Communication device, terminal device, communication system, and communication control method

Abstract

To provide a communication device, a terminal device, a communication system, and a communication control method, etc., which appropriately perform settings in a first communication method even when a terminal device performs handover from a first communication mode to a second communication mode.SOLUTION: A communication device includes a first communication unit that performs communication using a first communication mode, a second communication unit that performs communication using a second communication mode, and a control unit. When a state in which a terminal device and a second communication device communicate with each other using the first communication mode is defined as a first state, and a state in which the first communication unit communicates with the second communication device and the second communication unit communicates with the terminal device is defined as a second state, in a case in which a handover is performed between the first state and the second state, the control unit performs control of communication using the first communication mode by setting corresponding to before the handover even after the handover on the basis of connection setting information representing setting in the communication using the first communication mode before the handover.SELECTED DRAWING: Figure 4

Description

Technical Field

[0001] The present invention relates to a communication device, a terminal device, a communication system, a communication control method, and the like.

Background Art

[0002] Conventionally, a method for performing handover in a communication system is known. For example, Patent Document 1 discloses a method for automatically setting a configuration when performing seamless handover between different communication systems.

[0003] Also, in 3GPP (3rd Generation Partnership Project), the system architecture of 5GS (5G System), which is a fifth-generation (5G) mobile communication system, has been studied, and discussions have been held on the support for new procedures and new functions. 5GS is disclosed in, for example, Non-Patent Document 1.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Non-Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] The method described in Patent Document 1 is a method for automatically configuring information (WEP key, security policy, application information, etc.) in a wireless LAN when performing a handover from a cellular communication network to a wireless LAN. Therefore, Patent Document 1 does not assume that a terminal device will continuously use the first communication method before and after the handover between the first and second communication methods, nor does it assume that the settings in the first communication method will be maintained.

[0006] According to some aspects of this disclosure, it is possible to provide a communication device, terminal device, communication system, and communication control method, etc., that appropriately configure settings in the first communication method even when a terminal device performs a handover between the first communication method and the second communication method. [Means for solving the problem]

[0007] One aspect of the present disclosure relates to a communication device that includes a first communication unit that performs communication using a first communication method, a second communication unit that performs communication using a second communication method different from the first communication method, and a control unit that controls the first communication unit and the second communication unit, wherein the state in which a terminal device and a second communication device are communicating using the first communication method is defined as the first state, and the state in which the communication between the terminal device and the second communication device is relayed by the first communication unit communicating with the second communication device using the first communication method and the second communication unit communicating with the terminal device is defined as the second state, and the control unit, when a handover occurs between the first state and the second state, executes control to perform communication using the first communication method after the handover with the settings corresponding to the settings before the handover, based on connection setting information representing the settings in the communication using the first communication method before the handover.

[0008] A further aspect of this disclosure relates to a terminal device that includes a first terminal communication unit that performs communication using a first communication method, a second terminal communication unit that performs communication using a second communication method different from the first communication method, and a terminal control unit that controls the first terminal communication unit and the second terminal communication unit, wherein the first state is when the second terminal communication unit and the communication device are not communicating, and the first terminal communication unit and the second communication device are communicating, and the second state is when the second terminal communication unit communicates with the communication device, and the communication device and the second communication device perform communication using the first communication method, thereby the communication device relaying communication with the second communication device, and the terminal control unit, when a handover occurs between the first state and the second state, executes control to perform communication using the first communication method after the handover with the settings corresponding to the settings before the handover, based on connection setting information representing the settings in the communication using the first communication method before the handover.

[0009] A further aspect of this disclosure relates to a communication system that includes a terminal device and a communication device, wherein a first state is defined as a state in which the communication device and the terminal device are not communicating and the terminal device and a second communication device are communicating using a first communication method, and a second state is defined as a state in which the communication device relays communication between the terminal device and the second communication device by the communication device communicating with the second communication device using the first communication method and the communication device communicating with the terminal device using the second communication method, and when a handover occurs between the first state and the second state, the communication device executes control to continue communicating using the first communication method after the handover with the settings corresponding to the settings before the handover, based on connection setting information representing the settings in the communication using the first communication method before the handover.

[0010] A further aspect of this disclosure relates to a communication control method in which, when a handover occurs between the first and second states, the communication device performs control to continue communication using the first communication method after the handover, based on connection setting information representing the settings in the communication using the first communication method before the handover. The first state is defined as a state in which the communication device and the terminal device are not communicating, and the terminal device and the second communication device are communicating using the first communication method, and the second state is defined as a state in which the communication device relays communication between the terminal device and the second communication device by communicating with the second communication method, and a handover occurs between the first and second states. [Brief explanation of the drawing]

[0011] [Figure 1A] A diagram illustrating the first state. [Figure 1B] A diagram illustrating the second state. [Figure 2] Example of terminal device configuration. [Figure 3] Example of a communication device configuration. [Figure 4] A schematic diagram illustrating the process of the first embodiment. [Figure 5] A diagram illustrating the processing flow of the first embodiment. [Figure 6] A flowchart illustrating the processing of the second communication device. [Figure 7] A flowchart illustrating the processing of a communication device. [Figure 8] A flowchart explaining the processing performed by the terminal device. [Figure 9] A schematic diagram illustrating the process of the second embodiment. [Figure 10] A diagram illustrating the processing flow of the second embodiment. [Figure 11] A flowchart illustrating the processing of a communication device. [Figure 12] A flowchart explaining the processing performed by the terminal device. [Modes for carrying out the invention]

[0012] Hereinafter, this embodiment will be described while referring to the drawings. For the drawings, the same or equivalent elements are denoted by the same reference numerals, and redundant descriptions are omitted. Note that the embodiment described below does not unduly limit the content described in the claims. Also, not all of the configurations described in this embodiment are essential constituent elements of the present disclosure.

[0013] 1. System configuration example FIG. 1A and FIG. 1B are diagrams illustrating the configuration of a communication system 10 according to this embodiment. The communication system 10 includes a terminal device 100 and a communication device 200. The communication system 10 may also include a second communication device 300 and a core network 400.

[0014] [[ID=​​​​The second communication device 300 may be a 5G NR base station (gNB). A1 in FIGS. 1A and 1B represents a cell within the range that can communicate with the second communication device 300. Hereinafter, for the main purpose of explaining the example of 5G, A1 is denoted as a 5G cell. A device corresponding to 5GS and located within the range of the 5G cell A1 can perform 5G communication with the second communication device 300.

[0016] The communication device 200 is connected to the core network 400 via the second communication device 300 which is an NR base station. The core network 400 is, for example, a 5G core network. Hereinafter, the 5G core network is also denoted as 5GC.

[0017] Also, the communication device 200 communicates using a second communication method different from the first communication method. The second communication method is, for example, wireless communication according to the communication method defined in IEEE (Institute of Electrical and Electronics Engineers) 802.11. Specifically, the second communication method may be communication using Wi-Fi (registered trademark). Hereinafter, communication using Wi-Fi is denoted as Wi-Fi communication. In the following, Wi-Fi communication will be described as a specific example of communication using the second communication method in this embodiment, but the second communication method is not limited to Wi-Fi. For example, various non-3GPP communication methods can be used as the second communication method. That is, "Wi-Fi communication" in the following description can be replaced with the second communication method, and the second communication method may use a method other than Wi-Fi.

[0018] The communication device 200 may be a device that functions as an AP (access point) in Wi-Fi. A2 in FIGS. 1A and 1B represents a cell within the range that can communicate with the communication device 200 using the second communication method. Hereinafter, for the main purpose of explaining the example of Wi-Fi, A2 is denoted as a Wi-Fi cell. For example, a device that functions as a STA (station) in Wi-Fi and is located within the range of the Wi-Fi cell A2 can communicate with the communication device 200.

[0019] In this embodiment, the terminal device 100 is a device capable of performing communication using a first communication method and communication using a second communication method, and switches the connected device depending on the state. For example, as shown in Figure 1A, if the terminal device 100 is within the range of 5G cell A1 and capable of performing 5G communication with sufficient communication quality, the terminal device 100 directly performs 5G communication with the second communication device 300. The terminal device 100 is a device that functions as a UE (User Equipment) in 5G, and in a narrow sense, it may be a UE capable of SA (Stand Alone) communication.

