Patent Publication Number: US-2022232364-A1

Title: Wireless communication device and communication control method

Description:
FIELD 
     The present disclosure relates to a wireless communication device and a communication control method. 
     BACKGROUND 
     In recent years, a technology has been proposed which connects one user equipment (UE) to networks of a plurality of communication carriers by mounting a plurality of subscriber identity modules (SIMs) in the UE. In such a technology, when the UE includes only one transmission/reception unit, the UE cannot be simultaneously connected to networks of different communication carriers. For example, even in a case where the UE is mounted with two SIMs and can be connected to two networks, when the UE includes only one transmission/reception unit, while being connected to one network, the UE cannot receive paging from another network. 
     In this regard, a technology has been proposed in which a UE is simultaneously connected to a plurality of networks by sharing information with the plurality of networks (see, for example, Patent Literature 1). In such a technology, when paging information from another network is provided to one network, the UE can receive paging from the another network which is not directly connected via the one network. 
     CITATION LIST 
     Patent Literature 
     Patent Literature 1: US 2013/0303203 A 
     SUMMARY 
     Technical Problem 
     However, in the above related art, it is disclosed that the networks share the paging information, but it cannot be said that a specific mechanism of how the UE is connected to a plurality of networks has been sufficiently studied. 
     In this regard, the present disclosure proposes a mechanism in which a UE mounted with a plurality of SIMs can be connected to a plurality of networks. 
     Solution to Problem 
     The wireless communication device according to the present disclosure includes a control unit. The control unit acquires a first PLMN list on the basis of information stored in a first subscriber identity module, selects a home PLMN from the first PLMN list, acquires a second PLMN ID on the basis of information stored in a second subscriber identity module, performs a first registration request to a first management device which belongs to the home PLMN and manages registration of the wireless communication device in a case where the second PLMN ID is not included in the first PLMN list, and performs, to the first management device, a second registration request with information regarding the second PLMN included therein in a case where the second PLMN ID is included in the first PLMN list. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG. 1  is a diagram illustrating an example of a communication system according to an embodiment of the present disclosure. 
         FIG. 2  is a diagram (1) illustrating an example of a registration process according to the embodiment of the present disclosure. 
         FIG. 3  is a diagram (2) illustrating an example of a registration process according to the embodiment of the present disclosure. 
         FIG. 4  is a diagram illustrating an example of a network architecture configuration according to the embodiment of the present disclosure. 
         FIG. 5  is a diagram illustrating a configuration example of a management device according to the embodiment of the present disclosure. 
         FIG. 6  is a state transition diagram illustrating a registration state of a UE. 
         FIG. 7  is a diagram illustrating a configuration example of a wireless communication device according to the embodiment of the present disclosure. 
         FIG. 8  is a diagram for explaining an example of a state transition of the UE. 
         FIG. 9  is a flowchart (1) illustrating an example of a registration activation process according to the embodiment of the present disclosure. 
         FIG. 10  is a flowchart (2) illustrating an example of the registration activation process according to the embodiment of the present disclosure. 
         FIG. 11  is a flowchart (3) illustrating an example of the registration activation process according to the embodiment of the present disclosure. 
         FIG. 12  is a flowchart (4) illustrating an example of the registration activation process according to the embodiment of the present disclosure. 
         FIG. 13  is a flowchart illustrating an example of a registration selection process according to the embodiment of the present disclosure. 
         FIG. 14  is a sequence diagram for explaining the registration selection process. 
         FIG. 15  is a sequence diagram for explaining an example of a first registration process. 
         FIG. 16  is a sequence diagram for explaining an example of a second registration process. 
         FIG. 17  is a sequence diagram for explaining another example of the second registration process. 
         FIG. 18  is a sequence diagram for explaining an example of a third registration process. 
         FIG. 19  is a flowchart for explaining a selection process of a switching instruction. 
         FIG. 20  is a diagram illustrating an example of a network architecture configuration of LTE. 
         FIG. 21  is a diagram illustrating an example of a state transition of an EMM. 
         FIG. 22  is a diagram illustrating an example of a state transition of an ECM. 
         FIG. 23  is a diagram illustrating an example of a state transition of an RRC. 
         FIG. 24  is a diagram illustrating an example of the state transition of the EMM in the wireless communication device. 
         FIG. 25  is a diagram illustrating an example of the state transition of the ECM in the wireless communication device. 
         FIG. 26  is a diagram illustrating an example of the state transition of the RRC in the wireless communication device. 
         FIG. 27  is a diagram illustrating an example of the registration process in LTE. 
         FIG. 28  is a diagram illustrating an example of the registration process in a case where LTE and NR are mixed. 
         FIG. 29  is a block diagram illustrating an example of a schematic configuration of a smartphone to which a technology according to the present disclosure can be applied. 
         FIG. 30  is a block diagram illustrating an example of a schematic configuration of a car navigation device to which the technology according to the present disclosure can be applied. 
     
    
    
     DESCRIPTION OF EMBODIMENTS 
     Hereinafter, each of the embodiments of the present disclosure will be described in detail on the basis of the drawings. Incidentally, in each of the following embodiments, the same reference signs are given to the same portions, and duplicate description will be omitted. 
     Further, in this specification and the drawings, a plurality of components having substantially the same functional configuration may be distinguished by adding different alphabets after the same reference signs. However, in a case where it is not necessary to distinguish each of the plurality of components having substantially the same functional configuration, only the same reference signs are given. 
     The present disclosure will be described according to the order of items described below. 
     1. Introduction 
     2. Overview of communication system
         2.1. Overview of system configuration   2.2. Overview of registration process       

     3. Configuration of communication system
         3.1. Configuration example of network architecture   3.2. Configuration example of management device   3.3. Configuration example of wireless communication device       

     4. Operation of communication system
         4.1. Registration activation process
           4.1.1. When power is turned on   4.1.2. Switching instruction from upper layer   4.1.3. Switching instruction from management device   
           4.2. Registration selection process   4.3. Details of registration selection process   4.4. Registration process
           4.4.1. First registration process   4.4.2. Second registration process   4.4.3. Third registration process   
           4.5. Selection process of switching instruction       

     5. Application example
         5.1. Application example of radio access technology
           5.1.1. Application example to LTE   5.1.2. Application example in case where LTE and NR are mixed   
           5.2. Application example regarding wireless communication device   5.3. Other application examples       

     6. Modification 
     7. Conclusion 
     1. INTRODUCTION 
     A radio access technology such as long term evolution (LTE) and new radio (NR) is examined in 3rd generation partnership project (3GPP). LTE and NR are a type of cellular communication technology and enable mobile communication of terminal devices (UEs) by arranging a plurality of areas covered by base stations in a cell shape. Incidentally, in the following description, it is assumed that “LTE” includes LTE-advanced (LTE-A), LTE-advanced pro (LTE-A Pro), and evolved universal terrestrial radio access (EUTRA). Further, it is assumed that NR includes new radio access technology (NRAT) and further EUTRA (FEUTRA). 
     NR is a radio access technology (RAT) of a next generation (fifth generation) of LTE. NR is a radio access technology that can support various use cases including enhanced mobile broadband (eMBB), massive machine type communications (mMTC), and ultra-reliable and low latency communications (URLLC). NR is examined for a technical framework that addresses usage scenarios, requirements, and deployment scenarios in those use cases. 
     Further, in NR, an examination on a non-terrestrial network (NTN) has started due to an increase in demand for wide area coverage, connection stability, and the like. In the non-terrestrial network, a wireless network is scheduled to be provided to a terminal device via a base station other than a ground station such as a satellite station or an aircraft station. The base station other than the ground station is referred to as a non-ground station or a non-ground base station. A wireless network provided by a ground station is referred to as a terrestrial network (TN). By using the same wireless access system for the terrestrial network and the non-terrestrial network, integrated operation of the terrestrial network and the non-terrestrial network becomes possible. 
     Incidentally, in the embodiment of the present disclosure, a ground station (also referred to as a ground base station) refers to a base station (including a relay station) installed on the ground. The “ground” is a ground in a broad sense including not only the ground (land) but also underground, water, and underwater, and may be a concept including the inside or the outside of a building or a vehicle on the ground. 
     2. OVERVIEW OF COMMUNICATION SYSTEM 
     &lt;2.1. Overview of System Configuration&gt; 
     An overview of a communication system according to an embodiment of the present disclosure will be described with reference to  FIG. 1 .  FIG. 1  is a diagram illustrating an example of the communication system according to the embodiment of the present disclosure. As illustrated in  FIG. 1 , the communication system includes a UE  1 , first and second subscriber identity modules (hereinafter, also referred to as first and second SIMs  30 A and  30 B) mounted in the UE  1 , first and second networks  20 A and  20 B, and first and second management devices  10 A and  10 B. 
     Incidentally, hereinafter, in order to simplify the description, a case where two SIMs  30  are mounted in the UE  1  (dual SIM) will be described as an example. However, a plurality of SIMs  30  may be mounted in the UE  1 , and three or more SIMs  30  may be mounted. 
     The first and second management devices  10 A and  10 B are network devices which manage a plurality of UEs  1 . For example, the first and second management devices  10 A and  10 B are a device which functions as a mobility management entity (MME) in LTE or an access and mobility management function (AMF) in NR. In this embodiment, it is assumed that the first and second management devices  10 A and  10 B are operated by different first and second mobile network operators (MNO), respectively, but the present invention is not limited thereto. The first MNO and the second MNO may be the same MNO. Incidentally, it is assumed that the first and second management devices  10 A and  10 B communicate with each other via a network N different from the first and second networks  20 A and  20 B, for example. 
     The first network  20 A is a network operated by the first MNO, and the first management device  10 A communicates with the UE  1  via the first network  20 A. The second network  20 B is a network operated by the second MNO, and the second management device  10 B communicates with the UE  1  via the second network  20 B. 
     The first and second networks  20 A and  20 B are, for example, an evolved packet system (EPSS) in LTE and are a 5G System (5GS)/next generation system (NGS) in NR. 
     The first and second MNOs may operate respective networks by using different radio access technologies, or may operate respective networks by using the same radio access technology. For example, the first MNO may provide a wireless service to the UE  1  according to an LTE wireless communication system, and the second MNO may provide a wireless service according to an NR wireless communication system. As described above, the first and second MNOs may not necessarily adopt the same wireless communication system. Alternatively, the first MNO and the second MNO may provide wireless services according to the same NR wireless communication system. 
     The first SIM  30 A stores information for the user using the UE  1  to use the service provided by the first MNO. The first SIM  30 A stores, for example, a list (first PLMN list  40 ) of public land mobile networks (PLMN) to which the UE  1  can be connected. 
     The first PLMN list  40  includes, for example, IDs (PLMN IDs) for identifying a plurality of connectable PLMNs. For example, the first PLMN list  40  includes, in addition to a first PLMN ID held by the first MNO, a PLMN ID held by an MNO with which the first MNO has a roaming agreement. 
     The second SIM  30 B stores information for the user using the UE  1  to use the service provided by the second MNO. The second SIM  30 B stores, for example, an ID (PLMN ID) for identifying a PLMN to which the UE  1  can be connected. Incidentally, although  FIG. 1  illustrates an example in which the second SIM  30 B stores one PLMN ID, the second SIM  30 B may store a plurality of PLMN IDs. In this case, for example, it is assumed that the second SIM  30 B stores the second PLMN list similarly to the first SIM  30 A. 
     The UE  1  is mounted with the first and second SIMs  30 A and  30 B. Further, the UE  1  includes a wireless communication device  100 . The wireless communication device  100  is alternatively connected to one of the first network  20 A and the second network  20 B on the basis of the information stored in the first and second SIMs  30 A and  30 B, and performs communication. 
     As described above, the UE  1  is mounted with the two SIMs  30 . However, the UE  1  cannot be connected to the first and second networks  20 A and  20 B at the same time and communicates with one of the first and second networks  20 A and  20 B. In other words, the UE  1  performs communication with the first and second networks  20 A and  20 B in a time-division manner. 
     &lt;2.2. Overview of Registration Process&gt; 
     Next, an overview of a registration process according to the embodiment of the present disclosure will be described with reference to  FIGS. 2 and 3 .  FIG. 2  is a diagram (1) illustrating an example of the registration process according to the embodiment of the present disclosure.  FIG. 3  is a diagram (2) illustrating an example of the registration process according to the embodiment of the present disclosure. 
     The registration process according to the embodiment of the present disclosure is realized by the wireless communication device  100  of the UE  1 . Incidentally, here, in addition to the registration process by the wireless communication device  100 , a process of the first management device  10 A which receives the registration request by the wireless communication device  100  will also be briefly described. 
     Further, here, it is assumed that the wireless communication device  100  performs a registration request to the first management device  10 A for connection to the first network  20 A, and receives the service provided by the first MNO. 
     Whether or not the UE  1  can receive the service provided by the second MNO via the first network  20 A differs depending on whether or not the first and second MNOs have a roaming agreement, for example. In this regard, first, for example, a case where the first and second MNOs do not have a roaming agreement, and the wireless communication device  100  cannot receive the service provided by the second MNO via the first network  20 A will be described with reference to  FIG. 2 . Subsequently, for example, a case where the first and second MNOs have a roaming agreement, and the wireless communication device  100  can receive the service provided by the second MNO via the first network  20 A will be described with reference to  FIG. 3 . 
     As illustrated in  FIG. 2 , the wireless communication device  100  acquires the first PLMN list  40  from the first SIM  30 A (step S 1 ). The first PLMN list  40  includes, in addition to the first PLMN ID of the first MNO, a PLMN ID of an MNO which has a roaming agreement with the first MNO. As described above, the first PLMN list  40  includes a plurality of PLMN IDs. 
     The wireless communication device  100  selects an HPLMN (home PLMN) from the first PLMN list  40  (step S 2 ). The wireless communication device  100  selects a PLMN ID which is available and has a higher priority as the HPLMN from a plurality of PLMN IDs included in the first PLMN list  40 . 
