Wireless communication control device

Abstract

[Problem] To provide a wireless communication control device for continuing communication even when a QoS between an AP and a STA cannot be satisfied or even when the STA roams due to the circumstances on an AP side. [Solution] A wireless communication control device according to the present disclosure comprises a control unit that controls a wireless communication unit included in a first communication device and performing wireless communication with a second communication device in an autonomous decentralized wireless communication system via one or more access channels. The control unit determines whether to start connection switching processing for switching a connection switching destination of the second communication device from the first communication device to a third communication device. The connection switching processing includes processing for transmitting, to the third communication device, at least one of information pertaining to security between the first communication device and the second communication device or information pertaining to a state of data transmission.

Description

wireless communication control device

[0001] An embodiment of the present invention relates to a wireless 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), and an MLD is a logical entity that contains one or more STAs (Stations) 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 (Access Point), and an MLD in which each STA is a non-AP STA is called a non-AP MLD. To clarify that each entity within an MLD is an entity within the MLD, each entity is represented 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 non-AP MLD).

[0005] In use cases where multiple APs are installed, such as in homes and factories, it is necessary to provide low-latency, high-quality communications even when terminals move. To achieve this, IEEE 802.11bn is considering expanding the definition of MLD, which manages multiple APs within the same device, to define an entity that can collectively manage APs belonging to different devices (called roaming MLD in this document, but also known as Single Mobility Domain MLD (SMD MLD) or Ultra Fast Transition MLD (UFT MLD)). The operation of switching terminal connection destinations using this concept is called seamless roaming, and standardization is currently underway. The roaming MLD function can be executed on one of the AP devices or on a separate device.

[0006] Duncan Ho et al., “Seamless Roaming details,” IEEE 802.11-24 / 52r0, January 12, 2024.

[0007] In the system configuration shown in the previous contribution, when a STA switches connections (also called roaming), in normal operation, the STA sends a roaming request frame to initiate information transmission between APs. However, at the time of information transmission, the link quality between the AP and the STA may have already deteriorated, and QoS may not be met. In addition, there is a possibility that the STA may not be able to roam due to circumstances on the AP side.

[0008] In view of these problems, the present disclosure provides a wireless communication control device that continues communication even when QoS between the AP and the STA cannot be satisfied or when the STA cannot roam due to circumstances on the AP side.

[0009] The wireless communication control device of the present disclosure includes a wireless communication unit included in a first communication device, which is a control unit that controls the wireless communication unit that performs wireless communication with a second communication device in an autonomous and decentralized wireless communication system using one or more access channels, and the control unit determines whether to start a connection switching process to switch the connection switching destination of the second communication device from the first communication device to a third communication device, and the connection switching process includes a process of transmitting at least one of information regarding security and information regarding the status of data transmission between the first communication device and the second communication device to the third communication device.

[0010] 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 a backhaul in the wireless communication system in the first embodiment. FIG. 3 is a block diagram of a communication device including a wireless communication control device in the first embodiment. FIG. 4 is a block diagram of another communication device including a wireless communication control device in the first embodiment. FIG. 5 is a flowchart illustrating main operations of a source AP in the first embodiment. FIG. 6 is a flowchart illustrating main operations of a target AP in the first embodiment. FIG. 7 is a sequence diagram illustrating operation of connection switching in the first embodiment. FIG. 8 is another sequence diagram illustrating operation of connection switching in the first embodiment. FIG. 9 is an example format of power management information in the first embodiment. FIG. 10 is an example format of a roaming response frame in the first embodiment. FIG. 11 is a sequence diagram illustrating operation of connection switching in a comparative example. FIG. 12 is a sequence diagram illustrating operation of connection switching in the second embodiment. FIG. 13 is a sequence diagram illustrating operation of connection switching in the third embodiment. FIG. 14 is a sequence diagram illustrating operation of connection switching in the fourth embodiment. FIG. 15 is a block diagram illustrating an example hardware configuration of a computer that executes a series of processes according to the first to fourth embodiments by a program. FIG. 16 is a block diagram illustrating an example schematic configuration of a smartphone to which the first to fourth embodiments are applied. FIG. 17 is a block diagram illustrating an example schematic configuration of an in-vehicle device to which the first to fourth embodiments are applied. FIG. 18 is a block diagram illustrating an example schematic configuration of a wireless AP to which the first to fourth embodiments are applied.

[0011] 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.

[0012] 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.

[0013] First Embodiment FIG. 1 shows an example of the overall configuration of a wireless communication system according to a first embodiment.

[0014] The wireless communication system of FIG. 1 is an autonomous distributed control system including AP MLD 1, AP MLD 2, and non-AP MLD 100, for example, a wireless LAN wireless communication system conforming to the IEEE 802.11 standard, such as IEEE 802.11a / b / g / n / ac / ax / be / bn or its successor standards. The wireless communication system also includes a roaming MLD 3 that can manage APs in different communication devices. Each block in FIG. 1 is a logical entity. The wireless communication system of this embodiment illustrates an example in which communication is performed with the non-AP MLD 100 using AP MLDs 1 and 2. Hereinafter, the AP MLD and non-AP MLD are also referred to as communication devices. In the following description, an AP serving as a source AP is an example of a first communication device, and a non-AP STA is an example of a second communication device. An AP serving as a target AP is an example of a third communication device. The roaming MLD 3 is an example of a control device.

[0015] 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. That is, AP1-1 and AP1-2 exist within the same communication device, and AP2-1 and AP2-2 exist within the same communication device. STA1-1 and STA1-2 also exist within the same communication device. In this embodiment, the APs and STAs are described as being MLDs, but similar operations can also be performed for APs and STAs other than MLDs.

[0016] 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. In non-AP MLD 100, both link 1 and link 2 may be connected to AP MLD 1, both link 1 and link 2 may be connected to AP MLD 2, or link 1 and link 2 may be connected to different AP MLDs; however, in FIG. 1 , both link 1 and link 2 of non-AP MLD 100 are connected to AP MLD 1. In this example, the portion of the link connecting AP MLD 1 and non-AP MLD 100 indicated by the dashed-dotted line is called link 1, and the portion of the link connecting AP MLD 1 and non-AP MLD 100 indicated by the dashed-dotted line is called link 2.

[0017] A link refers to a physical path over which MAC service data units (MSDUs) can be transmitted between STAs. Links formed between different STAs are treated as different links. As described above, in the example of FIG. 1, link 1 and link 2 are different links. This diagram shows that non-AP MLD 100 is connected to AP MLD 1 via link 1 and link 2. Note that the connection between non-AP MLD and AP MLD is not limited to this case; non-AP MLD 100 may be connected to AP MLD 2 via both link 1 and link 2, or may be connected to AP MLD 1 via link 1 and AP MLD 2 via link 2.

[0018] The two links used in the wireless communication system of Figure 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 only one link, or three or more links. Furthermore, the number of AP MLDs to which non-AP MLD 100 connects is not limited to two, and may be one, or three or more. Furthermore, the above-mentioned links are examples of access channels.

[0019] Furthermore, the non-AP MLD 100 may switch the connection destination between APs operating on different channels by connection switching. For example, when the non-AP MLD 100 switches the connection destination from AP MLD 1 to AP MLD 2, the non-AP MLD 100 may be connected to each AP on a different channel.

[0020] Furthermore, the same encryption key may be used between AP MLD 1 and AP MLD 2 when switching the connection destination of non-AP MLD 100. In this case, AP MLD 1 and AP MLD 2 each encrypt their communications using the same encryption key.

[0021] Furthermore, AP-MLD1 and AP MLD2 are connected to roaming MLD3, which is an entity that collectively manages APs belonging to the wireless communication system, via a backhaul (corresponding to the dashed line portion in FIG. 1 ). Furthermore, roaming MLD3 is connected to a router (not shown) and is connected to a WAN such as the Internet. Furthermore, AP-MLD1 and AP MLD2 may communicate via a backhaul. Note that roaming MLD3 may be included in a communication device within the wireless communication system, such as MP MLD1 or 2. Furthermore, the form of connection with the entities is not limited to the example of FIG. 1 . For example, each AP MLD within the wireless communication system may be provided with roaming MLD3, and each roaming MLD3 may communicate via a backhaul.

