Wireless Communication Device and Communication Method

Abstract

This wireless communication device (10, 10A) comprises a first wireless communication unit (111), a second wireless communication unit (112) and a control unit (130). The first wireless communication unit (111) performs communications by connecting to a first communication network that permits the connection in a predetermined area. The second wireless communication unit (112) performs communications by connecting to a second communication network that is different from the first communication network. The control unit (130) predicts the communication quality of the communications performed by the first wireless communication unit (111), and determines, on the basis of whether or not the predicted communication quality satisfies a desired communication quality, whether or not to enable the second wireless communication unit (112) to perform communications.

Description

Technical Field

[0001] The present disclosure relates to a wireless communication device and a communication method.

Background Art

[0002] Studies are underway on next-generation mobile communication systems that can be used by various entities according to regional needs and individual needs. For example, in addition to the nationwide 5G service (public network) provided by mobile phone carriers, next-generation mobile communication systems include mechanisms that enable various entities such as regional companies and local governments to flexibly and sporadically construct and use a network (private network) in a predetermined area such as within their own buildings or sites. A terminal device that can be connected to both a private network and a public network may be included within a predetermined area.

[0003] On the other hand, when a terminal device can communicate simultaneously through a plurality of carriers by carrier aggregation, a technique for appropriately determining a search threshold corresponding to carrier aggregation and performing cell search and quality measurement is known.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, the above-described technique is for a terminal device that can communicate through a plurality of carriers to perform cell search, and is premised on the terminal device communicating with one network.

[0006] Thus, in the prior art, it has not been assumed that a wireless communication device (e.g., a terminal device) connects to a plurality of different networks, such as a Private Network and a public network. Therefore, when a wireless communication device can connect to a plurality of networks, a mechanism is required that enables the wireless communication device to perform communication that more continuously satisfies a desired communication quality (QoS: Quality of Service).

[0007] Therefore, in the present disclosure, a mechanism is provided that enables a wireless communication device capable of connecting to a plurality of networks to perform communication that more continuously satisfies a desired communication quality.

[0008] Note that the above problem or objective is only one of the plurality of problems or objectives that can be solved or achieved by the plurality of embodiments disclosed in this specification.

Means for Solving the Problem

[0009] According to the present disclosure, a wireless communication device is provided. The wireless communication device includes a first wireless communication unit, a second wireless communication unit, and a control unit. The first wireless communication unit connects to and communicates with a first communication network that permits connection in a predetermined area. The second wireless communication unit connects to and communicates with a second communication network different from the first communication network. The control unit predicts the communication quality of the communication by the first wireless communication unit, and determines whether to perform communication by the second wireless communication unit based on whether the predicted communication quality satisfies a desired communication quality.

Brief Description of the Drawings

[0010]

Figure 1

Figure 2

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Figure 7

Embodiments for Carrying Out the Invention

[0011] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. In the present specification and drawings, components having substantially the same functional configuration are denoted by the same reference numerals, and redundant description is omitted.

[0012] Also, in the present specification and drawings, similar components of the embodiments may be distinguished by attaching different alphabets or numbers after the same reference numeral. However, when it is not necessary to particularly distinguish each of the similar components, only the same reference numeral is attached.

[0013] One or more of the embodiments (including examples and modifications) described below can each be implemented independently. On the other hand, at least a part of the plurality of embodiments described below may be implemented in appropriate combination with at least a part of other embodiments. These multiple embodiments may include different novel features from each other. Therefore, these multiple embodiments can contribute to solving different purposes or problems from each other and can exhibit different effects from each other.

[0014] <<1. Introduction>> As described above, studies on next-generation mobile communication systems that can be used by various entities according to regional and individual needs are underway. For next-generation mobile communication systems, for example, in addition to the nationwide 5G service (public network, Public Network) provided by mobile phone carriers, there are mechanisms that enable various entities such as regional companies and local governments to flexibly and spot-construct a network (Private Network) within a predetermined area such as their own buildings or sites and use it.

[0015] In conventional mobile communication systems (cellular systems), multiple cells are arranged such that the areas of each cell overlap. In this way, the conventional cellular system is designed to provide a network that enables communication anywhere.

[0016] In particular, in a public network (Public Network) that uses licensed bands, a large number of terminal devices are accommodated within a large number of cells. For example, when a large number of terminal devices concentrate in one cell provided by one base station device, the base station device performs scheduling (resource allocation) while considering fairness among the terminal devices within the cell.

[0017] As a result, the communication speed of each terminal device varies due to external factors such as the number of terminal devices accommodated in the cell, the traffic volume, and the frequency of traffic generation.

[0018] On the other hand, in a Private Network that uses licensed bands such as local 5G (hereinafter also simply referred to as Private Network), cells are configured only in locations where a license is granted. In a Private Network, a cell accommodates terminal devices that are permitted to connect to the Private Network within the area.

[0019] Therefore, in a Private Network, by restricting the number of connected terminal devices or performing scheduling based on the type of terminal device, it is possible to suppress fluctuations in communication speed caused by external factors in the public network.

[0020] In addition, the terminal device connected to the Private Network can achieve wide - area coverage by utilizing Roaming to the public network.

[0021] <1.1. An example of a communication system> Here, the outline of the communication system 1 according to the proposed technology of the present disclosure will be described. FIG. 1 is a diagram showing a configuration example of the communication system 1 according to the proposed technology of the present disclosure.

[0022] The communication system 1 shown in FIG. 1 includes a terminal device 10 and base station devices 20A and 20B.

[0023] (1) Base station device 20A The base station device 20A is included in the Private Network system and provides Private Network services to subordinate devices. Here, the Private Network system according to the present embodiment is a system that provides services using a licensed band (for example, the first frequency band f1) within a predetermined area. The base station device 20A is a base station device of a local 5G system. The base station device 20A performs wireless communication with a device (for example, the terminal device 10) located inside the cell C_A of the base station device 20A. The base station device 20A transmits a downlink signal to the terminal device 10 and receives an uplink signal from the terminal device 10.

[0024] In FIG. 1, the case where there is one base station device 20A included in the Private Network system is shown, but it is not limited to this. For example, the Private Network system may include a plurality of base station devices 20A.

[0025] In this case, the base station device 20A is logically connected to other base station devices 20A (not shown) via, for example, an X2 interface or an Xn interface, and can transmit and receive control information and the like with other base station devices 20A. The base station device 20A is logically connected to a so-called core network (not shown) via, for example, an S1 interface or an NG interface, and can transmit and receive control information and the like. Note that the communication between these devices can be physically relayed by various devices.

[0026] (2) Base station device 20B The base station device 20B is a communication device included in a public network system and provides public network services to subordinate devices. For example, the base station device 20A is a base station device of a cellular system. It performs wireless communication with a device (for example, the terminal device 10) located inside the cell C_B of the base station device 20B. The base station device 20B transmits a downlink signal to the terminal device 10 and receives an uplink signal from the terminal device 10.

[0027] The base station device 20B is logically connected to other base station devices 20B via, for example, an X2 interface, and can transmit and receive control information and the like. Also, the base station device 20B is logically connected to a so-called core network (not shown) via, for example, an S1 interface, and can transmit and receive control information and the like. Note that the communication between these devices can be physically relayed by various devices.

[0028] As described above, the public network is a network that enables communication anywhere. Therefore, in a public network system, a plurality of cells (base station devices 20B) are arranged so as to satisfy area coverage under the condition that out-of-band radiation is lower than a predetermined level.

