to as DFS) operation, the currently used communication channel must be transferred to another channel.

[0441] In addition, AP MLD may change the frequency channel according to some algorithm. For example, AP MLD may change the frequency channel when there is some interference from other BSSs, etc., making it difficult to obtain access rights, or when QoS cannot be satisfied even if access rights are obtained.

[0442] In the previous channel switching, the STA MLD accommodated (connected) at a certain frequency, that is, the STA MLD that links the connection relationship, can be accommodated without going through the re-association process even if it is the channel of the transfer destination directly. However, when the frequency of the wireless link used in the multi-link is changed, the relationship between the wireless link and the main link may change from the relationship of the STR link to the relationship of the non-STR link or vice versa due to the STA MLD.

[0443] Therefore, when the frequency of a wireless link used by the AP MLD in the multi-link is changed, the STA MLD needs to notify the APMLD that the wireless link of the transfer destination has become a non-STR / STR link with the main link.

[0444] For example, after changing the wireless link, the AP MLD needs to collect information from the STA MLD that can identify from the STA MLD that the changed wireless link has become a non-STR / STR link with the main link. Therefore, the AP MLD creates a new type of trigger frame requesting the transmission of this information. The Common Info field of the trigger frame includes the Trigger Type subfield.

[0445] Fig.38 An example of the relationship between the value of the Trigger Type subfield and the type of trigger frame is shown. For example, the value of the Trigger Type subfield is 0 to 15. For example, the value 0 is the basic type (Basic). The value 1 indicates the type of beamforming report requested (Beamforming Report Poll (BRP)). Similarly, the following values ​​up to 7 respectively indicate the type of the current trigger frame. Values ​​8 to 15 are currently unused Reserved values.

[0446] A new trigger frame type requesting the transmission of information that can identify the relationship between non-STR / STR links is assigned to any value in the Reserved value. For example, it is defined so that a value of 8 indicates a type requesting link information (Link Info Report Poll (LIRP)).

[0447] Multiple (including a single) STA MLDs that receive the new type of trigger frame from the AP MLD in a certain wireless link create a frame containing information that can identify that the wireless link of the transfer destination has become a non-STR / STR link with the main link, and perform UL MU transmission to the AP MLD. As a result, the AP MLD can efficiently collect information that can identify that the changed wireless link has become a non-STR / STR link with the main link from the STA MLD.

[0448] The STA MLD may also set the information of the wireless link of the transfer destination (channel information, channel width, etc.) in the Trigger Dependent Common Info subframe to perform UL MU transmission.

[0449] When STA MLD obtains information about the wireless link of the transfer destination from AP MLD in advance, it can notify AP MLD of the relationship between the wireless link of the transfer destination and the non-STR / STR link of the main link. In order to achieve this, APMLD may also notify STA MLD of the change information indicating the change of the wireless link multiple times in advance, similar to the action in channel switching, and give STA MLD a time margin for re-notification. Specifically, beacon frames may also be used to notify the change information from multiple beacon intervals ago. In addition, AP MLD may also notify STA MLD of when the wireless link will be changed in the future, and give STA MLD a time margin for transferring to the new wireless link after the change. Specifically, STA MLD may also be notified that the frequency of the wireless link has changed from the beacon interval after a few cycles.

[0450] AP MLD sometimes adds a new wireless link corresponding to multi-link communication, but in this case, STAMLD needs to notify APMLD that the newly added wireless link and the main link become non-STR / STR links, so it needs to know when the newly added wireless link can be used.

[0451] When the AP MLD changes the main link itself, the relationship with other wireless links may also change. Therefore, the STA MLD needs to notify the AP MLD of the relationship between the main link after the AP MLD changes and the non-STR / STR link of other wireless links.

[0452] According to the eleventh embodiment, even when the AP MLD changes the frequency of a part of the plurality of radio links used in the multi-link communication, the multi-link communication can be continued.

[0453] (12th embodiment)

[0454] This embodiment corresponds to the case where the STA MLD changes the wireless link used in multi-link communication. After the STAMLD is associated with the AP MLD, it is sometimes desired to change the wireless link used. After the wireless link is changed, the STAMLD does not need to associate with the AP MLD again.

[0455] An example of wireless link switching performed by STA MLD is that STA MLD changes a wireless link that is in a STR link relationship with the main link to a wireless link that is in a non-STR link relationship with the main link. STA MLD may not be able to use a wireless link that is in a STR link relationship with the main link due to interference from other systems, etc. In this case, STA MLD may forcibly change a wireless link that is in a STR link relationship with the main link to a wireless link that is in a non-STR link relationship with the main link.

