COMMUNICATION DEVICE, BASE STATION, AND COMMUNICATION METHOD

Abstract

To provide a user device, a base station, and a communication control method that can facilitate monitoring of paging of a second network while maintaining a connection state with a first network in a radio resource control (RRC) layer.SOLUTION: In a mobile communication system, a user device 100 that communicates with a plurality of networks 200A and 200B using a plurality of subscriber identification modules communicates with a base station 210A of the first network 200A included in the plurality of networks 200A and 200B, determines whether the second network 200B included in the plurality of networks 200A and 200B is synchronized with the first network 200A, and transmits a radio resource control RRC message containing an information element indicating whether the second network 200B is synchronized with the first network 200A to the base station 210A.SELECTED DRAWING: Figure 6

Description

[Technical field]

[0001] The present invention relates to a user equipment, a base station, and a communication control method for use in a mobile communication system. [Background technology]

[0002] Release 17 of the 3GPP (3rd Generation Partnership Project), a standardization project for mobile communication systems, has launched a work item to define a function that enables user equipment equipped with multiple subscriber identity modules to perform data communications while present in the networks of multiple telecommunications carriers.

[0003] At present, there is no provision in the standard specifications for a mechanism for a user device in the range of multiple networks to receive paging (i.e., incoming calls), and it is dependent on the implementation of the user device. However, if there is an incoming call from one network (hereinafter, "second network") while communicating with another network (hereinafter, "first network"), the user device will miss the incoming call. For this reason, a method of receiving incoming calls from multiple networks in cooperation with each network is being considered in the 3GPP standardization forum (see, for example, Non-Patent Documents 1 to 4).

[0004] Non-Patent Documents 1 to 4 describe a method in which, in a case where a user device equipped with multiple subscriber identity modules has only one receiving unit (RX: Receiver), the first network sets an interruption timing for the user device to temporarily interrupt communication with the first network in order for the user device to monitor paging of the second network while maintaining a connection with the first network. Such an interruption timing is sometimes called a "gap." [Prior art documents] [Non-patent literature]

[0005] [Non-Patent Document 1] 3GPP contribution: R2-2009265, “Scenarios and Impact analysis for Switching Notification” [Non-Patent Document 2] 3GPP contribution: R2-2009557, “Switching between two links for Multi-SIM” [Non-Patent Document 3] 3GPP contribution: R2-2010350, “Discussion on switching mechanism for multi-SIM” [Non-Patent Document 4] 3GPP contribution: R2-2100475, “Discussion on Switching Notification Procedure” Summary of the Invention [Problem to be solved by the invention]

[0006] When the first network and the second network are asynchronous, i.e., when the system frame numbers (SFNs) and / or frame timings used by the two networks are not aligned, the first network cannot properly set the suspend timing for the user equipment, which makes it difficult for the user equipment to monitor the paging of the second network while maintaining a connection state (RRC connected state) with the first network in a radio resource control (RRC) layer.

[0007] Therefore, an object of the present invention is to provide a user equipment, a base station, and a communication control method that facilitate monitoring paging of a second network while maintaining a connection state in the RRC layer with a first network. [Means for solving the problem]

[0008] A user device according to a first aspect is a user device (100) that communicates with a plurality of networks (200A, 200B) using a plurality of subscriber identity modules (111, 112), and includes a communication unit (120) that communicates with a base station (210A) of a first network (200A) included in the plurality of networks (200A, 200B), and a control unit (130) that determines whether a second network (200B) included in the plurality of networks (200A, 200B) is synchronized with the first network (200A). The communication unit (120) transmits a radio resource control (RRC) message including an information element indicating whether the second network (200B) is synchronized with the first network (200A) to the base station (210A).

[0009] A base station according to a second aspect is a base station (210A) of a first network (200A) included in the multiple networks (200A, 200B) in a mobile communication system (1) in which a user device (100) communicates with multiple networks (200A, 200B) using multiple subscriber identity modules (111, 112), and includes a communication unit (212) that receives a radio resource control (RRC) message from the user device (100) including an information element indicating whether a second network (200B) included in the multiple networks (200A, 200B) is synchronized with the first network (200A), and a control unit (214) that acquires the information element included in the RRC message.

[0010] A communication control method according to a third aspect is a communication control method executed by a user device (100) that communicates with multiple networks (200A, 200B) using multiple subscriber identity modules (111, 112), and includes the steps of communicating with a base station (210A) of a first network (200A) included in the multiple networks (200A, 200B), determining whether a second network (200B) included in the multiple networks (200A, 200B) is synchronized with the first network (200A), and transmitting a radio resource control (RRC) message to the base station (210A) including an information element indicating whether the second network (200B) is synchronized with the first network (200A). Effect of the Invention

[0011] According to one aspect of the present invention, it is possible to provide a user equipment, a base station, and a communication control method that facilitate monitoring paging of a second network while maintaining a connection state in the RRC layer with a first network. [Brief description of the drawings]

[0012] [Figure 1] 1 is a diagram showing a configuration of a mobile communication system according to a first and second embodiment. [Diagram 2] FIG. 2 is a diagram illustrating an example of the configuration of a protocol stack in the mobile communication system according to the first and second embodiments. [Diagram 3] FIG. 2 is a diagram illustrating an example of the configuration of a UE according to the first and second embodiments. [Figure 4] FIG. 2 is a diagram illustrating an example of the configuration of a base station of a first network according to the first and second embodiments. [Diagram 5] A diagram showing an example of the operation of a UE for which an interruption timing is set by a base station of a first network according to the first and second embodiments. [Figure 6] FIG. 2 is a diagram showing an example of operation of the mobile communication system according to the first embodiment. [Figure 7] FIG. 11 is a diagram showing an example of the operation of the mobile communication system according to the second embodiment. [Figure 8] FIG. 13 is a diagram showing a modification of the second embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] A mobile communication system according to an embodiment will be described with reference to the drawings. In the description of the drawings, the same or similar parts are denoted by the same or similar reference numerals.

[0014] [First embodiment] The first embodiment will be described with reference to FIGS.

[0015] (System Configuration) A configuration of a mobile communication system 1 according to the first embodiment will be described with reference to Fig. 1. In the following, an example in which the mobile communication system 1 is a 3GPP standard fifth generation system (5G / NR: New Radio) will be mainly described, but a fourth generation system (4G / LTE: Long Term Evolution) system and / or a sixth generation system may be at least partially applied to the mobile communication system 1.

[0016] As shown in FIG. 1, a mobile communication system 1 according to the first embodiment includes a user equipment (UE) 100, a first network 200A, and a second network 200B.