[0020] On the other hand, if the terminal device 100 is located outside the range of 5G cell A1 and within the range of Wi-Fi cell A2, and the communication quality of Wi-Fi communication is determined to be relatively high, the terminal device 100 will communicate with the communication device 200 via Wi-Fi, as shown in Figure 1B. In this case, the terminal device 100 will function as a STA (Statistical Agent) in Wi-Fi.

[0021] As shown in Figure 1B, the communication device 200 may be a device capable of performing both LAN (Local Area Network) communication and WAN (Wide Area Network) communication. The communication device 200 is connected to the terminal device 100 on the LAN side and to the core network 400 via the second communication device 300 on the WAN side. This enables the terminal device 100 to communicate with the second communication device 300, which is an NR base station, and the core network 400, which is a 5GC, via the communication device 200.

[0022] Hereinafter, as shown in Figure 1A, the state in which terminal device 100 and communication device 200 are not communicating, and terminal device 100 and second communication device 300 are communicating via 5G, will be referred to as the first state. Furthermore, as shown in Figure 1B, the state in which communication device 200 is communicating via 5G with second communication device 300, and communication device 200 is communicating via Wi-Fi with terminal device 100, will be referred to as the second state. In other words, the second state represents a state in which communication device 200 relays communication between terminal device 100 and second communication device 300.

[0023] In this embodiment, the communication device 200 may be, for example, a CPE (Customer Premises Equipment) placed in the user's home or other location. For example, the terminal device 100 performs Wi-Fi communication at the home or other location where the communication device 200 is placed, and performs 5G communication when away from the communication device 200 or at other locations. However, the communication device 200 may also be a device placed in a commercial facility or the like, and various variations are possible regarding the specific placement location.

[0024] In 5GS, it is possible to maximize 5G performance by using appropriate network slices or priority control. For example, devices performing 5G communication can utilize functions such as high-capacity communication, ultra-low latency communication, and ultra-high-connection communication provided by 5GS. For example, in the first state, 5G performance can be utilized in communication between terminal device 100 and second communication device 300 by selecting an appropriate network slice. Similarly, in the second state, 5G performance can be utilized in communication between communication device 200 and second communication device 300 by selecting an appropriate network slice. However, in order to do this, it is necessary to appropriately acquire information that identifies the connection settings (hereinafter referred to as connection setting information).

[0025] In particular, in this embodiment, it is assumed that a transition between the first state and the second state occurs when the situation changes due to the movement of the terminal device 100, etc. Since the equipment (base station) that the terminal device 100 communicates with is different in the first state and the second state, the transition between states will also be referred to as a handover below. When a handover occurs, even if the 5G performance can be utilized to the fullest extent in the first state, appropriate handover control is necessary to utilize the 5G performance after the transition to the second state. The same applies to handover control from the second state to the first state.

[0026] Therefore, in this embodiment, when a handover occurs between the first state and the second state, a method is proposed in which, based on connection setting information representing the settings for communication using the first communication method before the handover, communication using the first communication method is performed after the handover with the corresponding settings before the handover. In this way, it becomes possible to appropriately carry over the settings of the first communication method during a handover between the first state and the second state. The method of this embodiment will be described in detail below. First, an example of the configuration of the terminal device 100 and the communication device 200 will be described using Figures 2 and 3. Then, the handover control from the first state to the second state will be described in the first embodiment, and the handover control from the second state to the first state will be described in the second embodiment.

[0027] Figure 2 is a block diagram showing the configuration of the terminal device 100. The terminal device 100 includes a terminal control unit 110, a terminal storage unit 120, a first terminal communication unit 130, and a second terminal communication unit 140. However, the configuration of the terminal device 100 is not limited to Figure 2, and modifications such as omitting some components or adding other components are possible. The same applies to other figures such as Figure 3, where modifications such as omitting or adding components are possible.

[0028] The terminal control unit 110 controls each part of the terminal device 100, including the first terminal communication unit 130 and the second terminal communication unit 140. The terminal control unit 110 of this embodiment is composed of the following hardware. The hardware may include at least one of a circuit that processes digital signals and a circuit that processes analog signals. For example, the hardware may consist of one or more circuit devices or one or more circuit elements mounted on a circuit board. One or more circuit devices may be, for example, an IC (Integrated Circuit) or an FPGA (field-programmable gate array). One or more circuit elements may be, for example, a resistor or a capacitor.

[0029] The terminal control unit 110 may also be implemented by the following processor. The terminal device 100 of this embodiment includes a memory for storing information and a processor that operates based on the information stored in the memory. The information is, for example, a program and various types of data. The processor includes hardware. Various types of processors can be used, such as a CPU (Central Processing Unit), a GPU (Graphics Processing Unit), or a DSP (Digital Signal Processor). The memory may be a semiconductor memory such as SRAM (Static Random Access Memory), DRAM (Dynamic Random Access Memory), or flash memory, or it may be a register, or it may be a magnetic storage device such as a hard disk drive (HDD), or it may be an optical storage device such as an optical disk drive. For example, the memory stores instructions that can be read by a computer, and the functions of the terminal control unit 110 are realized as processing when the processor executes these instructions. The instructions here may be instructions from an instruction set that constitutes a program, or they may be instructions that instruct the hardware circuit of the processor to operate.

[0030] The terminal control unit 110 performs handover control from the first state to the second state, and handover control from the second state to the first state. For example, the terminal control unit 110 performs the handover based on information from the communication device 200 or the second communication device 300.

[0031] The terminal storage unit 120 is a work area of ​​the terminal control unit 110 and stores various information. The terminal storage unit 120 can be implemented using various types of memory, and the memory may be semiconductor memory such as SRAM, DRAM, ROM (Read Only Memory), or flash memory, or it may be a register, a magnetic storage device, or an optical storage device.

[0032] The terminal storage unit 120 may store information that associates, for example, an application program executed on the terminal device 100 with connection setting information that represents the communication settings in the application program. Hereinafter, the application program will also be simply referred to as the application. For example, the terminal control unit 110 may be able to change the connection setting information based on the information stored in the terminal storage unit 120 when the running application software changes.

[0033] The first terminal communication unit 130 is an interface for communication over a network and includes, for example, an antenna, an RF (radio frequency) circuit, and a baseband circuit. The first terminal communication unit 130 operates according to the control of the terminal control unit 110. The first terminal communication unit 130 may also include a communication control processor different from the terminal control unit 110. The first terminal communication unit 130 performs communication using a first communication method.

[0034] The first communication method is a communication method used in, for example, 5GS. For example, as shown in Figure 1A, the first terminal communication unit 130 communicates with the core network 400, which is 5GC, via the second communication device 300 in the first state.

[0035] The second terminal communication unit 140 is an interface for communication over a network and includes, for example, an antenna, an RF circuit, and a baseband circuit. The second terminal communication unit 140 operates according to the control of the terminal control unit 110. The second terminal communication unit 140 may also include a communication control processor different from that of the terminal control unit 110.

[0036] The second terminal communication unit 140 performs communication using a second communication method. The second communication method is a different communication method from the first communication method, and is, for example, a Wi-Fi communication method as described above using Figures 1A and 1B. For example, in the second state, the second terminal communication unit 140 performs Wi-Fi communication with the communication device 200.

[0037] Figure 3 is a block diagram showing the configuration of the communication device 200. The communication device 200 includes a control unit 210, a storage unit 220, a first communication unit 230, and a second communication unit 240.

[0038] The control unit 210 controls each part of the terminal device 100, including the first communication unit 230 and the second communication unit 240. The control unit 210 in this embodiment includes hardware that includes at least one of a circuit for processing digital signals and a circuit for processing analog signals. For example, the hardware can consist of one or more circuit devices or one or more circuit elements mounted on a circuit board.

[0039] The control unit 210 can be implemented using various processors such as a CPU, GPU, or DSP. The communication device 200 includes a memory for storing information and the processor that operates based on the information stored in the memory. The memory stores instructions that can be read by the computer, and the functions of the control unit 210 are realized as processing when the processor executes these instructions.

[0040] The control unit 210 performs handover control from the first state to the second state, and handover control from the second state to the first state. For example, the control unit 210 may obtain connection setting information from the second communication device 300. Alternatively, the control unit 210 may determine whether a handover is necessary based on information from the terminal device 100, and perform a process to transmit connection setting information based on the determination result. Details of the process will be described later.

[0041] The storage unit 220 is the work area of ​​the control unit 210 and stores various information. The storage unit 220 can be implemented using various types of memory, which may be semiconductor memory, registers, magnetic memory devices, or optical memory devices.