     Subsequently, the wireless communication device  100  acquires a second PLMN ID from the second SIM  30 B (step S 3 ). In the example of  FIG. 2 , the wireless communication device  100  acquires “PLMN_ 21 ” as the second PLMN ID. Incidentally, here, the wireless communication device  100  acquires the second PLMN ID, but the present invention is not limited thereto. For example, the wireless communication device  100  may acquire the second PLMN list from the second SIM  30 B. Here, the second PLMN list may include a plurality of PLMN IDs in addition to the second PLMN ID, for example. 
     The wireless communication device  100  determines whether or not the second PLMN ID acquired from the second SIM  30 B is included in the first PLMN list  40  (step S 4 ). In the example illustrated in  FIG. 2 , the first and second MNOs do not have a roaming agreement and do not receive the service of the second MNO via the first network  20 A, and thus the first PLMN list  40  does not include the second PLMN ID (PLMN_ 21 ). 
     In this case, the wireless communication device  100  performs (transmits) a first registration request to the first management device  10 A belonging to the HPLMN (step S 5 ). The first registration request herein is an Attach request in LTE and a Registration request in NR. 
     When receiving the first registration request from the wireless communication device  100  and permitting the registration, the first management device  10 A transmits first registration acceptance (Accept) to the wireless communication device  100  (step S 6 ). 
     Accordingly, the wireless communication device  100  is connected to the first network  20 A and enters the communication range (registered state) with respect to the communication performed via the first network  20 A. On the other hand, the wireless communication device  100  is not connected to the second network  20 B, and is out of the communication range for the communication performed via the second network  20 B (deregistered state). 
     Subsequently, a case where the first and second MNOs have a roaming agreement will be described with reference to  FIG. 3 . Incidentally, the processing up to step S 4  is the same as that in  FIG. 2 , and thus the description thereof will be omitted. 
     In a case where the first and second MNOs have a roaming agreement, the first PLMN list  40  includes the second PLMN ID (PLMN_ 21 ) as illustrated in  FIG. 3 . In this case, the wireless communication device  100  performs a second registration request to the first management device  10 A belonging to the HPLMN (step S 7 ). Specifically, the wireless communication device  100  performs (transmits), to the first management device  10 A, the second registration request with information (for example, “PLMN_ 21 ” which is the second PLMN ID) regarding the second PLMN included therein. 
     Upon receiving the second registration request, the first management device  10 A registers the wireless communication device  100 . Further, the first management device  10 A notifies the second management device  10 B belonging to the second PLMN included in the second registration request of the registration of the wireless communication device  100  (step S 8 ). 
     Accordingly, the first management device  10 A can communicate with the UE  1 , and the second management device  10 B can communicate with the UE  1  via the first network  20 A, for example. 
     The first management device  10 A transmits second registration acceptance (Accept) of permitting registration to the UE  1  (step S 9 ). 
     Accordingly, the wireless communication device  100  is connected to the first network  20 A and enters the communication range with respect to communication performed via the first network  20 A. Further, the wireless communication device  100  is connected to the second network  20 B via the first network  20 A, and also enters the communication range with respect to the second network  20 B. 
     Incidentally, in the following embodiment, in order to simplify the description, a case will be described in which an NR technology is used as a radio access technology. A case where LTE is used and a case where LTE and NR are mixed will be collectively described as an application example in  FIG. 20  and subsequent drawings. 
     3. CONFIGURATION OF COMMUNICATION SYSTEM 
     &lt;3.1. Configuration Example of Network Architecture&gt; 
     Next, an overview of a configuration of a network architecture of NR will be described with reference to  FIG. 4 .  FIG. 4  is a diagram illustrating an example of the network architecture configuration according to the embodiment of the present disclosure. 
     The network architecture illustrated in  FIG. 4  includes the UE  1  and the first and second networks  20 A and  20 B. In  FIG. 4 , the UE  1  is connected to the first network  20 A, but the UE  1  is also connectable to the second network  20 B. 
     The control planes of the first and second networks  20 A and  20 B are connected at a reference point N 32  via security edge protection proxies (SEPPs)  1100 A and  1100 B. Further, a user plane is connected via a point of interface (POI)  2000 . 
     The function group of the control planes includes an authentication server function (AUSF)  1210 , a network exposure function (NEF)  1220 , a network repository function (NRF)  1230 , a network slice selection function (NSSF)  1240 , a policy control function (PCF)  1250 , a session management function (SMF)  1260 , a unified data management (UDM)  1270 , an application function (AF)  1280 , and an AMF  1290 . The UDM  1270  includes a unified data repository (UDR) which holds and manages subscriber information and a front end (FE) unit which processes the subscriber information. Further, the AMF  1290  performs mobility management, and the SMF  1260  performs session management. A device which realizes the function of the AMF  1290  is the management device  10  in  FIG. 1 . 
     A user plane function (UPF)  3100  has a function of user plane processing. The management device  10  may have a function as the UPF  3100 . A (R)AN  3200  has a function of enabling connection to a radio access network (RAN) and connection to an access network (AN) other than the RAN. The (R)AN  3200  includes a base station device called a gNB or an ng-eNB. A data network (DN)  3300  has a function of enabling connection to MNO-specific services, the Internet, and third-party services. 
     &lt;3.2. Configuration Example of Management Device&gt; 
     Subsequently, a configuration of the management device  10  according to the embodiment of the present disclosure will be described with reference to  FIG. 5 .  FIG. 5  is a diagram illustrating a configuration example of the management device  10  according to the embodiment of the present disclosure. 
     The management device  10  includes a network communication unit  11 , a storage unit  12 , and a control unit  13 , and realizes the function of the AMF  1290  (see  FIG. 4 ). Incidentally, the configuration illustrated in  FIG. 5  is a functional configuration, and the hardware configuration may be different therefrom. Further, the functions of the management device  10  may be distributed and implemented in a plurality of physically separated configurations. For example, the management device  10  may be configured by a plurality of server devices. 
     The network communication unit  11  is a communication interface for communication with other devices. The network communication unit  11  may be a network interface or a device connection interface. The network communication unit  11  has a function of directly or indirectly connecting to a core network. For example, the network communication unit  11  may include a local area network (LAN) interface such as a network interface card (NIC), or may include a universal serial bus (USB) interface configured by a USB host controller, a USB port, and the like. Further, the network communication unit  11  may be a wired interface or a wireless interface. The network communication unit  11  functions as a communication means of the management device  10 . The network communication unit  11  communicates with the UE  1 , another management device, or a communication function network function (NF) according to the control of the control unit  13 . In a 5G architecture, a service-based architecture is adopted, and the NFs are connected via a uniform interface called a service-based interface. 
     The storage unit  12  is a storage device, such as a dynamic random access memory (DRAM), a static random access memory (SRAM), a flash memory, and a hard disk, which can read and write data. The storage unit  12  functions as a storage means of the management device  10 . The storage unit  12  stores, for example, a state of registration management (RM) of the UE  1 . The storage unit  12  may function as a home memory which stores the position information of the UE  1 . 
     The control unit  13  is a controller which controls each unit of the management device  10 . For example, the control unit  13  is realized by a processor such as a central processing unit (CPU) or a micro processing unit (MPU). For example, the control unit  13  is realized when the processor executes various programs stored in the storage device inside the management device  10  by using random access memory (RAM) or the like as a work area. Incidentally, the control unit  13  may be realized by an integrated circuit such as an application specific integrated circuit (ASIC) and a field programmable gate array (FPGA). Any one of the CPU, MPU, ASIC, and FPGA can be regarded as a controller. 
     As illustrated in  FIG. 5 , the control unit  13  includes a state management unit  131 , a first transmission/reception unit  132 , and a second transmission/reception unit  133 , and realizes or executes a function and an action of communication processing such as a selection process of a switching instruction described below. Incidentally, the internal structure of the control unit  13  is not limited to the configuration illustrated in  FIG. 5 , and may be another configuration as long as communication processing to be described later is performed. Further, the connection relationship among the processing units included in the control unit  13  is not limited to the connection relationship illustrated in  FIG. 5 , and may be another connection relationship. 
     The state management unit  131  manages the state transition of the RM of the UE  1 . Here, the state transition of the RM of the UE  1  will be described with reference to  FIG. 6 .  FIG. 6  is a state transition diagram illustrating the registration state of the UE  1 . 
     In  FIG. 6 , RM-REGISTERED indicates a state in which the UE  1  (or the wireless communication device  100 ) is registered, and RM-DEREGISTERED indicates a state in which the UE  1  is not registered (non-registration). That is, the state transition of the RM of the UE  1  depends on whether the UE  1  is registered in 5G core ( 5  GC)/next generation core (NGC). 
     When the power of the UE  1  is turned on and registered in the management device  10 , the state management unit  131  transitions the state of the UE  1  from RM-DEREGISTERED to RM-REGISTERED. 
     When the power of the UE  1  is turned off, or the UE  1  is out of the range, the management device  10  deletes the registration of the UE  1 , and the state management unit  131  transitions the state of the UE  1  from RM-REGISTERED to RM-DEREGISTERED. 
     Alternatively, in a case where the management device  10  receives the Registration request from the UE  1  (or a case where the management device  10  transmits a Registration Accept to the UE  1 ), the state management unit  131  transitions the state of the UE  1  from RM-DEREGISTERED to RM-REGISTERED. Further, in a case where the management device  10  receives a Deregistration request from the UE  1  (or a case where the management device  10  transmits a Deregistration Accept to the UE  1 ), the state management unit  131  transitions the state of the UE  1  from RM-REGISTERED to RM-DEREGISTERED. 
     Incidentally, for example, the state management unit  131  may manage the first PLMN ID stored in the first SIM  30 A as a home PLMN, and manage the second PLMN ID stored in the second SIM  30 B as a visitor PLMN. 
     The first transmission/reception unit  132  transmits and receives signals to and from another management device  10 . In a case where the second PLMN is included in the second registration request, the first transmission/reception unit  132  notifies the second management device  10 B belonging to the second PLMN of the registration of the UE  1 . Further, in a case where the second PLMN is managed as the visitor PLMN, the first transmission/reception unit  132  receives the notification regarding paging from the second management device  10 B to the UE  1 . Such notification may include, for example, information regarding the size (hereinafter, also referred to as a paging size) of data to be transmitted by such paging. 
     The second transmission/reception unit  133  transmits and receives signals to and from the UE  1 . The second transmission/reception unit  133  receives a Registration request and a Deregistration request from the UE  1 . Further, in the case of accepting the Registration request, the first transmission/reception unit  132  transmits a Registration accept to the UE  1 . 
     The second transmission/reception unit  133  transmits, to the UE  1 , a switching instruction for switching the PLMN to be connected, for example. For example, in a case where the first transmission/reception unit  132  receives the notification regarding paging from the second management device  10 B to the UE  1 , the second transmission/reception unit  133  transmits the switching instruction. 
     At this time, the second transmission/reception unit  133  transmits the switching instruction according to the size of paging to the UE  1 . For example, in a case where the paging size is larger than a predetermined threshold, the second transmission/reception unit  133  transmits, to the UE  1 , a switching instruction (hereinafter, also referred to as a complete switching instruction) for completely switching the network  20  (the connection destination of the UE  1 ). On the other hand, in a case where the paging size is equal to or smaller than the predetermined threshold, the second transmission/reception unit  133  transmits, to the UE  1 , a switching instruction (hereinafter, also referred to as a temporary switching instruction) for temporarily switching the network  20  (the connection destination of the UE  1 ) during a first timer period T 1 . The temporary switching instruction includes information (for example, a value of the first timer period T 1 ) regarding the first timer period T 1 . 
     &lt;3.3. Configuration Example of Wireless Communication Device&gt; 
       FIG. 7  is a diagram illustrating a configuration example of the wireless communication device  100  according to the embodiment of the present disclosure. As illustrated in  FIG. 7 , the wireless communication device  100  includes an antenna unit  110 , a communication unit  120 , a storage unit  130 , and a control unit  140 . 
     The antenna unit  110  radiates a signal output by the communication unit  120  as a radio wave into space. Further, the antenna unit  110  converts the radio wave in space into a signal, and outputs the signal to the communication unit  120 . 
     The communication unit  120  wirelessly transmits and receives the signal. For example, the communication unit  120  receives a downlink signal from the management device  10  and transmits an uplink signal to the management device  10 . 
     The storage unit  130  is a storage device, such as a dynamic random access memory (DRAM), a static random access memory (SRAM), a flash memory, and a hard disk, which can read and write data. The storage unit  130  functions as a storage means of the wireless communication device  100 . The storage unit  130  temporarily or permanently stores various programs and various data for the operation of the wireless communication device  100 . 
     The control unit  140  is a controller which controls each unit of the wireless communication device  100 . For example, the control unit  140  is realized by a processor such as a central processing unit (CPU) or a micro processing unit (MPU). For example, the control unit  140  is realized when the processor executes various programs stored in the storage device inside the wireless communication device  100  by using random access memory (RAM) or the like as a work area. Incidentally, the control unit  140  may be realized by an integrated circuit such as an application specific integrated circuit (ASIC) and a field programmable gate array (FPGA). Any one of the CPU, MPU, ASIC, and FPGA can be regarded as a controller. 
     As illustrated in  FIG. 7 , the control unit  140  includes a switching control unit  141 , a first acquisition unit  142 , a selection unit  143 , a second acquisition unit  144 , a determination unit  145 , a registration selection unit  146 , a registration processing unit  147 , a deregistration processing unit  148 , and a state management unit  149 . Each unit of the control unit  140  realizes or executes a function and an action of communication processing such as a registration process described below. Incidentally, the internal structure of the control unit  140  is not limited to the configuration illustrated in  FIG. 7 , and may have another configuration as long as the communication processing to be described later is performed. Further, the connection relationship among the processing units included in the control unit  140  is not limited to the connection relationship illustrated in  FIG. 7 , and may be another connection relationship. 