[0017] The UE 100 is a mobile wireless communication device. The UE 100 may be any device used by a user, and may be, for example, a mobile phone terminal (including a smartphone), a tablet terminal, a notebook PC, a communication module (including a communication card or a chipset), a sensor or a device provided in a sensor, a vehicle or a device provided in a vehicle (Vehicle UE), or an aircraft or a device provided in an aircraft (Aerial UE).

[0018] The UE 100 is a multi-SIM device that supports multiple subscriber identity modules (SIMs). In the following, an example in which the UE 100 supports two SIMs will be mainly described, but the UE 100 may support three or more SIMs. "Supporting multiple SIMs" means that the UE 100 has the ability to handle multiple SIMs, and the UE 100 does not necessarily have to be equipped with multiple SIMs. Such a UE 100 may be called a "UE that supports multiple SIMs." The SIM is not limited to a card-type SIM (a so-called SIM card), and may be an embedded SIM (a so-called eSIM) that is previously embedded in the UE 100. The SIM may be called a Universal Subscriber Identity Module (USIM).

[0019] The first network 200A is a network associated with one SIM of the UE 100. The second network 200B is a network associated with the other SIM of the UE 100. The UE 100 performs location registration to the first network 200A using one SIM, and performs location registration to the second network 200B using the other SIM. That is, the UE 100 is present in each of the first network 200A and the second network 200B. The first network 200A and the second network 200B may be networks of different telecommunications carriers. However, the first network 200A and the second network 200B may be networks of the same telecommunications carrier. The first network 200A and the second network 200B may be assigned different PLMN (Public Land Mobile Network) IDs.

[0020] The first network 200A includes a base station 210A constituting a radio access network, and a core network 220A. The core network 220A includes a mobility management device 221A and a gateway device 222A. Similarly, the second network 200B includes a base station 210B constituting a radio access network, and a core network 220B. The core network 220B includes a mobility management device 221B and a gateway device 222B. In the following, when the base stations 210A and 200B are not distinguished, they are simply called the base station 210, when the mobility management devices 221A and 221B are not distinguished, they are simply called the mobility management device 221, and when the gateway devices 222A and 222B are not distinguished, they are simply called the gateway device 222.

[0021] The base station 210 is a wireless communication device that performs wireless communication with the UE 100. The base station 210 manages one or more cells. The base station 210 performs wireless communication with the UE 100 that has established a connection with the base station 210 in a radio resource control (RRC) layer with the base station 210. The base station 210 has a radio resource management (RRM) function, a routing function for user data (hereinafter simply referred to as "data"), a measurement control function for mobility control and scheduling, and the like. "Cell" is used as a term indicating the smallest unit of a wireless communication area. "Cell" is also used as a term indicating a function or resource for performing wireless communication with the UE 100. One cell belongs to one carrier frequency. FIG. 1 shows an example in which the base station 210A manages a cell C1, and the base station 210B manages a cell C2. The UE 100 is located in an overlapping area of ​​the cells C1 and C2.

[0022] A frame used in wireless communication between UE 100 and base station 210 is, for example, 10 ms, and a system frame number (SFN) is assigned to each frame. Each frame is divided into subframes of, for example, 1 ms, and each subframe is composed of multiple OFDM symbols.

[0023] The base station 210 may be a gNB, which is a 5G / NR base station, or an eNB, which is a 4G / LTE base station. In the following, an example in which the base station 210 is a gNB will be mainly described. The base station 210 may be functionally divided into a CU (Central Unit) and a DU (Distributed Unit). The base station 210 may be a relay node such as an IAB (Integrated Access and Backhaul) node.

[0024] The mobility management device 221 is a device corresponding to the control plane, and is a device that performs various mobility management for the UE 100. The mobility management device 221 communicates with the UE 100 using NAS (Non-Access Stratum) signaling, and manages information of a tracking area in which the UE 100 is located. The mobility management device 221 performs paging through the base station 210 to notify the UE 100 of an incoming call. The mobility management device 221 may be an AMF (Access and Mobility Management Function) of 5G / NR, or an MME (Mobility Management Entity) of 4G / LTE.

[0025] The gateway device 222 is a device corresponding to the user plane and controls the transfer of data of the UE 100. The gateway device 222 may be a User Plane Function (UPF) of 5G / NR or a Serving Gateway (S-GW) of 4G / LTE.

[0026] In the mobile communication system 1 configured as above, a scenario is assumed in which the UE 100 having only one receiving unit (RX: Receiver) performs data communication while existing in the first network 200A and the second network 200B. If the UE 100 receives a paging from the second network 200B while communicating with the first network 200A, the UE 100 cannot receive the paging and misses the incoming call.

[0027] In order for the UE 100 to monitor paging of the second network 200B while maintaining the RRC connection with the first network 200A, the first network 200A sets an interruption timing for the UE 100, which allows the UE 100 to temporarily interrupt communication with the first network 200A. However, if the first network 200A and the second network 200B are asynchronous, i.e., the SFN and / or frame timing used by both networks are not aligned, it is difficult for the first network 200A to appropriately set the interruption timing for the UE 100. In particular, if the first network 200A and the second network 200B are operated by different communication carriers, the first network 200A and the second network 200B may be asynchronous.

[0028] (Example of protocol stack configuration) An example of the configuration of a protocol stack in the mobile communication system 1 will be described with reference to FIG.

[0029] As shown in FIG. 2, the protocol for the wireless section between UE 100 and base station 210 includes a physical (PHY) layer, a Medium Access Control (MAC) layer, a Radio Link Control (RLC) layer, a Packet Data Convergence Protocol (PDCP) layer, and an RRC layer.

[0030] The PHY layer performs encoding / decoding, modulation / demodulation, antenna mapping / demapping, and resource mapping / demapping. Data and control information are transmitted between the PHY layer of the UE 100 and the PHY layer of the base station 210 via a physical channel.

[0031] The MAC layer performs data priority control, retransmission processing using hybrid ARQ (HARQ), random access procedures, etc. Data and control information are transmitted between the MAC layer of the UE 100 and the MAC layer of the base station 210 via a transport channel. The MAC layer of the base station 210 includes a scheduler. The scheduler determines the uplink and downlink transport format (transport block size, modulation and coding scheme (MCS)) and the resources to be allocated to the UE 100.

[0032] The RLC layer transmits data to the RLC layer on the receiving side by using the functions of the MAC layer and the PHY layer. Data and control information are transmitted between the RLC layer of the UE 100 and the RLC layer of the base station 210 via logical channels.

[0033] The PDCP layer performs header compression / decompression and encryption / decryption.

[0034] A Service Data Adaptation Protocol (SDAP) layer may be provided above the PDCP layer. The Service Data Adaptation Protocol (SDAP) layer maps IP flows, which are units for QoS control by the core network, to radio bearers, which are units for QoS control by the access stratum (AS).