[0022] 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 conforming to 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 Collision Avoidance) as the access method, and the AP MLDs 1 and 2 may transmit beacon signals at regular time intervals (periodically).

[0023] Furthermore, the AP MLDs 1 and 2 are devices that perform autonomous distributed control, and connection switching of the non-AP MLD 100 does not require connection to a core network device in the 3GPP standard or cellular network system.

[0024] The AP MLDs 1 and 2 and the non-AP MLD 100 may be NSTR (Non-Simultaneous TxRx) MLDs. Typically, whether the AP MLDs 1 and 2 and the non-AP MLD 100 are NSTR MLDs (NSTR capability) is determined in advance, such as during device design or manufacturing. 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 initiate a transmission operation on the other link. However, such a configuration is not necessary to realize this embodiment.

[0025] FIG. 2 is a diagram illustrating a specific example of a backhaul of the wireless communication system in the first embodiment.

[0026] 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 the same band as the link or a different band) 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 be composed 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 may be selected.

[0027] [Configuration Example of AP MLD 1] FIG. 3 is a block diagram of a communication device including a wireless communication control device in the first embodiment.

[0028] The operation of AP MLD1 will be explained with reference to Figure 3, but for non-AP MLD 100, AP can be read as STA, APx as STAx, and AP MLD Entity as STA MLD Entity, and differences from AP MLD1 will mainly be explained.

[0029] The communication device is mainly composed of a communication unit 110 (communication control unit 111, communication memory unit 112, data processing unit (individual data processing unit 121, common data processing unit 113)), signal processing unit 122, wireless interface unit 123, amplifier unit 124, control unit 130, memory unit 140, antenna 150, and backhaul communication unit 160. This communication device also has multiple APs inside, and these multiple APs are shown as APx. In this figure, one AP out of the multiple APs is illustrated and explained.

[0030] Of APx, AP1 or its AP MLD entity corresponds to a first wireless communication unit that performs communication regarding link 1 (first communication), and AP2 or its AP MLD entity corresponds to a second wireless communication unit that performs communication regarding link 2 (second communication). Similarly, APX or its AP MLD entity corresponds to an Xth wireless communication unit that performs communication regarding link X (X is an integer of 1 or more) (Xth communication). Furthermore, the first to Xth wireless communication units are each examples of a wireless communication unit.

[0031] The communication control unit 111 controls the operation of each unit and the transmission of information between each unit so that each unit performs wireless communication in an autonomous distributed control type wireless communication system, for example, a wireless LAN wireless communication system conforming to the IEEE802.11 standard such as IEEE802.11a / b / g / n / ac / ax / be / bn or its successor standards. The communication control unit 111 also controls the transfer of control information and management information to be notified to other communication devices to each data processing unit.

[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 and data received.

[0033] During transmission, the data processing unit 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 and the like to generate data units, performs channel access operations based on carrier sense, adds 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, the data processing unit performs processing to unconcatenate the MAC headers of received data units, analyzes and detects errors, requests retransmission, and decrypts and reorders the data units. The data processing unit may be 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] In this embodiment, the common data processing unit 113 is also referred to as AP MLD / non-AP MLD. In particular, in an AP, the common data processing unit 113 may have two blocks: a block (AP MLD) dedicated to this communication device and a shared block (roaming MLD) that can communicate with other communication devices. The AP may not have the common data processing unit 113. In this case, processing is performed by the common data processing unit 113 of another communication device. Even if the communication device has the common data processing unit 113, the communication device may operate so that processing is performed by the common data processing unit 113 in another communication device, rather than by its own processing unit. Furthermore, the AP MLD / non-AP MLD may be composed of not only the common data processing unit 113 but also part of the communication control unit 111 and the communication storage unit 112.

[0035] The signal processing unit 122 includes a transmission signal processing unit and a reception signal processing unit. The transmission signal processing unit performs encoding, interleaving, modulation, etc. on the data unit, adds a physical header, and generates a symbol stream. The reception signal processing unit analyzes the physical header, and performs demodulation, deinterleaving, decoding, etc. on the symbol stream to generate a data unit. It also estimates complex channel characteristics and performs spatial separation processing as needed. In this embodiment, the signal processing unit 122 is also called a PHY unit.

[0036] The radio interface unit 123 includes a transmitting radio interface unit and a receiving radio interface unit. The transmitting radio 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 radio interface unit performs down-conversion, filtering, and analog-to-digital signal conversion on the received signal to generate a symbol stream.

[0037] The amplifier unit 124 includes a transmission amplifier unit and a reception amplifier unit. The transmission amplifier unit amplifies a signal input from the transmission wireless interface unit. The reception amplifier unit amplifies a signal input from the antenna. A part of the amplifier unit may be a component outside the communication unit. Also, a part of the amplifier unit may be included in the wireless interface unit. In this embodiment, the wireless interface unit and amplifier unit 124 are collectively referred to as an RF unit.

[0038] The control unit 130 controls the communication unit 110, the communication control unit 111, and the backhaul communication unit 160. The control unit 130 may also perform part of the operation of the communication control unit 111. The communication control unit 111 and the control unit 130 may be configured as a single block. The wireless communication control device according to the present disclosure is, for example, a chip realized by one or more LSIs. The control unit of the wireless 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 wireless 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 APx.

[0039] The storage unit 140 holds information used by the control unit 130 and the communication unit 110. It 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.

[0040] The wireless interface unit 123, the amplifier unit 124, and the antenna 150 may be grouped together, and two or more groups may be components of a communication device. The data processing unit and the signal processing unit may be grouped together, and two or more groups may be connected to one wireless interface unit 123.

[0041] Backhaul communication unit 160 decodes the packets acquired from the backhaul and passes them to communication unit 110 via control unit 130. Note that non-AP MLD does not necessarily have to have the function of backhaul communication unit 160.

[0042] The communication unit 110 can be realized by one or more LSIs. Note that the configuration of the communication unit 110 is an example and is not limited to this. For example, the communication unit 110 can be configured with three or more blocks. Furthermore, when the communication unit 110 is configured with three or more blocks, some of the blocks can share the same antenna via an antenna switch.

[0043] [Configuration Example of Non-AP MLD 100] FIG. 4 is a block diagram of another communication device including the radio communication control device in the first embodiment.

[0044] The basic configuration of a communication device (here, non-AP MLD 100 is taken) is the same as that of AP MLD 1. Non-AP MLD 100 is composed of a communication unit 210 (communication control unit 211, communication memory unit 212, data processing unit (individual data processing unit 221, common data processing unit 213), signal processing unit 222, wireless interface unit 223, amplifier unit 224, control unit 230, memory unit 240, and antenna 250. This communication device also has multiple APs internally, and these multiple APs are indicated as APx. Also, unlike AP MLD 1, non-AP MLD 100 does not have a backhaul communication unit 160.

[0045] FIG. 5 is a flowchart illustrating the main operation of the source AP in the first embodiment.

[0046] In this flowchart, AP MLD1 will be taken as the source AP that is the source of connection switching, and AP MLD2 will be taken as the target AP that is the destination of connection switching, in the wireless communication system of Figure 1. The STA to which connection switching is performed will be described as a non-AP MLD 100. This flowchart also illustrates an example in which the AP MLD 1 determines whether to perform connection switching of the STA based on information related to the QoS of the link established between the AP MLD 1 and the non-AP MLD 100 and the power management information (also referred to as Power Management Info) of the own device.

[0047] This flowchart describes an example in which the connection destination of non-AP MLD 100 is switched based on a decision made by AP MLD 1, rather than based on a roaming request frame transmitted from non-AP MLD 100. Although omitted from this flowchart, when AP MLD 1 receives a roaming request frame from non-AP MLD 100, it switches the connection in the same way as a normal AP operates. The decision to switch the connection may be made by roaming MLD 3 or AP MLD 2, rather than AP MLD 1. In other words, the decision on whether to switch the connection of non-AP MLD 100 may be made under the control of a control unit included in roaming MLD 3 or AP MLD 2. The same applies to the following examples.

