Terminal device, base station device and communication system

Abstract

To enable quick network (NW) connections.SOLUTION: A terminal device has a plurality of SIMs (Subscriber Identity Modules) and is configured to connect to a plurality of networks using the plurality of SIMs. The plurality of networks include a first network and a second network, and the terminal device transmits, to a base station device of the first network, information indicating whether the terminal device receives paging from the first network.SELECTED DRAWING: Figure 14

Description

[Technical Field]

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

[0002] 3GPP (3rd Generation Partnership Project), a standardization organization for mobile communication systems, is considering a communication method called Long Term Evolution (LTE) for the wireless section and System Architecture Evolution (SAE) for the overall system configuration including the core network and radio access network (hereinafter collectively referred to as the network) (see, for example, Non-Patent Documents 1 to 5). This communication method is also called the 3.9G (3.9 Generation) system.

[0003] LTE uses OFDM (Orthogonal Frequency Division Multiplexing) for downlink and SC-FDMA (Single Carrier Frequency Division Multiple Access) for uplink as its access method. Unlike W-CDMA (Wideband Code Division Multiple Access), LTE does not include circuit switching and is only a packet communication method.

[0004] The decisions made by 3GPP regarding the frame configuration in the LTE system, as described in Non-Patent Document 1 (Chapter 5), will be explained using Figure 1. Figure 1 is an explanatory diagram showing the configuration of a radio frame used in an LTE communication system. In Figure 1, one radio frame is 10 ms. The radio frame is divided into 10 equally sized subframes. The subframe is divided into two equally sized slots. The first and sixth subframes of each radio frame include a downlink synchronization signal. The synchronization signals include a primary synchronization signal (P-SS) and a secondary synchronization signal (S-SS).

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

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

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

[0008] The Physical Downlink Control Channel (PDCCH) is a channel for downlink transmission from a base station to a communication terminal. The PDCCH reports resource allocation information for a Downlink Shared Channel (DL-SCH), which is one of the transport channels described below, resource allocation information for a Paging Channel (PCH), which is also one of the transport channels described below, and Hybrid Automatic Repeat reQuest (HARQ) information for the DL-SCH. The PDCCH carries an uplink scheduling grant. The PDCCH carries Acknowledgement (Ack) / Negative Acknowledgement (Nack), which are response signals to uplink transmissions. The PDCCH is also called an L1 / L2 control signal.

[0009] The Physical Downlink Shared Channel (PDSCH) is a channel for downlink transmission from a base station to a communication terminal. A Downlink Shared Channel (DL-SCH), which is a transport channel, and a PCH, which is also 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 communication terminals, and a multicast channel (MCH), which is a transport channel, is mapped to the PMCH.

[0011] The Physical Uplink Control Channel (PUCCH) is a channel for uplink transmission from a communication terminal to a base station. The PUCCH carries Ack / Nack, which are response signals to downlink transmissions. The PUCCH carries Channel State Information (CSI). The CSI consists of a Rank Indicator (RI), a Precoding Matrix Indicator (PMI), and a Channel Quality Indicator (CQI) report. The RI is information on the rank of the channel matrix in MIMO. The PMI is information on the precoding weight matrix used in MIMO. The CQI is quality information that indicates the quality of received data or the quality of the communication path. The PUCCH also carries a Scheduling Request (SR).

[0012] The Physical Uplink Shared Channel (PUSCH) is a channel for uplink transmission from a communication terminal to a base station. The 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. The PHICH carries Ack / Nack, which are response signals to uplink transmission. The Physical Random Access Channel (PRACH) is a channel for uplink transmission from a communication terminal to a base station. The PRACH carries a random access preamble.

[0014] Downlink reference signals (RS) are symbols known in LTE communication systems. The following five types of downlink reference signals are defined: Cell-specific Reference Signal (CRS), MBSFN Reference Signal, UE-specific reference signal Demodulation Reference Signal (DM-RS), Positioning Reference Signal (PRS), and Channel State Information Reference Signal (CSI-RS). Measurement of the physical layer of a communication terminal includes measurement of the reference signal received power (RSRP).

[0015] Similarly, the uplink reference signal is a symbol known in LTE communication systems. Two types of uplink reference signals are defined: a data demodulation reference signal (DM-RS) and a sounding reference signal (SRS).

[0016] The transport channels described in Non-Patent Document 1 (Chapter 5) will be explained below. Among the downlink transport channels, a broadcast channel (BCH) is broadcast to the entire coverage of the base station (cell). The BCH is mapped to a physical broadcast channel (PBCH).

[0017] Retransmission control using HARQ (Hybrid ARQ) is applied to the Downlink Shared Channel (DL-SCH). DL-SCH can be broadcast to the entire coverage of a base station (cell). DL-SCH supports dynamic or semi-static resource allocation. Semi-static resource allocation is also called persistent scheduling. DL-SCH supports discontinuous reception (DRX) in communication terminals to reduce power consumption of communication terminals. DL-SCH is mapped to the Physical Downlink Shared Channel (PDSCH).

[0018] The Paging Channel (PCH) supports DRX in communication terminals to enable low power consumption in communication terminals. The PCH is required to broadcast to the entire coverage of the base station (cell). The PCH is mapped to physical resources such as the Physical Downlink Shared Channel (PDSCH) that can be dynamically used for traffic.

[0019] The Multicast Channel (MCH) is used for broadcasting to the entire coverage of a base station (cell). The MCH supports SFN combining of MBMS (Multimedia Broadcast Multicast Service) services (MTCH and MCCH) in multi-cell transmission. The MCH supports semi-static resource allocation. The MCH is mapped to the PMCH.

[0020] Among the uplink transport channels, the Uplink Shared Channel (UL-SCH) is subject to retransmission control using HARQ (Hybrid ARQ). The UL-SCH supports dynamic or semi-static resource allocation. The UL-SCH is mapped to the Physical Uplink Shared Channel (PUSCH).

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

[0022] We will explain HARQ. HARQ is a technology that improves the communication quality of a transmission channel by combining Automatic Repeat reQuest (ARQ) and Forward Error Correction. HARQ has the advantage that error correction works effectively through retransmission even on transmission channels where communication quality varies. In particular, by combining the reception results of the initial transmission and the retransmission when retransmitting, it is possible to achieve further quality improvement.

[0023] An example of a retransmission method will be explained below. If the receiving side is unable to decode the received data correctly, in other words, if a CRC (Cyclic Redundancy Check) error occurs (CRC=NG), the receiving side will send a "Nack" to the sending side. The sending side, having received the "Nack," will retransmit the data. If the receiving side is able to decode the received data correctly, in other words, if no CRC error occurs (CRC=OK), the receiving side will send an "Ack" to the sending side. The sending side, having received the "Ack," will send the next data.

[0024] The logical channels described in Non-Patent Document 1 (Chapter 6) will be explained below. The Broadcast Control Channel (BCCH) is a downlink channel for broadcast system control information. The BCCH, which is a logical channel, is mapped to the broadcast channel (BCH) or the downlink shared channel (DL-SCH), which are transport channels.

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

[0026] A Common Control Channel (CCCH) is a channel for transmission control information between a communication terminal and a base station. CCCH is used when a communication terminal does not have an RRC connection with the network. In the downlink direction, CCCH is mapped to a Downlink Shared Channel (DL-SCH), which is a transport channel. In the uplink direction, CCCH is mapped to an Uplink Shared Channel (UL-SCH), which is a transport channel.

[0027] The Multicast Control Channel (MCCH) is a downlink channel for point-to-multipoint transmission. The MCCH is used to transmit MBMS control information for one or several MTCHs from the network to communication terminals. The MCCH is used only by communication terminals receiving MBMS. The MCCH is mapped to the Multicast Channel (MCH), which is a transport channel.

[0028] A dedicated control channel (DCCH) is a channel that transmits dedicated control information between a communication terminal and a network on a one-to-one basis. The DCCH is used when the communication terminal is in an RRC connection. The DCCH is mapped to an uplink shared channel (UL-SCH) in the uplink and to a downlink shared channel (DL-SCH) in the downlink.

[0029] A Dedicated Traffic Channel (DTCH) is a one-to-one communication channel for transmitting user information to an individual communication terminal. DTCH exists in both uplink and downlink. In uplink, DTCH is mapped to an uplink shared channel (UL-SCH) and in downlink, it is mapped to a downlink shared channel (DL-SCH).

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

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

[0032] The location of a communication terminal is tracked in units of an area consisting of one or more cells. Location tracking is performed to track the location of the communication terminal even when it is in standby mode and to enable the communication terminal to be called, in other words, to allow the communication terminal to receive calls. The area used for tracking the location of this communication terminal is called a tracking area.

[0033] 3GPP is also working on the development of the Long Term Evolution Advanced (LTE-A) standard as Release 10 (see Non-Patent Documents 3 and 4). LTE-A is based on the LTE wireless communication system, and is configured by adding several new technologies to it.

[0034] In the LTE-A system, carrier aggregation (CA) is being considered, which aggregates two or more component carriers (CCs) (also called "aggregation") to support wider frequency bandwidths (transmission bandwidths) up to 100 MHz. CA is described in Non-Patent Document 1.

[0035] When CA is configured, the UE has only one RRC connection with the network (NW). In the RRC connection, one serving cell provides NAS mobility information and security input. This cell is called the primary cell (PCell). In the downlink, the carrier corresponding to the PCell is the downlink primary component carrier (DL PCC). In the uplink, the carrier corresponding to the PCell is the uplink primary component carrier (UL PCC).