[0029] In addition, multiple operators can each provide different public network services. Thus, the public network is not limited to one, and the terminal device 10 can be connected to multiple public networks. For example, in FIG. 1, the base station device 20B_1, the base station device 20B_2, and the base station device 20_3 may each belong to a different public network system. In this case, the base station devices 20B_1 to 20B_3 communicate with the subordinate devices using different frequency bands (the second frequency band f2 to the fourth frequency band f4). In the example of FIG. 1, the case where the terminal device 10 communicates with the base station device 20B_1 using the second frequency band f2 and communicates with the base station device 20B_2 using the third frequency band f3 is shown.

[0030] (3) Terminal device 10 The terminal device 10 is a wireless communication device capable of communicating in the Private Network system. The terminal device 10 performs wireless communication with the base station device 20A of the Private Network system. That is, the terminal device 10 is connected to the Private Network (an example of the first communication network) and performs wireless communication via the base station device 20A. For example, the terminal device 10 receives a downlink signal from the base station device 20A and transmits an uplink signal to the base station device 20A.

[0031] In addition, the terminal device 10 is a wireless communication device capable of communicating in the public network system. The terminal device 10 performs wireless communication with the base station device 20B of the public network system. That is, the terminal device 10 is connected to the public network (an example of the second communication network) and performs wireless communication via the base station device 20B. For example, the terminal device 10 receives a downlink signal from the base station device 20B and transmits an uplink signal to the base station device 20B.

[0032] In addition, the terminal device 10 is not limited to a so-called UE (User Equipment), and for example, a so-called low-cost UE such as an MTC terminal, an eMTC (Enhanced MTC) terminal, and an NB-IoT terminal may be applied. Further, an infrastructure terminal such as an RSU (Road Side Unit) or a terminal such as a CPE (Customer Premises Equipment) may be applied.

[0033] <1.2. Problem> As described above, in a Private Network system that uses a licensed band, for example, the base station device 20A manages the connected terminal device 10 and can perform scheduling to guarantee the communication speed and maximum delay within the coverage based on the type of the terminal device 10.

[0034] However, in a Private Network that uses a licensed band, a license is granted with a limited location (such as within owned land or buildings). Therefore, it is necessary to suppress interference to areas outside the license target, and at the boundary (cell edge) with the non-target area, the electric field strength becomes weak, and there is a problem that it is difficult to guarantee the communication speed and maximum delay.

[0035] As described above, since the Private Network system is operated with a limited area, it is necessary to reduce the interference to areas outside the licensed area to a predetermined level or less. At the edge of the coverage (cell edge), it is assumed that the communication quality is much worse than that of the public network.

[0036] In the case of a device that can be connected to both the Private Network and the public network like the terminal device 10 described above, a method of roaming from the Private Network to the public network at the cell edge can be considered. At this time, since it takes time to switch from the Private Network to the public network, there is a problem that the communication quality (QoS) is not satisfied in the case of traffic that requires low latency or continuous communication.

[0037] Thus, there is a need for a mechanism that allows a wireless communication device (e.g., terminal device 10) that can be connected to multiple networks (e.g., a private network and a public network) to continuously perform communication that satisfies QoS between the multiple networks. For example, when the connection destination of the terminal device 10 switches from a private network to a public network, there is a need for a mechanism that allows the terminal device 10 to continuously perform communication that satisfies a desired QoS.

[0038] <1.3. Outline of the proposed technology> Therefore, in the proposed technology of the present disclosure, when connected to a private network, the terminal device 10 predicts the communication quality (QoS), and determines whether to switch to a public network according to the predicted communication quality (hereinafter also referred to as predicted QoS). By switching between multiple networks according to the predicted QoS in this way, the terminal device 10 can switch the connection destination network before the actual QoS (hereinafter also referred to as actual QoS) fails to satisfy the desired QoS (hereinafter also referred to as desired QoS).

[0039] Here, with reference to FIG. 2, the outline of the communication process according to the proposed technology of the present disclosure will be described. FIG. 2 is a diagram for explaining the outline of the communication process according to the proposed technology of the present disclosure.

[0040] It is assumed that the terminal device 10 shown in FIG. 2 is connected to a private network and is communicating with the base station device 20A.

[0041] In this case, the terminal device 10 calculates the predicted QoS of the communication with the base station device 20A (step S1). For example, the terminal device 10 estimates the QoS after a predetermined period from the current time as the predicted QoS according to the actual QoS before the current time and the change in the actual QoS.

[0042] Next, the terminal device 10 determines whether the predicted QoS satisfies the desired QoS (step S2). If the desired QoS is satisfied (step S2; No), the process returns to step S1.

[0043] On the other hand, when the predicted QoS cannot satisfy the desired QoS (step S2; Yes), the terminal device 10 switches the connection destination from the Private Network to the public network (step S3). For example, the terminal device 10 switches the connection destination from the Private Network to the public network by communicating with the base station device 20B_2 whose QoS in communication with the public network as the connection destination satisfies the desired QoS.

[0044] The terminal device 10 connected to the public network and communicating with the base station device 20B determines whether or not it satisfies the switching condition from the public network to the Private Network (step S4). For example, the terminal device 10 measures the communication quality with the base station device 20A and determines whether or not it satisfies the switching condition according to whether or not the measured communication quality satisfies the desired quality.

[0045] For example, when the communication quality with the Private Network cannot satisfy the desired communication quality and the switching condition cannot be satisfied (step S4; No), it returns to step S4, and the terminal device 10 continues to determine whether or not it satisfies the switching condition. In this way, the terminal device 10 makes the determination regularly until the switching condition is satisfied.

[0046] On the other hand, for example, when the communication quality with the Private Network satisfies the desired communication quality, that is, when the switching condition is satisfied (step S4; Yes), the terminal device 10 switches the connection destination from the public network to the Private Network (NW) (step S5). Thereby, the terminal device 10 communicates with the base station device 20A.

[0047] In this way, by switching the connection destination from the Private Network to the public network according to the predicted QoS, the terminal device 10 can switch the connection destination from the Private Network to the public network before the actual QoS fails to satisfy the desired QoS. Thereby, the terminal device 10 can continuously perform communication that satisfies the actual QoS.

[0048] Also, when the communication quality with the Private Network meets the desired communication quality, the terminal device 10 switches the connection destination from the public network to the Private Network regardless of the communication quality with the public network. Thereby, the terminal device 10 can preferentially use the Private Network with more stable communication as the connection destination.

[0049] <<2. First Embodiment>> As a method for the terminal device 10 to connect to a plurality of networks, there are methods of selecting and connecting one from a plurality of networks, such as SSSS (Single SIM Single Standby) and DSSS (Dual SIM Single Standby).

[0050] Hereinafter, the first embodiment will be described for the case where the terminal device 10 connects to either the Private Network or the public network using SSSS or DSSS and performs communication.

[0051] <2.1. Configuration Example of Terminal Device> First, a configuration example of the terminal device 10 according to the first embodiment will be described.

[0052] The terminal device 10 is a wireless communication device that wirelessly communicates with other communication devices such as the base station device 20. The terminal device 10 is, for example, a mobile phone, a smart device (smartphone or tablet), a PDA (Personal Digital Assistant), or a personal computer. Also, the terminal device 10 may be an imaging device equipped with a communication function (e.g., a camcorder), or a vehicle such as a bike or a mobile relay vehicle equipped with a communication device such as an FPU (Field Pickup Unit). Further, the terminal device 10 may be an M2M (Machine to Machine) device or an IoT (Internet of Things) device. The terminal device 10 may be a router having a plurality of communication paths.