[0048] In step S1, the control unit 130 of the AP MLD 1 controls the communication unit 110 to acquire communication environment information. The control unit 130 of the AP MLD 1 controls the acquisition of communication environment information, such as information about the backhaul connecting the AP MLD 1 and the AP MLD 2, information about the non-AP MLD 100, information about the AP MLD buffer capacity, information about APs that are candidates for connection destination switching, and information about whether the present embodiment is supported. For example, this information is acquired through communication with a router located in the backhaul. Examples of backhaul information include information about the line type (wired or wireless), information about the communication status (e.g., whether communication is possible, information about the communication speed, information about the amount of delay, information about the degree of interference, and information about the error rate). Examples of information about the non-AP MLD 100 include the amount of data buffered in the non-AP MLD 100 and information about simultaneous transmission and reception on multiple links. Examples of information about simultaneous transmission and reception on multiple links include the number of radios or the NSTR capability. Information about the AP / AP MLD buffer capacity includes, for example, information about the buffer capacity of an AP or AP MLD located in the wireless communication system. The information about APs that are candidates for connection switching is, for example, the amount of buffered data held by the candidate APs, or the formation status of the Stream Classification Service (SCS) streams of these APs, or information about R-TWT (Restricted Target Wake Time). The information about whether or not the present embodiment is supported is information about whether or not control to maintain communication by performing connection switching based on the communication status between the AP MLD1 and the non-AP MLD 100, or control to maintain communication based on the communication schedule of the AP MLD1, is supported. For example, the control unit 130 of the AP MLD1 can determine the connection destination after switching from among the candidate APs that are compatible with the present embodiment. This information may be written in the Multi-Link element.

[0049] In step S2, the control unit 130 of the AP MLD 1 controls the communication unit 110 to collect information about the communication status with the non-AP MLD 100 and information about the communication schedule of the AP MLD 1's own device. The control unit 130 of the AP MLD 1 collects this information by communicating with the non-AP MLD 100 and the roaming MLD 3. For example, regarding information about the communication status with the non-AP MLD 100, the control unit 130 of the AP MLD 1 receives information about the QoS of the link between the two devices, such as QoS characteristic element information and an R-TWT membership setup request, from the non-AP MLD 100. The control unit 130 of the AP MLD 1 also collects information about the communication schedule, such as power management information about a schedule for transitioning to a power saving mode, from the roaming MLD 3. QoS is an example of information about communication quality. The information about communication quality may also be other information for maintaining communication quality.

[0050] In step S3, the control unit 130 of AP MLD1 determines whether or not to perform connection switching of the non-AP MLD 100. If the characteristic element received in step S2 is not satisfied as the QoS requirement of the non-AP MLD 100, the control unit 130 of AP MLD1 determines to perform connection switching (Yes in step S3), and determines a target AP that satisfies the QoS requirement of the non-AP MLD 100 from information about candidate APs for connection switching, obtained as communication environment information. In this example, the control unit 130 of AP MLD1 determines AP MLD2 as the target AP. If the non-AP MLD 100 is forming an SCS stream, the control unit 130 of AP MLD1 may add target AP information (target AP info) to an SCS response frame and transmit it, and start switching the non-AP MLD 100. Furthermore, when the non-AP MLD 100 is in the process of setting up an R-TWT membership, the control unit 130 of the AP MLD 1 may add information about the target AP to the broadcast TWT element and transmit it, thereby starting switching of the non-AP MLD 100. The QoS request is an example of a request for communication quality.

[0051] Furthermore, when the control unit 130 of the AP MLD1 determines to switch the connection of the non-AP MLD 100 based on its own power management information, such as when the control unit 130 is scheduled to transition to the Doze state, a power-saving mode, and the control unit 130 notifies the control unit 130 of the non-AP MLD 100 of the time until transition to the Doze state, the Doze state duration, and the AP with which the non-AP MLD 100 will communicate during the Doze state, using a Beacon frame. The AP with which the non-AP MLD 100 will communicate during the Doze state may be determined based on information about candidate APs for the connection switching destination, as described above. Note that Beacon frames are transmitted at predetermined intervals, and this information may be transmitted at any of these intervals. Furthermore, when the time until the AP MLD 1 transitions to the Doze state is equal to or shorter than a predetermined first threshold, the control unit 130 of the AP MLD 1 may operate to provide a transmission opportunity to the source AP through cooperation between APs, such as C-TDMA (Coordinated TDMA). This allows the control unit 130 of the AP MLD 1 to send all of the data buffered in the control unit 130, even if the time until the transition to the Doze state is short.

[0052] Furthermore, if the control unit 130 of the AP MLD1 cannot find an AP that satisfies the QoS requirements of the non-AP MLD 100 from the information about candidate APs for connection switching, acquired as communication environment information, it determines not to perform connection switching (No in step S3). Furthermore, if it cannot find another AP to which the non-AP MLD 100 can connect, it similarly determines not to perform connection switching, and the control unit 130 of the AP MLD 1 cancels the transition of its own device to the Doze state and continues communication with the non-AP MLD 100.

[0053] In step S4, the control unit 130 of the AP MLD 1 transmits information (also referred to as "context") related to the connection with the STA to the target AP. The information related to the connection with the STA includes one or both of the following: information related to the security of the connection between the source AP and the non-AP MLD 100, such as a Group Temporal Key (GTK) or a Pairwise Transient Key (PTK), and information related to the status of data transmission between the AP MLD 1 and the non-AP MLD 100, such as a sequence number (SN) or a packet number (PN), i.e., information related to the receipt confirmation of the data. The information related to the data transmission status may be information related to scoreboard management, such as a Traffic Identifier (TID) or information specifying the receipt confirmation window (WinStart), or may include both the sequence number (SN) or the packet number (PN) and information related to scoreboard management. The information related to the connection with the STA may also include association information. The information related to the connection with the STA may be transmitted via a backhaul or may be transmitted by being included in a Beacon frame. If an external device connected to the source AP and the target AP, such as roaming MLD3, collectively manages the above information, this step may be skipped.

[0054] FIG. 6 is a flowchart illustrating the main operation of the target AP in the first embodiment.

[0055] This flowchart mainly explains the operational flow when AP MLD2, which is the target AP, receives information regarding the connection with the STA from AP MLD1, which is the source AP, and notifies non-AP MLD100, which is also the STA, that reception of this information has been completed.

[0056] In step S21, the control unit 130 of the AP MLD 2 controls the communication unit 110 to acquire communication environment information. The communication environment information acquired in this step controls to acquire information similar to that described above, such as information on the backhaul connecting the AP MLD 1 and AP MLD 2, information on the non-AP MLD 100, information on the buffer capacity of the AP / AP MLD, information on APs that are candidates for connection destination switching, and information on whether or not the present embodiment is supported.

[0057] In step S22, the control unit 130 of the AP MLD 2 receives information about the connection with the STA from the AP MLD 1. The information about the connection with the STA acquired in this step includes the same information as described above, such as information about security and information about the status of data transmission between the AP MLD 1 and the non-AP MLD 100. If an external device connected to the source AP and target AP, such as the roaming MLD 3, collectively manages the above information, this step may be skipped.

[0058] Alternatively, rather than the AP MLD1 (the source AP) making the decision, the control unit 130 of the AP MLD2 (the target AP) may determine to switch the connection from AP MLD1 to its own device to non-AP MLD100. In this case, the control unit 130 of AP MLD2 may request the source AP to transmit information regarding the connection with the STAs. For example, AP MLD2 determines to switch the connection of non-AP MLD100 if the value of the radio wave strength (RSSI: Received Signal Strength Indicator) measured when receiving a frame from non-AP MLD100 is greater than the value of AP MLD1, or if the number of STAs connected under AP MLD2 is less than the number of STAs connected under AP MLD1. Furthermore, AP MLD2 may determine to switch the connection of non-AP MLD100 based on the results of a comparison of communication quality, such as when the quality of the link between AP MLD1, AP MLD2, and non-AP MLD100 is better or is expected to be better than the quality of the link between non-AP MLD100. In addition, AP MLD2 may determine to perform connection switching of non-AP MLD100 based on the results of comparing the communication schedules, for example, if the transition period to power saving mode of its own device is later than the transition period to power saving mode of AP MLD1, or if it is known that AP MLD1 will soon transition to power saving mode.