     The switching control unit  141  controls switching of the connection destination network  20  (the connection destination of the UE  1 ) in accordance with an instruction from the management device  10  or an upper layer such as an application layer. The switching control unit  141  controls switching of the connection destination, for example, in a case where the power of the UE  1  or the wireless communication device  100  is turned on or a case where a switching instruction is received from the management device  10 . Alternatively, the switching control unit  141  controls the switching of the connection destination, for example, in a case where a switching instruction is received from the upper layer with the activation of a predetermined application by a user operation as a trigger. 
     For example, when the power of the UE  1  or the wireless communication device  100  is turned on, the switching control unit  141  controls the switching of the network  20  so as to maintain the previous connection destination. That is, the switching control unit  141  determines the connection to the network  20  selected when the power is turned off. 
     On the other hand, in a case where there is an instruction from the management device  10  or the upper layer, the switching control unit  141  switches the connection destination network  20  from the currently connected network to the unconnected network on the basis of the switching instruction. 
     At this time, in a case where the switching instruction is a temporary switching instruction including the first timer period T 1 , the switching control unit  141  performs control to temporarily switch the connection destination to the first network  20 A during a second timer period T 2  according to the first timer period T 1 . 
     Incidentally, a process of selecting a connection destination network by the switching control unit  141  will be described later with reference to  FIGS. 9 to 12 . Further, hereinafter, in order to simplify the description, it is assumed that the switching control unit  141  selects the first network  20 A as the connection destination. 
     According to the switching control of the network  20  (the connection destination of the UE  1 ) by the switching control unit  141 , the first acquisition unit  142  acquires the first PLMN list  40  from the first SIM  30 A corresponding to the first network  20 A to be connected. 
     The selection unit  143  selects the available PLMN with a higher priority as the HPLMN from the first PLMN list  40  acquired by the first acquisition unit  142 . 
     Subsequently, the second acquisition unit  144  acquires the second PLMN ID from the second SIM  30 B corresponding to the second network  20 B. Incidentally, the second acquisition unit  144  may acquire the second PLMN list including a plurality of second PLMN IDs. 
     The determination unit  145  determines whether or not the second PLMN ID acquired by the second acquisition unit  144  is included in the first PLMN list  40  acquired by the first acquisition unit  142 . In a case where the second acquisition unit  144  acquires a plurality of second PLMN IDs, the determination unit  145  determines whether or not all the second PLMN IDs are included in the first PLMN list  40 , for example, according to the priority of the second PLMN list. 
     The registration selection unit  146  selects the registration process to be performed by the registration processing unit  147  on the basis of the determination result. In a case where all the second PLMN IDs are not included in the first PLMN list  40 , the registration selection unit  146  selects a first registration process. On the other hand, in a case where the second PLMN ID is included in the first PLMN list  40 , the registration selection unit  146  selects a second registration process. 
     In a case where the switching control unit  141  selects the first network  20 A of the connection destination to be switched on the basis of the temporary switching instruction from the management device  10 , the registration selection unit  146  selects a third registration process. 
     The registration processing unit  147  executes the registration process according to the selection of the registration selection unit  146 . 
     In a case where the registration selection unit  146  selects the first registration process, the registration processing unit  147  transmits a Registration request to the first management device  10 A belonging to the first network  20 A. 
     The first registration process is executed, for example, in a case where the wireless communication device  100  is not registered in the management device  10 . Alternatively, for example, in a case where the wireless communication device  100  is registered in the second management device  10 B, the first registration process is executed in a case where the registration destination of the wireless communication device  100  is switched from the second management device  10 B to the first management device  10 A. 
     In a case where the registration selection unit  146  selects the second registration process, the registration processing unit  147  transmits a second Registration request including information regarding the second PLMN, such as the second PLMN ID, to the first management device  10 A. 
     The second registration process is a process for requesting the first management device  10 A to manage the first PLMN as a home PLMN and, for example, manage the second PLMN as a visitor PLMN. 
     The second registration process is executed, for example, in a case where the wireless communication device  100  is not registered in the management device  10 . Alternatively, for example, in a case where the wireless communication device  100  is registered in the second management device  10 B, the second registration process is executed in a case where the registration destination of the wireless communication device  100  is switched from the second management device  10 B to the first management device  10 A. 
     In a case where the registration selection unit  146  selects the third registration process, the registration processing unit  147  performs the third registration process. 
     The third registration process is executed, for example, in a case where a temporary switching instruction is received from the second management device  10 B. The third registration process is performed, for example, in a case where the first PLMN is managed as the visitor PLMN by the second management device  10 B, and paging from the first network  20 A occurs. In this case, the second management device  10 B transmits a temporary switching instruction including information regarding the first timer period T 1 . 
     Upon receiving the temporary switching instruction, the switching control unit  141  performs control to temporarily switch the connection destination from the second network  20 B to the first network  20 A during the second timer period T 2  according to the first timer period T 1 . In this regard, as the third registration process, the registration processing unit  147  requests the first management device  10 A to perform registration during the second timer period T 2 . Specifically, the registration processing unit  147  transmits a third Registration request including information regarding the second timer period T 2  to the first management device  10 A. 
     For example, in a case where the connection destination network  20  is switched on the basis of a switching instruction from the upper layer or the network  20 , the deregistration processing unit  148  executes a registration deletion (deregistration) request process on the second network  20 B connected before switching. 
     The state management unit  149  manages the state transition of the RM of the UE  1 . Here, the state transition of the RM of the UE  1  will be described with reference to  FIG. 8 .  FIG. 8  is a diagram for explaining an example of the state transition of the UE  1 . For each PLMN to be connected, the state management unit  149  manages, as the state of the UE  1 , the registration state (RM-REGISTERED) registered in the management device  10  and the non-registration state (RM-DEREGISTERED) not registered. 
     In a case where the UE  1  (or the wireless communication device  100 ) is not registered in either of the first and second management devices  10 A and  10 B, for example, when the power is turned on, the state management unit  149  manages both the first PLMN and the second PLMN as the non-registration state (RM-DEREGISTERED_A, RM-DEREGISTERED_B). 
     Here, it is assumed that the registration processing unit  147  performs the first or second registration process on the first management device  10 A. In this case, the state management unit  149  manages the first PLMN as the registration state (RM-REGISTERED_A) and the second PLMN as the non-registration state (RM-DEREGISTERED_B). 
     On the other hand, in a case where the deregistration processing unit  148  requests the first management device  10 A to delete the registration of the UE  1  in the “RM-REGISTERED_A, RM-DEREGISTERED_B” state, the state management unit  149  manages both the first and second PLMNs as the non-registration state (RM-DEREGISTERED_A, RM-DEREGISTERED_B). 
     It is assumed that the switching control unit  141  selects to perform the registration process on the second management device  10 B with both the first and second PLMNs in the non-registration state (RM-DEREGISTERED_A, RM-DEREGISTERED_B). In this case, the state management unit  149  causes the first PLMN to transition to the non-registration state (RM-DEREGISTERED_A) and the second PLMN to transition to the registration state (RM-REGISTERED_B). 
     It is assumed that the registration deletion of UE  1  is requested to the second management device  10 B in the “RM-DEREGISTERED_A, RM-REGISTERED_B” state. In this case, the state management unit  149  causes both the first and second PLMNs to transition to the non-registration state (RM-DEREGISTERED_A, RM-DEREGISTERED_B). 
     Here, a state transition in a case where the registration processing unit  147  performs the third registration process will be described. The third registration process is executed in a case where the first PLMN is in the registration state (RM-REGISTERED_A), and the second PLMN is in the non-registration state (RM-DEREGISTERED_B). Alternatively, the third registration process is executed in a case where the first PLMN is in the non-registration state (RM-DEREGISTERED_A) and the second PLMN is in the registration state (RM-REGISTERED_B). 
     For example, it is assumed that the third registration process is executed with the first PLMN in the non-registration state (RM-DEREGISTERED_A) and the second PLMN in the registration state (RM-REGISTERED_B). In this case, the state management unit  149  causes the first PLMN to transition to the registration state (RM-REGISTERED_A) and the second PLMN to transition to a deemed non-registration state (RM-REGISTERED-Inactive_B) during the second timer period T 2 . Here, the deemed non-registration state is a state where management is performed as the state of not being registered in the second management device  10 B although a registration deletion request is not made to the second management device  10 B (for example, an inactive state). Therefore, during the deemed non-registration state, the UE  1  does not receive a signal from the second network  20 B and does not transmit a signal via the second network  20 B. However, at least a part of the context related to the UE  1  during the deemed non-registration state may be continuously held by the second management device  10 B and the UE  1 . 
     When the second timer period T 2  elapses, the deregistration processing unit  148  executes the deregistration process on the first management device  10 A, and the state management unit  149  causes the first PLMN to transition to the non-registration state (RM-DEREGISTERED_A) and the second PLMN to transition to the registration state (RM-REGISTERED_B). That is, in response to the expiration of the second timer period T 2 , the UE  1  transitions the second PLMN from the deemed non-registration state (RM-REGISTERED-Inactive_B) to the registration state (RM-REGISTERED_B) without performing the reregistration process to the second network  20 B. At this time, at least a part of the context related to the UE  1  continuously held by the second management device  10 B and the UE  1  may be reused. 
     Incidentally, in a case where the third registration process is executed with the second PLMN in the non-registration state (RM-DEREGISTERED_A) and the first PLMN in the registration state (RM-REGISTERED_B), the state management unit  149  causes the first PLMN to transition to the deemed non-registration state (RM-REGISTERED-Inactive_A) and the second PLMN to transition to the registration state (RM-REGISTERED_B). Further, when the second timer period T 2  elapses, the state management unit  149  causes the first PLMN to transition to the registration state (RM-REGISTERED_A) and the second PLMN to transition to the non-registration state (RM-DEREGISTERED_B). 
     Incidentally, here, a case has been described in which the state management unit  149  does not distinguish the transitions by the first and second registration processes. However, the transitions by the respective registration processes may be distinguished and managed. In this case, the state management unit  149  manages the PLMN by dividing the PLMN into the home PLMN state (for example, RM-REGISTERED) and the visitor PLMN state (for example, RM-REGISTERED-R) by, for example, the second registration process. 
     Hereinbefore, the functional configuration examples of the management device  10  and the wireless communication device  100  according to the embodiment of the present disclosure have been described. Subsequently, an operation example of the communication system according to the embodiment of the present disclosure will be described. 
     4. OPERATION OF COMMUNICATION SYSTEM 
     &lt;4.1. Registration Activation Process&gt; 
     First, a registration activation process performed by the wireless communication device  100  will be described with reference to  FIGS. 9 to 12 . The registration activation process is a process performed before the registration process is executed. 
       FIG. 9  is a flowchart (1) illustrating an example of the registration activation process according to the embodiment of the present disclosure.  FIG. 10  is a flowchart (2) illustrating an example of the registration activation process according to the embodiment of the present disclosure.  FIG. 11  is a flowchart (3) illustrating an example of the registration activation process according to the embodiment of the present disclosure.  FIG. 12  is a flowchart (4) illustrating an example of the registration activation process according to the embodiment of the present disclosure. 
     As described above, the wireless communication device  100  activates the registration process at a predetermined timing such as when the power is turned on. Here, three cases of (1) the time the power is turned on, (2) an instruction from a user or an upper layer, and (3) an instruction from the management device  10  will be described as the predetermined timing. 
     &lt;4.1.1. When Power is Turned On&gt; 
     First, an example of the registration activation process (1) at the time the power is turned on will be described with reference to  FIG. 9 . In this case, first, the power of the wireless communication device  100  is turned on (step S 101 ). Subsequently, the switching control unit  141  of the wireless communication device  100  selects the first network  20 A connected before the power is turned off as a connection destination (step S 102 ). That is, the wireless communication device  100  (for example, the wireless communication device  100  (mobile equipment) configuring the UE  1 ) acquires the PLMN list from the first SIM  30 A (USIM). 
     Subsequently, the wireless communication device  100  executes a registration selection process (step S 103 ). 
     Incidentally, here, the wireless communication device  100  selects the previous connection destination as the selection of the connection destination at the time the power is turned on, but the present invention is not limited thereto. For example, the priority of the connection destination may be held in advance, and the wireless communication device  100  may select the connection destination (for example, PLMN) at the time the power is turned on according to the priority. 
     &lt;4.1.2. Switching Instruction from Upper Layer&gt; 
     Next, an example of the registration activation process performed on the basis of (2) an instruction from a user or an upper layer will be described with reference to  FIG. 10 . Here, it is assumed that the second network  20 B is connected. In this case, the UE  1  is registered in the second management device  10 B (for example, AMF), and the wireless communication device  100  manages the second PLMN as the home PLMN. Incidentally, it does not matter whether or not the second management device  10 B manages the first PLMN as the visitor PLMN. 
     As illustrated in  FIG. 10 , when receiving an instruction (for example, a PLMN switching instruction or a SIM  30  (USIM) switching instruction) to switch the connection destination of the network  20  from the user or the upper layer, the wireless communication device  100  determines the switching of the network  20  (step S 201 ). 
     Subsequently, the deregistration processing unit  148  of the wireless communication device  100  executes the deregistration process on the second management device  10 B belonging to the second PLMN which is the home PLMN (step S 202 ). 
     The switching control unit  141  of the wireless communication device  100  selects the first network  20 A as the connection destination in accordance with the switching instruction from the user or the upper layer (step S 203 ). Then, the wireless communication device  100  executes the registration selection process (step S 103 ). 
     &lt;4.1.3. Switching Instruction from Management Device&gt; 
     An example of the registration activation process performed on the basis of (3) an instruction from the management device  10  will be described with reference to  FIGS. 11 and 12 . In this case, the first PLMN is managed as the visitor PLMN in the second management device  10 B. 