[0036] Depending on the UE's capabilities, a secondary cell (SCell) is configured to form a serving cell set together with the PCell. In the downlink, the carrier corresponding to the SCell is the downlink secondary component carrier (DL SCC). In the uplink, the carrier corresponding to the SCell is the uplink secondary component carrier (UL SCC).

[0037] A set of serving cells, which includes one PCell and one or more SCells, is configured for one UE.

[0038] Furthermore, new technologies for LTE-A include wider bandwidth extension and Coordinated Multiple Point transmission and reception (CoMP) technology. CoMP, which is being considered for LTE-A by 3GPP, is described in Non-Patent Document 1.

[0039] Furthermore, in order to handle future massive traffic volumes, 3GPP is considering using small eNBs (hereinafter sometimes referred to as "small-scale base station devices") that configure small cells. For example, technologies are being considered that aim to increase communication capacity by installing a large number of small eNBs and configuring a large number of small cells to improve frequency utilization efficiency. Specifically, there is dual connectivity (abbreviated as DC), in which a UE connects to two eNBs to communicate. DC is described in Non-Patent Document 1.

[0040] Of the eNBs that perform dual connectivity (DC), one may be referred to as a "master eNB (abbreviated as MeNB)" and the other as a "secondary eNB (abbreviated as SeNB)."

[0041] Mobile network traffic volume is on the rise, and communication speeds are also increasing. Once LTE and LTE-A are fully operational, communication speeds are expected to increase even further.

[0042] Furthermore, in response to the increasing sophistication of mobile communications, fifth-generation (hereinafter sometimes referred to as "5G") wireless access systems are being considered, with the goal of launching services after 2020. For example, in Europe, an organization called METIS has compiled requirements for 5G (see Non-Patent Document 5).

[0043] The requirements for a 5G wireless access system are that it will have 1,000 times the system capacity, 100 times the data transmission speed, one-tenth (1 / 10) the data processing delay, and 100 times the number of simultaneous connections of communication terminals compared to an LTE system, while also achieving further reductions in power consumption and lower equipment costs.

[0044] To meet these demands, 3GPP is currently working on 5G standards as Release 15 (see Non-Patent Documents 6 to 18). 5G wireless access technology is called "New Radio Access Technology" ("New Radio" is abbreviated as "NR").

[0045] The NR system is being developed based on the LTE system and LTE-A system, but the following changes and additions have been made to the LTE system and LTE-A system.

[0046] The NR access method uses OFDM in the downlink direction and OFDM and DFT-s-OFDM (DFT-spread-OFDM) in the uplink direction.

[0047] NR allows the use of higher frequencies than LTE in order to improve transmission speeds and reduce processing delays.

[0048] In NR, cell coverage is ensured by forming a narrow beam-shaped transmission and reception range (beamforming) and changing the direction of the beam (beam sweeping).

[0049] The NR frame structure supports various subcarrier spacings, i.e., various numerologies. In NR, regardless of the numerology, one subframe is 1 millisecond and one slot consists of 14 symbols. The number of slots included in one subframe is one in a numerology with a subcarrier spacing of 15 kHz, but increases in proportion to the subcarrier spacing in other numerologies (see Non-Patent Document 13 (TS38.211 V16.0.0)).

[0050] In NR, downlink synchronization signals are transmitted from base stations as synchronization signal bursts (hereinafter sometimes referred to as SS bursts) at predetermined intervals for a predetermined duration. SS bursts consist of synchronization signal blocks (hereinafter sometimes referred to as SS blocks) for each beam of the base station. The base station transmits the SS blocks of each beam within the duration of the SS burst, changing the beam. SS blocks consist of P-SS, S-SS, and PBCH.

[0051] In NR, the influence of phase noise is reduced by adding a Phase Tracking Reference Signal (PTRS) as a downlink reference signal for NR. PTRS is also added to the uplink reference signal, just like in the downlink.

[0052] In NR, slot format indication (SFI) has been added to the information contained in the PDCCH in order to flexibly switch between DL and UL within a slot.

[0053] In addition, in NR, the base station pre-configures a portion of the carrier frequency band (hereinafter sometimes referred to as the Bandwidth Part (BWP)) for the UE, and the UE transmits and receives data to and from the base station using this BWP, thereby reducing power consumption in the UE.

[0054] 3GPP is considering the following DC forms: DC by LTE base stations and NR base stations connected to EPC, DC by NR base stations connected to a 5G core system, and DC by LTE base stations and NR base stations connected to a 5G core system (see Non-Patent Documents 12, 16, and 19).

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

[0056] [Non-Patent Document 1] 3GPP TS 36.300 V16.0.0 [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

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[0057] The 3GPP is studying the operation of a UE using multiple SIMs. For example, they are studying measures to be taken when the timing of paging to the UE from two networks overlaps, and a method for notifying the type of data related to the paging (see Non-Patent Document 20). However, they have not disclosed a specific method for determining from which network a paging message should be received. As a result, for example, when paging messages for emergency communications such as an ETWS (Earthquake and Tsunami Warning System) or a CMAS (Commercial Mobile Alert System) are included among the paging messages that collide with each other, the UE may not be able to receive the paging message for the emergency communications. As a result, a problem occurs in that the UE cannot promptly receive the emergency communications.

[0058] In view of the above-mentioned problems, one of the objects of the present disclosure is to provide a technology that enables quick network connection. [Means for solving the problem]

[0059] A terminal device according to the present disclosure has a plurality of SIMs (Subscriber Identity Modules) and is configured to connect to a plurality of networks using the plurality of SIMs, the plurality of networks including a first network and a second network, and the terminal device is configured to transmit, to a base station device of the first network, information indicating whether the terminal device will receive paging from the first network. , the information indicating that a paging of a voice call is prioritized over a paging other than the paging of the voice call. It is characterized by: A base station device according to the present disclosure is a base station device in a communication system including a plurality of networks including a first network and a second network, and a terminal device having a plurality of SIMs (Subscriber Identity Modules) and configured to connect to the plurality of networks using the plurality of SIMs, wherein the first network includes the base station device, and the base station device is configured to receive, from the terminal device, information indicating whether the terminal device will receive paging from the first network. , the information indicating that a paging of a voice call is prioritized over a paging other than the paging of the voice call. It is characterized by: A communication system according to the present disclosure includes a plurality of networks including a first network and a second network, and a terminal device having a plurality of SIMs (Subscriber Identity Modules) and configured to connect to the plurality of networks using the plurality of SIMs, wherein the first network includes a base station device, and the terminal device is configured to transmit, to the base station device, information indicating whether the terminal device will receive paging from the first network. , the information indicating that a paging of a voice call is prioritized over a paging other than the paging of the voice call. It is characterized by: [Effects of the Invention]

[0060] According to the present disclosure, quick network connection is possible.

[0061] The objects, features, aspects, and advantages of the present disclosure will become more apparent from the following detailed description and the accompanying drawings. [Brief explanation of the drawings]

[0062] [Figure 1] FIG. 1 is an explanatory diagram showing the configuration of a radio frame used in an LTE communication system. [Figure 2] 1 is a block diagram showing the overall configuration of an LTE communication system 200 being discussed in 3GPP. [Figure 3] FIG. 2 is a block diagram showing the overall configuration of a communication system 210 conforming to the NR standard under discussion in 3GPP. [Figure 4] This is a diagram illustrating the configuration of DC using eNB and gNB connected to EPC. [Figure 5] This is a diagram of the DC configuration using gNB connected to the NG core. [Figure 6] This is a diagram illustrating the configuration of DC using eNB and gNB connected to the NG core. [Figure 7] This is a diagram illustrating the configuration of DC using eNB and gNB connected to the NG core. [Figure 8] FIG. 3 is a block diagram showing the configuration of a mobile terminal 202 shown in FIG. [Figure 9] FIG. 3 is a block diagram showing the configuration of a base station 203 shown in FIG. [Figure 10] FIG. 2 is a block diagram illustrating the configuration of an MME. [Figure 11] A block diagram showing the configuration of 5GC. [Figure 12] 1 is a flowchart showing an outline of operations from cell search to standby operation performed by a communication terminal (UE) in an LTE communication system. [Figure 13] FIG. 1 is a diagram illustrating an example of a cell configuration in an NR system. [Figure 14]FIG. 2 is an architecture diagram showing an example of connections between a UE with multiple SIMs and multiple NWs according to the first embodiment. [Figure 15] FIG. 10 is a diagram illustrating a first example of allocation of timing priorities of paging from multiple networks and paging received by a UE, in accordance with the first embodiment. [Figure 16] FIG. 10 is a diagram illustrating a second example of allocation of timing priorities of paging from multiple networks and paging received by a UE, in accordance with the first embodiment. [Figure 17] FIG. 11 is a sequence diagram showing an example of the operations of stopping and restarting RLF timers when a UE switches between a transmitting and receiving destination, according to the second embodiment. [Figure 18] FIG. 13 is a diagram illustrating an example of offsetting priority in a logical channel having a survival time requirement, in accordance with a first modification of the third embodiment. [Figure 19] FIG. 10 is a diagram illustrating an example of implicit control of the number of packet duplications in a logical channel having a survival time requirement, in accordance with a second modification of the third embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0063] Embodiment 1 Fig. 2 is a block diagram showing the overall configuration of an LTE communication system 200 being discussed in 3GPP. Fig. 2 will now be described. The radio access network is called E-UTRAN (Evolved Universal Terrestrial Radio Access Network) 201. A mobile terminal device (hereinafter referred to as "mobile terminal (User Equipment: UE)") 202, which is a communication terminal device, is capable of wireless communication with a base station device (hereinafter referred to as "base station (E-UTRAN NodeB: eNB)") 203, and transmits and receives signals via wireless communication.