[0053] Further, the terminal device 10 may be capable of LPWA (Low Power Wide Area) communication with other communication devices (e.g., the base station device 20). Also, the wireless communication used by the terminal device 10 may be wireless communication using millimeter waves. Note that the wireless communication used by the terminal device 10 may be wireless communication using radio waves, or may be wireless communication (optical wireless) using infrared rays or visible light.

[0054] Further, the terminal device 10 may be a mobile device. A mobile device is a movable wireless communication device. At this time, the terminal device 10 may be a wireless communication device installed in a mobile body, or may be the mobile body itself. For example, the terminal device 10 may be a vehicle (Vehicle) moving on a road such as an automobile, a bus, a truck, or a motorcycle, or a wireless communication device mounted on the vehicle. Note that the mobile body may be a mobile terminal, or may be a mobile body moving on land, underground, on water, or underwater. Also, the mobile body may be a mobile body moving within the atmosphere such as a drone or a helicopter, or may be a mobile body moving outside the atmosphere such as an artificial satellite.

[0055] The terminal device 10 may simultaneously connect to a plurality of base station devices 20 or a plurality of cells to perform communication. For example, when one base station device 20 supports a communication area via a plurality of cells (e.g., pCell, sCell), by using carrier aggregation (CA) technology, dual connectivity (DC) technology, or multi-connectivity (MC) technology, it is possible to bundle those plurality of cells and communicate between the base station device 20 and the terminal device 10. Alternatively, it is also possible for the terminal device 10 to communicate with those plurality of base station devices 20 by using coordinated multi-point transmission and reception (CoMP) technology via cells of different base station devices 20.

[0056] FIG. 3 is a block diagram showing an example of the configuration of the terminal device 10 according to the first embodiment of the present disclosure. Referring to FIG. 3, the terminal device 10 includes a communication unit 110, a storage unit 120, and a control unit 130. Note that the configuration shown in FIG. 3 is a functional configuration, and the hardware configuration may be different from this. Further, the functions of the terminal device 10 may be implemented in a distributed manner in a plurality of physically separated configurations.

[0057] (1) Communication unit 110 The communication unit 110 is a communication interface for communicating with other devices, and includes first and second wireless communication units 111 and 112. The first wireless communication unit 111 is a communication interface for communicating with other devices. For example, the first wireless communication unit 111 is a network interface. The first wireless communication unit 111 is a communication unit that connects to a public network and performs wireless communication.

[0058] The second wireless communication unit 112 is a communication interface for communicating with other devices. For example, the second wireless communication unit 112 is a network interface. The second wireless communication unit 112 is a communication unit that connects to a Private Network and performs wireless communication.

[0059] The communication unit 110 communicates with the base station device 20 using one of the first and second wireless communication units 111 and 112 in accordance with an instruction from the control unit 130. For example, when the communication unit 110 performs wireless communication using the first wireless communication unit 111, the communication unit 110 communicates with the base station device 20B (see FIG. 1). Also, when the communication unit 110 performs wireless communication using the second wireless communication unit 112, the communication unit 110 communicates with the base station device 20A (see FIG. 1).

[0060] Here, it is assumed that the communication unit 110 switches between a plurality of wireless communication units to perform communication, but it may be configured to connect to a plurality of networks and perform communication using one wireless communication unit.

[0061] (2) Storage unit 120 The storage unit 120 is a storage device capable of reading and writing data, such as DRAM, SRAM, flash memory, and hard disk. The storage unit 120 functions as a storage means of the terminal device 10.

[0062] (3) Control unit 130 The control unit 130 is a controller that controls each part of the terminal device 10. The control unit 130 is realized by a processor such as a CPU or an MPU, for example. For example, the control unit 130 is realized by the processor executing various programs stored in a storage device inside the terminal device 10, using a RAM or the like as a work area. Note that the control unit 130 may be realized by an integrated circuit such as an ASIC or an FPGA. Any of the CPU, MPU, ASIC, and FPGA can be regarded as a controller. Also, the control unit 130 may be realized by a GPU in addition to or instead of the CPU.

[0063] The control unit 130 includes a traffic management unit 131, a communication control unit 132, a communication quality measurement unit 133, a radio parameter collection unit 134, a communication quality prediction unit 135, an NW (Network) search unit 136, and an NW switching determination unit 137. Each block (traffic management unit 131 to NW switching determination unit 137) constituting the control unit 130 is a functional block indicating the function of the control unit 130. These functional blocks may be software blocks or hardware blocks. For example, each of the above functional blocks may be one software module realized by software (including a microprogram), or one circuit block on a semiconductor chip (die). Of course, each functional block may be one processor or one integrated circuit. The control unit 130 may be configured with functional units different from the above functional blocks. The method of configuring the functional blocks is arbitrary.

[0064] (Traffic management unit 131) The traffic management unit 131 manages the traffic (uplink data) generated by the terminal device 10 and the traffic (downlink data) received from the base station device 20. For example, the traffic management unit 131 outputs the uplink data to be transmitted to the base station device 20 to the communication control unit 132. The traffic management unit 131 receives the downlink data received from the base station device 20 from the communication control unit 132.

[0065] Also, the traffic management unit 131 manages the communication quality required for the traffic (for example, the desired QoS), and notifies the desired QoS to the communication control unit 132 and the communication quality prediction unit 135.

[0066] Here, the communication quality managed by the traffic management unit 131 will be described using Table 1. Table 1 is a table for explaining an example of the relationship between the type of traffic and the required QoS (desired QoS).

[0067]

Table 1

[0068] Based on the correspondence information between the type of traffic and the desired QoS as shown in Table 1, the traffic management unit 131 manages the communication quality of the traffic. The correspondence information as shown in Table 1 is assumed to be stored in the storage unit 120, for example.

[0069] For example, "QoS-1" in Table 1 is an index indicating the desired throughput in the uplink. When the traffic is "Live streaming1", it is "UL 80Mbps". This indicates that when the traffic is "Live streaming1", a throughput of 80 Mbps or more is required in the uplink.

[0070] In addition, "QoS-2" in Table 1 is an indicator showing the desired throughput in the downlink. When the traffic is "Live streaming2", it is "DL 80Mbps". This indicates that when the traffic is "Live streaming2", a throughput of 1 Mbps or more is required in the downlink.

[0071] "QoS-3" in Table 1 is an indicator showing the delay. When the traffic is "Remote control", it is "Latency 2msec". This indicates that when the traffic is "Remote control", the allowable delay time is 2 msec or less.

[0072] "QoS-4" in Table 1 is an indicator showing the jitter. When the traffic is "VR" (Virtual Reality), it is "Jitter 20msec". This indicates that when the traffic is "VR", the allowable jitter is 20 msec or less.

[0073] "QoS-5" in Table 1 is an indicator showing the error rate. When the traffic is "Live streaming1", it is "error rate 10 -2 ". This indicates that when the traffic is "Live streaming1", the error rate is required to be 10 -2 or less.

[0074] In this way, the traffic management unit 131 manages the desired QoS for each type of traffic based on the correspondence information between the traffic type and the desired QoS stored in the storage unit 120.