[0059] After the AP MLD 2 has completed receiving information regarding the connection with the STA, in step S23 the AP MLD 2 notifies the non-AP MLD 100 that communication between the two devices has become possible. The information notified from the AP MLD 2 to the non-AP MLD 100 includes, for example, the GTK, AID (Association ID), the MAC address of the AP MLD 2, capability related to whether communication is possible, and information used for QoS control such as SCS, TWT, or R-TWT.

[0060] FIG. 7 is a sequence diagram illustrating the operation of connection switching in the first embodiment.

[0061] In this sequence diagram, AP MLD1 is used as the source AP that is the source of connection switching in the wireless communication system of Figure 1, and AP MLD2 is used as the target AP that is the destination of connection switching. The STA to which connection switching is performed is described as non-AP MLD100. This example also outlines a sequence in which AP MLD1 determines to perform connection switching for the STA based on its own power management information. At the start of the sequence, AP MLD1, which is the source AP, and non-AP MLD100, which is the STA, form a link between AP1-1 and STA1-1. After the connection switching, AP MLD2, which is the target AP, and non-AP MLD100 form a link between AP2-1 and STA1-1.

[0062] In this sequence diagram, it is assumed that the source AP and the target AP have each acquired communication environment information, and that the source AP has acquired its own power management information.

[0063] The control unit 130 of AP MLD1 determines to transition to Doze state based on its own power management information, and transmits a Beacon frame from AP1-1 to notify STA1-1 of the Doze state period before transitioning to Doze state. The control unit 130 of AP MLD1 also notifies STA1-1 that the AP with which non-AP MLD100 communicates during Doze state, i.e., the AP to which connection is switched, is AP MLD2.

[0064] For example, when transmitting a Beacon frame or establishing a connection with a STA, the control unit 130 of AP MLD1 may transfer to AP MLD2 information regarding the connection with the STA that does not change during communication, such as PTK (also called static context).

[0065] When transitioning to the Doze state, the control unit 130 of the AP MLD1 transfers to AP2-1 information relating to the connection with the STA, including information relating to data transmission with the non-AP MLD 100, such as the latest SN and PN (also referred to as dynamic context). At this time, the control unit 130 of the AP MLD1 may transfer all or part of the data addressed to the non-AP MLD 100 that remains in the buffer of the AP MLD1 to AP2-1. Furthermore, the timing of transmitting the static context and dynamic context is an example. For example, the static context may be transmitted together with the dynamic context, or this information may be transmitted at other times.

[0066] When the control unit 130 of AP MLD2 has completed receiving the dynamic context from AP MLD1 and has completed changing the DS mapping, AP2-1 transmits a roaming response frame to STA1-1 notifying that connection switching has been completed. Alternatively, the control unit 130 of AP MLD2 may omit the operation of transmitting the roaming response frame and transmit a data frame from AP2-1 to STA1-1. The roaming response frame is also referred to as a response to connection switching.

[0067] Furthermore, after receiving the roaming response frame, the control unit 230 of the non-AP MLD 100 may transmit a roaming request frame from STA1-1 to AP1-1 or AP2-1 if it has not received static context via a Beacon frame or the like. For example, the control unit 230 of the non-AP MLD 100 may inquire of these APs about static context, which is part of the information related to the connection with the STA. Furthermore, if the control unit 230 of the non-AP MLD 100 determines to switch to another AP MLD instead of AP2-1, for example, if the communication environment has changed since the Beacon frame was received, it may transmit a roaming request frame to AP1-1. Furthermore, if it determines that connection switching is unnecessary due to the movement status of the non-AP MLD 100, for example, if the non-AP MLD 100 makes a round trip and returns to the original AP, the control unit 230 of the non-AP MLD 100 may transmit a roaming request frame to AP1-1 to indicate that connection switching will not be performed.

[0068] Furthermore, when the communication unit 110 of AP MLD1 receives from non-AP MLD 100 a roaming request frame specifying an AP MLD as the target AP that is different from the target AP specified when transmitting a Beacon frame, the control unit 130 of AP MLD1 may change the connection switching destination to that AP MLD based on the traffic conditions and the time required for the non-AP MLD 100 to transfer information regarding connection with the STA to the AP MLD to which it is requesting connection. In this case, the control unit 130 of AP MLD1 transmits a dynamic context to that AP MLD.

[0069] FIG. 8 is another sequence diagram illustrating the connection switching operation in the first embodiment.

[0070] In this sequence diagram, as with the above, AP MLD1 will be used as the source AP that is the source of the connection switchover, and AP MLD2 will be used as the target AP that is the destination of the connection switchover. The STA to which the connection switchover is performed will be described as a non-AP MLD 100. This example will outline a sequence in which AP MLD1 determines to perform connection switchover of the non-AP MLD 100 based on the SCS stream formation status among information about the QoS of the link established between AP MLD1 and the non-AP MLD 100. At the start of the sequence, AP MLD1, which is the source AP, and non-AP MLD 100, which is the STA, form a link between AP1-1 and STA1-1, and after the connection switchover, AP MLD2, which is the target AP, and non-AP MLD 100 form a link between AP2-1 and STA1-1.

[0071] In addition, in this sequence diagram, it is assumed that AP MLD1 and the target AP have acquired communication environment information, and that AP MLD1 determines that the QoS characteristic received from non-AP MLD 100 cannot satisfy the QoS requirements, and transmits an SCS response including information about AP MLD2, which is the target AP.

[0072] The control unit 130 of AP MLD1 controls the communication unit 110 to include information about AP MLD2 as a target AP that satisfies the QoS requirements in an SCS response and transmit this response from AP1-1 to STA1-1. Furthermore, when R-TWT membership is set in the non-AP MLD 100 and the control unit 130 of AP MLD1 determines to perform connection switching based on this information, it transmits the AP MLD2 information in a broadcast TWT element. Furthermore, when starting connection switching, the control unit 130 of AP MLD1 transmits information about the connection with the STA to AP2-1.

[0073] When the control unit 130 of AP MLD2 has completed receiving information about the connection with the STA from AP MLD1 and has completed changing the DS mapping, it transmits a roaming response frame from AP2-1 to STA1-1 notifying that the connection switching has been completed.Alternatively, the control unit 130 of AP MLD2 may omit the operation of transmitting the roaming response frame and transmit a data frame from AP2-1 to STA1-1.

[0074] FIG. 9 shows an example of the format of the power management information in the first embodiment.

[0075] In this embodiment, an example will be described in which power management information is included in a Multi-link element (for example, included as a Power Management Info field in the last two octets) and transmitted. This format is an example, and the power management information may be included in other information, such as a PHY header or a MAC header, rather than in the Multi-link element. Furthermore, the names and contents of each field below are examples, and other names and contents may be used.

[0076] In the Power management Info field, the Power Management field describes the power management mode that indicates the operating state of the AP. The power management mode may include information such as Active, which indicates that the AP is in the Active state rather than the power saving mode, or information such as Scheduled PS, which indicates that the AP is in the scheduled power saving mode, or Unscheduled PS, which indicates that the AP is in the unscheduled power saving mode. The Wakeup Delay field describes information that indicates the delay time required to return from the power saving mode. For example, the Wakeup Delay field describes the delay time required to transition to the active state after receiving a wakeup signal from the STA, which is a signal indicating that the AP will return from the Doze state to the Active state.

[0077] The Start time contains the time until the device transitions to the Doze state. The Duration contains the duration of the Doze state. The Target AP Info contains information about the AP to connect to in the Doze state.

[0078] FIG. 10 shows an example of the format of a roaming response frame in the first embodiment.

[0079] In this embodiment, an example is shown in which a roaming response frame is described as an element. The names and contents of each field below are merely examples, and other names and contents may be used. Also, the field does not have to be described as an element, and may be included in other information, such as a PHY header or a MAC header.

[0080] The identifier of this element is described in Element ID. The length of this element is described in Length. The identifier of this element is described in Element ID Extension.

[0081] The Target AP MAC address describes the MAC address of the target AP. The Target AP MAC address may describe the MAC address of the source AP in addition to the MAC address of the target AP. The Target AP Capability describes information indicating the capability of the target AP. The information described in the EHT Capabilities element or part of it may be described. The Target AP QoS describes information related to QoS control with the connection switching destination AP. For example, information used for SCS Stream formation or R-TWT membership setup is described as information related to QoS control.