     Here, first, a case where the wireless communication device  100  receives a complete switching instruction from the second management device  10 B will be described with reference to  FIG. 11 , and next, a case where the wireless communication device  100  receives a temporary switching instruction will be described with reference to  FIG. 12 . 
     (Complete Switching Instruction) 
     As illustrated in  FIG. 11 , the wireless communication device  100  receives the complete switching instruction from the second management device  10 B (step S 301 ). When receiving the complete switching instruction, the wireless communication device  100  determines switching of the network  20  (step S 302 ). 
     Subsequently, the deregistration processing unit  148  of the wireless communication device  100  executes the deregistration process on the second management device  10 B belonging to the second PLMN which is the home PLMN (step S 303 ). 
     The switching control unit  141  of the wireless communication device  100  selects the first network  20 A as the connection destination in accordance with the complete switching instruction (step S 304 ). Then, the wireless communication device  100  executes the registration selection process (step S 103 ). 
     (Temporary Switching Instruction) 
     As illustrated in  FIG. 12 , the wireless communication device  100  receives the temporary switching instruction from the second management device  10 B (step S 401 ). When receiving the temporary switching instruction, the wireless communication device  100  determines temporary switching of the network  20  during the second timer period T 2  (step S 402 ). 
     In this case, unlike a case where the complete switching instruction is received, the wireless communication device  100  selects the first PLMN (in other words, the first network  20 A) as the connection destination without executing the deregistration process on the second management device  10 B (in other words, does not become in RM-DEREGISTERED) (step S 403 ). Then, the wireless communication device  100  executes the third registration process (step S 404 ). Specifically, the registration processing unit  147  of the wireless communication device  100  transmits the third Registration request including the second timer period T 2  as the third registration process to the first management device  10 A. 
     &lt;4.2. Registration Selection Process&gt; 
     Next, an example of the registration selection process will be described with reference to  FIG. 13 .  FIG. 13  is a flowchart illustrating an example of the registration selection process according to the embodiment of the present disclosure. The registration selection process is executed, for example, with the registration activation process by the wireless communication device  100  as a trigger. 
     As illustrated in  FIG. 13 , the first acquisition unit  142  of the wireless communication device  100  acquires the information regarding the PLMN stored in the first SIM  30 A (step S 501 ). The first acquisition unit  142  acquires, for example, the first PLMN list  40 . 
     Subsequently, the selection unit  143  of the wireless communication device  100  selects an HPLMN from the first PLMN list  40  (step S 502 ). Next, the second acquisition unit  144  of the wireless communication device  100  acquires the information regarding the PLMN stored in the second SIM  30 B (step S 503 ). The second acquisition unit  144  acquires the second PLMN ID from the second SIM  30 B, for example. 
     The determination unit  145  of the wireless communication device  100  determines whether or not the second PLMN ID is included in the first PLMN list  40  (step S 504 ). In a case where the second PLMN ID is not included in the first PLMN list  40  (step S 504 ; No), the registration selection unit  146  of the wireless communication device  100  selects the first registration process for the first management device  10 A belonging to the HPLMN (step S 505 ). 
     On the other hand, in a case where the second PLMN ID is included in the first PLMN list  40  (step S 504 ; Yes), the registration selection unit  146  determines the second PLMN as the visitor PLMN (step S 506 ), and selects the second registration process for the first management device  10 A (step S 507 ). 
     &lt;4.3. Details of Registration Selection Process&gt; 
     Details of the registration selection process including the communication with the SIM  30  will be described with reference to  FIG. 14 .  FIG. 14  is a sequence diagram for explaining the registration selection process. 
     The wireless communication device  100  (hereinafter, also referred to as a mobile equipment (ME) 100) performs a USIM initialization procedure. More specifically, the ME  100  transmits an equivalent home PLMN (EHPLMN) request to acquire information in elementary file_EHPLMN (EF_EHPLMN) in the first SIM  30 A (USIM) (step S 601 ). In response to this, the first SIM  30 A transmits an EHPLMN response (step S 602 ). Accordingly, the wireless communication device  100  acquires an EHPLMN list from the first SIM  30 A. 
     Next, the wireless communication device  100  transmits a forbidden PLMN request to acquire information in EF_FPLMN in the first SIM  30 A (USIM) (step S 603 ). In response, the first SIM  30 A transmits a forbidden PLMN response (step S 604 ). Accordingly, the wireless communication device  100  acquires a forbidden PLMN list which is an unselectable PLMN. 
     The wireless communication device  100  selects a HPLMN from the first PLMN list  40  obtained by removing the forbidden PLMN from the EHPLMN list (step S 605 ). On the basis of the priority, the wireless communication device  100  selects, as the HPLMN, an available PLMN with a higher priority among PLMN candidates which are included in the EHPLMN list and are not included in the forbidden PLMN list, for example. 
     Here, in a case where the EHPLMN list does not exist, or the EHPLMN list is empty, the wireless communication device  100  may request the first SIM  30 A to transmit a subscriber permanent identifier (SUPI). In this case, the wireless communication device  100  selects the HPLMN included in the SUPI to which the first SIM  30 A responds. At this time, the wireless communication device  100  may transmit an HPLMN selector with Access Technology request to the first SIM  30 A, and check an access technology (for example, 5G (NR) or 4G (EUTRA)) supported by the HPLMN acquired from the SUPI from the information obtained as a result of the response. 
     The wireless communication device  100  may transmit an Operator controlled PLMN Selector with Access Technology request and a User Controlled PLMN Selector with Access Technology request to the first SIM  30 A in addition to the EHPLMN request. In this case, the wireless communication device  100  may select an HPLMN from the first PLMN list  40  included in the response from the first SIM  30 A. Incidentally, the wireless communication device  100  only needs to transmit at least one of the EHPLMN request, the Operator controlled PLMN Selector with Access Technology request, and the User Controlled PLMN Selector with Access Technology request to the first SIM  30 A, and does not necessarily need to transmit all of them. 
     Subsequently, the wireless communication device  100  requests the SUPI as the second PLMN ID from the second SIM  30 B (step S 606 ). In response to this, the second SIM  30 B transmits a SUPI response (step S 607 ). Accordingly, the wireless communication device  100  acquires the second PLMN ID. 
     Incidentally, here, the wireless communication device  100  acquires the second PLMN ID, but the present invention is not limited thereto. The wireless communication device  100  may acquire a second PLMN list including a plurality of second PLMN IDs. In this case, similarly to the first PLMN list  40 , the wireless communication device  100  may acquire the second PLMN list on the basis of the EHPLMN list and the forbidden PLMN list which are stored in the second SIM  30 B. 
     The wireless communication device  100  determines whether or not the second PLMN ID is included in the first PLMN list  40 , and selects a Registration request to be transmitted to the first management device  10 A (step S 608 ). 
     Incidentally, in the case of acquiring the second PLMN list from the second SIM  30 B, for all the second PLMN candidates included in the second PLMN list, the wireless communication device  100  determines whether or not the second PLMN candidate is included in the first PLMN list  40 . In a case where all the second PLMN candidates are not included in the first PLMN list  40 , the wireless communication device  100  determines to execute the first registration process. 
     On the other hand, in a case where at least one of the second PLMN candidates is included in the first PLMN list  40 , the wireless communication device  100  determines to execute the second registration process. At this time, when there is one second PLMN candidate included in the first PLMN list  40 , the wireless communication device  100  determines the relevant second PLMN candidate as the second PLMN to be included in the second Registration. In a case where there is a plurality of second PLMN candidates included in the first PLMN list  40 , the wireless communication device  100  determines a second PLMN candidate with a higher priority as the second PLMN to be included in the second Registration. 
     &lt;4.4. Registration Process&gt; 
     Subsequently, the registration process performed by the wireless communication device  100  will be described with reference to  FIGS. 15 to 18 . Incidentally, in the following description, in addition to the registration process by the wireless communication device  100 , the communication with the management device  10  will also be described. 
     &lt;4.4.1. First Registration Process&gt; 
     First, the first registration process will be described with reference to  FIG. 15 .  FIG. 15  is a sequence diagram for explaining an example of the first registration process. The first registration process is selected in a case where the second PLMN ID is not included in the first 
     PLMN list  40 . In  FIG. 15 , the flow of the first registration process including the registration activation process will be described by taking a case where an instruction from the upper layer is received as an example. 
     The wireless communication device  100  performs management in a state where the UE  1  (or the wireless communication device  100 ) is not registered in the first management device  10 A (RM-DEREGISTERED_A), and the UE  1  is registered in the second management device  10 B (RM-REGISTERED_B) (step S 701 ). In this state, when there is an instruction from the upper layer, the wireless communication device  100  determines the switching of the network  20 , that is, the switching of the registration destination PLMN (step S 702 ). 
     The wireless communication device  100  transmits a Deregistration (registration deletion) request to the second management device  10 B in which the UE  1  is registered (step S 703 ). The wireless communication device  100  causes both the first and second PLMNs to transition to the non-registration (RM-DEREGISTERED_A, RM-DEREGISTERED_B) state (step S 704 ). 
     The wireless communication device  100  selects the first network  20 A as the network  20  (for example, a network to be switched with the switching of the SIM  30  (USIM)) to be switched (step S 705 ). In other words, the wireless communication device  100  selects the first PLMN as the PLMN to be registered, and executes the registration selection process (step S 706 ). 
     The wireless communication device  100  which selects the first registration process in the registration selection process executes the following first registration process. 
     First, the wireless communication device  100  transmits a Registration request to the first management device  10 A (step S 707 ). At this time, the wireless communication device  100  transmits the Registration request without including the second PLMN ID. 
     Here, when the 5G-globally unique temporary identifier (GUTI) allocated from the first PLMN to which the first management device  10 A belongs is available, the wireless communication device  100  transmits the Registration request with the 5G-GUTI included therein. On the other hand, in a case where the allocated 5G-GUTI is not available, the wireless communication device  100  transmits the Registration request with the 5G-GUTI allocated from another PLMN (for example, the second PLMN to which the second management device  10 B belongs), included therein. 
     Incidentally, in a case where the wireless communication device  100  does not have the available 5G-GUTI, the wireless communication device  100  transmits the Registration request with a subscription concealed identifier (SUCI) generated from the SUPI stored in the first SIM  30 A, included therein. 
     Subsequently, when registering the UE  1 , the first management device  10 A transmits a Registration accept to the wireless communication device  100  (step S 708 ). 
     Here, in the case of not acquiring a permanent equipment identifier (PEI) which is identification information (UE identity) of the UE  1 , the first management device  10 A transmits an identity request to the wireless communication device  100  to acquire the PEI of the UE  1 . The PEI is, for example, an international mobile equipment identity (IMEI). Incidentally, the first management device  10 A may acquire the SUCI instead of the PEI. 
     The wireless communication device  100  transitions the first PLMN to the registration state (RM-REGISTERED_A) and the second PLMN to the non-registration (RM-DEREGISTERED_B) state (step S 709 ), and ends the first registration process. 
     Incidentally, here, the wireless communication device  100  causes both the first and second PLMNs to transition to the non-registration state after transmitting the Deregistration request, but the present invention is not limited thereto. For example, the wireless communication device  100  may transition the states of the first and second PLMNs after receiving the Registration accept. In this case, the wireless communication device  100  can directly transition the states of the first and second PLMNs from “RM-DEREGISTERED_A, RM-REGISTERED_B” to “RM-REGISTERED_A, RM-DEREGISTERED_B”. Incidentally, such a transition may be similarly performed also in the following  FIGS. 16 and 17 . 
     &lt;4.4.2. Second Registration Process&gt; 
     Next, the second registration process will be described with reference to  FIG. 16 .  FIG. 16  is a sequence diagram for explaining an example of the second registration process. The second registration process is selected in a case where the second PLMN ID is included in the first PLMN list  40 . Incidentally, the registration activation process is the same as that in  FIG. 15 , and thus the same reference signs are given, and the description thereof is omitted. 
     The wireless communication device  100  which selects the second registration process in the registration selection process in step S 706  executes the following second registration process. 
     First, the wireless communication device  100  transmits a second Registration request to the first management device  10 A (step S 801 ). The second Registration request includes the second PLMN ID. 
     Here, when the 5G-GUTI allocated from the first PLMN to which the first management device  10 A belongs is available, the wireless communication device  100  transmits the second Registration request with the 5G-GUTI included therein. On the other hand, in a case where the allocated 5G-GUTI is not available, the wireless communication device  100  transmits the second Registration request with the 5G-GUTI allocated from another PLMN (for example, the second PLMN to which the second management device  10 B belongs), included therein. 
     Incidentally, in a case where the wireless communication device  100  does not have the available 5G-GUTI, the wireless communication device  100  transmits the second Registration request with the SUCI generated from the SUPI stored in the first SIM  30 A, included therein. 
     The wireless communication device  100  may include information regarding the paging priority in the second Registration request. Here, the information regarding the paging priority is information indicating priorities of the first paging addressed to the SUPI stored in the first SIM  30 A and the second paging addressed to the SUPI stored in the second SIM  30 B. In a case where the timings of the first paging and second paging overlap, the first management device  10 A gives priority to one paging on the basis of such information. In a case where such information is not included in the second Registration request, the first management device  10 A may prioritize the first paging addressed to the SUPI stored in the first SIM  30 A managed as the home PLMN. 
     Subsequently, the first management device  10 A which receives the second Registration request registers the UE  1  and registers the second PLMN ID as the visitor PLMN (step S 802 ). 
     Here, in the case of not acquiring a permanent equipment identifier (PEI) which is identification information (UE identity) of the UE  1 , the first management device  10 A transmits an identity request to the wireless communication device  100  to acquire the PEI of the UE  1 . The PEI is, for example, IMEI. Incidentally, the first management device  10 A may acquire the SUCI instead of the PEI. 
