Communication system, communication terminal, and network

Abstract

The invention provides a technology capable of performing rapid NW connection. A communication system includes a communication terminal, and a plurality of networks configured so as to be capable of wireless communication with the communication terminal. A communication terminal determines whether there is a conflicting page among a plurality of pages transmitted from each of a plurality of networks to the communication terminal (ST1615). Upon detecting a collision of paging, the communication terminal notifies at least one of the networks that transmit the collision-causing paging of the collision of the collision of the paging (ST1629).

Description

This application is a divisional application of an application with a filing date of "August 27, 2020", application number "202080048265.2", and title "Communication System, Communication Terminal and Network". Technical Field

[0001] The present disclosure relates to wireless communication technology. Background Art

[0002] In the 3rd Generation Partnership Project (3GPP), a standardization body for mobile communication systems, a communication method called Long Term Evolution (LTE) in terms of wireless sections and System Architecture Evolution (SAE) in terms of the overall system structure including a core network and a radio access network (hereinafter collectively referred to as a network) is studied (e.g., non-patent documents 1 to 5). This communication method is also called a 3.9G (3.9 generation) system.

[0003] For LTE access methods, OFDM (Orthogonal Frequency Division Multiplexing) is used in the downlink direction, and SC-FDMA (Single Career Frequency Division Multiple Access) is used in the uplink direction. In addition, unlike W-CDMA (Wideband Code Division Multiple Access), LTE does not include line switching, but only uses packet communication.

[0004] use Figure 1 The decision matters concerning the frame structure of the LTE system in 3GPP described in Non-Patent Document 1 (Chapter 5) are described. Figure 1 This is an explanatory diagram showing the structure of a radio frame used in a communication system of the LTE method. Figure 1In the IEEE 802.11 standard, a radio frame is 10ms. A radio frame is divided into ten subframes of equal size. A subframe is divided into two slots of equal size. The first and sixth subframes of each radio frame contain a downlink synchronization signal. The synchronization signal includes a primary synchronization signal (P-SS) and a secondary synchronization signal (S-SS).

[0005] Non-Patent Document 1 (Chapter 5) describes the decisions made by 3GPP regarding the channel structure of the LTE system. It is assumed that the same channel structure as that of the non-CSG cell is used in the CSG (Closed Subscriber Group) cell.

[0006] The Physical Broadcast Channel (PBCH) is a downlink transmission channel from a base station device (hereinafter sometimes referred to as "base station") to a communication terminal device (hereinafter sometimes referred to as "communication terminal") such as a mobile terminal device (hereinafter sometimes referred to as "mobile terminal"). The BCH transport block is mapped to four subframes in a 40ms interval. There is no clear signaling of 40ms timing.

[0007] The Physical Control Format Indicator Channel (PCFICH) is a downlink transmission channel from a base station to a communication terminal. The PCFICH notifies the communication terminal from the base station about the number of OFDM (Orthogonal Frequency Division Multiplexing) symbols used for PDCCHs. The PCFICH is transmitted in each subframe.

[0008] The Physical Downlink Control Channel (PDCCH) is a channel for downlink transmission from the base station to the communication terminal. PDCCH notifies the resource allocation information of the downlink shared channel (DL-SCH), one of the transmission channels described later, the resource allocation information of the paging channel (PCH), one of the transmission channels described later, and the HARQ (Hybrid Automatic Repeat reQuest) information related to DL-SCH. PDCCH transmits the uplink scheduling grant. PDCCH transmits the response signal to the uplink transmission, namely ACK (Acknowledgement) / Nack (Negative Acknowledgement). PDCCH is also called L1 / L2 control signal.

[0009] The Physical Downlink Shared Channel (PDSCH) is a downlink transmission channel from a base station to a communication terminal. A downlink shared channel (DL-SCH) as a transport channel and a PCH as a transport channel are mapped to the PDSCH.

[0010] A physical multicast channel (PMCH) is a channel for downlink transmission from a base station to a communication terminal. A multicast channel (MCH) as a transport channel is mapped to the PMCH.

[0011] The Physical Uplink Control Channel (PUCCH) is a channel for uplink transmission from the communication terminal to the base station. PUCCH transmits the response signal (response signal) to the downlink transmission, namely ACK / Nack. PUCCH transmits CSI (Channel State Information). CSI is composed of RI (Rank Indicator), PMI (Precoding Matrix Indicator), and CQI (Channel Quality Indicator) reports. RI refers to the rank information of the channel matrix of MIMO. PMI refers to the information of the precoding waiting matrix used in MIMO. CQI is quality information indicating the quality of the received data, or the quality of the communication line. PUCCH also transmits a scheduling request (Scheduling Request: SR).

[0012] The physical uplink shared channel (PUSCH) is a channel for uplink transmission from a communication terminal to a base station. An uplink shared channel (UL-SCH), which is one of the transport channels, is mapped to the PUSCH.

[0013] The Physical Hybrid ARQ Indicator Channel (PHICH) is a channel for downlink transmission from a base station to a communication terminal. PHICH transmits ACK / Nack, a response signal to uplink transmission. The Physical Random Access Channel (PRACH) is a channel for uplink transmission from a communication terminal to a base station. PRACH transmits a random access preamble.

[0014] The downlink reference signal (Reference Signal: RS) is a known codeword in the LTE communication system. The following five types of downlink reference signals are defined. Cell-specific Reference Signal (CRS), MBSFN Reference Signal (MBSFN Reference Signal), UE-specific Reference Signal (UE-specific Reference Signal) i.e., Data Demodulation Reference Signal (Demodulation Reference Signal: DM-RS), Positioning Reference Signal (Positioning Reference Signal: PRS), Channel Information Reference Signal (Channel State Information Reference Signal: CSI-RS). The measurement of the physical layer of the communication terminal includes the measurement of the reference signal received power (Reference Signal Received Power: RSRP).

[0015] The uplink reference signal is also a symbol known as a communication system of the LTE scheme. The following two types of uplink reference signals are defined: a data demodulation reference signal (Demodulation Reference Signal: DM-RS) and a sounding reference signal (Sounding Reference Signal: SRS).

[0016] The transport channel described in Non-Patent Document 1 (Chapter 5) is described below. The broadcast channel (BCH) in the downlink transport channel is broadcast to the entire coverage area of ​​its base station (cell). The BCH is mapped to the physical broadcast channel (PBCH).

[0017] Retransmission control using HARQ (HybridARQ) is applied to the downlink shared channel (DL-SCH). DL-SCH can be broadcast to the entire coverage area of ​​the base station (cell). DL-SCH supports dynamic or semi-static resource allocation. Quasi-static resource allocation is also called persistent scheduling. In order to reduce the power consumption of the communication terminal, DL-SCH supports discontinuous reception (DRX) of the communication terminal. DL-SCH is mapped to the physical downlink shared channel (PDSCH).

[0018] The Paging Channel (PCH) supports DRX of the communication terminal in order to reduce the power consumption of the communication terminal. The PCH request is broadcast to the entire coverage area of ​​the base station (cell). The PCH is mapped to a physical resource such as the Physical Downlink Shared Channel (PDSCH) that can be dynamically used for traffic.

[0019] The Multicast Channel (MCH) is used to broadcast to the entire coverage area of ​​the base station (cell). MCH supports SFN synthesis of MBMS (Multimedia Broadcast Multicast Service) services (MTCH and MCCH) in multi-cell transmission. MCH supports quasi-static resource allocation. MCH is mapped to PMCH.

[0020] The uplink shared channel (UL-SCH) in the uplink transmission channel is applied with retransmission control using HARQ (Hybrid ARQ). UL-SCH supports dynamic or semi-static resource allocation. UL-SCH is mapped to the physical uplink shared channel (PUSCH).

[0021] The Random Access Channel (RACH) is limited to control information. There is a risk of collision in RACH. RACH is mapped to the Physical Random Access Channel (PRACH).

[0022] HARQ is explained. HARQ is a technology that improves the communication quality of the transmission path by combining Automatic Repeat reQuest (ARQ) and Forward Error Correction (Forward Error Correction). HARQ has the following advantages: even for a transmission line with changed communication quality, error correction can be effectively used by retransmission. In particular, when retransmitting, the quality can be further improved by synthesizing the reception result of the initial transmission and the reception result of the retransmission.

[0023] An example of the retransmission method is described. When the receiving side cannot correctly decode the received data, in other words, when a CRC (Cyclic Redundancy Check) error occurs (CRC=NG), "Nack" is sent from the receiving side to the sending side. The sending side that receives "Nack" retransmits the data. When the receiving side can correctly decode the received data, in other words, when no CRC error occurs (CRC=OK), "Ack" is sent from the receiving side to the sending side. The sending side that receives "Ack" sends the next data.

[0024] The logical channel described in Non-Patent Document 1 (Chapter 6) is described below. The Broadcast Control Channel (BCCH) is a downlink channel used to broadcast system control information. The logical channel, BCCH, is mapped to the transport channel, the Broadcast Channel (BCH), or the Downlink Shared Channel (DL-SCH).

[0025] The Paging Control Channel (PCCH) is a downlink channel used to send paging information and changes to system information. PCCH is used when the network does not know the cell location of the communication terminal. The logical channel, PCCH, is mapped to the transport channel, Paging Channel (PCH).

[0026] The Common Control Channel (CCCH) is a channel used to send control information between a communication terminal and a base station. The CCCH is used in the following situations: that is, when there is no RRC connection between the communication terminal and the network. In the downlink direction, the CCCH is mapped to the downlink shared channel (DL-SCH) as a transmission channel. In the uplink direction, the CCCH is mapped to the uplink shared channel (UL-SCH) as a transmission channel.

[0027] The multicast control channel (MCCH) is a downlink channel used for one-to-many transmission. The MCCH is used to send MBMS control information for one or more MTCHs from the network to the communication terminal. The MCCH is only used by the communication terminal that is receiving MBMS. The MCCH is mapped to the multicast channel (MCH) as a transport channel.

[0028] Dedicated Control Channel (DCCH) is a channel used to send dedicated control information between a communication terminal and a network in a one-to-one manner. DCCH is used in the following situations: that is, when the communication terminal is in an RRC connection. DCCH is mapped to the uplink shared channel (UL-SCH) in the uplink and to the downlink shared channel (DL-SCH) in the downlink.

[0029] Dedicated Traffic Channel (DTCH) is a channel for one-to-one communication with dedicated communication terminals for sending user information. DTCH exists in both uplink and downlink. DTCH is mapped to the uplink shared channel (UL-SCH) in the uplink and to the downlink shared channel (DL-SCH) in the downlink.

[0030] The multicast traffic channel (MTCH) is a downlink channel for transmitting traffic data from the network to the communication terminal. The MTCH is a channel used only by the communication terminal receiving the MBMS. The MTCH is mapped to the multicast channel (MCH).

[0031] CGI is the Cell Global Identifier. ECGI is the E-UTRAN Cell Global Identifier. CSG (Closed Subscriber Group) cells are introduced in LTE, LTE-A (Long Term Evolution Advanced) and UMTS (Universal Mobile Telecommunication System).

[0032] The location tracking of the communication terminal is performed in units of an area consisting of one or more cells. The location tracking is performed to track the location of the communication terminal even in the standby state, so as to call the communication terminal, in other words, to be able to call the communication terminal. The area used for the location tracking of the communication terminal is called a tracking area.

[0033] In addition, 3GPP has developed standards for Long Term Evolution Advanced (LTE-A) as Release 10 (see Non-Patent Documents 3 and 4). LTE-A is based on the wireless communication method of LTE and adds some new technologies thereto.

[0034] In the LTE-A system, in order to support a wider frequency bandwidth (transmission bandwidths) up to 100 MHz, carrier aggregation (CA) of aggregating (also called "aggregation") two or more component carriers (CC) is studied. CA is described in Non-Patent Document 1.

[0035] When CA is configured, the UE has a unique RRC connection (RRCconnection) with the network (Network: NW). In the RRC connection, NAS mobility information and security input are provided by a serving cell. This cell is called the primary serving cell (Primary Cell: PCell). In the downlink, the carrier corresponding to the PCell is the downlink primary component carrier (Downlink Primary Component Carrier: DL PCC). In the uplink, the carrier corresponding to the PCell is the uplink primary component carrier (Uplink Primary Component Carrier: UL PCC).

[0036] According to the capability of UE, a secondary cell (SCell) is formed to form a group of PCell and serving cell. In the downlink, the carrier corresponding to SCell is the downlink secondary component carrier (DL SCC). In the uplink, the carrier corresponding to SCell is the uplink secondary component carrier (UL SCC).

[0037] For one UE, a group of service cells consisting of one PCell and one or more SCells is formed.

[0038] New technologies in LTE-A include technologies supporting wider bandwidth (Wider bandwidth extension) and coordinated multiple point transmission and reception (CoMP) technology, etc. CoMP studied by 3GPP for LTE-A is described in Non-Patent Document 1.

[0039] In addition, in order to cope with the huge volume of traffic in the future, 3GPP is studying the use of small cell eNBs (hereinafter sometimes referred to as "small-scale base station devices") that constitute small cell cells. For example, the technology of increasing the communication capacity by setting up multiple small cell eNBs to form multiple small cell cells is explored. Specifically, there is dual connectivity (DC) in which the UE communicates with two eNBs. DC is described in Non-Patent Document 1.

[0040] Sometimes, one of the eNBs performing dual connectivity (DC) is called a "master eNB (abbreviated as MeNB)" and the other is called a "secondary eNB (abbreviated as SeNB)".

[0041] Mobile network traffic is increasing, and communication speeds are also increasing. If LTE and LTE-A are put into full-scale use, communication speeds will be further increased.

[0042] In addition, the fifth generation (hereinafter sometimes referred to as "5G") wireless access system is being studied with the goal of starting service for the upgraded mobile communication after 2020. For example, in Europe, the METIS organization is summarizing the requirements for 5G (see Non-Patent Document 5).

[0043] In the 5G wireless access system, with respect to the LTE system, assuming that the system capacity is 1000 times, the data transmission speed is 100 times, the data processing delay is 1 / 10, and the number of simultaneous connections of communication terminals is 100 times, further low power consumption and low cost of the device can be listed as necessary conditions.

[0044] In order to meet such requirements, 3GPP is advancing the discussion of 5G standards as Release 15 (see Non-Patent Documents 6 to 18). The technology of the wireless section of 5G is called "New Radio Access Technology" ("New Radio" is abbreviated as "NR").

[0045] Discussions on the NR system based on the LTE system and LTE-A system are continuously advancing, but changes and additions from the LTE system and LTE-A system are made in the following point.

[0046] As the access method of NR, OFDM is used in the downlink direction, and OFDM and DFT-s-OFDM (DFT-spread-OFDM) are used in the uplink direction.

[0047] In NR, higher frequencies can be used compared to LTE to increase transmission speeds and reduce processing delays.

[0048] In NR, an effort is made to ensure cell coverage by forming a narrow beam-shaped transmission and reception range (beamforming) while changing the direction of the beam (beam scanning).

[0049] The NR frame structure supports various subcarrier spacings, that is, various parameter sets (Numerology). In NR, regardless of the parameter set, 1 subframe is 1 millisecond, and 1 time slot consists of 14 code elements. In addition, the number of time slots included in 1 subframe is 1 in the parameter set with a subcarrier spacing of 15kHz, and increases in proportion to the subcarrier spacing in other parameter sets (see Non-Patent Document 13 (TS38.211 v15.2.0)).

[0050] The downlink synchronization signal in NR is sent from the base station as a synchronization signal burst (Synchronization Signal Burst; sometimes referred to as SS burst below) at a specified period for a specified duration. The SS burst consists of a synchronization signal module (Synchronization Signal Block; sometimes referred to as SS module below) for each beam of the base station. The base station changes the beam to send the SS module of each beam during the duration of the SS burst. The SS module consists of P-SS, S-SS and PBCH.

[0051] In NR, a phase tracking reference signal (PTRS) is added as a downlink reference signal of NR to reduce the influence of phase noise. PTRS is also added to the uplink reference signal in the same way as the downlink.

[0052] In NR, in order to flexibly switch DL / UL within a time slot, a time slot format indication (Slot Format Indication: SFI) is added to the information included in the PDCCH.

[0053] In addition, in NR, the base station pre-sets a part of the carrier frequency band (hereinafter sometimes referred to as Bandwidth Part (BWP)) for the UE, and the UE transmits and receives between itself and the base station in this BWP, thereby striving to reduce power consumption in the UE.

[0054] In 3GPP, as DC methods, DC performed by LTE base stations and NR base stations connected to EPC, DC performed by NR base stations connected to 5G core systems, and DC performed by LTE base stations and NR base stations connected to 5G core systems are discussed (refer to non-patent documents 12, 16, and 19).

[0055] In addition, 3GPP is studying several new technologies, such as the operation of a terminal using multiple SIMs (Subscriber Identity Modules) (see Non-Patent Documents 20 and 21). Prior art literature [Non-patent literature]

[0056] Non-patent document 1: 3GPP TS 36.300 V15.4.0 Non-patent document 2: 3GPP S1-083461 Non-patent document 3: 3GPP TR 36.814 V9.2.0 Non-patent document 4: 3GPP TR 36.912 V15.0.0 Non-patent document 5: “Scenarios, requirements and KPIs for 5G mobile and wireless system”, ICT-317669-METIS / D1.1 Non-patent document 6: 3GPP TR 23.799 V14.0.0 Non-patent document 7: 3GPP TR 38.801 V14.0.0 Non-patent document 8: 3GPP TR 38.802 V14.2.0 Non-patent document 9: 3GPP TR 38.804 V14.0.0 Non-patent document 10: 3GPP TR 38.912 V14.1.0 Non-patent document 11: 3GPP RP-172115 Non-patent document 12: 3GPP TS 37.340 V15.2.0 Non-patent document 13: 3GPP TS 38.211 V15.2.0 Non-patent document 14: 3GPP TS 38.213 V15.2.0 Non-patent document 15: 3GPP TS 38.214 V15.2.0 Non-patent document 16: 3GPP TS 38.300 V15.2.0 Non-patent document 17: 3GPP TS 38.321 V15.2.0 Non-patent document 18: 3GPP TS 38.212 V15.2.0 Non-Patent Document 19: 3GPP RP-161266 Non-patent document 20: 3GPP RP-191304 Non-patent document 21: 3GPP RP-191347 Non-patent document 22: 3GPP TS23.501V16.1.0 Non-patent document 23: 3GPP TR 23.734 V16.2.0 Non-patent document 24: 3GPP TS 38.331 V15.6.0 Non-patent document 25: 3GPP TS 38.304 V15.4.0 Non-patent document 26: 3GPP TS 38.413 V15.4.0 Non-patent document 27: 3GPP TS24.501V16.1.0 Non-patent document 28: 3GPP TS 38.423 V15.4.0 Summary of the invention Technical problem to be solved by the invention

[0057] In 3GPP, the operation of UE using multiple SIMs is studied, for example, the countermeasures when the timing of paging to the UE from two NWs overlaps (see non-patent documents 20 and 21). However, non-patent documents 20 and 21 do not disclose a specific method for avoiding the duplication of paging timing, in other words, avoiding paging conflicts. Therefore, the paging conflict between the two NWs cannot be avoided. As a result, the problem of not being able to quickly start the connection between the UE and one NW in the communication system occurs.