[0082] In the present embodiment, an example has been described in which roaming is performed based on the judgment of the AP, i.e., initiated by the AP (also referred to as AP initiated). However, the STA may determine its own communication status and send a roaming request frame to the AP, i.e., initiate connection switching initiated by the STA (STA initiated seamless roaming). These connection switching methods may also be used depending on the situation. For example, if the AP does not perform power management, connection switching may always be performed based on a roaming request frame from the STA. Furthermore, if the AP is a mobile AP, STA initiated seamless roaming may be primarily used to reduce AP processing. For example, when AP MLD1 receives a roaming request from non-AP MLD100, the control unit 130 determines to perform connection switching of the non-AP MLD100 and controls the transmission of information regarding the connection with the STA to AP MLD2, which is the target AP.

[0083] Furthermore, the AP MLD 1 may be configured to accept on / off input from a user for AP initiated and STA initiated operations, allowing the AP MLD 1 to selectively use these modes. For example, a user may connect the AP MLD 1 to a PC (Personal Computer) and set these functions on or off via a user interface displayed on the PC, with the control unit 130 of the AP MLD 1 controlling the use of these modes depending on the on / off state. The mode in which the control unit 130 switches the connection of the non-AP MLD 100 by AP initiated is called a first operation mode, and the operation mode in which the control unit 130 switches the connection of the STA by STA initiated is called a second operation mode.

[0084] Furthermore, the AP MLD 1 may notify the non-AP MLD 100 and the AP MLD 2 of the on / off states of the first and second operation modes, for example, by a Beacon frame. Furthermore, when the second operation mode is in the off state, the control unit 230 of the non-AP MLD 100 that has received the notification may perform control not to transmit a roaming request frame to the AP MLD 1.

[0085] FIG. 11 is a sequence diagram illustrating the operation of connection switching in the comparative example.

[0086] This sequence diagram explains the operation of switching the connection destination of the non-AP MLD 100 (STA) from the source AP AP MLD 1 to the target AP AP MLD 2 based on the control of the controller. The vertical axis represents time, and the horizontal axis represents data exchange between devices. The left part of the diagram also shows data transmitted in UL and DL communications by the STA. In this diagram, the controller refers to the entity that implements roaming UMAC, which manages AP MLD 1 and AP MLD 2.

[0087] In sequence 1, a link is formed between the non-AP MLD 100 and the AP MLD 1 based on control by the controller. In sequence 2, the non-AP MLD 100, which is an STA, decides to start connection switching. For example, the start of connection switching is decided depending on the signal strength received from AP 1 as the non-AP MLD 100 moves. In sequence 3, the non-AP MLD 100 outputs an MPDU that has not yet been processed on the AP MLD 1. In sequence 4, the non-AP MLD 100 transmits a roaming announcement indicator (RAI) and requests the AP MLD 1 to switch its connection destination. In sequence 5, the AP MLD 1 transmits information regarding the connection with the STA to the AP MLD 2. In sequence 6, based on the information regarding the connection with the STA, the data path between the non-AP MLD 100 and the AP MLD 1 is switched to the data path between the non-AP MLD 100 and the AP MLD 2.

[0088] In sequence 7, DL data is transmitted from a higher-level device such as a controller. In sequence 8, a roaming announcement response is transmitted from the AP MLD 1 to the non-AP MLD 100, completing the switching of the data path. In sequence 9, UL (uplink) data and DL (downlink) data are communicated using the switched data path.

[0089] In this sequence, when a STA switches its connection, the STA sends a roaming request frame, which starts information exchange between the APs. However, when information exchange starts between the AP and the STA, the link quality may have already deteriorated and QoS may not be met, or the AP may be unable to start the connection switch properly due to circumstances such as a plan to transition to the Doze state by power management.

[0090] According to this embodiment, the AP determines whether to switch the connection of the STA based on information about the power management of the AP itself. As a result, even if the AP is scheduled to transition to the Doze state by power management, the connection destination of the STA can be appropriately switched, and communication can be continued.

[0091] Furthermore, according to this embodiment, the AP determines whether to switch the connection of the STA based on information about the QoS of the link between the AP and the STA. As a result, even if the AP cannot satisfy the QoS request from the STA, the AP can switch the connection to another AP and continue communication.

[0092] Second Embodiment FIG. 12 is a sequence diagram illustrating a connection switching operation in a second embodiment.

[0093] In this embodiment, the overall configuration of the communication devices in the wireless communication system and the block diagram of each communication device are the same as those in the first embodiment, and therefore will not be described again. Also, in this sequence diagram, as in the above, AP MLD1 will be used as the source AP that is the source of connection switching, and AP MLD2 will be used as the target AP that is the destination of connection switching. Also, the STA to which connection switching is performed will be described as a non-AP MLD 100.

[0094] In this sequence diagram, it is assumed that the source AP and the target AP have each acquired communication environment information, and that the source AP has acquired its own power management information.

[0095] For example, if the time until the source AP transitions to the Doze state is short, or due to reasons such as backhaul bandwidth pressure, the control unit 130 of AP MLD1 may not be able to complete transmission of information regarding connections with all STAs to the target AP. In this embodiment, an example will be taken up in which AP MLD2 is unable to receive some of the information in the Dynamic context transmitted from AP MLD1 to AP MLD2 before switching, and a sequence for continuing the connection switching operation will be described.

[0096] Furthermore, when the control unit 130 of AP MLD1 determines to switch the connection of non-AP MLD100 based on the power management information of its own device, such as when the device is scheduled to transition to Doze state, it notifies STA1-1, for example, by a Beacon frame, of the time until transition to Doze state, the duration of Doze state, and the AP with which non-AP MLD100 will communicate during Doze state.

[0097] For example, when transmitting a Beacon frame or establishing a connection with a STA, the control unit 130 of the AP MLD1 may transfer the static context, which is part of the information relating to the connection with the STA, to the AP2-1.

[0098] When transitioning to the Doze state, the control unit 130 of the AP MLD1 transfers the dynamic context, which is part of the information related to the connection with the STA, to the AP2-1. At this time, the control unit 130 of the AP MLD1 may transfer to the AP2-1 the data addressed to the non-AP MLD 100 that remains in the buffer of the AP MLD1, or part of the data. The transmission timing of the static context and the dynamic context is an example. For example, the static context may be transmitted together with the dynamic context, or this information may be transmitted at other timings.

[0099] If all information of the dynamic context has been received at the time of completion of switching, the control unit 130 of AP MLD2 transmits a roaming response frame from AP2-1 to STA1-1 notifying that connection switching has been completed. Alternatively, the control unit 130 of AP MLD2 may omit the operation of transmitting the roaming response frame and transmit a data frame from AP2-1 to STA1-1.

[0100] Furthermore, if the control unit 130 of the AP MLD 2 is unable to receive all of the information in the dynamic context at the time of completion of switching, it may request the non-AP MLD 100 to transmit the information that has not been received by a roaming response (request for context). Furthermore, the information specifying the information that has not been received may include, for example, an SN that has already been received or a PN that has already been received.

[0101] Upon receiving a roaming response frame including a context request, the non-AP MLD 100, under the control of the control unit 230, includes the dynamic context according to the request in a roaming response ack frame and transmits the frame to the AP MLD 2. The ack transmitted at this time may be a normal ack frame to which information regarding the connection with the AP has been added. Furthermore, if the context request includes a request to transmit not only the dynamic context but also the static context, the non-AP MLD 100 transmits this information to the AP MLD 2 as well.

[0102] According to this embodiment, even if the source AP can only complete sending part of the information regarding the connection with the STA, the target AP can request a context from the non-AP MLD 100 and the missing information can be supplemented, thereby appropriately switching the connection and continuing communication.

[0103] Third Embodiment FIG. 13 is a sequence diagram illustrating a connection switching operation in a third embodiment.

[0104] In this embodiment, the overall configuration of the communication devices in the wireless communication system and the block diagram of each communication device are the same as those in the first embodiment, and therefore will not be described again. Also, in this sequence diagram, as in the above, AP MLD1 will be used as the source AP that is the source of connection switching, and AP MLD2 will be used as the target AP that is the destination of connection switching. Also, the STA to which connection switching is performed will be described as a non-AP MLD 100.

[0105] In this sequence diagram, it is assumed that the source AP and the target AP have each acquired communication environment information.