[0035] The RRC layer controls logical channels, transport channels, and physical channels according to the establishment, re-establishment, and release of radio bearers. RRC signaling for various settings is transmitted between the RRC layer of the UE 100 and the RRC layer of the base station 210. When there is an RRC connection between the RRC of the UE 100 and the RRC of the base station 210, the UE 100 is in an RRC connected state. When there is no RRC connection between the RRC of the UE 100 and the RRC of the base station 210, the UE 100 is in an RRC idle state. When the RRC connection between the RRC of the UE 100 and the RRC of the base station 210 is suspended, the UE 100 is in an RRC inactive state.

[0036] The NAS layer, which is located above the RRC layer, performs session management and mobility management for the UE 100. NAS signaling is transmitted between the NAS layer of the UE 100 and the NAS layer of the mobility management device 221.

[0037] In addition, the UE 100 has an application layer and the like in addition to the protocol of the radio interface.

[0038] (Example of UE configuration) With reference to FIG. 3, an example of the configuration of UE 100 will be described.

[0039] 3, the UE 100 includes an antenna 101, an SIM 111, an SIM 112, a communication unit 120, and a control unit 130. The antenna 101 may be provided outside the UE 100. The SIM 111 and the SIM 112 are SIM cards or eSIMs.

[0040] The SIM 111 stores subscriber information and setting information necessary for the UE 100 to communicate with the first network 200A. The SIM 111 stores identification information of the UE 100 in the first network 200A, such as a telephone number and an International Mobile Subscriber Identity (IMSI).

[0041] The SIM 112 stores subscriber information and setting information necessary for the UE 100 to communicate with the second network 200B. The SIM 112 stores identification information of the UE 100 in the second network 200B, such as a telephone number and an IMSI.

[0042] The communication unit 120 performs wireless communication with the first network 200A and wireless communication with the second network 200B via the antenna 101 under the control of the control unit 130. The communication unit 120 may have only one receiving unit (RX: Receiver) 121. In this case, the communication unit 120 cannot simultaneously receive from the first network 200A and the second network 200B. The communication unit 120 may have only one transmitting unit (TX: Transmitter) 122. However, the communication unit 120 may have multiple transmitting units 122. The receiving unit 121 converts a radio signal received by the antenna 101 into a received signal that is a baseband signal, performs signal processing on the received signal, and outputs the signal to the control unit 130. The transmitting unit 122 performs signal processing on a transmission signal that is a baseband signal output by the control unit 130, converts the signal into a radio signal, and transmits the radio signal from the antenna 101.

[0043] The control unit 130 controls the communication unit 120 and performs various controls in the UE 100. The control unit 130 controls communication with the first network 200A using the SIM 111 and controls communication with the second network 200B using the SIM 112. The control unit 130 includes at least one processor and at least one memory. The memory stores a program executed by the processor and information used in processing by the processor. The memory may include at least one of a ROM, an EPROM, an EEPROM, a RAM, and a flash memory. The processor may include a digital signal processor (DSP) that performs digital processing of a digital signal, and a central processing unit (CPU) that executes a program. Note that a part of the memory may be provided in the communication unit 120. Also, the DSP may be provided in the communication unit 120.

[0044] In the UE 100 configured in this manner, the control unit 130 determines whether the second network 200B is synchronized with the first network 200A. The communication unit 120 transmits an RRC message including an information element indicating whether the second network 200B is synchronized with the first network 200A to the base station 210A of the first network 200A. This allows the base station 210A communicating with the UE 100 to know whether the second network 200B is synchronized with the first network 200A based on the RRC message received from the UE 100. Therefore, the base station 210A can appropriately set the interruption timing for the UE 100, taking into account whether the second network 200B is synchronized with the first network 200A.

[0045] (Example of base station configuration) An example of the configuration of the base station 210A of the first network 200A will be described with reference to FIG.

[0046] As shown in FIG. 4, the base station 210A includes an antenna 211, a communication unit 212, a network interface 213, and a control unit 214.

[0047] The communication unit 212 communicates with the UE 100 via the antenna 211 under the control of the control unit 214. The communication unit 212 has a receiving unit 212a and a transmitting unit 212b. The receiving unit 212a converts a radio signal received by the antenna 211 into a received signal which is a baseband signal, performs signal processing on the received signal, and outputs the signal to the control unit 214. The transmitting unit 212b performs signal processing on a transmission signal which is a baseband signal output by the control unit 214, converts the transmission signal into a radio signal, and transmits the radio signal from the antenna 211.

[0048] The network interface 213 is connected to the core network 220A. Under the control of the control unit 214, the network interface 213 performs network communication with the mobility management device 221A and the gateway device 222A.

[0049] The control unit 214 controls the communication unit 212 and performs various controls in the base station 210A. The control unit 214 includes at least one processor and at least one memory. The memory stores a program executed by the processor and information used in the processing by the processor. The memory may include at least one of a ROM, an EPROM, an EEPROM, a RAM, and a flash memory. The processor may include a digital signal processor (DSP) that performs digital processing of a digital signal, and a central processing unit (CPU) that executes the program. Note that a part of the memory may be provided in the communication unit 212. Also, the DSP may be provided in the communication unit 212.

[0050] In the base station 210A configured in this manner, the communication unit 212 receives an RRC message including an information element indicating whether or not the second network 200B is synchronized with the first network 200A from the UE 100. The control unit 214 acquires the information element included in this RRC message. This allows the base station 210A communicating with the UE 100 to know whether or not the second network 200B is synchronized with the first network 200A based on the RRC message received from the UE 100. Therefore, the base station 210A can appropriately set the interruption timing for the UE 100, taking into account whether or not the second network 200B is synchronized with the first network 200A.

[0051] (Mobile communication system operation) The operation of the mobile communication system 1 will be described with reference to FIGS.

[0052] (1) Example of UE operation An example of the operation of the UE 100 for which the interruption timing is set by the base station 210A of the first network 200A will be described with reference to FIG.

[0053] In the operation example shown in FIG. 5, it is assumed that the UE 100 is in an RRC connected state in a cell C1 of the first network 200A, and is in an RRC idle state or an RRC inactive state in a cell C2 of the second network 200B.

[0054] 5, the period from time t1 to time t2 and the period from time t3 to time t4 correspond to interruption timings at which the UE 100 interrupts communication with the base station 210A. Here, an example is shown in which a measurement gap is set as the interruption timing at which the radio condition of the second network 200B is used for measurement.

[0055] During each interruption timing, the control unit 130 of the UE 100 switches the network from which the communication unit 120 receives radio signals from the first network 200A to the second network 200B, and establishes synchronization with the second network 200B and measures the reception quality by measuring the SSB (SS / PBCH Block) of the second network 200B.