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

[0065] If control protocols for mobile terminals 202, such as RRC (Radio Resource Control), and user planes (hereinafter sometimes referred to as U-Planes), such as PDCP (Packet Data Convergence Protocol), RLC (Radio Link Control), MAC (Medium Access Control), and PHY (Physical layer), terminate at base stations 203, 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 broadcasting, 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) broadcast, paging, cell reselection, mobility, etc. are performed. In RRC_CONNECTED, the mobile terminal has an RRC connection and can transmit and receive data with the network. In addition, in RRC_CONNECTED, handover (HO), measurement of neighbor cells, etc. are performed.

[0068] The base station 203 is configured by one or more eNBs 207. A system configured by the core network EPC (Evolved Packet Core) and the radio access network E-UTRAN 201 is called an EPS (Evolved Packet System). The core network EPC and the radio access network E-UTRAN 201 are sometimes collectively referred to as a "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. Multiple MME units 204 may be connected to one eNB 207. 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 eNB 207, which is a base station, and the mobile terminal (UE) 202. The MME unit 204 constitutes the EPC, which is a core network. The base station 203 constitutes the E-UTRAN 201.

[0071] Base station 203 may configure one cell or multiple cells. Each cell has a predetermined range as coverage, which is the range within which communication with mobile terminal 202 is possible, and performs wireless communication with mobile terminal 202 within the coverage. When one base station 203 configures multiple cells, each cell is configured to be able to communicate with mobile terminal 202.

[0072] Figure 3 is a block diagram showing the overall configuration of a 5G communication system 210 being discussed in 3GPP. The following describes Figure 3. The radio access network is referred to as a Next Generation Radio Access Network (NG-RAN) 211. The UE 202 is capable of wireless communication with an NR base station device (hereinafter referred to as an "NR base station (NG-RAN NodeB: gNB)") 213, and transmits and receives signals via wireless communication. The core network is referred to as a 5G Core (5GC).

[0073] If control protocols for UE202, such as RRC (Radio Resource Control), and user planes (hereinafter sometimes referred to as U-Planes), such as SDAP (Service Data Adaptation Protocol), PDCP (Packet Data Convergence Protocol), RLC (Radio Link Control), MAC (Medium Access Control), and PHY (Physical layer), terminate at an NR base station 213, 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 the UE 202 and the NR base station 213 is the same as that of LTE. The states of the NR base station 213 and the UE 202 in the RRC include RRC_IDLE, RRC_CONNECTED, and RRC_INACTIVE.

[0075] RRC_IDLE and RRC_CONNECTED are the same as those in the LTE system. RRC_INACTIVE maintains the connection between the 5G core and the NR base station 213, and performs system information (SI), paging, cell reselection, mobility, and the like.

[0076] The gNB 217 is connected to an AMF / SMF / UPF unit (hereinafter sometimes referred to as the "5GC unit") 214, which includes an Access and Mobility Management Function (AMF), a Session Management Function (SMF), or a User Plane Function (UPF), or an AMF, SMF, and UPF, via an NG interface. Control information and / or user data are communicated between the gNB 217 and the 5GC unit 214. The NG interface is a collective term for the N2 interface between the gNB 217 and the AMF, the N3 interface between the gNB 217 and the UPF, the N11 interface between the AMF and the SMF, and the N4 interface between the UPF and the SMF. Multiple 5GC units 214 may be connected to one gNB 217. The gNBs 217 are connected to each other via an Xn interface, and control information and / or user data are communicated between the gNBs 217.

[0077] The NR base station 213 may configure one or more cells, similar to the base station 203. When one NR base station 213 configures multiple cells, each cell is configured to be able to communicate with the UE 202.

[0078] The gNB 217 may be divided into a central unit (hereinafter, sometimes referred to as a CU) 218 ​​and distributed units (hereinafter, sometimes referred to as DUs) 219. One CU 218 is configured in the gNB 217. One or more DUs 219 are configured in the gNB 217. The CU 218 is connected to the DU 219 via an F1 interface, and control information and / or user data is communicated between the CU 218 and the DU 219.

[0079] A 5G communication system may include a Unified Data Management (UDM) function and a Policy Control Function (PCF) described in Non-Patent Document 27 (3GPP TS23.501 V16.3.0). The UDM and / or PCF may be included in the 5GC unit in FIG.

[0080] A 5G communication system may include a Non-3GPP Interworking Function (N3IWF) described in Non-Patent Document 27 (3GPP TS23.501 V16.3.0). The N3IWF may terminate an Access Network (AN) between the UE and the N3IWF in non-3GPP access between the UE and the N3IWF.

[0081] Fig. 4 is a diagram showing a DC configuration by eNBs and gNBs connected to EPC. In Fig. 4, solid lines indicate U-Plane connections, and dashed lines indicate C-Plane connections. In Fig. 4, eNB223-1 serves as the master base station, and gNB224-2 serves as the secondary base station (this DC configuration may be referred to as EN-DC). Fig. 4 shows an example in which U-Plane connection between MME unit 204 and gNB224-2 is made via eNB223-1, but it may also be made directly between MME unit 204 and gNB224-2.

[0082] Figure 5 is a diagram showing the configuration of DC by a gNB connected to an NG core. In Figure 5, solid lines indicate U-Plane connections, and dashed lines indicate C-Plane connections. In Figure 5, gNB 224-1 is the master base station, and gNB 224-2 is the secondary base station (this DC configuration may be referred to as NR-DC). Figure 5 shows an example in which U-Plane connection between 5GC unit 214 and gNB 224-2 is made via gNB 224-1, but it may also be made directly between 5GC unit 214 and gNB 224-2.

[0083] Figure 6 is a diagram showing a DC configuration by eNB and gNB connected to the NG core. In Figure 6, solid lines indicate U-Plane connections, and dashed lines indicate C-Plane connections. In Figure 6, eNB226-1 is the master base station, and gNB224-2 is the secondary base station (this DC configuration may be referred to as NG-EN-DC). Figure 6 shows an example in which U-Plane connection between 5GC unit 214 and gNB224-2 is made via eNB226-1, but it may also be made directly between 5GC unit 214 and gNB224-2.

[0084] Figure 7 is a diagram showing another configuration of DC by eNB and gNB connected to the NG core. In Figure 7, solid lines indicate U-Plane connections, and dashed lines indicate C-Plane connections. In Figure 7, gNB224-1 is the master base station, and eNB226-2 is the secondary base station (this DC configuration may be referred to as NE-DC). Figure 7 shows an example in which U-Plane connection between 5GC unit 214 and eNB226-2 is made via gNB224-1, but it may also be made directly between 5GC unit 214 and eNB226-2.

[0085] FIG. 8 is a block diagram showing the configuration of mobile terminal 202 shown in FIG. 2. The transmission process of mobile terminal 202 shown in FIG. 8 will be described. First, control data from protocol processing unit 301 and user data from application unit 302 are stored in transmission data buffer unit 303. The data stored in transmission data buffer unit 303 is passed to encoder unit 304, where it is subjected to encoding processes such as error correction. Some data may be output directly from transmission data buffer unit 303 to modulation unit 305 without being encoded. The data encoded by encoder unit 304 is modulated by modulation unit 305. Precoding in MIMO may be performed by modulation unit 305. The modulated data is converted into a baseband signal, and then output to frequency conversion unit 306, where it is converted into a radio transmission frequency. Thereafter, a transmission signal is transmitted to base station 203 from antennas 307-1 to 307-4. Although FIG. 8 illustrates an example in which the number of antennas is four, the number of antennas is not limited to four.

[0086] Furthermore, the reception process of mobile terminal 202 is performed as follows. Radio signals from base station 203 are received by antennas 307-1 to 307-4. The received signals are converted from a radio reception frequency to a baseband signal by frequency conversion unit 306, and demodulated by demodulation unit 308. Demodulation unit 308 may also perform weight calculation and multiplication processing. The demodulated data is passed to decoder unit 309, where decoding processing such as error correction is performed. Of the decoded data, control data is passed to protocol processing unit 301, and user data is passed to application unit 302. A series of processes of mobile terminal 202 is controlled by control unit 310. Therefore, although control unit 310 is omitted in FIG. 8, it is connected to each unit 301 to 309. In FIG. 8, the number of antennas used by mobile terminal 202 for transmission and the number of antennas used for reception may be the same or different.

[0087] 2. The transmission process of the base station 203 shown in FIG. 9 will be described. The EPC communication unit 401 transmits and receives data between the base station 203 and the EPC (such as the MME unit 204). The 5GC communication unit 412 transmits and receives data between the base station 203 and the 5GC (such as the 5GC unit 214). The other base station communication unit 402 transmits and receives data with other base stations. The EPC communication unit 401, the 5GC communication unit 412, and the other base station communication unit 402 each exchange information with the protocol processing unit 403. 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 unit 402 are stored in the transmission data buffer unit 404.

[0088] The data stored in transmission data buffer unit 404 is passed to encoder unit 405, where it undergoes encoding processing such as error correction. Some data may be output directly from transmission data buffer unit 404 to modulation unit 406 without undergoing encoding processing. The encoded data is modulated by modulation unit 406. MIMO precoding may be performed by modulation unit 406. The modulated data is converted into a baseband signal, and then output to frequency conversion unit 407, where it is converted into a radio transmission frequency. Thereafter, a transmission signal is transmitted to one or more mobile terminals 202 from antennas 408-1 to 408-4. Although FIG. 9 illustrates an example in which the number of antennas is four, the number of antennas is not limited to four.

