Communication control device

Abstract

[Problem] To provide a communication control device that does not limit multiple serving AP MLD mode to the operation of one link. [Solution] A communication control device according to the present disclosure comprises a control unit that controls communication by a first communication device, wherein the control unit is configured to control the first communication device to transmit, via a first communication path, a first signal to a second communication device that can communicate using a plurality of links at the same time, and to control the first communication device to transmit, via a second communication path or a third communication path, a second signal containing information pertaining to a transmission end time of the first signal to a third communication device that is to communicate with the first communication device.

Description

communication control device

[0001] An embodiment of the present invention relates to a communication control device.

[0002] Wireless communication using multiple links (also called MLO (Multi-link Operation)) is being considered as a method to meet the high transmission speed requirements of 8K transmission and XR (cross reality).

[0003] When performing multi-link operation, each link is selected from multiple independent wireless transmission paths divided, for example, in the frequency domain. For example, a channel selected from multiple channels included in one of the frequency bands, such as the 2.4 GHz band, 5 GHz band, 6 GHz band, or 920 MHz band, is used.

[0004] A device that supports MLO is called an MLD (Multi-link Device). An MLD is a logical entity that contains one or more STAs and has only one SAP (service access point) to a higher layer. An MLD in which each STA contained in the MLD is an AP is called an AP MLD, and an MLD in which each STA is a non-AP STA is called a non-AP MLD. Furthermore, to clearly indicate that each entity within an MLD is an entity within the MLD, it is written as an AP belonging to an AP MLD (AP affiliated with AP MLD) or a non-AP STA belonging to a non-AP MLD (non-AP STA affiliated with AP MLD).

[0005] Liwen Chu et al., “Smooth Roaming Follow Up”, IEEE 802.11-23 / 0632r1, April 2, 2023

[0006] Previous contributions have proposed Single Serving AP MLD mode, in which a Roaming MLD common MAC manages multiple AP MLDs and a non-AP MLD connects to only one of the AP MLDs, and Multiple Serving AP MLD mode, in which multiple links are established across multiple non-AP MLDs. Furthermore, within Multiple Serving AP MLD mode, Transit Multiple Serving AP MLD mode, which allows simultaneous connection to multiple AP MLDs only when roaming, and Non-transit Multiple Serving AP MLD mode, which allows simultaneous connection even when not roaming, have also been proposed. Among these, only methods have been proposed that limit NSTR operation in Non-transit Multiple Serving AP MLD mode to one link, which does not fully demonstrate the benefits of Multiple Serving AP MLD mode.

[0007] In view of these problems, the present disclosure provides a communication control device that does not limit the operation of Multiple Serving AP MLD mode to one link.

[0008] The communication control device of the present disclosure includes a control unit that controls communication of a first communication device, and the control unit is configured to control the first communication device to transmit a first signal to a second communication device that is capable of communicating using multiple links simultaneously via a first communication path, and to control the first communication device to transmit a second signal including information regarding the end time of transmission of the first signal to a third communication device that communicates with the first communication device via a second communication path or a third communication path.

[0009] 1 shows an example of the overall configuration of a wireless communication system in the first embodiment. FIG. 2 is a diagram illustrating a specific example of backhaul in the wireless communication system in the first embodiment. FIG. 3 is a block diagram of a communication device including a communication control device in the first embodiment. FIG. 4 is a block diagram of another communication device including a communication control device in the first embodiment. FIG. 5 shows an example of the overall configuration of a wireless communication system in a first comparative example. FIG. 6 shows an example of the overall configuration of a wireless communication system in a second comparative example. FIG. 7 is a diagram illustrating an example of a sequence when multi-link operation is performed in the second comparative example etc. FIG. 8 is an example of a flowchart when AP MLD1 and AP MLD2 perform multi-link operation in the first embodiment. FIG. 9 shows an example format of a frame of information specifying the transmission end time of a PPDU in the first embodiment. FIG. 10 is a diagram illustrating an example of a sequence when multi-link operation is performed in the first embodiment. FIG. 11 is a diagram illustrating an example of a format of a Multiple Serving Info Action (Request / Response / Confirm) frame in the first embodiment. FIG. 12 is a diagram illustrating an example of a sequence when multi-link operation is performed in the second embodiment. FIG. 13 is a diagram illustrating an example of a sequence when multi-link operation is performed in the third embodiment. FIG. 14 is a diagram illustrating an example of a sequence when multi-link operation is performed in the fourth embodiment. FIG. 15 is a diagram illustrating an example of a sequence when multi-link operation is performed in the fifth embodiment. FIG. 16 is a diagram illustrating an example of a sequence when multi-link operation is performed in the sixth embodiment. FIG. 13 is a diagram illustrating an example of a sequence when Multi-link operation is performed in the seventh embodiment. FIG. 14 is a block diagram illustrating an example of the hardware configuration of a computer that executes a series of processes according to the first to seventh embodiments by a program. FIG. 15 is a block diagram illustrating an example of the schematic configuration of a smartphone to which the first to seventh embodiments are applied. FIG. 16 is a block diagram illustrating an example of the schematic configuration of an in-vehicle device to which the first to seventh embodiments are applied.FIG. 1 is a block diagram showing an example of a schematic configuration of a wireless AP to which the first to seventh embodiments are applied.

[0010] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings. In this specification and the drawings, components having substantially the same functional configurations are designated by the same reference numerals, and their description will be omitted as appropriate. The drawings are simplified, and components necessary for implementation other than those shown in the drawings are also included as appropriate. Furthermore, when terms such as "first" and "second" are used in this specification or claims, unless otherwise specified, they do not represent any order or importance, but are used to distinguish one configuration from another.

[0011] Furthermore, in this disclosure, there are places where the terms "greater than" and "less than" are used, but these can be read as "greater than" and "less than" respectively.

[0012] FIG. 1 shows an example of the overall configuration of a wireless communication system according to the first embodiment.

[0013] 1 includes AP MLD1, AP MLD2, and Non-AP MLD 100. Furthermore, the wireless communication system of this embodiment takes an example in which AP MLDs 1 and 2 are used to communicate with a Non-AP MLD, but instead of AP MLDs 1 and 2, a configuration in which communication with a Non-AP MLD is possible is also possible in which two APs or AP MLDs that can establish only one link are used, or an AP MLD that can establish multiple links is combined with an AP or AP MLD that can establish one link.

[0014] In the following wireless communication system, the APs included in AP MLD1 are referred to as AP1-1 and AP1-2, the APs included in AP MLD2 are referred to as AP2-1 and AP2-2, and the STAs included in Non-AP MLD100 are referred to as STA1-1 and STA1-2.

[0015] AP MLDs 1 and 2 are communication devices equivalent to base stations that support MLO. Non-AP MLD 100 is a communication device equivalent to a terminal that supports MLO. Non-AP MLD 100 is connected to AP MLDs 1 and 2. In FIG. 1 , the solid line connecting AP MLD 1 and Non-AP MLD 100 and the dashed-dotted line connecting AP MLD 2 and Non-AP MLD 100 indicate that they are connected by different links. In this example, the link connecting AP MLD 1 and Non-AP MLD 100 (corresponding to the solid line in FIG. 1 ) is called link 1, and the link connecting AP MLD 2 and Non-AP MLD 100 (corresponding to the dashed line in FIG. 1 ) is called link 2.

[0016] A link refers to a physical path that can transmit MAC service data units (MSDUs) between STAs. Links formed between a certain STA and a different STA are treated as different links. For example, in the example of Figure 1, link 1 and link 2 are different links.

[0017] Furthermore, each AP in AP MLD 1 and each AP in AP MLD 2 are connected via a backhaul. In Fig. 1, link 1 is shown by a solid line, link 2 is shown by a dashed line, and the backhaul is shown by a dotted line.

[0018] Also, in this example, a Single Mobility Domain (SMD) AP MLD3, which is the management entity for AP1-1, AP1-2, AP2-1, and AP2-2, is connected to the backhaul. For example, the SMD AP MLD3 is used to establish communication between the AP MLD1 and AP MLD2. In this example, the SMD AP MLD3 is illustrated as existing independently outside the AP MLD1 and AP MLD2, but it may be included in the AP MLD1, AP MLD2, or another AP MLD.

[0019] The two links used in the wireless communication system of Fig. 1 may be two channels selected from the same frequency band, or may be two channels selected from different frequency bands. Furthermore, the number of links used between AP-MLD 1 or 2 and Non-AP MLD 100 is not limited to two, and communication may be performed using three or more links. Furthermore, the number of AP MLDs connected to Non-AP MLD 100 is not limited to two, and may be one, or three or more.

[0020] In addition to the operations described in this embodiment, the AP MLDs 1 and 2 and the Non-AP MLD 100 may also operate as a wireless LAN base station and terminal in accordance with the IEEE 802.11 standard, such as IEEE 802.11a / b / g / n / ac / ax / be / bn or their successor standards. For example, the AP MLDs 1 and 2 and the Non-AP MLD 100 may operate based on CSMA / CA (Carrier Sense Multiple Access with Carrier Avoidance) as the access method, and the AP MLDs 1 and 2 may transmit beacon signals at regular time intervals (periodically).

[0021] AP MLDs 1 and 2 and Non-AP MLD 100 have insufficient isolation within the device, causing inter-link interference in which signals between Link 1 and Link 2 interfere with each other within the device. For this reason, AP MLDs 1 and 2 and Non-AP MLD 100 cannot simultaneously transmit or receive on Link 1 and on Link 2. This type of MLD is called an NSTR (Non-Simultaneous TxRx) MLD. In this embodiment, these are AP MLDs 1 and 2 and Non-AP MLD 100.

[0022] Typically, the AP MLDs 1 and 2 and the Non-AP MLD 100 are known in advance, for example, during device design or manufacturing, and the AP MLDs 1 and 2 and the Non-AP MLD 100 may operate to suppress a decrease in communication efficiency on the assumption that their own devices are NSTR MLDs. For example, the AP MLDs 1 and 2 and the Non-AP MLD 100 may be configured so that when receiving on one link, they do not start transmitting on the other link. However, such a configuration is not necessary to realize this embodiment.

[0023] FIG. 2 is a diagram illustrating a specific example of a backhaul of the wireless communication system in the first embodiment.

[0024] In this example, the router 5 and each AP (here, AP1 and AP2) are connected by a wired backhaul. In other words, data to be transmitted to a terminal is transmitted from the router 5 to the AP connected to the terminal via a wired cable, and then wirelessly transmitted to the terminal. The wired communication in the backhaul may be Ethernet communication, or alternatively, for example, power line communications or optical communication using optical fiber. The backhaul is not limited to wired communication. For example, it may be wireless communication based on the IEEE 802.11 standard (using a band separate from the link) or cellular wireless communication such as 4G or 5G, as with a mobile router. Furthermore, in this example, if AP3 is not directly connected to the router 5 via a wired connection but receives data wirelessly via AP2, which is wired to the router 5, this wireless communication section is also referred to as the backhaul. The backhaul may also consist of multiple wired communications, multiple wireless communications, or a combination of these. If the backhaul has multiple possible means, one or more communication means may be selected based on the communication speeds of these means. For example, the communication means that can achieve the fastest communication speed may be selected.

[0025] [Configuration Example of AP MLDs 1 and 2] FIG. 3 is a block diagram of a communication device including a communication control device in the first embodiment.

[0026] The communication device (here, AP MLD1 will be taken up) mainly comprises a communication unit 110, a control unit 130, and a storage unit 140. AP MLD2 has a similar configuration, so here, AP MLD1 will be taken up for explanation. The communication unit 110 comprises a communication control unit 111, a communication storage unit 112, a common data processing unit 113, AP1, and AP2.

[0027] In the following, in this embodiment, the communication devices will be described as the AP MLDs 1 and 2 and the Non-AP MLD 100. The communication control device is, for example, a chip realized by one or more LSIs and including a communication unit 110.