[0056] An SSB is an example of a known signal. An SSB includes a Primary Synchronization Signal (PSS), a Secondary Synchronization Signal (SSS), a Physical Broadcast Channel (PBCH), and a Demodulation Reference Signal (DMRS). For example, an SSB may be composed of four consecutive OFDM symbols in the time domain. Also, an SSB may be composed of 240 consecutive subcarriers (i.e., 20 resource blocks) in the frequency domain. The PBCH is a physical channel that carries a Master Information Block (MIB).

[0057] The control unit 130 of the UE 100 performs measurement on the SSB of the second network 200B during each interruption timing, and then monitors paging of the second network 200B. The monitoring of paging is to confirm whether or not there is paging addressed to the UE 100 by receiving a PDCCH (Physical Downlink Control CHannel) from the base station 210B of the second network 200B.

[0058] In order to reduce power consumption, the UE 100 discontinuously monitors paging using discontinuous reception (DRX). Such a cycle for monitoring paging is called a DRX cycle. A frame in which the UE 100 should monitor paging is called a paging frame (PF), and a subframe in this PF in which the UE 100 should monitor paging is called a paging occasion (PO).

[0059] Therefore, it is preferable that the interruption timing is a period including the timing of the PF / PO set in the UE 100 and the SSB measurement timing immediately before the PF / PO. However, the UE 100 does not necessarily need to perform SSB measurement for every PF / PO. For example, if the measurement result (including the state of synchronization) of the second network 200B can be maintained even while the UE 100 is communicating with the first network 200A, the UE 100 may perform SSB measurement at a period longer than the DRX period. Therefore, the interruption timing for the SSB measurement and the interruption timing for the paging monitoring may be set separately.

[0060] Further, the interruption timing for interrupting communication with the base station 210A is not limited to being set in the UE 100 as a measurement gap. The interruption timing for interrupting communication with the base station 210A may be set using a DRX (C-DRX) parameter for the RRC connected state. For example, the base station 210A sets the On Duration and the DRX cycle in the UE 100 so that the period from time t2 to time t3 in FIG. 5 is set as an On Duration, which is a reception-on period, and the period from time t1 to time t2 and the period from time t3 to time t4 are set as reception-off periods. The UE 100 performs SSB measurement and paging monitoring of the second network 200B during the reception-off period set by the base station 210A. For this reason, the interruption timing may be set as a measurement gap or may be set as a reception-off period of DRX.

[0061] (2) Example of operation of a mobile communication system An operation example of the mobile communication system 1 according to the first embodiment will be described with reference to Fig. 6. In Fig. 6, it is assumed that the UE 100 is in an RRC idle state or an RRC inactive state in a cell C2 of the second network 200B (base station 210B).

[0062] Step S1: The UE 100 (communication unit 120) receives an SSB from the base station 210A of the first network 200A, and receives an SSB from the base station 210B of the second network 200B. The UE 100 (control unit 130) determines whether the first network 200A and the second network 200B are synchronized based on these SSBs. Specifically, the UE 100 (control unit 130) determines whether the cell C1 of the base station 210A and the cell C2 of the base station 210B are synchronized. Hereinafter, such synchronization determination is referred to as an "inter-network synchronization determination", and the result of the inter-network synchronization determination is referred to as an "inter-network synchronization state".

[0063] The UE 100 (control unit 130) identifies the timing of the frame start of each of the cells C1 and C2 based on, for example, the synchronization signals (PSS·SSS) in the SSB, and compares the timing of the frame start of each of the cells C1 and C2 to determine whether the frame timing of the cells C1 and C2 coincides with each other. If the UE 100 (control unit 130) determines that the frame timing of the cells C1 and C2 does not coincide with each other, it may measure the difference in frame timing between the cells C1 and C2.

[0064] Furthermore, the UE 100 (control unit 130) identifies the SFNs of the cells C1 and C2 based on, for example, the SFN included in the MIB in the SSB, and compares the SFNs of the cells C1 and C2 to determine whether the SFNs of the cells C1 and C2 match. If the UE 100 (control unit 130) determines that the SFNs of the cells C1 and C2 do not match, it may measure the difference in SFN between the cells C1 and C2.

[0065] When the base station 210A and / or the base station 210B is an eNB, the UE 100 (communication unit 120) may receive a synchronization signal (PSS·SSS) and an MIB from the eNB instead of the SSB. The UE 100 (control unit 130) may perform synchronization determination in step S1 based on the received synchronization signal (PSS·SSS) and MIB.

[0066] Step S2: The UE 100 (control unit 130) generates an RRC message including an information element (hereinafter, referred to as "synchronization-related information") indicating whether the second network 200B is synchronized with the first network 200A based on the result of the inter-network synchronization determination in step S1. The UE 100 (communication unit 120) transmits the RRC message including the synchronization-related information to the base station 210A of the first network 200A. The base station 210A (communication unit 212) receives the RRC message.

[0067] The synchronization-related information may include information (i.e., 1-bit flag information) indicating whether or not the SFNs match between the first network 200A and the second network 200B. For example, the information may be "1 (true)" if the SFNs match between the first network 200A and the second network 200B, and "0 (false)" if the SFNs do not match between the first network 200A and the second network 200B. This allows the base station 210A to know whether or not the SFNs match between the first network 200A and the second network 200B. Furthermore, such information makes it possible to reduce the amount of information to be transmitted.

[0068] The synchronization-related information may include information (i.e., 1-bit flag information) indicating whether or not the frame timing is consistent between the first network 200A and the second network 200B. For example, the synchronization-related information may be "1 (true)" if the frame timing is consistent between the first network 200A and the second network 200B, and may be "0 (false)" if the frame timing is not consistent between the first network 200A and the second network 200B. This allows the base station 210A to know whether or not the frame timing is consistent between the first network 200A and the second network 200B. In addition, such information makes it possible to reduce the amount of information to be transmitted.

[0069] The synchronization-related information may include information (i.e., 1-bit flag information) indicating whether or not both the SFN and the frame timing are the same between the first network 200A and the second network 200B. For example, the synchronization-related information may be "1 (true)" if both the SFN and the frame timing are the same between the first network 200A and the second network 200B, and may be "0 (false)" if at least one of the SFN and the frame timing is not the same between the first network 200A and the second network 200B. This allows the base station 210A to know whether or not both the SFN and the frame timing are the same between the first network 200A and the second network 200B. In addition, such information can further reduce the amount of information to be transmitted.

[0070] The synchronization-related information may include at least one of information indicating a difference in SFN between the first network 200A and the second network 200B (e.g., an SFN offset value) and information indicating a difference in frame timing between the first network 200A and the second network 200B (e.g., a frame timing offset value), which allows the base station 210A to grasp a detailed inter-network synchronization state.