     The first management device  10 A notifies the second management device  10 B belonging to the second PLMN that the second PLMN is registered as the visitor PLMN (step S 803 ). Further, the first management device  10 A transmits a second Registration accept to the wireless communication device  100  to notify that the registration of the UE  1  is completed (step S 804 ). 
     The wireless communication device  100  transitions the first PLMN to the registration state (RM-REGISTERED_A) and the second PLMN to the non-registration (RM-DEREGISTERED_B) state (step S 805 ), and ends the second registration process. Here, the wireless communication device  100  may receive a notification indicating that the second PLMN is registered as the visitor PLMN via the second Registration accept message, and transition the first PLMN to the home PLMN registration state (RM-REGISTERED_A) and the second PLMN to the visitor PLMN registration state (RM-REGISTERED_R_B). Accordingly, the wireless communication device  100  monitors the first paging addressed to the SUPI stored in the first SIM  30 A and the second paging addressed to the SUPI stored in the second SIM  30 B for the network of the first PLMN to which the first management device  10 A belongs. 
     A flow until the second registration process is executed in a case where an instruction from the management device  10  is received will be described with reference to  FIG. 17 .  FIG. 17  is a sequence diagram for explaining another example of the second registration process. 
     In a state where the first PLMN is managed as the non-registration state (RM-DEREGISTERED_A), and the second PLMN is managed as the registration state (RM-REGISTERED_B), the wireless communication device  100  receives Notification_SIM_SW from the second management device  10 B (step S 901 ). Notification_SIM_SW is a complete switching instruction that instructs switching of the connection destination network  20 , that is, switching of the registration destination PLMN. Incidentally, the second management device  10 B may transmit Notification_SIM_SW with a unique identifier of the network of the switching destination included therein. Here, examples of the unique identifier of the network include a PLMN ID, a non-public network (NPN) ID, and a neutral host network (NHN) ID. 
     When transmitting Notification_SIM_SW, the second management device  10 B starts measuring the timer period T (step S 902 ). 
     The wireless communication device  100  which receives Notification_SIM_SW determines the switching of the network  20 , that is, the switching of the PLMN to be registered according to the instruction from the second management device  10 B (step S 702 ). 
     The second management device  10 B which receives the Deregistration request from the wireless communication device  100  (step S 703 ) stops measuring the timer period T (step S 904 ). Incidentally, in a case where the timer period T has elapsed before receiving the Deregistration request, the second management device  10 B returns to step S 901  and retransmits Notification_SIM_SW. 
     Incidentally, the second management device  10 B may determine whether or not to transmit Notification_SIM_SW to the UE  1  on the basis of the UE radio capability acquired from the UE  1 . That is, the second management device  10 B transmits Notification_SIM_SW to the UE  1  having such UE radio capability that a plurality of SIMs  30  can be mounted. On the other hand, Notification_SIM_SW is not transmitted to the UE  1  having such UE radio capability that does not support a plurality of SIMs  30 . 
     &lt;4.4.3. Third Registration Process&gt; 
     Next, the third registration process will be described with reference to  FIG. 18 .  FIG. 18  is a sequence diagram for explaining an example of the third registration process. The third registration process is executed in a case where the temporary switching instruction is received from the management device  10 . In  FIG. 18 , the flow of the third registration process including the reception of the temporary switching instruction from the second management device  10 B will be described. 
     For example, in a case where a notification (paging notification) regarding paging addressed to the wireless communication device  100  is received from the first management device  10 A (step S 1001 ), the second management device  10 B transmits second Notification_SIM_SW to the wireless communication device  100  (step S 1002 ) and starts measuring the first timer period T 1  (step S 1003 ). The second Notification_SIM_SW is a temporary switching instruction including the first timer period T 1 . 
     The second management device  10 B may include the first PLMN ID corresponding to the first SIM  30 A in the second Notification_SIM_SW. Further, the second management device  10 B may include a third timer period T 3  to be described later instead of the first timer period T 1 . 
     When receiving the second Notification_SIM_SW from the second management device  10 B, the wireless communication device  100  starts measuring the third timer period T 3  according to the first timer period T 1  (step S 1004 ). The third timer period T 3  may be a same period as the first timer period T 1  or may be a period shorter than the first timer period T 1 . 
     The wireless communication device  100  determines the switching of the network  20 , that is, the switching of the PLMN to be registered according to the instruction from the second management device  10 B (step S 1005 ). Further, the wireless communication device  100  selects the first network  20 A as the network  20  to be switched (step S 1006 ). In other words, the wireless communication device  100  selects the first PLMN as the PLMN to be registered. 
     Subsequently, the wireless communication device  100  executes the third registration process described below. 
     Specifically, the wireless communication device  100  transmits a third Registration request to the first management device  10 A (step S 1007 ). The third Registration request includes the second timer period T 2  according to the first and third timer periods T 1  and T 3 . Incidentally, the second timer period T 2  may be the same as or shorter than the first and third timer periods T 1  and T 3 . 
     Here, when the 5G-GUTI allocated from the first PLMN to which the first management device  10 A belongs is available, the wireless communication device  100  transmits the third Registration request with the 5G-GUTI included therein. On the other hand, in a case where the allocated 5G-GUTI is not available, the wireless communication device  100  transmits the third Registration request with the 5G-GUTI allocated from another PLMN (for example, the second PLMN to which the second management device  10 B belongs), included therein. 
     Incidentally, in a case where the wireless communication device  100  does not have the available 5G-GUTI, the wireless communication device  100  transmits the third Registration request with the SUCI generated from the SUPI stored in the first SIM  30 A, included therein. 
     When receiving the third Registration request, the first management device  10 A transmits a third Registration accept (step S 1008 ) and starts measuring the second timer period T 2  (step S 1009 ). 
     Here, in the case of not acquiring a permanent equipment identifier (PEI) which is identification information (UE identity) of the UE  1 , the first management device  10 A transmits an identity request to the wireless communication device  100  to acquire the PEI of the UE  1 . The PEI is, for example, IMEI. Incidentally, the first management device  10 A may acquire the SUCI instead of the PEI. 
     Subsequently, the first management device  10 A manages the first PLMN stored in the first SIM  30 A as the registration state (RM-REGISTERED_A) (step S 1010 ). The first management device  10 A transmits paging addressed to the SUPI stored in the first SIM  30 A to the wireless communication device  100  during the second timer period T 2 . 
     The wireless communication device  100  which receives the third Registration accept manages the first PLMN as the registration state (RM-REGISTERED_A) and the second PLMN as the deemed non-registration state (RM-REGISTERED-Inactive_B) (step S 1011 ). The wireless communication device  100  receives paging from the first management device  10 A after receiving the third Registration accept until the third timer period T 3  ends. The wireless communication device  100  receives paging via, for example, the gNB/ng-eNB belonging to the first PLMN included in the second Notification_SIM_SW. 
     When the third timer period T 3  ends (step S 1012 ), the wireless communication device  100  causes the first PLMN to transition to the non-registration state (RM-DEREGISTERED_A) and the second PLMN to transition to the registration state (RM-REGISTERED_B) (step S 1013 ). 
     The wireless communication device  100  transmits Notification_SIM_SW Complete to the second management device  10 B to notify that the communication with the first management device  10 A is ended (step S 1014 ). The second management device  10 B which receives Notification_SIM_SW Complete stops measuring the first timer period T 1  (step S 1015 ). Thereafter, the second management device  10 B resumes the stopped communication with the wireless communication device  100 , for example. In other words, in a case where a paging request addressed to the SUPI stored in the second SIM  30 B is generated during the measurement of the first timer period T 1 , the second management device  10 B executes paging after waiting for the end of the first timer period T 1  (or the stop of measurement). 
     In a case where the second timer period T 2  ends after starting the measurement of the second timer period T 2  in step S 1009  (step S 1016 ), the first management device  10 A deletes the registration of the UE  1  and causes the UE  1  to transition to the non-registration state (RM-DEREGISTERED_A) (step S 1017 ). 
     As described above, by registering the first PLMN only for a time, the wireless communication device  100  can omit the registration deletion request transmitted to the second management device  10 B after determining the switching of the SIM  30 . Further, the registration deletion request transmitted from the wireless communication device  100  to the first management device  10 A after the third timer period T 3  ends can be omitted. Therefore, traffic between the wireless communication device  100  and the management device  10  can be reduced. 
     Incidentally, here, the wireless communication device  100  waits for the end of the third timer period T 3  and deletes the registration of the first PLMN, but the present invention is not limited thereto. For example, in a case where the communication regarding the paging generated in the first network  20 A ends, the registration of the first PLMN may be deleted without waiting for the end of the third timer period T 3 . 
     As described above, when the registration of the first PLMN and the UE  1  is deleted at the time when the communication ends without waiting for the end of the second and third timer periods T 2  and T 3 , it is possible to shorten an interruption time from the first management device  10 A and lengthen a communication time between the wireless communication device  100  and the second management device  10 B. 
     The wireless communication device  100  transmits Notification_SIM_SW Complete, but the present invention is not limited thereto. For example, the transmission of Notification_SIM_SW Complete by the wireless communication device  100  may be omitted. In this case, the second management device  10 B waits for the end of the first timer period T 1  and resumes the communication with the wireless communication device  100 . Accordingly, the transmission of Notification_SIM_SW Complete by the wireless communication device  100  can be omitted, and the traffic between the wireless communication device  100  and the second management device  10 B can be reduced. 
     Further, in a case where the first management device  10 A transmits a paging notification to the second management device  10 B, the information regarding the second timer period T 2  may be included in the paging notification. Alternatively, the first management device  10 A may include information regarding the size of data to be transmitted by paging in the paging notification. 
     As described above, the first management device  10 A notifies the second management device  10 B of the information regarding the timer and the size of the data, so that the period for switching the connection destination can be set to an appropriate period according to the size of the data. 
     (Network Slicing) 
     Here, in  FIG. 18 , a case where paging notified from the first management device  10 A to the second management device  10 B relates to a service by a specific network slice will be described. In this case, the first management device  10 A includes, for example, network slice selection assistance information (NSSAI) corresponding to the network slice in the paging notification transmitted in step S 1001  of  FIG. 18 . 
     The second management device  10 B includes NSSAI in the second Notification_SIM_SW transmitted in step S 1002 . The wireless communication device  100  which receives the second Notification_SIM_SW selects the first SIM  30 A corresponding to the first PLMN ID included in the second Notification_SIM_SW. The wireless communication device  100  transmits, to the first management device  10 A, the third Registration request with the requested NSSAI included therein in step S 1007 . In the case of permitting the registration, the first management device  10 A which receives the third Registration request including the requested NSSAI transmits the third Registration accept including the allowed NSSAI in step S 1008 . 
     As described above, even when the paging relating to the service by the network slice occurs in the first network  20 A, the wireless communication device  100  can appropriately switch the connection destination network  20  and perform paging. 
     &lt;4.5. Selection Process of Switching Instruction&gt; 
     Subsequently, a switching instruction selection process performed by the management device  10  will be described with reference to  FIG. 19 .  FIG. 19  is a flowchart for explaining the switching instruction selection process. Here, a case where the second management device  10 B selects a switching instruction to be transmitted to the wireless communication device  100  will be described. It is assumed that the second management device  10 B manages the first PLMN as the visitor PLMN and the second PLMN as the home PLMN. 
     When receiving a notification (paging notification) regarding paging from the first PLMN via the first management device  10 A (step S 1101 ), the second management device  10 B determines whether or not to transmit a switching instruction to the wireless communication device  100  (step S 1102 ). The second management device  10 B determines whether or not to transmit the switching instruction according to, for example, the first PLMN or the contract with the user. Alternatively, the second management device  10 B may determine whether the paging notification is a switching request of the network  20  or a paging transmission request via the second network  20 B. In other words, whether or not to transmit the switching instruction may be determined according to a request from the first management device  10 A. 
     In a case where it is determined not to transmit the switching instruction (step S 1102 ; No), the second management device  10 B executes paging for the wireless communication device  100  according to the paging notification received via the first management device  10 A (step S 1103 ). 
     For example, in a case where a roaming agreement is made with the first PLMN, the second management device  10 B may provide a service similar to the first PLMN to the wireless communication device  100 . In this regard, the second management device  10 B executes paging addressed to the wireless communication device  100  generated in the first network  20 A instead of the first management device  10 A without transmitting the switching instruction. 
     On the other hand, in a case where it is determined to transmit the switching instruction (step S 1102 ; Yes), the second management device  10 B determines whether or not the paging size is equal to or larger than a predetermined threshold Th 1  on the basis of the paging notification (step S 1104 ). 
     In a case where the paging size is equal to or larger than the predetermined threshold Th 1  (step S 1104 ; Yes), the second management device  10 B selects a complete switching instruction to completely switch the connection destination network  20  (step S 1105 ). On the other hand, in a case where the paging size is less than the predetermined threshold Th 1  (step S 1104 ; No), the second management device  10 B selects a temporary switching instruction to temporarily switch the connection destination during the first timer period T 1  (step S 1106 ). The second management device  10 B transmits the selected switching instruction to the wireless communication device  100  (step S 1107 ), and ends the process. 
     As described above, in a case where the paging size is small, by temporarily switching the connection destination network  20 , the number of complete switching times of the connection destination including the registration deletion request can be reduced, and the traffic of the network  20  can be reduced. 
     Incidentally, in step S 1101 , it is assumed that paging addressed to the wireless communication device  100  also occurs in the second network  20 B at the timing of receiving the paging notification from the first network  20 A. In this case, the second management device  10 B determines prioritized paging according to the paging priority. The paging priority is included in the second Registration request from the wireless communication device  100 . In a case where the second PLMN is prioritized, the second management device  10 B responds to the paging from the second network  20 B, and then proceeds to step S 1102 . On the other hand, in a case where the first PLMN is prioritized, the second management device  10 B directly proceeds to step S 1102 . After the wireless communication device  100  receives the paging generated in the first network  20 A, the second management device  10 B transmits the paging generated in the second network  20 B to the wireless communication device  100 . 