[0058] In view of the above problems, one of the objectives of the present disclosure is to provide a technology that can quickly perform NW connection. Technical solutions to technical problems

[0059] According to the present invention, there is provided a communication system, comprising: a communication terminal; and a plurality of networks configured to perform wireless communication with the communication terminal, the communication system being characterized in that the communication terminal determines whether there is a conflicting paging among a plurality of pagings respectively sent from the plurality of networks to the communication terminal, and when a conflict of the paging is detected, notifies at least one of the networks that sent the paging causing the conflict of the paging. According to the present invention, there is provided a communication terminal which is configured to conduct wireless communications with a plurality of networks, wherein the communication terminal determines whether there is a conflicting paging among a plurality of pagings respectively sent from the plurality of networks to the communication terminal, and when a conflict of the pagings is detected, notifies at least one of the networks which sent the paging causing the conflict of the paging. According to the present invention, there is provided a network configured to be capable of wirelessly communicating with a communication terminal, wherein the communication terminal determines whether a paging sent from the network to the communication terminal conflicts with a paging sent from another network to the communication terminal, and when the network is notified of the conflict of the paging, the network changes the timing of sending the paging to the communication terminal. Effects of the Invention

[0060] According to the present disclosure, fast NW connection can be performed.

[0061] The objects, features, aspects and advantages of the present disclosure will become more apparent from the following detailed description and accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0062] Figure 1 This is an explanatory diagram showing the structure of a radio frame used in a communication system of the LTE method. Figure 2 This is a block diagram showing the overall configuration of a communication system 200 of the LTE scheme being discussed in 3GPP. Figure 3 This is a block diagram showing the overall structure of a communication system 210 using the NR method discussed in 3GPP. Figure 4 This is a structural diagram of DC based on eNB and gNB connected to EPC. Figure 5 This is a structural diagram of DC based on gNB connected to the NG core. Figure 6 This is a structural diagram of DC based on eNB and gNB connected to the NG core. Figure 7 This is a structural diagram of DC based on eNB and gNB connected to the NG core. Figure 8Yes means Figure 2 A block diagram of the structure of the mobile terminal 202 is shown. Fig. 9 Yes means Figure 2 A block diagram of the structure of the base station 203 is shown. Fig.10 It is a block diagram showing the structure of MME. Fig.11 It is a block diagram showing the structure of 5GC. Fig.12 This is a flowchart outlining the operations from cell search to standby performed by a communication terminal (UE) in an LTE communication system. Fig.13 is a diagram showing an example of a cell structure in an NR system. Fig.14 This is an architectural diagram showing an example of connection between a UE equipped with multiple SIMs and multiple NWs in accordance with the first embodiment. Fig.15 This is a diagram showing an example of paging collision from a plurality of NWs in accordance with the first embodiment. Fig.16 This is a sequence diagram showing a first example of the operation of a UE equipped with a plurality of SIM cards detecting a paging conflict and notifying a base station of the same, in accordance with the first embodiment. Fig.17 This is a sequence diagram showing a first example of the operation of a UE equipped with a plurality of SIM cards detecting a paging conflict and notifying a base station of the same, in accordance with the first embodiment. Fig.18 This is a sequence diagram showing a second example of the operation of a UE equipped with a plurality of SIM cards detecting a paging conflict and notifying the base station of the detection. Fig.19 This is a sequence diagram showing a second example of the operation of a UE equipped with a plurality of SIM cards detecting a paging conflict and notifying the base station of the detection. Fig. 20 This is a sequence diagram showing a third example of the operation of a UE equipped with a plurality of SIM cards detecting a paging conflict and notifying a base station of the same, in accordance with the first embodiment. Fig.21 This is a sequence diagram showing a third example of the operation of a UE equipped with a plurality of SIM cards detecting a paging conflict and notifying a base station of the same, in accordance with the first embodiment. Fig. 22 This is a sequence diagram showing an example of the action of a UE equipped with multiple SIM cards detecting a paging conflict and notifying the AMF for implementation mode 1. Fig.23 This is a sequence diagram showing an example of the action of a UE equipped with multiple SIM cards detecting a paging conflict and notifying the AMF for implementation mode 1. Fig.24This is a diagram showing a first example of time division multiplexing of paging in accordance with the first embodiment. Fig.25 This is a diagram showing a second example of time division multiplexing of paging in accordance with the first embodiment. Fig.26 This is an architectural diagram showing an example of connection between a UE equipped with a plurality of SIMs and a plurality of NWs in accordance with Modification 1 of Embodiment 1. Fig. 27 This is a sequence diagram showing a first example of the operation of random access processing between a UE equipped with multiple SIMs and an inactive base station in accordance with Modification 1 of Embodiment 2. Fig.28 This is a sequence diagram showing a first example of the operation of random access processing between a UE equipped with multiple SIMs and an inactive base station in accordance with Modification 1 of Embodiment 2. Fig.29 This is a sequence diagram showing a second example of the operation of random access processing between a UE equipped with multiple SIMs and an inactive base station in accordance with Modification 1 of Embodiment 2. Fig.30 This is a sequence diagram showing a second example of the operation of random access processing between a UE equipped with multiple SIMs and an inactive base station in accordance with Modification 1 of Embodiment 2. Fig.31 This is a sequence diagram showing a third example of the operation of random access processing between a UE equipped with multiple SIMs and an inactive base station in accordance with Modification 1 of Embodiment 2. Fig.32 This is a sequence diagram showing a third example of the operation of random access processing between a UE equipped with multiple SIMs and an inactive base station in accordance with Modification 1 of Embodiment 2. Fig.33 This is a sequence diagram showing a fourth example of the operation of random access processing between a UE equipped with a plurality of SIMs and an inactive base station in accordance with Modification 1 of Embodiment 2. Fig.34 This is a sequence diagram showing a fourth example of the operation of random access processing between a UE equipped with a plurality of SIMs and an inactive base station in accordance with Modification 1 of Embodiment 2. DETAILED DESCRIPTION

[0063] Implementation Method 1 Figure 2 1 is a block diagram showing the overall structure of a communication system 200 of the LTE scheme being discussed in 3GPP. Figure 2The wireless access network is referred to as E-UTRAN (Evolved Universal Terrestrial Radio Access Network) 201. A mobile terminal device (hereinafter referred to as "mobile terminal (User Equipment: UE)") 202 as a communication terminal device can wirelessly communicate with a base station device (hereinafter referred to as "base station (E-UTRAN NodeB: eNB)") 203, and transmit and receive signals using wireless communication.

[0064] Here, the "communication terminal device" refers not only to mobile terminal devices such as mobile phone terminal devices, but also includes non-mobile devices such as sensors. In the following description, the "communication terminal device" may be simply referred to as a "communication terminal".

[0065] If the control protocols for the mobile terminal 202, such as RRC (Radio Resource Control), and the user plane (hereinafter sometimes also referred to as U-Plane), such as PDCP (Packet Data Convergence Protocol), RLC (Radio Link Control), MAC (Medium Access Control), and PHY (Physical layer) are terminated at the base station 203, then the E-UTRAN is composed of one or more base stations 203.

[0066] The control protocol RRC (Radio Resource Control) between the mobile terminal 202 and the base station 203 performs broadcast, paging, RRC connection management, etc. The states of the base station 203 and the mobile terminal 202 in RRC include RRC_IDLE and RRC_CONNECTED.

[0067] In RRC_IDLE, PLMN (Public Land Mobile Network) selection, system information (SI) broadcasting, paging, cell reselection, mobility, etc. are performed. In RRC_CONNECTED, the mobile terminal has an RRC connection and can send and receive data with the network. In addition, in RRC_CONNECTED, handover (HO) and neighbor cell measurement are performed.

[0068] The base station 203 is composed of one or more eNBs 207. In addition, the system composed of the core network, namely EPC (Evolved Packet Core) and the radio access network, namely E-UTRAN 201, is called EPS (Evolved Packet System). Sometimes the core network, namely EPC, and the radio access network, namely E-UTRAN 201, are collectively referred to as "network".

[0069] The eNB 207 is connected to a Mobility Management Entity (MME), or a Serving Gateway (S-GW), or an MME / S-GW unit (hereinafter sometimes referred to as an "MME unit") 204 including an MME and an S-GW via an S1 interface, and control information is communicated between the eNB 207 and the MME unit 204. One eNB 207 can be connected to a plurality of MME units 204. The eNBs 207 are connected to each other via an X2 interface, and control information is communicated between the eNBs 207.

[0070] The MME unit 204 is an upper device, specifically, an upper node, and controls the connection between the base station, namely, the eNB 207, and the mobile terminal (UE) 202. The MME unit 204 constitutes the core network, namely, the EPC. The base station 203 constitutes the E-UTRAN 201.

[0071] The base station 203 may constitute one cell or multiple cells. Each cell has a predetermined range as a range in which communication with the mobile terminal 202 can be performed, i.e., a coverage range, and wireless communication is performed with the mobile terminal 202 within the coverage range. When one base station 203 constitutes multiple cells, each cell is configured to be able to communicate with the mobile terminal 202.

[0072] Figure 3 2 is a block diagram showing the overall structure of a 5G communication system 210 being discussed in 3GPP. Figure 3 For explanation. The wireless access network is called NG-RAN (Next Generation Radio Access Network) 211. UE 202 can wirelessly communicate with the NR base station device (hereinafter referred to as "NR base station (NG-RAN NodeB: gNB)") 213 to send and receive signals in the form of wireless communication. In addition, the core network is called 5G Core (5G Core: 5GC).

[0073] If the control protocols for UE202, such as RRC (Radio Resource Control), and the user plane (hereinafter sometimes also referred to as U-Plane), such as SDAP (Service Data Adaptation Protocol), PDCP (Packet Data Convergence Protocol), RLC (Radio Link Control), MAC (Medium Access Control), and PHY (Physical layer) are terminated at the NR base station 213, then the NG-RAN is composed of one or more NR base stations 213.

[0074] The function of the control protocol RRC (Radio Resource Control) between UE202 and NR base station 213 is the same as that of LTE. The states of NR base station 213 and UE202 in RRC include RRC_IDLE, RRC_CONNECTED, and RRC_INACTIVE.

[0075] RRC_IDLE and RRC_CONNECTED are the same as LTE. In RRC_INACTIVE, the connection between the 5G core and the NR base station 213 is maintained, and broadcasting of system information (SI), paging, cell reselection, movement, etc. are performed.

[0076] gNB217 is connected to the access / mobility management function (Access and Mobility Management Function: AMF), session management function (Session Management Functio: SMF), or UPF (User Plane Function), or the AMF / SMF / UPF unit (hereinafter sometimes referred to as "5GC unit") 214 including AMF, SMF and UPF through the NG interface. Communication of control information and / or user data is performed between gNB217 and the 5GC unit 214. The NG interface is a general term for the N2 interface between gNB217 and AMF, the N3 interface between gNB217 and UPF, the N11 interface between AMF and SMF, and the N4 interface between UPF and SMF. One gNB217 can be connected to multiple 5GC units 214. The gNB217s are connected to each other through the Xn interface, and communication of control information and / or user data is performed between the gNB217s.

[0077] The NR base station 213 is also the same as the base station 203 and can constitute one or more cells. When one NR base station 213 constitutes multiple cells, each cell is configured to communicate with the UE 202.

[0078] gNB217 can be divided into a central unit (Central Unit; sometimes referred to as CU below) 218 ​​and a distributed unit (Distributed Unit: sometimes referred to as DU below) 219. CU218 is configured as one in gNB217. DU219 is configured as one or more in gNB217. CU218 is connected to DU219 via an F1 interface, and control information and / or user data are communicated between CU218 and DU219.

[0079] In the 5G communication system, the Unified Data Management (UDM) function and the Policy Control Function (PCF) described in Non-Patent Document 22 (3GPP TS23.501V16.1.0) may be included. UDM and / or PCF may be included in Figure 3 In the 5GC department.

[0080] In a 5G communication system, a non-3GPP interworking function (N3IWF) described in non-patent document 22 (3GPP TS23.501 V16.1.0) may be included. In a non-3GPP access between the UE and the N3IWF, the access network (AN) may be terminated between the UE and the N3IWF.

[0081] Figure 4 This is a diagram showing the structure of DC based on eNB and gNB connected to EPC. Figure 4 In the figure, the solid line indicates the connection of U-Plane, and the dotted line indicates the connection of C-Plane. Figure 4 In this example, eNB 223-1 is the primary base station and gNB 224-2 is the secondary base station (this DC structure is sometimes referred to as EN-DC). Figure 4 , an example is shown in which the U-Plane connection between the MME unit 204 and the gNB 224-2 is performed via the eNB 223-1, but it can also be performed directly between the MME unit 204 and the gNB 224-2.

[0082] Figure 5 This is a diagram showing the structure of DC based on gNB connected to the NG core. Figure 5 In the figure, the solid line indicates the connection of U-Plane, and the dotted line indicates the connection of C-Plane. Figure 5 In this example, eNB 224-1 is the primary base station and gNB 224-2 is the secondary base station (this DC structure is sometimes referred to as NR-DC). Figure 5 In the figure, an example is shown in which the U-Plane connection between the 5GC unit 214 and the gNB 224-2 is performed via the gNB 224-1, but it can also be performed directly between the 5GC unit 214 and the gNB 224-2.

[0083] Figure 6 This is a diagram showing the structure of DC based on eNB and gNB connected to the NG core. Figure 6 In the figure, the solid line indicates the connection of U-Plane, and the dotted line indicates the connection of C-Plane. Figure 6 In this example, eNB 226-1 is the primary base station and gNB 224-2 is the secondary base station (this DC structure is sometimes referred to as NG-EN-DC). Figure 6 In the figure, an example is shown in which the U-Plane connection between the 5GC unit 214 and the gNB 224-2 is performed via the eNB 226-1, but it can also be performed directly between the 5GC unit 214 and the gNB 224-2.

[0084] Figure 7This is a diagram showing another structure of DC based on eNB and gNB connected to the NG core. Figure 7 In the figure, the solid line indicates the connection of U-Plane, and the dotted line indicates the connection of C-Plane. Figure 7 In the example, gNB 224-1 is the primary base station and eNB 226-2 is the secondary base station (this DC structure is sometimes referred to as NE-DC). Figure 7 , an example is shown in which the U-Plane connection between the 5GC unit 214 and the eNB 226-2 is performed via the gNB 224-1, but it can also be performed directly between the 5GC unit 214 and the eNB 226-2.

[0085] Figure 8 Yes means Figure 2 The structure of the mobile terminal 202 is shown in FIG. Figure 8 The transmission processing of the mobile terminal 202 shown in the figure is explained. First, the control data from the protocol processing unit 301 and the user data from the application unit 302 are stored in the transmission data buffer unit 303. The data stored in the transmission data buffer unit 303 is transmitted to the encoder unit 304 for encoding processing such as error correction. There may also be data that is directly output from the transmission data buffer unit 303 to the modulation unit 305 without performing encoding processing. The data after encoding processing by the encoder unit 304 is modulated in the modulation unit 305. Precoding in MIMO may also be performed in the modulation unit 305. After the modulated data is converted into a baseband signal, it is output to the frequency conversion unit 306 and converted into a wireless transmission frequency. Thereafter, the transmission signal is sent from the antennas 307-1 to 307-4 to the base station 203. In Figure 8 , the example shows a case where the number of antennas is 4, but the number of antennas is not limited to 4.

[0086] In addition, the receiving process of the mobile terminal 202 is performed as follows. The wireless signal from the base station 203 is received through the antennas 307-1 to 307-4. The received signal is converted from the wireless receiving frequency to a baseband signal by the frequency conversion unit 306 and demodulated in the demodulation unit 308. In the demodulation unit 308, waiting calculation and multiplication processing can be performed. The demodulated data is transmitted to the decoder unit 309 for decoding processing such as error correction. Among the decoded data, the control data is transmitted to the protocol processing unit 301, and the user data is transmitted to the application unit 302. A series of processing of the mobile terminal 202 is controlled by the control unit 310. Therefore, although in Figure 8 Although omitted in FIG. 3 , the control unit 310 is connected to each of the units 301 to 309. Figure 8 In the present invention, the number of antennas used by the mobile terminal 202 for sending may be the same as or different from the number of antennas used for receiving.

[0087] Fig. 9 Yes means Figure 2 The structure of the base station 203 is shown in FIG. Fig. 9 The sending processing of the base station 203 shown is explained. The EPC communication unit 401 performs data transmission and reception between the base station 203 and the EPC (MME unit 204, etc.). The 5GC communication unit 412 performs data transmission and reception between the base station 203 and the 5GC (5GC unit 214, etc.). The other base station communication units 402 perform data transmission and reception with other base stations. The EPC communication unit 401, the 5GC communication unit 412 and the other base station communication units 402 exchange information with the protocol processing unit 403 respectively. The control data from the protocol processing unit 403, and the user data and control data from the EPC communication unit 401, the 5GC communication unit 412 and the other base station communication units 402 are saved in the sending data buffer unit 404.

[0088] The data stored in the transmission data buffer unit 404 is transmitted to the encoder unit 405 for encoding processing such as error correction. There may also be data that is directly output from the transmission data buffer unit 404 to the modulation unit 406 without performing encoding processing. The encoded data is modulated in the modulation unit 406. Precoding in MIMO may also be performed in the modulation unit 406. After the modulated data is converted into a baseband signal, it is output to the frequency conversion unit 407 and converted into a wireless transmission frequency. Thereafter, the transmission signal is sent to one or more mobile terminals 202 using antennas 408-1 to 408-4. Fig. 9 , the example shows a case where the number of antennas is 4, but the number of antennas is not limited to 4.

[0089] In addition, the receiving processing of the base station 203 is performed as follows. The wireless signal from one or more mobile terminals 202 is received through the antenna 408. The received signal is converted from the wireless receiving frequency to a baseband signal by the frequency conversion unit 407, and demodulated in the demodulation unit 409. The demodulated data is transmitted to the decoder unit 410 for decoding processing such as error correction. Among the decoded data, the control data is transmitted to the protocol processing unit 403 or the 5GC communication unit 412 or the EPC communication unit 401, and other base station communication units 402, and the user data is transmitted to the 5GC communication unit 412, the EPC communication unit 401 and other base station communication units 402. A series of processing of the base station 203 is controlled by the control unit 411. Therefore, although in Fig. 9 Although omitted in FIG. 4 , the control unit 411 is connected to each unit 401 to 410. Fig. 9 In the example, the number of antennas used by the base station 203 for sending may be the same as or different from the number of antennas used for receiving.

[0090] Fig. 92 is a block diagram showing the structure of the base station 203, but the same structure can be used for the base station 213. Figure 8 and Fig. 9 , the number of antennas of the mobile terminal 202 and the number of antennas of the base station 203 may be the same or different.

[0091] Fig.10 It is a block diagram showing the structure of MME. Fig.10 The above Figure 2 The structure of MME204a included in the MME unit 204 shown. The PDN GW communication unit 501 transmits and receives data between the MME204a and the PDN GW. The base station communication unit 502 transmits and receives data between the MME204a and the base station 203 using the S1 interface. When the data received from the PDN GW is user data, the user data is transmitted from the PDN GW communication unit 501 to the base station communication unit 502 via the user plane communication unit 503, and is sent to one or more base stations 203. When the data received from the base station 203 is user data, the user data is transmitted from the base station communication unit 502 to the PDN GW communication unit 501 via the user plane communication unit 503, and is sent to the PDN GW.

[0092] When the data received from the PDN GW is control data, the control data is transmitted from the PDN GW communication unit 501 to the control plane control unit 505. When the data received from the base station 203 is control data, the control data is transmitted from the base station communication unit 502 to the control plane control unit 505.