[0071] The UE 100 (control unit 130) may include such differential information in the RRC message instead of the above-mentioned 1-bit flag. When the value (differential value) of the differential information indicating the difference in SFN is zero, the base station 210A can consider that the SFNs match between the first network 200A and the second network 200B. Similarly, when the value (differential value) of the differential information indicating the difference in frame timing is zero, the base station 210A can consider that the frame timing matches between the first network 200A and the second network 200B.

[0072] Alternatively, the UE 100 (control unit 130) may include such difference information in combination with the above-mentioned 1-bit flag information in the RRC message. For example, when the SFNs are inconsistent and the frame timings are consistent, the UE 100 (control unit 130) may include, in the RRC message, difference information indicating the difference in SFNs and 1-bit flag information indicating that the frame timings are consistent.

[0073] The UE 100 (control unit 130) may further include at least one of a Public Land Mobile Network (PLMN) ID of the second network 200B and a cell ID of a cell C2 (i.e., a camped-on cell on which the UE 100 is waiting) of the second network 200B in the RRC message. This allows the base station 210A to identify a network and / or a cell on which the UE 100 is waiting, based on the RRC message. The UE 100 (control unit 130) may also include at least one of a base station ID of the base station 210B, a frequency ID of a frequency to which the cell C2 belongs, and information requesting setting of an interruption timing in the RRC message.

[0074] The RRC message transmitted from the UE 100 to the base station 210A in step S2 may be a message used when establishing, re-establishing, or resuming an RRC connection with the base station 210A. That is, the RRC message transmitted from the UE 100 to the base station 210A may be a message transmitted in association with a random access procedure for the UE 100 to transition from an RRC idle state or an RRC inactive state to an RRC connected state. By notifying the base station 210A of synchronization-related information in such an RRC message, the base station 210A can grasp the inter-network synchronization state at the start of communication between the UE 100 and the base station 210A. The RRC message for establishing an RRC connection with the base station 210A may be an RRCSetupComplete message of 5G / NR or an RRCConnectionSetupComplete message of 4G / LTE. The RRC message for re-establishing an RRC connection with the base station 210A may be an RRCReestablishmentComplete message of 5G / NR or an RRCConnectionReestablishmentComplete message of 4G / LTE. The RRC message for resuming the RRC connection with base station 210A may be an RRC ResumeComplete message.

[0075] The RRC message transmitted from the UE 100 to the base station 210A in step S2 may be an assistance information message transmitted by the UE 100 to the base station 210A as assistance information after the UE 100 establishes, re-establishes, or resumes an RRC connection with the base station 210A. That is, the RRC message transmitted from the UE 100 to the base station 210A may be a message transmitted spontaneously by the UE 100 after transitioning to an RRC connected state. By notifying the base station 210A of synchronization-related information in such an RRC message, when the UE 100 determines that measurement and / or paging monitoring of the second network 200B is necessary, it is possible to prompt the base station 210A to set the interruption timing. Note that such an assistance information message may be a UEAssistanceInformation message, or may be an RRC message (e.g., a MultiSIMUEInformation message) newly defined for a multi-SIM supported UE.

[0076] The RRC message transmitted from the UE 100 to the base station 210A in step S2 may be a response message (e.g., a UEInformationResponse message) transmitted by the UE 100 in response to a transmission request from the base station 210A after the UE 100 establishes, re-establishes, or resumes an RRC connection with the base station 210A of the first network 200A. The UE 100 may transmit a message used when establishing, re-establishing, or resuming an RRC connection with the base station 210A as described above, including information indicating that the UE 100 has synchronization-related information to transmit to the base station 210A. The UE 100 may also notify the base station 210A of its capability to support multiple SIMs by using the logical channel ID of the MAC CE in a message 3 transmitted during the random access procedure. Based on such information, the base station 210A transmits a message (e.g., a UEInformationRequest message) requesting transmission of synchronization-related information to the UE 100. In response to this request message, the UE 100 transmits a response message including synchronization-related information to the base station 210A. By notifying the base station 210A of the synchronization related information in such a response message, it becomes possible to perform control such that the base station 210A requests the UE 100 for the synchronization related information only when the base station 210A is capable of setting the interruption timing.

[0077] Note that the base station 210A (the communication unit 212) may broadcast information indicating that the transmission of synchronization related information by the UE 100 is permitted, for example, by including the information in an SIB. The UE 100 (the communication unit 120) may be able to transmit synchronization related information to the base station 210A only when the base station 210A permits the transmission of the synchronization related information.

[0078] Furthermore, the base station 210A (the communication unit 212) may broadcast, for example, information indicating a request for acquisition and transmission of synchronization-related information by the UE 100, by including the information in an SIB. The UE 100 (the communication unit 120) may transmit synchronization-related information to the base station 210A in response to the request from the base station 210A for acquisition and transmission of synchronization-related information.

[0079] Step S3: The base station 210A (control unit 214) determines the interruption timing to be set in the UE 100 based on information included in the RRC message received from the UE 100, and sets the determined interruption timing in the UE 100. For example, the base station 210A (control unit 214) transmits an RRC reconfiguration message including an interruption timing setting indicating the determined interruption timing to the UE 100. The UE 100 (communication unit 120) receives this RRC reconfiguration message. The UE 100 (control unit 130) stores and applies the interruption timing setting included in the received RRC reconfiguration message. The RRC reconfiguration message may be an RRCReconfiguration message of 5G / NR or an RRCConnectionReconfiguration message of 4G / LTE.

[0080] The interruption timing setting set in the UE 100 includes, for example, an interruption period, which is a period of the interruption timing, and an interruption time width, which is a time width of the interruption timing, as setting parameters. When a measurement gap is used as the interruption timing, a measurement gap setting can be used as the interruption timing setting. The measurement gap setting (measurement gap parameter set) may include gapOffset, mgl, mgrp, and mgta. mgl is the measurement gap length of the measurement gap. mgrp is the measurement gap repetition period (MGRP) of the measurement gap. mgta is the measurement gap timing advance. gapOffset is the gap offset of a gap pattern with MGRP.

[0081] When the base station 210A (control unit 214) determines that at least one of the SFN and the frame timing is inconsistent between the first network 200A and the second network 200B based on the synchronization-related information included in the RRC message received from the UE 100, the base station 210A (control unit 214) generates the interruption timing configuration in consideration of the inter-network synchronization state. In this case, the base station 210A (control unit 214) may perform a process of identifying the SFN and / or the frame timing of the second network 200B (cell C2). For example, the base station 210A (control unit 214) may obtain information identifying the SFN and / or the frame timing of the second network 200B (cell C2) from the second network 200B (e.g., base station 210B), or may obtain the information from OAM (Operations Administration Maintenance).

[0082] Step S4: The base station 210A (control unit 214) allocates radio resources to the UE 100 and communicates with the UE 100 at a timing other than the interruption timing set in the UE 100. The UE 100 (control unit 130) monitors the PDCCH of the base station 210A and communicates with the base station 210A at a timing other than the interruption timing set by the base station 210A.