[0106] It is also possible that the AP MLD 1 suddenly transitions to the power saving mode, rather than according to the schedule determined in the power saving mode transition schedule. In this embodiment, an example is taken up in which the AP MLD 1 transitions to the power saving mode at a time that is not scheduled in the power saving mode transition schedule, and a sequence for switching the connection of the non-AP MLD 100 and continuing communication is described. The power saving mode is a mode in which only some frames can be received and decoded.

[0107] For example, AP MLD1 transitions to power saving mode when the link quality with all STAs present under its control deteriorates. The control unit 130 of AP MLD1 controls the communication unit 110 to transmit information regarding the connection with the STAs to AP MLD2, which is the target AP. At this time, the control unit 130 of AP MLD1 may transmit to all STAs present under its control a roaming announce frame indicating that the device will transition to power saving mode and change connection to the target AP, with an MCS (Modulation and Coding Scheme) index of 0. The roaming announce frame may be, for example, a frame in which information in the Power management Info field shown in FIG. 9 is described. Furthermore, the roaming announce frame may be transmitted not at the time of transition to power saving mode, but after it has been determined to transition to power saving mode.

[0108] Although not shown in Figure 13, the control unit 130 of AP MLD1 may transfer the static context, which is information regarding the connection with the STA, to AP2-1, for example, when transmitting a Beacon frame or establishing a connection with the STA.

[0109] When transitioning to power saving mode, the control unit 130 of AP MLD1 transfers the dynamic context, which is part of the information related to the connection with the STA, to AP2-1. At this time, the control unit 130 of AP MLD1 may transfer to AP2-1 the data addressed to the non-AP MLD 100 that remains in the buffer of AP MLD1, or part of the data. The transmission timing of the static context and dynamic context is an example. For example, the static context may be transmitted together with the dynamic context, or this information may be transmitted at other times.

[0110] When the control unit 130 of AP MLD2 has completed receiving information regarding the connection with the STA from AP MLD1 and has completed changing the DS mapping, it transmits a roaming response frame from AP2-1 to STA1-1 notifying that the connection switching has been completed. Alternatively, the control unit 130 of AP MLD2 may omit the operation of transmitting the roaming response frame and instead transmit a data frame from AP2-1 to STA1-1. The roaming response frame may also include information indicating that transmission of frames to or reception of frames from the target AP will continue.

[0111] According to this embodiment, even if the source AP suddenly switches to power saving mode, it can send a roaming announce frame to its subordinate STAs and notify them of the target AP, thereby appropriately switching the connection and allowing communication to continue.

[0112] Fourth Embodiment FIG. 14 is a sequence diagram illustrating a connection switching operation in a fourth embodiment.

[0113] In this embodiment, the overall configuration of the communication devices in the wireless communication system and the block diagram of each communication device are the same as those in the first embodiment, and therefore will not be described again. Also, in this sequence diagram, as in the above, AP MLD1 will be used as the source AP that is the source of connection switching, and AP MLD2 will be used as the target AP that is the destination of connection switching. Also, the STA to which connection switching is performed will be described as a non-AP MLD 100.

[0114] In this sequence diagram, it is assumed that the source AP and the target AP have each acquired communication environment information.

[0115] In this embodiment, a description will be given of a sequence for performing connection switching when the non-AP MLD 100 forms an SCS Stream with the AP MLD 1. For example, this connection switching is performed when the AP MLD 1 determines that the QoS requirements of the non-AP MLD 100 cannot be met.

[0116] The control unit 230 of the non-AP MLD 100 transmits an SCS request frame to form an SCS stream between STA1-1 and AP1-1. After receiving this frame, the control unit 130 of the AP MLD 1, for example, references the QoS characteristic element information described in the SCS request frame to determine whether the QoS request of the STA can be satisfied. If the QoS request of the STA cannot be satisfied, the control unit 130 of the AP MLD 1 transmits an SCS response frame stating that an SCS stream cannot be formed and information about the target AP, in order to switch the connection to another AP that can satisfy the QoS request as the target AP.

[0117] After this timing, the control unit 130 of AP MLD1 may transfer the static context, which is part of the information relating to the connection with the STA, to AP2-1, for example, when transmitting a Beacon frame or when establishing a connection with the STA.

[0118] Furthermore, from this timing onwards, the control unit 130 of AP MLD1 transfers the dynamic context, which is part of the information relating to the connection with the STA, to AP2-1. At this time, the control unit 130 of AP MLD1 may transfer to AP2-1 the data addressed to the non-AP MLD 100 that remains in the buffer of AP MLD1, or part of it. Furthermore, the transmission timing of the static context and dynamic context is an example. For example, the static context may be transmitted together with the dynamic context, or this information may be transmitted at other timings.

[0119] Furthermore, the control unit 130 of the AP MLD1 may transmit information regarding the connection with the STA to the AP2-1 using, for example, a Beacon frame or backhaul, without distinguishing between static context and dynamic context.

[0120] When the control unit 10 of AP MLD2 has completed receiving information about the connection with the STA from AP MLD1, it transmits a roaming response frame from AP2-1 to STA1-1 notifying that connection switching has been completed. The roaming response frame may be transmitted from the AP MLD1 side, which is the source AP, or may be transmitted simultaneously with the SCS response frame if the transfer of information about the connection with the STA has already been completed at the time of transmitting the SCS response frame.

[0121] In addition, the roaming response frame may include information regarding SCS stream formation with the target AP.

[0122] According to this embodiment, even if the source AP determines that it cannot satisfy the QoS requirements of the non-AP MLD 100 when it receives an SCS request frame from the non-AP MLD 100, it can select an AP that can satisfy the QoS requirements as the target AP and perform connection switching, thereby forming an SCS stream and continuing communication.

[0123] FIG. 15 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.

[0124] 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 .

[0125] 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. Also connected to the input / output interface 805 are 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.

[0126] 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 memory unit 808 into the RAM 803 via the input / output interface 805 and the bus 804 and executing it.

[0127] 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.

[0128] 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.

[0129] <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.

[0130] 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.

[0131] <Configuration Example of Smartphone> FIG. 16 is a block diagram showing a schematic configuration example of a smartphone to which the present technology is applied.

[0132] 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.

[0133] 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.

[0134] The memory 902 includes RAM and ROM, and stores programs and data executed by the processor 901 .

[0135] The storage 903 includes a storage medium such as a semiconductor memory or a hard disk.

[0136] 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 .

[0137] 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.

[0138] The sensor 907 includes a group of sensors such as a positioning sensor, a gyro sensor, a geomagnetic sensor, and an acceleration sensor.

[0139] The microphone 908 converts the sound input to the smartphone 900 into an audio signal.

[0140] 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.

[0141] 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 link or the second link and the user's operation of the input device 909.

[0142] The wireless communication interface 913 supports one or more wireless LAN standards such as IEEE802.11a, 11b, 11g, 11ac, 11ad, 11ax, 11ay, 11be, and 11bn, and performs wireless communication.

[0143] 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.

[0144] 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.

[0145] 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.

[0146] 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.

[0147] 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 .

[0148] 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, they may communicate via a first link and a second link, respectively.

[0149] 16 , 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.

[0150] 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.

[0151] 16 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.

[0152] 16 , for example, the communication control unit 211 and the control unit 230 in FIG. 4 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.

[0153] The smartphone 900 may operate as a wireless AP (software AP) by the processor 901 executing an AP function at the application level. The wireless communication interface 913 may also have a wireless AP function.

[0154] 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.

[0155] 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.

[0156] <Configuration Example of In-Vehicle Device> FIG. 17 is a block diagram showing an example of a schematic configuration of an in-vehicle device 920 to which the present technology is applied.

[0157] 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.

[0158] 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.

[0159] The memory 922 includes RAM and ROM, and stores programs and data executed by the processor 921 .

[0160] 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.

[0161] The sensor 925 includes a group of sensors such as a gyro sensor, a geomagnetic sensor, and an air pressure sensor.

[0162] 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.

[0163] 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.

[0164] 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.

[0165] 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 of the display device 930 based on information received via the first link or the second link and the user's operation of the input device 929.

[0166] The speaker 931 outputs the audio of the navigation function or the content being played.

[0167] 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.