[0456] For example, if it is a 2.4GHz band, in addition to interference from other BSSs in the same wireless LAN, there is also interference from Bluetooth waves, electromagnetic waves from microwave ovens, etc. In such a case, the STA MLD is in a situation where, for example, the main link is in the 5GHz band, and a wireless link that is a candidate for another secondary link and has a non-STR relationship with the main link can be changed to the secondary link candidate when another 5GHz band is used. Therefore, the STA MLD needs to notify the AP MLD that the wireless link of the transfer destination is in a non-STR link relationship with the main link.

[0457] Another example of changing a wireless link by the STA MLD is that the STA MLD changes a secondary link that is in a non-STR link relationship with the main link to another wireless link. In this case, the main link and the secondary link may remain in a non-STR link relationship or may change to a STR link relationship.

[0458] In short, when the STA MLD changes the wireless link, it needs to notify the AP MLD that the new wireless link and the main link have a non-STR / STR link relationship. However, the relationship between other wireless links that have not been changed and the main link does not change, so the STA MLD does not need to re-notify the information related to the unchanged wireless links. If the relationship with other wireless links starting from the new wireless link becomes a non-STR link relationship, the STA MLD can also notify the AP MLD.

[0459] Another example of a change in a wireless link by a STA MLD is when the STA MLD changes a wireless link that was originally a main link to another wireless link. In this case, when the AP MLD sets the main link, the STAMLD does not use the main link, so it must select a wireless link that has a relationship with all other wireless links that becomes an STR link. To ensure this, the STA MLD may also omit the information on the relationship between non-STR / STR links in the change notification to the AP MLD.

[0460] When the primary link is determined by negotiation between the AP MLD and the STA MLD, the constraint condition is not necessary, so the STA MLD notifies the AP MLD again of the relationship between the wireless links to be reused. The primary link is determined by re-negotiation between the AP MLD and the STA MLD.

[0461] Sometimes STA MLD also adds a new corresponding wireless link. For example, sometimes a wireless link that has been set as a wireless link that AP MLD can use is added later and the STA MLD was not notified of its use during the association process. In such a case, STA MLD also notifies AP MLD that the newly added wireless link and other wireless links (especially the main link) have become non-STR / STR links.

[0462] In any of the above cases, the STA MLD can also identify the period when the wireless link is changed or added between the STA MLD and the AP MLD. In the case where the AP MLD needs to understand the relationship of the non-STR link, the APMLD also needs to understand the period. In addition, as a frame for notifying information related to these changes or new additions, the newly defined Link Change Indication action frame can be used. This action frame can also be used as Fig.11 , Figure 13 to Figure 16 The ML elements shown are used to notify information.

[0463] Furthermore, when the relationship of the non-STR link with respect to the main link does not change between the original wireless link and the wireless link after the change, notification of the non-STR / STR link relationship of the link from the STA MLD to the AP MLD may be omitted.

[0464] Even if STA MLD has notified AP MLD of the non-STR / STR link relationships of all possible candidate wireless links under AP MLD in the past, it is sometimes better for STA MLD to re-notify AP MLD of the non-STR / STR link relationships of all possible candidate wireless links. This is because if STA MLD does not actually use (for example, there is a wireless link assigned to a traffic ID (Traffic ID; hereinafter referred to as TID) that is not used), AP MLD may not retain currently unnecessary information because it wants to reduce the amount of information to be managed as much as possible.

[0465] According to the twelfth embodiment, even when the STA MLD changes the frequency of a part of the plurality of radio links used in the multi-link communication, the multi-link communication can be continued.

[0466] (13th embodiment)

[0467] There is direct link communication in which a first STA and a second STA associated with the same AP in a BSS (infrastructure BSS) configured under the AP directly communicate with each other without going through the AP.

[0468] exist Fig.21 In the case of AP MLD determining whether communication in the main link is possible, if the premise is that AP MLD intervenes, when confirming the other party of the terminal that AP MLD sends or receives in the main link, it can confirm whether the other party terminal is a non-STR terminal. However, in direct link communication, AP MLD strictly speaking does not intervene in frame exchange for the AP corresponding to the corresponding wireless link in AP MLD. Therefore, AP MLD must also observe frames other than frames sent or received by itself. That is, AP MLD must also confirm RA and TA for frames other than frames sent or received by itself to confirm whether it is a non-STR terminal.

[0469] As an example of a countermeasure, when direct link communication is performed, the use of multi-link communication is prohibited. For example, it is prohibited as a standard. As a method of prohibition, there are STA MLD autonomously restricting in a way that STA MLD does not perform direct link communication when multi-link communication is performed under a certain AP MLD, and AP MLD uses a beacon frame to prohibit direct link communication. It is also possible to newly define an information element for notifying prohibition (for example, called an EHT Operation element). According to the current wireless LAN standard, HT Operation elements, VHT Operation elements, HE Operation elements, etc. are defined. These Operation elements are used for AP to notify BSS of action associations. The new EHT Operation element is also used for AP to notify BSS of action associations. In addition, the EHTCapability element is used for terminals (including both AP and STA) to notify the capabilities of the terminal, which is different from the EHTOperation element.