[0093] The control plane control unit 505 includes a NAS security unit 505-1, an SAE bearer control unit 505-2, an idle state mobility management unit 505-3, etc., and performs all processing for the control plane (hereinafter, sometimes also referred to as C-Plane). The NAS security unit 505-1 is responsible for the security of NAS (Non-Access Stratum) messages, etc. The SAE bearer control unit 505-2 manages SAE (System Architecture Evolution) bearers, etc. The idle state mobility management unit 505-3 performs mobility management in the standby state (also called idle state; LTE-IDLE state, or simply idle), generation and control of paging signals in the standby state, addition, deletion, update, retrieval, and tracking area list management of the tracking areas of one or more covered mobile terminals 202, etc.

[0094] MME204a distributes paging signals to one or more base stations 203. In addition, MME204a performs mobility control in the idle state. MME204a manages the tracking area list when the mobile terminal is in the idle state and the active state. MME204a starts the paging protocol by sending a paging message to the cell belonging to the tracking area (Tracking Area) where the UE is registered. The management of the CSG of the eNB207 connected to MME204a, the management of the CSG ID and the management of the whitelist can also be performed by the idle state mobility management unit 505-3.

[0095] Fig.11 It is a block diagram showing the structure of 5GC. Fig.11 The above Figure 3 The structure of the 5GC unit 214 is shown. Fig.11 Shown in Figure 5 The 5GC unit 214 shown includes the structure of AMF, the structure of SMF, and the structure of UPF. The data network communication unit 521 performs data transmission and reception between the 5GC unit 214 and the data network. The base station communication unit 522 performs data transmission and reception between the 5GC unit 214 and the base station 203 through the S1 interface, and / or performs data transmission and reception between the 5GC unit 214 and the base station 213 through the NG interface. In the case where the data received from the data network is user data, the user data is transmitted from the data network communication unit 521 to the base station communication unit 522 via the user plane communication unit 523, and is sent to one or more base stations 203 and / or base stations 213. In the case where the data received from the base station 203 and / or the base station 213 is user data, the user data is transmitted from the base station communication unit 522 to the data network communication unit 521 via the user plane communication unit 523, and is sent to the data network.

[0096] When the data received from the data network is control data, the control data is transmitted from the data network communication unit 521 to the session management unit 527 via the user plane control unit 523. The session management unit 527 transmits the control data to the control plane control unit 525. When the data received from the base station 203 and / or the base station 213 is control data, the control data is transmitted from the base station communication unit 522 to the control plane control unit 525. The control plane control unit 525 transmits the control data to the session management unit 527.

[0097] The control plane control unit 525 includes a NAS security unit 525-1, a PDU session control unit 525-2, an idle state (IdleState) mobility management unit 525-3, etc., and performs all processing for the control plane (hereinafter, sometimes also referred to as C-Plane). The NAS security unit 525-1 is responsible for the security of NAS (Non-Access Stratum: non-access layer) messages, etc. The PDU session control unit 525-2 manages the PDU session between the mobile terminal 202 and the 5GC unit 214, etc. The idle state mobility management unit 525-3 performs mobility management in the standby state (also called the idle state (Idle State); RRC-IDLE state, or simply idle), generation and control of paging signals in the standby state, addition, deletion, update, retrieval, and tracking area list management of the tracking area of ​​one or more covered mobile terminals 202, etc.

[0098] The 5GC unit 214 allocates paging signals to one or more base stations 203 and / or base stations 213. In addition, the 5GC unit 214 performs mobility control in the idle state. The 5GC unit 214 manages the tracking area list when the mobile terminal is in the idle state, in the inactive state, and in the active state. The 5GC unit 214 starts the paging protocol by sending a paging message to the cell belonging to the tracking area registered by the UE.

[0099] Next, an example of a cell search method in a communication system is shown. Fig.12 This is a flowchart of the overview of the cell search and standby operation performed by a communication terminal (UE) in an LTE communication system. After starting the cell search, the communication terminal uses the first synchronization signal (P-SS) and the second synchronization signal (S-SS) sent from the surrounding base stations to obtain the synchronization of the time slot timing and the frame timing in step ST601.

[0100] P-SS and S-SS are collectively referred to as synchronization signals (SS). Synchronization codes corresponding to PCIs assigned to each cell are allocated to the synchronization signal (SS). The number of PCIs is set to 504. Synchronization is achieved using these 504 PCIs, and the PCI of the synchronized cell is detected (determined).

[0101] Next, in step ST602, the reference signal (reference signal: RS) sent from the base station to each cell, i.e., the cell-specific reference signal (Cell-specific Reference Signal: CRS), is detected for the synchronized cell, and the RS received power (Reference Signal Received Power: RSRP) is measured. The reference signal (RS) uses a code that corresponds to the PCI one-to-one. This code can be used to obtain correlation and separate from other cells. By deriving the RS code for the cell from the PCI determined in step ST601, the RS can be detected and the RS received power can be measured.

[0102] Next, in step ST603, a cell with the best RS reception quality, for example, a cell with the highest RS reception power, that is, an optimal cell, is selected from the one or more cells detected up to step ST602.

[0103] Next, in step ST604, the PBCH of the best cell is received to obtain the broadcast information, i.e., the BCCH. The MIB (Master Information Block) containing the cell structure information is mapped in the BCCH on the PBCH. Therefore, by receiving the PBCH and obtaining the BCCH, the MIB can be obtained. The information of the MIB includes, for example, the DL (downlink) system bandwidth (also called the transmission bandwidth configuration (transmission bandwidth configuration: dl-bandwidth)), the number of transmitting antennas, and the SFN (System Frame Number: system frame number).

[0104] Then in step ST605, the DL-SCH of the cell is received based on the cell structure information of the MIB, and the SIB (System Information Block) 1 in the broadcast information BCCH is obtained. SIB1 contains information related to accessing the cell, information related to cell selection, and scheduling information of other SIBs (SIBk; k≧2 integer). In addition, SIB1 contains the Tracking Area Code (TAC).

[0105] Next, in step ST606, the communication terminal compares the TAC of SIB1 received in step ST605 with the TAC part of the tracking area identity (TAI) in the tracking area list that the communication terminal has saved. The tracking area list is also called the TAI list. TAI is identification information for identifying the tracking area, and is composed of MCC (Mobile Country Code), MNC (Mobile Network Code), and TAC (Tracking Area Code). MCC is the country code. MNC is the network code. TAC is the code number of the tracking area.

[0106] If the result of the comparison in step ST606 is that the TAC received in step ST605 is the same as the TAC included in the tracking area list, the communication terminal enters the standby action in the cell. If the result of the comparison is that the TAC received in step ST605 is not included in the tracking area list, the communication terminal requests the core network (CoreNetwork, EPC) including MME, etc. to change the tracking area through the cell to perform TAU (Tracking Area Update).

[0107] exist Fig.12 In the example shown, an example of the action from cell search to standby in the LTE mode is shown, but in the NR mode, in addition to the best cell, the best beam can also be selected in step ST603. In addition, in the NR mode, in step ST604, beam information such as a beam identifier can be obtained. In addition, in the NR mode, in step ST604, scheduling information of the remaining minimum SI (Remaining Minimum SI: RMSI) can be obtained. In the NR mode, in step ST605, it can be set to receive RMSI.

[0108] The device constituting the core network (hereinafter sometimes referred to as the "core network side device") updates the tracking area list based on the identification number (UE-ID, etc.) of the communication terminal sent from the communication terminal together with the TAU request signal. The core network side device sends the updated tracking area list to the communication terminal. The communication terminal rewrites (updates) the TAC list held by the communication terminal based on the received tracking area list. Thereafter, the communication terminal enters standby action in the cell.

[0109] As smartphones and tablet devices become more common, the volume of cellular wireless communications has exploded, leading to concerns about the shortage of wireless resources worldwide. In response to this, research is being conducted on miniaturization of cells and promotion of spatial separation to improve frequency utilization efficiency.

[0110] In the existing cell structure, a cell formed by an eNB has a wide coverage area. Conventionally, cells are formed to cover a certain area by utilizing the wide coverage areas of a plurality of cells formed by a plurality of eNBs.

[0111] In the case of small cellization, the cell formed by the eNB has a coverage area narrower than the coverage area of ​​the cell formed by the existing eNB. Therefore, as in the prior art, in order to cover a certain area, a large number of small cell eNBs are required compared with the existing eNBs.

[0112] In the following description, a cell with a relatively large coverage area, such as a cell formed by conventional eNBs, is referred to as a "macro cell", and an eNB constituting a macro cell is referred to as a "macro eNB". In addition, a cell with a relatively small coverage area, such as a cell after cell miniaturization, is referred to as a "small cell cell", and an eNB constituting a small cell is referred to as a "small eNB".

[0113] The macro cell eNB may be, for example, the “Wide Area Base Station” described in Non-Patent Document 7.

[0114] Small cell eNBs are, for example, low-power nodes, local area nodes, and hotspots. In addition, small cell eNBs may also be pico eNBs constituting pico cells, femto eNBs constituting femto cells, HeNBs, RRHs (Remote Radio Heads), RRUs (Remote Radio Units), RREs (Remote Radio Equipment), or RNs (Relay Nodes). In addition, small cell eNBs may be "local area base stations" or "home base stations" as described in non-patent document 7.

[0115] Fig.13 An example of a cell structure in NR is shown. In a cell in NR, a narrow beam is formed and its direction is changed for transmission. Fig.13In the example shown, the base station 750 uses beam 751-1 at a certain time to transmit and receive with the mobile terminal. At other times, the base station 750 uses beam 751-2 to transmit and receive with the mobile terminal. Similarly, the base station 750 uses one or more of beams 751-3 to 751-8 to transmit and receive with the mobile terminal. Thus, the base station 750 forms a wide range of cells.

[0116] exist Fig.13 In FIG. 1 , an example is shown in which the number of beams used by the base station 750 is set to 8, but the number of beams may be different from 8. Fig.13 In the example shown, the number of beams used simultaneously by the base station 750 is set to one, but it can also be multiple.

[0117] The UE can be connected to multiple NWs or in a connectable state (hereinafter, "connection" sometimes includes not only the state of actual connection but also the state of connectable). The UE can use multiple SIM cards to connect to the multiple NWs. The UE can have only one set of transceivers or multiple sets of transceivers. The multiple NWs can be PLMNs or non-public networks (NPN). Connections to the multiple NWs can be performed in parallel.

[0118] For the connection between the UE and each NW, the RRC state of the UE can be the RRC_CONNECTED state, the RRC_INACTIVE state, or the RRC_IDLE state. The CM state of the UE can be the CM-IDLE state or the CM-CONNECTED state. The UE can be in the RRC_CONNECTED state or the CM-CONNECTED state for more than two of the multiple NWs of the connection target. As another example, the UE can be in the RRC_CONNECTED state or the CM-CONNECTED state for only one of the multiple NWs of the connection target.

[0119] Fig.14 This is an architectural diagram showing an example of connection between a UE equipped with multiple SIMs (hereinafter sometimes referred to as a UE equipped with multiple SIMs (Multi-SIM UE)) and multiple NWs. Fig.14 In the example, a UE equipped with multiple SIM cards is connected in parallel to PLMN#1 and PLMN#2.

[0120] exist Fig.14In the example shown, UE1400 is connected to gNB1401 in PLMN#1. In addition, UE1400 is connected to gNB1411 in PLMN#2. gNB1401 is connected to AMF1402 and UPF1403 in PLMN#1. SMF1404 in PLMN#1 is connected to AMF1402 and UPF1403. gNB1411 is connected to AMF1412 and UPF1413 in PLMN#2. SMF1414 in PLMN#2 is connected to AMF1412 and UPF1413.

[0121] Although in Fig.14 The example shown shows a case where UE 1400 is connected to two PLMNs, but UE 1400 may also be connected to more than three PLMNs. In addition, one or more of the two NWs to which UE 1400 is connected may also be NPNs. The same is true when UE 1400 is connected to more than three NWs.

[0122] In a UE connected in parallel to multiple NWs, paging timing may overlap (hereinafter sometimes referred to as paging conflict). The UE in which the paging conflict occurs may be a UE having only one set of transceivers. In this case, no specific method for avoiding the paging conflict is disclosed. Therefore, the devices of the communication system cannot avoid paging the UE. As a result, the problem of the UE being unable to receive paging from the above one or more NWs occurs.

[0123] In the first embodiment, a method for solving the above-mentioned problem is disclosed.

[0124] The UE detects a conflict of paging from multiple NWs. The UE may perform the detection using the frame timing in each NW and the related timing of paging (hereinafter, sometimes referred to as paging timing). The UE may determine that a conflict of paging has occurred when the related timing of paging in multiple NWs repeats in actual time. The UE may correct the paging timing in each NW using the frame timing in each NW. The UE may perform the detection using the corrected paging timing. The UE performs the detection using the frame timing, so that, for example, a conflict of paging can be detected even when the frame timing of each NW is different.

[0125] UE can use cell search to obtain frame timing in the base station of each NW. UE can use system information notified from the base station of each NW and the identifier of the UE allocated to the UE from each NW to obtain the relevant timing of paging in each NW. The timing related to paging can be PF (Paging Frame), PO (Paging Occasion), PDCCH monitoring occasion for paging reception, or a combination of multiple of the above.

[0126] In the detection of paging conflicts, the UE may use PF, PO, PDCCH monitoring timing, or multiple of the above. For example, the UE uses PF in the detection, thereby reducing the amount of processing associated with the detection. As another example, the UE may use a combination of PF, PO, and PDCCH monitoring timing in the detection, thereby improving the accuracy of the detection.

[0127] Fig.15 An example of paging conflict from multiple NWs is shown. Fig.15 A case where the UE is connected to NW#1 and NW#2 is shown. Fig.15 , the horizontal axis represents time.

[0128] exist Fig.15 At the time of arrow 1501 , the SFN of NW#1 becomes 0. At the time of arrow 1502 , the SFN of NW#2 becomes 0. The paging timing of the UE in NW#1 is arranged in interval 1505 , and the paging timing of the UE in NW#2 is arranged in interval 1506 .

[0129] exist Fig.15 In the example shown, the interval 1505 and the interval 1506 overlap in time in the interval 1508 indicated by the dotted line. In this case, the UE determines that a paging conflict has occurred.

[0130] exist Fig.15 In the example shown, the paging timing may be a PF (Paging Frame), a PO (Paging Occasion), a PDCCH monitoring occasion for paging reception, or a combination of the above.

[0131] As another example of paging conflict detection at the UE, when the period of N periods of the SS burst period at the base station of one NW overlaps with the paging timing at the base station of another NW, it can be assumed that a paging conflict has occurred. The above N can be 0, 1, or more than 2. The above N can be determined by the standard or by the UE. The above N can be determined by a base station, for example, a base station that sends the paging received by the UE and notified to the UE. As a result, for example, the UE can establish downlink synchronization with the base station that sends the paging. As a result, the UE can quickly obtain the paging.

[0132] The UE notifies the NW of the paging conflict. The UE may include information required to avoid the paging conflict in the notification. The UE may request the NW to avoid the paging conflict. The request may include the above information.

[0133] The UE may make the notification to the base station. For example, the UE may make the notification to a base station with an earlier PRACH transmission timing among the base stations of the multiple NWs. Thus, for example, the UE can quickly connect to any one of the multiple NWs, and as a result, paging conflicts can be quickly avoided.

[0134] The UE may make the notification to the base station of one NW. Thus, for example, in the communication system, paging conflicts can be avoided with less signaling. As another example, the UE may make the notification to the base stations of multiple NWs. Thus, for example, in the communication system, the flexibility of paging timing changes can be improved.

[0135] The UE may use RRC signaling to make the notification. For example, the UE may use an RRC setup request (RRCSetupRequest) in the notification. Thus, for example, the UE can quickly perform the notification to the base station. As another example, the UE may use an RRC setup completion (RRCSetupComplete) in the notification. Thus, for example, the UE can include more information to notify the base station.

[0136] As another example, the UE may use an RRC resume request (RRCResumeRequest) in the notification. Thus, for example, the UE can quickly perform the notification to the base station. As another example, the UE may use an RRC resume complete (RRCResumeComplete) in the notification. Thus, for example, the UE can include more information to notify the base station.

[0137] As another example, the UE may use RRCReconfigurationComplete in the notification. Thus, the UE can include more information to notify the base station.

[0138] As another example, new RRC signaling may be set, for example, a signaling as an RRC reconfiguration request (RRC ReconfigurationRequest) may be set and used, or a signaling as a paging collision notification (PagingCollisionNotification) may be set and used.

[0139] As another example of notification from the UE to the base station, MAC signaling may be used. Thus, for example, the UE can quickly notify of a paging conflict. As another example, L1 / L2 signaling may be used. Thus, for example, the UE can more quickly notify of a paging conflict.

[0140] The UE may include information related to the presence or absence of a paging conflict in the notification. The information may be, for example, an identifier of the presence or absence of a paging conflict. Thus, for example, the UE may notify the paging conflict with less signaling.

[0141] The UE may include information for avoiding paging conflicts in the notification. As examples of information for avoiding paging conflicts, the following (1) to (10) are disclosed.

[0142] (1) Information related to other NW logos.

[0143] (2) Information related to the paging timing of other NWs.

[0144] (3) Information related to parameter sets in other NWs.

[0145] (4) Information related to the frame timing of other NWs.

[0146] (5) Information used to derive the paging timing of other NWs.

[0147] (6) Information related to the beam used for communication with the notification target NW.

[0148] (7) Information related to synchronization signals of other NWs.

[0149] (8) Information related to the Radio Access Technology (RAT) of other NWs.

[0150] (9) Information related to the use of multiple SIM cards of this UE.

[0151] (10) A combination of the above (1) to (9).

[0152] The information in (1) above may be, for example, the PLMN-ID of the other NW, may include the NPN-ID disclosed in Non-Patent Document 23 (TR23.734), or may include the CAG-ID. Thus, for example, the base station can grasp the NW for which paging conflicts are to be avoided, and as a result, the complexity of the avoidance process can be avoided.

[0153] As another example of the information in (1) above, an identifier that uniquely identifies the UE may be used. The identifier may be, for example, a 5G-GUTI (5G Globally Unique Temporary Identifier). The base station may extract the PLMN-ID of the other NW from the 5G-GUTI. Thus, for example, the base station may simultaneously obtain the identifier of the other NW and the identifier of the UE. As a result, the base station is able to obtain information for deriving paging timing in other NWs with less signaling.

[0154] The information in (2) above may be, for example, a PF (Paging Frame) in another NW, a PO (Paging Occasion), a PDCCH monitoring occasion for paging reception, or a combination of the above. This can reduce the amount of paging conflict avoidance processing performed by the base station, for example.

[0155] As another example, the information in (2) above may include information related to the moment of paging timing in other NWs. The information related to the moment may include, for example, the moment at the starting point of the paging timing, may include the moment related to the end point of the paging timing, may include information related to the duration of the paging timing, or may include multiple of the above information. The paging timing may be a PF (Paging Frame) in other NWs, or a PO (Paging Occasion), or a PDCCH monitoring occasion for paging reception, or a combination of multiple of the above. Thus, for example, the amount of processing performed by the base station for paging conflict avoidance can be reduced.

[0156] The information in (3) above may be, for example, the subcarrier spacing, slot length or symbol length used by the UE in receiving paging from other NWs, or the parameter μ disclosed in Section 4.2 of Non-Patent Document 13 (TS38.211). This can improve the reliability of paging conflict avoidance performed by the base station, for example.

[0157] The information in (4) above may be, for example, information on the difference in frame timing between the target base station and base stations of other NWs provided in SFN units, subframe units, time slot units, symbol units, or the minimum unit in the communication system (e.g., Ts units), or a combination thereof. The time slot in the above text may be a time slot in the target base station or a time slot in other NWs. Thus, for example, the amount of processing for avoiding paging conflicts performed by the base station can be reduced.