     5. APPLICATION EXAMPLE 
     &lt;5.1. Application Example of Radio Access Technology&gt; 
     The technology according to the present disclosure can be applied to another radio access technology. For example, the communication system may employ LTE as a radio access technology or may employ both LTE and NR. 
     &lt;5.1.1. Application Example to LTE&gt; 
     (Configuration Example of Network Architecture) 
     First, a case where the communication system according to the present disclosure adopts LTE will be described.  FIG. 20  is a diagram illustrating an example of a network architecture configuration of LTE. The network architecture illustrated in  FIG. 20  includes the UE  1  and first and second core networks  20 LA and  20 LB. In  FIG. 20 , the UE  1  is connected with the first core network  20 LA, but the UE  1  is also connectable with the second core network  20 LB. 
     The first and second core networks  20 LA and  20 LB are connected to each other via a point of interface (POI)  2000 L. 
     The core network  20 L includes an eNB  3001 , an MME  3002 , a serving gateway (S-GW)  3003 , a packet data network gateway (P-GW)  3004 , and a home subscriber server (HSS)  3005 . 
     The eNB  3001  functions as a base station of LTE. The MME  3002  is a control node which handles a signal of a control plane, and manages a moving state of a terminal device. The S-GW  3003  is a control node which handles a signal of a user plane, and is a gateway device which switches a transfer path of user data. The P-GW  3004  is a control node which handles the signal of the user plane, and is a gateway device serving as a connection point between the core network  20 L and the PDN  3000 . The HSS  3005  is a control node which handles subscriber data and performs service control. The management device  10  is a device which realizes the functions of the MME  3002 . Further, the management device  10  may have a function as the S-GW  3003  or the P-GW  3004 . 
     In  FIG. 20 , the interface provided for signal transmission in the core network  20 L is indicated by a solid line. As illustrated in  FIG. 20 , the eNB  3001  is connected to the MME  3002  via an S1-MME interface, and is connected to the S-GW  3003  via an S1-U interface. The S-GW  3003  is connected to the MME  3002  via an S11 interface, and the MME  3002  is connected to the HSS  3005  via an S6a interface. The P-GW  3004  is connected to the S-GW  3003  via an S5/S8 interface. 
     As indicated by a dotted line in  FIG. 20 , in a case where there is, for example, a roaming agreement between the first and second MNOs, an interface for transmission of signals and data between the first and second core networks  20 LA and  20 LB is provided. In the example of  FIG. 20 , an MME  3002 B is connected to a HSS  3005 A via the S6a interface, and an S-GW  3003 B is connected to a P-GW  3004 A via the S8 interface. An MME  3002 A is connected to a HSS  3005 B via the S6a interface, and an S-GW  3003 A is connected to a P-GW  3004 B via the S8 interface. 
     (State Transition) 
     Subsequently, the state transition of the UE  1  (or the wireless communication device  100 ) in LTE will be described. First, the state transition managed by the core network  20  will be described, and then the state transition managed by the UE  1  will be described. 
     First, the state transition of the UE  1  managed by the state management unit  131  of the management device  10  will be described with reference to  FIGS. 21 and 22 . In the case of LTE, the management device  10  manages two state transitions of an EPS mobility management (EMM) and an EPS connection management (ECM). 
     (EMM State Transition 1) 
     First, the state transition of the EMM will be described with reference to  FIG. 21 .  FIG. 21  is a diagram illustrating an example of the EMM state transition. 
     The state transition of the EMM depends on whether the UE  1  is registered in an EPC. When the power of the UE  1  is turned on, and the UE  1  is registered in the management device  10 , the management device  10  causes the UE  1  to transition to EMM-REGISTERED. Incidentally, here, it is assumed that the management device  10  has the functions of the MME  3002  and the S-GW  3003 , notifies the UE  1  of an IP address when receiving an Attach request from the UE  1 , establishes a default EPS bearer, and registers the UE  1 . Alternatively, the management device  10  may register the UE  1  in a case where the management device  10  has the function of the MME  3002 , and transition the UE  1  to EMM-REGISTERED in a case where another device having the function of the S-GW  3003  registers the UE  1 . 
     When the power of UE  1  is turned off or UE  1  is out of the range, the management device  10  deletes the registration of the UE  1  and transitions the state of the UE  1  to EMM-DEREGISTERED. When receiving a Detach request from the UE  1 , the management device  10  transitions the state of the UE  1  to EMM-DEREGISTERED. 
     Incidentally, in a case where the state of the UE  1  is in EMM-DEREGISTERED, the UE  1  is not registered in the MME  3002  and the S-GW  3003 , and the UE  1  is in a state with no IP address or default EPS bearer. 
     (ECM State Transition 1) 
       FIG. 22  is a diagram illustrating an example of the state transition of the ECM. The management device  10  manages two states of ECM-IDLE and ECM-CONNECTED (or also referred to as EMM-IDLE and EMM-CONNECTED). When receiving a Service request from the UE  1 , the management device  10  transitions the state of the UE  1  from ECM-IDLE to ECM-CONNECTED. Further, when receiving an S1 Release from the UE  1 , the management device  10  transitions the state of the UE  1  from ECM-CONNECTED to ECM-IDLE. 
     The state transition of the ECM depends on whether the UE  1  is in an active state or a standby state in terms of a non-access stratum (NAS) protocol and the EPC. That is, in a case where the UE  1  is in the active state, the management device  10  sets the UE  1  to ECM-CONNECTED. In this state, the management device  10  grasps the eNB/gNB to which the UE  1  belongs. Further, a signaling radio bearer is established with the UE  1 , and the UE  1  can exchange control messages with the MME  3002 . Further, a data bearer is established with the UE  1 , and the UE  1  can exchange data with the S-GW  3003 . 
     On the other hand, in a case where the UE  1  is in the standby state, the management device  10  sets the UE  1  to ECM-IDLE. In the case of ECM-IDLE, the network  20  releases the S1 Bearer and Radio Bearer of the UE  1 , but the EPS Bearer is secured to secure logical connection. 
     Incidentally, in the case of ECM-IDLE, the management device  10  does not accurately grasp the position of the UE  1 , and manages the position of the UE  1  within a range of a tracking area (TA). Therefore, when TA changes, the UE  1  executes TA Update. Further, the management device  10  transmits paging to the UE  1  in the TA unit to which the UE  1  belongs. 
     (RRC State Transition 1) 
     Incidentally, in LTE, for example, the eNB  3001  manages an RRC state transition.  FIG. 23  is a diagram illustrating an example of the state transition of the RRC. 
     The state transition of the RRC depends on whether the UE  1  is in the active state or the standby state from the viewpoint of an access stratum (AS) protocol and an evolved universal terrestrial radio access network (E-UTRAN). That is, in a case where the UE  1  is in the active state, the eNB  3001  sets the UE  1  as RRC-CONNECTED. In this state, a serving eNB/en-gNB or a serving cell which performs communication is allocated to the UE  1 . The UE  1  communicates with the allocated serving eNB/en-gNB by using a control message on a signaling radio bearer (SRB)  1 . 
     On the other hand, in a case where the UE  1  is in the standby state, the eNB  3001  sets the UE  1  to RRC-IDLE. In this state, the radio access network (RAN) does not grasp the UE  1 , and the serving eNB/en-gNB or the serving cell is not allocated. Further, the SRB  1  is released. In RRC-IDLE, the UE  1  starts some limited communications (for example, the reception of system information). For example, when receiving a paging request from the EPC, the RAN is connected to the UE  1  by using the RRC paging message. 
     Further, in a case where the UE  1  is connected to the RAN or a case where the UE  1  responds to the paging message, the UE  1  executes the RRC connection establishment process (for example, a random access procedure and an RRC (Connection) setup procedure). In response to such a process, when the RAN accepts the establishment of the RRC connection, the eNB  3001  causes the state of the UE  1  to transition to RRC-CONNECTED. 
     Incidentally, except for a transient state, the UE  1  in the standby state is always managed as ECM-IDLE and RRC-IDLE, and the UE  1  in the active state is always managed as ECM-CONNECTED and RRC-CONNECTED. 
     (EMM State Transition 2) 
     Subsequently, the state transition of the EMM in the wireless communication device  100  will be described.  FIG. 24  is a diagram illustrating an example of the state transition of the EMM in the wireless communication device  100 . The state management unit  149  of the wireless communication device  100  manages, as the state of the UE  1 , the registration state (EMM-REGISTERED) registered in the management device  10  and the non-registration state (EMM-DEREGISTERED) not registered for each PLMN. 
     In the case of being not registered in either of the first and second management devices  10 A and  10 B, for example, when the power is turned on, the wireless communication device  100  manages both the first and second PLMNs as the non-registration state (EMM-DEREGISTERED_A, EMM-DEREGISTERED_B). 
     Here, it is assumed that the registration processing unit  147  of the wireless communication device  100  performs first or second attach process on the first management device  10 A. In this case, the wireless communication device  100  manages the first PLMN as the registration state (EMM-REGISTERED_A) and the second PLMN as the non-registration state (EMM-DEREGISTERED_B). Incidentally, the first and second attach processes here are processes for requesting registration to the management device  10 , and are processes corresponding to the first and second registration processes in NR described above. 
     On the other hand, it is assumed that the deregistration processing unit  148  of the wireless communication device  100  requests the first management device  10 A to delete (detach) the registration of the UE  1  in the “EMM-REGISTERED_A, EMM-DEREGISTERED_B” state. In this case, the wireless communication device  100  manages both the first and second PLMNs as the non-registration state “EMM-DEREGISTERED_A, EMM-DEREGISTERED_B”. 
     It is assumed that the switching control unit  141  of the wireless communication device  100  selects to perform the first or second attach processes on the second management device  10 B with both the first and second PLMNs in the non-registration state (EMM-DEREGISTERED_A, EMM-DEREGISTERED_B). In this case, the wireless communication device  100  causes the first PLMN to transition to the non-registration state (EMM-DEREGISTERED_A) and the second PLMN to transition to the registration state (EMM-REGISTERED_B). 
     In a case where the second management device  10 B is requested to delete the registration of the UE  1  in the “EMM-DEREGISTERED_A, EMM-REGISTERED_B” state, the wireless communication device  100  causes both the first and second PLMNs to transition to the non-registration state (EMM-DEREGISTERED_A, EMM-DEREGISTERED_B). 
     (ECM State Transition 2) 
     Subsequently, the state transition of the ECM in the wireless communication device  100  will be described.  FIG. 25  is a diagram illustrating an example of the state transition of the ECM in the wireless communication device  100 . The state management unit  149  of the wireless communication device  100  manages ECM-CONNECTED and ECM-IDLE as the active/standby state of the UE  1  for each PLMN. 
     In a case where both the first and second PLMNs are in ECM-IDLE (ECM-IDLE_A, ECM-IDLE_B), the wireless communication device  100  performs a service request process on the first core network  20 A, and causes the first PLMN to transition to ECM-CONNECTED_A and the second PLMN to transition to ECM-IDLE_B. 
     On the other hand, when the S1 release process is performed on the first core network  20 A in the “ECM-CONNECTED_A, ECM-IDLE_B” state, the wireless communication device  100  causes both the first and second PLMNs to transition to ECM-IDLE (ECM-IDLE_A, ECM-IDLE_B). 
     When performing the service request process on the second core network  20 B with both the first and second PLMNs in the ECM-IDLE (ECM-IDLE_A, ECM-IDLE_B) state, the wireless communication device  100  causes the first PLMN to transition to ECM-IDLE_A and the second PLMN to transition to ECM-CONNECTED_B. 
     When performing the S1 release process on the second core network  20 B in the “ECM-IDLE_A, ECM-CONNECTED_B” state, the wireless communication device  100  causes both the first and second PLMNs to transition to ECM-IDLE (ECM-IDLE_A, ECM-IDLE_B). 
     (RRC State Transition 2) 
     Subsequently, the state transition of the RRC in the wireless communication device  100  will be described.  FIG. 26  is a diagram illustrating an example of the state transition of the RRC in the wireless communication device  100 . The state management unit  149  of the wireless communication device  100  manages RRC-CONNECTED and RRC-IDLE as the active/standby state of the UE  1  for each PLMN. 
     In a case where both the first and second PLMNs are in RRC-IDLE (RRC-IDLE_A, RRC-IDLE_B), the wireless communication device  100  performs the RRC connection establishment process with the RAN connected to the first core network  20 A, and causes the first PLMN to transition to RRC-CONNECTED_A (maintains the state of RRC-IDLE_B for the second PLMN). 
     On the other hand, when the RRC connection release process is performed with the RAN connected to the first core network  20 A in the “RRC-CONNECTED_A, RRC-IDLE_B” state, the wireless communication device  100  causes the first PLMN to transition to RRC-IDLE (RRC-IDLE_A) (maintains the state of RRC-IDLE_B for the second PLMN). 
     When the RRC connection establishment process is performed with the RAN connected to the second core network  20 B with both the first and second PLMNs in the state of RRC-IDLE (RRC-IDLE_A, RRC-IDLE_B), the wireless communication device  100  causes the first PLMN to transition to RRC-IDLE_A and the second PLMN to transition to RRC-CONNECTED_B. 
     When the RRC connection release process is performed with the RAN connected to the second core network  20 B in the “RRC-IDLE_A, RRC-CONNECTED_B” state, the wireless communication device  100  causes both the first and second PLMNs to transition to RRC-IDLE (RRC-IDLE_A, RRC-IDLE_B). 
     (Registration Process) 
     Subsequently, the registration process performed by the wireless communication device  100  in a case where the management device  10  functions as the MME  3002  of LTE will be described. Here, a case where the wireless communication device  100  performs the second registration process will be described as an example.  FIG. 27  is a diagram illustrating an example of the registration process in LTE. 