[0075] Note that the desired QoS corresponding to traffic does not necessarily need to include all the indicators shown in Table 1. For example, as shown in Table 1, "QoS-4" corresponding to "Remote control" is not defined. Thus, the traffic management unit 131 manages at least some of the indicators shown in Table 1 as the desired QoS corresponding to traffic. Alternatively, the traffic management unit 131 may manage indicators other than those shown in Table 1 as the desired QoS.

[0076] Also, the traffic types shown in Table 1 are just examples, and the correspondence information may include traffic types other than those shown in Table 1. For example, when the traffic is video data, the desired QoS can be managed according to the resolution, fps, video compression method, etc.

[0077] The latency of "QoS-3" shown in Table 1 may be defined as the value of Round Trip Time (RRT), or may be defined as the one-way latency. Note that when the one-way latency is used as the indicator of "QoS-3", high-precision time synchronization is performed between the network and the terminal device 10. In this case, for example, the latency time in the uplink is fed back from the network side to the terminal device 10. Also, the latency time in the downlink is fed back from the terminal device 10 to the network side.

[0078] The error rate of "QoS-5" shown in Table 1 is an indicator representing the reliability of communication, and may be defined as the error rate of the first transmission, or may be defined as the error rate when retransmission is performed a predetermined number of times.

[0079] (Communication control unit 132) The communication control unit 132 shown in FIG. 3 controls the communication unit 110 to perform wireless communication with the base station device 20. When the communication control unit 132 connects to the public network for communication, it controls the first wireless communication unit 111 to communicate with the base station device 20B. When the communication control unit 132 connects to the Private Network for communication, it controls the second wireless communication unit 112 to communicate with the base station device 20A.

[0080] The communication control unit 132 selects either the public network or the Private Network as the network to connect according to the determination result by, for example, the NW switching determination unit 137.

[0081] The communication control unit 132 notifies the communication quality measurement unit 133 of information regarding communication quality. Further, the communication control unit 132 notifies the radio parameter collection unit 134 of information regarding radio parameters.

[0082] (Communication quality measurement unit 133) Based on the information regarding communication quality acquired from the communication control unit 132, the communication quality measurement unit 133 measures the communication quality with the network over which communication is being performed. The information regarding communication quality may include, for example, the following information. ·RSRP (Reference Signal Received Power) ·RSRQ (Reference Signal Received Quality) ·SINR (Signal to Interference plus Noise Ratio) or SNR (signal-noise ratio) ·RSSI (Received Signal Strength Indicator) ·pathloss ·Error rate (e.g., downlink / uplink BLER (Block Error Ratio))

[0083] In addition to the information described above, for example, the information regarding communication quality may include the delay time and amount of change, jitter time and amount of change, throughput information (statistics such as average, peak, 5%-ile, amount of change in throughput, etc.) that can be acquired at a higher level such as an application.

[0084] Alternatively, the information regarding communication quality may include, for example, information regarding the moving speed of the terminal device 10 or location information.

[0085] For example, when the communication control unit 132 is connected to the public network via the second wireless communication unit 112, the communication quality measurement unit 133 measures the communication quality with the public network. Also, when the communication control unit 132 is connected to the Private Network via the first wireless communication unit 111, the communication quality measurement unit 133 measures the communication quality with the Private Network.

[0086] The communication quality measurement unit 133 outputs the measured communication quality to the communication quality prediction unit 135.

[0087] (Wireless parameter collection unit 134) The wireless parameter collection unit 134 collects parameter information of the wireless communication performed by the communication unit 110 via the communication control unit 132.

[0088] The parameters collected by the wireless parameter collection unit 134 include, as an example, the following information. · Bandwidth (including information on the applicability of CA (Carrier aggregation) or DC (Dual Connectivity), for example) · RB (Resource Block) allocation information (such as statistical values for the past few seconds, for example) · Information regarding the MCS table (such as 64QAM or 256QAM, for example) · Information on the MCS used for communication (such as statistical values for the past few seconds, for example) · Information on the uplink BSR (buffer status report)

[0089] The wireless parameter collection unit 134 outputs the collected wireless parameters to the communication quality prediction unit 135.

[0090] (Communication quality prediction unit 135) The communication quality prediction unit 135 predicts the communication quality by the communication unit 110 using the communication quality measured by the communication quality measurement unit 133 and the wireless parameters collected by the wireless parameter collection unit 134.

[0091] The communication quality prediction unit 135 estimates predicted QoS, for example, as a prediction of communication quality. The predicted QoS is, for example, the QoS after a predetermined period has elapsed from the current time. The communication quality prediction unit 135 calculates, as the predicted QoS, the QoS after a predetermined period has elapsed from, for example, the amount of change in the actual QoS before the current time.

[0092] The predicted QoS may be the same index as the desired QoS described using Table 1, or may be an index other than those in Table 1. Also, the communication quality prediction unit 135 may estimate the predicted QoS for all of the QoS indices shown in Table 1, for example, or may estimate at least one index such as delay as the predicted QoS.

[0093] The communication quality prediction unit 135 may estimate, as the predicted QoS, a typical index obtained according to the type of traffic. For example, in the case of traffic that requires low latency such as "Remote control", the communication quality prediction unit 135 may estimate a delay time such as RTT or jitter as the predicted QoS. Also, in the case of traffic that requires guaranteeing the communication speed in at least one of the downlink and uplink, the communication quality prediction unit 135 estimates the throughput as the predicted QoS.

[0094] When the communication quality prediction unit 135 uses the communication speed as an index of the predicted QoS, for example, it calculates the communication speed with the connected network as the predicted QoS. Alternatively, the communication quality prediction unit 135 may calculate the reception quality and the moving speed as the predicted QoS.

[0095] Also, when the terminal device 10 is connected to a Private Network and communicating, the communication quality prediction unit 135 determines whether the communication by the communication unit 110 satisfies the desired QoS after a predetermined period has elapsed from the current time based on the predicted QoS and the desired QoS. In other words, the communication quality prediction unit 135 determines whether the terminal device 10 is located at the edge of the coverage and whether the communication quality with the Private Network deteriorates after a predetermined time has elapsed from the current time.

[0096] The communication quality prediction unit 135 determines whether the communication by the communication unit 110 satisfies the desired QoS after a predetermined period has elapsed from the current time, for example, by determining whether the predicted QoS satisfies the desired QoS.

[0097] Alternatively, the communication quality prediction unit 135 may predict the timing at which the QoS will no longer satisfy the desired QoS from the predicted QoS. If the predicted timing is shorter than the predetermined period, the communication quality prediction unit 135 determines that the predicted QoS will not satisfy the desired QoS after the predetermined period has elapsed.

[0098] Further, the communication quality prediction unit 135 may determine whether the predicted QoS can satisfy the desired QoS continuously for a certain period.

[0099] Note that the communication quality prediction unit 135 may calculate the predicted QoS using, for example, machine learning that takes as input the measurement results by the communication quality measurement unit 133 and the radio parameters collected by the radio parameter collection unit 134. The communication quality prediction unit 135 may determine whether the predicted QoS satisfies the desired QoS using, for example, machine learning that takes the predicted QoS as input. Alternatively, the communication quality prediction unit 135 may determine whether the predicted QoS satisfies the desired QoS using, for example, machine learning that takes as input the measurement results by the communication quality measurement unit 133 and the radio parameters collected by the radio parameter collection unit 134.