[0168] 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, and 11bn, and performs wireless communication. The wireless communication interface 933 communicates with other devices via a wireless LAN AP in infrastructure mode. The wireless communication interface 933 also communicates directly with other devices in ad hoc mode or a direct communication mode such as Wi-Fi Direct.

[0169] 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, a proximity wireless communication system, or a cellular communication system.

[0170] The antenna switch 934 switches the connection destination of the antenna 935 among multiple circuits included in the wireless communication interface 933 .

[0171] 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 antenna.

[0172] 17, 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.

[0173] In the in-vehicle device 920 shown in FIG. 17 , the battery 938 is connected via a power supply line partially indicated by a dashed line in the figure, and 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.

[0174] The wireless communication interface 933 may also operate as the communication device described above and provide wireless connection to a terminal carried by a user in the vehicle.

[0175] Moreover, 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 rotation speed, or failure information, and outputs the generated data to the in-vehicle network 941.

[0176] <Configuration Example of Wireless AP> FIG. 18 is a block diagram showing an example of a schematic configuration of a wireless AP 950 to which the present technology is applied.

[0177] 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 .

[0178] 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).

[0179] 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).

[0180] The input device 954 includes, for example, buttons and switches, and receives operations from the user.

[0181] 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 link or the second link and a user's operation of the input device 954. The processor may also be implemented within the controller 951.

[0182] 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 wired communication network 958 may be a LAN such as Ethernet (registered trademark) or a WAN (Wide Area Network).

[0183] The wireless communication interface 963 supports one or more wireless LAN standards such as IEEE802.11a, 11b, 11g, 11n, 11ac, 11ad, 11ax, 11ay, 11be, and 11bn, and provides wireless connection to nearby terminals as an AP.

[0184] The wireless communication interface 963 typically includes a baseband processor, an RF circuit, a power amplifier, and the like.

[0185] 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.

[0186] 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.

[0187] 18, 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 a part of these functions may be implemented in the controller 951.

[0188] 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.

[0189] 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 that program.

[0190] 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.

[0191] 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.

[0192] Furthermore, the effects described in this specification are merely examples and are not limiting, and other effects may also be present.

[0193] 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.

[0194] 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.

[0195] 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.

[0196] 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.

[0197] The present embodiment may also have the following configuration. [Notes] [Item 1] A wireless communication control device comprising: a wireless communication unit included in a first communication device, the wireless communication unit controlling the wireless communication unit performing wireless communication with a second communication device in an autonomous and distributed wireless communication system via one or more access channels, wherein the control unit determines whether to initiate connection switching processing for switching the connection destination of the second communication device from the first communication device to a third communication device, the connection switching processing including processing for transmitting at least one of information related to security and information related to a status of data transmission between the first communication device and the second communication device to the third communication device. [Item 2] The wireless communication control device according to Item 1, wherein the control unit determines whether to perform connection switching processing for switching the connection destination of the second communication device from the first communication device to a third communication device based on a communication schedule of the first communication device or a communication status between the first communication device and the second communication device. [Item 3] The wireless communication control device according to Items 1 and 2, wherein the communication schedule is information on a schedule for transitioning to a power saving mode in the first communication device. [Item 4] The wireless communication control device according to items 1 to 3, wherein the control unit determines to perform connection switching processing for the second communication device when the first communication device is scheduled to transition to a power saving mode. [Item 5] The wireless communication control device according to items 1 to 3, wherein, when determining to perform connection switching processing for the second communication device, the control unit performs processing to notify the second communication device of at least one of an operating state of the first communication device, a delay time required to return from the power saving mode, a transition time to the power saving mode, a duration of the power saving mode, and information indicating a communication device to be a connection switching destination. [Item 6] The wireless communication control device according to items 1 to 5, wherein the security-related information includes at least one of a GTK (Group Temporal Key) and a PTK (Pairwise Transient Key).[Item 7] The wireless communication control device according to items 1 to 6, wherein the information regarding the status of data transmission includes at least one of an SN (sequence number) and a PN (packet number), and wherein the control unit performs processing to transmit at least one of the latest SN and the latest PN to the third communication device when the first communication device transitions to a power saving mode. [Item 8] The wireless communication control device according to items 1 to 6, wherein the control unit further determines to perform connection switching processing for the second communication device when the first communication device receives a connection destination switching request from the second communication device. [Item 9] The wireless communication control device according to item 8, wherein the control unit performs control to selectively use a first operation mode, in which it determines whether to perform connection switching processing for the second communication device based on a communication schedule of the first communication device or a communication status between the first communication device and the second communication device, and a second operation mode, in which it determines to perform connection switching processing for the second communication device when the first communication device receives a connection destination switching request from the second communication device, depending on whether the first communication device is in an on state or an off state. [Item 10] The wireless communication control device according to item 9, wherein the control unit performs control to notify the second communication device or the third communication device of the state of the first operation mode and the second operation mode. [Item 11] The wireless communication control device according to items 2 to 10, wherein the communication status is information related to communication quality of a link between the first communication device and the second communication device. [Item 12] The wireless communication control device according to item 11, wherein the information related to communication quality is QoS characteristic element information or an R-TWT membership setup request. [Item 13] The wireless communication control device according to items 1 to 7, wherein, if a communication device to be a connection destination cannot be found, the control unit cancels transition of the first communication device to a power saving mode and determines not to change the connection destination of the second communication device. [Item 14] The wireless communication control device according to item 11, wherein, if a communication device to be a connection destination that satisfies a communication quality request by the second communication device cannot be found, the control unit determines not to switch the connection of the second communication device.[Item 15] A wireless communication control device included in a third communication device that performs autonomous distributed control, the wireless communication control device comprising: a control unit that controls a wireless communication unit that performs wireless communication with a second communication device that is a target of connection switching over one or more access channels; wherein the control unit determines to switch the connection of the second communication device from the first communication device to the third communication device when the radio wave intensity value of the third communication device is greater than that of a first communication device that is a source of connection switching, or when the number of communication devices connected to the third communication device is fewer than the number of communication devices connected to the first communication device. [Item 16] A wireless communication control device comprising: a control unit that controls a wireless communication unit included in a third communication device, the wireless communication unit performing wireless communication with a second communication device in an autonomous and distributed wireless communication system over one or more access channels, wherein the control unit determines to start connection switching processing for the second communication device from the first communication device to the third communication device based on at least one of a result of comparing a radio wave intensity value of the third communication device with a radio wave intensity value of a first communication device that is a connection switching source, a result of comparing the number of communication devices connected to the first communication device with the number of communication devices connected to the third communication device, a result of comparing a communication quality of a link between the first communication device and the second communication device with the communication quality of a link between the first communication device and the third communication device, and a result of comparing a communication schedule of the first communication device with the communication schedule of the third communication device. [Item 17] The wireless communication control device according to Items 3 to 7, wherein the control unit, when transitioning to the power saving mode during a period not scheduled in the transition schedule to the power saving mode of the first communication device, notifies the second communication device of a communication device to be a connection switching destination after determining to transition to the power saving mode. [Item 18] The wireless communication control device according to Item 17, wherein, after determining to transition to the power saving mode, the control unit controls to transmit information regarding the status of the data transmission to the third communication device. [Item 19] The wireless communication control device according to Items 1 to 18, wherein, when the control unit determines that the communication quality request received from the second communication device cannot be satisfied, the control unit notifies the second communication device of a communication device that satisfies the communication quality request and is to be a connection switching destination.[Item 20] The wireless communication control device according to item 19, wherein the communication quality request is described in an SCS request frame. [Item 21] The wireless communication control device according to item 1, 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 a display on the display device based on information received via the one or more access channels and the operation. [Item 22] The wireless communication control 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 wireless communication control 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 wireless communication control device according to Item 21, wherein the display device is an LED lamp that displays the operation status of the communication device. [Item 25] A vehicle including a wireless communication unit included in a first communication device, the wireless communication unit controlling the wireless communication unit that performs wireless communication with a second communication device in an autonomous decentralized wireless communication system via one or more access channels, wherein the control unit determines whether to start a connection switching process for switching the connection destination of the second communication device from the first communication device to a third communication device, and the connection switching process includes a process of transmitting at least one of information regarding security and information regarding a status of data transmission between the first communication device and the second communication device to the third communication device. [Item 26] The wireless communication control device according to Item 20, wherein, after determining that the communication quality request received from the second communication device cannot be satisfied, the control unit controls transmission of information regarding the connection with the second communication device to the third communication device.[Item 27] ​​A wireless communication control device comprising: a control unit that controls a wireless communication unit included in a second communication device, the wireless communication unit performing wireless communication in an autonomous distributed wireless communication system with a third communication device that is a connection switching destination, over one or more access channels; and when the third communication device requests information regarding the status of data transmission between a first communication device that is a connection switching source and the second communication device, the control unit controls transmission of the information regarding the status of the data transmission to the third communication device. [Item 28] An autonomous distributed control type wireless communication system including a first communication device, a second communication device, and a third communication device, wherein the wireless communication system comprises: a first control unit, a first wireless communication unit included in the first communication device, that controls the first wireless communication unit that performs wireless communication in the wireless communication system with the second communication device over one or more access channels; the first control unit determines whether to start a connection switching process to switch the connection destination of the second communication device from the first communication device to a third communication device; the connection switching process includes a process of transmitting at least one of information related to security and information related to a status of data transmission between the first communication device and the second communication device to the third communication device; and a third control unit, a third wireless communication unit included in the third communication device, that controls the third wireless communication unit that performs wireless communication in the wireless communication system with the second communication device over one or more access channels; and the third control unit includes a process of receiving at least one of the information related to security and the information related to the status of data transmission from the first communication device. [Item 29] The wireless communication system according to Item 28, wherein the first wireless communication unit is included in the first communication device, and the third wireless communication unit is included in the third communication unit.[Item 30] A wireless communication control method including a control method for controlling a wireless communication unit included in a first communication device, the wireless communication unit performing wireless communication with a second communication device in an autonomous distributed wireless communication system via one or more access channels, wherein the control includes control for determining whether to start a connection switching process for switching the connection destination of the second communication device from the first communication device to a third communication device, and the connection switching process includes a process for transmitting at least one of information related to security and information related to the status of data transmission between the first communication device and the second communication device to the third communication device. [Item 31] A communication control program that causes a computer to execute a wireless communication control method, the communication control method including a control method for controlling a wireless communication unit included in a first communication device that performs wireless communication with a second communication device in an autonomous distributed wireless communication system via one or more access channels, the control including control for determining whether to start a connection switching process for switching the connection destination of the second communication device from the first communication device to a third communication device, the connection switching process including a process for transmitting at least one of information related to security and information related to the status of data transmission between the first communication device and the second communication device to the third communication device. [Item 32] A non-transitory portable medium having recorded thereon a communication control program that causes a computer to execute a wireless communication control method, the non-transitory portable medium including a wireless communication unit included in a first communication device, the wireless communication unit performing wireless communication with a second communication device in an autonomous distributed wireless communication system via one or more access channels, the control including control of determining whether to start a connection switching process that switches the connection destination of the second communication device from the first communication device to a third communication device, the connection switching process including a process of transmitting at least one of information related to security and information related to the status of data transmission between the first communication device and the second communication device to the third communication device.