[0028] AP1 and AP2 each include an individual data processing unit 121, a signal processing unit 122, a wireless interface unit 123, one or more amplifier units 124, and one or more antennas 150. In other words, each AP comprises a set of the individual data processing unit 121, the signal processing unit 122, the wireless interface unit 123, the amplifier unit 124, and the antenna 150, and two or more APs are components of a communication device. In AP MLD1, AP1 and AP2 correspond to AP1-1 and AP1-2, respectively, in FIG. 1. In addition, in AP MLD2, AP1 and AP2 correspond to AP2-1 and AP2-2, respectively, in FIG. 1.

[0029] AP1 performs processing related to link 1 within the AP MLD 100, and AP2 performs processing related to link 2 within the AP MLD 100. In particular, the set of the individual data processing unit 121 and the signal processing unit 122 in each AP is also referred to as an AP entity. Each AP performs communication on its respective link.

[0030] AP1 or its AP entity corresponds to the first wireless communication unit that performs communication regarding link 1 (first wireless communication), and AP2 or its AP entity corresponds to the second wireless communication unit that performs communication regarding link 2 (second wireless communication).

[0031] The communication control unit 111 controls the operation of each unit and the transmission of information between each unit. It also controls the transfer of control information and management information to be notified to other communication devices to the common data processing unit 113, AP1, AP2, and wired interface unit 160. The communication control unit 111 is also referred to as an MLD management entity. In this embodiment, the communication control unit 111 controls each unit so that information related to NSTR operation, such as information specifying the PPDU transmission end time, is exchanged between AP MLD1 and AP MLD2 as information for performing end time alignment. End time alignment will be described later.

[0032] The communication storage unit 112 stores information used by the communication control unit 111. The communication storage unit 112 also stores data to be transmitted to the non-AP MLD 100 and data received from the non-AP MLD 100.

[0033] In this example, the data processing unit is composed of an individual data processing unit 121 that performs operations necessary for communication in a single frequency band, and a common data processing unit 113 that is connected to multiple individual data processing units 121 and performs operations common to communication in multiple frequency bands.

[0034] During transmission, the common data processing unit 113 performs sequence management of the data stored in the communication storage unit 112 and the control information and management information received from the communication control unit 111, performs encryption processing, etc., and allocates the processed data to each individual data processing unit 121. During reception, the common data processing unit 113 performs data decryption processing and reordering processing.

[0035] During transmission, each individual data processing unit 121 performs channel access operation based on carrier sense, generates data units by adding a MAC (Media Access Control) header and an error detection code to the data to be transmitted, and performs processing to concatenate multiple data units. During reception, it performs processing to deconcatenate the MAC header of the received data unit, analyzes and detects errors, and requests retransmission.

[0036] The operations of the common data processing unit 113 and each individual data processing unit 121 are not limited to those described above, and for example, one may perform the operation of the other. The common data processing unit 113 is also called an Upper MAC, a Higher MAC, or an MLD entity, and the individual data processing unit 121 is also called a Lower MAC.

[0037] The signal processing unit 122 includes a transmission signal processing unit and a reception signal processing unit (not shown). The transmission signal processing unit performs encoding, interleaving, modulation, etc. on the data unit, adds a physical header, and generates a symbol stream. At this time, the transmission signal processing unit may perform spatial separation processing for MIMO (Multi-Input Multi-Output). However, each signal processing unit 122 may not perform spatial separation processing, but may instead apply an arbitrary delay amount (hereinafter referred to as cyclic shift delay (CSD)) to each antenna 150. The reception signal processing unit analyzes the physical header and performs demodulation, deinterleaving, decoding, etc. on the symbol stream to generate a data unit. Furthermore, each signal processing unit 122 estimates complex channel characteristics and performs spatial separation processing as necessary. The signal processing unit 122 is also referred to as a PHY unit.

[0038] The wireless interface unit 123 includes a transmitting wireless interface unit and a receiving wireless interface unit (not shown). The transmitting wireless interface unit performs digital-to-analog signal conversion, filtering, up-conversion, and phase control on the symbol stream to generate a transmission signal. The receiving wireless interface unit performs down-conversion, filtering, and analog-to-digital signal conversion on the received signal to generate a symbol stream.

[0039] The amplifier unit 124 of each AP amplifies a signal input from the wireless interface unit 123 or the antenna 150. A part of the amplifier unit 124 may be a component outside the communication unit 110. Alternatively, a part of the amplifier unit 124 may be included in the wireless interface unit 123.

[0040] The control unit 130 controls the communication unit 110 and the communication control unit 111. The control unit 130 may also perform some of the operations of the communication control unit 111. The communication control unit 111 and the control unit 130 may be configured as a single block. The control unit of the communication control device according to the present disclosure corresponds to the communication control unit 111, for example, or corresponds to at least one of the communication unit 110 and the communication control unit 111. The communication control device according to the present disclosure includes the communication control unit 111, for example, and may also include other components, for example, at least one of AP1 and AP2.

[0041] The storage unit 140 holds information used by the control unit 130 and the communication unit 110. The storage unit 140 may also perform part of the operations of the communication storage unit 112. The storage unit 140 and the communication storage unit 112 may be configured as a single block.

[0042] The wired interface unit 160 connects the communication device to a backhaul, which is a wired line. The communication device is also connected to another communication device (in this example, AP MLD2) via the backhaul so that they can communicate with each other. In this embodiment, information specifying the end time of PPDU transmission and the like are exchanged via the backhaul.

[0043] Furthermore, each AP may include a storage unit. In this embodiment, the frequencies (or frequency bands) of the links used by each AP are different, but the same case is not excluded.

[0044] The individual data processing unit 121 and the signal processing unit 122 may be configured as one set, and multiple sets may be connected to one wireless interface unit 123. In other words, one wireless interface unit 123 may be shared by multiple APs.

[0045] Furthermore, a configuration may be adopted in which a wireless interface unit 123, an amplifier unit 124, and an antenna 150 are grouped together, and multiple groups are connected to one signal processing unit 122. In other words, the signal processing unit 122 may be shared by multiple APs. In this case, there may be one or multiple individual data processing units 121.

[0046] The configuration of the communication unit 110 is an example and is not limited to this. For example, the communication unit 110 may be configured with three or more blocks. Furthermore, when the communication unit 110 is configured with three or more blocks, some of the blocks may share the same antenna via a frequency division unit (not shown).

[0047] [Configuration Example of Non-AP MLD 100] FIG. 4 is a block diagram of another communication device including the communication control device in the first embodiment.

[0048] The basic configuration of a communication device (here, Non-AP MLD 100 is taken up) is the same as that of AP MLD 1. Non-AP MLD 100 mainly comprises a communication unit 210, a control unit 230, and a storage unit 240. Communication unit 210 comprises a communication control unit 211, a communication storage unit 212, a common data processing unit 213, Non-AP STA1 (hereinafter referred to as STA1), and Non-AP STA2 (hereinafter referred to as STA2). Communication unit 210 can be realized by one or more LSIs.

[0049] STA1 and STA2 each include an individual data processing unit 221, a signal processing unit 222, a wireless interface unit 223, one or more amplifier units 224, and one or more antennas 250. In other words, each STA configures a Non-AP (STA) with the individual data processing unit 221, signal processing unit 222, wireless interface unit 223, amplifier unit 224, and antenna 250 as one set, and two or more Non-AP (STA)s are components of a communication device.

[0050] STA1 performs processing related to link 1 within Non-AP MLD 100, and STA2 performs processing related to link 2 within Non-AP MLD 100. In particular, the set of individual data processing unit 221 and signal processing unit 222 is also referred to as a non-AP STA entity. STA1 or its non-AP STA entity corresponds to a first wireless communication unit that performs communication related to link 1 (first wireless communication), and STA2 or its non-AP entity corresponds to a second wireless communication unit that performs communication related to link 2 (second wireless communication). STA1 and STA2 correspond to STA1-1 and STA1-2 in FIG. 1, respectively.

[0051] The communication control unit 211 controls the operation of each unit and the transmission of information between each unit. It also controls the transfer of control information and management information to be notified to other communication devices to the common data processing unit 213, STA1, and STA2. The communication control unit 211 is also called an MLD management entity.

[0052] The communication storage unit 212 stores information used by the communication control unit 211. The communication storage unit 212 also stores data to be transmitted to the AP MLDs 1 and 2 and data received from the AP MLDs 1 and 2.

[0053] During transmission, the common data processing unit 213 performs sequence management of the data stored in the communication storage unit 212 and the control information and management information received from the communication control unit 211, performs encryption processing, etc., and allocates the processed data to each individual data processing unit 221. During reception, the common data processing unit 213 performs data decryption processing and reordering processing.

[0054] During transmission, each individual data processing unit 221 performs channel access operations based on carrier sense, adds a Media Access Control (MAC) header to the data to be transmitted, adds an error detection code to generate a data unit, and performs processing to concatenate multiple data units. During reception, each individual data processing unit 221 performs processing to deconcatenate the MAC header of the received data unit, analyzes and detects errors, and requests retransmission.

[0055] The operations of the common data processing unit 213 and each individual data processing unit 221 are not limited to those described above, and for example, one may perform the operation of the other. The common data processing unit 213 is also called an Upper MAC, Higher MAC, or MLD entity, and the individual data processing unit 221 is also called a Lower MAC.

[0056] During transmission, each signal processing unit 222 performs encoding, interleaving, modulation, etc. on the data unit, adds a physical header, and generates a symbol stream. At this time, each signal processing unit 222 may perform spatial separation processing for MIMO. However, each signal processing unit 222 may not perform spatial separation processing, but may instead apply an arbitrary delay amount (hereinafter referred to as cyclic shift delay (CSD)) to each antenna 250. During reception, each signal processing unit 222 analyzes the physical header and performs demodulation, deinterleaving, decoding, etc. on the symbol stream to generate a data unit. Furthermore, each signal processing unit 222 estimates complex channel characteristics and performs spatial separation processing as necessary.

[0057] During transmission, each wireless interface unit 223 performs digital-to-analog signal conversion, filtering, up-conversion, and phase control on the symbol stream to generate a transmission signal. During reception, each wireless interface unit 223 performs down-conversion, filtering, and analog-to-digital signal conversion on the received signal to generate a symbol stream.

[0058] The amplifier unit 224 of each Non-AP amplifies a signal input from the wireless interface unit 223 or the antenna 250. A part of the amplifier unit 224 may be a component outside the communication unit 210. Alternatively, a part of the amplifier unit 224 may be included in the wireless interface unit 223.

[0059] The control unit 230 controls the communication unit 210 and the communication control unit 211. The control unit 230 may also perform some of the operations of the communication control unit 211. The communication control unit 211 and the control unit 230 may be configured as a single block. The control unit of the communication device according to the present disclosure corresponds to the communication control unit 211, for example, or corresponds to at least one of the communication unit 210 and the communication control unit 211. The communication device according to the present disclosure includes the communication control unit 211, for example, and may also include other components, for example, at least one of STA1 and STA2.

[0060] The storage unit 240 holds information used by the control unit 230 and the communication unit 210. The storage unit 240 may also perform part of the operations of the communication storage unit 212. The storage unit 240 and the communication storage unit 212 may be configured as a single block.

[0061] Each non-AP may also include a storage unit. Note that although in this embodiment the frequencies (or frequency bands) of the links used by each non-AP are different, the same case is not excluded.

[0062] The individual data processing unit 221 and the signal processing unit 222 may be configured as one set, and multiple sets may be connected to one wireless interface unit 223. In other words, one wireless interface unit 223 may be shared by multiple Non-APs.