     The wireless communication device  100  performs management in a state where the UE  1  is not registered in the first management device  10 A (EMM-DEREGISTERED_A), and the UE  1  is registered in the second management device  10 B (EMM-REGISTERED_B) (step S 1201 ). In this state, when there is an instruction from the upper layer, the wireless communication device  100  determines the switching of the network (including the network  20 L), that is, the switching of the PLMN to be registered (step S 1202 ). 
     The wireless communication device  100  transmits a Detach (registration deletion) request to the second management device  10 B in which the UE  1  is registered (step S 1203 ). The wireless communication device  100  causes both the first and second PLMNs to transition to the non-registration (EMM-DEREGISTERED_A, EMM-DEREGISTERED_B) state (step S 1204 ). 
     The wireless communication device  100  selects the first network  20 A as the network  20  to be switched (step S 1205 ). In other words, the wireless communication device  100  selects the first PLMN as the PLMN to be registered, and executes the registration selection process (step S 1206 ). 
     Here, the registration selection process is the same as the process illustrated in  FIG. 14  except that the IMSI request is transmitted instead of the SUPI request when the second PLMN ID is acquired, and thus description thereof is omitted. The wireless communication device  100  which selects the second registration process in the registration selection process executes the following second registration process. 
     First, the wireless communication device  100  transmits a second Attach request to the first management device  10 A (step S 1207 ). The second Attach request includes the second PLMN ID. 
     Here, when the GUTI allocated from the first PLMN to which the first management device  10 A belongs is available, the wireless communication device  100  transmits the second Attach request with the GUTI included therein. On the other hand, in a case where the allocated GUTI is not available, the wireless communication device  100  transmits the second Attach request with the GUTI allocated from another PLMN (for example, the second PLMN to which the second management device  10 B belongs), included therein. 
     Incidentally, in a case where the wireless communication device  100  does not have the available GUTI, the wireless communication device  100  transmits the second Attach request with the IMSI stored in the first SIM  30 A included therein. 
     The wireless communication device  100  may transmit, to the first management device  10 A, the second Attach request with the paging priority included therein. 
     The first management device  10 A which receives the second Attach request registers the UE  1  and registers the second PLMN as the visitor PLMN (step S 1208 ). 
     Here, in the case of not acquiring a permanent equipment identifier (PEI) which is identification information (UE identity) of the UE  1 , the first management device  10 A transmits an identity request to the wireless communication device  100  to acquire the PEI of the UE  1 . Incidentally, the first management device  10 A may acquire the IMSI instead of the PEI. 
     The first management device  10 A notifies the second management device  10 B belonging to the second PLMN that the second PLMN is registered as the visitor PLMN (step S 1209 ). Further, the first management device  10 A transmits a second Attach accept to the wireless communication device  100  to notify that the registration of the UE  1  is completed (step S 1210 ). 
     The wireless communication device  100  transitions the first PLMN to the registration state (EMM-REGISTERED_A) and the second PLMN to the non-registration (EMM-DEREGISTERED_B) state (step S 1211 ), and ends the second registration process. Here, the wireless communication device  100  may receive a notification indicating that the second PLMN is registered as the visitor PLMN via the second Attach accept message, and transition the first PLMN to the home PLMN registration state (EMM-REGISTERED_A) and the second PLMN to the visitor PLMN registration state (EMM-REGISTERED_R_B). Accordingly, the wireless communication device  100  monitors the first paging addressed to the IMSI stored in the first SIM  30 A and the second paging addressed to the IMSI stored in the second SIM  30 B for the network of the first PLMN to which the first management device  10 A belongs. 
     &lt;5.1.2. Application Example in Case where LTE and NR are Mixed&gt; 
     Next, a case where the first network  20 LA adopts LTE, and the second network  20 B adopts NR will be described. In this case, for example, it is assumed that the MME  3002 A belonging to the first network  20 LA and an AMF  1290 B belonging to the second network  20 B are connected to each other on the basis of the roaming agreement. 
     In this case, the first management device  10 A functions as the MME  3002 A, and the second management device  10 B functions as the AMF  1290 B. Further, the wireless communication device  100  manages the state transition of the EMM, the ECM, and the RCC for the first PLMN, and manages the state transition of the RM for the second PLMN. 
       FIG. 28  is a diagram illustrating an example of the registration process in a case where LTE and NR are mixed. In  FIG. 28 , it is assumed that the wireless communication device  100  selects switching from the second network  20 B to the first network  20 LA and performs the second registration process. 
     The wireless communication device  100  performs management in a state where the UE  1  is not registered in the first management device  10 A (EMM-DEREGISTERED_A), and the UE  1  is registered in the second management device  10 B (RM-REGISTERED_B) (step S 1301 ). In this state, when there is an instruction from the upper layer, the wireless communication device  100  determines the switching of the network  20 , that is, the switching of the PLMN to be registered (step S 1302 ). 
     The wireless communication device  100  transmits a Deregistration request to the second management device  10 B (step S 1303 ). The wireless communication device  100  causes both the first and second PLMNs to transition to the non-registration (EMM-DEREGISTERED_A, RM-DEREGISTERED_B) state (step S 1304 ). 
     The wireless communication device  100  selects the first network  20 LA as the network  20  to be switched (step S 1305 ). In other words, the wireless communication device  100  selects the first PLMN as the PLMN to be registered, and executes the registration selection process (step S 1306 ). 
     Here, it is assumed that the wireless communication device  100  selects the second registration process in the registration selection process. 
     In this case, the wireless communication device  100  transmits a second Attach request to the first management device  10 A (step S 1307 ). The second Attach request includes the second PLMN ID. 
     The first management device  10 A which receives the second Attach request registers the UE  1  and registers the second PLMN as the visitor PLMN (step S 1308 ). 
     The first management device  10 A notifies the second management device  10 B belonging to the second PLMN that the second PLMN is registered as the visitor PLMN (step S 1309 ). Further, the first management device  10 A transmits a second Attach accept to the wireless communication device  100  to notify that the registration of the UE  1  is completed (step S 1310 ). 
     The wireless communication device  100  transitions the first PLMN to the registration state (EMM-REGISTERED_A) and the second PLMN to the non-registration (RM-DEREGISTERED_B) state (step S 1311 ), and ends the second registration process. Here, the wireless communication device  100  may receive a notification indicating that the second PLMN is registered as the visitor PLMN via the second Attach accept message, and transition the first PLMN to the home PLMN registration state (EMM-REGISTERED_A) and the second PLMN to the visitor PLMN registration state (RM-REGISTERED_R_B). Accordingly, the wireless communication device  100  monitors the first paging addressed to the IMSI stored in the first SIM  30 A and the second paging addressed to the SUPI stored in the second SIM  30 B for the network of the first PLMN to which the first management device  10 A belongs. 
     As described above, even in a case where different radio access technologies such as LTE and NR are mixed, the wireless communication device  100  can switch between two SIMs to perform communication. 
     &lt;5.2. Application Example Regarding Wireless Communication Device&gt; 
     First Application Example 
       FIG. 29  is a block diagram illustrating an example of a schematic configuration of a smartphone  9000  to which the technology according to the present disclosure can be applied. The smartphone  9000  includes a processor  9010 , a memory  9020 , a storage  9030 , an external connection interface  9040 , a camera  9060 , a sensor  9070 , a microphone  9080 , an input device  9090 , a display device  9100 , a speaker  9110 , a wireless communication interface  9120 , an antenna  9160 , a bus  9170 , a battery  9180 , and an auxiliary controller  9190 . 
     The processor  9010  may be, for example, a CPU or a system on chip (SoC), and controls the functions of an application layer and other layers of the smartphone  9000 . The memory  9020  includes a RAM and a ROM, and stores a program executed by the processor  9010  and data. The storage  9030  may include a storage medium such as a semiconductor memory and a hard disk. The external connection interface  9040  is an interface for connecting an externally attached device such as memory cards and universal serial bus (USB) devices to the smartphone  9000 . 
     The camera  9060  includes, for example, an image sensor such as charge coupled devices (CCDs) and complementary metal oxide semiconductor (CMOS), and generates a captured image. The sensor  9070  may include a sensor group including, for example, a positioning sensor, a gyro sensor, a geomagnetic sensor, an acceleration sensor, and the like. The microphone  9080  converts a sound that is input into the smartphone  9000  to an audio signal. The input device  9090  includes, for example, a touch sensor which detects that a screen of the display device  9100  is touched, a key pad, a keyboard, a button, a switch, or the like, and accepts an operation or an information input from a user. The display device  9100  includes a screen such as liquid crystal displays (LCDs) and organic light emitting diode (OLED) displays, and displays an output image of the smartphone  9000 . The speaker  9110  converts the audio signal that is output from the smartphone  9000  to a sound. 
     The wireless communication interface  9120  supports a cellular communication system such as NR or LTE and executes wireless communication. The wireless communication interface  9120  may typically include a BB processor  9130 , an RF circuit  9140 , and the like. The BB processor  9130  may, for example, perform encoding/decoding, modulation/demodulation, multiplexing/demultiplexing, and the like, and executes a variety of types of signal processing for wireless communication. On the other hand, the RF circuit  9140  may include a mixer, a filter, an amplifier, and the like, and transmits and receives a wireless signal via the antenna  9160 . The wireless communication interface  9120  may be a one-chip module in which the BB processor  9130  and the RF circuit  9140  are integrated. 
     The wireless communication interface  9120  may support other types of wireless communication system such as a short range wireless communication system, a near field communication system, and a wireless local area network (LAN) system in addition to the cellular communication system, and in this case, the wireless communication interface  9120  may include the BB processor  9130  and the RF circuit  9140  for each wireless communication system. Here, the short range wireless communication system may include device to device (D2D) communication called sidelink. 
     The antenna  9160  includes one or more antenna elements (for example, a plurality of antenna elements configuring a MIMO antenna) and is used for transmission and reception of the wireless signal by the wireless communication interface  9120 . 
     The bus  9170  connects the processor  9010 , the memory  9020 , the storage  9030 , the external connection interface  9040 , the camera  9060 , the sensor  9070 , the microphone  9080 , the input device  9090 , the display device  9100 , the speaker  9110 , the wireless communication interface  9120 , and the auxiliary controller  9190  to each other. The battery  9180  supplies electric power to each block of the smartphone  9000  illustrated in  FIG. 29  via a feeder line that is partially indicated by a broken line in the drawing. The auxiliary controller  9190 , for example, operates a minimally necessary function of the smartphone  9000  in a sleep mode. 
     In the smartphone  9000  illustrated in  FIG. 29 , one or more components included in the control unit  140  described with reference to  FIG. 7  may be implemented in the wireless communication interface  9120 . Alternatively, at least some of these components may be implemented in the processor  9010  or the auxiliary controller  9190 . As an example, the smartphone  9000  may be mounted with a module including a part (for example, the BB processor  9130 ) or all of the wireless communication interface  9120 , the processor  9010 , and/or the auxiliary controller  9190 , and the module may be implemented with one or more of the components. In this case, the module may store a program for causing the processor to function as the one or more components (in other words, a program for causing the processor to execute the operations of the one or more components) and execute the program. As another example, a program for causing the processor to function as the one or more components may be installed in the smartphone  9000 , and the wireless communication interface  9120  (for example, the BB processor  9130 ), the processor  9010 , and/or the auxiliary controller  9190  may execute the program. As described above, the smartphone  9000  or the module may be provided as a device including the one or more components, and a program for causing the processor to function as the one or more components may be provided. Further, a readable recording medium on which the above-described program is recorded may be provided. 
     In the smartphone  9000  illustrated in  FIG. 29 , for example, the communication unit  120  described with reference to  FIG. 7  may be implemented in the wireless communication interface  9120  (for example, the RF circuit  9140 ). Further, the antenna unit  110  may be implemented in the antenna  9160 . Further, the storage unit  130  may be implemented in the memory  9020 . 
     Second Application Example 
       FIG. 30  is a block diagram illustrating an example of a schematic configuration of a car navigation device  9200  to which the technology according to the present disclosure can be applied. The car navigation device  9200  includes a processor  9210 , a memory  9220 , a global positioning system (GPS) module  9240 , a sensor  9250 , a data interface  9260 , a content player  9270 , a storage medium interface  9280 , an input device  9290 , a display device  9300 , a speaker  9310 , a wireless communication interface  9330 , an antenna  9370 , and a battery  9380 . 
     The processor  9210  may be, for example, a CPU or an SoC, and controls the navigation function and the other functions of the car navigation device  9200 . The memory  9220  includes a RAM and a ROM, and stores a program executed by the processor  9210  and data. 
     The GPS module  9240  uses a GPS signal received from a GPS satellite to measure the position (for example, latitude, longitude, and altitude) of the car navigation device  9200 . The sensor  9250  may include a sensor group including, for example, a gyro sensor, a geomagnetic sensor, and a barometric sensor. The data interface  9260  is, for example, connected to an in-vehicle network  9410  via a terminal that is not illustrated, and acquires data such as vehicle speed data generated on the vehicle side. 
     The content player  9270  reproduces content stored in a storage medium (for example, CD or DVD) inserted into the storage medium interface  9280 . The input device  9290  includes, for example, a touch sensor which detects that a screen of the display device  9300  is touched, a button, a switch, or the like, and accepts operation or information input from a user. The display device  9300  includes a screen such as LCDs and OLED displays, and displays an image of the navigation function or the reproduced content. The speaker  9310  outputs a sound of the navigation function or the reproduced content. 
     The wireless communication interface  9330  supports a cellular communication system such as NR or LTE and executes wireless communication. The wireless communication interface  9330  may typically include a BB processor  9340 , an RF circuit  9350 , and the like. The BB processor  9340  may, for example, perform encoding/decoding, modulation/demodulation, multiplexing/demultiplexing, and the like, and executes a variety of types of signal processing for wireless communication. On the other hand, the RF circuit  9350  may include a mixer, a filter, an amplifier, and the like, and transmits and receives a wireless signal via the antenna  9370 . The wireless communication interface  9330  may be a one-chip module in which the BB processor  9340  and the RF circuit  9350  are integrated. 