[0198] 1, 2 AP MLD 3 roaming 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 Radio interface unit 124 Amplification unit 130 Control unit 140 Storage unit 150 Antenna 160 Backhaul communication 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 Radio 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 wireless communication control device comprising: a wireless communication unit included in a first communication device, the wireless communication unit having a control unit that controls the wireless communication unit that performs wireless communication with a second communication device in an autonomous and distributed wireless communication system using one or more access channels; the control unit determining whether to initiate a connection switching process to switch the connection destination of the second communication device from the first communication device to a third communication device; and the connection switching process including a process of transmitting at least one of information regarding security and information regarding the status of data transmission between the first communication device and the second communication device to the third communication device.

2. The wireless communication control device according to claim 1, wherein the control unit determines whether to perform a connection switching process to switch the connection destination of the second communication device from the first communication device to a third communication device based on the communication schedule of the first communication device or the communication status between the first communication device and the second communication device.

3. The wireless communication control device according to claim 2, wherein the communication schedule is information on a schedule for transitioning to a power saving mode in the first communication device.

4. The wireless communication control device according to claim 3, wherein the control unit determines to perform connection switching processing for the second communication device when the first communication device is scheduled to transition to a power saving mode.

5. The wireless communication control device according to claim 3, wherein when the control unit determines to perform connection switching processing for the second communication device, the control unit notifies the second communication device of at least one of the following information: the operating state of the first communication device, the delay time required to return from the power saving mode, the transition time to the power saving mode, the duration of the power saving mode, and the communication device to which the connection will be switched.

6. The wireless communication control device according to claim 1, wherein the security-related information includes at least one of a GTK (Group Temporal Key) and a PTK (Pairwise Transient Key).

7. The wireless communication control device according to claim 1, wherein the information relating to the status of data transmission includes at least one of an SN (sequence number) and a PN (packet number), and the control unit performs processing to transmit at least one of the latest SN and PN to the third communication device when the first communication device transitions to a power saving mode.

8. The wireless communication control device according to claim 1, wherein the control unit further determines to perform connection switching processing for the second communication device when the first communication device receives a request to switch connection destination from the second communication device.

9. The wireless communication control device according to claim 8, wherein the control unit performs processing to selectively use a first operation mode in which it determines whether to perform connection switching processing of the second communication device based on the communication schedule of the first communication device or the communication status between the first communication device and the second communication device, and a second operation mode in which it determines to perform connection switching processing of the second communication device when the first communication device receives a request to switch the connection destination from the second communication device, depending on whether the mode is on or off.

10. The wireless communication control device according to claim 9, wherein the control unit performs processing to notify the second communication device or the third communication device of the state of the first operation mode and the second operation mode.

11. The wireless communication control device according to claim 2, wherein the communication status is information relating to the communication quality of the link formed between the first communication device and the second communication device.

12. The radio communication control device according to claim 11, wherein the information relating to communication quality is QoS characteristic element information or an R-TWT membership setup request.

13. The wireless communication control device according to claim 3, wherein the control unit, if unable to find a communication device to connect to, cancels the transition of the first communication device to a power saving mode and determines not to change the connection destination of the second communication device.

14. The wireless communication control device according to claim 11, wherein the control unit determines not to perform connection switching processing for the second communication device if it cannot find a communication device to which the second communication device can be connected that satisfies the communication quality requirements of the second communication device.

15. A wireless communication control device comprising a control unit that controls a wireless communication unit included in a third communication device, the control unit controlling the wireless communication unit that performs wireless communication with a second communication device in an autonomous and distributed wireless communication system over one or more access channels, wherein the control unit determines to start connection switching processing of the second communication device from the first communication device to the third communication device based on at least one of the results of comparing the radio wave strength value of the third communication device with the radio wave strength value of a first communication device that is the source of connection switching, the results of comparing the number of communication devices connected to the first communication device with the number of communication devices connected to the third communication device, the results of comparing the communication quality of the link between the first communication device and the second communication device with the communication quality of the link between the first communication device and the third communication device, and the results of comparing the communication schedule of the first communication device with the communication schedule of the third communication device.

16. A wireless communication control device comprising a control unit, the wireless communication unit being included in a third communication device, that controls the wireless communication unit that performs wireless communication with a second communication device in an autonomous distributed wireless communication system using one or more access channels, wherein the control unit: controls to receive from the first communication device information regarding the status of data transmission between the second communication device and a first communication device that is the source of connection switching for the second communication device; and controls to request from the second communication device information regarding the status of the data transmission that has not been received.

17. The wireless communication control device according to claim 3, wherein, when the first communication device transitions to the power saving mode during a period not scheduled in the transition schedule to the power saving mode, the control unit notifies the second communication device of the communication device to which the connection will be switched after deciding to transition to the power saving mode.

18. The wireless communication control device according to claim 17, wherein the control unit, after deciding to transition to the power saving mode, controls to transmit information regarding the status of the data transmission to the third communication device.

19. The wireless communication control device according to claim 2, wherein, when the control unit determines that the communication quality request received from the second communication device cannot be satisfied, it notifies the second communication device of a communication device that satisfies the communication quality request and is to be the connection switching destination.

20. The radio communication control device according to claim 19, wherein the communication quality request is described in an SCS request frame.

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