[0158] As another example, the information in (4) above may be a specified time point in another NW, for example, a time at a boundary of a specified SFN. The boundary may be the head of the SFN or the end of the SFN. As another example, it may be a time at a specified subframe boundary, a time at a specified time slot boundary, or a time at a specified symbol boundary. The UE may obtain the information by searching the cell of the other NW or may obtain the information from the notification information from the other NW. Thus, for example, the amount of processing required for the notification of the UE may be reduced.

[0159] The information in (5) above may include, for example, the identifier of the UE at another NW, and may also include parameters in the other NW for determining the paging timing. The parameters may include part or all of the notification information from the base station of the NW, for example, the PCCH setting information (PCCH-Config) disclosed in non-patent document 4 (TS38.331). Thus, for example, the amount of processing required for the notification from the UE can be reduced.

[0160] The above-mentioned identifier related to the information in (5) above can be, for example, the UE_ID disclosed in Section 7.1 of non-patent document 25 (TS38.304), or the 5G-S-TMSI (5G S-TemporaryMobile Subscription Identifier: 5G S-temporary mobile subscription identifier), 5G-TMSI (5G TemporaryMobile Subscription Identifier: 5G temporary mobile subscription identifier) ​​or 5G-GUTI disclosed in non-patent document 22 (TS23.501).

[0161] The above parameters related to the information in (5) above may include the DRX (Discontinuous Reception) cycle (T) of the UE disclosed in non-patent document 25 (TS38.304), may include the total count of paging frames in the cycle (N), may include the number of paging occasions in PF (Ns), may include the offset used in PF determination (PF_offset), and may include the initial PDCCH monitoring occasion in PO (first-PDCCH-MonitoringOccasionOfPO).

[0162] The information in (6) above may also be information related to the beam used by the UE when receiving from the notification target base station. The beam may be information related to the beam used by the UE when receiving the SS block from the base station, or may be information related to the beam used by the UE when receiving notification information, such as SIB1 or RMSI (Remaining Minimum System Information) from the base station. The base station may use the information in (6) above to change the paging timing in the beam where the UE is located. The base station may change the notification information in the beam. Thus, for example, the base station can flexibly change the paging timing.

[0163] The information in (7) above may be, for example, information related to the period of the SS burst, or the duration of the SS block transmission in one period of the SS burst. The base station may use the information in (7) above to, for example, avoid setting the paging timing by avoiding multiple SS burst periods transmitted from base stations of other NWs, or may set the paging timing by avoiding the duration of the SS block transmission. The UE may use the information to receive the synchronization signal of the base station of other NWs. The UE may receive the paging after receiving the synchronization signal. Thus, for example, the timing deviation in the paging reception of the UE may be prevented.

[0164] The information in (8) above may be, for example, information indicating that the base station of the other NW is an NR base station, or information indicating that the base station of the other NW is an LTE base station. The base station may use this information to change the paging timing. For example, when the base station of the other NW is an LTE base station, for example, when the paging timing in the LTE base station is fixed, the base station may change the period of the paging timing. Thus, for example, the possibility of failure to avoid paging conflicts in the communication system may be reduced.

[0165] The information in (9) above may be, for example, information indicating whether the UE is a UE equipped with multiple SIMs, or information related to the use of multiple SIMs. The information related to the use of multiple SIMs may include, for example, the number of transmitters and / or receivers at the UE, the number of NWs to which the UE can connect, and the number of RRCs that the UE can maintain. The information related to the use of multiple SIMs may be information related to a combination of RRC states at the UE, for example, information indicating whether multiple base stations among the base stations of multiple NWs can become RRC_CONNECTED at the same time. The UE may include this information, for example, in the UE capabilities to notify the base station. The base station may use this information to send and receive data with the UE. As a result, for example, the efficiency in the communication system can be improved.

[0166] The base station can use the notification from the UE to change the paging timing. For example, the base station can change the parameter used to determine the paging timing. The parameter can be, for example, the above-mentioned parameter related to the above-mentioned (5) information. The base station can notify the subordinate UE of the changed parameter. For example, the base station can also include the changed parameter in SIB1 for notification. The UE can use the notification to change the timing of receiving paging (hereinafter sometimes referred to as paging reception timing).

[0167] The UE may receive paging from a base station that is a notification target of the information in priority to paging from base stations of other NWs. For example, the UE may receive priority paging until the UE receives paging parameters changed at the base station from the base station. Thus, for example, the UE can quickly acquire the changed paging parameters.

[0168] The base station can change the parameter for each beam. The notification information from the base station can be different for each beam. This can improve the flexibility of the parameter setting in the communication system, for example.

[0169] As another example, the base station may change the parameter separately for each UE. The base station may notify the UE of the changed parameter separately for each UE. The base station may include the changed parameter in RRC signaling, such as RRC reconfiguration, and notify the UE separately. The UE may use the separate notification to change the paging reception timing. Thus, for example, in the communication system, the complexity of the processing related to the change of the paging timing may be avoided.

[0170] As another example, the base station may uniformly set or uniformly change the parameter for multiple UEs. For example, the base station may uniformly set and / or change the parameter for multiple UEs equipped with multiple SIMs. For example, the multiple UEs equipped with multiple SIMs may also be all UEs equipped with multiple SIMs covered by the base station. For example, the NW connection targets of the multiple UEs equipped with multiple SIMs other than the base station may be the same or different. The multiple UEs equipped with multiple SIMs may also be treated as a UE group. The base station sets and / or changes the parameter for the UE group.

[0171] The base station may uniformly notify the multiple UEs of the parameter uniformly set and / or changed for the multiple UEs. The notification may, for example, utilize RRC signaling. A specific UE-ID, such as a multicast UE-ID, may be set in the unified notification. The multiple UEs may use the unified notification to set and / or change the parameter. Thus, for example, the amount of signaling between the base station and the multiple UEs may be reduced.

[0172] The above-mentioned unified notification from the base station to the multiple UEs can be performed in other RRC signaling. Thus, for example, the amount of signaling between the base station and the multiple UEs can be further reduced.

[0173] The UE may notify the base station of the other NW of the changed parameter notified by the base station. The UE may include information related to the UE's identity in the notification to the base station of the other NW. The identity may also be an identity allocated in the NW of the base station that changed the parameter. The base station of the other NW may use the parameter to change the paging timing in the other NW, or may not change it. Thus, for example, the paging timing in the other NW may be changed by avoiding the notified parameter. As a result, paging conflicts after the paging timing is changed may be prevented.

[0174] Fig.16 and Fig.17 This is a sequence diagram showing a first example of the operation of a UE equipped with multiple SIM cards detecting a paging conflict and notifying a base station of the same. Fig.16 and Fig.17 Connect at the boundary line BL1617. Fig.16 and Fig.17 In the example, the UE is connected to two NWs (NW#1 and NW#2), and is connected to gNB#1 to which NW#1 belongs and gNB#2 to which NW#2 belongs. Fig.16 and Fig.17 In , AMF#1 and AMF#2 exist under the subordinate of NW#1 and NW#2 respectively. Fig.16 and Fig.17 In the example shown, the UE is in RRC_IDLE state for both gNB#1 and gNB#2. Fig.16 and Fig.17 An example is shown in which the UE notifies gNB#1 of a paging conflict.

[0175] exist Fig.16 In step ST1601 shown, gNB#1 sends an SS block to the UE. In step ST1602, gNB#2 sends an SS block to the UE. In step ST1603, the UE obtains the SFN timing of gNB#1 and gNB#2 sent in the above steps ST1601 and ST1602, and derives the difference between the SFN timings of the two gNBs.

[0176] exist Fig.16In step ST1606 shown, gNB#1 notifies the UE of system information. The system information notified in step ST1606 includes parameters related to paging in gNB#1. In step ST1607, gNB#2 notifies the UE of system information. The system information notified in step ST1607 includes parameters related to paging in gNB#2. The parameters notified in steps ST1606 and ST1607 may be parameters of the same type as the parameters included in the information of (5) above disclosed as information for avoiding paging conflicts. In step ST1608, the UE uses the information obtained by the above steps ST1606 and ST1607 to obtain the paging timing at gNB#1 and gNB#2.

[0177] Fig.16 Step ST1611 shown indicates the paging timing for the UE from gNB#1. Step ST1612 indicates the paging timing for the UE from gNB#2. Fig.16 It shows the situation where the paging timing of gNB#1 and gNB#2 conflict with each other.

[0178] exist Fig.16 In step ST1615 shown, the UE determines whether there is a conflict between the paging from gNB#1 and gNB#2. The difference in frame timing obtained in step ST1603 and the paging timing obtained in step ST1608 can be used in this determination. If the UE determines that there is no paging conflict, the processing after step ST1621 may not be performed, and the system information acquisition processing of steps ST1606 and ST1607 may be returned. If the UE determines that a paging conflict is occurring, the processing after step ST1621 is performed.

[0179] Fig.16 Steps ST1621 to ST1629 shown relate to the processing of the UE notifying gNB#1 of a paging conflict. In step ST1621, the UE sends a PRACH to gNB#1. In step ST1623, gNB#1 sends a random access response (Random Access Response; RAR) to the UE.

[0180] exist Fig.16 In step ST1625 shown, the UE requests gNB#1 to establish RRC. For this request, RRC signaling, such as the RRC setup request (RRCSetupRequest) of non-patent document 24 (TS 38.331), can be used. In step ST1627, gNB#1 instructs the UE to establish RRC. For this indication, RRC signaling, such as the RRC setup (RRCSetup) of non-patent document 24 (TS38.331), can be used.

[0181] exist Fig.16 In step ST1629 shown, the UE notifies gNB#1 of the completion of the RRC establishment. For this notification, RRC signaling, such as RRC Setup Complete (RRCSetupComplete) of non-patent document 24 (TS 38.331), can be used. The UE can include information related to paging conflicts in the notification of step ST1629. The information may include, for example, information related to the presence or absence of paging conflicts, and may also include the above-mentioned information (1) to (10) disclosed as examples of information for avoiding paging conflicts.

[0182] exist Fig.17 In step ST1631 shown, gNB#1 changes the paging timing. In step ST1633, gNB#1 notifies the UE of system information. The notification may include parameters related to the changed paging timing. In step ST1635, the UE obtains the paging parameters notified in the above step ST1633 and uses the parameters to obtain the paging timing of gNB#1. The UE changes the paging reception timing of gNB#1 according to the obtained paging timing.

[0183] The UE receives the paging of gNB#1 at the changed paging reception timing of gNB#1. As a result, the UE can receive the paging from gNB#1 and the paging from gNB#2.

[0184] For example, the UE receives paging from gNB#1, and when there is no paging, switches to reception of gNB#2 until the paging timing of gNB#2, and receives paging of gNB#2. In addition, the UE receives paging from gNB#2, and when there is no paging, switches to reception of gNB#1 until the paging timing of gNB#1, and receives paging of gNB#1. For example, the UE can receive paging from gNB#1, and when there is paging, perform processing according to the received paging.

[0185] The base station may request the AMF to change the UE identifier. The base station may execute the request, for example, when a paging conflict cannot be avoided by only changing the parameters used to determine the paging timing in (5) above (for example, PCCH configuration information (PCCH-Config)). When a paging conflict may occur due to the change of the parameter, the base station may not send the request to the AMF. Thus, for example, unnecessary changes to the identifier can be prevented when the paging conflict can be avoided by only changing the PCCH configuration information. The request may include one or more UE identifiers as change candidates. For the request, for example, signaling in the N2 interface may be used. New signaling, such as signaling of an N2 UE configuration update request (N2 UE configuration update request), may be set and used. The UE identifier may be, for example, the UE_ID disclosed in Section 7.1 of non-patent document 25 (TS38.304), or the 5S-TMSI (5G S-Temporary Mobile Subscription Identifier), 5G-TMSI (5G Temporary Mobile Subscription Identifier), or 5G-GUTI disclosed in non-patent document 22 (TS23.501). The AMF may use this signaling to change the UE identifier.

[0186] The base station may notify the AMF of information for avoiding paging conflicts. The base station may include the information in the request for the UE's identity to notify. The information may include the above-mentioned information (1) to (10). The base station may convert the above-mentioned information (1) to (10) notified from the UE into signaling in the N2 interface to notify. The information may further include information related to this NW. The information related to this NW may also be the information after other NWs are replaced with this NW for the above-mentioned information (1) to (10). The AMF may use the information related to this NW to change the UE's identity. Thus, for example, paging conflicts in the changed UE's identity can be prevented.

[0187] The AMF can notify the UE of the changed identity. For this notification, NAS signaling can be used, such as the configuration update indication (CONFIGURATION UPDATE COMMAND) disclosed in non-patent document 27 (TS24.501). The identity can be, for example, the 5G-S-TMSI (5G S-Temporary Mobile Subscription Identifier: 5G S-Temporary Mobile Subscription Identifier) ​​disclosed in non-patent document 22 (TS23.501). The UE can use this notification to update the UE-ID of this UE.

[0188] The UE may notify the AMF of the completion of the identity update of the UE. For this notification, NAS signaling may be used, such as the CONFIGURATION UPDATE COMPLETE disclosed in non-patent document 27 (TS24.501).

[0189] The AMF may notify the base station of the changed identifier. For the notification, signaling on the N2 interface may be used. The base station may use the notification to change the paging timing of the UE. For example, the base station may use the changed identifier of the UE to change the parameter used to determine the paging timing. Thus, for example, the flexibility of the paging timing change in the UE may be improved. Notification of the changed parameter from the base station to the UE may be the same as above.

[0190] Fig.18 and Fig.19 It is a sequence diagram showing the second example of the action in which a UE equipped with multiple SIMs detects a paging conflict and notifies the base station, and the base station requests the AMF for the UE's identification. Fig.18 and Fig.19 Connect at the boundary line BL1819. Fig.18 and Fig.19 In the example, the UE is connected to two NWs (NW#1 and NW#2), and is connected to gNB#1 to which NW#1 belongs and gNB#2 to which NW#2 belongs. Fig.18 and Fig.19 In , AMF#1 and AMF#2 exist under the subordinate of NW#1 and NW#2 respectively. Fig.18 and Fig.19 In the example shown, the UE is in RRC_IDLE state for both gNB#1 and gNB#2. Fig.18 and Fig.19 This shows an example where the UE notifies gNB#1 of a paging conflict and gNB#1 requests AMF#1 to change the UE's identity. Fig.18 and Fig.19 In, with Fig.16 and Fig.17 The same processing is assigned the same step numbers, and common descriptions are omitted.

[0191] Fig.18 Steps ST1601 to ST1629 shown are Fig.16 same.

[0192] exist Fig.19In step ST1730 shown, gNB#1 requests AMF#1 to change the UE's identity. For this request, for example, signaling in the N2 interface can be used. New signaling, such as signaling of the N2UE configuration update request, can be set and used. In step ST1732, AMF#1 changes the UE's identity. The identity can be, for example, 5G-S-TMSI.

[0193] exist Fig.19 In step ST1734 shown, AMF#1 indicates to the UE that the UE's identity is updated. For this indication, NAS signaling can be used, such as the configuration update indication (CONFIGURATIONUPDATE COMMAND) disclosed in non-patent document 27 (TS24.501). The indication may include, for example, the UE's updated 5G-S-TMSI. In step ST1736, the UE may use the indication to update the UE-ID of the UE.

[0194] exist Fig.19 In step ST1738 shown, the UE notifies the AMF of the completion of the identification update of the UE. For this notification, NAS signaling can be used, such as the configuration update completion (CONFIGURATION UPDATE COMPLETE) disclosed in non-patent document 27 (TS24.501).

[0195] exist Fig.19 In step ST1740 shown, the AMF notifies the base station of the changed identifier. For this notification, signaling on the N2 interface can be used. The notification can include the changed identifier. The identifier can be 5G-S-TMSI, UE-ID, or 5G-GUTI. In step ST1631, gNB#1 can use the changed identifier notified in the above step ST1740 to change the parameters related to the paging timing.

[0196] Fig.19 Steps ST1633, ST1635 and Fig.17 same.

[0197] Notification of the changed identity from the AMF to the base station can be performed before notification of the completion of the identity update of the UE from the UE to the AMF. Thus, for example, the flexibility of the paging timing change in the UE can be improved, and the base station can quickly determine the parameters related to the paging timing.

[0198] Fig. 20 and Fig.21 It is a sequence diagram of the third example showing the action in which a UE equipped with multiple SIMs detects a paging conflict and notifies the base station, and the base station requests the AMF for the UE's identification. Fig. 20 and Fig.21 Connect at the boundary line BL2021. Fig. 20 and Fig.21 In the example, the UE is connected to two NWs (NW#1 and NW#2), and is connected to gNB#1 to which NW#1 belongs and gNB#2 to which NW#2 belongs. Fig. 20 and Fig.21 In , AMF#1 and AMF#2 exist under the subordinate of NW#1 and NW#2 respectively. Fig. 20 and Fig.21 In the example shown, the UE is in RRC_IDLE state for both gNB#1 and gNB#2. Fig. 20 and Fig.21 This shows an example where the UE notifies gNB#1 of a paging conflict and gNB#1 requests AMF#1 to change the UE's identity. Fig. 20 and Fig.21 In, with Figure 16 to Figure 19 The same processing is assigned the same step numbers, and common descriptions are omitted.

[0199] Fig. 20 Steps ST1601 to ST1629 shown are Fig.16 same.

[0200] Fig.21 Steps ST1730 to ST1736 shown are Fig.19 same.

[0201] exist Fig.21 In step ST1840 shown in FIG. 1840, the AMF notifies the base station of the changed identifier. The notification can be Fig.19 The same as step ST1740 in.

[0202] Fig.21 Steps ST1631 to ST1635 shown are Fig.17 same.

[0203] Fig.21 Step ST1738 shown is the same as Fig.19 same.

[0204] exist Fig. 20 and Fig.21 , the case where the UE notifies the AMF of the completion of the identity update of the UE after the paging timing of the UE is changed is shown. As another example, the UE can notify the completion of the identity update of the UE before the paging timing is changed. For example, the UE can perform step ST1738 after the UE-ID is changed as shown in step ST1736. Thus, for example, the waiting time of the notification in the AMF can be shortened, and as a result, the efficiency of the operation in the AMF can be improved.

[0205] As another example of the notification from the UE to the NW, the UE may make the notification to the AMF. For example, the UE may make the notification to the AMF to which the base station with earlier PRACH transmission timing is connected among the base stations of the multiple NWs. Thus, for example, the UE can quickly connect to any one of the multiple NWs, as a result, paging conflicts can be quickly avoided.

[0206] The UE may use NAS signaling for the notification. The UE may include the NAS signaling in the RRC signaling, such as RRC Setup Complete, for notification. The gNB may extract the NAS signaling from the RRC signaling. The gNB may transmit the NAS signaling to the AMF. For this transmission, the signaling in the N2 interface may be used, such as the initial UE transfer (INITIAL UE TRANSFER) disclosed in non-patent document 26 (TS38.413). New signaling may be set for the transmission. Thus, for example, the UE is able to notify information related to paging conflicts in the initial NAS signaling after RRC establishment. As a result, the AMF can quickly obtain information related to paging conflicts.

[0207] As another example, new NAS signaling may be set. For example, signaling of a UE configuration update request from the UE to the AMF may be set. The UE may use the newly set NAS signaling to notify the AMF.

[0208] The UE may make the notification to the AMF of one NW. Thus, for example, in the communication system, paging conflicts can be avoided with less signaling. As another example, the UE may make the notification to the AMFs of multiple NWs. Thus, for example, in the communication system, the flexibility of paging timing changes can be improved.