[0470] If this is done, it is possible to simplify the AP MLD's judgment on whether the STA MLD is communicating in a wireless link that is in a non-STR link relationship with the main link. That is, the AP MLD only needs to confirm the other terminal (TA of the frame addressed to the AP MLD or RA of the frame sent from the AP MLD) that has communicated with this device in the main link.

[0471] On the other hand, multi-link communication can also be used in direct link communication. In this case, the STA MLD performs the same confirmation as the AP MLD for the destination STA MLD. That is, when multi-link communication is performed between STA MLDs, the STA MLD understands that the multiple wireless links that are the objects of multi-link communication are in a non-STR / STR link relationship.

[0472] In the case of TDLS in which the AP MLD does not directly participate in the setting of direct link communication, when the STA of the first STA MLD of the two STA MLDs performing direct link communication sends a TDLS setup request (TDLS SetupRequest) frame for setting startup, for example, information related to the multiple wireless links used is set in the TDLS setup request frame, and is sent to the STA of the second STA MLD of the two STA MLDs performing direct link communication via the APMLD. The STA of the second STA MLD that receives the TDLS setup request frame via the AP MLD sends a TDLS setup response (TDLS Setup Response) frame to the STA of the first STA MLD via the AP MLD. When the STA of the second STA MLD accepts a connection request for direct link communication, for example, information that can identify that the multiple wireless links are in a non-STR / STR link relationship is set in the TDLS setup response frame, and notifies the STA of the first STA MLD via the AP MLD. In addition, when direct link communication is in progress and multi-link communication is performed, the main link follows the setting of the AP MLD. The main link is made to follow the AP MLD in order to ensure that the transmission of the desired STA MLD can be determined by observing the main link by the APMLD. In addition, a partial set of wireless links used by the AP MLD can be basically selected. In addition, the first STA MLD that sends the TDLS establishment request frame is in a STR relationship between all selected wireless links, and should act like the AP MLD in the first embodiment. If there is a wireless link that is in a non-STR relationship with the main link, the first STA MLD also needs to set information related to the non-STR / STR link in the TDLS establishment request frame. Alternatively, as long as the two STA MLDs of the direct link must obtain access rights in the main link, and the use is limited to the case where other sub-links can be sent synchronously with it, there is no need to notify each other of the relationship of non-STR / STR links on the premise that all other sub-links are in a non-STR relationship with respect to the main link in the two STA MLDs. Specific examples of these notifications can follow the notification method in the first embodiment. That is, the same information element as the beacon frame can be set in the TDLS establishment request frame, and the same information element as the association request frame can be set in the TDLS establishment response frame for notification.

[0473] Traditional AP MLD can understand data frames, but cannot understand management frames such as TDLS setup request frames and TDLS setup response frames. Therefore, in order to prevent traditional AP MLD from participating in the setting of direct link communication, management frames such as TDLS setup request frames and TDLS setup response frames are encapsulated into data frames and sent. Encapsulation means setting the entire management frame in the Frame Body of the data frame as a data frame.

[0474] When direct link communication is performed between the first STA MLD and the second STA, the STA MLDs cannot transmit frames to each other before the direct link communication is set. Therefore, the first STA MLD encapsulates the management frame and transmits it to the traditional AP MLD. In the management frame, the address of the first STA MLD is set as the transmission source, and the address of the second STA MLD is set as the transmission destination.

[0475] The conventional AP MLD extracts the management frame from the Frame Body of the received data frame, encapsulates the management frame into a data frame, and sends the data frame to the second STA MLD which is the sending destination of the management frame.

[0476] The second STA MLD extracts the management frame from the Frame Body of the received data frame. In the management frame, the address of the first STA MLD is set as the transmission source, so the second STA MLD sets up direct link communication with the first STA MLD.

[0477] In the first embodiment, the AP MLD notifies the STA MLD of the information of the wireless links that can be used, and the STA MLD notifies the AP MLD of the wireless links that are used. In this embodiment, the wireless links used in direct link communication may be notified from the first STA MLD of the two STA MLDs performing direct link communication to the second STA MLD using a TDLS establishment request frame, and the relationship of the non-STR / STR links may be notified from the second STA MLD to the first STA MLD using a TDLS establishment response frame. In addition, the relationship of the non-STR / STR links may not be notified from the second STA MLD to the first STA MLD. Furthermore, the relationship of the non-STR / STR links may be notified from the first STA MLD to the second STA MLD.