[0089] The reception process of the base station 203 is performed as follows: A radio signal from one or more mobile terminals 202 is received by an antenna 408. The received signal is converted from a radio reception frequency to a baseband signal by a frequency conversion unit 407, and demodulated by a demodulation unit 409. The demodulated data is passed to a decoder unit 410, where decoding processes such as error correction are performed. Of the decoded data, control data is passed to the protocol processing unit 403, the 5GC communication unit 412, the EPC communication unit 401, or the other base station communication unit 402, and user data is passed to the 5GC communication unit 412, the EPC communication unit 401, and the other base station communication unit 402. A series of processes of the base station 203 is controlled by a control unit 411. Therefore, although the control unit 411 is omitted in FIG. 9, it is connected to each unit 401 to 410. In FIG. 9, the number of antennas used for transmission by the base station 203 and the number of antennas used for reception may be the same or different.

[0090] 9 is a block diagram showing the configuration of base station 203, but a similar configuration may also be used for base station 213. In addition, in FIGS. 8 and 9, the number of antennas in mobile terminal 202 and the number of antennas in base station 203 may be the same or different.

[0091] 10 is a block diagram showing the configuration of an MME. FIG. 10 shows the configuration of an MME 204a included in the MME unit 204 shown in FIG. 2 described above. A PDN GW communication unit 501 transmits and receives data between the MME 204a and a PDN GW. A base station communication unit 502 transmits and receives data via the S1 interface between the MME 204a and a base station 203. If the data received from the PDN GW is user data, the user data is passed from the PDN GW communication unit 501 to the base station communication unit 502 via a user plane communication unit 503, and transmitted to one or more base stations 203. If the data received from the base station 203 is user data, the user data is passed from the base station communication unit 502 to the PDN GW communication unit 501 via the user plane communication unit 503, and transmitted to the PDN GW.

[0092] If the data received from the PDN GW is control data, the control data is passed from the PDN GW communication unit 501 to the control plane control unit 505. If the data received from the base station 203 is control data, the control data is passed 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 overall processing for the control plane (hereinafter sometimes referred to as the C-Plane). The NAS security unit 505-1 performs security for NAS (Non-Access Stratum) messages, etc. The SAE bearer control unit 505-2 performs management of SAE (System Architecture Evolution) bearers, etc. The idle state mobility management unit 505-3 performs mobility management in the idle state (also referred to as the LTE-IDLE state or simply idle), generation and control of paging signals in the idle state, addition, deletion, update, and search of tracking areas for one or more mobile terminals 202 under its control, tracking area list management, etc.

[0094] The MME 204a distributes paging signals to one or more base stations 203. The MME 204a also performs mobility control in an idle state. The MME 204a manages a tracking area list when the mobile terminal is in an idle state and an active state. The MME 204a initiates a paging protocol by transmitting a paging message to a cell belonging to a tracking area in which the UE is registered. The idle state mobility management unit 505-3 may manage the CSG, CSG ID, and whitelist of the eNB 207 connected to the MME 204a.

[0095] FIG. 11 is a block diagram showing the configuration of 5GC. FIG. 11 shows the configuration of the 5GC unit 214 shown in FIG. 3 described above. FIG. 11 shows a case where the 5GC unit 214 shown in FIG. 5 includes an AMF configuration, an SMF configuration, and a UPF configuration. The Data Network communication unit 521 transmits and receives data between the 5GC unit 214 and the Data Network. The base station communication unit 522 transmits and receives data via the S1 interface between the 5GC unit 214 and the base station 203, and / or the NG interface between the 5GC unit 214 and the base station 213. If the data received from the Data Network is user data, the user data is passed from the Data Network communication unit 521 to the base station communication unit 522 via the user plane communication unit 523, and transmitted to one or more base stations 203 and / or base stations 213. If the data received from base station 203 and / or base station 213 is user data, the user data is passed from base station communication unit 522 to data network communication unit 521 via user plane communication unit 523 and transmitted to the data network.

[0096] If the data received from the Data Network is control data, the control data is passed from the Data Network communication unit 521 to the session management unit 527 via the user plane communication unit 523. The session management unit 527 passes the control data to the control plane control unit 525. If the data received from the base station 203 and / or base station 213 is control data, the control data is passed from the base station communication unit 522 to the control plane control unit 525. The control plane control unit 525 passes 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 mobility management unit 525-3, etc., and performs overall processing for the control plane (hereinafter sometimes referred to as the C-Plane). The NAS security unit 525-1 performs security for NAS (Non-Access Stratum) messages, etc. The PDU session control unit 525-2 performs management of PDU sessions between the mobile terminal 202 and the 5GC unit 214, etc. The idle state mobility management unit 525-3 performs mobility management in the idle state (also referred to as the RRC_IDLE state or simply idle), generation and control of paging signals in the idle state, addition, deletion, update, and search of tracking areas for one or more mobile terminals 202 under its control, tracking area list management, etc.

[0098] The 5GC unit 214 distributes paging signals to one or more base stations 203 and / or base station 213. The 5GC unit 214 also performs mobility control in an idle state. The 5GC unit 214 manages a tracking area list when the mobile terminal is in an idle state, an inactive state, or an active state. The 5GC unit 214 initiates a paging protocol by transmitting a paging message to a cell belonging to a tracking area in which the UE is registered.

[0099] Next, an example of a cell search method in a communication system is shown. Fig. 12 is a flowchart showing an outline of the process from cell search to standby operation performed by a communication terminal (UE) in an LTE communication system. When the communication terminal starts a cell search, in step ST601, it synchronizes slot timing and frame timing using a primary synchronization signal (P-SS) and a secondary synchronization signal (S-SS) transmitted from a surrounding base station.

[0100] P-SS and S-SS are collectively called the Synchronization Signal (SS). The Synchronization Signal (SS) is assigned a synchronization code that corresponds one-to-one to the PCI assigned to each cell. 504 different PCIs are being considered. These 504 different PCIs are used to achieve synchronization and to detect (identify) the PCI of the synchronized cell.

[0101] Next, in step ST602, for the synchronized cell, a cell-specific reference signal (CRS), which is a reference signal (RS) transmitted from the base station for each cell, is detected and the RS received power (Reference Signal Received Power: RSRP) is measured. The RS uses a code that has a one-to-one correspondence with the PCI. By correlating with this code, it is possible to separate the cell from other cells. By deriving the code for the RS of the cell from the PCI identified in step ST601, it is possible to detect the RS and measure the RS received power.

[0102] Next, in step ST603, the cell with the best RS reception quality, for example, the cell with the highest RS reception power, that is, the best cell, is selected from 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 BCCH, which is broadcast information. A MIB (Master Information Block), which includes cell configuration information, is mapped to the BCCH on the PBCH. Therefore, the MIB can be obtained by receiving the PBCH and obtaining the BCCH. Examples of MIB information include the DL (downlink) system bandwidth (also called transmission bandwidth configuration: dl-bandwidth), the number of transmitting antennas, and the SFN (System Frame Number).

[0104] Next, in step ST605, the DL-SCH of the cell is received based on the cell configuration information in the MIB, and SIB (System Information Block) 1 is obtained from the broadcast information BCCH. SIB 1 includes information on access to the cell, information on cell selection, and scheduling information for other SIBs (SIBk; k is an integer greater than or equal to 2). SIB 1 also includes a tracking area code (TAC).

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

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

[0107] In the example shown in Fig. 12, an example of operations from cell search to standby in the LTE system is shown, but in the NR system, in addition to the best cell, the best beam may be selected in step ST603. Also, in the NR system, beam information, for example, a beam identifier, may be acquired in step ST604. Also, in the NR system, scheduling information of remaining minimum SI (RMSI) may be acquired in step ST604. In the NR system, RMSI may be received in step ST605.

[0108] An apparatus constituting a core network (hereinafter sometimes referred to as a "core network side apparatus") updates the tracking area list based on the identification number (e.g., UE-ID) of the communication terminal sent from the communication terminal together with a TAU request signal. The core network side apparatus transmits 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 operation in the cell.

[0109] The widespread use of smartphones and tablet devices has led to an explosive increase in cellular wireless communication traffic, raising concerns about a shortage of wireless resources worldwide. In response to this, efforts are being made to develop small cells and promote spatial separation in order to improve frequency utilization efficiency.

[0110] In a conventional cell configuration, a cell configured by an eNB has a relatively wide coverage area. Conventionally, a cell is configured so that a certain area is covered by the relatively wide coverage areas of multiple cells configured by multiple eNBs.

[0111] In the case of small cell configuration, a cell configured by an eNB has a narrower coverage area than a cell configured by a conventional eNB. Therefore, as in the past, a larger number of small cell configuration eNBs are required to cover a certain area compared to conventional eNBs.

[0112] In the following description, a cell with a relatively large coverage, such as a cell configured by a conventional eNB, is referred to as a "macro cell," and an eNB that configures the macro cell is referred to as a "macro eNB." Also, a cell with a relatively small coverage, such as a cell configured as a small cell, is referred to as a "small cell," and an eNB that configures the small cell is referred to as a "small eNB."

[0113] The macro eNB may be, for example, a "Wide Area Base Station" as described in Non-Patent Document 7.