[0100] Here, it is assumed that the communication quality prediction unit 135 estimates the QoS after a predetermined period has elapsed from the current time as the predicted QoS. In this case, the predetermined period is, for example, a pre-determined period. The predetermined period may be set according to the time required for the terminal device 10 to switch the network, for example. The time required for the network switch may be calculated in advance by simulation or the like, or may be calculated based on the time taken for the previous switch. Alternatively, the predetermined period may be changed according to the change amount of the actual QoS.

[0101] The communication quality prediction unit 135 notifies the determination result to the NW search unit 136 and the NW switching determination unit 137.

[0102] (NW search unit 136) When the communication quality prediction unit 135 determines that the predicted QoS cannot meet the desired QoS, the NW search unit 136 searches for the Roaming destination Network. For example, the NW search unit 136 receives band information (such as frequency band and bandwidth) and notification information (such as SIB1) from the public network base station device 20B via the first wireless communication unit 111, and acquires cell information and information related to communication quality. In this way, the NW search unit 136 performs a cell search according to the determination result of the communication quality prediction unit 135.

[0103] When the communication unit 110 is connected to the public network and communicating, the NW search unit 136 periodically performs a cell search for the Private Network. In this case, the NW search unit 136 receives band information (such as frequency band and bandwidth) and notification information (such as SIB1) from the Private Network base station device 20A, and acquires cell information and information related to communication quality.

[0104] The NW search unit 136 notifies the result of the cell search to the NW switching determination unit 137.

[0105] (NW switching determination unit 137) The NW switching determination unit 137 determines whether to switch the communication destination Network.

[0106] For example, when the communication unit 110 is connected to the Private Network and communicating, assume that the communication quality prediction unit 135 determines that the predicted QoS cannot meet the desired QoS. In this case, the NW switching determination unit 137 determines whether to switch the connection destination from the Private Network to the public network according to the switching conditions.

[0107] Based on the search result of the NW search unit 136, the NW switching determination unit 137 calculates the QoS of the public network. When the calculated QoS of the public network meets the desired QoS, the NW switching determination unit 137 determines to switch the connection destination from the Private Network to the public network (roaming destination). Alternatively, when it is estimated that the QoS will be improved by switching to the public network, the NW switching determination unit 137 determines to switch the connection destination from the Private Network to the public network (roaming destination). For example, when the calculated QoS of the public network is better than the predicted QoS, the NW switching determination unit 137 determines that the QoS will be improved by switching to the public network.

[0108] When the NW switching determination unit 137 determines to switch the connection destination from the Private Network to the public network (roaming destination), it notifies the communication control unit 132 to switch the connection destination. Thereby, the communication control unit 132 switches the connection destination from the Private Network to the public network and performs communication.

[0109] Alternatively, when the NW switching determination unit 137 determines to switch the connection destination from the Private Network to the public network (roaming destination), it may present information recommending the switching of the connection destination to the user. In this case, the communication control unit 132 switches the connection destination according to an instruction from the user.

[0110] Note that the NW switching determination unit 137 may determine whether to perform Roaming using the currently used SIM, that is, whether to perform Roaming on a public network with Roaming history. Alternatively, the NW switching determination unit 137 may determine whether to perform Roaming on a predetermined public network. That is, the NW switching determination unit 137 may prevent a non-Roamable public network from being selected as the connection destination by not determining whether to perform Roaming on a non-Roamable public network. The NW switching determination unit 137 may identify a public network, for example, by a combination of a country code (MCC) and a carrier code (MNC) (PLMN (Public Land Mobile Network)).

[0111] On the other hand, when the communication unit 110 is connected to a public network and communicating, the NW switching determination unit 137 determines whether to switch the connection destination based on the cell search result of the Private Network by the NW search unit 136.

[0112] In this case, the NW switching determination unit 137 calculates the QoS of the Private Network based on the search result of the NW search unit 136. When the calculated QoS of the Private Network satisfies the desired QoS, the NW switching determination unit 137 determines to return (switch) the connection destination from the public network (Roaming destination) to the Private Network. Alternatively, when it is estimated that the QoS will be improved by returning to the Private Network, the NW switching determination unit 137 determines to return the connection destination from the public network (Roaming destination) to the Private Network. The NW switching determination unit 137 determines that the QoS will be improved by returning to the Private Network, for example, when the calculated QoS of the Private Network is better than the predicted QoS of the public network.

[0113] In this way, the NW switching determination unit 137 determines whether to switch the connection destination back to the Private Network based on the QoS (communication quality) of the Private Network. As a result, when the communication quality of the Private Network is improved, the connection destination of the terminal device 10 can be switched back to the Private Network more quickly.

[0114] <2.2. Switching Process> <2.2.1. Switching Process to the Public Network> Next, with reference to FIG. 4, the switching process to the public network executed by the terminal device 10 will be described. FIG. 4 is a flowchart showing an example of the switching process to the public network according to the first embodiment of the present disclosure. The switching process shown in FIG. 4 is periodically executed by, for example, the terminal device 10 connected to the Private Network.

[0115] As shown in FIG. 4, the terminal device 10 receives a signal from the Private Network (step S101). The terminal device 10 receives a signal from the Private Network via the base station device 20A.

[0116] The terminal device 10 measures the communication quality based on the received signal (step S102). The terminal device 10 measures the communication quality such as, for example, RSRP.

[0117] The terminal device 10 extracts radio parameters from the received signal (step S103). For example, the terminal device 10 extracts radio parameters related to the communication quality from the control information received by PDCCH, MAC CE, RRC, and NAS.

[0118] The terminal device 10 estimates the predicted QoS based on the measured communication quality and the extracted radio parameters (step S104). For example, the terminal device 10 estimates the QoS after a predetermined period from the current time as the predicted QoS based on the communication quality and the radio parameters.

[0119] Subsequently, the terminal device 10 determines whether the predicted QoS can meet the desired QoS (step S105). If the desired QoS can be met for a predetermined period (step S105; No), the process ends.

[0120] On the other hand, if the desired QoS cannot be met (step S105; Yes), the terminal device 10 performs a cell search and estimates the communication quality of the target switching network (step S106). The terminal device 10 performs a cell search for the Roaming destination Network and estimates the communication quality of the target switching network from radio parameters and the like that can be obtained from the received notification information (for example, SIB1).

[0121] Based on the estimated communication quality, the terminal device 10 determines whether to switch to the Roaming destination Network (step S107). For example, the terminal device 10 determines to switch to the Roaming destination Network when the estimated communication quality (QoS) meets a predetermined condition. The predetermined condition includes, for example, at least one of satisfying the desired QoS and improving the communication quality by switching to the Roaming destination Network.

[0122] If it does not switch to the Roaming destination Network (step S107; No), the process ends. On the other hand, if it switches to the Roaming destination Network (step S107; Yes), the terminal device 10 switches the connection destination to the Roaming destination Network (public network) (step S108) and ends the process.

[0123] If there are multiple Roaming destination Networks, the terminal device 10 repeatedly executes steps S106 and S107 and switches to, for example, the Network (public network) with the highest communication quality. Alternatively, the terminal device 10 may switch to a Network (public network) with Roaming experience among the multiple Networks.

[0124] <2.2.2. Switching Process to the Private Network> Next, with reference to FIG. 5, the switching process to the Private Network executed by the terminal device 10 will be described. FIG. 5 is a flowchart showing an example of the switching process to the Private Network according to the first embodiment of the present disclosure. The switching process shown in FIG. 5 is periodically executed by, for example, the terminal device 10 connected to the public network (the network at the roaming destination).