[0209] The UE may notify the AMF of information for avoiding paging conflicts. The UE may include the information in the notification. The information may include the information of (1) to (10) above. The information may further include information related to this NW. The information related to this NW may also be the information after other NWs are replaced with this NW for the information of (1) to (10) above. Thus, for example, the AMF is able to obtain the parameters required for deriving the paging timing of the UE without any deficiency. As a result, paging conflicts in the UE can be reliably avoided. The AMF may use the information related to this NW to change the UE's identity. Thus, for example, paging conflicts in the changed UE's identity can be prevented.

[0210] The AMF can use this signaling to change the UE's identity. The AMF can notify the UE of the changed identity. For this notification, NAS signaling can be used, such as the configuration update indication (CONFIGURATION UPDATE COMMAND) disclosed in non-patent document 27 (TS24.501). The identity can be, for example, the 5G-S-TMSI (5GS-Temporary Mobile Subscription Identifier: 5G S-Temporary Mobile Subscription Identifier) ​​disclosed in non-patent document 22 (TS23.501). The UE can use this notification to update the UE-ID of this UE.

[0211] The UE may notify the AMF of the completion of the identity update of the UE. For this notification, NAS signaling may be used, such as the CONFIGURATION UPDATE COMPLETE disclosed in non-patent document 27 (TS24.501).

[0212] The AMF may notify the base station of the changed identifier. For the notification, signaling on the N2 interface may be used. The base station may use the notification to update the UE-ID. The base station may use the notification to change the paging timing. The base station may use the changed identifier of the UE to change the parameters used to determine the paging timing, or may not change it. Thus, for example, the flexibility of the paging timing change in the UE may be improved. Notification of the changed parameter from the base station to the UE may be the same as above.

[0213] The UE may notify the AMF of the other NW of the changed parameter notified by the AMF. The UE may include information related to the UE's identity in the notification to the AMF of the other NW. The identity may also be an identity allocated in the NW of the AMF that changed the parameter. The AMF of the other NW may use the parameter to change the paging timing in the other NW, or may not change it. Thus, for example, the paging timing in the other NW may be changed by avoiding the notified parameter. As a result, paging conflicts after the paging timing is changed may be prevented.

[0214] Fig. 22 and Fig.23 is a sequence diagram showing an example of the action of a UE equipped with multiple SIMs detecting a paging conflict and notifying the AMF. Fig. 22 and Fig.23 Connect at the boundary line BL2223. Fig. 22 and Fig.23 In the example, the UE is connected to two NWs (NW#1 and NW#2), and is connected to gNB#1 to which NW#1 belongs and gNB#2 to which NW#2 belongs. Fig. 22 and Fig.23In , AMF#1 and AMF#2 exist under the subordinate of NW#1 and NW#2 respectively. Fig. 22 and Fig.23 In the example shown, the UE is in RRC_IDLE state for both gNB#1 and gNB#2. Fig. 22 and Fig.23 An example is shown in which the UE notifies AMF#1 of a paging conflict via gNB#1. Fig. 22 and Fig.23 In, with Figure 16 to Figure 19 The same processing is assigned the same step numbers, and common descriptions are omitted.

[0215] Fig. 22 Steps ST1601 to ST1627 shown are Fig.16 same.

[0216] exist Fig. 22 In step ST1929 shown, the UE notifies gNB#1 of the completion of the RRC establishment. For this notification, RRC signaling, such as RRC Setup Complete (RRCSetupComplete) of non-patent document 24 (TS 38.331), can be used. The UE can include NAS signaling in the notification of step ST1629. The UE can include information related to paging conflicts in the NAS signaling. The information may include, for example, information related to the presence or absence of paging conflicts, and may also include the above-mentioned information (1) to (10) disclosed as examples of information for avoiding paging conflicts.

[0217] exist Fig.23 In step ST1931 shown, gNB#1 transmits the NAS signaling received from the UE to AMF#1. For this transmission, the signaling in the N2 interface, such as the initial UE transmission (INITIAL UE TRANSFER) disclosed in non-patent document 26 (TS 38.413), can be used. New signaling can be set for this transmission. AMF#1 recognizes the occurrence of a paging conflict by receiving the signaling of step ST1931.

[0218] Fig.23 Steps ST1732 to ST1740 shown are Fig.19 same.

[0219] Fig.23 The example in Figure 2 shows that gNB#1 does not change the parameters related to paging timing, but gNB#1 can also change the parameters. In this case, you can perform Fig.19 Steps ST1631 to ST1635 are shown. Thus, for example, in the communication system, the flexibility of changing the paging timing can be improved.

[0220] Other base stations may also obtain information related to paging conflicts. The other base stations may be, for example, a handover target base station of the UE (hereinafter sometimes referred to as a target base station). The handover source base station (hereinafter sometimes referred to as a source base station) may notify the target base station of information related to paging conflicts. The information may also be, for example, the information (1) to (10) above. Thus, for example, even after the UE performs handover, paging conflicts may be prevented.

[0221] The source base station can use signaling in the base station-to-base station interface (e.g., Xn interface), such as the signaling of the handover request (HANDOVER REQUEST) disclosed in non-patent document 28 (TS38.423) to make the notification. Thus, for example, the source base station can quickly notify the target base station of the information.

[0222] As another example, the UE may notify the target base station of the information. The UE may use the above-mentioned RRC signaling, such as RRC reconfiguration completion signaling, to make the notification. Thus, for example, the amount of signaling in the interface between base stations can be reduced.

[0223] The UE may notify the information related to the paging conflict to the base station with the earliest PRACH transmission timing among the base stations of the NW to which the UE is connected. Thus, for example, the UE can quickly notify the NW of the paging conflict.

[0224] As another example, the UE may set a primary NW or a secondary NW. The UE may make the notification to the base station and / or AMF of the primary NW or to the base station and / or AMF of the secondary NW. Thus, in the design of the communication system, the complexity of the processing for notifying information related to the paging conflict may be avoided.

[0225] A person can set the primary NW and / or the secondary NW for the UE. For example, the primary NW and the secondary NW can be set according to the person's preferences. Thus, paging conflict avoidance can be performed on the NW that the person likes. The settings of the primary NW and / or the secondary NW can be pre-stored in the UE. The UE can use the settings of the primary NW and / or the secondary NW at any time.

[0226] The UE can process the paging from multiple NWs in the order of arrival, thereby, for example, avoiding the complexity of the UE design.

[0227] As another example, the UE may process a later-arriving paging before an earlier-arriving paging. The above-mentioned action may be performed, for example, when a later-arriving paging with a high priority is received during the UE processing of the earlier-arriving paging. The base station may include information indicating the priority in the paging to notify the UE. The UE may use the information to decide whether to process the later-arriving paging. Thus, for example, a high-priority communication can be started quickly, and as a result, the QoS in the communication system can be ensured.

[0228] Other solutions are disclosed. The UE can receive paging from multiple NWs in a time-division manner. It can also send paging from multiple NWs in a time-division manner. The UE can use the paging timing after time-division multiplexing to receive paging from each NW. As a result, for example, power consumption in the UE can be reduced.

[0229] The UE can determine the time division multiplexing method of paging. The UE can notify the base station to receive paging in a time division multiplexing manner. The UE can make this notification to the base station of one NW, or to the base stations of multiple NWs, or to the base stations of all NWs of the connection target. The notification method from the UE to the base station can be the same as the notification method from the UE to the base station of information related to paging conflicts in the above-mentioned solution. The base station can use this notification to include information about the paging of the UE only in the paging timing received by the UE. Thereby, for example, power consumption in the base station can be reduced, and the number of UEs that can be accommodated in paging can be increased.

[0230] The notification from the UE to the base station may include information related to the paging timing after time division multiplexing. The information may include, for example, the information of (2) and / or (5) disclosed as information related to paging conflicts. As the information of (5), for example, information related to the paging cycle can be used. As the information related to the paging cycle, for example, the DRX (Discontinuous Reception) cycle (T) of the UE disclosed in non-patent document 25 (TS 38.304) can be used, or the total count (N) of paging frames in the cycle can be used.

[0231] As another example, the information may include information related to paging timing that is not allocated through time division multiplexing. The paging timing may be a PF (Paging Frame) that is not allocated through time division multiplexing, or a PO (Paging Occasion), or a PDCCH monitoring occasion for paging reception, or a combination of multiple of the above.

[0232] As another example, the UE may determine the time division multiplexing method of paging. The UE may not notify the base station to receive paging in a time division multiplexing manner. The UE may receive paging from each NW using the paging time division multiplexing method determined by the UE. Thus, for example, the complexity of the design of the communication system can be avoided.

[0233] As another example, the base station can determine the method of time division multiplexing of paging. The base station can be, for example, a base station of a secondary NW. The UE can request the time division multiplexing of paging from the base station. The decision of the base station can be made based on the request from the UE or without the request from the UE. The base station can notify the base stations of other NWs of the information of time division multiplexing of paging. The notification can be made via the UE. The base station can use RRC signaling for the notification, or it can use MAC signaling for the notification, or it can use L1 / L2 signaling for the notification. The notification of the UE to the base stations of other NWs can be made using RRC signaling, or it can be made using MAC signaling, or it can be made using L1 / L2 signaling. Thus, for example, the UE does not need to determine the method of time division multiplexing of paging, and as a result, the complexity of the design can be avoided.

[0234] The base station that determines the time division multiplexing method of paging can be a base station of one NW or a base station of multiple NWs. The UE can send the request to a base station of one NW or a base station of multiple NWs. By having the base stations of multiple NWs determine the method, the action of determining the time division multiplexing method of paging in the communication system can be quickly started, for example.

[0235] Fig.24 FIG. 1 is a diagram showing a first example of time division multiplexing of paging. Fig.24 In , the UE is connected to two NWs (NW#1, NW#2). Fig.24 In the figure, the four corners of the solid and dotted lines represent the paging timing before time division multiplexing in each NW. Fig.24 As a result of time division multiplexing, the UE may not receive paging from the NW at the four corners shown by the dotted lines. Fig.24 In the example shown, paging from NW#1 and paging from NW#2 are sent at the same cycle. Fig.24 In the example shown, the UE may alternately receive paging from NW#1 and NW#2.

[0236] Fig.25 A second example of time division multiplexing of paging is shown. Fig.25 In , the UE is connected to two NWs (NW#1, NW#2). Fig.25 In the figure, the four corners of the solid and dotted lines represent the paging timing before time division multiplexing in each NW. Fig.25 As a result of time division multiplexing, the UE may not receive paging from the NW at the four corners shown by the dotted lines. Fig.25 In the example shown, paging from NW#1 is sent at a greater period than paging from NW#2. Fig.25In the example shown, when the paging from NW#1 and NW#2 is repeated, the UE may receive the paging from NW#1.

[0237] Other solutions are disclosed. A base station can detect paging conflicts. The base station can be a base station of one NW or a base station of multiple NWs to which the UE is connected. The UE can notify the base station of the identity of the UE in other NWs. The notification can include information related to the cell to which the UE is connected in the other NW, such as PCI. The base station can obtain information related to paging in the other NW. The acquisition of the information in the base station can be performed by obtaining notification information from the base station of the other NW or by notification from the UE to the base station. Thus, for example, at the UE, the amount of processing related to paging conflicts can be reduced.

[0238] The method disclosed in this embodiment 1 can be applied to paging conflicts between NR base stations and LTE base stations. The LTE base station and / or the NW to which the LTE base station is connected can only change the identifier of the UE. Thus, for example, the complexity of the design in the communication system can be avoided. As another example, the LTE base station and / or the NW to which the LTE base station is connected can include other parameters related to paging and can be changed. Thus, for example, the flexibility of paging timing changes can be improved. The notification from the UE to the NR base station and / or AMF, and the notification from the UE to the LTE base station and / or MME can be the same as the above solution. The notification from the UE to the AMF to which the NR base station is connected, and the notification from the UE to the MME to which the LTE base station is connected can also be the same as the above solution. Thus, for example, the UE can avoid paging conflicts between the NR base station and the LTE base station.

[0239] The UE can notify the NR base station of the paging conflict. Thus, for example, in the communication system, the paging timing of the UE can be flexibly changed.

[0240] As another example, the UE may notify the LTE base station and / or MME of the paging conflict. Thus, for example, the amount of signaling between the UE and the NR base station can be reduced, and as a result, the communication speed in the communication system can be ensured.

[0241] The method disclosed in this embodiment 1 can be applied to paging conflicts between LTE base stations. The notification from the UE to the LTE base station and / or the MME can be the same as the above solution. Thus, for example, paging conflicts between LTE base stations can be avoided. The LTE base station and / or the NW to which the LTE base station is connected can only change the identifier of the UE. Thus, for example, the complexity of the design in the communication system can be avoided. As another example, the LTE base station and / or the NW to which the LTE base station is connected can include other parameters related to paging and can be changed. Thus, for example, the flexibility of paging timing changes can be improved.

[0242] The UE may have multiple RRCs. For example, when the UE is equipped with multiple SIM cards, the UE may be allowed to have multiple RRCs. For example, the UE may have an RRC for each of the base stations of multiple NWs. Thus, for example, control between the UE and each base station becomes easy.

[0243] As another example, the UE may have an RRC for each transceiver. The same approach may be used when the number of transmitters and receivers of the UE is different. For example, the UE may have an RRC for each transmitter of the UE, or may have an RRC for each receiver of the UE. The UE may have a larger number of RRCs of the number of transmitters and the number of receivers of the UE, or may have a smaller number of RRCs. Thus, for example, each transceiver of the UE may be easily controlled.

[0244] As another example, the UE may have only one RRC. For example, even if the UE is a UE equipped with multiple SIMs, it may have only one RRC. The same approach may be adopted in the case where the UE has multiple transceivers. The same approach may be adopted in the case where the number of transmitters and receivers possessed by the UE is different. For example, when the UE has only one transmitter, the UE may have only one RRC. For example, when the UE has only one receiver, the UE may have only one RRC. As a result, for example, control between the UE and base stations of multiple NWs, such as adjustment of frequency, time and / or power resources between base stations of multiple NWs, becomes easy.

[0245] The UE may have multiple RRC states. For example, when the UE is a UE equipped with multiple SIMs, the UE may be allowed to have multiple RRC states. For example, an RRC may be provided for each of the base stations of multiple NWs. The UE may have one RRC state for one RRC, or may have multiple RRC states for one RRC. Thus, for example, the communication system may easily control the connection state with each base station.

[0246] As another example of a UE having multiple RRC states, an RRC state may be provided for each transceiver. The same approach may be used when the number of transmitters and receivers provided by the UE is different. For example, the UE may have an RRC state for each transmitter provided by the UE, or may have an RRC state for each receiver provided by the UE. The UE may have a larger number of RRC states between the number of transmitters and the number of receivers provided by the UE, or may have a smaller number of RRC states. Thus, for example, the operating conditions of each transceiver of the UE may be easily controlled.

[0247] The multiple RRC states that the UE has may be independent of each other. For example, in the case where the UE has multiple transceivers, the multiple RRC states may be independent of each other. As another example, in the case where the UE has a single transceiver, the multiple RRC states may be independent of each other. Thus, for example, the flexibility in the communication system may be improved.

[0248] As another example, the multiple RRC states possessed by the UE may have mutual dependencies. For example, when the RRC state between the base station of one NW is changed to RRC_CONNECTED, the RRC state between the base stations of other NWs may be changed to RRC_CONNECTED. As another example, when the RRC state between the base station of one NW is changed to RRC_IDLE or RRC_INACTIVE, the RRC state between the base stations of other NWs may be changed to RRC_IDLE or RRC_INACTIVE. For example, in the case where the UE has one transceiver, there may be mutual dependencies between multiple RRC states. As another example, in the case where the UE has multiple transceivers, there may be mutual dependencies between multiple RRC states. As a result, for example, the control of the RRC state in the communication system becomes easy.

[0249] The UE may have only one RRC state. Thus, for example, the operating condition of the UE may be easily controlled.

[0250] The method disclosed in this embodiment 1 can also be applied to the reception of SS blocks and / or system information. For example, the UE can receive SS blocks from base stations of multiple NWs in a time-division manner. As another example, the UE can request a base station of one NW to avoid system information transmission timing conflicts. The base station can use the request to change the system information transmission timing. Thus, for example, for SS blocks and / or system information, transmission timing conflicts can also be avoided.

[0251] According to the first embodiment, duplication of paging between NWs can be avoided.

[0252] Modification 1 of Embodiment 1 In a communication system in which a plurality of NWs share the same base station, the same method as in the first embodiment can be applied.

[0253] Fig.26 This is an architectural diagram showing an example of connection between UEs equipped with multiple SIMs and multiple NWs in a communication system where multiple NWs share the same base station. Fig.26 In the example, PLMN#1 and PLMN#2 share the same base station 2201. Fig.26 In the example, a UE equipped with multiple SIM cards is connected in parallel to PLMN#1 and PLMN#2.

[0254] exist Fig.26 In the example shown, UE1400 is connected to gNB2201. gNB2201 is connected to AMF1402 and UPF1403 in PLMN#1. SMF1404 in PLMN#1 is connected to AMF1402 and UPF1403. gNB2201 is connected to AMF1412 and UPF1413 in PLMN#2. SMF1414 in PLMN#2 is connected to AMF1412 and UPF1413.

[0255] Although in Fig.26 The example shown shows a case where UE 1400 is connected to two PLMNs, but UE 1400 may also be connected to more than three PLMNs. In addition, one or more of the two NWs to which UE 1400 is connected may also be NPNs. The same is true when UE 1400 is connected to more than three NWs.

[0256] The UE may notify the base station of a paging timing conflict between multiple NWs. The notification may also be the same as the notification disclosed in Implementation 1. As another example, the UE may notify the AMF of a paging timing conflict between multiple NWs. The AMF may be the AMF of one NW or the AMF of multiple NWs. The notification from the UE to the AMF may be the same as the notification disclosed in Implementation 1. Thus, for example, even in a communication system where multiple NWs share a base station, paging conflicts can be avoided.

[0257] Other solutions are disclosed. The base station can detect the paging timing conflict. The base station can change the paging parameters at each NW. The base station can notify the UE of the changed parameters or notify them separately.

[0258] The UE can notify the base station of the identifier of the UE assigned by each NW. Thus, for example, the base station can recognize that the identifier of the UE at each NW is the identifier of the same UE. As a result, the base station can perform a parameter change for avoiding paging conflicts. The identifier can be UE_ID or 5G-S-TMSI. Thus, for example, the amount of signaling of the notification from the UE to the base station can be reduced. As another example, the identifier can be 5G-TMSI. Thus, for example, the UE can simultaneously notify the base station of the identifier of the NW, as a result, the identification in the base station can be performed quickly. As another example, the identifier can be 5G-GUTI.

[0259] As another example, the base station may use NAS signaling between the UE and the AMF of each NW to obtain the identity of the UE allocated by each NW. For example, the base station may use the NAS signaling involved in the UE's login to each NW to obtain the identity of the UE in the NW. The base station may decode the NAS signaling. Thus, for example, the signaling between the UE and the base station can be reduced.

[0260] The base station may request the AMF to change the UE's identity. The request may be the same as the request for UE identity change from the base station to the AMF disclosed in Implementation 1. The AMF may use the request to change the UE's identity. The AMF may notify the UE of the change in UE identity. For the notification, the NAS signaling disclosed in Implementation 1 may be used, such as the CONFIGURATION UPDATE COMMAND disclosed in Non-Patent Document 27 (TS24.501).