     The wireless communication interface  9330  may support other types of wireless communication system such as a short range wireless communication system, a near field communication system, and a wireless LAN system in addition to the cellular communication system, and in this case, the wireless communication interface  9330  may include the BB processor  9340  and the RF circuit  9350  for each wireless communication system. Here, the short range wireless communication system may include device to device (D2D) communication called sidelink. 
     The antenna  9370  includes one or more antenna elements (for example, a plurality of antenna elements configuring a MIMO antenna) and is used for transmission and reception of the wireless signal by the wireless communication interface  9330 . 
     The battery  9380  supplies electric power to each block of the car navigation device  9200  illustrated in  FIG. 30  via a feeder line that is partially indicated by a broken line in the drawing. Further, the battery  9380  accumulates the electric power supplied from the vehicle. 
     In the car navigation device  9200  illustrated in  FIG. 30 , one or more components included in the control unit  140  described with reference to  FIG. 7  may be implemented in the wireless communication interface  9330 . Alternatively, at least some of these components may be implemented in the processor  9210 . As an example, the car navigation device  9200  may be mounted with a module including a part (for example, the BB processor  9340 ) or all of the wireless communication interface  9330  and/or the processor  9210 , and the module may be implemented with one or more of the components. In this case, the module may store a program for causing the processor to function as the one or more components (in other words, a program for causing the processor to execute the operations of the one or more components) and execute the program. As another example, a program for causing the processor to function as the one or more components may be installed in the car navigation device  9200 , and the wireless communication interface  9330  (for example, the BB processor  9340 ) and/or the processor  9210  may execute the program. As described above, the car navigation device  9200  or the module may be provided as a device including the one or more components, and a program for causing the processor to function as the one or more components may be provided. Further, a readable recording medium on which the above-described program is recorded may be provided. 
     In the car navigation device  9200  illustrated in  FIG. 30 , for example, the communication unit  120  described with reference to  FIG. 7  may be implemented in the wireless communication interface  9330  (for example, the RF circuit  9350 ). Further, the antenna unit  110  may be implemented in the antenna  9370 . Further, the storage unit  130  may be implemented in the memory  9220 . 
     The technology of the present disclosure may also be realized as an in-vehicle system (or a vehicle)  9400  including one or more blocks of the above-described car navigation device  9200 , the in-vehicle network  9410 , and a vehicle module  9420 . The vehicle module  9420  generates vehicle data such as vehicle speed, engine speed, and trouble information, and outputs the generated data to the in-vehicle network  9410 . 
     &lt;5.3. Other Application Examples&gt; 
     In the embodiment described above, the wireless communication device  100  performs communication with switching between the first and second networks  20 A and  20 B operated by the first and second MNOs, but the present invention is not limited thereto. One of the networks in which the wireless communication device  100  performs communication may be, for example, a network managed and operated by a service provider other than the MNO. Examples of the network include a private network, a non-public network, and a neutral host network. Further, examples of the service provider which operates such a network include an owner of a factory, a hospital which uses an operating room, and a retailer which operates a store. 
     In the embodiment described above, the first and second subscriber modules are the SIM  30  mounted on the UE  1 . However, the SIM  30  may be any module which can identify the subscriber of the service provided by the MNO, and may be, for example, a universal subscriber identity module (USIM) used in LTE or a next generation (NextGen) USIM for 5G. 
     The SIM  30  is not limited to a removable SIM card, and may be, for example, an embedded SIM (eSIM) or an integrated SIM configured inside the SoC. Further, the eSIM and the integrated SIM may be downloadable SIMs in which held contents can be written or updated via an external device or a wired or wireless network. The downloadable SIM may be called, for example, a software SIM or a software SIM. 
     6. MODIFICATION 
     The control device which controls the management device  10  and the wireless communication device  100  of this embodiment may be realized by a dedicated computer system or may be realized by a general-purpose computer system. 
     For example, a program for executing the above-described operation is stored and distributed in a computer-readable recording medium such as an optical disk, a semiconductor memory, a magnetic tape, a flexible disk, or a hard disk. Then, for example, the control device is configured by installing the program in a computer and executing the above-described processing. At this time, the control device may be an external device (for example, a personal computer) of the management device  10  or the wireless communication device  100 . Further, the control device may be the management device  10  or an internal device (for example, the control unit  13  or the control unit  140 ) of the wireless communication device  100 . 
     The communication program may be stored in a disk device included in a server device on a network such as the Internet so as to be downloaded to a computer, or the like. Further, the above-described functions may be realized by cooperation between an operating system (OS) and application software. In this case, a part other than the OS may be stored and distributed in a medium, and the part other than the OS may be stored in the server device, so as to be downloaded to a computer, or the like. 
     Among the processing described in the above embodiment, all or part of the processing described as being automatically performed may be manually performed, or all or part of the processing described as being manually performed may be automatically performed by a known method. In addition, the processing procedures, specific names, information including various data and parameters described in the above-described specification and drawings may be arbitrarily changed unless otherwise specified. For example, the various types of information illustrated in each drawing are not limited to the illustrated information. 
     Each component of each device illustrated in the drawings is functionally conceptual, and does not necessarily have to be physically configured as illustrated. That is, the specific form of distribution and integration of each device is not limited to the illustrated one, and all or part of the device may be configured to be functionally or physically distributed and integrated in arbitrary units according to various loads, use conditions, and the like. 
     The above-described embodiment can be appropriately combined in an area in which the processing contents do not contradict each other. 
     7. CONCLUSION 
     As described above, according to an embodiment of the present disclosure, a wireless communication device (for example, the wireless communication device  100 ) includes a control unit (for example, the control unit  140 ). The control unit (control unit  140 ) acquires a first PLMN list (for example, the first PLMN list  40 ) on the basis of information stored in a first subscriber identity module (for example, the first SIM  30 A). The control unit (control unit  140 ) selects a home PLMN from the first PLMN list (first PLMN list  40 ). The control unit (control unit  140 ) acquires a second PLMN ID on the basis of information stored in a second subscriber identity module (for example, the second SIM  30 B). In a case where the second PLMN ID is not included in the first PLMN list (first PLMN list  40 ), the control unit (control unit  140 ) performs a first registration request (for example, the Registration request) to a first management device (for example, the first management device  10 A) which belongs to the home PLMN and manages registration of the wireless communication device (wireless communication device  100 ). In a case where the second PLMN ID is included in the first PLMN list (first PLMN list  40 ), the control unit (control unit  140 ) performs, to the first management device (first management device  10 A), a second registration request (for example, the second Registration request) with information regarding a second PLMN included therein. Accordingly, the first management device can manage the second PLMN as a visitor PLMN in a case where the second PLMN ID is included in the first PLMN list. In this case, the wireless communication device may receive paging not only from the first PLMN but also from the second PLMN in the case of being registered in the first management device. 
     Although each of the embodiments of the present disclosure has been described above, the technical scope of the present disclosure is not limited to each of the above-described embodiments as it is, and various modifications may be made without departing from the gist of the present disclosure. Further, the components may be combined suitably over different embodiments and the modification. 
     The effects in each embodiment described in this specification are merely examples and are not limited, and other effects may be present. 
     Incidentally, this technology may also be configured as below. 
     (1) 
     A wireless communication device comprising: 
     a control unit that acquires a first PLMN list on a basis of information stored in a first subscriber identity module, 
     selects a home PLMN from the first PLMN list, 
     acquires a second PLMN ID on a basis of information stored in a second subscriber identity module, 
     perform a first registration request to a first management device which belongs to the home PLMN and manages registration of the wireless communication device in a case where the second PLMN ID is not included in the first PLMN list, and 
     performs, to the first management device, a second registration request with information regarding the second PLMN included in the second registration request in a case where the second PLMN ID is included in the first PLMN list. 
     (2) 
     The wireless communication device according to (1), wherein 
     the control unit acquires an EHPLMN list and a forbidden PLMN list from the first subscriber identity module, and 
     sets a list obtained by removing the forbidden PLMN list from the EHPLMN list as the first PLMN list. 
     (3) 
     The wireless communication device according to (1) or (2), wherein 
     the control unit performs a registration deletion request to a second management device which belongs to the second PLMN and manages registration of the wireless communication device, and then performs the first or second registration request to the first management device. 
     (4) 
     The wireless communication device according to (3), wherein 
     the control unit performs the first or second registration request to the first management device in a case where switching from the second management device to the first management device is determined. 
     (5) 
     The wireless communication device according to (3) or (4), wherein 
     the control unit performs the first or second registration request to the first management device in a case where a switching instruction to the first management device from the second management device is received. 
     (6) 
     The wireless communication device according to (5), wherein 
     the switching instruction includes a timer period, and 
     the control unit requests the first management device to perform registration during the timer period. 
     (7) 
     The wireless communication device according to (6), wherein 
     in a case of requesting the first management device to perform registration during the timer period, the control unit transmits a registration request signal including a registration period in which the registration is performed. 
     (8) 
     The wireless communication device according to (6) or (7), wherein 
     the control unit requests registration in the first management device without requesting deletion of registration in the second management device during the timer period. 
     (9) 
     The wireless communication device according to (8), in which 
     the control unit manages a registration/non-registration state in the first and second management devices, and 
     in a case where the timer period or the registration period ends, causes a registration state in the first management device to transition to a non-registration state. 
     (10) 
     A communication control method comprising: 
     acquiring a first PLMN list on a basis of information stored in a first subscriber identity module; 
     selecting a home PLMN from the first PLMN list; 
     acquiring a second PLMN ID on a basis of information stored in a second subscriber identity module; 
     performing a first registration request to a first management device which belongs to the home PLMN and manages mobility in a case where the second PLMN ID is not included in the first PLMN list, and 
     performing, to the first management device, a second registration request with information regarding the second PLMN included in the second registration request in a case where the second PLMN ID is included in the first PLMN list. 
     (11) 
     A management device which belongs to a first PLMN and manages registration of a wireless communication device, the device including: 
     a control unit that receives a registration request including a second PLMN ID from the wireless communication device, 
     registers the wireless communication device according to the registration request, and 
     notifies a second management device belonging to the second PLMN of the registration of the wireless communication device. 
     (12) 
     The management device according to (11), in which 
     the control unit receives a notification regarding paging addressed to the wireless communication device from the second PLMN via the second management device. 
     (13) 
     The management device according to (12), in which 
     the control unit transmits a switching instruction for switching a registration destination from the first PLMN to the second PLMN to the wireless communication device in a case of receiving the notification regarding the paging. 
     (14) 
     The management device according to (13), in which 
     the switching instruction includes a timer period, and the control unit transmits paging from the first PLMN after waiting for an end of the timer period. 
     (15) 
     The management device according to (14), in which 
     the notification regarding the paging includes information regarding a size of data to be transmitted by paging, and 
     the control unit transmits the switching instruction including the timer period in a case where the size is equal to or less than a threshold. 
     (16) 
     The management device according to (12), in which 
     the control unit transmits paging from the second PLMN to the wireless communication device according to the received notification regarding the paging. 
     (17) 
     The management device according to (16), in which 
     the registration request includes a paging priority of the first PLMN or the second PLMN, and 
     the control unit transmits paging from the first or second PLMN according to the paging priority in a case of receiving paging from the first PLMN and the notification regarding the paging from the second PLMN via the second management device. 
     (18) 
     A management device which belongs to a second PLMN, the device including: 
     a control unit that receives a notification regarding registration of a wireless communication device from a first management device belonging to a first PLMN, and 
     transmits a notification regarding paging to the first management device in a case where a paging request addressed to the wireless communication device is received from the second PLMN. 
     (19) 
     The management device according to (18), in which 
     the notification regarding the paging is a paging request addressed to the wireless communication device. 
     (20) 
     The management device according to (19), in which 
     the notification regarding the paging is a switching request for switching a registration destination of the wireless communication device from the first PLMN to the second PLMN. 
     (21) 
     The management device according to any one of (18) to (20), in which 
     the notification regarding the paging includes information regarding a size of data to be transmitted by the paging. 
     (22) 
     The management device according to (21), in which 
     the control unit registers the wireless communication device in a case where a registration request is received from the wireless communication device after transmission of the switching request. 
     (23) 
     The management device according to (22), in which 
     the registration request includes a registration period, and 
     the control unit manages the wireless communication device as a registration state during the registration period, and manages the wireless communication device to transition from the registration state to a non-registration state when the registration period ends. 
     (24) 
     A management method by a management device which belongs to a first PLMN and manages registration of a wireless communication device, the method including: 
     receiving a registration request including a second PLMN ID from the wireless communication device; 
     registering the wireless communication device according to the registration request; and 
     notifying a second management device belonging to the second PLMN of the registration of the wireless communication device. 
     (25) 
     A management method by a management device which belongs to a second PLMN, the method including: 
     receiving a notification regarding registration of a wireless communication device from a first management device belonging to a first PLMN; and 
     transmitting a notification regarding paging to the first management device in a case where a paging request addressed to the wireless communication device is received from the second PLMN. 
     REFERENCE SIGNS LIST 
     
         
         
           
               1  UE 
               10  MANAGEMENT DEVICE 
               11  NETWORK COMMUNICATION UNIT 
               12 ,  130  STORAGE UNIT 
               13 ,  140  CONTROL UNIT 
               20  NETWORK 
               30  SIM 
               100  WIRELESS COMMUNICATION DEVICE 
               120  COMMUNICATION UNIT 
               131 ,  149  STATE MANAGEMENT UNIT 
               141  SWITCHING CONTROL UNIT 
               142 ,  144  ACQUISITION UNIT 
               143  SELECTION UNIT 
               145  DETERMINATION UNIT 
               146  REGISTRATION SELECTION UNIT 
               147  REGISTRATION PROCESSING UNIT 
               148  DEREGISTRATION PROCESSING UNIT