[0063] Furthermore, a configuration may be adopted in which a wireless interface unit 223, an amplifier unit 224, and an antenna 250 are grouped together, and multiple groups are connected to one signal processing unit 222. In other words, the signal processing unit 222 may be shared by multiple APs. In this case, there may be one or multiple individual data processing units 221.

[0064] FIG. 5 shows an example of the overall configuration of a wireless communication system of a first comparative example.

[0065] In the first comparative example, we will discuss seamless roaming, in which a single AP MLD is used as the non-AP MLD 100 and seamlessly switches connections. Fig. 5A shows the link state before roaming in seamless roaming, and Fig. 5B shows the link state after roaming.

[0066] In the state of FIG. 5A , STA1-1 establishes a link with AP1-1 and becomes active. As a result, the Non-AP MLD 100 is connected to the router 5 via AP1-1, forming a data path. Seamless roaming is implemented based on changes in communication conditions. For example, the Non-AP MLD 100 implements Seamless roaming in response to deterioration in communication quality of link 1. During roaming, the Non-AP MLD 100 establishes links with AP1-1 and AP1-2, and transmits, for example, packets to the Non-AP MLD 100 from both the links of AP1-1 and AP1-2. After roaming, STA1-1 establishes a link with AP1-2 and becomes active. As a result, the Non-AP MLD 100 is connected to the router 5 via AP1-2, forming a data path.

[0067] FIG. 6 shows an example of the overall configuration of a wireless communication system of a second comparative example.

[0068] In the second comparative example, the Non-AP MLD 100 forms links with multiple APs, with only the AP MLD 1, and adopts the Single Serving AP MLD mode to perform multi-link operation.

[0069] As shown in Fig. 6, in the Single Serving AP MLD mode, the wireless communication system forms multiple links between one of the multiple AP MLDs and a non-AP MLD, and performs multi-link operation. In this example, Link 1 and Link 2 are formed between AP MLD 1 and Non-AP MLD 100.

[0070] FIG. 7 is a diagram illustrating an example of a sequence when multi-link operation is performed in the second comparative example and the like.

[0071] 7, the wireless communication system will compare the sequence when multi-link operation is performed in the Single Serving AP MLD mode described in FIG. 6 with the sequence when multi-link operation is performed in the Multiple Serving AP MLD mode of this embodiment. The sequence will be described assuming that AP MLD1, AP MLD2, and Non-AP MLD 100 have agreed to perform NSTR operation.

[0072] In multi-link operation, when AP MLDs 1 and 2 transmit data to the non-AP MLD 100 forming the NSTR link pair via different links, they need to align the transmission end times to transmit the data so that transmission and reception do not occur simultaneously in the non-AP MLD 100. Hereinafter, transmitting data with the same transmission end time will be referred to as end time alignment.

[0073] In the Single Serving AP MLD mode, which is the configuration of the second comparative example, the APs that send data to the Non-AP MLD 100 are contained within the same device, so end time alignment can be achieved solely through control within the device. On the other hand, in the Multiple Serving AP MLD mode, the APs that send data to the Non-AP MLD 100 belong to different devices, so control such as information exchange between devices is required to achieve end time alignment.

[0074] In the example of Single Serving AP MLD mode described in FIG. 6 , the AP MLD 1 and the Non-AP MLD 100 form link 1 between AP 1-1 and Non-AP STA 1-1, and link 2 between AP 1-2 and Non-AP STA 1-2. In Single Serving AP MLD mode, for example, when transmitting data from AP MLD 1 using links 1 and 2, the Non-AP MLD 100 performs end time alignment before transmitting the data so that transmission and reception do not occur simultaneously. Furthermore, after receiving each piece of data, the Non-AP MLD 100 aligns the transmission start times of BAs (Block Acks) and transmits them at the same time at Non-AP STA 1-1 and Non-AP STA 1-2. In this way, in Single Serving AP MLD mode, the AP MLD 1 can achieve end time alignment solely through control within the device.

[0075] On the other hand, in the example of Multiple Serving AP MLD mode described in FIG. 1 , AP MLD2 and Non-AP MLD 100 form link 1 between AP 2-2 and Non-AP STA 1-2, and AP MLD 1 and Non-AP MLD 100 form link 2 between AP 1-1 and Non-AP STA 1-1. When AP MLD 1 and AP MLD 2 transmit Data 1 and Data 2 to Non-AP MLD 100, respectively, AP MLD 2 requires the information of Data 1 included in AP MLD 1 when performing end time alignment. A method of performing multi-link operation in Multiple Serving AP MLD mode will be described below.

[0076] FIG. 8 is an example of a flowchart when AP MLD1 and AP MLD2 perform multi-link operation in the first embodiment.

[0077] In this example, a flow in which AP MLD1 performs multi-link operation will be described. In step S1, the control unit 130 of AP MLD1 determines whether to perform NSTR operation. For example, the control unit 130 of AP MLD1 determines whether to perform NSTR operation based on the configuration information stored in the storage unit 140. Alternatively, the control unit 130 may obtain information from the non-AP MLD indicating whether the non-AP MLD is in an STR or NSTR state, and determine whether to perform NSTR operation based on this information. This information indicating whether the non-AP MLD is in an STR or NSTR state may be included in a Multi-Link Operation Update Request frame transmitted from the non-AP MLD to AP MLD1. Either AP MLD1 or AP MLD2 may determine whether an NSTR link pair exists among the multiple links formed between the non-AP MLD and the AP MLD1 or AP MLD2, and determine whether to perform NSTR operation based on this determination.

[0078] In step S2, the control unit 130 of the AP MLD1 controls the communication control unit 111 to acquire communication environment information. The control unit 130 of the AP MLD1 acquires, as communication environment information, for example, information on the backhaul connecting the AP MLD1 and AP MLD2 and information on the Non-AP MLD 100 from the SMD AP MLD 3. Examples of backhaul information include information indicating the line type (wired or wireless), information indicating the communication status (for example, information indicating whether communication is possible, information indicating the communication speed, information indicating the amount of delay, information indicating the degree of interference, and information indicating the error rate). Examples of Non-AP MLD 100 information include information indicating the current connection mode of the Non-AP MLD 100.

[0079] In step S3, the control unit 130 of AP MLD1 controls the communication control unit 111 to exchange information indicating the communication status in Multiple Serving AP MLD mode with another AP MLD, AP MLD2, via the backhaul. As information indicating the communication status in Multiple Serving AP MLD mode, the control unit 130 of AP MLD1 exchanges, for example, information indicating the backhaul communication speed with AP MLD2. In addition, the information indicating the communication status may be information indicating whether communication is possible, information indicating the amount of delay, information indicating the degree of interference, or information indicating the error rate. Furthermore, as information indicating the communication status in Multiple Serving AP MLD mode, the control unit 130 of AP MLD1 exchanges information indicating the occupancy rate per unit time of the channels included in each link. Furthermore, the control unit 130 of AP MLD1 exchanges information indicating whether AP MLD2 is within a range where wireless communication is possible.

[0080] In step S4, the control unit 130 of AP MLD2 determines, based on the information exchanged in step S3, whether or not a PPDU can be transmitted to the non-AP MLD 100 without start time sync, using a threshold value. For example, if the backhaul communication speed is equal to or less than the threshold value, the control unit 130 of AP MLD2 determines that the PPDU cannot be transmitted without start time sync, and determines that AP MLDs 1 and 2 should transmit the PPDU to the non-AP MLD 100 with start time sync. On the other hand, if the backhaul communication speed is equal to or greater than the threshold value, the control unit 130 of AP MLD2 determines that the PPDU can be transmitted without start time sync, and determines that AP MLDs 1 and 2 should transmit the PPDU to the non-AP MLD 100 without start time sync. The control unit 130 of AP MLD2 may use a predetermined threshold value when determining whether or not start time sync is possible, or may use a dynamically changing threshold value. The PPDU transmission method is determined based on an MS Info request, an MS Info response, and an MS Info confirm, which will be described later.

[0081] If the control unit 130 of AP MLD2 determines that the PPDU can be transmitted without start time sync (Yes in step S4), in step S5, the control unit 130 of AP MLD1 acquires information specifying the transmission end time of the PPDU in AP MLD2. The information specifying the transmission end time of the PPDU includes, for example, at least one of information specifying the transmission start time of the PPDU and information specifying the length of the PPDU. For example, the information specifying the transmission end time of the PPDU may be information indicating the period from the transmission end time of the frame in which the information is written to the transmission end time of the data frame being transmitted at that time.

[0082] Furthermore, in step S5, the control unit 130 of AP MLD1 determines a route for acquiring information specifying the PPDU transmission end time in AP MLD2 based on the backhaul communication speed. For example, the control unit 130 of AP MLD1 calculates the time required to exchange information specifying the PPDU transmission end time from the backhaul communication speed, and if this time is less than a predetermined first time, the control unit 130 of AP MLD1 acquires information specifying the PPDU transmission end time in AP MLD2 via the backhaul. Furthermore, if the time required for information exchange via the backhaul is equal to or greater than the predetermined first time, the control unit 130 of AP MLD1 acquires information specifying the PPDU transmission end time via the link formed between AP MLD1 and AP MLD2. The determination of whether the time is less than or greater than the predetermined first time is performed using a threshold value. Here, the information specifying the end time of the PPDU transmission is obtained using a link that AP MLD2 does not use to transmit the PPDU, but if the information specifying the end time of the PPDU transmission can be obtained on a link that AP MLD2 used to transmit the PPDU, the control unit 130 of AP MLD1 may obtain it using that link.

[0083] The control unit 130 of the AP MLD1 may also dynamically change the threshold value used as the predetermined first time. For example, these threshold values ​​may be changed based on information transmitted between the AP MLD1 and the non-AP MLD1 before transmitting or receiving a data frame, more specifically, information described in a QoS Characteristics element included in an SCS Request frame used in the Stream Classification Service, information indicating a required delay during packet transmission such as a Delay Bound, or information indicating a PPDU transmission completion time. The control unit 130 of the AP MLD1 may also set the threshold value to a required delay value based on the information described in the QoS Characteristics element and information indicating a required delay during packet transmission such as a Delay Bound. The control unit 130 of the AP MLD1 may also set the threshold value to an average PPDU transmission completion time based on information indicating a PPDU transmission completion time.

[0084] Furthermore, when the control unit 130 of AP MLD1 acquires information specifying the transmission end time of a PPDU using the link between AP MLD1 and AP MLD2, if decoding of the acquired information fails or the link is not working, the control unit 130 of AP MLD1 may request a retransmission from AP MLD2, which is the sender of the information. This retransmission request may be made using a backhaul or a link different from the link used to acquire the information.

[0085] In step S6, the control unit 130 of AP MLD1 controls the communication control unit 111 to perform end time alignment using information specifying the PPDU transmission end time, transmits the PPDU to the Non-AP MLD 100, and ends the process. For example, the control unit 130 of AP MLD1 calculates the PPDU transmission end time in AP MLD2 from at least one of the information specifying the PPDU transmission start time and the information specifying the PPDU length, and controls the PPDU length so that transmission of the PPDU of AP MLD1 is completed simultaneously with the transmission end time.

[0086] If the control unit 130 of AP MLD2 determines that the PPDU cannot be transmitted without start time sync (No in step S4), in step S7 the control unit 130 of AP MLD1 controls the communication control unit 111 to perform start time sync and transmit the PPDU to the Non-AP MLD 100. Start time sync is performed, for example, by transmitting a Trigger frame to AP MLD2 when AP MLD1 acquires a transmission opportunity, thereby inducing the transmission of a PPDU to the Non-AP MLD 100. Furthermore, the control unit 130 of AP MLD1 performs end time alignment in the same manner as described above and transmits the PPDU to the Non-AP MLD 100.

[0087] FIG. 9 shows an example of a format of a frame of information specifying the transmission end time of a PPDU in the first embodiment.