[0042] The first communication unit 230 is an interface for communication over a network and includes, for example, an antenna, an RF circuit, and a baseband circuit. The first communication unit 230 operates according to the control of the control unit 210. The first communication unit 230 may also include a communication control processor different from the control unit 210. The first communication unit 230 performs communication using a first communication method. For example, the first communication unit 230 communicates with the core network 400, which is 5GC, via the second communication device 300.

[0043] The second communication unit 240 is an interface for communication over a network and includes, for example, an antenna, an RF circuit, and a baseband circuit. The second communication unit 240 operates according to the control of the control unit 210. The second communication unit 240 may also include a communication control processor different from the control unit 210. The second communication unit 240 performs communication using a second communication method. For example, the second communication unit 240 performs Wi-Fi communication with the terminal device 100.

[0044] 2. First Embodiment Figure 4 is a schematic diagram illustrating the handover control in the first embodiment. As shown in Figure 4, the handover control here refers to the control for transitioning from the first state to the second state. The first state is a state in which, from the perspective of the communication device 200, the second communication unit 240 and the terminal device 100 are not communicating via Wi-Fi, and the terminal device 100 and the second communication device 300 are communicating via 5G. The second state is a state in which the communication between the terminal device 100 and the second communication device 300 is relayed by the first communication unit 230 communicating with the second communication device 300 and the second communication unit 240 communicating with the terminal device 100. In this case, a smooth handover is possible by carrying over the settings of the 5G communication CM1 in the first state to the 5G communication CM2 in the second state.

[0045] In the first state before handover, let's assume that communication utilizing 5G performance was taking place, for example, as 5G communication CM1. For example, in 5GS, multiple logical segments with different characteristics can be operated on the same 5GC through virtualization of network functions. The logical resource segment used when separating, managing, and operating network functions is called a network slice (hereinafter also simply referred to as a slice). For example, in 5GC, it is possible to configure it so that some C-plane functions such as NSSF (Network Slice Selection Function), AUSF (Authentication Server Function), and UDM (Unified Data Management) are common to multiple slices, while some C-plane functions such as AMF (Access and Mobility Management Function) and SMF (Session Management Function), as well as UPF (User Plane Function), are provided for each slice. However, various modifications can be made to the specific architecture of network slicing, such as commonizing AFM across multiple slices, or providing multiple AUSF or UDMs. Furthermore, since the functions of each NF (Network Function) are disclosed in Non-Patent Literature 1, etc., a detailed explanation will be omitted.

[0046] In this case, each slice can have different characteristics. For example, the first slice may have characteristics suitable for eMBB (enhanced Mobile Broadband), the second slice may have characteristics suitable for URLLC (Ultra-Reliable and Low Latency Communications), and the third slice may have characteristics suitable for MIoT (Massive Internet of Things). MIoT can also be referred to as mMTC (massive Machine-Type Communications). By sending information to the NSSF for the UE connected to the 5GC to select the appropriate slice, communication with the desired characteristics can be achieved.

[0047] For example, in the first state, terminal device 100 communicates with second communication device 300 using a URLLC-compatible slice as the network slice in 5GS network slicing. For example, terminal device 100 is running application software that requires high reliability and low latency, and may request second communication device 300 to establish communication using a URLLC-compatible slice based on that application software. For example, terminal device 100 sends a request to establish a PDU (Protocol Data Unit) session specifying a URLLC-compatible slice, and when the core network 400 approves the establishment request, communication using a URLLC-compatible slice is established between terminal device 100 and the data network (DN). A PDU session represents a logical connection from the UE to the data network.

[0048] In this way, for example, depending on the application software executed by the terminal device 100, a slice suitable for that application software can be used, making it possible to perform communication that makes maximum use of 5G performance in the first state before handover. Of course, if the characteristics of the application software are different, slices other than URLLC, such as eMBB, MIoT, or other slices, may be used. Furthermore, the method of associating application software with slices is just one example, and there is no prejudice against determining the slice to be used using other methods.

[0049] Figure 5 is a diagram illustrating the processing flow of this embodiment. First, at the start of this process, as shown in step S101, communication in the first state, that is, 5G communication between the terminal device 100 and the second communication device 300, takes place. As described above, the 5G communication here is, for example, communication using slices corresponding to URLLC.

[0050] In step S102, the second communication device 300 transmits a signal to the terminal device 100 instructing it to measure information about the surrounding base station. Here, the base station includes the gNB, which is a base station in the first communication system, and the AP, which is a base station in the second communication system.

[0051] In step S103, the terminal device 100 measures information about the base station and transmits the measurement results to the second communication device 300. For example, the terminal device 100 obtains as measurement results information about the communication quality of 5G communication with gNB including the second communication device 300, and information representing the communication quality of Wi-Fi communication with AP including communication device 200. Hereinafter, the communication quality of 5G communication will be referred to as 5G quality, and the communication quality of Wi-Fi communication will be referred to as Wi-Fi quality.

[0052] 5G quality and Wi-Fi quality are information representing, for example, the received signal strength from the base station in the terminal device 100. For example, each quality may be numerical data such as RSSI (Received Signal Strength Indicator). In addition, in 5G, indices such as RSRP (Reference Signal Received Power) and RSRQ (Reference Signal Received Quality) are known and may be used as 5G quality. Furthermore, 5G quality and Wi-Fi quality are not limited to the RSSI values ​​themselves, but may also be calculated using scores or the like based on these values. In addition, there is no preclude using other information such as the degree of fluctuation of received signal strength or the error detection rate in the calculation of 5G quality and Wi-Fi quality. Moreover, in this embodiment, 5G quality and Wi-Fi quality only need to be information in a form that allows for comparison of their levels, and various variations are possible in the specific data format and calculation method.

[0053] For example, in the first state, the processes in steps S102 and S103 are performed periodically. That is, the second communication device 300 periodically monitors the communication quality of the 5G communication and Wi-Fi communication of the terminal device 100. The terminal device 100 may transmit the 5G quality or Wi-Fi quality values ​​themselves, or it may transmit only whether or not an event occurred. For example, if the terminal device 100 determines that the 5G quality is higher than the Wi-Fi quality, it can maintain the first state and therefore determines that there is no event. On the other hand, if the terminal device 100 determines that the Wi-Fi quality is 5G quality or higher, in step S104, the terminal device 100 transmits an event indicating the occurrence of this event to the second communication device 300.

[0054] If no event occurs, the 5G quality will be higher than the Wi-Fi quality, so there is no problem in maintaining the first state. Therefore, in this case, the processing from step S104 onwards is not executed, and the terminal device 100 and the second communication device 300 continue 5G communication in the first state shown in step S101.

[0055] On the other hand, if an event is notified, it means that the 5G quality is lower than the Wi-Fi quality, so it is highly likely that higher quality communication can be performed by transitioning to the second state. Therefore, in step S105, the second communication device 300 decides to perform a handover. Figure 5 shows an example in which the terminal device 100 compares the 5G quality and Wi-Fi quality and reports the event to the second communication device 300 based on the comparison result. However, information representing the 5G quality and Wi-Fi quality may be transmitted to the second communication device 300, and the second communication device 300 may determine whether or not to perform the process in step S105 by performing a comparison process between these two. In Figure 5, handover is denoted as HO, and this is the same in Figure 6 and subsequent figures.

[0056] If a handover is decided upon, in step S106, the second communication device 300 requests a handover from the communication device 200, which is a Wi-Fi AP. As mentioned above, the communication device 200 is a device capable of 5G communication with the second communication device 300, and this 5G communication can be performed regardless of whether or not it is accepting STA connections as a Wi-Fi AP. More specifically, the communication device 200 may perform 5G communication with the second communication device 300 in the first state. The communication device 200 and the second communication device 300 may send and receive information to identify the devices by using, for example, the 5GS gNB-gNB Xn interface function, or a similar function. In this way, the second communication device 300 can appropriately identify the communication device 200, which is the handover destination (Wi-Fi AP) for the terminal device 100. For example, the second communication device 300 can obtain information from the terminal device 100 to identify a base station with high Wi-Fi quality, and may identify the communication device 200 as the handover destination by comparing this information with information obtained in advance using the Xn interface function. Alternatively, the communication device 300 may register the 5G cell A1 of the second communication device 300 (specifically, the Cell ID, etc.) as a nearby adjacent cell in the communication device 200 in advance, and the Wi-Fi cell A2 of the communication device 200 (specifically, the SSID, etc.) as a nearby adjacent cell in the second communication device 300. Even with such methods, the second communication device 300 can appropriately identify the communication device 200, which is the handover destination for the terminal device 100.