[0125] As shown in FIG. 5, the terminal device 10 receives a signal from the roaming destination (step S201). The terminal device 10 receives a signal from the public network via the base station device 20B.

[0126] The terminal device 10 measures the communication quality based on the received signal (step S202). The terminal device 10 measures the communication quality such as, for example, RSRP.

[0127] The terminal device 10 extracts radio parameters from the received signal (step S203). For example, the terminal device 10 extracts radio parameters related to the communication quality from the control information received by PDCCH, MAC CE, RRC, and NAS.

[0128] The terminal device 10 estimates the predicted QoS based on the measured communication quality and the extracted radio parameters (step S204). For example, the terminal device 10 estimates the predicted QoS based on the communication quality and the radio parameters.

[0129] Subsequently, the terminal device 10 performs cell search and estimates the communication quality of the Private Network (step S205). The terminal device 10 performs cell search for the Private Network and estimates the communication quality (QoS) of the Private Network from radio parameters and the like that can be obtained from the received notification information (for example, SIB1).

[0130] The terminal device 10 determines whether to switch the Network based on the estimated communication quality (step S206). For example, when a predetermined condition is satisfied, the terminal device 10 determines to switch from the Roaming destination to the Private Network. The predetermined condition includes at least one of, for example, satisfying the desired QoS and improving the communication quality by switching to the Private Network.

[0131] If it does not switch to the Private Network (step S206; No), the process ends. On the other hand, if it switches to the Private Network (step S206; Yes), the terminal device 10 switches the connection destination to the Private Network (step S207) and ends the process.

[0132] <<3. Second Embodiment>> In the first embodiment described above, the case where the terminal device 10 communicates using SSSS or DSSS has been described, but it is not limited to this. For example, when the terminal device 10 can attach to a plurality of Networks such as DSDS (Dual SIM Dual Standby), DSDV (Dual SIM Dual VoLTE), or DSDA (Dual SIM Dual Active), it can similarly switch to the Roaming destination. Such a case will be described as the second embodiment.

[0133] <3.1. Configuration Example of Terminal Device> FIG. 6 is a block diagram showing a configuration example of the terminal device 10A according to the second embodiment of the present disclosure. The terminal device 10A shown in FIG. 6 has the same configuration as the terminal device 10 shown in FIG. 3 except for the control unit 130A. The control unit 130A has a communication control unit 132A, a communication quality measurement unit 133A, a radio parameter collection unit 134A, a communication quality prediction unit 135A, and an NW switching determination unit 137A, and has the same configuration as the control unit 130 of the terminal device 10 shown in FIG. 3 except that it does not have the NW search unit 136.

[0134] As described above, the terminal device 10A can attach to a plurality of Networks (for example, a Private Network and a public network) simultaneously. Therefore, the terminal device 10A according to the present embodiment determines whether to switch the connection destination among the plurality of attached Networks. For this reason, in the terminal device 10A according to the present embodiment, the NW search unit 136 is omitted.

[0135] (Communication control unit 132A) The communication control unit 132A in FIG. 6 connects to a plurality of Networks (for example, a Private Network and a public network) via the communication unit 110. For example, in the case of DSDS, the communication control unit 132A connects to both the Private Network and the public network in a standby state and receives control signals from the base station devices 20A and 20B (see FIG. 1). Also, when performing data communication, the communication control unit 132A communicates via either the first wireless communication unit 111 or the second wireless communication unit 112.

[0136] That is, the communication control unit 132A receives information regarding the frequency of the Network (frequency band and bandwidth), notification information (for example, SIB), and signaling of RRC and NAS from each of the Private Network and the public network. The communication control unit 132A acquires cell information from, for example, SIB and signaling of RRC and NAS.

[0137] In this way, the communication control unit 132A receives signals for transitioning from the standby state to the active state from each of the Private Network and the public network. The communication control unit 132A notifies the communication quality measurement unit 133A of information regarding the communication quality based on the received signals. Also, the communication control unit 132A notifies the radio parameter collection unit 134A of information regarding radio parameters based on the received signals.

[0138] (Communication quality measurement unit 133A) The communication quality measurement unit 133A measures the communication quality with each of a plurality of networks based on the information regarding the communication quality acquired from the communication control unit 132A. Note that the communication quality measured by the communication quality measurement unit 133A is the same as the communication quality measured by the communication quality measurement unit 133 shown in FIG. 3.

[0139] The communication quality measurement unit 133A outputs the communication quality with each of the plurality of measured networks to the communication quality prediction unit 135A.

[0140] (Wireless parameter collection unit 134A) The wireless parameter collection unit 134A collects parameter information in the wireless communication with each of the plurality of networks performed by the communication unit 110 via the communication control unit 132A. Note that the wireless parameters collected by the wireless parameter collection unit 134A are the same as the wireless parameters collected by the wireless parameter collection unit 134 shown in FIG. 3.

[0141] The wireless parameter collection unit 134A outputs the wireless parameters of the plurality of collected networks to the communication quality prediction unit 135A.

[0142] (Communication quality prediction unit 135A) The communication quality prediction unit 135A predicts the QoS (predicted QoS) after a predetermined period from the current time for each of the plurality of networks, using the communication quality measured by the communication quality measurement unit 133A and the wireless parameters collected by the wireless parameter collection unit 134A. Note that the predicted QoS estimated by the communication quality prediction unit 135A is the same as the predicted QoS estimated by the communication quality prediction unit 135 shown in FIG. 3.

[0143] In addition, when the terminal device 10 is connected to and communicating with the network (hereinafter also referred to as the priority NW, for example, the Private Network) to which it preferentially connects, the communication quality prediction unit 135A determines whether the communication by the communication unit 110 satisfies the desired QoS after a predetermined period. Note that such determination is the same as the determination by the communication quality prediction unit 135 shown in FIG. 3.

[0144] The communication quality prediction unit 135A notifies the NW switching determination unit 137A of the determination result.

[0145] (NW switching determination unit 137A) The NW switching determination unit 137A determines whether to switch the Network of the communication destination.

[0146] For example, when the communication unit 110 is connected to a priority NW (for example, a Private Network) and communicating, assume that the communication quality prediction unit 135A determines that the predicted QoS cannot meet the desired QoS. In this case, the NW switching determination unit 137A determines whether to switch the communication destination (the connection destination for data communication) from the priority NW to a non-priority NW (for example, a public network).

[0147] The NW switching determination unit 137A determines whether to switch the communication destination from the priority NW to a non-priority NW (for example, a public network) based on the predicted QoS of the non-priority NW by the communication quality prediction unit 135A. When the predicted QoS of the non-priority NW meets the desired QoS, the NW switching determination unit 137A determines to switch the communication destination. Alternatively, when it is estimated that the QoS will be improved by switching to the non-priority NW, the NW switching determination unit 137A determines to switch the communication destination. For example, when the predicted QoS of the non-priority NW is better than the predicted QoS of the priority NW, the NW switching determination unit 137A determines to switch the communication destination.

[0148] When the communication unit 110 is connected to a non-priority NW (for example, a public network) and communicating, the NW switching determination unit 137A determines whether to return the communication destination to the priority NW (for example, a Private Network) based on the QoS of the priority NW, similar to the NW switching determination unit 137 in FIG. 3.