[0114] The small eNB may be, for example, a low-power node, a local area node, a hotspot, etc. Also, the small eNB may be a pico eNB constituting a pico cell, a femto eNB constituting a femto cell, a HeNB, a remote radio head (RRH), a remote radio unit (RRU), a remote radio equipment (RRE), or a relay node (RN). Also, the small eNB may be a "local area base station" or a "home base station" as described in Non-Patent Document 7.

[0115] FIG. 13 shows an example of a cell configuration in NR. In an NR cell, narrow beams are formed and transmitted while changing direction. In the example shown in FIG. 13, at a certain time, base station 750 transmits and receives signals to and from a mobile terminal using beam 751-1. At another time, base station 750 transmits and receives signals to and from a mobile terminal using beam 751-2. In a similar manner, base station 750 transmits and receives signals to and from a mobile terminal using one or more of beams 751-3 to 751-8. In this way, base station 750 configures a wide-area cell.

[0116] 13 shows an example in which the number of beams used by the base station 750 is 8, but the number of beams may be different from 8. Also, in the example shown in FIG. 13, the number of beams used simultaneously by the base station 750 is 1, but it may be multiple.

[0117] A UE may be connected to or connectable to multiple networks. Hereinafter, "connected" may include not only an actual connected state but also a connectable state. A UE may connect to multiple networks using multiple SIMs. The UE may have only one pair of transceivers or multiple pairs of transceivers. The multiple networks may be PLMNs, non-public networks (NPNs), or private networks. Connections to the multiple networks may be made in parallel.

[0118] With respect to the connection between the UE and each NW, the RRC state of the UE may be the RRC_CONNECTED state, the RRC_INACTIVE state, or the RRC_IDLE state. The CM state of the UE may be the CM-IDLE state or the CM-CONNECTED state. The UE may be in the RRC_CONNECTED state or the CM-CONNECTED state for two or more of the multiple NWs to which it is connected. As another example, the UE may be in the RRC_CONNECTED state or the CM-CONNECTED state for only one of the multiple NWs to which it is connected.

[0119] 14 is an architecture diagram showing an example of a connection between a UE that uses multiple SIMs (hereinafter, sometimes referred to as a multi-SIM UE) and multiple networks. In FIG. 14, the multi-SIM UE is connected in parallel to NW#1 and NW#2.

[0120] In the example shown in FIG. 14, UE 1400 connects to gNB 1401 in NW #1. UE 1400 also connects to gNB 1411 in NW #2. gNB 1401 connects to AMF 1402 and UPF 1403 in NW #1. SMF 1404 in NW #1 connects to AMF 1402 and UPF 1403. gNB 1411 connects to AMF 1412 and UPF 1413 in NW #2. SMF 1414 in NW #2 connects to AMF 1412 and UPF 1413.

[0121] 14 shows an example in which UE 1400 is connected to two NWs, but UE 1400 may be connected to three or more NWs. Furthermore, one or more of the two NWs connected to UE 1400 may be NPNs. The same may be true when UE 1400 is connected to three or more NWs.

[0122] In a UE connected to multiple networks in parallel, overlapping of paging timings may occur (hereinafter, sometimes referred to as paging collision). A UE in which paging collision occurs may have only one pair of transceivers. In this case, the UE can only receive paging from one of the networks. Therefore, for example, if paging for emergency communication such as ETWS or CMAS is included among the pagings that collide with each other, the UE may not be able to receive the paging for the emergency communication. As a result, a problem occurs in that the UE cannot receive the emergency communication promptly.

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

[0124] Priorities are assigned to timings at which paging may be transmitted, which may hereinafter be referred to as timing priorities. Priorities are assigned to types of paging, which may hereinafter be referred to as type priorities.

[0125] The timing priority may be, for example, two levels, or three or more levels. A parameter relating to the timing priority may be provided.

[0126] The type priority may be, for example, two levels, or three or more levels. A parameter relating to the type priority may be provided.

[0127] Timing priority and type priority are associated with each other. For example, when both timing priority and type priority are configured in two stages, high timing priority may be associated with high type priority, and low timing priority may be associated with low type priority. Paging with a predetermined type priority may be transmitted at paging timing with a predetermined timing priority. For example, at a certain paging transmission timing, paging with a type priority equal to or lower than the timing priority may be transmitted. When paging timings from base stations of multiple networks collide, the UE may receive a paging with a high timing priority among the colliding pages. The UE may switch the destination network when receiving a paging with a high timing priority. The connection between the UE and the base station of the destination network may be RRC_CONNECTED, RRC_INACTIVE, or RRC_IDLE. This allows the UE to receive, for example, emergency communication-related paging with priority over other paging.

[0128] As another example, a high type priority may be sent with a low timing priority. The above operation may be applied, for example, when a paging message with a certain timing priority cannot be received due to a timing conflict with a paging message with a higher timing priority from another network. This allows, for example, the paging message with the certain timing priority to be received quickly in the above case.

[0129] The UE may expect that a paging with a type priority equal to or lower than the timing priority at the paging timing will be transmitted. That is, the UE may expect that a paging with a type priority higher than the timing priority at the paging timing will not be transmitted. In the above, a type priority equal to or lower than the timing priority may be a type priority lower than the timing priority, and a paging with a type priority higher than the timing priority may be a paging with a type priority equal to or higher than the timing priority.

[0130] As an example of timing priority allocation, when timing priority is divided into two stages, high timing priority and low timing priority may be alternately allocated for each PF (Paging Frame), high timing priority and low timing priority may be alternately allocated for each PO (Paging Occasion), or high timing priority and low timing priority may be alternately allocated for each PDCCH monitoring occasion used for paging reception.

[0131] The paging to which a type priority is assigned may be a paging for downlink data or a paging for a voice call. The voice call paging may be a paging for a normal incoming call or a paging for a voice call returned from a voice call for an emergency call. As another example, the paging to which a type priority is assigned may be a paging for an SI update or a paging for an emergency call. The emergency call may be, for example, a PWS (Public Warning System). The emergency call may be, for example, an ETWS (Earthquake and Tsunami Warning System), a CMAS (Commercial Mobile Alert System), an EU-ALERT (European Public Warning System), a KPAS (Korean Public Alert System), or another emergency call.

[0132] An emergency communication system for a private network (or a non-public network) may be provided. The emergency communication system for a private network may be included in the emergency communication system described above. This enables, for example, prompt notification to a UE of a problem occurring within a premises where a private network is used.

[0133] As an example of the assignment of type priority, when there are two levels of type priority, a high priority may be assigned to emergency communication and SI update paging, and a low priority may be assigned to other paging. As another example, when there are three levels of type priority, a high priority may be assigned to emergency communication, a medium priority may be assigned to SI update and voice calls, and a low priority may be assigned to other paging.

[0134] The number of stages of the timing priority and the type priority may be the same. This makes it possible to avoid complexity in associating the timing priority and the type priority, for example. As another example, the number of stages of the timing priority and the type priority may be different. This makes it possible to improve flexibility in associating the timing priority and the type priority, for example.

[0135] A timing priority may be assigned for each PF (Paging Frame). This allows, for example, a network device to assign timing priorities with a small amount of processing. As another example, a timing priority may be assigned for each PO (Paging Occasion). This allows, for example, improved flexibility in assigning timing priorities. As another example, a timing priority may be assigned for each PDCCH monitoring occasion used for paging reception. This allows, for example, further improved flexibility in assigning timing priorities.

[0136] As another example, timing priorities may be assigned for each DRX cycle, which may reduce the amount of processing required for timing priority assignment, for example.

[0137] The allocation of timing priorities may be determined by standards, which may allow, for example, avoiding design complexity in communication systems.

[0138] As another example, the core NW may determine the allocation of timing priorities. This enables, for example, improved flexibility in the allocation of timing priorities. The core NW may be, for example, an AMF or a PCF. The core NW may notify a base station of information regarding the determined allocation. The base station may notify the UE of the information regarding the allocation individually or may broadcast the information. As another example of notifying the information regarding the allocation, the core NW may notify the UE directly. For example, the AMF may notify the UE of the information using NAS signaling.

[0139] As another example of the allocation of timing priorities, the base station may determine the allocation, which may, for example, allow for further flexibility in the allocation of timing priorities. The base station may notify or broadcast information about the allocation to the UE individually.

[0140] A parameter for determining timing priority may be provided. The parameter may be, for example, a parameter using a UE identifier, or may be a parameter similar to the PCCH configuration information (PCCH-Config) disclosed in Non-Patent Document 22 (TS38.331). A method for determining timing priority from the parameter may be defined by a standard. This may, for example, reduce the size of notification of information necessary for determining timing priority.

[0141] The value of the parameter may be determined by each NW and notified to the UE. The notification may be performed via a base station. As another example, the value of the parameter may be determined by a base station and notified or broadcast to the UE. As another example, the value of the parameter may be determined for each cell.

[0142] An average value of timing priority may be set. For example, the average value may be the same between networks or between base stations. This makes it possible to prevent, for example, UEs from receiving paging messages from a specific network.

[0143] As another example, the average value may differ between networks. This allows, for example, adjustment between networks regarding the ease of UE paging reception. As another example, the average value may differ between base stations. This allows, for example, adjustment between base stations regarding the ease of UE paging reception.

[0144] As with the allocation of timing priorities, the average value of timing priorities may be determined by a standard, by the core network, or by the base station.

[0145] The following (1) to (8) are disclosed as examples of information regarding allocation of timing priority that the core NW and / or base station notifies or broadcasts to the UE.

[0146] (1) Information about the number of stages of timing priority.

[0147] (2) Timing priority value.