[0057] In step S106, the control unit 210 of the communication device 200 may receive connection setting information from the second communication device 300 via the first communication unit 230. The connection setting information here represents the settings for communication using the first communication method. In this way, it becomes possible to appropriately take over the settings for the first communication method. For example, the settings for 5G communication CM1 shown in Figure 4 can be taken over to 5G communication CM2, i.e., communication between the communication device 200 and the second communication device 300, thereby enabling a smooth handover.

[0058] In the example described above, the terminal device 100 is running application software that requires URLLC, and by handing over the slice corresponding to the URLLC used in 5G communication CM1 to 5G communication CM2, it can utilize 5G performance even after transitioning to the second state. Therefore, the connection setting information in this embodiment may be information that determines the network slice in 5GS network slicing.

[0059] More specifically, the connection configuration information in this embodiment is NSSAI (Network Slice Selection Assistance Information), which is information for determining the slice, and more narrowly, S-NSSAI (Single-NSSAI). S-NSSAI includes SST (Slice / Service Type) and SD (Slice Differentiator). SST is numerical data for determining the slice type; for example, 1 corresponds to eMBB, 2 corresponds to URLLC, and 3 corresponds to MIoT. SD is used when identifying multiple slices within the same SST.

[0060] For example, in step S106, the second communication device 300 instructs the communication device 200 to perform communication using a PDU session that includes a specific S-NSSAI.

[0061] In step S107, the communication device 200 responds to the handover request in step S106. Specifically, the communication device 200 communicates with the second communication device 300 using a PDU session that matches the instructions.

[0062] Based on the processing in steps S106 and S107, in step S108, 5G communication based on connection setting information is established between the communication device 200 and the second communication device 300. In the above example, the communication established in step S108 is 5G communication using slices corresponding to URLLC, similar to the communication in step S101.

[0063] In step S109, the second communication device 300 instructs the terminal device 100 to perform a handover. The information transmitted in step S109 may include, for example, information about the handover destination communication device 200 (e.g., SSID) and a statement instructing the terminal device 100 to perform Wi-Fi communication to the said communication device 200.

[0064] In step S110, the terminal device 100 responds to the handover instruction. The terminal device 100 then establishes Wi-Fi communication with the communication device 200 and disconnects 5G communication with the second communication device 300.

[0065] As a result, as shown in step S111, a state is achieved in which the terminal device 100 and the communication device 200 perform Wi-Fi communication, and the communication device 200 and the second communication device 300 perform 5G communication using the desired slice. This makes it possible to utilize 5G performance in the part beyond the communication device 200 when, for example, the terminal device 100 sends and receives data with the second communication device 300 (and the core network 400 beyond it).

[0066] Furthermore, it is conceivable that the communication device 200 may establish Wi-Fi connections with multiple STAs simultaneously, and that each STA may use a different slice. In other words, the communication device 200 needs to appropriately associate and manage STAs with slices (or PDU sessions). Therefore, the communication device 200 may acquire the identification information of the terminal device 100 via the second communication device 300 at the timing of step S106 or at any timing between steps S108 and S111. The identification information of the terminal device 100 is, for example, a MAC address, but other information may be used. The communication device 200 stores the MAC address and slice in association in the storage unit 220. In the example in Figure 5, for packets where the MAC address of the terminal device 100 is the source or destination, the communication device 200 uses the slice corresponding to URLLC to perform 5G communication with the second communication device 300. In this way, 5G communication between the communication device 200 and the second communication device 300 is controlled in correspondence with the terminal device 100, making it possible for the terminal device 100 to utilize 5G performance.

[0067] The detailed operation of each device in the process shown in Figure 5 will be explained below using the flowcharts in Figures 6-8.

[0068] Figure 6 is a flowchart illustrating the processing of the second communication device 300. First, in step S201, the second communication device 300 monitors the communication quality of the terminal device 100. The communication quality here refers to, for example, the 5G quality and Wi-Fi quality mentioned above. For example, the second communication device 300 requests measurement from the terminal device 100 and obtains the measurement results.

[0069] In step S202, the second communication device 300 determines whether the Wi-Fi quality has become 5G quality or higher. If the 5G quality is higher (No in step S202), the second communication device 300 returns to step S201 and continues processing. In other words, the second communication device 300 continues monitoring while maintaining the first state until the Wi-Fi quality becomes 5G quality or higher.

[0070] If the Wi-Fi quality becomes 5G quality or higher (Yes in step S202), in step S203, the second communication device 300 decides to perform a handover. For example, in step S203, the second communication device 300 identifies the communication device 200 to which the handover will take place, identifies the MAC address of the terminal device 100, and so on.

[0071] In step S204, the second communication device 300 requests a handover from the communication device 200. Specifically, it sends connection configuration information to the communication device 200 that represents the settings for the 5G communication CM1 with the terminal device 100. For example, the second communication device 300 requests the communication device 200 to communicate in a PDU session that includes a specific slice.

[0072] In step S205, the second communication device 300 determines whether a PDU session matching the request in step S204 exists. For example, as will be described later, it is possible that the communication device 200 does not support communication using network slices. Therefore, in step S205, the second communication device 300 determines, based on the capabilities of the communication device 200, whether it is possible to select a PDU session according to the request. As will be described later using Figure 7, the communication device 200 may determine whether it is possible to respond to the request and send a request for a communication connection according to its capabilities. In this case, the second communication device 300 may omit a specific determination regarding the capabilities of the communication device 200 and will process a response to the connection request from the communication device 200.

[0073] If a PDU session matching the request exists (Yes in step S205), in step S206, the second communication device 300 establishes communication with the communication device 200 according to the connection configuration information, for example, 5G communication using a slice corresponding to URLLC. If no PDU session matching the request exists (No in step S205), in step S207, the second communication device 300 establishes 5G communication with the communication device 200 using a default PDU session.

[0074] After processing in step S206 or step S207, in step S208, the second communication device 300 instructs the terminal device 100 to perform a handover. As a result, Wi-Fi communication is established between the terminal device 100 and the communication device 200, and in step S209, communication is established between the terminal device 100 and the second communication device 300 via the communication device 200.

[0075] Figure 7 is a flowchart illustrating the processing of the communication device 200. Here, we describe an example where, in step S301, the first communication unit 230 has already established 5G communication with the second communication device 300 using a default PDU session. For example, the first communication unit 230 may use the default PDU session to send and receive identification information, which is information that identifies each other, and other control information with the second communication device 300. Also, in the state of step S301, a second terminal device different from terminal device 100 may already be connected to the communication device 200 as a Wi-Fi STA. In this case, the first communication unit 230 may perform 5G communication in order to relay communication between the second terminal device and the second communication device 300. In this case, the 5G communication may be communication using a default PDU session, or it may be a PDU session corresponding to the second terminal device.

[0076] In step S302, the control unit 210 determines whether or not it has received a handover request from the second communication device 300. The handover request corresponds to step S106 in Figure 5 and step S204 in Figure 6. If the handover request has not been received (No in step S302), the process in step S302 is executed again.

[0077] If a handover request is received (Yes in step S302), in step S303, the control unit 210 determines whether the communication device 200 corresponds to the connection setting information. For example, if the connection setting information is S-NSSAI, the control unit 210 determines whether it has the function to select a network slice.

[0078] If the communication device 200 does not support the connection setting information (No in step S303), in step S304, the control unit 210 selects a default PDU session and uses the selected PDU session to perform 5G communication between the first communication unit 230 and the second communication device 300.

[0079] If the communication device 200 is compatible with connection setting information (Yes in step S303), in step S305, the control unit 210 obtains the connection setting information from the second communication device 300 via the first communication unit 230. Note that the connection setting information may also be included in the handover request, in which case the processing in step S305 can be omitted.

[0080] In step S306, the control unit 210 determines whether a PDU session corresponding to the connection setting information has already been selected as the PDU session to be used for 5G communication between the first communication unit 230 and the second communication device 300. If it has not been selected (No in step S306), in step S307, the control unit 210 selects a PDU session corresponding to the connection setting information and uses the selected PDU session to communicate between the first communication unit 230 and the second communication device 300. If it has already been selected (Yes in step S306), in step S308, the control unit 210 maintains the existing PDU session. For example, if the communication device 200 has already established a URLLC-compatible PDU session with the second communication device 300 at an earlier stage, and the connection setting information specifies a slice that corresponds to URLLC, the existing PDU session can be used as is.