[0261] The UE may notify the AMF of the completion of the identity update of the UE. For this notification, similar to implementation mode 1, NAS signaling may be used, such as the configuration update completion (CONFIGURATION UPDATE COMPLETE) disclosed in non-patent document 27 (TS24.501).

[0262] The AMF may notify the base station of the changed identity. For this notification, as in implementation mode 1, signaling on the N2 interface may be used. The base station may use this notification to change the paging timing of the UE, or may not change it.

[0263] Other solutions are disclosed. The paging may include information related to the NW. The information related to the NW may be, for example, an identifier indicating a PLMN and / or an NPN. The information may be set to indicate which NW the paging information is related to. The information related to the NW may be associated with the paging information to form the paging information. The UE may identify which NW the received paging information corresponds to.

[0264] The base station can send paging to any NW. For example, the base station can send paging to the main NW. The paging includes information related to the above NW. Thus, the UE can obtain paging information of multiple NWs by receiving paging at the paging timing of one NW.

[0265] The base station may notify the information used to determine the one NW. The information used to determine the one NW may be, for example, the identifier of the NW. The base station may separately notify the UE of the information used to determine the one NW. For example, the notification may use RRC signaling. In addition, the base station may notify the information related to the paging timing of the one NW. Alternatively, the base station may separately notify the UE of the information related to the paging timing of the one NW. For example, the notification may use RRC signaling. Thus, the UE may determine the one NW, derive the paging timing of the NW, and may receive paging at the paging timing of the NW.

[0266] Therefore, the UE only needs to receive paging at the paging timing from one NW, which can avoid the complexity of the UE's paging processing.

[0267] According to the present modification 1, paging conflicts can be avoided even in a communication system in which a base station is shared by a plurality of NWs.

[0268] Modification 2 of Implementation Example 1 In Embodiment 1, a method for avoiding paging conflicts between multiple NWs is disclosed. In Modification 2, a method for avoiding random access contention is disclosed.

[0269] The UE detects a collision of random accesses between base stations of multiple NWs. As in Embodiment 1, the UE may detect a collision using information related to frame timing between base stations of multiple NWs, or may detect a collision using system information received from the multiple base stations, such as system information related to random access. The above two may be combined.

[0270] The UE notifies a base station of a NW of information related to the random access conflict. The base station may be, for example, the base station of the main NW disclosed in Implementation 1. The base station may use the notification from the UE to change the timing of random access to the UE. The timing of random access may be, for example, the timing of PRACH transmission from the UE or the timing of RAR received by the UE. The base station may notify the UE of the changed timing.

[0271] The base station may change the preamble of random access. The base station may notify the UE of information related to the changed preamble. The UE may use the changed preamble to send PRACH to the base station. Thus, for example, it is possible to prevent the base station of other NWs from mistaking the PRACH of the base station from the UE as the PRACH for the base station. In addition, it is possible to prevent the base station from mistaking the PRACH for the base station of other NWs as the PRACH for the base station.

[0272] The following (1) to (8) are disclosed as information related to random access processing with base stations of other NWs, which is notified by the UE to the base station.

[0273] (1) Information related to the identification of base stations of other NWs.

[0274] (2) Information related to the PRACH transmission timing to base stations of other NWs.

[0275] (3) Information related to parameter sets of base stations of other NWs.

[0276] (4) Information related to frame timing of base stations of other NWs.

[0277] (5) Information related to the RAR reception timing from base stations of other NWs.

[0278] (6) Information related to beams received from base stations of other NWs.

[0279] (7) Information related to the preamble code of the PRACH to the base station of other NW.

[0280] (8) A combination of the above (1) to (7).

[0281] The information in (1) above may be, for example, a base station identifier of a base station that does not transmit or receive data (hereinafter sometimes referred to as an inactive base station), or a cell identifier. Thus, for example, a base station that transmits or receives data (hereinafter sometimes referred to as an active base station) can grasp the inactive base station from which the UE is to receive synchronization signals, system information, and / or paging. As a result, the complexity associated with scheduling of the active base station can be avoided.

[0282] The information in (2) above may be information related to the start timing of the PRACH sent by the UE. The information may be SFN, subframe number, time slot number or symbol number, or a combination thereof. The information may include information related to the length of the PRACH sent by the UE, and may also include information related to the end timing of the PRACH. Therefore, for example, the UE can notify information related to the PRACH sent by the UE with less signaling.

[0283] As another example, the information in (2) above may include information related to the time of the PRACH sent by the UE. The information related to the time may include, for example, the time at the start point of the PRACH, the time related to the end point of the PRACH, the information related to the length of the PRACH, or multiple information of the above. Thus, for example, the amount of random access conflict avoidance processing performed by the base station can be reduced.

[0284] The information in (3) above may be, for example, the subcarrier spacing, slot length, or symbol length used by the UE in the random access process with the base station of another NW, or the parameter μ disclosed in Section 4.2 of Non-Patent Document 13 (TS38.211). Thus, for example, the reliability of the avoidance process performed by the base station can be improved.

[0285] The information of (4) above may be the same as the information of (4) above for avoiding paging conflicts disclosed in Implementation 1. The information may also be, for example, information related to the difference in frame timing between the base station and the base station of another NW. Thus, for example, the amount of processing in the avoidance processing performed by the base station can be reduced. As another example, it may be a specified time point in the base station of another NW, for example, at the boundary of a specified SFN. Thus, for example, the amount of processing required for the notification of the UE can be reduced.

[0286] The information in (5) above may include, for example, information related to the starting point of the RAR reception timing, information related to the end point, and information related to the length of the RAR reception timing. This information may be matched, for example, in the same form as in (2) above. As another example, the information in (5) above may also be the ra-ResponseWindow disclosed in non-patent document 24. Thus, for example, in the UE, conflicts between the timing of transmission and reception with the base station and the RAR from base stations of other NWs can be prevented.

[0287] The information in (6) above may also be information related to the beam used by the UE when receiving an SS block from a base station of another NW. The information may also be, for example, an identifier of the SS block within an SS burst. The base station may not use the information to transmit and receive with the UE only at the random access timing corresponding to the SS block received by the UE. Thus, for example, the communication rate between the UE and the base station may be increased.

[0288] The information in (7) above may include, for example, information related to the preamble code of the PRACH sent by the UE to the base station of other NWs. The base station may use the information to allocate a preamble code different from the preamble code to the UE for PRACH transmission to the base station. Thus, for example, the base station may be prevented from mistaking the PRACH sent from the UE to the base station of other NWs as the PRACH to the base station.

[0289] Other solutions are disclosed. The UE may send PRACH to one base station. The UE may not send PRACH to other base stations. The UE may send PRACH to the base station with the earliest header of the PRACH transmission timing. Thus, for example, the UE is able to quickly establish a connection. As another example, the UE may send PRACH to a base station that performs high-priority communications. The UE may use the priority information included in the paging disclosed in Implementation 1 to determine the base station, and may also use the priority information of the uplink communication generated in the UE to determine the base station. Thus, for example, the UE is able to quickly start high-priority communications, as a result of which the QoS of the communication can be ensured.

[0290] Other solutions are disclosed. The UE may send PRACH to multiple base stations. This action of the UE may be performed, for example, when the UE has multiple transceivers. Thus, for example, the UE can quickly establish connections with multiple base stations.

[0291] The UE may allocate power to each base station using the path loss between the UE and the base station, may allocate power using the priority of communication with each base station, or may allocate power using both methods. This may improve the efficiency of the communication system, for example.

[0292] According to the second modification, it is possible to avoid collision of random access timings among a plurality of NWs.

[0293] Implementation Method 2 A UE equipped with multiple SIMs can perform a reception action of synchronization signals, system information and / or paging. The UE can perform the reception action on a base station that does not transmit or receive data (hereinafter sometimes referred to as an inactive base station). The UE can perform the reception action by switching the transceiver of the UE during the connection process with a base station that transmits or receives data (hereinafter sometimes referred to as an activated base station). An inactive base station may be, for example, a base station relative to an RRC in an RRC_IDLE state or an RRC_INACTIVE state. An activated base station may be, for example, a base station relative to an RRC in an RRC_CONNECTED state. The UE may be a receiver having only one transceiver.

[0294] The UE may notify the activated base station of information related to the timing of receiving synchronization signals, system information and / or paging from the inactivated base station. The UE may request the activated base station to avoid paging conflicts from the inactivated base station. The request may include the above information. The UE may switch the receiving target to the inactivated base station at this timing.

[0295] The reception timing may include the time required for the UE to switch the transceiver. Thus, for example, the reliability of receiving synchronization signals, system information and / or paging from the inactive base station may be improved.

[0296] As the information related to the reception timing notified by the UE to the activated base station, that is, information related to the timing at which the UE receives a synchronization signal, system information and / or paging from the inactive base station, the following (1) to (9) are disclosed.

[0297] (1) Information related to the identification of inactive base stations.

[0298] (2) Information related to the synchronization signal transmission timing of the inactive base station.

[0299] (3) Information related to parameter sets of inactive base stations.

[0300] (4) Information related to the frame timing of the inactive base stations.

[0301] (5) Information used for deriving the synchronization signal transmission timing of the inactive base station.

[0302] (6) Information related to beams received from inactive base stations.

[0303] (7) Information related to the timing of sending system information of inactive base stations.

[0304] (8) Information related to the timing of receiving paging from an inactive base station.

[0305] (9) A combination of the above (1) to (8).

[0306] The information in (1) above may be, for example, a base station identifier of a non-activated base station or a cell identifier. Thus, for example, the activated base station can grasp the non-activated base station from which the UE is to receive synchronization signals, system information and / or paging. As a result, the complexity associated with scheduling of the activated base station can be avoided.

[0307] The information in (2) above may be, for example, the frame timing of the inactive base station transmitting the SS burst, for example, the SFN. The SFN may be, for example, the SFN that becomes the head of the SS burst, or the SFN that becomes the end of the SS burst. Thus, for example, the amount of scheduling processing in the active base station may be reduced. In addition, even when there is a timing offset between the active base station and the inactive base station, a synchronization signal, system information, and / or paging may be received from the inactive base station.

[0308] As another example, the information in (2) above may include information related to the time when the inactive base station sends the SS burst. The information related to the time may include, for example, the time at the start of the SS burst, the time related to the end of the SS burst, the information related to the duration of the SS burst, or multiple information thereof. Thus, for example, the amount of scheduling processing in the active base station may be reduced.

[0309] The information in (3) above may be, for example, a subcarrier spacing, a time slot length, or a symbol length used by the UE when receiving a synchronization signal, system information, and / or paging from an inactive base station, or may be a parameter μ disclosed in Section 4.2 of Non-Patent Document 13 (TS38.211). Thus, for example, in scheduling of an activated base station, the reliability of an action for avoiding a synchronization signal or the like from an inactive base station may be improved.

[0310] The information in (4) above may be the same as the information in (4) above for avoiding paging conflicts disclosed in Implementation 1. The information may also be, for example, information related to the difference in frame timing between the activated base station and the inactivated base station. Thus, for example, the amount of processing required for scheduling in the activated base station may be reduced. As another example, the information in (4) above may be a specified time point in the inactivated base station, for example, a time at the boundary of a specified SFN. Thus, for example, the amount of processing required for the notification of the UE may be reduced.

[0311] The information in (5) may include information on the period of the SS burst, or may include information indicating whether the SS burst is included in the first half or the second half of the frame. This can reduce the amount of scheduling processing in the active base station, for example.

[0312] The information in (6) above may also be information related to the beam used by the UE when receiving the SS block from the inactive base station. The information may also be, for example, the identifier of the SS block in the SS burst. The activated base station may transmit and receive with the UE only without using the information at the timing of the SS block received by the UE. Thus, for example, the communication rate between the UE and the activated base station may be increased.

[0313] As another example, the information in (6) above may also be information related to a candidate beam used when the UE receives an SS block from an inactive base station. The information related to the candidate beam may be, for example, an identifier of an SS block transmitted using a beam around an SS block received by the UE. Thus, for example, the communication rate between the UE and the active base station may be increased. At the same time, even when the beam of the inactive base station where the UE is located is changed, the UE may receive an SS block from the inactive base station.

[0314] The information in (6) above may be information related to a beam or its candidates used when the UE receives system information from an inactive base station, or may be information related to a beam or its candidates used for paging reception.

[0315] The information in (7) above may be, for example, information related to the scheduling of system information transmitted by the inactive base station. The information related to scheduling may be, for example, pdcch-ConfigSIB1 disclosed in Non-Patent Document 24 (TS 38.331). Thus, for example, the amount of scheduling processing in the active base station can be reduced.

[0316] The information in (8) may be information related to the paging timing of the inactive base station. This information may be the same as the information in (2) for avoiding paging conflicts disclosed in Embodiment 1. Thus, for example, the amount of scheduling processing in the active base station can be reduced.

[0317] As another example, the information in (8) may be information used in deriving the paging timing of the inactive base station. This information may be the same as the information in (5) for avoiding paging conflicts disclosed in Embodiment 1. Thus, for example, the amount of signaling from the UE to the active base station can be reduced, and the amount of scheduling processing in the active base station can be reduced.

[0318] The UE may use RRC signaling to send the notification to the activated base station. Thus, for example, the UE can notify the activated base station of more information.

[0319] As another example, the UE may use MAC signaling to send the notification to the activated base station. Thus, for example, the UE can quickly perform the notification while ensuring reliability through HARQ retransmission control.

[0320] As another example, the UE may use L1 / L2 signaling to send the notification to the activated base station. Thus, for example, the UE can further quickly perform the notification.

[0321] As another example, the UE may use NAS signaling to send the notification to the AMF connected to the activated base station. Thus, for example, it is not necessary to transmit the information included in the notification between base stations accompanying the handover of the UE. As a result, the amount of signaling between base stations can be reduced.

[0322] As another example, the above methods may be combined. For example, the UE may use RRC signaling to notify the activated base station of the above information (1) to (5), (7) and / or (8), and use L1 / L2 signaling to notify the activated base station of the above information (6). Thus, for example, more information can be quickly notified from the UE to the activated base station.

[0323] The activated base station can use the notification from the UE to change the scheduling of the UE. The change can, for example, be that the transmission and reception for the UE is not allocated when the UE receives the synchronization signal, system information and / or paging from the inactivated base station. The activated base station can notify the UE of information related to the changed scheduling. The information is, for example, information related to the timing of the UE to perform a PDCCH reception action, such as the control resource set (Control Resource SET; CORESET) allocated to the UE, and can also be information related to a configured grant. Thereby, for example, the reliability of the communication between the activated base station and the UE can be improved.

[0324] The activated base station can use the notification from the UE to change the scheduling of the UE. As another change example, for example, a period in which no transmission or reception is performed between the activated base station and the UE can be set. The activated base station can notify the UE of the period. The UE can transmit or receive with the inactivated base station during the period. In the UE, the transmission or reception of the activated base station and the transmission or reception of the inactivated base station can be time-multiplexed. By setting the period to a longer period, the UE can complete the communication with the activated base station and the communication with the inactivated base station without frequently alternating. The use efficiency of wireless resources can be improved.

[0325] The UE can use the information received from the activated base station to switch the transceiver of the UE to the inactive base station or to the activated base station. For example, the UE can switch the transceiver of the UE to the inactive base station at the timing of receiving a paging from the inactive base station. Thus, for example, the UE can receive a paging from the inactive base station.

[0326] Other solutions are disclosed. The UE may notify the inactive base station of information about the transmission and reception between the UE and the activated base station. In the above, the RRC state of the UE relative to the inactive base station may be transferred to RRC_CONNECTED. The inactive base station may use the notification to change the synchronization signal and / or paging timing. For example, the inactive base station may allocate the synchronization signal and / or paging timing avoiding the timing scheduled by the activated base station for the UE. The change in the inactive base station may be, for example, the same as the method disclosed in Implementation 1. Thus, for example, the communication rate between the activated base station and the UE may be ensured while receiving the synchronization signal, system information and / or paging of the inactive base station.

[0327] The following (1) to (10) are disclosed as information related to transmission and reception between the UE and the activated base station, which is notified by the UE to the inactivated base station.

[0328] (1) Information related to the identity of the activated base station.

[0329] (2) Information related to the timing of activating the base station's synchronization signal transmission.

[0330] (3) Information related to the parameter set of the activated base station.

[0331] (4) Information related to the frame timing of the activated base station.

[0332] (5) Information used for deriving the synchronization signal transmission timing of the activated base station.

[0333] (6) Information related to the beams received from the activated base stations.

[0334] (7) Information related to the timing of sending system information of the activated base station.

[0335] (8) Information related to the timing of receiving a paging message from an activated base station.

[0336] (9) Information related to scheduling in activated base stations.

[0337] (10) A combination of the above (1) to (9).

[0338] The information (1) to (8) above may be the same as the information (1) to (8) above disclosed as the information related to the reception timing notified by the UE to the activated base station, that is, the information related to the timing of the UE receiving the synchronization signal, system information and / or paging from the inactivated base station. For example, by using the information (8) above, the UE can receive system information changes and / or emergency information from the activated base station. At the same time, the inactivated base station can change the timing of the synchronization signal, system information and / or paging.

[0339] The information in (9) above is, for example, information related to the timing of the UE's PDCCH reception action to be performed by the activated base station, such as the control resource set (Control Resource SET; CORESET) allocated to the UE, or information related to a configured grant from the activated base station. Thus, for example, the inactivated base station can change the timing of the synchronization signal, system information and / or paging without affecting the communication between the activated base station and the UE.

[0340] The UE may use a measurement gap when receiving a synchronization signal from an inactive base station. For example, the UE may use a measurement gap that has been set to receive a synchronization signal from an inactive base station. In addition, for example, the activated base station may set a measurement gap for the UE to allow communication with the inactive base station. Existing measurement gaps may be used. Since no new processing is required, the complexity of these processes may be avoided. Alternatively, a new gap may be set, and an existing measurement gap setting method may be used as its setting method. By setting a new gap, the gap period may be optimally set to communicate with the inactive base station. Thus, for example, the UE may maintain the communication rate with the activated base station while establishing synchronization of the downlink signal with the inactive base station.

[0341] As another example, the UE may not use measurement gaps when receiving synchronization signals from an inactive base station. For example, when the active base station and the inactive base station use the same frequency band for the UE, measurement gaps may not be used. Thus, for example, efficiency in the communication system can be improved.

[0342] The method disclosed in this embodiment 2 can be used for receiving paging from an activated base station. For example, the UE can switch the transceiver of the UE from data transmission and reception with the activated base station to paging reception from other activated base stations at the paging reception timing. Thus, for example, the UE can receive system information changes and / or emergency information from other activated base stations.

[0343] Other solutions are disclosed. The UE may not notify the activated base station of information related to the reception timing of the synchronization signal, system information and / or paging from the inactive base station. The UE may switch the transceiver of the UE to the inactive base station at the reception timing. Thus, for example, the UE can avoid the complexity of processing the signal received from the inactive base station.

[0344] In the above, retransmission of the transmission and reception between the activated base station and the UE may be performed. The retransmission may be, for example, retransmission of the transmission and reception that occurred during the period when the UE switched the transceiver of the UE to the inactive base station. Thus, for example, the reliability of the transmission and reception between the activated base station and the UE may be improved.

[0345] The method disclosed in this embodiment 2 can be applied to a UE having multiple transceivers. The UE can, for example, use multiple transceivers to connect to one NW. The UE can be connected to multiple base stations in one NW. The UE can form a dual connection with the multiple base stations. The UE can switch the transceiver of the UE to the non-activated base station at the timing of sending a synchronization signal, system information and / or paging from the non-activated base station in other NWs.