[0149] <3.2. Switching Process> Next, with reference to FIG. 7, the switching process to the non-preferred NW executed by the terminal device 10 will be described. FIG. 7 is a flowchart showing an example of the switching process to the non-preferred NW according to the second embodiment of the present disclosure. The switching process shown in FIG. 7 is periodically executed by, for example, the terminal device 10 that is communicating with the preferred NW.

[0150] As shown in FIG. 7, the terminal device 10 receives signals from each NW (preferred NW and non-preferred NW) (step S301). The terminal device 10 receives signals from the Private Network via the base station device 20A and receives signals from the public network via the base station device 20B.

[0151] Based on the received signals, the terminal device 10 measures the communication quality of each NW (step S302). The terminal device 10 measures the communication quality such as, for example, RSRP.

[0152] The terminal device 10 extracts the radio parameters of each NW from the received signals (step S303). For example, the terminal device 10 extracts the radio parameters related to the communication quality from the control information received by PDCCH, MAC CE, RRC, and NAS.

[0153] Based on the measured communication quality of each NW and the extracted radio parameters of each NW, the terminal device 10 estimates the predicted QoS of each NW (step S304). For example, the terminal device 10 estimates the predicted QoS of each NW based on the communication quality and radio parameters of each NW.

[0154] Subsequently, the terminal device 10 determines whether the predicted QoS of the preferred NW can satisfy the desired QoS (step S305). If it is determined that the desired QoS can be satisfied (step S305; No), the process ends.

[0155] On the other hand, when the desired QoS cannot be satisfied (step S305; Yes), the terminal device 10 determines whether to switch the communication destination based on the predicted QoS of the non-priority NW (step S306). For example, when it is estimated that the predicted QoS of the non-priority NW satisfies the desired QoS, or when the communication quality is improved by switching to the non-priority NW, the terminal device 10 determines to switch the communication destination to the non-priority NW.

[0156] When the communication destination is not switched (step S306; No), the process ends. On the other hand, when the communication destination is switched (step S306; Yes), the terminal device 10 switches the communication destination to the non-priority NW (public network) (step S307) and ends the process.

[0157] Note that when there are multiple non-priority NWs, the terminal device 10 repeatedly executes step S306 and switches to, for example, the non-priority NW with the highest communication quality. Alternatively, the terminal device 10 may switch to the non-priority NW that has communicated most recently among the multiple non-priority NWs.

[0158] Note that the switching process of switching the communication destination from the non-priority NW to the priority NW is the same as the switching process shown in FIG. 5, and thus the description is omitted.

[0159] As described above, the terminal device 10A according to the second embodiment can switch the communication destination from the non-priority NW to the priority NW according to the predicted QoS of the non-priority NW and the priority NW, so that the terminal device 10 can switch the connection destination from the non-priority NW to the priority NW before the actual QoS fails to satisfy the desired QoS. Thereby, the terminal device 10 can continuously perform communication that satisfies the desired QoS.

[0160] In addition, since the terminal device 10A according to the second embodiment can attach to both the non-priority NW and the priority NW, it can determine the switch from the non-priority NW to the priority NW without performing cell search.

[0161] Here, the priority NW is set as the Private Network and the non-priority NW is set as the public network, but it is not limited to this. For example, the non-priority NW may be another Private Network that uses a licensed band.

[0162] Also, here, it is assumed that the terminal device 10A switches the communication destination between the priority NW and the non-priority NW, but it is not limited to this. For example, the terminal device 10A may switch the Network to which it preferentially connects as the connection destination among a plurality of Networks.

[0163] For example, when the terminal device 10A connects to and communicates with the first and second Private Networks that use a licensed band, it is assumed that communication is performed with the first Private Network as the priority NW and the second Private Network as the non-priority NW.

[0164] In this case, in the above-described second embodiment, it is assumed that the terminal device 10A switches the communication destination from the first Private Network, which is the priority NW, to the second Private Network, which is the non-priority NW, according to the predicted QoS of the first Private Network. For example, the terminal device 10A may switch the priority NW from the first Private Network to the second Private Network according to the predicted QoS of the first Private Network. Note that the method of switching the priority NW from the second Private Network to the first Private Network is the same as the method of switching from the first Private Network to the second Private Network.

[0165] <<4. Variations>> In each of the above-described embodiments, when the terminal devices 10 and 10A perform data communication, it is assumed that they switch to and communicate via one of a plurality of Networks (for example, a Private Network or a public network), but the present invention is not limited thereto. For example, the terminal devices 10 and 10A may perform data communication with a plurality of Networks simultaneously.

[0166] In this case, the Private Network accommodates traffic for identifying the terminal device 10. Also, for example, user data such as video data may be transmitted via either the Private Network or the public network based on the predicted QoS. More specifically, for example, an application server that exchanges user data with the terminal device 10 is connected to the Internet, and the terminal device 10 exchanges user data with the application server via the public network. On the other hand, user information (or customer information) necessary for communicating with the application server may be managed within the Private Network, and the terminal device 10 may exchange the user information with the Private Network.

[0167] Alternatively, when the terminal device 10 performs data communication with a plurality of Networks simultaneously, the user data for communication based on the predicted QoS in the plurality of Networks may be divided, and the user data may be transmitted to each of the plurality of Networks. Specifically, the terminal device 10 divides the user data into, for example, 60% and 40% according to the predicted QoS of each of the Private Network and the public network. The terminal device 10 transmits, for example, 60% of the divided user data via the Private Network and 40% of the divided user data via the public network.

[0168] Here, although it is assumed that the plurality of Networks capable of simultaneously performing data communication are a Private Network and a public network, it is not limited thereto. For example, as described above, the plurality of Networks may be a plurality of Private Networks (for example, the first and second Private Networks) using license bands.

[0169] Also, in each of the above-described embodiments, it is assumed that the terminal devices 10 and 10A measure communication quality from the received signal or collect radio parameters, but it is not limited thereto. For example, the terminal devices 10 and 10A may acquire information used for predicting QoS calculation from the Network. Such information includes, for example, the number of terminal devices 10 accommodated in the base station device 20, information such as downlink or uplink traffic volume, and delay time.

[0170] Also, in the above-described second embodiment, it is assumed that the terminal device 10A acquires cell information from signaling such as RRC and NAS via the base station device 20, but it is not limited thereto. The terminal device 10A may acquire information such as information regarding CA availability and information on the application of DSS (Dynamic spectrum sharing) as band information from signaling such as RRC and NAS. Further, when the terminal device 10A is connected to the Network with 4G, the terminal device 10A may acquire information indicating whether 5G can be used in NAS from signaling such as RRC and NAS. Note that this information may be included in signaling such as RRC and NAS by the terminal device 10A, or may be notified separately from this signaling by the Network.

[0171] <<5. Conclusion>> As described above, each embodiment of the present disclosure has been described. However, the technical scope of the present disclosure is not limited to the above-described embodiments as they are, and various modifications are possible without departing from the gist of the present disclosure. Also, components according to different embodiments and modifications may be appropriately combined.

[0172] The control device that controls the terminal devices 10 and 10A of the present embodiment may be realized by a dedicated computer system or by a general-purpose computer system.

[0173] For example, a communication program for executing the above-described operations is stored and distributed in a computer-readable recording medium such as an optical disk, a semiconductor memory, a magnetic tape, or a flexible disk. Then, for example, the program is installed in a computer, and the control device is configured by executing the above-described processing. At this time, the control device may be an external device (for example, a personal computer) of the communication devices 100, 100A to 100C and the terminal devices 200, 200B. Further, the control device may be an internal device (for example, the control units 130, 130A) of the terminal devices 10, 10A.