[0088] Frame Control describes information indicating the type of frame, etc. End time alignment describes information related to the end time alignment of data, which specifies the end time of the PPDU transmission. For example, information indicating the period from the end time of transmission of this frame to the end time of transmission of the data frame being transmitted at that time is described.

[0089] RA (Receiver Address) contains information to identify the receiving device of this frame. TA (Transmitter Address) contains information to identify the transmitting device of this frame. FCS (Frame Check Sequence) contains information to detect errors in this frame.

[0090] The frame format is an example and is not limited to this format. For example, the data may be written using an element, or may be written in the Frame Body of a normal QoS Data frame.

[0091] FIG. 10 is a diagram illustrating an example of a sequence when multi-link operation is performed in the first embodiment.

[0092] In the following description, another communication device as seen from the communication device AP MLD1 refers to AP MLD 2, and another communication device as seen from the communication device AP MLD 2 refers to AP MLD 1. Furthermore, the configuration of the wireless communication system may include communication devices other than AP MLD 1 or AP MLD 2.

[0093] Furthermore, AP MLD2, which is a communication device that transmits Data1 to Non-AP MLD, is shown as an example of a first communication device, and AP MLD1, which transmits Data2 or Data3 to Non-AP MLD, is shown as an example of a third communication device. The first communication device and the third communication device can perform similar operations, and AP MLD1 may be the first communication device, and AP MLD2 may be the third communication device. Furthermore, Non-AP MLD is an example of a second communication device.

[0094] In the following, a communication path configured by a backhaul or a link is referred to as a communication path. A communication path may include both a wired line and a wireless line. In this embodiment, an example in which a backhaul is configured by a wired line is described, but the backhaul may include a wireless section or may be configured entirely by a wireless line. In addition, an example in which a link is configured by a wireless line is described, but the backhaul may include a wired section or may be configured entirely by a wired line.

[0095] 10 shows an example in which Non-AP MLD 100 forms Link 1 and Link 2 as an NSTR link pair between AP MLD 1 and AP MLD 2, and AP MLD 1 and AP MLD 2 share information specifying the PPDU transmission end time via the backhaul, thereby performing end time alignment. The overall configuration diagram is the same as that shown in FIG. 1, so a detailed explanation will be omitted. In this example, the flow described in steps S1 and S2 above will be assumed to have already been implemented. Link 1 and Link 2 are examples of a first communication path, and the backhaul is an example of a second communication path.

[0096] AP MLD1 and AP MLD2 exchange information (MS Info) indicating the communication status in Multiple Serving AP MLD mode under the control of the control unit 130. In this example, AP MLD2 transmits an MS Info request to AP MLD1, and AP MLD1 replies with an MS Info response. Upon receiving the MS Info response, AP MLD2 determines under the control of the control unit 130 not to perform PPDU start time sync; in other words, it determines that each AP MLD will independently acquire a transmission opportunity, and notifies AP MLD1 of the decision in an MS Info confirm.

[0097] This frame exchange may be performed when the AP MLD1, AP MLD2, and Non-AP MLD 100 establish a connection, or may be performed immediately before exchanging data frames. Also, Fig. 10 shows an example in which the MS Info request is transmitted via a link established between AP2-2 and AP1-2, the MS Info response is transmitted via a link established between AP1-2 and AP2-2, and the MS Info confirm is transmitted via a link established between AP2-2 and AP1-2. This frame exchange may be performed via links other than those described above, or may be performed via a backhaul.

[0098] Furthermore, when AP MLD is used as the AP used in the network instead of AP SLD, Multiple Serving Info request / response / confirm may be transmitted using any available link between AP MLD1 and AP MLD2. Furthermore, the exchange of Multiple Serving Info request / response / confirm does not have to be performed entirely over the same link, and some or all of them may be exchanged over different links.

[0099] After AP2-2 acquires a transmission opportunity, AP2-2 transmits Data1 to Non-AP STA1-2 under the control of the control unit 130, and transmits information specifying the transmission end time of Data1 to AP MLD1 via the backhaul as information specifying the transmission end time of the PPDU. After receiving the information specifying the transmission end time of Data1 via the backhaul under the control of the control unit 130, AP MLD1 acquires a transmission opportunity with AP1-1, performs end time alignment based on this information, controls the length of the PPDU so that transmission of Data1 ends simultaneously, and transmits Data2 to Non-AP MLD 100. As shown in FIG. 10 , Data2 is transmitted via a link different from the link used for transmitting Data1. Data1 is an example of a first signal, and the information specifying the transmission end time of the PPDU is an example of information regarding the transmission end time of the first signal. Furthermore, the signal including the information specifying the transmission end time of the PPDU is an example of a second signal, and Data2 is an example of a third signal.

[0100] Furthermore, Data1 and Data2 may be transmitted via links other than those mentioned above. For example, Data1 may be transmitted from AP2-1 to Non-AP1-1, and Data2 may be transmitted from AP1-2 to Non-AP1-2.

[0101] Furthermore, under the control of the control unit 230, the non-AP MLD 100 synchronizes the transmission start times of BAs at the non-AP STA1-1 and non-AP STA1-2 after receiving each piece of data, and transmits the BAs to the AP1-1 and AP2-2.

[0102] FIG. 11 shows an example of the format of a Multiple Serving Info Action (Request / Response / Confirm) frame in the first embodiment.

[0103] FIG. 11 shows an example of the format of a frame exchanged to determine the PPDU transmission method etc. in the Multiple Serving AP MLD mode.

[0104] The Category field contains information indicating that this frame contains information showing the communication status in Multiple Serving AP MLD mode. The Multiple Serving Action field contains information indicating whether each frame is a Multiple Serving Info Request, Response, or Confirm.

[0105] The Dialog Token contains the same information as the corresponding Request / Response / Confirm and contains information indicating the relationship between the Request / Response / Confirm. The Status Code contains information indicating the status of Multiple Serving AP MLD mode. For example, if the result of the Request is that Multiple Serving AP MLD mode cannot be implemented, details of this are included in the Response / Confirm frame.

[0106] Capability contains information indicating the capability of the STA sending this frame. Supported Backhaul Rates contains information indicating the backhaul communication speeds that can be used for communication between APs and MLDs.

[0107] Reachability contains information indicating whether the AP MLDs are within a wireless communication range. Link Status contains information indicating the occupancy rate per unit time of the channels included in each link used by the AP MLD.

[0108] PPDU Transmission Type describes information indicating the PPDU transmission method in Multiple Serving AP MLD mode.

[0109] According to this embodiment, an AP MLD receives information specifying the end time of a PPDU transmission from another AP MLD via the backhaul, and performs end time alignment between the AP MLDs. This allows the AP MLD to transmit or receive data using two links, without limiting the operation of the Multiple Serving AP MLD mode to one link.

[0110] Furthermore, according to this embodiment, the Non-AP MLD 100 transmits or receives data from different AP MLDs using two links, thereby achieving diversity and improving communication quality.

[0111] Second Embodiment FIG. 12 is a diagram illustrating an example of a sequence when multi-link operation is performed in the second embodiment.

[0112] The Non-AP MLD 100 forms Link 1 and Link 2 as an NSTR link pair between the AP MLD 1 and AP MLD 2. In this embodiment, an example will be described in which the AP MLD 1 determines not to perform end time alignment based on the result of receiving information specifying the PPDU transmission end time via the backhaul.

[0113] Depending on the size of the data transmitted by the AP MLD, end time alignment may not be possible. In such a case, the AP MLD 1 that has received information specifying the PPDU transmission end time transmits data to other subordinate terminals, not to the Non-AP MLD 100, without controlling the PPDU length.

[0114] In this embodiment, the overall configuration diagram is the same as in Fig. 1, and therefore a description thereof will be omitted. Also, the flow for determining the PPDU transmission method and the like in Multiple Serving AP MLD mode is the same as in Fig. 8, and therefore a description thereof will be omitted.

[0115] After notifying MS Info confirm, AP MLD2 transmits information specifying the transmission end time of Data1 to AP MLD1 via the backhaul under the control of the control unit 130. AP MLD1 receives information specifying the transmission end time of Data1 via the backhaul under the control of the control unit 130. AP MLD1 acquires a transmission opportunity at AP1-1 and, based on this information, determines whether it can transmit Data2 to Non-AP STA1-1 so that transmission ends simultaneously with Data1. In this example, AP1-1 determines under the control of the control unit 130 that it cannot complete transmission of Data2 simultaneously with Data1. Furthermore, AP MLD1 determines under the control of the control unit 130 to transmit Data3 to a subordinate terminal (not shown) other than Non-AP STA1-1 as a different destination without controlling the PPDU length. AP MLD1 determines under the control of the control unit 130 not to transmit data if the subordinate terminal has no data to transmit. Furthermore, Non-AP STA1-2 transmits a BA to SP2-2 after receiving Data1 under the control of the control unit 130. Data3 is an example of a fourth signal.

[0116] After receiving the BA, AP MLD2 transmits Data1' to Non-AP STA1-2 at the following timing under the control of the control unit 130. After AP 2-2 acquires a transmission opportunity, AP 2-2 transmits Data1' to Non-AP STA1-2 under the control of the control unit 130, and transmits information specifying the transmission end time of Data1' to AP MLD1 over the backhaul as information specifying the transmission end time of the PPDU. After AP MLD1 receives the information specifying the transmission end time of Data1' over the backhaul under the control of the control unit 130, it acquires a transmission opportunity with AP 1-1. If AP MLD1 determines based on this information that it can transmit Data2 to Non-AP STA1-1 so that transmission ends simultaneously with Data1', it transmits Data2 to Non-AP STA1-1 under the control of the control unit 130. In this case, under the control of the control unit 130, the AP MLD 1 performs end time alignment at AP 1-1, controls the length of the PPDU so that transmission of Data 1' is completed at the same time, and transmits Data 2 to the Non-AP MLD 100. Data 1' is an example of the first data.

[0117] Furthermore, under the control of the control unit 230, the non-AP MLD 100 synchronizes the transmission start times of BAs at the non-AP STA1-1 and non-AP STA1-2 after receiving each piece of data, and transmits the BAs to the AP1-1 and AP2-2.

[0118] According to this embodiment, the AP MLD receives information specifying the PPDU transmission end time from another AP MLD via the backhaul, and determines whether to perform end time alignment and transmit data based on this information. As a result, if the AP MLD is unable to transmit data to the Non-AP MLD 100 after performing end time alignment, it can allocate bandwidth for data transmission by other subordinate terminals.

[0119] Third Embodiment FIG. 13 is a diagram illustrating an example of a sequence when multi-link operation is performed in a third embodiment.

[0120] The Non-AP MLD 100 forms link 1 and link 2 as an NSTR link pair between the AP MLD 1 and AP MLD 2. In this embodiment, an example will be described in which the AP MLD 1 receives information specifying the PPDU transmission end time not via the backhaul but via the link formed between the AP MLD 1 and AP MLD 2, and performs end time alignment.

[0121] In this embodiment, the overall configuration diagram is the same as in Fig. 1, and therefore a description thereof will be omitted. Also, the flow for determining the PPDU transmission method and the like in Multiple Serving AP MLD mode is the same as in Fig. 8, and therefore a description thereof will be omitted.

[0122] Under the control of the control unit 130, AP MLD2 notifies AP MLD1 of MS Info confirm, and then transmits information specifying the transmission end time of Data1 (represented as Data1 Info in FIG. 13 ) to AP MLD1 via the link formed between AP MLD1 and AP MLD2. At this time, under the control of the control unit 130, AP MLD2 transmits Data1 Info using AP2-1, which is an AP different from AP2-2 used to transmit Data1. In this example, AP MLD1 and 2 form a link between AP2-1 and AP1-1, and transmit Data1 Info via this link. Link 1 and link 2 are examples of a first communication path, and the link formed between AP MLD1 and AP MLD2 is an example of a third communication path.