[0346] When the UE forms the dual connection, the transceiver facing the secondary base station can be switched to the transceiver facing the inactive base station. Thus, for example, the communication between the UE and the primary base station can be maintained, and as a result, the robustness of the communication system can be maintained.

[0347] As another example, the transceiver facing the primary base station can be switched to facing the inactive base station. Thus, for example, when high-speed communication is performed between the UE and the secondary base station, the communication between the UE and the secondary base station can be maintained. As a result, the transmission speed in the communication system can be maintained.

[0348] When the transceiver facing the primary base station switches to the transceiver facing the inactive base station, the secondary base station may become the primary base station. Thus, for example, the handover in the UE may be performed with a small amount of signaling.

[0349] In this embodiment 2, the UE can receive a synchronization signal, system information and / or paging from an inactive base station. As a result, the UE can quickly resume communication with the base station.

[0350] Modification 1 of Implementation Example 2 In the second embodiment, the switching of the transceiver of the UE from being oriented to the active base station to being oriented to the inactive base station can also be applied to the random access process between the UE and the inactive base station.

[0351] The UE may notify the activated base station of information related to the random access process between the UE and the inactivated base station. The information may include information related to the timing of the random access process between the UE and the inactivated base station. At this timing, the activated base station may not allocate the transmission and reception timing between the UE and the base station.

[0352] As information related to a random access process between the UE and the inactive base station, which is notified by the UE to the active base station, the following (1) to (8) are disclosed.

[0353] (1) Information related to the identification of inactive base stations.

[0354] (2) Information related to the timing of PRACH transmission to the inactive base station.

[0355] (3) Information related to parameter sets of inactive base stations.

[0356] (4) Information related to the frame timing of the inactive base stations.

[0357] (5) Information related to the timing of receiving RAR from an inactive base station.

[0358] (6) Information related to beams received from inactive base stations.

[0359] (7) Information related to the preamble code of the PRACH to the inactive base station.

[0360] (8) A combination of the above (1) to (7).

[0361] The information (1) above may be the same as the information (1) disclosed in Implementation Example 2, which is related to the reception timing of the synchronization signal, system information and / or paging sent from the inactive base station (hereinafter sometimes referred to as the synchronization timing of the inactive base station).

[0362] The information in (2) above may be information related to the start timing of the PRACH sent by the UE. The information may be SFN, subframe number, time slot number or symbol number, or a combination thereof. The information may include information related to the length of the PRACH sent by the UE, and may also include information related to the end timing of the PRACH. Therefore, for example, the UE can notify information related to the PRACH sent by the UE with less signaling.

[0363] As another example, the information in (2) above may include information related to the time when the UE sends the PRACH. The information related to the time may include, for example, the time at the start point of the PRACH, the time related to the end point of the PRACH, the information related to the length of the PRACH, or multiple information of the above. Thus, for example, the amount of processing for scheduling in the activation base station can be reduced.

[0364] The information of (3) and (4) above may be the same as the timing information (3) and (4) of synchronization of the inactive base station.

[0365] The information in (5) above may include, for example, information related to the start point of the RAR reception timing, information related to the end point, and information related to the length of the RAR reception timing. This information may be matched, for example, in the same form as in (2) above. As another example, the information in (5) above may also be the ra-ResponseWindow disclosed in non-patent document 24. Thus, for example, in the UE, a conflict between the timing of transmission and reception with the activated base station and the RAR from the inactivated base station can be prevented.

[0366] The information of (6) above may be the same as the timing information (6) of synchronization of the inactive base station.

[0367] The information in (7) above may include, for example, information related to the preamble of the PRACH sent by the UE to the inactive base station. The activated base station may use this information to assign a preamble different from the preamble to the UE for PRACH transmission to the base station. Thus, for example, the activated base station may be prevented from mistaking the PRACH sent from the UE to the inactive base station as the PRACH to the base station.

[0368] Similar to implementation mode 2, the UE may use RRC signaling to make the notification, or may use MAC signaling to make the notification, or may use L1 / L2 signaling to make the notification. As another example, the UE may use NAS signaling to make the notification to the AMF to which the activated base station is connected.

[0369] The activated base station may use the notification to not perform uplink and / or downlink scheduling for the UE at the PRACH transmission timing from the UE to the inactivated base station and / or the RAR transmission timing from the inactivated base station to the UE. In addition, at this timing, no transmission or reception for the UE may be allocated.

[0370] Fig. 27 and Fig.28 This is a sequence diagram showing a first example of the operation of random access processing between a UE equipped with multiple SIMs and an inactive base station. Fig. 27 and Fig.28 Connect at the boundary line BL2728. Fig. 27 and Fig.28 In the example, the UE is connected to two NWs (NW#1 and NW#2), and is connected to gNB#1 to which NW#1 belongs and gNB#2 to which NW#2 belongs. Fig. 27 and Fig.28 In , AMF#1 and AMF#2 exist under the subordinate of NW#1 and NW#2 respectively. Fig. 27 and Fig.28 In the example shown, gNB#1 is an activated base station and gNB#2 is an inactive base station. Fig. 27 and Fig.28 In, with Fig.16 and Fig.17 The same processing is assigned the same step numbers, and common descriptions are omitted.

[0371] Fig. 27 Steps ST1601 to ST1603 shown are Fig.16 same.

[0372] exist Fig. 27 In step ST2304 shown, data is sent and received between UE and gNB#1.

[0373] exist Fig. 27 In step ST2306 shown, gNB#1 notifies the UE of system information. In step ST2307, gNB#2 notifies the UE of system information. The notification in step ST2307 includes parameters related to PRACH transmission for gNB#2, such as information related to PRACH transmission timing. The notification in step ST2307 may include information related to RAR transmission from gNB#2.

[0374] exist Fig. 27 In step ST2308 shown, the UE obtains the RACH timing at gNB#2.

[0375] exist Fig. 27 In step ST2310 shown, the UE notifies gNB#1 of information related to the RACH between gNB#2. In step ST2312, gNB#1 schedules the UE by avoiding the transmission timing of PRACH and RAR between the UE and gNB#2.

[0376] exist Fig. 27 In step ST2314 shown, data is sent and received between UE and gNB#1. The data transmission and reception in step ST2314 is performed while avoiding the transmission timing of PRACH and RAR between UE and gNB#2.

[0377] exist Fig.28 In the step ST2320 shown, it is assumed that uplink data is generated from UE to gNB#2.

[0378] exist Fig.28 In step ST2322 shown, the UE sends PRACH to gNB#2. gNB#1 does not schedule the UE at the timing of step ST2322.

[0379] exist Fig.28 In step ST2324 shown, gNB#2 sends RAR to UE. gNB#1 does not schedule UE at the timing of step ST2324.

[0380] exist Fig.28 In step ST2326 shown, the UE requests gNB#2 to establish RRC. This request can be made using RRC signaling, such as the RRC setup request (RRCSetupRequest) of non-patent document 24 (TS 38.331). In step ST2328, gNB#2 instructs the UE to establish RRC. For this indication, RRC signaling, such as the RRC setup (RRCSetup) of non-patent document 24 (TS38.331), can be used. Fig.28 In step ST2330 shown, the UE notifies gNB#2 of the completion of the RRC establishment. For this notification, RRC signaling, such as RRC Setup Complete (RRCSetupComplete) of non-patent document 24 (TS 38.331), can be used. Through step ST2330, the RRC connection between the UE and gNB#2 is established.

[0381] exist Fig.28 In step ST2332 shown, data is sent and received between UE and gNB#2. Fig.28 In step ST2334 shown, data is sent and received between UE and gNB#1.

[0382] As another example, the UE may make the notification to the activated base station after generating uplink data to the inactivated base station. Thus, for example, scheduling performed by the activated base station avoiding the transmission timing of PRACH and RAR may be performed after generating the uplink data. As a result, the communication efficiency between the UE and the activated base station may be improved.

[0383] Fig.29 and Fig.30 This is a sequence diagram showing a second example of the operation of random access processing between a UE equipped with multiple SIMs and an inactive base station. Fig.29 and Fig.30 Connect at the boundary line BL2930. Fig.29 and Fig.30 In the example, the UE is connected to two NWs (NW#1 and NW#2), and is connected to gNB#1 to which NW#1 belongs and gNB#2 to which NW#2 belongs. Fig.29 and Fig.30 In , AMF#1 and AMF#2 exist under the subordinate of NW#1 and NW#2 respectively. Fig.29 and Fig.30 In the example shown, gNB#1 is an activated base station and gNB#2 is an inactive base station. Fig.29 and Fig.30 In, with Figure 16-17 , Figure 27-28 The same processing is assigned the same step numbers, and common descriptions are omitted.

[0384] Fig.29 Steps ST1601 to ST1603 shown are Fig.16 same. Fig.29 Steps ST2304 to ST2308, ST2320 and Fig. 27 same.

[0385] exist Fig.29 In step ST2410 shown, the UE notifies gNB#1 of information related to RACH between gNB#2. The UE can perform step ST2410 after step ST2320. In step ST2412, gNB#1 avoids the transmission timing of PRACH and RAR between the UE and gNB#2 to perform scheduling for the UE.

[0386] exist Fig.30 In step ST2414 shown, data is sent and received between UE and gNB#1. The data transmission and reception in step ST2414 is performed while avoiding the transmission timing of PRACH and RAR between UE and gNB#2.

[0387] Fig.30 Steps ST2322 to ST2334 shown are Fig.28 same.

[0388] As another example, the activated base station may stop data transmission and reception between the UE and the activated base station during the random access process between the UE and the inactivated base station. The UE may notify the activated base station of the start of the random access process. The activated base station may use the notification to stop data transmission and reception with the UE. The UE may notify the activated base station of the end of the random access process. The activated base station may use the notification to restart data transmission and reception with the UE. Thus, for example, the random access process between the UE and the inactivated base station may be performed quickly.

[0389] The UE may use L1 / L2 signaling to send the notification to the activated base station. Thus, for example, the UE can quickly notify the notification. As another example, the UE may use MAC signaling to notify the notification. Thus, for example, the reliability of the notification can be ensured by HARQ retransmission control. As another example, the UE may use RRC signaling to notify the notification. Thus, for example, the UE can notify the activated base station of more information.

[0390] Fig.31 and Fig.32 This is a sequence diagram showing a third example of the operation of random access processing between a UE equipped with multiple SIMs and an inactive base station. Fig.31 and Fig.32 Connect at the boundary line BL3132. Fig.31 and Fig.32 In the example, the UE is connected to two NWs (NW#1 and NW#2), and is connected to gNB#1 to which NW#1 belongs and gNB#2 to which NW#2 belongs. Fig.31 and Fig.32 In , AMF#1 and AMF#2 exist under the subordinate of NW#1 and NW#2 respectively. Fig.31 and Fig.32 In the example shown, gNB#1 is an activated base station and gNB#2 is an inactive base station. Fig.31 and Fig.32 In, with Figure 16-17 , Figure 27-28 The same processing is assigned the same step numbers, and common descriptions are omitted.

[0391] Fig.31 Steps ST1601 to ST1603 shown are Fig.16 same. Fig.31 Steps ST2304 to ST2320 shown are Fig. 27 and Fig.28 same.

[0392] exist Fig.32 In step ST2520 shown, the UE uses the generation of data for gNB#2 as an opportunity to notify gNB#1 to start random access processing with gNB#2. The UE can use L1 / L2 signaling to make this notification, or it can use MAC signaling to make this notification, or it can use RRC signaling to make this notification. In step ST2521, gNB#1 stops sending and receiving with the UE.

[0393] Fig.32 Steps ST2322 to ST2332 shown are Fig.28 same.

[0394] exist Fig.32 In step ST2532 shown, the UE notifies gNB#1 that the random access process with gNB#2 is completed. The UE may use L1 / L2 signaling, MAC signaling, or RRC signaling to make the notification. In step ST2533, gNB#1 resumes transmission and reception with the UE.

[0395] Fig.32 Step ST2334 shown is the same as Fig.28 same.

[0396] As another example, the UE may request the activated base station to terminate the RRC connection with the base station, or request to release the RRC connection. The UE may use RRC signaling to make the request. The RRC signaling may be a newly set signaling, such as an RRC termination request (RRCSuspendRequest), or an RRC release request (RRCReleaseRequest). The activated base station may terminate the connection between the UE and the activated base station, or release the connection between the UE and the activated base station. The UE may start a random access process with the inactive base station after the connection with the activated base station is terminated or released. Thus, for example, the complexity of the communication system can be avoided.

[0397] Fig.33 and Fig.34 This is a sequence diagram showing a fourth example of the operation of random access processing between a UE equipped with multiple SIMs and an inactive base station. Fig.33 and Fig.34 Connect at the boundary line BL3334. Fig.33 and Fig.34 In the example, the UE is connected to two NWs (NW#1 and NW#2), and is connected to gNB#1 to which NW#1 belongs and gNB#2 to which NW#2 belongs. Fig.33 and Fig.34 In , AMF#1 and AMF#2 exist under the subordinate of NW#1 and NW#2 respectively. Fig.33 and Fig.34 In the example shown, gNB#1 is an activated base station and gNB#2 is an inactive base station. Fig.33 and Fig.34 An example of terminating the RRC connection between the UE and gNB#1 along with the generation of uplink data from the UE to gNB#2 is shown. Fig.33 and Fig.34 In, with Figure 16-17 , Figure 27-28 The same processing is assigned the same step numbers, and common descriptions are omitted.

[0398] Fig.33 Steps ST1601 to ST1603 shown are Fig.16 same. Fig.33 Steps ST2304 to ST2320 shown are Fig. 27 and Fig.28 same.

[0399] exist Fig.34 In step ST2620 shown, the UE requests gNB#1 to terminate the RRC connection. The UE can use RRC signaling to make the request. The RRC signaling can be a newly set signaling, such as an RRC termination request (RRCSuspendRequest).

[0400] exist Fig.34 In step ST2621 shown, gNB#1 indicates the termination of the RRC connection to the UE. For this indication from gNB#1 to the UE, RRC signaling, such as the RRC termination (RRCSuspend) disclosed in non-patent document 24 (TS 38.331), can be used. The UE can terminate the RRC connection with gNB#1 based on the termination indication of step ST2621. In step ST2622, the UE notifies gNB#1 of the completion of the RRC connection termination. For this notification from the UE to gNB#1, RRC signaling, such as the RRC termination completion (RRCSuspendComplete) disclosed in non-patent document 24 (TS 38.331), can be used.

[0401] After the RRC connection termination between UE and gNB#1 is completed, UE starts random access processing with gNB#2. Fig.34 Steps ST2322 to ST2332 shown are Fig.28 same.

[0402] Although in Fig.33 and 34 2 shows a case where the RRC connection between the UE and gNB#1 is terminated, but the RRC connection may be released. In step ST2620, the UE may request the release of the RRC connection from gNB#1. In step ST2621, gNB#1 may indicate the release of the RRC connection to the UE. In step ST2622, the UE may notify gNB#1 of the release of the RRC connection. Thus, for example, the memory usage in the UE can be reduced.

[0403] As another example, the UE may request the AMF connected to the activated base station to release the connection with the NW to which the activated base station is connected, or may request the termination of the connection. The UE may use NAS signaling to request the AMF to release or terminate. The AMF may use the request to release or terminate the connection with the UE. For example, the AMF may indicate the release of the RRC connection with the UE to the activated base station, or may indicate the termination of the RRC connection. The activated base station may use the indication to indicate the release or termination of the RRC connection to the UE. The UE may start random access processing with the non-activated base station after the connection with the NW is released. Thus, for example, the same effect as described above can be obtained.

[0404] According to the first modification, it is possible to secure time for random access processing between the UE and the inactive base station. As a result, it is possible to start or resume connection with the inactive base station.

[0405] Implementation 3 Embodiment 2 discloses a method for avoiding conflict between scheduling by an active base station and synchronization of an inactive base station. Embodiment 3 discloses a method for avoiding conflict in scheduling when a UE equipped with multiple SIMs communicates with active base stations of multiple NWs.

[0406] The timing at which communication is possible between the UE and the base station of each NW is allocated in a time-division manner.

[0407] The allocation may be performed by the UE. The UE may notify the base station of each NW of information related to the allocation. The base station of each NW may use the allocation to perform transmission and reception with the UE.

[0408] The UE may use RRC signaling to make the notification. Thus, for example, more information can be notified. As another example, the UE may use MAC signaling to make the notification. Thus, for example, the UE can quickly perform the notification. As another example, the UE may use L1 / L2 signaling to make the notification. Thus, for example, the UE can further quickly perform the notification.

[0409] Other solutions are disclosed. The allocation may be determined by a base station (hereinafter sometimes referred to as a determining base station). For example, the master NW disclosed in Embodiment 1 may determine the allocation. The base station of the master NW may notify the UE of the allocation.

[0410] The UE may notify the decision base station of the information required for the allocation decision. The UE may use RRC signaling, MAC signaling, L1 / L2 signaling, or a combination of the above for the notification. The decision base station may use the information to decide the allocation.

[0411] As examples of the information necessary for determining the allocation, the following (1) to (7) are disclosed.

[0412] (1) Information related to the identification of base stations of other NWs.

[0413] (2) Information related to the scheduling of base stations of other NWs.

[0414] (3) Information related to parameter sets of base stations of other NWs.

[0415] (4) Information related to the frame timing of the base stations of each NW.

[0416] (5) Information related to the timing of receiving synchronization signals, system information and / or paging from base stations of other NWs.

[0417] (6) Information related to random access processing between base stations of other NWs.

[0418] (7) A combination of the above (1) to (6).

[0419] The information in (1) above may be, for example, a base station identifier of a base station of another NW or a cell identifier. Thus, for example, the determining base station can grasp other base stations. As a result, the complexity associated with the allocation performed by the determining base station can be avoided.

[0420] The information in (2) above may be, for example, a control resource set (ControlResource SET; CORESET) allocated to the UE by a base station of another NW, or information related to scheduling dynamically allocated by the base station, or set scheduling (for example, semi-persistent scheduling and / or set permission), or information related to PUCCH allocation, or information related to SRS allocation. The determining base station may use the information in (2) above to determine the allocation. Thus, for example, scheduling conflicts between the determining base station and other base stations may be prevented.

[0421] The information in (3) above may be, for example, a subcarrier spacing, a time slot length, or a symbol length used by the UE in transmitting and receiving with base stations of other NWs, or may be a parameter μ disclosed in Section 4.2 of Non-Patent Document 13 (TS38.211). Thus, for example, in scheduling of activated base stations, the reliability of actions for avoiding synchronization signals from inactivated base stations can be improved.

[0422] The information of (4) above may be the same as the information of (4) disclosed as information for avoiding paging conflicts in Implementation 1. The information may also be, for example, information related to the difference in frame timing between the determining base station and the other base station. As another example, the information of (4) above may be a specified time point in each base station, for example, a time at the boundary of a specified SFN. Thus, for example, even when there is a frame offset between the determining base station and the other base station, scheduling conflicts between base stations can be avoided.

[0423] The information in (5) above may be the information in (1) to (9) disclosed as information related to the timing of the UE receiving the synchronization signal, system information and / or paging from the non-activated base station in Embodiment 2, with the non-activated base station replaced with a base station of another NW. Thus, for example, both data transmission and reception with one base station and reception of the synchronization signal, system information and / or paging from another base station (for example, reception of paging accompanied by system information update) can be implemented.

[0424] The information of (6) above may be the information of (1) to (8) disclosed as information related to random access processing with base stations of other NWs in variation 2 of implementation mode 1. Thus, for example, both data transmission and reception with one base station and random access processing with other base stations (for example, random access processing for requesting system information) may be implemented.