[0478] The AP MLD uses a beacon frame to notify each STA MLD of the available wireless links. Therefore, each STA MLD can grasp the detailed information of each wireless link through the notification from the AP MLD, so it is not necessary to repeat it and send it to the other destination for direct link communication. Between the STA MLDs performing direct link communication, information about each wireless link can be exchanged with each other using link identifiers.

[0479] When direct link communication is performed using a wireless link (off-channel) not used by the AP MLD, information such as the frequency position of the wireless link used for direct link communication needs to be notified between STA MLDs performing direct link communication as notified by the AP MLD.

[0480] When AP MLD participates in the setting of direct link communication without participating in TDLS, AP MLD has the capability to understand the relationship between non-STR / STR links of two STA MLDs that set up direct link communication. Therefore, when each STA MLD sends the setting information for direct link communication, even if the information of the wireless link in the relationship between non-STR / STR links is not set in the management frame, APMLD can supplement the information and notify both STA MLDs that set up direct link communication.

[0481] As long as AP MLD confirms the TA or RA of the frame sent on the main link (regardless of whether AP MLD sends), it can also understand whether the desired STA MLD is communicating in the main link when direct link communications are mixed in the BSS.

[0482] According to the thirteenth embodiment, direct link communication can also be performed during multi-link communication.

[0483] (14th embodiment)

[0484] In the above-mentioned embodiment, the AP MLD sets the main link independently, or the AP MLD sets the main link through negotiation between the AP MLD and the STAMLD. In this embodiment, when the STA MLD obtains access to one of the multiple wireless links used in multi-link communication, that is, obtains TXOP and starts data exchange, it sets the wireless link to which it has access as the main link. The AP MLD agrees with the action of the main link determined by the STA MLD.

[0485] For example, when performing multilink communication using Link 1 and Link 2, when STA MLD obtains access right to Link 1 first, it sets Link 1 as the main link and transmits frames only in Link 1. When STA MLD follows Link 1 and obtains access right to Link 2, it also transmits frames in Link 2.

[0486] When transmitting a frame to the STA MLD, the AP MLD determines whether communication is not performed in all wireless links that are non-STR links in the STA MLD, and transmits the frame in one wireless link or multiple wireless links if communication is not performed.

[0487] To achieve this, the STA MLD needs to notify the AP MLD in advance of the relationship between non-STR / STR links between the wireless links to be used. The AP MLD understands this relationship for each STA MLD.

[0488] By doing so, the confirmation load in the AP MLD increases, but on the other hand, it is possible to increase the transmission opportunities in the STA MLD that has a wireless link that is a non-STR link relationship with the AP MLD. Here, such a STA MLD is set as a non-STR STA MLD. However, if the AP MLD limits the number of wireless links that are a non-STR link relationship among non-STR STA MLDs, the number of wireless links that the AP MLD should confirm can be reduced. This is not the case with wireless links that are in a STR link relationship.

[0489] In the 14th embodiment, when the non-STR STA MLD first obtains access rights in any wireless link that has become a non-STR link relationship, the AP MLD uses it as the main link. The AP MLD at least observes the communication status of all wireless links that the non-STR STAMLD notifies that it has become a non-STR link relationship, gradually grasps the main link of the non-STR STA MLD, and stops sending to the non-STR STA MLD in other wireless links that have become non-STR relationships with the main link. In the 14th embodiment, the notification of the main link based on the beacon frame of the first embodiment is not required.

[0490] According to the fourteenth embodiment, although the confirmation load in the AP MLD increases, the transmission opportunities of the STA MLD having a wireless link that is a non-STR link relationship with the AP MLD increase.

[0491] (15th embodiment)

[0492] In the description of the above embodiments, the antenna is not described. As a fifteenth embodiment, a method for mounting an antenna is described. This mounting method can be applied to all the above embodiments.

[0493] Fig.39 A first implementation example is shown in which the AP MLD 22 (or the STA MLD 24A, the STA MLD 24B) uses the first transmitting antenna 114 , the first receiving antenna 118 , the second transmitting antenna 124 , and the second receiving antenna 128 .

[0494] In the fifteenth embodiment, the AP MLD22 (or the STA MLD24A, STA MLD24B) is Figure 2 The structure is additionally provided with a first analog processing unit (ANA1) 33 and a second analog processing unit (ANA2) 35.

[0495] The first transmitting antenna 114 is connected to the first transmitting antenna connector 112 of the AP MLD 22. The first receiving antenna 118 is connected to the first receiving antenna connector 116 of the AP MLD 22. The second transmitting antenna 124 is connected to the second transmitting antenna connector 122 of the AP MLD 22. The second receiving antenna 128 is connected to the second receiving antenna connector 126 of the AP MLD 22.