[0081] As shown in steps S306-S308, the control unit 210 may perform control to select a PDU session based on connection setting information. In this way, it becomes possible to appropriately select the PDU session to be used, for example, to use the session corresponding to the PDU session used in the first state in the second state as well. As a result, it becomes possible to maintain a state that takes advantage of the performance of the first communication method before and after the handover.

[0082] When any of steps S304, S307, or S308 is performed, 5G communication is established between the first communication unit 230 and the second communication device 300. As a result, a Wi-Fi connection is established between the second communication unit 240 and the terminal device 100, and in step S309, the communication connection between each device is established, and the handover to the second state is completed.

[0083] Figure 8 is a flowchart illustrating the processing of the terminal device 100. Here, we will describe an example in which, in step S401, the first terminal communication unit 130 has already established 5G communication with the second communication device 300 using slices corresponding to URLLC.

[0084] In step S402, the terminal control unit 110 uses the first terminal communication unit 130 and the second terminal communication unit 140 to acquire information representing 5G quality and Wi-Fi quality. In step S403, it is determined whether the 5G quality has deteriorated compared to the Wi-Fi quality. If the 5G quality is higher than the Wi-Fi quality (No in step S403), the terminal control unit 110 returns to step S402 and continues monitoring the communication quality.

[0085] If the Wi-Fi quality is determined to be 5G quality or higher (Yes in step S403), in step S404, the terminal control unit 110 reports the occurrence of the event to the second communication device 300 via the first terminal communication unit 130. As a result, the second communication device 300 decides to perform a handover (step S203 in Figure 6).

[0086] In step S405, the terminal control unit 110 receives a handover instruction from the second communication device 300 via the first terminal communication unit 130. The handover instruction corresponds to step S109 in Figure 5 and step S208 in Figure 6. The handover instruction received in step S405 may be an instruction to establish Wi-Fi communication with the communication device 200 and an instruction to disconnect 5G communication with the second communication device 300.

[0087] In step S406, the terminal control unit 110 disconnects the 5G communication with the second communication device 300 via the first terminal communication unit 130. In step S407, the terminal control unit 110 establishes Wi-Fi communication with the communication device 200 via the second terminal communication unit 140. Steps S406 and S407 are not limited to being performed in this order. For example, Wi-Fi communication may be established first, and after it is confirmed that communication with the second communication device 300 via the communication device 200 is possible, the 5G communication may be disconnected.

[0088] As shown in step S305 of Figure 7, the control unit 210 of the communication device 200 acquires information representing the settings for communication between the terminal device 100 and the second communication device 300 using the first communication method as connection setting information in the first state. The control unit 210 then communicates with the terminal device 100 via the second communication unit 240 (step S407 of Figure 8), and also communicates with the second communication device 300 via the first communication unit 230 based on the connection setting information (steps S307, S309), thereby performing handover control from the first state to the second state. In the method of this embodiment, as shown in Figure 4, the terminal device 100 uses the first communication method in the first state and the second communication method in the second state, so the communication method itself changes. However, in the second state assumed in this embodiment, the communication device 200 that relays communication between the terminal device 100 and the second communication device 300 is capable of performing communication using the first communication method. Therefore, by transferring the connection settings between terminal device 100 and second communication device 300 to the connection settings between communication device 200 and second communication device 300, it becomes possible to appropriately utilize the performance of the first communication method even when a handover occurs.

[0089] Furthermore, the method of this embodiment is applicable to terminal devices 100, communication systems 10, communication control methods, etc., which, when a handover occurs between a first state and a second state, execute control to continue communication using the first communication method after the handover using the settings corresponding to the settings before the handover, based on connection setting information representing the settings for communication using the first communication method before the handover.

[0090] For example, the method of this embodiment can be applied to a terminal device 100 including a terminal control unit 110, a first terminal communication unit 130, and a second terminal communication unit 140, as shown in Figure 2. When a communication device 200 communicates with the second communication device 300 using settings corresponding to the settings in the first communication between the first terminal communication unit 130 and the second communication device 300 using the first communication method in the first state, the terminal control unit 110 of the terminal device 100 may perform a handover from the first state to the second state by establishing communication between the second terminal communication unit 140 and the communication device 200. In this way, even when a terminal device 100 capable of performing communication using both the first and second communication methods transitions to a state where it performs communication using the second communication method, it becomes possible to appropriately utilize the performance of the first communication method.

[0091] Furthermore, the method of this embodiment can be applied to a communication system 10 including the terminal device 100 and the communication device 200. In the first state, the communication device 200 of the communication system 10 acquires information representing the settings for communication between the terminal device 100 and the second communication device 300 using the first communication method as connection setting information. Furthermore, the communication device 200 communicates with the terminal device 100 using the second communication method, and also communicates with the second communication device 300 using the first communication method based on the connection setting information, thereby performing handover control from the first state to the second state.

[0092] Furthermore, the method of this embodiment can be applied to a communication control method. The communication control method includes the steps of: acquiring information representing the settings for communication between the terminal device 100 and the second communication device 300 using a first communication method as connection setting information in the first state; and performing handover control from the first state to the second state by causing the terminal device 100 and the communication device 200 to communicate using the second communication method, and causing the communication device 200 and the second communication device 300 to communicate using the first communication method based on the connection setting information.

[0093] Furthermore, some or all of the processing performed by the terminal device 100 or the communication device 200 in this embodiment may be implemented by a program. The program according to this embodiment can be stored, for example, in a non-temporary information storage device (information storage medium) which is a medium readable by a computer. The information storage device can be implemented by, for example, an optical disc, a memory card, an HDD, or a semiconductor memory. The semiconductor memory is, for example, ROM. The terminal control unit 110 of the terminal device 100, or the control unit 210 of the communication device 200, performs various processing according to this embodiment based on the program stored in the information storage device. That is, the information storage device stores a program that causes the computer to function as the terminal control unit 110 or the control unit 210. The computer is a device that includes an input device, a processing unit, a storage unit, and an output unit. Specifically, the program according to this embodiment is a program that causes the computer to execute each of the steps described above using Figures 7, 8, etc.

[0094] 3. Second Embodiment Figure 9 is a schematic diagram illustrating the handover control in the second embodiment. As shown in Figure 9, the handover control here refers to the control for transitioning from the second state to the first state. In this case, a smooth handover is possible by transferring the settings of the 5G communication CM3 in the second state to the 5G communication CM4 in the second state.

[0095] Figure 10 is a diagram illustrating the processing flow of this embodiment. First, at the start of this process, as shown in step S501, communication in the second state takes place, namely Wi-Fi communication between terminal device 100 and communication device 200, and 5G communication between communication device 200 and second communication device 300. Furthermore, the 5G communication between communication device 200 and second communication device 300 is communication using slices corresponding to URLLC, for example, and terminal device 100 is in a state where it can utilize the performance of 5G communication.

[0096] In step S502, the communication device 200 transmits a signal to the terminal device 100 instructing it to measure information about the surrounding base station. In step S503, the terminal device 100 measures the information about the base station and transmits the measurement results to the communication device 200. For example, the terminal device 100 obtains as measurement results information about 5G quality with the gNB including the second communication device 300 and information representing Wi-Fi quality with the AP including the communication device 200.

[0097] For example, in the second state, steps S502 and S503 are performed periodically. That is, the communication device 200 periodically monitors the communication quality of the 5G communication and Wi-Fi communication of the terminal device 100. The process in step S503 may involve sending the values ​​of the 5G quality and Wi-Fi quality themselves, or it may involve sending only whether or not an event occurred. For example, if the terminal device 100 determines that the Wi-Fi quality is higher than the 5G quality, it can maintain the second state and therefore determines that there is no event. On the other hand, if the terminal device 100 determines that the 5G quality is equal to or better than the Wi-Fi quality, in step S504, the terminal device 100 sends an event to the communication device 200 indicating that an event has occurred.

[0098] If no event occurs, the Wi-Fi quality will be higher than the 5G quality, so it is acceptable to maintain the second state. Therefore, in this case, the processing from step S504 onwards will not be executed.