[0123] AP MLD1 receives Data1 Info via this link under the control of the control unit 130 and then acquires a transmission opportunity at AP1-1. AP MLD1 performs end time alignment based on Data1 Info under the control of the control unit 130, and transmits Data2 to the non-AP MLD 100 by controlling the length of the PPDU so that transmission of Data1 ends simultaneously.

[0124] Furthermore, under the control of the control unit 230, the non-AP MLD 100 synchronizes the transmission start times of BAs at the non-AP STA1-1 and non-AP STA1-2 after receiving each piece of data, and transmits the BAs to the AP1-1 and AP2-2.

[0125] According to this embodiment, an AP MLD receives information specifying the PPDU transmission end time from another AP MLD using a link formed with the other AP MLD, and performs end time alignment between the AP MLDs. This allows the AP MLD to transmit or receive data using two links, without limiting the operation of the Multiple Serving AP MLD mode to one link.

[0126] Furthermore, in this embodiment, an AP MLD receives information specifying the end time of PPDU transmission from another AP MLD using a link formed between them, so even if information cannot be exchanged between AP MLDs using backhaul, end time alignment can be performed between AP MLDs.

[0127] Fourth Embodiment FIG. 14 is a diagram illustrating an example of a sequence when multi-link operation is performed in the fourth embodiment.

[0128] The Non-AP MLD 100 forms links 1 and 2 as an NSTR link pair between the AP MLD 1 and AP MLD 2. In this embodiment, an example will be described in which the receiving AP MLD 1 requests information specifying the transmission end time of a PPDU using the link formed between the AP MLD 1 and AP MLD 2.

[0129] When transmitting or receiving information specifying the transmission end time of a PPDU over the backhaul, there may be cases where transmission or reception is not possible due to, for example, a malfunction in the backhaul. For example, if the receiving AP MLD1 fails to receive the information specifying the transmission end time of the PPDU within a predetermined first time period, it determines that it has failed to obtain the information specifying the transmission end time of the PPDU over the backhaul and sends an information request to the transmitting AP MLD2. In the following example, a timeout period is set, and if the information specifying the transmission end time of the PPDU is not received within this period, the AP MLD1 requests a retransmission.

[0130] In this embodiment, the overall configuration diagram is the same as in Fig. 1, and therefore a description thereof will be omitted. Also, the flow for determining the PPDU transmission method and the like in Multiple Serving AP MLD mode is the same as in Fig. 8, and therefore a description thereof will be omitted.

[0131] After notifying MS Info confirm, AP MLD2 transmits, via the backhaul, information specifying the transmission end time of Data 1 to AP MLD 1. If the control unit 130 of AP MLD1 fails to receive the information specifying the transmission end time of Data 1 within the timeout period, it determines that it has failed to obtain the information and makes a request (represented as PPDU Info req in FIG. 14) for information specifying the transmission end time of the PPDU.

[0132] Under the control of the control unit 130, AP MLD2 transmits a PPDU Info req via the link between AP MLD1 and AP MLD2 that is not used to transmit Data1. In this example, under the control of the control unit 130, AP MLD1 transmits a PPDU Info req to AP MLD2 using the link formed between AP1-1 and AP2-1. Under the control of the control unit 130, AP MLD2 retransmits Data1 Info after receiving the PPDU Info req. At this time, Data1 Info is transmitted using the link formed between AP1-1 and AP2-1, which is the link not used to transmit Data1. Link 1 and Link 2 are examples of a first communication path, the backhaul is an example of a second communication path, and the link formed between AP MLD1 and AP MLD2 is an example of a third communication path.

[0133] Under the control of the control unit 130, after receiving Data1 Info, AP MLD1 acquires a transmission opportunity at AP1-1, controls the length of the PPDU so that transmission ends simultaneously with Data1, and transmits Data2 using Link 1.

[0134] Furthermore, the control unit 130 may determine whether the information specifying the transmission end time of Data1 has been successfully acquired, for example, based on a timeout period stored in the storage unit 140. For example, if the control unit 130 of AP MLD1 receives MS Info confirm and then fails to acquire the information specifying the transmission end time of Data1 within the timeout period, the control unit 130 determines that the acquisition of the information has failed.

[0135] Furthermore, under the control of the control unit 230, the non-AP MLD 100 synchronizes the transmission start times of BAs at the non-AP STA1-1 and non-AP STA1-2 after receiving each piece of data, and transmits the BAs to the AP1-1 and AP2-2.

[0136] According to this embodiment, if an AP MLD fails to receive information specifying the transmission end time of a PPDU via the backhaul, it requests the information using a link formed with another AP MLD that is the source of the information. As a result, even if an AP MLD fails to obtain information via the backhaul, it can obtain information specifying the transmission end time of the PPDU using the link between AP MLDs, and end time alignment can be performed between AP MLDs.

[0137] Fifth Embodiment FIG. 15 is a diagram illustrating an example of a sequence when multi-link operation is performed in the fifth embodiment.

[0138] In this embodiment, an example will be described in which AP MLD2 transmits information specifying the PPDU transmission end time to AP MLD1 during RTS / CTS frame exchange performed before data transmission, and each AP MLD performs end time alignment. The overall configuration diagram is the same as in Figure 1, so its explanation will be omitted.

[0139] Under the control of the control unit 130, AP MLD1 and AP MLD2 exchange information (MS Info) indicating the communication status in Multiple Serving AP MLD mode to determine the PPDU transmission method. In this example, the control unit 130 determines the PPDU transmission method for the Non-AP MLD 100. In this example, AP MLD2 transmits an MS Info request to AP MLD1, and AP MLD1 replies with MS Info via an MS Info response. In this example, under the control of the control unit 130, AP MLD2 determines not to perform start time sync, that is, determines that each AP MLD will independently acquire a transmission opportunity, and notifies AP MLD1 of the determination in an MS Info confirm.

[0140] This frame exchange may be performed when the connection between the AP MLD1, AP MLD2, and Non-AP MLD 100 is established, or may be performed immediately before the data frame exchange. Also, Fig. 15 shows an example in which the MS Info request is transmitted via the link formed between AP2-2 and AP1-2, the MS Info response is transmitted via the link formed between AP1-2 and AP2-2, and the MS Info confirm is transmitted via the link formed between AP2-2 and AP1-2. This frame exchange may be performed via links other than those described above, or may be performed via the backhaul.

[0141] After AP2-2 acquires a transmission opportunity, it exchanges RTS / CTS with non-AP STA1-2. At this time, AP MLD2, under the control of the control unit 130, includes information specifying the transmission end time of Data1 in the RTS as information specifying the transmission end time of the PPDU, and also transmits the RTS to AP MLD1-2. After receiving CTS from non-AP STA1-2, AP2-2 transmits Data1 to non-AP STA1-2.

[0142] Under the control of the control unit 130, the AP MLD1 receives information specifying the end time of transmission of Data1 by RTS / CTS, and then acquires a transmission opportunity at AP1-1. Based on this information, it performs end time alignment and controls the length of the PPDU to transmit Data2 to the Non-AP MLD 100 so that the transmission of Data1 ends simultaneously.

[0143] According to this embodiment, the AP MLD transmits information specifying the PPDU transmission end time in the RTS. This allows the reuse of existing protocol assets defined in IEEE 802.11. This reduces the need for changes to existing specifications and prevents adverse effects on communication between AP MLDs.

[0144] Sixth Embodiment FIG. 16 is a diagram illustrating an example of a sequence when multi-link operation is performed in the sixth embodiment.

[0145] In this embodiment, an example will be described in which the AP MLD 2 determines not to transmit information specifying the PPDU transmission end time, and controls each AP MLD operating in Multiple Serving AP MLD mode to transmit data simultaneously, thereby performing NSTR operation. The overall configuration diagram is the same as in Figure 1, so its description will be omitted.

[0146] In this embodiment, AP MLD1 and AP MLD2 exchange information (MS Info) indicating the communication status in Multiple Serving AP MLD mode under the control of each control unit 130 to determine the PPDU transmission method. In this example, the PPDU transmission method for non-AP MLD 100 is determined. AP MLD2 transmits an MS Info request to AP MLD1, and AP MLD1 replies with MS Info by means of an MS Info response. In this example, upon receiving the MS Info response, AP MLD2, under the control of the control unit 130, determines to perform trigger-base access to non-AP MLD 100, which synchronizes the start times of Data1 and Data2, and notifies AP MLD1 of this by means of an MS Info confirm.

[0147] Trigger-base access is executed, for example, when the control unit 130 of AP MLD2 determines that a PPDU cannot be transmitted without start time sync after exchanging information (MS Info) indicating the communication status in Multiple Serving AP MLD mode. For example, if the backhaul communication speed is equal to or less than a threshold, the control unit 130 of AP MLD2 determines that a PPDU cannot be transmitted without start time sync, and determines that AP MLD1 and 2 should transmit a PPDU to Non-AP MLD 100 by trigger-base access.

[0148] In this example, after AP2-2 acquires a transmission opportunity, AP2-2 transmits a trigger frame to AP1-2. In this example, AP2-2 acquires a transmission opportunity first and transmits a trigger frame, and then AP2-1 acquires a transmission opportunity and transmits a trigger frame. As an example, the control unit 130 may perform control so that the timing at which trigger frames are started to be transmitted on each link of AP MLD2 is synchronized, and the trigger frames are transmitted simultaneously. Alternatively, the control unit 130 may perform control so that AP2-1 starts transmitting a trigger frame first, and then AP2-2 transmits a trigger frame.

[0149] Also, Figure 16 shows an example in which each AP MLD1 and 2 aligns the transmission start timing based on the transmission of a Trigger frame by AP MLD2, but any frame that can ensure a transmission opportunity for simultaneously transmitting data may be used, such as a CTS frame.

[0150] After AP1-1 receives the Trigger frame, AP MLDs 1 and 2 transmit Data1 and Data2, respectively, to non-AP MLD 100 so that their transmission start timings are synchronized.

[0151] Furthermore, after receiving each piece of data, the non-AP MLD 100 synchronizes the start times of BA transmission at the non-AP STA1-1 and non-AP STA1-2 and transmits the BA to the AP1-1 and AP2-2.

[0152] According to this embodiment, an AP MLD receives a frame that triggers another AP MLD to secure a transmission opportunity through trigger-base access. This allows each AP MLD to transmit data simultaneously, and allows data transmission or reception using two links, rather than limiting the Multiple Serving AP MLD mode to single-link operation.

[0153] Seventh Embodiment FIG. 17 is a diagram illustrating an example of a sequence when multi-link operation is performed in the seventh embodiment.

[0154] In this embodiment, an example will be described in which the AP MLD 2 transmits a PPDU after determining not to share information specifying the PPDU transmission end time with the AP MLD 1. The overall configuration diagram is the same as in Fig. 1, so a description thereof will be omitted.

[0155] In this embodiment, AP MLD1 and AP MLD2 exchange information (MS Info) indicating the communication status in Multiple Serving AP MLD mode under the control of each control unit 130 to determine the PPDU transmission method. In this example, the control unit 130 determines the PPDU transmission method for Non-AP MLD 100. Upon receiving the MS Info response, AP MLD2 determines under the control of the control unit 130 that each MLD will independently acquire a transmission opportunity, and notifies AP MLD1 of this by means of an MS Info confirm. Furthermore, under the control of the control unit 130, AP MLD2 determines not to share information specifying the PPDU transmission end time with AP MLD1, and notifies MS Info confirm.

[0156] After AP2-2 acquires a transmission opportunity, AP2-2 transmits Data1 to non-AP STA1-2 with the no ack policy under the control of the control unit 130. After AP MLD1 acquires a transmission opportunity, AP1-1 transmits Data2 to non-AP STA1-1 under the control of the control unit 130.