[0148] (3) Information about paging timing.

[0149] (4) Information about timing priority allocation patterns.

[0150] (5) Information about the period of timing priority assignment.

[0151] (6) Reference paging timing.

[0152] (7) Information for determining paging timing for each timing priority.

[0153] (8) A combination of (1) to (7) above.

[0154] The number of stages in the above (1) may be, for example, 2 or 3 or more. For example, when no timing priority is assigned, the number of stages in the above (1) may be 1. The UE may obtain the number of stages of timing priority using the information in the above (1). This may reduce the amount of processing required for the UE to grasp the assignment of timing priority, for example.

[0155] The information in (2) above may be, for example, information indicating whether the priority is high or low when the number of stages in (1) above is 2. The UE may obtain the timing priority using the information in (2) above. This may, for example, reduce the amount of processing required for the UE to grasp the allocation of timing priorities.

[0156] The above-mentioned information (3) may be, for example, information indicating the ordinal number of a PF among PFs within a DRX cycle. Alternatively, the above-mentioned information (3) may be, for example, information indicating the ordinal number of a PO among POs within a PF. Alternatively, the above-mentioned information (3) may be, for example, information indicating the ordinal number of a PDCCH monitoring occasion for paging among PDCCH monitoring occasions for paging within a PO. As another example, the above-mentioned information (3) may be information indicating the ordinal number of a PO or a PDCCH monitoring occasion for paging among POs or PDCCH monitoring occasions for paging within a DRX cycle. The above-mentioned information (3) enables, for example, a UE to quickly grasp paging timing to which a predetermined timing priority is assigned.

[0157] As another example, the information (3) above may include parameters used to determine paging timing. The parameters may include part or all of the broadcast information from the base station of the network, for example, PCCH configuration information (PCCH-Config) disclosed in Non-Patent Document 22 (TS38.331). This makes it possible to reduce the amount of processing by the base station when notifying the UE.

[0158] The information in (4) above may be, for example, information indicating a pattern in which, in the case of two-stage timing priority, high timing priority and low timing priority are alternately assigned to each PF. Alternatively, the information in (4) above may be information indicating a pattern in which high timing priority is assigned twice in succession, followed by low timing priority is assigned twice in succession, and this pattern is repeated. The PF in the above may be a PO or a PDCCH monitoring occasion for paging. The information in (4) above, for example, enables a UE to quickly grasp the assignment of timing priority.

[0159] The information (5) above may be, for example, information about the cycle of the pattern (4) above. The information (5) above may be provided at a cycle different from the DRX cycle. For example, the cycle of the timing priority allocation pattern may span multiple DRX cycles. This makes it possible to avoid a situation where, for example, paging at a predetermined paging timing in a certain network has a lower timing priority than paging timing in another network and cannot always be received.

[0160] The information (6) above may be information about a paging timing to which a high timing priority is assigned when, for example, high and low timing priorities are alternately assigned to each PF. The information (6) above may also include information about the timing priority of a reference paging timing. This makes it possible to prevent, for example, discrepancies in the understanding of timing priority assignment between a base station and a UE. As a result, it is possible to improve the stability of operation in a communication system.

[0161] The information in (7) above may be, for example, information indicating which PF, PO, or PDCCH monitoring occasion for paging is assigned within a DRX cycle for each timing priority. The DRX cycle may be a PF or a PO. The information in (7) above enables, for example, a UE to quickly ascertain the paging timing to which a predetermined timing priority is assigned.

[0162] As another example, the information in (7) above may include parameters used to determine paging timing for each timing priority. The parameters may include part or all of the broadcast information from the base station of the network, for example, PCCH configuration information (PCCH-Config) disclosed in Non-Patent Document 22 (TS38.331). This, for example, makes it possible to improve the flexibility of paging timing configuration in a communication system.

[0163] The correspondence between timing priority and type priority may be determined by a standard. For example, the message identifier disclosed in Section 9.4.1.2.2 of Non-Patent Document 21 (TS23.041 V16.2.0) may be used to determine the correspondence. This may reduce the complexity of the design of a communication system, for example.

[0164] As another example, the core NW may determine the correspondence between the timing priority and the type priority. This allows, for example, improved flexibility in the correspondence between the two priorities. The core NW may be, for example, an AMF or a PCF. The core NW may notify the base station of information regarding the determined correspondence. The base station may notify the UE of the information regarding the correspondence individually or may broadcast it. As another example, the core NW may notify the UE of the information directly. For example, the AMF may notify the UE of the information using NAS signaling.

[0165] As another example, the base station may determine the correspondence between the timing priority and the type priority. This allows, for example, further improvement in flexibility regarding the correspondence between the two priorities. The base station may notify or broadcast information about the correspondence to the UE individually.

[0166] As another example of the association between timing priorities and type priorities, the above combinations may be used. For example, the standard may provide a predetermined range for the type priorities associated with each timing priority, and the core network may determine the association using the predetermined range in the standard. This allows the association to be flexibly performed in a communication system, for example.

[0167] The assignment of type priorities may be determined by a standard. For example, the message identifier disclosed in Section 9.4.1.2.2 of Non-Patent Document 21 (TS23.041 V16.2.0) may be used for the assignment. This makes it possible to avoid complexity in the design of a communication system, for example.

[0168] As another example, the core NW may determine the allocation of type priorities. This enables, for example, improved flexibility in the allocation of type priorities. The core NW may be, for example, an AMF or a PCF. The core NW may notify the base station of information regarding the determined allocation. The base station may notify the UE of the information regarding the allocation individually or may broadcast it. As another example of notifying the UE of the information regarding the allocation, the core NW may notify the UE directly. For example, the AMF may notify the UE of the information using NAS signaling.

[0169] As another example of the assignment of type priorities, the base station may determine the assignment. This allows, for example, further improvement in the flexibility of the assignment of type priorities. The base station may individually notify or broadcast information about the assignment to the UE.

[0170] As another example of the assignment of type priorities, the above combinations may be used. For example, the type priorities assigned to each type of paging may have a predetermined range in the standard, and the core network may determine the type priorities using the predetermined range in the standard. This allows, for example, flexible assignment of type priorities to paging in a communication system.

[0171] The UE receives a paging message with a high timing priority among the paging messages of multiple networks with timing conflicts. The UE may perform this operation when it has a single receiver. The UE may switch the receiving network when receiving a paging message with a high timing priority. This allows the UE to receive a paging message with a high priority among the multiple paging messages with timing conflicts, for example.

[0172] The UE may choose not to receive any paging other than the paging with the highest timing priority among the paging messages from multiple networks whose timings partially collide. This makes it possible to reduce the power consumption of the UE, for example.

[0173] The UE may notify the base station of information about a paging that it does not receive (hereinafter, sometimes referred to as a non-received paging). The information may include information about a paging from another network (hereinafter, sometimes referred to as a colliding network) that collides with the non-received paging (hereinafter, sometimes referred to as a colliding network paging).

[0174] As examples of information regarding non-received paging, the following items (1) to (15) are disclosed.

[0175] (1) Information regarding the timing of unreceived pages.

[0176] (2) Information regarding the timing priority of unreceived pages.

[0177] (3) Information about the identifier of the collision network.

[0178] (4) Information about the timing of collision NW paging.

[0179] (5) Information on numerology in the collision network.

[0180] (6) Information about frame timing in the collision network.

[0181] (7) Information used to derive the timing of collision network paging.

[0182] (8) Information about the beam used for communication with the collision network.

[0183] (9) Information about the synchronization signal of the collision network.

[0184] (10) Information about the radio access technology (RAT) of the collision network.

[0185] (11) Information regarding timing priority of paging in a collision network.

[0186] (12) Information regarding the operation of multiple SIMs in the user equipment.

[0187] (13) Information indicating a request for a setting change regarding non-received paging.

[0188] (14) Information regarding type priority.

[0189] (15) A combination of (1) to (14) above.

[0190] The information (1) above may be information indicating which PF, PO, or PDCCH monitoring occasion for paging within a DRX cycle is the non-received paging. The information (1) above may be information using the frame number, subframe number, slot number, or symbol number of the non-received paging. This allows, for example, the UE to quickly notify the base station.

[0191] The information in (2) above may be the same as the information in (2) disclosed as information on timing priority assignment that the core network and / or base station notifies or broadcasts to the UE. The information in (2) above makes it possible to reduce the amount of processing required for the base station to reassign timing priorities, for example.

[0192] The information (3) above may be, for example, the PLMN-ID of the other network, or may include the NPN-ID disclosed in Non-Patent Document 25 (TR23.734), or may include the CAG-ID. This allows, for example, the base station to know the network for which paging collisions should be avoided, and as a result, the complexity of the avoidance process can be avoided.

[0193] As another example of the information (3) above, an identifier that uniquely identifies the UE may be used. The identifier may be, for example, a 5G Globally Unique Temporary Identifier (5G-GUTI). The base station may extract the PLMN-ID of the other network from the 5G-GUTI. This allows the base station to simultaneously acquire the identifier of the other network and the identifier of the UE, for example. As a result, the base station can acquire information used to derive paging timing in the other network with less signaling.

[0194] The information (4) above may be, for example, a paging frame (PF) or a paging occasion (PO) in another network, a PDCCH monitoring occasion used for paging reception, or a combination of two or more of the above. This makes it possible to reduce the amount of processing required for avoiding paging collisions by the base station, for example.