[0099] On the other hand, if an event is notified, the 5G quality will be higher than the Wi-Fi quality, so there is a high probability that higher quality communication can be performed by transitioning to the first state. Therefore, in step S505, the communication device 200 decides to perform a handover. As in the first embodiment, the entity that determines the communication quality is not limited to the terminal device 100. For example, the control unit 210 may obtain information from the terminal device 100 representing the communication quality of the first communication method (5G quality) and the communication quality of the second communication method (Wi-Fi quality), and if it determines that the communication quality of the first communication method is higher than that of the second communication method, it may perform a handover control from the second state to the first state. In this way, the communication device 200 can determine whether or not to perform a handover. Since the communication device 200 is a device that can communicate with both the terminal device 100 and the second communication device 300, it is possible to transmit appropriate information to each device.

[0100] If a handover is decided upon, in step S506, the communication device 200 requests a handover from the second communication device 300. For example, the control unit 210 sends a request via the first communication unit 230 that includes information identifying the terminal device 100 (e.g., MAC address) and connection setting information specifying the slice corresponding to URLLC (e.g., S-NSSAI). The control unit 210 may also perform the process of receiving the MAC address in steps S503 or S504, or it may receive the MAC address in a different communication. In the second state, since the first communication unit 230 and the second communication device 300 are performing 5G communication, the control unit 210 can obtain the current connection setting information by referring to the control information of the first communication unit 230. Similar to the first embodiment, the communication device 200 and the second communication device 300 may send and receive information identifying the device by using the Xn interface function between gNBs, or they may register information about surrounding adjacent cells in advance. In other words, the control unit 210 can appropriately identify the second communication device 300, which is the handover destination for the terminal device 100.

[0101] In step S507, the communication device 200 instructs the terminal device 100 to perform a handover. The information transmitted in step S507 may include, for example, connection setting information that identifies the slice and an instruction to perform 5G communication to the second communication device 300 using that slice.

[0102] In step S508, terminal device 100 responds to the handover instruction. Terminal device 100 then establishes 5G communication with second communication device 300 and disconnects Wi-Fi communication with communication device 200.

[0103] As a result, as shown in step S509, the terminal device 100 and the second communication device 300 are directly connected via 5G using the desired slice. The detailed operation of each device in the process shown in Figure 10 will be explained below using the flowcharts in Figures 11 and 12. Note that the second communication device 300 only needs to process the 5G communication connection request from the terminal device 100, so a detailed explanation using the flowchart will be omitted.

[0104] Figure 11 is a flowchart illustrating the processing of the communication device 200. First, in step S601, the control unit 210 monitors the communication quality of the terminal device 100. Here, the communication quality refers to, for example, the 5G quality and Wi-Fi quality mentioned above. For example, the communication device 200 acquires the measurement results from the terminal device 100.

[0105] In step S602, the control unit 210 determines whether the 5G quality is equal to or better than the Wi-Fi quality. If the Wi-Fi quality is higher (No in step S602), the control unit 210 returns to step S601 and continues processing. In other words, the control unit 210 continues monitoring while maintaining the second state until the 5G quality becomes equal to or better than the Wi-Fi quality.

[0106] If the 5G quality becomes equal to or better than Wi-Fi quality (Yes in step S602), in step S603, the control unit 210 decides to perform a handover. For example, in step S603, the control unit 210 may identify the second communication device 300 to which the handover will be performed, identify the MAC address of the terminal device 100, and so on.

[0107] In step S604, the control unit 210 requests a handover from the second communication device 300. Specifically, the control unit 210 may request the second communication device 300 to establish a PDU session between the terminal device 100 and the second communication device 300 according to the connection setting information. In this way, by prompting the appropriate selection of the PDU session, it becomes possible to carry over the connection settings from the second state to the first state. Considering that in 5GS it is possible for the UE to send a PDU session establishment request specifying S-NSSAI, the processing in step S604 may be a signal requesting that the PDU session establishment request from the corresponding UE not be rejected. Also, if the probability of rejecting the PDU session establishment request is low, the processing in step S604 itself may be omitted.

[0108] In step S605, the control unit 210 instructs the terminal device 100 to perform a handover. That is, the control unit 210 may request (instruct) the terminal device 100 to establish a PDU session between the terminal device 100 and the second communication device 300 in accordance with the connection setting information. Specifically, the control unit 210 transmits information including the connection setting information and instructs the terminal device 100 to establish 5G communication with the second communication device 300 using the slice corresponding to the connection setting information. As a result, 5G communication in accordance with the connection setting information is established between the terminal device 100 and the second communication device 300.

[0109] Furthermore, after instructing the terminal device 100 to perform a handover in step S605, the control unit 210 may disconnect communication between the second communication unit 240 and the terminal device 100 in step S606. For example, the instruction in step S605 may include an instruction to the terminal device 100 to disconnect Wi-Fi communication with the communication device 200 (second communication unit 240), and the processing in step S606 may be executed starting from the control on the terminal device 100 side based on this instruction. In this way, when the handover from the second state to the first state is completed, it becomes possible to disconnect Wi-Fi connections that are not needed.

[0110] Figure 12 is a flowchart illustrating the processing of the terminal device 100. Here, we describe an example in which, in step S701, the second terminal communication unit 140 performs Wi-Fi communication with the communication device 200, and the communication device 200 and the second communication device 300 perform 5G communication using slices corresponding to URLLC, thereby enabling the terminal device 100 to utilize the URLLC function.

[0111] In step S702, the terminal control unit 110 uses the first terminal communication unit 130 and the second terminal communication unit 140 to acquire information representing 5G quality and Wi-Fi quality. In step S703, it determines whether the Wi-Fi quality has deteriorated compared to the 5G quality. If the Wi-Fi quality is higher than the 5G quality (No in step S703), the terminal control unit 110 returns to step S702 and continues monitoring the communication quality.

[0112] If the 5G quality is determined to be equal to or better than Wi-Fi quality (Yes in step S703), in step S704, the terminal control unit 110 reports the occurrence of the event to the communication device 200 via the second terminal communication unit 140. As a result, the communication device 200 decides to perform a handover.

[0113] In step S705, the terminal control unit 110 receives a handover instruction from the communication device 200 via the second terminal communication unit 140. This handover instruction corresponds to step S507 in Figure 10 and step S605 in Figure 11. The handover instruction may also be an instruction to establish 5G communication with the second communication device 300 and an instruction to disconnect Wi-Fi communication with the communication device 200.

[0114] In step S706, the terminal control unit 110 establishes 5G communication with the second communication device 300 via the first terminal communication unit 130. For example, the terminal control unit 110 sends a request to the second communication device 300 to establish a PDU session specifying the slice identified by the connection setting information. In step S707, the terminal control unit 110 disconnects the Wi-Fi communication with the second communication device 300 via the second terminal communication unit 140. Note that steps S706 and S707 are not limited to being executed in this order. For example, the Wi-Fi communication may be disconnected first, and then the 5G communication may be established.

[0115] As described above, in the second state, the control unit 210 may acquire information representing the settings in the communication between the first communication unit 230 and the second communication device 300 (5G communication CM3) as connection setting information. The control unit 210 performs handover control from the second state to the first state by disconnecting the communication between the second communication unit 240 and the terminal device 100 (step S606 in Figure 11) and requesting the establishment of communication between the terminal device 100 and the second communication device 300 using the first communication method based on the connection setting information (steps S604, S605). In this way, the settings in 5G communication CM3 in Figure 9 can be transferred to 5G communication CM4, so that even if a handover occurs, the performance of the first communication method can be appropriately utilized. More specifically, in the second state, even though the terminal device 100 is not directly using the first communication method, by using connection setting information corresponding to the communication between the communication device 200 and the second communication device 300, it is possible to maintain a state in which the performance of the first communication method can be utilized before and after the handover.

[0116] Furthermore, the method of this embodiment can be applied to a terminal device 100 including a terminal control unit 110, a first terminal communication unit 130, and a second terminal communication unit 140. In the second state, the terminal control unit 110 performs a handover from the second state to the first state by establishing communication between the first terminal communication unit and the second communication device (steps S507 to S509 in Figure 10) based on connection setting information representing the settings for communication between the communication device 200 and the second communication device 300 using the first communication method.

[0117] Furthermore, the method of this embodiment can be applied to a communication system 10 including a terminal device 100 and a communication device 200, a communication control method, a program that causes a computer to function as at least one of the terminal control unit 110 and control unit 210, etc., similar to the first embodiment.

[0118] 4. Variations The following describes some variations.

[0119] <Other examples of connection settings information> The above describes an example where connection configuration information identifies a network slice in 5GS. However, the connection configuration information in this embodiment is not limited to this. For example, the connection configuration information may be information that determines QoS (Quality of Service) in 5GS. Even when using QoS, it becomes possible to appropriately utilize the functions of 5GS based on the connection configuration information.