[0157] Upon receiving Data2, non-AP STA1-1 returns a BA including whether Data1 and Data2 were successfully received to AP1-1 and AP2-2 under the control of the control unit 230. Alternatively, non-AP STA1-1 may send a BA only to AP1-1, after which AP MLD1 may send information including whether Data1 was successfully received from AP1-1 or AP1-2 to AP MLD2. Alternatively, non-AP STA1-1 may return a BA to AP1-1 and AP2-2 after a predetermined delay has elapsed, rather than after receiving Data2.

[0158] According to this embodiment, the AP MLD transmits data to the Non-AP MLD 100 using the no ack policy. This allows the AP MLD to transmit or receive data using two links in Multiple Serving AP MLD mode without sharing information specifying the PPDU transmission end time between AP MLDs.

[0159] <Example of Computer Configuration> The above-described series of processes can be executed by hardware or software. When the series of processes is executed by software, the program constituting the software is installed from a program recording medium into a computer incorporated in dedicated hardware, or into a general-purpose personal computer, etc.

[0160] FIG. 18 is a block diagram showing an example of the hardware configuration of a computer that executes the above-described series of processes by a program.

[0161] A CPU (Central Processing Unit) 801 , a ROM (Read Only Memory) 802 , and a RAM (Random Access Memory) 803 are interconnected by a bus 804 .

[0162] An input / output interface 805 is also connected to the bus 804. An input unit 806 including a keyboard, a mouse, etc., and an output unit 807 including a display, a speaker, etc. are connected to the input / output interface 805. In addition, a storage unit 808 including a hard disk, a nonvolatile memory, etc., a communication unit 809 including a network interface, etc., and a drive 810 that drives removable media 811 are also connected to the input / output interface 805.

[0163] In a computer configured as described above, the CPU 801 performs the above-described series of processes by, for example, loading a program stored in the storage unit 808 into the RAM 803 via the input / output interface 805 and the bus 804 and executing it.

[0164] The program executed by the CPU 801 is provided, for example, by being recorded on a removable medium 811 or via a wired or wireless transmission medium such as a local area network, the Internet, or digital broadcasting, and is installed in the storage unit 808.

[0165] The program executed by the computer may be a program that processes in chronological order according to the order described in this specification, or may be a program that processes in parallel or at the required timing, such as when called.

[0166] <Application Examples> The present technology can be applied to various products. For example, the communication devices in Figures 3 and 4 may be realized as mobile terminals such as smartphones, tablet PCs (Personal Computers), notebook PCs, portable game consoles, or digital cameras; fixed terminals such as television sets, projectors, printers, digital scanners, or network storage; or in-vehicle terminals such as car navigation systems. Furthermore, the communication devices may be realized as machine-to-machine communication (M2M) terminals such as smart meters, vending machines, remote monitoring devices, or point-of-sale (POS) terminals. Furthermore, the communication devices may be wireless communication modules (e.g., integrated circuit modules configured on a single die) mounted on these terminals.

[0167] On the other hand, for example, the communication device may be realized as a wireless LAN AP (wireless base station) with or without router functionality, or as a mobile wireless LAN router, or as a wireless communication module (e.g., an integrated circuit module configured on a single die) mounted on such a device.

[0168] <Configuration Example of Smartphone> FIG. 19 is a block diagram showing a schematic configuration example of a smartphone to which the present technology is applied.

[0169] The smartphone 900 includes a processor 901, a memory 902, a storage 903, an external connection interface 904, a camera 906, a sensor 907, a microphone 908, an input device 909, and a display device 910. The smartphone 900 also includes a speaker 911, a wireless communication interface 913, an antenna switch 914, an antenna 915, a bus 917, a battery 918, and an auxiliary controller 919.

[0170] The processor 901 may be, for example, a CPU or a SoC (System on Chip), and limits the functions of the application layer and other layers of the smartphone 900.

[0171] The memory 902 includes RAM and ROM, and stores programs and data executed by the processor 901 .

[0172] The storage 903 includes a storage medium such as a semiconductor memory or a hard disk.

[0173] The external connection interface 904 is an interface for connecting an external device such as a memory card or a USB (Universal Serial Bus) device to the smartphone 900 .

[0174] The camera 906 has an imaging element such as a charge coupled device (CCD) or a complementary metal oxide semiconductor (CMOS), and generates a captured image.

[0175] The sensor 907 includes a group of sensors such as a positioning sensor, a gyro sensor, a geomagnetic sensor, and an acceleration sensor.

[0176] The microphone 908 converts the sound input to the smartphone 900 into an audio signal.

[0177] The input device 909 includes, for example, a touch sensor that detects a touch on the screen of the display device 910, a keypad, a keyboard, a button, or a switch, and accepts operations or information input from the user.

[0178] The display device 910 has a screen such as a liquid crystal display (LCD) or an organic light-emitting diode (OLED) display, and displays an output image from the smartphone 900. The display device 910 may also be configured as a projector that projects the output image onto a screen. The speaker 911 converts an audio signal output from the smartphone 900 into audio. The processor 901 also controls the display on the display device 910 based on information received via the first communication path and user operation of the input device 909.

[0179] The wireless communication interface 913 supports one or more wireless LAN standards such as IEEE802.11a, 11b, 11g, 11ac, 11ad, 11ax, 11ay, 11be, 11bn, and successor standards thereof, and performs wireless communication.

[0180] The wireless communication interface 913 communicates with other devices via a wireless LAN AP in infrastructure mode, and directly with other devices in ad hoc mode or a direct communication mode such as Wi-Fi Direct.

[0181] Unlike ad hoc mode, in Wi-Fi Direct, one of the two terminals acts as an AP, but communication is carried out directly between the terminals.

[0182] The wireless communication interface 913 typically includes a baseband processor, an RF (Radio Frequency) circuit, a power amplifier, etc. The wireless communication interface 913 may be a one-chip module that integrates a memory that stores a communication control program, a processor that executes the program, and related circuits.

[0183] The wireless communication interface 913 may support other types of wireless communication methods, such as a short-range wireless communication method, a proximity wireless communication method, or a cellular communication method, in addition to a wireless LAN method.

[0184] The antenna switch 914 switches the connection destination of the antenna 915 between multiple circuits (for example, circuits for different wireless communication methods) included in the wireless communication interface 913 .

[0185] The antenna 915 has a single or multiple antenna elements (e.g., multiple antenna elements constituting a MIMO (Multiple Input Multiple Output) antenna) and is used for transmitting and receiving wireless signals via the wireless communication interface 913. For example, when the antenna 915 has multiple antenna elements, it has a first antenna element and a second antenna element to constitute a MIMO antenna. Furthermore, multiple antennas 915 may be provided, and when the multiple antennas 915 include a first antenna and a second antenna, each may communicate through a respective link in the first communication path.

[0186] 19 , the smartphone 900 may include multiple antennas (for example, an antenna for wireless LAN and an antenna for a close-proximity wireless communication system). In this case, the antenna switch 914 may be omitted from the configuration of the smartphone 900.

[0187] The bus 917 connects the processor 901, memory 902, storage 903, external connection interface 904, camera 906, sensor 907, microphone 908, input device 909, display device 910, speaker 911, wireless communication interface 913, and auxiliary controller 919 to each other.

[0188] 19 via power supply lines partially indicated by dashed lines in the figure. The auxiliary controller 919 operates the minimum necessary functions of the smartphone 900, for example, in sleep mode.

[0189] 19 , for example, the communication control unit 111 and the control unit 130 in FIG. 3 may be implemented in the wireless communication interface 913. Furthermore, at least some of these functions may be implemented in the processor 901 or the auxiliary controller 919.

[0190] The smartphone 900 may operate as a wireless AP (software AP) by having the processor 901 execute an AP function at the application level. The wireless communication interface 913 may also have a wireless AP function. Payload data received via a cellular communication method may be transmitted via a wireless LAN method, or payload data received via a wireless LAN method may be transmitted via a cellular communication method. The smartphone 900 may enable or disable its AP function based on a user setting operation. When the AP function is enabled, the smartphone 900 may operate as AP MLD1 or AP MLD2 in the above-described embodiment. Furthermore, a cellular line or a line based on IEEE 802.11 may be used as a backhaul. Whether or not the smartphone 900 operates as one of the APs in Multiple Serving AP MLD mode may be determined based on a user operation for enabling the AP function, or may be determined based on an operation other than the user operation for enabling the AP function.

[0191] Furthermore, the smartphone 900 may be provided with a biometric authentication unit (fingerprint authentication, palm shape authentication, voice authentication, blood vessel authentication, face authentication, iris authentication, retina authentication). In this case, the wireless communication interface 913 in which the communication control unit 111 and the control unit 130 in Fig. 3 are implemented is configured to receive power supply from the same battery 918 as at least one of the display device 910, the speaker 911, and the biometric authentication unit.

[0192] Furthermore, in the smartphone 900, information is displayed on at least one of the display device 910 and the speaker 911 based on communication with an external device via the wireless communication interface 913. At this time, information relating to the present technology may be output from at least one of the display device 910 and the speaker 911.

[0193] <Configuration Example of In-Vehicle Device> FIG. 20 is a block diagram showing an example of a schematic configuration of an in-vehicle device 920 to which the present technology is applied.

[0194] The in-vehicle device 920 is configured to include a processor 921, a memory 922, a GNSS (Global Navigation Satellite System) module 924, a sensor 925, a data interface 926, a content player 927, and a storage medium interface 928. The in-vehicle device 920 is also configured to include an input device 929, a display device 930, a speaker 931, a wireless communication interface 933, an antenna switch 934, an antenna 935, and a battery 938.

[0195] The processor 921 may be, for example, a CPU or an SoC, and controls the navigation function and other functions of the in-vehicle device 920. The processor 921 can also control the vehicle's driving system, such as the brake, accelerator, or steering, based on information obtained through communication based on the present technology.

[0196] The memory 922 includes RAM and ROM, and stores programs and data executed by the processor 921 .

[0197] The GNSS module 924 measures the position (e.g., latitude, longitude, and altitude) of the in-vehicle device 920 using GNSS signals received from GNSS satellites.

[0198] The sensor 925 includes a group of sensors such as a gyro sensor, a geomagnetic sensor, and an air pressure sensor.

[0199] The data interface 926 is connected to an in-vehicle network 941 via a terminal (not shown), for example, and acquires data generated on the vehicle side, such as in-vehicle data.

[0200] The content player 927 plays content stored on a storage medium (e.g., a CD or DVD) inserted into the storage medium interface 928. The storage medium interface 928 is an example of an external connection interface, and the storage medium is an example of an external storage medium.

[0201] The input device 929 includes, for example, a touch sensor that detects a touch on the screen of the display device 930, a button, or a switch, and accepts operations or information input from the user.

[0202] The display device 930 has a screen such as an LCD or OLED display, and displays information such as navigation functions or images of content being played, etc. The processor 921 also controls the display on the display device 930 based on information received via the first communication path and user operation of the input device 929.

[0203] The speaker 931 outputs the audio of the navigation function or the content being played.

[0204] Note that the navigation function and the function of the content player 927 are optional in the in-vehicle device 920. The navigation function and the content player 927 may be removed from the configuration of the in-vehicle device 920.

[0205] The wireless communication interface 933 supports one or more wireless LAN standards, such as IEEE 802.11a, 11b, 11g, 11n, 11ac, 11ad, 11ax, 11ay, 11be, 11bn, and successor standards thereof, and performs wireless communication. In infrastructure mode, the wireless communication interface 933 communicates with other devices via a wireless LAN AP. In ad hoc mode or a direct communication mode such as Wi-Fi Direct, the wireless communication interface 933 communicates directly with other devices. Note that, unlike ad hoc mode, in Wi-Fi Direct, one of two terminals operates as an AP, but communication is performed directly between the terminals.