[0195] As another example, the information (4) above may include information about the time of paging timing in another network. The information about time may include, for example, the time of the start point of the paging timing, the time of the end point of the paging timing, information about the duration of the paging timing, or a combination of the above information. The paging timing may be a paging frame (PF) or a paging occasion (PO) in another network, a PDCCH monitoring occasion used for paging reception, or a combination of a plurality of the above information. This makes it possible to reduce the amount of processing required for paging collision avoidance by a base station, for example.

[0196] The information in (5) above may be, for example, the subcarrier spacing, slot length, or symbol length used by the UE when receiving paging from another network. The information in (5) above may be the parameter μ disclosed in Section 4.2 of Non-Patent Document 13 (TS38.211). This may improve the reliability of paging collision avoidance by the base station, for example.

[0197] The information in (6) above may be, for example, the difference in frame timing between the notification destination base station and a base station of another network given in SFN units, subframe units, slot units, symbol units, or the smallest unit in the communication system (for example, Ts units), or a combination of these. The slot in the above may be a slot in the notification destination base station or a slot in another network. This makes it possible to reduce the amount of processing required by the base station to avoid paging collisions, for example.

[0198] As another example, the information in (6) above may be a predetermined point in time in the other network, for example, the time at a boundary of a predetermined SFN. The boundary may be the beginning or the end of the SFN. As another example, the information in (6) above may be the time at a predetermined subframe boundary, the time at a predetermined slot boundary, or the time at a predetermined symbol boundary. The UE may obtain the information by performing a cell search for the other network, or may obtain the information from broadcast information from the other network. This may, for example, reduce the amount of processing required for the UE to make the notification.

[0199] The information in (7) above may include, for example, an identifier of the UE in another network, or may include parameters used to determine paging timing in the other network. The parameters may include part or all of the broadcast information from the base station of the network, for example, PCCH configuration information (PCCH-Config) disclosed in Non-Patent Document 22 (TS38.331). This may reduce the amount of processing required for the notification from the UE, for example.

[0200] The identifier for the information (7) may be, for example, the UE_ID disclosed in section 7.1 of Non-Patent Document 26 (TS38.304), or the 5G-S-TMSI (5G S-Temporary Mobile Subscription Identifier), 5G-TMSI (5G Temporary Mobile Subscription Identifier), or 5G-GUTI disclosed in Non-Patent Document 27 (TS23.501).

[0201] The above-mentioned parameters relating to the information (7) may include the UE's DRX (Discontinuous Reception) period (T), the total number of paging frames in the period (N), the number of paging occasions in the PF (Ns), the offset (PF_offset) used in determining the PF, or the first PDCCH monitoring occasion in the PO (first-PDCCH-MonitoringOccasionOfPO), as disclosed in Non-Patent Document 26 (TS38.304).

[0202] The information in (8) above may be information about a beam that the UE uses to receive from the notified base station. The beam may be information about a beam that the UE uses to receive SS blocks from the base station. The beam may be information about a beam that the UE uses to receive broadcast information from the base station, for example, SIB1 or RMSI (Remaining Minimum System Information). The base station may use the information in (8) above to change the paging timing of the beam in which the UE is located. The base station may also change the broadcast information of the beam. This allows the base station to flexibly change the paging timing, for example.

[0203] The information in (9) above may be, for example, information about the period of an SS burst, or the duration of SS block transmission in one period of an SS burst. The base station may use the information in (9) above to set paging timing, for example, by avoiding multiple SS burst periods transmitted from a base station in another network, or by avoiding the duration of SS block transmission. The UE may use the information to receive a synchronization signal from a base station in another network. The UE may receive paging after receiving the synchronization signal. This may, for example, prevent timing deviations in the UE's paging reception.

[0204] The information in (10) above may be, for example, information indicating that the base station of the other network is an NR base station, or information indicating that the base station is an LTE base station. The base station may use this information to change the paging timing. For example, if the base station of the other network is an LTE base station and the paging timing in the LTE base station is fixed, the base station may change the cycle of the paging timing. This may reduce the possibility of failing to avoid paging collisions in the communication system, for example.

[0205] The information in (11) above may be, for example, a timing priority value of a paging that collides with a non-received paging, or information about timing priorities assigned to paging from base stations in other networks. The base station may use the information in (11) above to change the timing priority of the non-received paging, or may change the timing priority assigned to paging by the base station. This may reduce the possibility of failing to avoid paging collisions in a communication system, for example.

[0206] The information in (12) above may be, for example, information indicating whether the UE is a multi-SIM UE, or information regarding operation using multiple SIMs. The information regarding operation using multiple SIMs may include, for example, the number of transmitters and / or receivers in the UE, the number of networks to which the UE can connect, or the number of RRCs that the UE can hold. The information regarding operation using multiple SIMs may be information regarding a combination of RRC states in the UE, for example, information indicating whether the UE can be RRC_CONNECTED simultaneously with multiple base stations among the base stations of multiple networks. The UE may notify the base station of this information, for example, by including it in UE capabilities. The base station may use this information for data transmission and reception with the UE. This may, for example, improve the efficiency of the communication system.

[0207] The information in (13) above may be, for example, information requesting a change in paging timing in the base station, information requesting a change in allocation of paging timing priority in the base station, information requesting a change in the correspondence relationship between paging timing priority and type priority, or a combination of two or more of the above. The base station may use the information to change the paging timing, change the allocation of paging timing priority, or change the allocation of paging timing priority and type priority. This may, for example, reduce the amount of processing required for changing the settings in the base station.

[0208] The information in (14) above may be, for example, information indicating the correspondence between paging timing priority and type priority in the collision network, or similar information in the own network. The base station may use the information in (14) above to change the timing of paging, change the allocation of paging timing priority, or change the allocation of paging timing priority and type priority. This allows, for example, the base station to reduce the amount of processing required to change the settings.

[0209] The UE may notify the base station of information regarding the missed paging using RRC signaling. For example, the UE may use an RRC setup request (RRCSetupRequest) for the notification. The UE may use the RRC setup request signaling for the notification when the RRC state related to the connection with the base station is RRC_IDLE. This allows, for example, the UE to quickly perform the notification to the base station. As another example, the UE may use an RRC setup complete (RRCSetupComplete) for the notification. The UE may use the RRC setup complete signaling for the notification when the RRC state related to the connection with the base station transitions from RRC_IDLE to RRC_CONNECTED. This allows, for example, the UE to notify the base station including a lot of information.

[0210] As another example, the UE may use an RRC resumption request (RRCResumeRequest) for the notification. When the RRC state related to the connection with the base station is RRC_INACTIVE, the UE may use signaling of an RRC resumption request for the notification. This allows, for example, the UE to quickly execute the notification to the base station. As another example, the UE may use an RRC resumption complete (RRCResumeComplete) for the notification. When the RRC state related to the connection with the base station transitions from RRC_INACTIVE to RRC_CONNECTED, the UE may use signaling of an RRC resumption complete for the notification. This allows, for example, the UE to notify the base station including a lot of information.

[0211] As another example, the UE may use RRCReconfigurationComplete for the notification, which allows the UE to include a lot of information in the notification to the base station.

[0212] As another example, new RRC signaling may be provided. For example, signaling called an RRC reconfiguration request (RRCReconfigurationRequest) may be provided and used, or signaling called a paging configuration information notification (PagingConfigurationInformationNotification) may be provided and used.

[0213] As another example of notification from the UE to the base station, MAC signaling may be used, which may allow, for example, the UE to quickly notify the base station of a paging collision. As another example, L1 / L2 signaling may be used, which may allow, for example, the UE to more quickly notify the base station of a paging collision.

[0214] The base station may use information regarding non-received paging obtained from the UE to change the allocation of timing priorities, change the timing of paging, change the correspondence between timing priorities and type priorities, or change the allocation of type priorities to each paging type.

[0215] The base station may change the paging timing using the notification from the UE. The base station may also change a parameter used to determine the paging timing. The parameter may be, for example, PCCH configuration information (PCCH-Config) disclosed in Non-Patent Document 22 (TS38.331).

[0216] The base station may uniformly assign timing priorities, determine the correspondence between timing priorities and type priorities, assign type priorities to each paging type, and / or change the paging timing to UEs served by the cell. The base station may broadcast information about the changes to UEs served by the cell. The UEs served by the cell may use the information about the changes to update settings related to the timing priorities of paging, settings related to the paging timing, settings related to the correspondence between timing priorities and type priorities, or settings related to the assignment of type priorities to each paging type.

[0217] For example, the base station may broadcast the changed parameters to the UEs under its control. For example, the base station may broadcast the changed parameters by including them in SIB1. The UEs may use the broadcast to change the timing at which they receive paging (hereinafter, may be referred to as paging reception timing).

[0218] As another example, the base station may change the parameter for each beam. The broadcast information from the base station may be different for each beam. This, for example, can improve the flexibility of parameter setting in the communication system.

[0219] As another example, the base station may individually assign timing priorities, determine the correspondence between timing priorities and type priorities, assign type priorities to each paging type, and / or change the paging timing for each UE. The base station may individually notify the UEs served by the cell of information related to the changes. For example, RRC dedicated signaling may be used for the notification. The UE may use the information related to the changes to update a setting related to the timing priority of paging, a setting related to the timing of paging, a setting related to the correspondence between timing priorities and type priorities, or a setting related to the assignment of type priorities to each paging type, using the information related to the changes.

[0220] For example, the base station may change parameters used to determine paging timing for each UE individually. The base station may notify each UE of the changed parameters. The base station may include the changed parameters in RRC signaling, for example, RRC reconfiguration, and notify each UE individually. The UE may change the paging reception timing using the individual notification. This makes it possible to avoid complex processing related to changing the paging timing in a communication system, for example.