[0120] For example, in 5GS, one or more QoS flows are defined within a single PDU session, and the QoS is determined for each QoS flow. The connection configuration information in this embodiment is, for example, information for determining the QoS, and more specifically, it may be 5QI (5G QoS Indicator). 5QI is a scalar value, and a given value is associated with, for example, a combination of standard QoS characteristics. Hereinafter, the scalar value of 5QI will be referred to as the 5QI value. For example, each 5QI value is associated with the resource type, priority level, upper limit of packet forwarding delay, upper limit of packet error rate, etc. The resource type is information that identifies types such as bitrate guaranteed, delay critical bitrate guaranteed, and bitrate unguaranteed. The priority level is the priority in the allocation scheduling of forwarding resources between QoS flows, and a smaller value indicates higher priority.

[0121] For example, in this embodiment, the 5QI value in the first communication method before the handover may be acquired as connection setting information, and communication using the first communication method after the handover may be established based on this connection setting information. In this way, it becomes possible to maintain the same level of QoS before and after the handover.

[0122] <Second Connection Settings Information> Furthermore, the above describes an example of using connection setting information that represents the settings for communication using the first communication method in order to take advantage of the performance of the first communication method. However, as can be seen from Figure 1B, in the second state, the second communication method is used for communication between the terminal device 100 and the communication device 200. Therefore, by optimizing the settings of the second communication method to match those of the first communication method, it becomes possible to further improve the quality of communication between the terminal device 100 and the second communication device 300 in the second state.

[0123] For example, the control unit 210 of the communication device 200 may acquire second connection setting information, which is the setting for the second communication method, based on the connection setting information. Then, in the handover control from the first state to the second state, the control unit 210 communicates with the terminal device 100 via the second communication unit 240 according to the settings corresponding to the second connection setting information.

[0124] The second connection configuration information may also be information that determines QoS (Quality of Service) or communication bandwidth. This makes it possible to appropriately adjust the communication quality, etc., in the second communication method. For example, if the second communication method conforms to IEEE 802.11, IEEE 802.11e has been established as a standard for realizing QoS. IEEE 802.11e uses a method called EDCA (Enhanced Distributed Channel Access), for example. In EDCA, packets are classified into multiple access categories, and packets are transmitted according to the priority of each access category. For example, there are four access categories, and four levels of priority can be set. In EDCA, the minimum and maximum values ​​of CW (Contention Window) can be set according to the priority. Since CW is a parameter that determines the transmission waiting time, the higher the priority, the smaller the CW. In other words, in LBT (Listen before talk), the higher the priority, the shorter the LBT length (waiting time) is set. IEEE 802.11e may also use HCCA (Hybrid coordination function Controlled Channel Access). In HCCA, the access point sends a control frame to the terminal, and only the terminal that obtains transmission rights through the control frame can use the channel for the period specified in the control frame. In other words, communication priority can be controlled based on the frequency of transmission rights allocation and the transmission time. In this embodiment, the communication device 200 sends a control frame to the terminal device 100. The communication device 200 may also be able to control the communication bandwidth for each STA in Wi-Fi communication. Controlling the communication bandwidth may be control of the communication speed, control of the maximum amount of data allowed within a predetermined period, or control of the frequency band used for communication.

[0125] For example, if the second connection setting information is information representing the four priority levels in EDCA, and the connection setting information is a 5QI value, the control unit 210 acquires information representing the level corresponding to the 5QI value as the second connection setting information. For example, since priority levels are associated with the 5QI value, the terminal storage unit 120 has in advance information that divides the priority level into four levels. Then, when the 5QI value of the connection setting information is determined, the control unit 210 determines which of the four levels the corresponding priority level belongs to, and determines the priority in EDCA as the second connection setting information according to the determination result. The same applies when the second connection setting information is HCCA, and the control unit 210 determines control information as the second connection setting information that, for example, the higher the priority level for the 5QI value, the higher the frequency of transmission right allocation, or the longer the transmission time, or both. The second connection setting information may also be information representing the communication speed that is permitted for each terminal device 100 or application.

[0126] Furthermore, if the connection setting information specifies a particular network slice, the control unit 210 determines second connection setting information that gives a higher priority to communication compared to the case where no network slice is specified. For example, if the connection setting information specifies one of the eMMB, URLLC, or MIoT slices, the control unit 210 determines second connection setting information that gives a higher priority in EDCA compared to the case where any other slice is specified or where no slice is specified. However, network slices can be configured with a complex combination of various elements such as communication speed, reliability, and latency, and it may be difficult to control these depending on the second communication method. Therefore, the control unit 210 may perform control to determine second connection setting information when the connection setting information specifies QoS, and may omit control to determine second connection setting information when the connection setting information specifies a network slice.

[0127] The process of obtaining the second connection setting information based on the connection setting information is not limited to being performed by the control unit 210, but may also be performed by the terminal control unit 110.

[0128] Although this embodiment has been described in detail above, it will be readily apparent to those skilled in the art that many modifications are possible without substantially departing from the novel aspects and effects of this embodiment. Therefore, all such modifications are included within the scope of this disclosure. For example, any term that appears at least once in the specification or drawings together with a broader or synonymous term may be replaced with that different term anywhere in the specification or drawings. Furthermore, all combinations of this embodiment and its modifications are also included within the scope of this disclosure. In addition, the configuration and operation of terminal devices, communication devices, second communication devices, etc., are not limited to those described in this embodiment, and various modifications are possible. [Explanation of Symbols]

[0129] 10...Communication system, 100...Terminal device, 110...Terminal control unit, 120...Terminal memory unit, 130...First terminal communication unit, 140...Second terminal communication unit, 200...Communication device, 210...Control unit, 220...Memory unit, 230...First communication unit, 240...Second communication unit, 300...Second communication device, 400...Core network, A1...5G cell, A2...Wi-Fi cell, CM1~CM4...5G communication

Claims

1. A first communication unit that performs communication using the first communication method, A second communication unit that performs communication using a second communication method different from the first communication method, A control unit that controls the first communication unit and the second communication unit, Includes, The state in which the terminal device and the second communication device are communicating using the first communication method without going through a communication device is defined as the first state. When the terminal device and the second communication device are not communicating using the first communication method without going through the communication device, and the first communication unit communicates with the second communication device using the first communication method, and the second communication unit communicates with the terminal device, thereby relaying communication between the terminal device and the second communication device, the second state is defined as: The control unit, A communication device that, when a handover occurs between the first state and the second state, executes control to continue communication using the first communication method after the handover with the same settings as before the handover, based on connection setting information representing the settings for communication using the first communication method before the handover.

2. A first communication unit that performs communication using the first communication method, A second communication unit that performs communication using a second communication method different from the first communication method, A control unit that controls the first communication unit and the second communication unit, Includes, The state in which the terminal device and the second communication device are communicating using the first communication method without going through a communication device is defined as the first state. When the terminal device and the second communication device are not communicating using the first communication method without going through the communication device, and the first communication unit communicates with the second communication device using the first communication method, and the second communication unit communicates with the terminal device, thereby relaying communication between the terminal device and the second communication device, the second state is defined as: The control unit, When a handover occurs between the first state and the second state, control is executed to perform communication using the first communication method after the handover with the same settings as before the handover, based on connection setting information representing the settings for communication using the first communication method before the handover. The control unit, In the first state, information representing the settings for communication between the terminal device and the second communication device using the first communication method is acquired as the connection setting information. A communication device that communicates with the terminal device via the second communication unit and performs the handover from the first state to the second state by communicating with the second communication device via the first communication unit based on the connection setting information.

3. In claim 1 or 2, The control unit, A communication device that receives the connection setting information from the second communication device via the first communication unit.

4. In claim 3, The control unit, A communication device that controls the selection of a PDU (Protocol Data Unit) session based on the aforementioned connection setting information.

5. In claim 1, The control unit, In the second state, information representing the settings for communication between the first communication unit and the second communication device is acquired as the connection setting information. A communication device that performs the handover from the second state to the first state by disconnecting communication between the second communication unit and the terminal device, and requesting the establishment of communication between the terminal device and the second communication device using the first communication method based on the connection setting information.

6. In claim 5, The control unit, A communication device that obtains information from the terminal device representing the communication quality of the first communication method and the communication quality of the second communication method, and performs the handover from the second state to the first state when it determines that the communication quality of the first communication method is higher than that of the second communication method.