[0496] The first analog processing unit (ANA1) 33 is connected to the first physical processing unit 32. The second analog processing unit (ANA2) 35 is connected to the second physical processing unit 34. The analog processing units 33 and 35 include a transmission system processing unit and a reception system processing unit, respectively.

[0497] The transmission system processing units of the analog processing units 33 and 35 convert the PHY packets, which are digital signals output from the physical processing units 32 and 34, into analog signals of a frequency corresponding to the wireless link. The analog signal output from the transmission system processing unit of the first analog processing unit 33 is supplied to the first transmission antenna 114 via the first transmission antenna connector 112 and transmitted from the antenna 114. The analog signal output from the transmission system processing unit of the second analog processing unit 33 is supplied to the second transmission antenna 124 via the second transmission antenna connector 122 and transmitted from the antenna 124.

[0498] The analog signal received by the first receiving antenna 118 is input to the receiving system processing unit of the first analog processing unit 33 via the first receiving antenna connector 116. The analog signal received by the second receiving antenna 128 is input to the receiving system processing unit of the second analog processing unit 33 via the second receiving antenna connector 126. The receiving system processing units of the analog processing units 33 and 35 convert the analog signals received by the receiving antennas 118 and 128 into digital signals in a manner that can be processed by the physical processing units 32 and 34.

[0499] Thus, in the first installation example, the first transmitting antenna 114 is used for transmitting Link 1, the first receiving antenna 118 is used for receiving Link 1, the second transmitting antenna 124 is used for transmitting Link 2, and the second receiving antenna 128 is used for receiving Link 2.

[0500] Fig.40 A second implementation example in which the AP MLD 22 (or the STA MLD 24A, STA MLD 24B) uses the first transceiver antenna 102 and the second transceiver antenna 104 is shown.

[0501] The first transceiver antenna 102 is connected to the first transceiver antenna connector 98 of the AP MLD 22. The second transceiver antenna 104 is connected to the second transceiver antenna connector 100 of the AP MLD 22.

[0502] The analog signal output from the transmission system processing section of the first analog processing section 33 is supplied to the first transmission and reception antenna 102 via the selector 94 and the first transmission and reception antenna connector 98, and is transmitted from the antenna 102. The analog signal output from the transmission system processing section of the second analog processing section 35 is supplied to the second antenna 104 via the selector 96 and the second transmission and reception antenna connector 100, and is transmitted from the antenna 104.

[0503] The analog signal received by the first transceiver antenna 102 is input to the reception system processing section of the first analog processing section 33 via the first transceiver antenna connector 98 and the selector 94. The analog signal received by the second transceiver antenna 104 is input to the reception system processing section of the second analog processing section 35 via the second transceiver antenna connector 100 and the selector 96.

[0504] The selectors 94 and 96 are switched by controllers included in the analog processing units 33 and 35. The selector 94 is switched to switch between transmission of Link 1 and reception of Link 1. The selector 96 is switched to switch between transmission of Link 2 and reception of Link 2.

[0505] Thus, in the second implementation example, the first transceiver antenna 102 is used for transmission and reception of Link 1, and the second transceiver antenna 104 is used for transmission and reception of Link 2.

[0506] Fig.41 A third implementation example in which the AP MLD 22 (or the STA MLD 24A, the STA MLD 24B) uses one transmission antenna 90 and one reception antenna 92 ​​is shown.

[0507] The transmission antenna 90 is connected to the transmission antenna connector 86 of the AP MLD 22. The reception antenna 92 ​​is connected to the reception antenna connector 88 of the AP MLD 22.

[0508] The analog signal output from the transmission system processing unit of the first analog processing unit 33 and the analog signal output from the transmission system processing unit of the second analog processing unit 35 are supplied to the multiplexing (MUX) circuit 82. The multiplexing circuit 82 multiplexes the two analog signals into a single analog signal. The output analog signal of the multiplexing circuit 82 is supplied to the transmission antenna 90 via the transmission antenna connector 86 and is transmitted from the antenna 90.

[0509] The analog signal received by the receiving antenna 92 ​​is input to the separation (DEMUX) circuit 84 via the receiving antenna connector 88. The separation circuit 84 separates the received signal according to the link frequency, supplies the received signal of Link 1 to the receiving system processing unit of the first analog processing unit 33, and supplies the received signal of Link 2 to the receiving system processing unit of the second analog processing unit 35.

[0510] Thus, in the third implementation example, the single transmitting antenna 90 is used for both the transmission of Link 1 and the transmission of Link 2, and the single receiving antenna 92 ​​is used for both the reception of Link 1 and the reception of Link 2.