[0083] Step S5: The base station 210A (control unit 214) does not allocate radio resources to the UE 100 at the interruption timing set for the UE 100, and interrupts communication with the UE 100. The UE 100 (control unit 130) interrupts communication with the base station 210A at the interruption timing set by the base station 210A, and measures the radio state of the second network 200B and monitors paging.

[0084] (Summary of the first embodiment) As described above, an RRC message including synchronization-related information, which is an information element indicating whether the second network 200B is synchronized with the first network 200A, is transmitted from the UE 100 to the base station 210A of the first network 200A. This allows the base station 210A communicating with the UE 100 to know whether the second network 200B is synchronized with the first network 200A based on the RRC message received from the UE 100. This allows the base station 210A to appropriately set the interruption timing for the UE 100, taking into account whether the second network 200B is synchronized with the first network 200A.

[0085] [Second embodiment] The second embodiment will be described mainly with respect to the differences from the above-mentioned first embodiment.

[0086] In order for the UE 100 to receive paging from the second network 200B, the UE 100 needs to measure the radio conditions in the second network 200B before monitoring the paging from the second network 200B. The measurement of the radio conditions includes at least one of a process of receiving a synchronization signal to establish synchronization and a process of performing measurement based on a known signal. That is, in order for the UE 100 to measure the radio conditions in the second network 200B, it is necessary to receive a known signal from the base station 210 of the second network 200B.

[0087] In the second embodiment, the control unit 130 of the UE 100 acquires a measurement timing setting indicating the timing at which the UE 100 measures the radio condition in the second network 200B. That is, the control unit 130 acquires a measurement timing setting for measurement based on a known signal in the second network 200B.

[0088] The measurement timing configuration is, for example, an SMTC (SSB measurement timing configuration) window configured in the UE 100 by the base station 210B of the second network 200B. The UE 100 detects and measures the SSB within the configured SMTC window. The SMTC window is specified by the configuration parameters of the SSB measurement period, offset, and measurement time width. The SSB measurement period and offset are the period and offset of the measurement window for receiving the SSB, and are given, for example, by the number of subframes. The measurement period is set to one of 5, 10, 20, 40, 80, and 160 ms, and does not necessarily have to be the same as the actual SSB transmission period. The measurement time width (also referred to as Duration) is the time length of the measurement window for receiving the SSB, and is given, for example, by the number of subframes. Depending on the number of SSBs to be transmitted, one of 1, 2, 3, 4, and 5 ms (i.e., 1, 2, 3, 4, and 5 subframes) is set.

[0089] When base station 210B of second network 200B is an eNB, the timing at which PSS and / or SSS is transmitted (hereinafter also referred to as PSS·SSS window) can be used as the measurement timing setting instead of the SMTC window.

[0090] In the second embodiment, the control unit 130 of the UE 100 generates an RRC message including the acquired measurement timing setting and the above-mentioned synchronization related information. The communication unit 120 of the UE 100 transmits this RRC message to the base station 210A of the first network 200A. After transmitting the RRC message, the communication unit 120 of the UE 100 receives an RRC reconfiguration message from the base station 210A including an interruption timing setting indicating the timing to interrupt communication with the base station 210A. The control unit 130 of the UE 100 interrupts communication with the base station 210A and measures the radio state according to the interruption timing setting.

[0091] In this manner, by transmitting an RRC message including a measurement timing setting in the second network 200B from the UE 100 to the base station 210A, the base station 210A can grasp the measurement timing at which the UE 100 should measure the radio state of the second network 200B. As a result, the base station 210A can determine an appropriate interruption timing taking into consideration the measurement timing of the UE 100 to measure the radio state of the second network 200B.

[0092] An operation example of the mobile communication system 1 according to the second embodiment will be described with reference to Fig. 7. Since the basic operation is similar to that of the first embodiment, differences from the operation example of the mobile communication system 1 according to the first embodiment (see Fig. 6) will be described.

[0093] Step S101: The base station 210B (communication unit 212) of the second network 200B transmits a message including a measurement timing setting in the second network 200B (step S101).

[0094] The message including the measurement timing configuration in the second network 200B may be a system information block (SIB) broadcast from the base station 210B. The UE 100 can receive the SIB not only when the UE 100 is in an RRC connected state for the second network 200B, but also when the UE 100 is in an RRC idle state or an RRC inactive state for the second network 200B. Such an SIB may be an SIB used to control cell reselection of the UE 100 in an RRC idle state or an RRC inactive state, for example, an SIB type 2 or SIB type 4 of 5G / NR. The SIB type 2 is an SIB for intra-frequency cell reselection. The SIB type 4 is an SIB for inter-frequency cell reselection. The UE 100 (communication unit 120) receives such an SIB. The UE 100 (control unit 130) acquires the measurement timing configuration included in the SIB (step S102).

[0095] The message including the measurement timing setting in the second network 200B may be an RRC release (RRCRelease) message transmitted from the base station 210B to the UE 100. The RRC release message is a type of RRC message, and is a message for transitioning the UE 100 from an RRC connected state to an RRC idle state or an RRC inactive state. By notifying the UE 100 of the measurement timing setting in the RRC release message, it is possible to set the measurement timing optimized for each UE in the UE 100. The UE 100 (communication unit 120) receives such an RRC release message. The UE 100 (control unit 130) acquires the measurement timing setting included in the RRC release message (step S102).

[0096] The measurement timing setting is not limited to the above-mentioned SMTC window or PSS·SSS window. The measurement timing setting may be any setting information indicating the timing at which the UE 100 measures the radio condition in the second network 200B. The measurement timing setting includes at least one of a measurement period, an offset, and a measurement time width as a setting parameter.

[0097] The UE 100 (control unit 130) may generate and acquire the measurement timing configuration based on the signal transmission configuration in the second network 200B. For example, in the case of 5G / NR, the signal transmission configuration is at least one of subCarrierSpacingCommon included in the MIB broadcast from the base station 210B, ssb-PeriodicityServingCell included in the SIB type 1 broadcast from the base station 210B, and ssb-PositionsInBurst included in the SIB type 1 broadcast from the base station 210B. subCarrierSpacingCommon is an information element indicating the subcarrier spacing. ssb-PeriodicityServingCell is an information element indicating the transmission period of the SSB. ssb-PositionsInBurst is an information element indicating the position of the SSB in the time domain.

[0098] Step S103: The UE 100 (control unit 130) performs inter-network synchronization determination in the same manner as in the first embodiment. Note that step S103 may be performed simultaneously with step S102, or may be performed before step S102.

[0099] Step S104: The UE 100 (control unit 130) generates an RRC message including the measurement timing configuration acquired in step S102 and the synchronization-related information acquired in step S103. Then, the UE 100 (communication unit 120) transmits the RRC message including the measurement timing configuration to the base station 210A of the first network 200A.