7. A first communication unit that performs communication using the first communication method, A second communication unit that performs communication using a second communication method different from the first communication method, A control unit that controls the first communication unit and the second communication unit, Includes, The state in which the terminal device and the second communication device are communicating using the first communication method is defined as the first state. When the first communication unit communicates with the second communication device using the first communication method, and the second communication unit communicates with the terminal device, thereby relaying communication between the terminal device and the second communication device, the second state is defined as: The control unit, When a handover occurs between the first state and the second state, control is executed to perform communication using the first communication method after the handover with the same settings as before the handover, based on connection setting information representing the settings for communication using the first communication method before the handover. The control unit, In the second state, information representing the settings for communication between the first communication unit and the second communication device is acquired as the connection setting information. The handover from the second state to the first state is performed by disconnecting communication between the second communication unit and the terminal device, and requesting the establishment of communication between the terminal device and the second communication device using the first communication method based on the connection setting information. The control unit, A communication device that requests at least one of the terminal device and the second communication device to establish communication between the terminal device and the second communication device using a PDU (Protocol Data Unit) session corresponding to the connection setting information.

8. In any one of claims 5 to 7, A communication device that, after instructing the terminal device to perform the handover, disconnects communication between the second communication unit and the terminal device.

9. In any one of claims 1 to 8, The first communication method is a communication device that is a wireless communication method used in 5GS (5G System).

10. In claim 9, The aforementioned connection settings information is: A communication device that provides information for determining network slices in the aforementioned 5GS network slicing, or information for determining QoS (Quality of Service).

11. In any one of claims 1 to 10, The control unit, A communication device that, based on the connection setting information, acquires second connection setting information, which is the setting for the second communication method, and communicates with the terminal device via the second communication unit according to the setting corresponding to the second connection setting information.

12. In claim 11, The second connection setting information is a communication device that determines the QoS (Quality of Service) or communication bandwidth.

13. A first terminal communication unit that performs communication using the first communication method, A second terminal communication unit that performs communication using a second communication method different from the first communication method, A terminal control unit that controls the first terminal communication unit and the second terminal communication unit, Includes, The first state is defined as the state in which the second terminal communication unit and the communication device are not communicating, and the first terminal communication unit and the second communication device are communicating. When the first terminal communication unit and the second communication device are not communicating using the first communication method without going through the communication device, and the second terminal communication unit is communicating with the communication device, and the communication device and the second communication device are communicating using the first communication method, and the state in which the communication device relays communication with the second communication device is defined as the second state, The terminal control unit, A terminal device that, when a handover occurs between the first state and the second state, executes control to continue communication using the first communication method after the handover with the same settings as before the handover, based on connection setting information representing the settings for communication using the first communication method before the handover.

14. In claim 13, The terminal control unit, A terminal device that performs the handover from the second state to the first state by establishing communication between the first terminal communication unit and the second communication device based on the connection setting information representing the settings for communication between the communication device and the second communication device using the first communication method in the second state.

15. In claim 13, The aforementioned communication device is Based on the connection setting information representing the settings for communication between the first terminal communication unit and the second communication device using the first communication method in the first state, the second communication device communicates with the first communication unit. The terminal control unit, A terminal device that performs the handover from the first state to the second state by establishing communication between the second terminal communication unit and the communication device.

16. Terminal device and Communication equipment and Includes, The first state is defined as a state in which the aforementioned communication device and the aforementioned terminal device are not communicating, and the aforementioned terminal device and the second communication device are communicating using the first communication method. When the terminal device and the second communication device do not communicate using the first communication method without going through the communication device, and the communication device communicates with the second communication device using the first communication method, and the communication device communicates with the terminal device using the second communication method, and the state in which the communication device relays communication between the terminal device and the second communication device is defined as the second state, The aforementioned communication device is A communication system that, when a handover occurs between the first state and the second state, executes control to continue communication using the first communication method after the handover with the same settings as before the handover, based on connection setting information representing the settings for communication using the first communication method before the handover.

17. Terminal device and Communication equipment and Includes, The first state is defined as a state in which the aforementioned communication device and the aforementioned terminal device are not communicating, and the aforementioned terminal device and the second communication device are communicating using the first communication method. When the terminal device and the second communication device do not communicate using the first communication method without going through the communication device, and the communication device communicates with the second communication device using the first communication method, and the communication device communicates with the terminal device using the second communication method, and the state in which the communication device relays communication between the terminal device and the second communication device is defined as the second state, The aforementioned communication device is When a handover occurs between the first state and the second state, control is executed to perform communication using the first communication method after the handover with the same settings as before the handover, based on connection setting information representing the settings for communication using the first communication method before the handover. The aforementioned communication device is In the first state, information representing the settings for communication between the terminal device and the second communication device using the first communication method is acquired as the connection setting information. A communication system that performs the handover from the first state to the second state by communicating with the terminal device using the second communication method and communicating with the second communication device using the first communication method based on the connection setting information.

18. Terminal device and Communication equipment and Includes, The first state is defined as a state in which the aforementioned communication device and the aforementioned terminal device are not communicating, and the aforementioned terminal device and the second communication device are communicating using the first communication method. When the communication device communicates with the second communication device using the first communication method, and the communication device communicates with the terminal device using the second communication method, and the state in which the communication device relays communication between the terminal device and the second communication device is defined as the second state, The aforementioned communication device is When a handover occurs between the first state and the second state, control is executed to perform communication using the first communication method after the handover with the same settings as before the handover, based on connection setting information representing the settings for communication using the first communication method before the handover. In the second state, information representing the settings for communication between the communication device and the second communication device using the first communication method is acquired as the connection setting information. The handover from the second state to the first state is performed by disconnecting the communication between the communication device and the terminal device using the second communication method, and requesting the establishment of communication between the terminal device and the second communication device using the first communication method based on the connection setting information. A communication system that requires at least one of the terminal device and the second communication device to establish communication between the terminal device and the second communication device using a PDU (Protocol Data Unit) session corresponding to the connection setting information.

19. The first state is defined as a state in which the communication device and the terminal device are not communicating, and the terminal device and the second communication device are communicating using the first communication method. When the terminal device and the second communication device do not communicate using the first communication method without going through the communication device, and the communication device communicates with the second communication device using the first communication method, and the communication device communicates with the terminal device using the second communication method, and the state in which the communication device relays communication between the terminal device and the second communication device is defined as the second state, When a handover occurs between the first state and the second state, control is executed to continue communication using the first communication method after the handover with the same settings as before the handover, based on connection setting information representing the settings for communication using the first communication method before the handover. Communication control method.

20. The first state is defined as a state in which the communication device and the terminal device are not communicating, and the terminal device and the second communication device are communicating using the first communication method. When the terminal device and the second communication device do not communicate using the first communication method without going through the communication device, and the communication device communicates with the second communication device using the first communication method, and the communication device communicates with the terminal device using the second communication method, and the state in which the communication device relays communication between the terminal device and the second communication device is defined as the second state, When a handover occurs between the first state and the second state, control is executed to perform communication using the first communication method after the handover with the same settings as before the handover, based on connection setting information representing the settings for communication using the first communication method before the handover. The aforementioned communication device In the first state, information representing the settings for communication between the terminal device and the second communication device using the first communication method is acquired as the connection setting information. The handover from the first state to the second state is performed by communicating with the terminal device using the second communication method and communicating with the second communication device using the first communication method based on the connection setting information. Communication control method.

21. The first state is defined as a state in which the communication device and the terminal device are not communicating, and the terminal device and the second communication device are communicating using the first communication method. When the communication device communicates with the second communication device using the first communication method, and the communication device communicates with the terminal device using the second communication method, and the state in which the communication device relays communication between the terminal device and the second communication device is defined as the second state, When a handover occurs between the first state and the second state, control is executed to perform communication using the first communication method after the handover with the same settings as before the handover, based on connection setting information representing the settings for communication using the first communication method before the handover. The aforementioned communication device In the second state, information representing the settings for communication between the communication device and the second communication device using the first communication method is acquired as the connection setting information. The handover from the second state to the first state is performed by disconnecting the communication between the communication device and the terminal device using the second communication method, and requesting the establishment of communication between the terminal device and the second communication device using the first communication method based on the connection setting information. The terminal device and the second communication device are required to establish communication between them using a PDU (Protocol Data Unit) session corresponding to the connection setting information. Communication control method.

Images