[0206] The wireless communication interface 933 typically includes a baseband processor, an RF circuit, a power amplifier, etc. The wireless communication interface 933 may be a one-chip module that integrates a memory that stores a communication control program, a processor that executes the program, and related circuits. In addition to the wireless LAN system, the wireless communication interface 933 may support other types of wireless communication systems, such as a short-range wireless communication system such as Bluetooth, a proximity wireless communication system such as NFC, or a cellular communication system such as 2G, 3G, 4G, 5G, and 6G.

[0207] The antenna switch 934 switches the connection destination of the antenna 935 between multiple circuits included in the wireless communication interface 933 (for example, circuits for different wireless communication methods, or transmission system circuits and reception system circuits).

[0208] The antenna 935 has a single or multiple antenna elements and is used for transmitting and receiving wireless signals via the wireless communication interface 933. For example, when the antenna 935 has multiple antenna elements, it may have a second antenna element in addition to a first antenna element to form a MIMO (Multiple Input Multiple Output) antenna or an array antenna.

[0209] 20, the in-vehicle device 920 may include a plurality of antennas 935. In that case, the antenna switch 934 may be omitted from the configuration of the in-vehicle device 920.

[0210] In the in-vehicle device 920 shown in FIG. 20 , the battery 938 is connected via a power supply line partially indicated by a dashed line in the figure. For example, the communication control unit 111 and the control unit 130 shown in FIG. 3 may be implemented in the wireless communication interface 933. Furthermore, at least some of these functions may be implemented in the processor 921. The battery 938 is an example of a power sharing unit. The power sharing unit supplies power to the control unit 130, the processor 921, the input device 929, the display device 930, and the first and second antenna elements.

[0211] The wireless communication interface 933 may also operate as the above-described communication device and provide a wireless connection to a terminal owned by a user in the vehicle. For example, the wireless communication interface 933 may connect the in-vehicle device 920 to other peripheral devices, and the in-vehicle device 920 may use CarPlay (registered trademark) or Android Auto (registered trademark). Note that the wireless communication interface 933 may also connect the in-vehicle device 920 to other peripheral devices using a short-range wireless communication method, infrastructure mode, or a wireless LAN method using Wi-Fi Direct.

[0212] The in-vehicle device 920 may operate as a wireless AP (software AP) by having the processor 921 execute an AP function at the application level. The wireless communication interface 933 may also have a wireless AP function. The processor 921 or the wireless communication interface 933 may have a tethering function using a wireless LAN system and a cellular communication system, and may transmit payload data received via the cellular communication system via the wireless LAN system, or may transmit payload data received via the wireless LAN system via the cellular communication system. The in-vehicle device 920 may enable or disable its AP function based on a user setting operation. When the AP function is enabled, it may operate as AP MLD1 or AP MLD2 in the above-described embodiment. Furthermore, a cellular line or a line based on IEEE 802.11 may be used as a backhaul. Whether or not to operate as one of the APs in Multiple Serving AP MLD mode may be determined based on a user operation for enabling the AP function, or may be determined based on an operation other than the user operation for enabling the AP function.

[0213] Furthermore, the present technology may be realized as an in-vehicle system (or vehicle) 940 including one or more blocks of the above-described in-vehicle device 920, an in-vehicle network 941, and a vehicle-side module 942. The vehicle-side module 942 generates vehicle-side data such as vehicle speed, engine RPM, or fault information, and outputs the generated data to the in-vehicle network 941. The processor 921 or the wireless communication interface 933 may control any of the functions of the above-described embodiments based on the vehicle-side data acquired via the in-vehicle network 941. While the above description has been given using an example of a vehicle, the present technology may also be configured as peripheral equipment for other vehicles, such as a bicycle, a two-wheeled vehicle, personal mobility, an aircraft, or a ship.

[0214] <Configuration Example of Wireless AP> FIG. 21 is a block diagram showing an example of a schematic configuration of a wireless AP 950 to which the present technology is applied.

[0215] The wireless AP 950 includes a controller 951 , a memory 952 , an input device 954 , a display device 955 , a network interface 957 , a wireless communication interface 963 , an antenna switch 964 , and an antenna 965 .

[0216] The controller 951 may be, for example, a CPU or a DSP (Digital Signal processor) and operates various functions of the IP (Internet Protocol) layer and higher layers of the wireless AP 950 (e.g., access restriction, routing, encryption, firewall, and log management).

[0217] The memory 952 includes RAM and ROM, and stores programs executed by the controller 951 and various control information (for example, a terminal list, a routing table, an encryption key, security settings, and logs).

[0218] The input device 954 includes, for example, buttons and switches, and receives operations from the user. For example, the input device 954 may be configured to input a confirmation or response to information output from the display device 955. Furthermore, the input device 954 may be configured to input switching of the wireless function on / off and switching between the router function and the access point function, based on operations by the user.

[0219] The display device 955 includes an LED lamp or the like and displays information such as the operating status of the wireless AP 950. The display device 955 may also be configured as a projector that projects an output image onto a screen. A processor (not shown) controls the display on the display device 955 based on information received via the first communication path and a user's operation of the input device 954. The processor may also be implemented within the controller 951.

[0220] The network interface 957 is a wired communication interface for connecting the wireless AP 950 to a wired communication network 958. The network interface 957 may have multiple connection terminals. The network interface 957 may output payload data included in a wireless signal input from the wireless communication interface 963 as a wired signal, or may receive payload data output as a wireless signal from the wireless communication interface 963 as a wired signal. The network interface 957 may input and output wired signals in parallel with or independently of the wireless communication interface 963 inputting and outputting wireless signals. The wired communication network 958 may be a LAN such as Ethernet (registered trademark) or a WAN (Wide Area Network).

[0221] The wireless communication interface 963 supports one or more wireless LAN standards such as IEEE802.11a, 11b, 11g, 11n, 11ac, 11ad, 11ax, 11ay, 11be, 11bn or successor standards thereof, and provides wireless connection as an AP to nearby terminals.

[0222] The wireless communication interface 963 typically includes a baseband processor, an RF circuit, a power amplifier, and the like.

[0223] The wireless communication interface 963 may be a one-chip module that integrates a memory that stores a communication control program, a processor that executes the program, and related circuits.

[0224] The antenna switch 964 switches the connection destination of the antenna 965 among multiple circuits included in the wireless communication interface 963. The antenna 965 has a single antenna element or multiple antenna elements and is used for transmitting and receiving wireless signals via the wireless communication interface 963. For example, when the antenna 965 has multiple antenna elements, it has a second antenna element in addition to a first antenna element.

[0225] 21 , for example, the communication control unit 111 and the control unit 130 in FIG. 3 may also be implemented in the wireless communication interface 963. Furthermore, at least some of these functions may be implemented in the controller 951.

[0226] The above-described embodiment shows an example for realizing the present technology, and the matters in the embodiment correspond to the matters specifying the invention in the claims. Similarly, the matters specifying the invention in the claims correspond to the matters in the embodiment of the present technology having the same title. However, the present technology is not limited to the embodiment, and can be realized by applying various modifications to the embodiment without departing from the gist of the present technology.

[0227] Furthermore, part or all of the information processing device described in the above embodiments may be realized, for example, as a semiconductor chip (IC (Integrated Circuit)) having a wireless communication control function. Also, it may be realized by a single semiconductor chip equipped with multiple functions, such as a SoC (System on Chip), or by combining multiple semiconductor chips each having a single function, such as a processor. Furthermore, it may be realized by combining multiple SoCs, or by combining a semiconductor chip with a single function and a SoC. It may also be realized by a semiconductor chip such as an ASIC (Application Specific Integrated Circuit) dedicated to realizing each unit, or by a combination of a general-purpose processor with software or firmware, or by a semiconductor chip such as an FPGA (Field Programmable Gate Array).

[0228] Furthermore, the processing procedures described in the above embodiments may be regarded as a method having a series of these procedures, or as a program for causing this computer to execute these procedures or a recording medium for storing the program.

[0229] Examples of the recording medium that can be used include a CD (Compact Disc), an MD (MiniDisc), a DVD (Digital Versatile Disc), a memory card, and a Blu-ray (registered trademark) Disc.

[0230] In this specification, a system refers to a collection of multiple components (devices, modules (components), etc.), regardless of whether all of the components are contained in the same housing. Therefore, multiple devices housed in separate housings and connected via a network, and a single device housed in a single housing with multiple modules, are both systems.

[0231] Furthermore, the effects described in this specification are merely examples and are not limiting, and other effects may also be present.

[0232] The embodiments of the present technology are not limited to the above-described embodiments, and various modifications are possible without departing from the spirit of the present technology.

[0233] For example, the present technology can be configured as a cloud computing system in which a single function is shared and processed collaboratively by a plurality of devices via a network.

[0234] Furthermore, each step described in the above flowchart can be executed by one device, or can be shared and executed by a plurality of devices.

[0235] Furthermore, when one step includes multiple processes, the multiple processes included in that one step can be executed by one device or can be shared and executed by multiple devices.