[0100] Step S105: The base station 210A (control unit 214) determines the interruption timing to be set in the UE 100 based on the synchronization-related information and the measurement timing setting included in the RRC message received from the UE 100. For example, the base station 210A (control unit 214) determines the period and time width of the interruption timing so as to cover the timing at which the UE 100 measures the second network 200B. Here, the base station 210A (control unit 214) determines the interruption timing in consideration of the inter-network synchronization state. The base station 210A (control unit 214) generates an RRC reconfiguration message including an interruption timing setting indicating the determined interruption timing.

[0101] Step S106: The base station 210A (communication unit 212) transmits an RRC reconfiguration message including a suspend timing setting to the UE 100. The UE 100 (communication unit 120) receives this RRC reconfiguration message. The UE 100 (control unit 130) stores and applies the suspend timing setting included in the received RRC reconfiguration message.

[0102] Step S107: The UE 100 (communication unit 120) transmits an RRC reconfiguration completion message indicating that the configuration by the RRC reconfiguration message from the base station 210A has been completed to the base station 210A. The base station 210A (communication unit 212) receives the RRC reconfiguration completion message.

[0103] Step S108: The base station 210A (control unit 214) allocates radio resources to the UE 100 and communicates with the UE 100 at a timing other than the interruption timing set in the UE 100. The UE 100 (control unit 130) monitors the PDCCH of the base station 210A and communicates with the base station 210A at a timing other than the interruption timing set by the base station 210A.

[0104] Step S109: The base station 210A (control unit 214) does not allocate radio resources to the UE 100 at the interruption timing set for the UE 100, and interrupts communication with the UE 100. The UE 100 (control unit 130) interrupts communication with the base station 210A at the interruption timing set by the base station 210A, and measures the radio state of the second network 200B.

[0105] In this way, according to the second embodiment, the UE 100 can measure the radio state of the second network 200B using the interruption timing setting that takes into account the measurement timing setting of the second network 200B. Therefore, it is possible to interrupt communication with the base station 210A for the minimum necessary time, and it is possible to suppress a decrease in the throughput of communication with the base station 210A. Then, by monitoring paging of the second network 200B after measuring the radio state of the second network 200B, it is possible to appropriately receive paging of the second network 200B.

[0106] [Modification of the second embodiment] The modified example of the second embodiment will be described mainly with respect to the differences from the above-described second embodiment.

[0107] In a modification of the second embodiment, the control unit 130 of the UE 100 further acquires a paging parameter set for identifying the timing (i.e., PF / PO) at which the UE 100 monitors paging in the second network 200B. The communication unit 120 of the UE 100 transmits an RRC message further including the paging parameter set to the base station 210A. This allows the base station 210A to know the timing at which the UE 100 should monitor paging of the second network 200B. As a result, the base station 210A can determine an appropriate interruption timing taking into consideration the timing at which the UE 100 monitors paging of the second network 200B.

[0108] In a modification of the second embodiment, the communication unit 120 of the UE 100 receives an RRC reconfiguration message including an interruption timing setting indicating the timing to interrupt communication with the base station 210A to measure the radio state and monitor paging from the base station 210A after transmitting an RRC message. The control unit 130 of the UE 100 interrupts communication with the base station 210A in accordance with the interruption timing setting, and measures the radio state and monitors paging.

[0109] This allows the UE 100 to monitor paging of the second network 200B using an interruption timing setting that takes into account the paging parameter set of the second network 200B. This makes it possible to interrupt communication with the base station 210A for the minimum time required for measuring the radio state of the second network 200B and monitoring paging, thereby suppressing a decrease in the throughput of communication with the base station 210A.

[0110] A modification of the second embodiment will be described with reference to FIG.

[0111] Steps S111 and S112: The base station 210B (communication unit 212) of the second network 200B transmits a message including a measurement timing setting in the second network 200B (step S111). The UE 100 (control unit 130) acquires the measurement timing setting included in the message from the base station 210B (step S112). In a modification of the second embodiment, the UE 100 (control unit 130) acquires not only the measurement timing setting but also a paging parameter set (step S112).

[0112] For example, the paging parameter set includes a parameter set for identifying a PF and a PO of paging in the second network 200B. First, the paging parameter set may include configuration information for paging. The configuration information may be PCCH-Config. The configuration information is included in system information transmitted in the second network 200B. The UE 200 (communication unit 120) receives the system information in the second network 200B. Then, the UE 200 (control unit 130) acquires the configuration information included in the system information.

[0113] Secondly, the paging parameter set includes an ID of the UE 100 in the second network 200B. For example, when the base station 210B of the second network 200B is a gNB, the ID is a Temporary Mobile Subscriber Identity (5G-S-TMSI) of the UE 100 in the second network 200B or the least significant 10 bits of the 5G-S-TMSI. When the base station 210B of the second network 200B is an eNB, the ID is an IMSI of the UE 100 in the second network 200B or the least significant 10 bits of the IMSI.

[0114] Here, we will explain how to determine the PF and PO. In the case of 5G / NR, the PF is determined by the following formula:

[0115] (SFN + PF_offset) mod T = (T div N)*(UE_ID mod N) SFN is the SFN of the PF. PF_offset is an offset used to determine the PF. T is the DRX (discontinuous reception) cycle of the UE 100. UE_ID is the least significant 10 bits of the 5G-S-TMSI. N is the total number of PFs in T. For example, T is indicated by defaultPagingCycle included in the PCCH-Config. For example, N and PF_offset are indicated by nAndPagingFrameOffset included in the PCCH-Config.

[0116] For 5G / NR, the PO is determined by the following formula: i_s = floor(UE_ID / N) mod Ns i_s indicates the index of the PO. UE_ID is the least significant 10 bits of 5G-S-TMSI. N is the total number of PFs in T. T is the DRX cycle of UE 100. Ns is the number of POs for a PF. For example, N is indicated by nAndPagingFrameOffset included in PCCH-Config. Ns is indicated by ns included in PCCH-Config. A PO is associated with a PF. For example, a PO starts within or after a PF.

[0117] For 4G / LTE, the PF is determined by the following formula: SFN mod T = (T div N)*(UE_ID mod N) SFN is the SFN of the PF. T is the DRX cycle of the UE 100. N is the smaller of T and nB. nB is a parameter to be configured. UE_ID is the least significant 10 bits of the IMSI. For example, T is indicated by the defaultPagingCycle included in the PCCH-Config. nB is indicated by the nB included in the PCCH-Config.