[0174] Further, the above communication program may be stored in a disk device provided in a server device on a network such as the Internet so that it can be downloaded to a computer. Also, the above-described functions may be realized by the cooperation of an OS (Operating System) and application software. In this case, the part other than the OS may be stored in a medium and distributed, or the part other than the OS may be stored in a server device so that it can be downloaded to a computer.

[0175] Also, among the respective processes described in the above embodiment, all or part of the processes described as being automatically performed can be manually performed, or all or part of the processes described as being manually performed can be automatically performed by a known method. In addition, regarding the processing procedures, specific names, and information including various data and parameters shown in the above document and drawings, they can be arbitrarily changed unless otherwise specified. For example, the various information shown in each figure is not limited to the illustrated information.

[0176] Furthermore, each component of each illustrated device is functionally conceptual and does not necessarily have to be physically configured as shown in the figures. That is, the specific form of the distribution and integration of each device is not limited to that shown in the figures, and all or part of it can be functionally or physically distributed and integrated in any unit according to various loads, usage situations, etc. Note that the configuration by this distribution and integration may be performed dynamically.

[0177] In addition, the above-described embodiments can be appropriately combined in a region where the processing contents do not conflict. Also, the order of each step shown in the flowchart of the above-described embodiments can be appropriately changed.

[0178] For example, this embodiment can also be implemented as any configuration constituting the device or system, such as a processor as a system LSI (Large Scale Integration) or the like, a module using a plurality of processors or the like, a unit using a plurality of modules or the like, a set with other functions added to the unit (i.e., a part of the configuration of the device).

[0179] In this embodiment, the system means a collection of a plurality of components (devices, modules (parts), etc.), and it does not matter whether all the components are in the same housing. Therefore, a plurality of devices housed in separate housings and connected via a network, and a single device in which a plurality of modules are housed in one housing are both systems.

[0180] For example, this embodiment can take a cloud computing configuration in which one function is shared and jointly processed by a plurality of devices via a network.

[0181] Note that the effects in each embodiment described in this specification are merely examples and are not limiting, and there may be other effects.

[0182] Note that this technology can also adopt the following configurations. (1) A first wireless communication unit that connects to and communicates with a first communication network that permits connection in a predetermined area; A second wireless communication unit that connects to and communicates with a second communication network different from the first communication network; A control unit that predicts the communication quality of communication by the first wireless communication unit and determines whether to perform communication by the second wireless communication unit based on whether the predicted communication quality satisfies a desired communication quality; A wireless communication device comprising the above. (2) The wireless communication device according to (1), wherein the control unit determines whether to switch communication by the first wireless communication unit to communication by the second wireless communication unit according to whether the communication quality of communication by the second wireless communication unit satisfies a predetermined condition when the first wireless communication unit is performing communication. (3) The wireless communication device according to (2), wherein the control unit calculates the communication quality of communication by the second wireless communication unit based on at least one of a cell search result and notification information by the second wireless communication unit. (4) The wireless communication device according to (2), wherein the control unit calculates the communication quality of communication by the second wireless communication unit based on control information received by the second wireless communication unit. (5) The wireless communication device according to any one of (1) to (4), wherein the control unit determines whether to switch communication by the second wireless communication unit to communication by the first wireless communication unit according to whether the communication quality of communication by the first wireless communication unit satisfies a predetermined condition when the second wireless communication unit is performing communication. (6) The wireless communication device according to (1), wherein when the control unit determines to perform communication by the second wireless communication unit, it transmits some of the transmission data via the second wireless communication unit and transmits the remaining transmission data via the first wireless communication unit. (7) The second communication network is a public network, the wireless communication device according to any one of (1) to (6). (8) The second communication network is a network that permits connection in an area that is the same as or different from the predetermined area, the wireless communication device according to any one of (1) to (6). (9) Connecting to and communicating with a first communication network that permits connection in a predetermined area; Connecting to and communicating with a second communication network that is different from the first communication network; Predicting the communication quality of the communication connected to the first communication network, and determining whether to perform communication connected to the second communication network based on whether the predicted communication quality satisfies a desired communication quality; A communication method including the above.

Explanation of Signs

[0183] 1 Communication system 10, 10A Terminal device 20A, 20B Base station device 110 Communication unit 111 First wireless communication unit 112 Second wireless communication unit 120 Storage unit 130, 130A Control unit 131 Traffic management unit 132, 132A Communication control unit 133, 133A Communication quality measurement unit 134, 134A Wireless parameter collection unit 135, 135A Communication quality prediction unit 136 NW search unit 137, 137A NW switching determination unit

Claims

1. A first wireless communication unit that connects to and communicates with a private cellular communication network that permits connection in a predetermined area; A second wireless communication unit that connects to and communicates with a cellular communication network different from the private cellular communication network; When communication is being performed by the first wireless communication unit, predicts a first communication quality of the communication by the first wireless communication unit, and determines whether to perform communication by the second wireless communication unit based on whether the predicted first communication quality satisfies a desired communication quality; When communication is being performed by the second wireless communication unit, predicts a second communication quality of the communication by the first wireless communication unit, and determines whether to perform communication by the first wireless communication unit based on whether the second communication quality satisfies a desired communication quality regardless of the communication quality of the communication by the second wireless communication unit, a control unit; A wireless communication device comprising the above.

2. The control unit determines whether to switch the communication by the first wireless communication unit to the communication by the second wireless communication unit according to whether the communication quality of the communication by the second wireless communication unit satisfies a predetermined condition when the communication by the first wireless communication unit is being performed. The wireless communication device according to Claim 1.

3. The control unit calculates the communication quality of the communication by the second wireless communication unit based on at least one of a cell search result and notification information by the second wireless communication unit. The wireless communication device according to Claim 2.

4. The control unit calculates the communication quality of the communication by the second wireless communication unit based on control information received by the second wireless communication unit. The wireless communication device according to Claim 2.

5. When the communication by the first wireless communication unit is being performed, the control unit performs a cell search by the second wireless communication unit according to the predicted first communication quality. The wireless communication device according to Claim 1.

6. When the communication by the second wireless communication unit is being performed, the control unit periodically performs a cell search by the first wireless communication unit. The wireless communication device according to Claim 1.

7. When determining that the communication is to be performed by the second wireless communication unit, the control unit transmits, via the first wireless communication unit, first transmission data at a first ratio corresponding to predicted communication quality predicted in the communication by each of the first wireless communication unit and the second wireless communication unit, and transmits second transmission data at a second ratio corresponding to the predicted communication quality via the second wireless communication unit. The wireless communication device according to claim 1.

8. Connecting to and communicating with a private cellular communication network that permits connection in a predetermined area; Connecting to and communicating with a cellular communication network different from the private cellular communication network; When communicating while connected to the private cellular communication network, predicting a first communication quality of the communication connected to the private cellular communication network, and determining whether to perform the communication connected to the cellular communication network based on whether the predicted first communication quality satisfies a desired communication quality; When communicating while connected to the cellular communication network, predicting a second communication quality of the communication connected to the private cellular communication network, and determining whether to perform the communication connected to the private cellular communication network based on whether the second communication quality satisfies a desired communication quality regardless of the communication quality of the communication connected to the cellular communication network; A communication method comprising the above.

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