[0511] Fig.42 The fourth installation example in which the AP MLD 22 (or the STA MLD 24A, STA MLD 24B) uses a single transceiver antenna 80 is shown. The transceiver antenna 80 is connected to the transceiver antenna connector 78 of the AP MLD 22.

[0512] In the fourth installation example, a selector 76 is added to the third installation example.

[0513] The output of the multiplexing circuit 82 is supplied to the transceiver antenna 80 via the selector 76 and the transceiver antenna connector 78 , and is transmitted from the antenna 80 .

[0514] The analog signal received by the transceiver antenna 80 is input to a separation (DEMUX) circuit 84 via the transceiver antenna connector 78 and the selector 76 .

[0515] The selector 76 is switched by the controller included in each of the analog processing units 33 and 35. The selector 76 is switched so as to switch between transmission of Link 1 and Link 2 and reception of Link 1 and Link 2.

[0516] Thus, in the fourth installation example, the single transmitting antenna 90 is used for both transmission and reception of Link 1 and Link 2.

[0517] Furthermore, the above-mentioned embodiments can be summarized into the following technical solutions.

[0518] Technical Solution 1

[0519] A wireless communication device, wherein:

[0520] The wireless communication device receives, from another wireless communication device at a first frequency, first information capable of identifying that the other wireless communication device can operate at a second frequency, and second information capable of identifying that there is a restriction on transmission and reception between the second frequency and the first frequency by the other wireless communication device,

[0521] notifying the other wireless communication device that either the first frequency or the second frequency is set as the primary frequency,

[0522] connecting with the other wireless communication device at the first frequency and the second frequency,

[0523] When the second information is received, access rights to frames addressed to the other wireless communication device at a secondary frequency other than the primary frequency among the first frequency or the second frequency are obtained based on whether the destination address or the source address of the communication via the primary frequency includes the address of the other wireless communication device.

[0524] Technical Solution 2

[0525] According to the wireless communication device described in technical solution 1,

[0526] The second information can identify that when transmission is performed at the second frequency, reception cannot be performed at the first frequency, or that when transmission is performed at the first frequency, reception cannot be performed at the second frequency.

[0527] Technical Solution 3

[0528] According to the wireless communication device described in technical solution 1,

[0529] When a transmission destination address or a transmission source address of communication via the primary frequency includes the address of the other wireless communication device, transmission of a frame addressed to the other wireless communication device at the secondary frequency is postponed.

[0530] Technical Solution 4

[0531] A wireless communication device, wherein:

[0532] The wireless communication device transmits, at the first frequency, third information capable of identifying that the device can operate at the second frequency and fourth information capable of identifying that there is a restriction on transmission and reception between the first frequency and the second frequency to other wireless communication devices.

[0533] receiving a notification from the other wireless communication device that either the first frequency or the second frequency is set as a primary frequency,

[0534] connecting with the other wireless communication device at the first frequency and the second frequency,

[0535] In the case where there are restrictions on transmission and reception between the first frequency and the second frequency, after obtaining access rights to the other wireless communication devices at the primary frequency, access rights to the other wireless communication devices at a secondary frequency other than the primary frequency among the first frequency or the second frequency are obtained.

[0536] Technical Solution 5

[0537] According to the wireless communication device described in technical solution 4,

[0538] When a transmission destination address or a transmission source address of communication via the primary frequency includes the address of the other wireless communication device, transmission of a frame addressed to the other wireless communication device at the secondary frequency is postponed.

[0539] Technical Solution 6

[0540] According to the wireless communication device described in technical solution 5,

[0541] When the transmission of the frame for which the access right is obtained at the primary frequency is delayed, the transmission of the frame for which the access right is obtained at the secondary frequency is delayed.

[0542] Technical Solution 7

[0543] According to the wireless communication device described in technical solution 1,

[0544] The first information can further identify that the other wireless communication device can operate at the second frequency and the third frequency.

[0545] The wireless communication device notifies the other wireless communication device that any one of the first frequency, the second frequency, or the third frequency is set as the primary frequency,

[0546] Two frequencies other than the primary frequency among the first frequency, the second frequency, or the third frequency are the secondary frequencies.

[0547] Technical Solution 8

[0548] According to the wireless communication device described in technical solution 4,

[0549] The third information can also identify that the device can operate at the second frequency and the third frequency.

[0550] the wireless communication device receiving the notification that any one of the first frequency, the second frequency, or the third frequency is set as the primary frequency from the other wireless communication device,

[0551] Two frequencies other than the primary frequency among the first frequency, the second frequency, or the third frequency are the secondary frequencies.