[0425] The base station may use RRC signaling to notify the allocation. Thus, for example, the base station can notify more information. As another example, the base station may use MAC signaling to notify. Thus, for example, the base station can quickly perform the notification. As another example, the base station may use L1 / L2 signaling to notify. Thus, for example, the base station can further quickly perform the notification.

[0426] The UE may notify the base station of the other NW of the allocation received from the decision base station. The UE may use RRC signaling to make the notification, or may use MAC signaling to make the notification, or may use L1 / L2 signaling to make the notification. The base station of the other NW may use the allocation to perform transmission and reception with the UE. Thus, for example, even between base stations of different NWs, it is possible to prevent conflicts in scheduling of the UE.

[0427] The base stations of other NWs can request the UE to change the allocation. The UE can notify the decision base station of the request. The decision base station can use the request to change the allocation. This can improve the efficiency of the communication system, for example.

[0428] Other solutions are disclosed. The decision base station may notify the base stations of other NWs of the allocation. An interface may be set between the decision base station and the base stations of other NWs. The interface may be via the UPF of each other NW. The decision base station may use the interface to notify the base stations of other NWs of the allocation.

[0429] Other solutions are disclosed. A default allocation mode may be set. The default mode may be stored, for example, in a SIM possessed by the UE. The UE may notify the base stations of each NW of the default mode. The base stations of each NW may use the default allocation to perform transmission and reception with the UE. Thus, for example, the complexity associated with conflict avoidance of scheduling for the UE between the base stations may be avoided.

[0430] Multiple default allocation modes may be set. For example, the multiple allocation modes may be set for each SIM. Priorities may be set for the multiple allocation modes. For example, in the case where the allocation modes set for each SIM compete with each other, any allocation mode may be prioritized. The UE may notify each base station of the allocation mode with a high priority. Thus, for example, complexity associated with conflict avoidance of scheduling for the UE between base stations may be avoided.

[0431] As another example, a default allocation mode may be set according to a standard. Thus, for example, conflict avoidance of scheduling for UEs between base stations may be performed quickly.

[0432] The method disclosed in this embodiment 3 can be used to avoid competition of UE capabilities. For example, in the case of competition between UE capabilities possessed by UE and each NW, a priority can be set for each capability. The priority can be provided statically, for example. Alternatively, the priority can be changed dynamically, for example, the UE capabilities of the main NW can be prioritized. Thus, for example, malfunction of the communication system caused by competition of UE capabilities can be prevented.

[0433] The above solutions can be combined. For example, the UE can notify the decision base station and the base stations of other NWs of the default allocation mode. The decision base station can use the allocation mode to change the allocation. The decision base station can notify the UE of information related to the changed allocation. The UE can notify the base stations of other NWs of information related to the changed allocation. The decision base station and the base stations of other NWs can use the changed allocation to send and receive with the UE. As a result, for example, the flexibility of scheduling of UEs at each base station can be improved.

[0434] According to the third embodiment, it is possible to avoid scheduling conflicts when a UE equipped with multiple SIMs communicates with multiple active base stations of NWs. As a result, the reliability of communication between the UE and the multiple base stations can be improved.

[0435] Modification 1 of Implementation Method 3 When a UE equipped with multiple SIMs communicates with activated base stations of multiple NWs, inter-NW preemption can be performed. Inter-NW preemption can be, for example, transceiving performed in such a way that time resources allocated for transceiving between the UE and one NW are reallocated for high-priority transceiving between the UE and other NWs.

[0436] Signaling for inter-NW preemption may be set between the UE and the base station.

[0437] A signal requesting inter-NW preemption may be set. For example, in the inter-NW preemption of the uplink, an SR for inter-NW preemption may be set. A PUCCH for communicating the SR may be set. By distinguishing resources on the time and / or frequency axis and / or number in the PUCCH for the SR and the PUCCH of the existing SR, the SR may be distinguished from the existing SR.

[0438] The notification of the signal from the UE to the base station can use, for example, L1 / L2 signaling, MAC signaling, or RRC signaling. In the case of L1 / L2 signaling, for example, the above-mentioned PUCCH can be set to use the PUCCH for notification. The PUCCH resources can be pre-set by the base station for the UE. By using L1 / L2 signaling, the request for preemption between NWs can be notified as early as possible.

[0439] For example, in the inter-NW preemption of the uplink, the UE may send an SR for the inter-NW preemption to the base station. The base station may be the object of the communication related to the inter-NW preemption. The SR may include information indicating that it is the inter-NW preemption. The information may, for example, be an identifier indicating that it is the inter-NW preemption. The information may also be, for example, information indicating the priority in the inter-NW preemption, such as information related to QoS. The information may, for example, be information related to the communicable timing of the preemption allocated by the UE.

[0440] The base station can use the SR to allocate frequency and / or time resources for inter-NW preemption to the UE. The base station can notify the UE of information related to the frequency and / or time resources allocated to the UE. The notification from the base station to the UE can be performed, for example, using L1 / L2 signaling, or using MAC signaling, or using RRC signaling. The notification from the base station to the UE can be a dynamic permission or a set permission. The UE can use the notification to perform inter-NW preemption communication with the base station.

[0441] In the allocation of the transmission and reception timing of the UE and each NW disclosed in Implementation Method 3, there may also be a period of repetition between NWs. The UE may, for example, apply the SR for the above-mentioned preemption between NWs during the repeated period. For example, the UE may send an SR for preemption between NWs to a NW base station. When sending the SR, the UE may not communicate with the base stations of other NWs. Alternatively, when the UE sends information related to the communicative timing for preemption allocated by the UE to the base station, the UE may not communicate with the base stations of other NWs during the timing. Thus, for example, the UE can quickly start NW preemption in the repeated period.

[0442] For example, the SR for inter-NW preemption may include information indicating communication with base stations of other NWs. The UE may send the SR to a NW base station. When sending the SR, the UE may communicate with base stations of other NWs instead of the base stations of the NW that sent the SR. Alternatively, when the UE sends information related to the communicative timing for preemption allocated by the UE to the base station, the UE may communicate with base stations of other NWs instead of the base stations of the NW that sent the SR during the timing. Thus, for example, the base station of the NW that receives the SR can recognize that the UE communicates with base stations of other NWs. Thus, it is not necessary to perform reception processing from the UE in the base station of the NW that receives the SR. The power consumption of the base station can be reduced.

[0443] During the above-mentioned repeated period, the base station can notify the UE of information related to the allocation of frequency and / or time resources. The UE can receive the information based on the above-mentioned SR transmission. When the UE receives the information, it may not perform transmission and reception with other NWs. Thus, for example, the base station can quickly notify the UE of the information.

[0444] During the above-mentioned repeated period, inter-NW preemptive communication can be performed from the UE to the base station. The UE can use the reception of the above-mentioned information related to the allocation of frequency and / or time resources as an opportunity to perform inter-NW preemptive communication with the base station. The base station can allocate inter-NW preemptive communication from the UE during the repeated period between NWs, and can also allocate inter-NW preemptive communication from the UE in the timing of transmission and reception allocation between the base station. When performing inter-NW preemptive communication, the UE may not perform transmission and reception with other NWs. As a result, for example, the UE can quickly perform high-priority uplink transmission to the base station.

[0445] Inter-NW preemption may be performed in downlink communications. The base station may notify the UE of the occurrence of downlink inter-NW preemption. The notification may be performed, for example, using L1 / L2 signaling, MAC signaling, or RRC signaling. The UE may use the notification to continue downlink reception from the base station. For example, the UE may not switch the transceiver facing the base station to a base station facing other NWs. As a result, for example, the UE is able to quickly receive high-priority downlink communications.

[0446] The UE may also perform a receiving action of downlink inter-NW preemption. The UE may perform the receiving action during an SS burst from a base station of another NW. For example, the UE may also perform the receiving action during a gap in an SS block constituting the SS burst. Thus, for example, the UE may receive downlink inter-NW preemption even while receiving a synchronization signal from another NW. As a result, the UE may quickly receive high-priority downlink communications.

[0447] The UE can notify the base station of each NW of the information required to determine the preemption between NWs. This information can be, for example, the same as the information (1) to (7) disclosed in Implementation Example 3 as the information required for determining the allocation of timing for communication with the base stations of each NW. The base station of each NW can use this information to determine whether the communication with the UE becomes preemptive communication between NWs. For example, the base station of each NW can use the information (4) above, that is, information related to the frame timing of the base station of each NW, to determine whether a scheduling conflict occurs with the base station of other NWs. The base station of each NW can determine that preemptive communication between NWs occurs when a scheduling conflict occurs with the base station of other NWs. Thus, for example, in a communication system, the occurrence of preemptive communication between NWs is minimized, thereby improving the efficiency of the communication system.

[0448] There may be communications that the UE can send and receive with any NW. The communications may be, for example, communications of emergency information, such as communications in a public warning system (PWS). The base stations of each NW may perform the communications with the UE respectively. Thus, for example, the UE can quickly receive the communications.

[0449] The UE may delete the communication that is received repeatedly. For example, the UE may use only the earliest received communication and delete the communication received after the second one. The communication may include an identifier indicating that it is the same information. The UE may use the identifier to detect the repetition of the communication. Thus, for example, redundant alarm reception in the UE can be prevented.

[0450] Other solutions are disclosed. Inter-NW preemption can be performed using the increase or decrease of transmission power. For example, inter-NW preemption can be a communication in which the transmission power of high-priority communication is set higher and the transmission power of low-priority communication is set lower. Inter-NW preemption using the increase or decrease of transmission power can be performed when the UE has multiple transceivers. As a result, for example, the reliability of higher-priority communication can be improved.

[0451] For example, in the inter-NW preemption of the uplink, the UE can increase the transmit power to send an SR for inter-NW preemption to the base station. The UE can reduce the transmit power to send to the base station of other NWs. The base station can use the SR to set the transmit power of the UE to be higher. The base station can use the SR to notify the UE of the scheduling permission for inter-NW preemption. The permission may include information related to the uplink transmit power. The UE can use the notification to increase the transmit power of the base station to perform inter-NW preemption communication.

[0452] According to the first modification, inter-NW preemption can be performed in a UE equipped with a plurality of SIMs, and as a result, QoS in the communication system can be satisfied.

[0453] Implementation 4 When a UE equipped with multiple SIM cards communicates with multiple base stations of a network, there is no known method for adjusting the power from the UE. As a result, the power used in transmission from the UE to each base station may be too high or too low.

[0454] In this fourth embodiment, a method for solving the above-mentioned problem is disclosed.

[0455] The UE may inform the base station of the power that the base station can transmit for each NW.

[0456] This power may be, for example, the power obtained by subtracting the sum of the transmission powers allocated to base stations of other NWs from the maximum power that the UE can transmit.

[0457] The maximum power that the UE can transmit may be different for each NW. The maximum power that the UE can transmit may be notified to the UE from the base station of each NW. In this case, the transmittable power for each NW of the UE may be determined, for example, as follows. When the maximum transmittable power for a certain NW that is the object of determining the transmittable power is set to Pa, and the power obtained by subtracting the total transmittable power allocated to other NWs other than the above-mentioned one NW from the maximum transmittable power of each NW is set to Pb, the smaller one of Pa and Pb may be determined as the transmittable power for the one NW. If transmittable power is not allocated for other NWs, the total transmittable power allocated for other NWs other than the above-mentioned one NW may be set to 0. Thus, for example, it is possible to prevent the UE from transmitting too much power to the one NW.

[0458] The UE can use RRC signaling to perform the notification. Thus, for example, the UE can notify each base station of more information.

[0459] As another example, the UE may use MAC signaling to perform the notification. Thus, for example, the UE can quickly perform the notification. The MAC signaling may be, for example, the same signaling as the PHR disclosed in non-patent document 17 (TS38.321).

[0460] As another example, the UE may use L1 / L2 signaling to perform the notification. Thus, for example, the UE can further quickly perform the notification.

[0461] The base station of each NW that receives the transmittable power from the UE can use the information of the transmittable power of the UE to perform scheduling for the UE for communication. The scheduling can be, for example, the amount of resources allocated on the frequency axis, information related to the transmit power of the UE, or information required for the UE to derive the transmit power. In this way, scheduling in which the power used in the transmission from the UE to each base station is too large or too small can be avoided.

[0462] When determining the transmittable power of a UE, a priority may be set between NWs. For example, the transmittable power of a UE may be determined starting from the NW with a higher priority. A specific example is disclosed in which the transmittable power for communication with a new NW (set as NW2) is determined after the transmittable power for an NW with a specified priority (set as NW1) has been determined. The UE compares the priority of NW1 with the priority of NW2, and when the priority of NW2 is higher, the transmittable power that has been determined for NW1 is discarded, and the transmittable power for NW2 is determined. Thereafter, the transmittable power for NW1 is determined again. When the priority of NW2 is lower, the transmittable power that has been determined for NW1 is used, and the transmittable power for NW2 is determined by the above method. In this way, the transmittable power can be preferentially allocated to the communication with the NW with a higher priority.

[0463] As another method, priority can be set for each service. Priority can be set for each service communicating in each NW. The priority of each service can be included in the QoS of the service, for example. Alternatively, in the case where information related to the priority already exists in the QoS, information related to the priority can also be used. The UE can use the priority of each service communicating in each NW to determine the transmittable power for each NW. As a method for determining the transmittable power, the above-mentioned transmittable power determination method can be applied. Transmitting power can be preferentially allocated to the NW that communicates for high-priority services.

[0464] When the UE redetermines the transmittable power for the NW, the UE can notify the base station of the NW of the redetermined transmittable power. The base station can use the notified transmittable power of the UE to implement scheduling. As a result, the base station of each NW can implement optimal scheduling for the UE. The utilization efficiency of the resources used in each NW can be improved.

[0465] A method for setting public priorities. For example, priorities can be set between NWs. As another method, priorities can be set for each service. Priorities can be pre-set to a unified value between NWs, or can be set to a unified value between services. Priorities can be provided in advance for NWs, or can be provided in advance for services. The priority of a service can be provided as QoS of a service. Priorities can be notified from each NW to the UE. For example, the priority can be notified when the UE performs registration processing with each NW. For example, the priority can be notified when the UE performs service request processing or PDU session establishment processing with each NW. For example, the priority can be set by the UE. For example, the priority can be set by a person. The method for setting priorities by the UE or a person can, for example, appropriately apply the method for setting the primary NW / secondary NW disclosed in Implementation Example 1. Thereby, the UE can identify the priority. In addition, the method for setting priorities disclosed here can also be appropriately applied in the above-mentioned implementation examples and variant examples.

[0466] There may be multiple transmittable powers for each NW. For example, the transmittable power may be set when the UE performs inter-NW preemptive communication with the NW. The transmittable power may also be set for the NW when the UE performs inter-NW preemptive communication with another NW different from the NW. Thus, for example, the reliability of inter-NW preemption may be improved.

[0467] The UE may notify the base station of each NW of the information related to the multiple powers. The UE may use RRC signaling to make the notification, or may use MAC signaling to make the notification, or may use L1 / L2 signaling to make the notification.

[0468] The base station of each NW can notify the UE of which of the multiple powers can be used to transmit power. The UE can use this information to derive the power that can be transmitted to the base station. The base station can use RRC signaling to notify the information. Thus, for example, the base station can notify the UE of more information. As another example, the base station can use MAC signaling to notify the information. Thus, for example, the base station can quickly notify the information. As another example, the base station can use L1 / L2 signaling to notify the information. Thus, for example, the base station can further quickly notify the information.

[0469] As another example, the base station of each NW may not notify the UE of information about which of the multiple powers can be used to transmit. For example, when the multiple powers are (a) the power that can be transmitted when the UE performs inter-NW preemption communication with the NW, (b) the power that can be transmitted when no NW preemption is performed, and (c) the power that the UE can transmit to the NW when performing inter-NW preemption communication with other NWs different from the NW, the information may not be notified from the base station to the UE. The UE can use information related to NW preemption obtained from the base station, such as information related to scheduling permission for NW preemption communication, to determine the power that can be transmitted to the base station. As another example, the UE can autonomously determine the transmittable power. For example, when the UE sends an SR for NW preemption communication to the base station of one NW, the UE can determine the power that can be transmitted to the base stations of each NW. Thus, for example, the amount of signaling between the base station and the UE can be reduced.

[0470] As another example of a case where multiple transmittable powers are set for the base station of each NW, the transmittable power can be set for each uplink channel. For example, for each of PUSCH, PUCCH, uplink RS and RACH, the transmittable power for the base station of each NW can be set. For each UCI contained in the PUCCH, the transmittable power for the base station of each NW can be set. For each uplink RS, for example, for each of SRS, DMRS, PRS, the transmittable power for the base station of each NW can be set. The UE can use the information of the transmittable power of each channel to perform uplink transmission. Thus, for example, the flexibility in the communication system can be improved.

[0471] Regarding the case where a plurality of transmittable powers are set for the base station of each NW, the above examples can be combined. For example, the transmittable power for each uplink channel can be different depending on whether the NW preempts the communication. Thus, for example, the reliability of the NW preempting the communication can be improved, and the flexibility in the communication system can be improved.

[0472] According to the fourth embodiment, the power used in transmission from UE to each base station can be adjusted appropriately.

[0473] The above-mentioned embodiments and their modifications are merely examples, and the embodiments and their modifications can be freely combined. In addition, arbitrary components of the embodiments and their modifications can be appropriately changed or omitted.

[0474] For example, in each of the above-mentioned embodiments and their variations, a subframe is an example of a time unit for communication in a fifth-generation base station communication system. It may also be a scheduling unit. In each of the above-mentioned embodiments and their variations, the processing described in subframe units may also be performed in TTI units, time slot units, sub-time slot units, and mini-time slot units.

[0475] The present disclosure has been described in detail, but the above description is in all aspects illustrative and not restrictive, and it is understood that numerous variations not shown in the examples are conceivable. Description of symbols

[0476] 200, 210 are communication systems, 202 are communication terminal devices, and 203 are base station devices.

Claims

1. A terminal device having multiple SIM cards, characterized in that: The terminal device is configured to connect to a plurality of networks using the plurality of SIMs (Subscriber Identity Modules). The terminal device is configured to determine a paging conflict between the plurality of networks.

2. The terminal device according to claim 1, characterized in that The terminal device is configured to perform steps for avoiding the paging conflict.

3. The terminal device according to claim 2, characterized in that The multiple networks include a first network and a second network, the first network includes an AMF (Access and Mobility Management Function: access / mobility management function), The terminal device is configured to send a first NAS (Non-Access Stream) signaling including information for avoiding the paging conflict with the second network to the AMF in the step.

4. The terminal device according to claim 3, characterized in that The information includes identification information for identifying the terminal device.

5. The terminal device according to claim 4, characterized in that The identification information is the 5G-GUTI (5G Globally Unique Temporary Identifier) ​​allocated by the AMF.

6. The terminal device according to claim 4, characterized in that The terminal device is configured to receive, in the step, from the AMF a second NAS signaling including the identification information changed by the AMF, The terminal device changes the timing of paging of the first network based on the changed identification information.

7. The terminal device according to claim 6, characterized in that The terminal device is configured to send a third NAS signaling indicating the end of the step to the AMF based on the reception of the second NAS signaling.

8. The terminal device according to claim 2, characterized in that The plurality of networks include a first network and a second network, The terminal device is configured to transmit, in the step, signaling including information for avoiding the paging conflict with the second network to the base station device in the first network.

9. A communication system comprising a terminal device, the terminal device having a plurality of SIMs (Subscriber Identity Modules), configured to connect to a plurality of networks using the plurality of SIMs, the communication system being characterized in that: The terminal device is configured to determine a paging conflict between the plurality of networks.

Images