[0236] This embodiment may also have the following configuration. [Notes] [Item 1] A communication control device including a control unit that controls communication of a first communication device, wherein the control unit controls the first communication device to transmit a first signal via a first communication path to a second communication device that is capable of communicating using multiple links simultaneously, and controls the first communication device to transmit a second signal including information regarding a transmission end time of the first signal to a third communication device that communicates with the first communication device via a second communication path or a third communication path. [Item 2] The communication control device according to item 1, wherein the information regarding the transmission end time of the first signal includes at least one of information specifying a transmission start time of the first signal and information specifying a length of a PPDU. [Item 3] The communication control device according to any one of items 1 and 2, wherein the information regarding the transmission end time of the first signal includes information indicating a period from a transmission end time of a frame in which the information is described to the transmission end time of the first signal. [Item 4] A communication control device comprising: a control unit that controls communication of a third communication device, wherein the control unit: controls the third communication device to transmit a third signal via a first communication path to a second communication device that is capable of communicating using multiple links simultaneously, controls the third communication device to receive a second signal from a first communication device that communicates with the third communication device via the second communication path or the third communication path, the second signal including information regarding a transmission end time of a first signal, and controls the third communication device to transmit the third signal to the second communication device so that the transmission time overlaps at least partially with the transmission of the first signal. [Item 5] The communication control device according to item 4, wherein the control unit: determines, from the information regarding the transmission end time of the first signal, whether it is possible to transmit the third signal so that transmission ends simultaneously with the first signal, and if it is possible to transmit the third signal, controls a length of the PPDU of the third signal and transmits the third signal.[Item 6] The communication control device according to any one of items 4 to 5, wherein the control unit determines, based on information regarding the transmission end time of the first signal, whether it is possible to transmit the third signal so that transmission ends simultaneously with the first signal, and if transmission of the third signal is not possible, the control unit transmits a fourth signal to a destination different from the destination of the third signal. [Item 7] The communication control device according to any one of items 1 to 6, wherein the third communication path is a link different from the link used for the first communication path. [Item 8] The communication control device according to any one of items 1 to 6, wherein the second communication path is a backhaul. [Item 9] The communication control device according to any one of items 4 to 6, wherein, if the control unit is unable to acquire information regarding the transmission end time of the first signal via the second communication path, the control unit requests the first communication device to retransmit information regarding the transmission end time of the first signal via the first communication path. [Item 10] The communication control device according to any one of items 1 to 6, wherein the control unit transmits information regarding the transmission end time of the first signal by including it in an RTS. [Item 11] The communication control device according to item 10, wherein the control unit transmits the first signal after receiving a CTS. [Item 12] The communication control device according to any one of items 1 to 11, wherein the control unit determines a transmission method of the first signal or a transmission method of information related to the transmission end time of the first signal based on information indicating a communication status in Multiple Serving AP MLD mode exchanged with the third communication device. [Item 13] The communication control device according to item 12, wherein the information indicating the communication status in Multiple Serving AP MLD mode includes information indicating a backhaul communication speed, information indicating whether communication is possible, information indicating an amount of delay, information indicating a degree of interference, or information indicating an error rate. [Item 14] The communication control device according to item 12, wherein the information indicating the communication status in Multiple Serving AP MLD mode includes information indicating whether the other communication device is within a range where wireless communication is possible.Item 15: The communication control device according to item 12, wherein the information indicating the communication status in the Multiple Serving AP MLD mode includes information indicating an occupancy rate per unit time of a channel included in each link. Item 16: The communication control device according to item 12, wherein the information indicating the communication status in the Multiple Serving AP MLD mode includes information indicating a Request, information indicating a Response, or information indicating a Confirm. Item 17: The communication control device according to item 13, wherein the control unit transmits the first signal by synchronizing start time with another communication device when the communication speed of the backhaul is equal to or less than a threshold. Item 18: The communication control device according to claim 13, wherein the control unit: transmits information related to a transmission end time of the first signal over the backhaul when the time required for information exchange over the backhaul is less than a predetermined first time; and transmits information related to the transmission end time of the first signal to the third communication device using the third communication path of the first communication path when the time required for information exchange over the backhaul is equal to or greater than the predetermined first time. [Item 19] The communication control device according to item 13, wherein the control unit determines to perform trigger base access when the communication speed of the backhaul is equal to or less than a threshold, transmits a trigger frame to the third communication device to perform start time synchronization with the third communication device, and transmits the first signal. [Item 20] The communication control device according to item 1, wherein the control unit determines not to share information regarding the transmission end time of the first signal based on information indicating a communication status in Multiple Serving AP MLD mode exchanged with the third communication device, and transmits the first signal with a no ack policy.[Item 21] The communication device according to any one of items 1 and 2, further comprising: a processor; an input device that accepts operations from a user; a display device; and a first antenna element, wherein the processor controls the display of the display device based on information received via the first communication path and the operation. [Item 22] The communication device according to item 21, further comprising: a speaker; an external connection interface for connecting to a memory card or a USB (Universal Serial Bus) device; a second antenna element that forms a MIMO antenna together with the first antenna element; and the power sharing unit that supplies power to the control unit, the processor, the input device, the display device, the second antenna element, and the external connection interface. [Item 23] The communication device according to item 21, further comprising: a content player that plays content stored on an external storage medium connected via the external connection interface. [Item 24] The communication device according to item 21, wherein the display device is an LED lamp that displays the operating status of the communication device. [Item 25] A first communication device including a communication control device, wherein the communication control device has a control unit that controls communication of the first communication device, and the control unit controls the first communication device to transmit a first signal via a first communication path to a second communication device that is capable of communicating using multiple links simultaneously, and controls the first communication device to transmit a second signal including information regarding the transmission end time of the first signal to a third communication device that communicates with the first communication device via a second communication path or a third communication path.[Item 26] A vehicle comprising a control unit that controls communication of a first communication device, wherein the control unit controls the first communication device to transmit a first signal via a first communication path to a second communication device that is capable of communicating by simultaneously using a plurality of links, and controls the first communication device to transmit a second signal, including information regarding a transmission end time of the first signal, to a third communication device that communicates with the first communication device, via the second communication path or a third communication path. [Item 27] ​​A wireless communication control method that controls communication of a first communication device, wherein the control unit controls the first communication device to transmit a first signal via the first communication path to a second communication device that is capable of communicating by simultaneously using a plurality of links, and controls the first communication device to transmit a second signal, including information regarding a transmission end time of the first signal, to a third communication device that communicates with the first communication device, via the second communication path or the third communication path. [Item 28] A program causing a computer to execute a wireless communication control method, comprising: controlling communication of a first communication device, the control comprising: controlling the first communication device to transmit a first signal via a first communication path to a second communication device capable of communicating by simultaneously using multiple links; and controlling the first communication device to transmit a second signal, including information regarding a transmission end time of the first signal, to a third communication device that communicates with the first communication device, via a second communication path or a third communication path. [Item 29] A non-transitory readable medium having recorded thereon a program causing a computer to execute a wireless communication control method, comprising: controlling communication of a first communication device, the control comprising: controlling the first communication device to transmit a first signal via the first communication path to a second communication device that can communicate by simultaneously using multiple links; and controlling the first communication device to transmit a second signal, including information regarding a transmission end time of the first signal, to a third communication device that communicates with the first communication device, via a second communication path or a third communication path.[Item 30] A communication control device comprising a control unit that controls communication of a second communication device that communicates via a first communication path using multiple links simultaneously, wherein the control unit receives a first signal from a first communication device, receives a third signal from a third communication device, and, after receiving the first signal and the third signal, controls to send a BA (Block Ack) to the first communication device and the third communication device. [Item 31] A wireless communication system comprising a first communication device, a second communication device, and a third communication device, wherein the first communication device comprises a first control unit that controls communication of the first communication device, the first control unit controls the first communication device to transmit a first signal to the second communication device that is capable of communicating using multiple links simultaneously via a first communication path, and controls the first communication device to transmit a second signal including information regarding a transmission end time of the first signal to a third communication device that communicates with the first communication device via a second communication path or a third communication path, the second communication device comprises a second control unit that controls communication of the second communication device that communicates using multiple links simultaneously via the first communication path, the second control unit receives the first signal from the first communication device, receives a third signal from the third communication device, and after receiving the first signal and the third signal, controls to transmit a BA (Block Ack) to the first communication device and the third communication device. [Item 32] The third communication device includes a third control unit that controls communication of the third communication device, and the third control unit controls the third communication device to transmit the third signal to the second communication device, controls the third communication device to receive the second signal from the first communication device that communicates with the third communication device via the second communication path, and controls the third communication device to transmit the third signal to the second communication device so that the transmission time overlaps at least partially with the transmission of the first signal.

[0237] 1, 2 AP MLD 3 SMD AP MLD 5 Router 100 Non-AP MLD 110 Communication unit 111 Communication control unit 112 Communication storage unit 113 Common data processing unit 121 Individual data processing unit 122 Signal processing unit 123 Wireless interface unit 124 Amplification unit 130 Control unit 140 Storage unit 150 Antenna 160 Wired interface unit 210 Communication unit 211 Communication control unit 212 Communication storage unit 213 Common data processing unit 221 Individual data processing unit 222 Signal processing unit 223 Wireless interface unit 224 Amplification unit 230 Control unit 240 Storage unit 250 Antenna 801 CPU 802 ROM 803 RAM 804 Bus 805 Input / output interface 806 Input unit 807 Output unit 808 Storage unit 809 Communication unit 810 Drive 811 Removable media 900 Smartphone 901 Processor 902 Memory 903 Storage 904 External connection interface 906 Camera 907 Sensor 908 Microphone 909 Input device 910 Display device 911 Speaker 913 Wireless communication interface 914 Antenna switch 915 Antenna 917 Bus 918 Battery 919 Auxiliary controller 920 In-vehicle device 921 Processor 922 Memory 924 GNSS module 925 Sensor 926 Data interface 927 Content player 928 Storage medium interface 929 Input device 930 Display device 931 Speaker 933 Wireless communication interface 934 Antenna switch 935 Antenna 938 Battery 940 In-vehicle system (or vehicle) 941 In-vehicle network 942 Vehicle-side module 951 Controller 952 Memory 954 Input device 955 Display device 957 Network interface 958 Wired communication network 963 Wireless communication interface 964 Antenna switch 965 Antenna

Claims

1. A communication control device comprising a control unit that controls communication of a first communication device, wherein the control unit controls the first communication device to transmit a first signal to a second communication device that is capable of communicating using multiple links simultaneously, via a first communication path, and controls the first communication device to transmit a second signal including information regarding the end time of transmission of the first signal to a third communication device that communicates with the first communication device, via a second communication path or a third communication path.

2. The communication control device according to claim 1, wherein the information relating to the transmission end time of the first signal includes at least one of information specifying the transmission start time of the first signal and information specifying the length of the PPDU.

3. A communication control device according to claim 2, wherein the information relating to the transmission end time of the first signal includes information indicating the period from the transmission end time of the frame in which the information is written to the transmission end time of the first signal.

4. A communication control device comprising a control unit for controlling communication of a third communication device, wherein the control unit: controls the third communication device to transmit a third signal to a second communication device capable of communicating using multiple links simultaneously via a first communication path; controls the third communication device to receive a second signal including information regarding the end time of transmission of a first signal from a first communication device that communicates with the third communication device via the second communication path or the third communication path; and controls the third communication device to transmit the third signal to the second communication device so that the transmission time overlaps at least partially with the transmission of the first signal.

5. The communication control device according to claim 4, wherein the control unit determines whether it is possible to transmit the third signal so that transmission ends simultaneously with the first signal, based on information relating to the end time of transmission of the first signal, and if it is possible to transmit the third signal, controls the length of the PPDU of the third signal and transmits the third signal.

6. The communication control device according to claim 5, wherein the control unit determines whether it is possible to transmit the third signal so that transmission ends simultaneously with the first signal, based on information relating to the end time of transmission of the first signal, and if it is not possible to transmit the third signal, the control unit transmits a fourth signal to a destination different from the destination of the third signal.

7. The communication control device according to claim 1, wherein the third communication path is configured using a link different from the link used in the first communication path.

8. The communication control device according to claim 1, wherein the second communication path is configured using a backhaul.

9. A communication control device as described in claim 4, wherein the control unit requests the first communication device to retransmit information regarding the transmission end time of the first signal via the third communication path if the control unit is unable to obtain information regarding the transmission end time of the first signal via the second communication path.

10. The communication control device according to claim 1, wherein the control unit transmits information relating to the transmission end time of the first signal by including it in the RTS.

11. The communication control device according to claim 10, wherein the control unit transmits the first signal after receiving a CTS.

12. The communication control device according to claim 1, wherein the control unit determines the method of transmitting the first signal or the method of transmitting information relating to the end time of transmission of the first signal based on information indicating the communication status in Multiple Serving AP MLD mode exchanged with the third communication device.

13. A communication control device as described in claim 12, wherein the information indicating the communication status in the Multiple Serving AP MLD mode includes information indicating the backhaul communication speed, information indicating whether communication is possible, information indicating the amount of delay, information indicating the degree of interference, or information indicating the error rate.

14. The communication control device according to claim 12, wherein the information indicating the communication status in the Multiple Serving AP MLD mode includes information indicating whether the third communication device is within a range where wireless communication is possible.

15. The communication control device according to claim 12, wherein the information indicating the communication status in the Multiple Serving AP MLD mode includes information indicating the occupation rate per unit time of the channels included in each link.

16. The communication control device according to claim 12, wherein the information indicating the communication status in the Multiple Serving AP MLD mode includes information indicating a Request, information indicating a Response, or information indicating a Confirm.

17. The communication control device according to claim 13, wherein the control unit transmits the first signal in start time sync with other communication devices when the communication speed of the backhaul is equal to or less than a threshold value.

18. The communication control device described in claim 13, wherein the control unit transmits information regarding the end time of transmission of the first signal via the backhaul when the time required for information exchange via the backhaul is less than a predetermined first time, and transmits information regarding the end time of transmission of the first signal to the third communication device using the third communication path among the first communication paths when the time required for information exchange via the backhaul is equal to or greater than the predetermined first time.

19. The communication control device according to claim 13, wherein the control unit, when the communication speed of the backhaul is equal to or less than a threshold, determines to perform trigger base access, transmits a trigger frame to the third communication device to perform start time sync with the third communication device, and transmits the first signal.

20. The communication control device described in claim 1, wherein the control unit determines not to share information regarding the transmission end time of the first signal based on information indicating the communication status in Multiple Serving AP MLD mode exchanged with the third communication device, and transmits the first signal with a no ack policy.

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