[0552] Technical Solution 9

[0553] The wireless communication device according to claim 1 or 4 further comprises:

[0554] A first connector connected to a first antenna for transmitting a signal of the first frequency;

[0555] A second connector connected to a second antenna for receiving a signal of the first frequency;

[0556] a third connector to which a third antenna for transmitting a signal of the second frequency is connected; and

[0557] A fourth antenna for receiving a signal of the second frequency is connected to the fourth connector.

[0558] Technical Solution 10

[0559] The wireless communication device according to claim 1 or 4 further comprises:

[0560] a first connector to which a first antenna for transmitting and receiving signals of the first frequency is connected; and

[0561] A second antenna for transmitting and receiving a signal of the second frequency is connected to the second connector.

[0562] Technical Solution 11

[0563] The wireless communication device according to claim 1 or 4 further comprises:

[0564] a first connector to which a first antenna for transmitting a signal of the first frequency and a signal of the second frequency is connected; and

[0565] A second antenna for receiving the signal of the first frequency and the signal of the second frequency is connected to the second connector.

[0566] Technical Solution 12

[0567] According to the wireless communication device described in technical solution 1 or technical solution 4,

[0568] The wireless communication device further includes a connector to which is connected an antenna for transmitting the signal of the first frequency and the signal of the second frequency and receiving the signal of the first frequency and the signal of the second frequency.

[0569] Technical Solution 13

[0570] A wireless communication method is a wireless communication method of a first wireless communication device connected to a second wireless communication device, wherein:

[0571] receiving, from the second wireless communication device at the first frequency, first information capable of identifying that the second wireless communication device can operate at the second frequency and second information capable of identifying that there is a restriction on transmission and reception between the second frequency and the first frequency by the second wireless communication device,

[0572] notifying the second wireless communication device that either the first frequency or the second frequency is set as a primary frequency,

[0573] connecting to the second wireless communication device at the first frequency and the second frequency,

[0574] When the second information is received, access rights to frames addressed to the second wireless communication device at a secondary frequency other than the primary frequency among the first frequency or the second frequency are obtained based on whether the destination address or the source address of the communication via the primary frequency includes the address of the second wireless communication device.

[0575] Technical Solution 14

[0576] A wireless communication method is a wireless communication method of a first wireless communication device connected to a second wireless communication device, wherein:

[0577] transmitting, at the first frequency, to the second wireless communication device third information capable of identifying that the operation can be performed at the second frequency and fourth information capable of identifying that there is a restriction on transmission and reception between the first frequency and the second frequency,

[0578] receiving a notification from the second wireless communication device that either the first frequency or the second frequency is set as a primary frequency,

[0579] connecting to the second wireless communication device at the first frequency and the second frequency,

[0580] In the case where there are restrictions on transmission and reception between the first frequency and the first frequency, after obtaining access rights to the second wireless communication device at the primary frequency, access rights to the second wireless communication device at a secondary frequency other than the primary frequency among the first frequency or the second frequency are obtained.

[0581] In addition, the present invention is not directly limited to the above-mentioned embodiments, and the constituent elements can be deformed and concretized in the implementation stage without departing from the scope of the gist thereof. In addition, various inventions can be generated by appropriate combinations of multiple constituent elements disclosed in the above-mentioned embodiments. For example, several constituent elements can also be deleted from all the constituent elements shown in the embodiments. Furthermore, constituent elements throughout different embodiments can also be appropriately combined.

Claims

1. A wireless communication device, configured to: receiving, from another wireless communication device at a first frequency, first information notifying that the other wireless communication device can operate at a second frequency, and second information indicating whether the other wireless communication device has restrictions on transmission and reception between the second frequency and the first frequency, notifying the other wireless communication device via a beacon frame that any one of the first frequency and the second frequency is set as the main frequency, connecting with the other wireless communication device at the first frequency and the second frequency, When the second information indicates that the other wireless communication device has restrictions on transmission and reception between the second frequency and the first frequency, the wireless communication device is configured to: determining whether the other wireless communication device is communicating at the main frequency based on whether a destination address or a source address of communication via the main frequency includes an address of the other wireless communication device, When the wireless communication device determines that the other wireless communication device is not communicating at the main frequency, the wireless communication device transmits a frame addressed to the other wireless communication device at a sub-frequency other than the main frequency among the first frequency and the second frequency.

2. The wireless communication device according to claim 1, wherein: The second information indicates whether reception cannot be performed at the first frequency when transmission is performed at the second frequency or whether reception cannot be performed at the second frequency when transmission is performed at the first frequency.

3. The wireless communication device according to claim 1, wherein: When a transmission destination address or a transmission source address of communication via the primary frequency includes the address of the other wireless communication device, transmission of a frame addressed to the other wireless communication device at the secondary frequency is postponed.