[0118] For 4G / LTE, the PO is determined by the following formula: i_s = floor(UE_ID / N) mod Ns i_s indicates the index of the PO. UE_ID is the least significant 10 bits of the IMSI. N is the smaller of T and nB. T is the DRX cycle of the UE 100, and nB is a configured parameter. Ns is the larger of 1 and nB / T. For example, T is indicated by the defaultPagingCycle included in the PCCH-Config. nB is indicated by the nB included in the PCCH-Config.

[0119] Step S113: The UE 100 (control unit 130) performs inter-network synchronization determination in the same manner as in the first embodiment. Note that step S113 may be performed simultaneously with step S112, or may be performed before step S112.

[0120] Step S114: The UE 100 (control unit 130) generates an RRC message including the measurement timing configuration and the paging parameter set acquired in step S112 and the synchronization-related information acquired in step S113. Then, the UE 100 (communication unit 120) transmits this RRC message to the base station 210A of the first network 200A.

[0121] Step S115: The base station 210A (control unit 214) determines the interruption timing to be set in the UE 100 based on the measurement timing setting, the paging parameter set, and the synchronization related information included in the RRC message received from the UE 100. The base station 210A (control unit 214) determines the period and time width of the interruption timing so as to cover the timing (e.g., SMTC window) at which the UE 100 measures the second network 200B and the timing (e.g., PF / PO) at which the UE 100 monitors paging. The base station 210A (control unit 214) generates an RRC reconfiguration message including an interruption timing setting indicating the determined interruption timing.

[0122] Step S116: The base station 210A (communication unit 212) transmits an RRC reconfiguration message including a suspend timing setting to the UE 100. The UE 100 (communication unit 120) receives this RRC reconfiguration message. The UE 100 (control unit 130) stores and applies the suspend timing setting included in the received RRC reconfiguration message.

[0123] Step S117: The UE 100 (communication unit 120) transmits an RRC reconfiguration completion message indicating that the configuration by the RRC reconfiguration message from the base station 210A has been completed to the base station 210A. The base station 210A (communication unit 212) receives the RRC reconfiguration completion message.

[0124] Step S118: The base station 210A (control unit 214) allocates radio resources to the UE 100 and communicates with the UE 100 at a timing other than the interruption timing set in the UE 100. The UE 100 (control unit 130) monitors the PDCCH of the base station 210A and communicates with the base station 210A at a timing other than the interruption timing set by the base station 210A.

[0125] Step S119: The base station 210A (control unit 214) does not allocate radio resources to the UE 100 at the interruption timing set for the UE 100, and interrupts communication with the UE 100. The UE 100 (control unit 130) interrupts communication with the base station 210A at the interruption timing set by the base station 210A, measures the radio state of the second network 200B, and monitors paging of the second network 200B.

[0126] [Other embodiments] In the operation of the above-described embodiment, the first network 200A and the base station 210A may be read as a cell C1 (first cell), and the first network 200A and the base station 210A may be read as a cell C2 (second cell).

[0127] The steps in the operations of the above-described embodiments do not necessarily have to be executed in chronological order according to the order described in the flow diagram or sequence diagram. For example, the steps in the operations may be executed in an order different from that described in the flow diagram or sequence diagram, or may be executed in parallel. Some of the steps in the operations may be deleted, and additional steps may be added to the process. Furthermore, each of the above-described operation flows is not limited to being executed separately and independently, but may be executed by combining two or more operation flows. For example, some steps of one operation flow may be added to another operation flow, or some steps of one operation flow may be replaced with some steps of another operation flow.

[0128] A program may be provided that causes a computer to execute each process performed by the UE 100 or the base station 210. The program may be recorded in a computer-readable medium. Using the computer-readable medium, it is possible to install the program in the computer. Here, the computer-readable medium on which the program is recorded may be a non-transient recording medium. The non-transient recording medium is not particularly limited, and may be, for example, a recording medium such as a CD-ROM or a DVD-ROM. In addition, a circuit that executes each process performed by the UE 100 or the base station 210 may be integrated, and at least a part of the UE 100 or the base station 210 may be configured as a semiconductor integrated circuit (chip set, SoC).

[0129] In the above embodiment, "transmit" may mean performing processing of at least one layer in a protocol stack used for transmission, or may mean physically transmitting a signal wirelessly or by wire. Alternatively, "transmit" may mean a combination of performing processing of at least one layer and physically transmitting a signal wirelessly or by wire. Similarly, "receive" may mean performing processing of at least one layer in a protocol stack used for reception, or may mean physically receiving a signal wirelessly or by wire. Alternatively, "receive" may mean a combination of performing processing of at least one layer and physically receiving a signal wirelessly or by wire.

[0130] The above describes the embodiments in detail with reference to the drawings, but the specific configuration is not limited to that described above, and various design changes, etc. are possible without departing from the spirit of the invention. [Explanation of symbols]

[0131] 1: Mobile communication systems 100:UE 101: Antenna 120: Communications Department 121: Receiving unit 122: Transmitter 130: Control section 200:Base station 200A: First network 200B: Second network 210A:Base station 210B:Base station 211: Antenna 212: Communications Department 212a: Receiving section 212b: Transmitter 213: Network interface 214: Control section 220A: Core Network 220B: Core Network 221A: Mobility management device 221B: Mobility management device 222A: Gateway device 222B: Gateway device

Claims

1. A communication device (100) for communicating with a plurality of networks (200A, 200B) using a plurality of subscriber identity modules (111, 112), a communication unit (120) that communicates with a base station (210A) of a first network (200A) included in the plurality of networks (200A, 200B); The communication unit (120) Sending a UEAssistanceInformation message to the base station (210A) including information requesting the setting of a gap in the first network (200A); receiving an RRC reconfiguration message from the base station (210A) including a configuration of the gap according to the information; The gap settings include a gap length, a gap repeat period, and a gap offset. A communication device (100).

2. The communication unit (120) Transmitting capability information to said base station (210A) for supporting said plurality of subscriber identity modules. The communication device (100) of claim 1.

3. A base station (210A) of a first network (200A), A receiving unit that receives a UEAssistanceInformation message from a communication device (100) including information requesting setting of a gap in the first network (200A); A transmission unit that transmits an RRC reconfiguration message including a setting of the gap according to the information to the communication device (100), The gap settings include the length of the gap, the repeat period of the gap, and the offset of the gap. Including offsets, Base station (210A).

4. A communication control method executed by a communication device (100) that communicates with a plurality of networks (200A, 200B) using a plurality of subscriber identity modules (111, 112), comprising: transmitting a UEAssistanceInformation message including information requesting a gap setting in a first network (200A) included in the plurality of networks (200A, 200B) to a base station (210A) of the first network (200A); receiving an RRC reconfiguration message from the base station (210A) including a configuration of the gap according to the information; The gap settings include a gap length, a gap repeat period, and a gap offset. Communication methods.

5. and transmitting capability information for supporting the plurality of subscriber identity modules to the base station (210A). The communication method according to claim 4.

Images