4. The wireless communication device according to claim 1, wherein: The first information can also notify the other wireless communication device that it can operate at the second frequency and the third frequency. The wireless communication device is configured to notify the other wireless communication device that any one of the first frequency, the second frequency, and the third frequency is set as the main frequency, Two frequencies other than the main frequency among the first frequency, the second frequency, and the third frequency are the sub-frequencies.

5. A wireless communication device, configured to: transmitting, at the first frequency, third information notifying that the wireless communication device can operate at the second frequency and fourth information indicating whether there is a restriction on transmission and reception between the first frequency and the second frequency to other wireless communication devices, receiving, from the other wireless communication device via a beacon frame, a notification that any one of the first frequency and the second frequency is set as a main frequency, connecting with the other wireless communication device at the first frequency and the second frequency, When the fourth information indicates that the wireless communication device has restrictions on transmission and reception between the first frequency and the second frequency, the wireless communication device is configured to: obtaining access rights to the other wireless communication devices at the primary frequency; and The access right to the other wireless communication device is obtained at a sub-frequency other than the main frequency among the first frequency and the second frequency.

6. The wireless communication device according to claim 5, wherein: When a transmission destination address or a transmission source address of communication via the primary frequency includes the address of the other wireless communication device, transmission of a frame addressed to the other wireless communication device at the secondary frequency is postponed.

7. The wireless communication device according to claim 6, wherein: When the transmission of the frame for which the access right is obtained at the primary frequency is delayed, the transmission of the frame for which the access right is obtained at the secondary frequency is delayed.

8. The wireless communication device according to claim 5, wherein: The third information can also identify that the device can operate at the second frequency and the third frequency. The wireless communication device is configured to receive the notification that any one of the first frequency, the second frequency, and the third frequency is set as the main frequency from the other wireless communication device, Two frequencies other than the main frequency among the first frequency, the second frequency, and the third frequency are the sub-frequencies.

9. The wireless communication device according to claim 1 or 5, wherein: Also available: A first connector connected to a first antenna for transmitting a signal of the first frequency; A second connector connected to a second antenna for receiving a signal of the first frequency; a third connector to which a third antenna for transmitting a signal of the second frequency is connected; and A fourth antenna for receiving a signal of the second frequency is connected to the fourth connector.

10. The wireless communication device according to claim 1 or 5, wherein: Also available: a first connector to which a first antenna for transmitting and receiving signals of the first frequency is connected; and A second antenna for transmitting and receiving a signal of the second frequency is connected to the second connector.

11. The wireless communication device according to claim 1 or 5, wherein: Also available: a first connector to which a first antenna for transmitting a signal of the first frequency and a signal of the second frequency is connected; and A second antenna for receiving the signal of the first frequency and the signal of the second frequency is connected to the second connector.

12. The wireless communication device according to claim 1 or 5, wherein: The wireless communication device further includes a connector to which is connected an antenna for transmitting the signal of the first frequency and the signal of the second frequency and receiving the signal of the first frequency and the signal of the second frequency.

13. A wireless communication method, comprising: a first wireless communication device connected to a second wireless communication device; The first wireless communication device is configured to receive, from the second wireless communication device at the first frequency, first information notifying that the second wireless communication device can operate at the second frequency and second information indicating whether there is a restriction on transmission and reception between the second frequency and the first frequency by the second wireless communication device, The wireless communication method comprises: notifying the second wireless communication device, via a beacon frame, that any one of the first frequency and the second frequency is set as a main frequency; connecting to the second wireless communication device at the first frequency and the second frequency; and In a case where the second information indicates that the second wireless communication device has restrictions on transmission and reception between the second frequency and the first frequency, the first wireless communication device is configured to: determine whether the second wireless communication device is communicating at the main frequency based on whether the destination address or the source address of the communication via the main frequency includes the address of the second wireless communication device, and when the first wireless communication device determines that the second wireless communication device is not communicating at the main frequency, send a frame addressed to the second wireless communication device at a sub-frequency other than the main frequency between the first frequency and the second frequency.

14. A wireless communication method, which is a wireless communication method of a first wireless communication device connected to a second wireless communication device, the wireless communication method comprising: transmitting, at the first frequency, to the second wireless communication device third information notifying that the first wireless communication device can operate at the second frequency and fourth information indicating whether there is a restriction on transmission and reception between the first frequency and the second frequency; receiving, from the second wireless communication device via a beacon frame, a notification that any one of the first frequency and the second frequency is set as a main frequency; connecting with the second wireless communication device at the first frequency and the second frequency; as well as When the fourth information indicates that the first wireless communication device has restrictions on transmission and reception between the first frequency and the second frequency: obtaining access rights to the second wireless communication device at the primary frequency; as well as The access right to the second wireless communication device is obtained at a sub-frequency other than the main frequency among the first frequency and the second frequency.

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