[0221] As another example, the base station may set or change the parameter collectively for multiple UEs. For example, the base station may set and / or change the parameter collectively for multiple multi-SIM UEs. For example, the multiple multi-SIM UEs may be all multi-SIM UEs under the umbrella of the base station. For example, the multiple multi-SIM UEs may have the same or different network connection destinations other than the base station. The multiple multi-SIM UEs may be treated as a UE group. The base station sets and / or changes the parameter for the UE group.

[0222] The base station may collectively notify the plurality of UEs of the parameters that have been collectively set and / or changed for the plurality of UEs. For example, RRC signaling may be used for the notification. A specific UE-ID, for example, a multicast UE-ID, may be provided for the collective notification. The plurality of UEs may set and / or change the parameters using the collective notification. This may, for example, reduce the amount of signaling between the base station and the plurality of UEs.

[0223] The above-described collective notification from the base station to the plurality of UEs may be performed in other RRC signaling, which may further reduce the amount of signaling between the base station and the plurality of UEs, for example.

[0224] The UE may notify a base station of another NW of the changed parameters notified by the base station. The UE may include information about the UE's identifier in the notification to the base station of the other NW. The identifier may be an identifier assigned in the NW of the base station that changed the parameters. The base station of the other NW may or may not change the paging timing in the other NW using the parameters. This makes it possible, for example, to change the paging timing in the other NW while avoiding the notified parameters. As a result, it is possible to prevent paging collisions after changing the paging timing.

[0225] The base station may request the AMF to change the identifier of the UE. The base station may make the request, for example, when paging collision cannot be avoided by changing only the parameters used to determine the paging timing (for example, PCCH configuration information (PCCH-Config)). The base station may not make the request to the AMF when paging collision can occur by changing the parameters. This makes it possible to prevent unnecessary changes to the identifier, for example, when paging collision can be avoided by changing only the PCCH configuration information. The request may include one or more UE identifiers that are candidates for change. For example, signaling on the N2 interface may be used for the request. New signaling, for example, signaling of an N2 UE configuration update request, may be provided and used. 。UThe identifier of E may be, for example, the UE_ID disclosed in Section 7.1 of Non-Patent Document 26 (TS38.304), or may be a 5G-S-TMSI (5G S-Temporary Mobile Subscription Identifier), a 5G-TMSI (5G Temporary Mobile Subscription Identifier), or a 5G-GUTI disclosed in Non-Patent Document 27 (TS23.501). The AMF may change the identifier of the UE using the signaling.

[0226] The base station may notify the AMF of information used for paging collision avoidance. The base station may notify the information by including it in the request for the UE identifier. The information may include the above-mentioned information (1) to (15). The base station may convert the above-mentioned information (1) to (15) notified from the UE into signaling on the N2 interface and notify it. The information may further include information about the own network. The information about the own network may be the above-mentioned information (1) to (15) where another network is replaced with the own network. The AMF may change the UE identifier using the information about the own network. This makes it possible to prevent paging collisions in the changed UE identifier, for example.

[0227] The AMF may notify the UE of the changed identifier. For this notification, NAS signaling, for example, a CONFIGURATION UPDATE COMMAND disclosed in Non-Patent Document 32 (TS24.501), may be used. The identifier may be, for example, a 5G S-Temporary Mobile Subscription Identifier (5G-S-TMSI) disclosed in Non-Patent Document 27 (TS23.501). The UE may use this notification to update its own UE-ID.

[0228] The UE may notify the AMF of the completion of updating its own UE identifier. For this notification, NAS signaling, for example, CONFIGURATION UPDATE COMPLETE disclosed in Non-Patent Document 32 (TS24.501), may be used.

[0229] The AMF may notify the base station of the changed identifier. This notification may be made using signaling on the N2 interface. The base station may use this notification to change the paging timing of the UE. For example, the base station may use the changed identifier of the UE to change parameters used to determine the paging timing. This may, for example, improve the flexibility of changing the paging timing in the UE. The notification of the changed parameters from the base station to the UE may be similar to that described above.

[0230] FIG. 15 is a diagram showing a first example of the allocation of timing priorities for paging from multiple NWs and paging received by a UE. In the example shown in FIG. 15, timing priorities are assigned in two stages: high and low. In the example shown in FIG. 15, arrow 1500 indicates the DRX cycle in NW#1 of the UE, and arrow 1501 indicates the DRX cycle in NW#2 of the UE. In the example shown in FIG. 15, areas 1505 to 1507 indicate paging timings for NW#1, and areas 1510 to 1512 indicate paging timings for NW#2. In the example shown in FIG. 15, areas 1505, 1507, and 1511 indicated by white squares indicate paging timings assigned with low timing priorities, and areas 1506, 1510, and 1512 indicated by black squares indicate paging timings assigned with high timing priorities.

[0231] 15, the paging timings indicated by areas 1505 and 1510 overlap each other. In this case, the UE receives a paging from NW#2, which is assigned a higher timing priority, in area 1515. Similarly, the UE receives a paging from NW#1 in area 1516 and a paging from NW#2 in area 1517.

[0232] As another example of timing priority assignment, paging timing may be set for each timing priority. For example, each parameter of the PCCH configuration information (PCCH-Config) disclosed in Non-Patent Document 22 may be determined for each timing priority. A UE may have multiple paging timings in one paging cycle. When the timing of paging with a certain timing priority overlaps with the timing of paging with another timing priority in one UE, the paging with the higher timing priority may be given priority.

[0233] Figure 16 is a diagram showing a second example of the allocation of timing priorities for paging from multiple NWs and paging received by a UE. In the example shown in Figure 16, timing priorities are assigned in two stages: high and low. In Figure 16, paging timings with high and low timing priorities are respectively set for the UE from both NW#1 and NW#2. In Figure 16, elements common to Figure 15 are assigned the same element numbers, and common explanations will be omitted.

[0234] 16, paging timings with high timing priority assigned from NW#1 are set as areas 1606, 1608, and 1610, and paging timings with low timing priority assigned from NW#1 are set as areas 1605, 1607, and 1609. In the example shown in FIG. 16, paging timings with high timing priority assigned from NW#2 are set as areas 1615, 1617, and 1619, and paging timings with low timing priority assigned from NW#2 are set as areas 1616, 1618, and 1620.

[0235] In the example shown in FIG. 16 , the paging timings indicated by regions 1605 and 1615 overlap with each other. In this case, the UE receives a paging from NW #2, which is assigned a high timing priority, in region 1625. Since neither of the paging timings indicated by regions 1606 and 1616 overlaps with other paging timings, the UE receives a paging from NW #1 in region 1626 and a paging from NW #2 in region 1627. Similarly, the UE receives a paging from NW #2, which is assigned a high timing priority, in region 1628, a paging from NW #1 in region 1629, and a paging from NW #2 in region 1630. Similarly, the UE receives a paging from NW #2, which is assigned a high timing priority, in region 1631, a paging from NW #1 in region 1632, and a paging from NW #2 in region 1633.

[0236] The UE may associate the timing priority assigned in a certain network with the timing priority assigned in another network. This association may be performed, for example, when the number of stages of timing priority in a certain network is different from the number of stages of timing priority in another network. This allows the UE to compare the timing priority between multiple networks, even when the number of stages of timing priority differs between the multiple networks.

[0237] The method of association may be determined by a standard. The association may be performed, for example, from a timing priority with a small number of stages to a timing priority with a large number of stages. For example, in the case of two or three stages, high and low in the two-stage timing priority may be associated with high and low in the three-stage timing priority, respectively. This, for example, makes it possible to avoid complexity in the association.

[0238] As another example, the correspondence may be performed from a timing priority with a larger number of stages to a timing priority with a smaller number of stages. For example, when there are two or three stages, high, medium, and low in the three-stage timing priority may be respectively associated with high, high, and low in the two-stage timing priority. This, for example, makes it possible to improve the flexibility of the correspondence.

[0239] Another solution will be disclosed. Transmittable paging types are assigned for each timing priority. For example, when two timing priorities are provided, all types of paging may be transmitted with a high timing priority, and all types of paging except emergency communications may be transmitted with a low timing priority. As another example, when three timing priorities are provided, high, medium, and low, all types of paging may be transmitted with a high timing priority, all types of paging except emergency communications may be transmitted with a medium timing priority, and all types of paging except emergency communications, voice calls, and SI updates may be transmitted with a low timing priority. The method disclosed in the first embodiment may be used to assign timing priorities. The operation of the UE may be the same as the operation disclosed in the first embodiment. This, for example, eliminates the need for type priority assignment, and as a result, the amount of processing in the network device of the communication system can be reduced.

[0240] As another example, all paging types may be transmitted regardless of timing priority. This allows prompt reception of a paging message with a predetermined timing priority, for example, in a case where a paging message with a predetermined timing priority cannot be received due to a timing collision with a paging message with a higher timing priority from another network.

[0241] Another solution will be disclosed. A timing priority for transmission may be set for each paging type. In a case where two timing priority levels are provided, emergency communications may be transmitted only by paging with a high timing priority, while other types of paging may be transmitted by paging with both high and low timing priorities. As another example, in a case where three timing priority levels, high, medium, and low, are provided, emergency communications may be transmitted only by paging with a high timing priority, while voice calls and SI updates may be transmitted by paging with a high or medium timing priority, while other types of paging may be transmitted by paging with any of high, medium, and low timing priorities. The method disclosed in the first embodiment may be used to assign timing priorities. The operation of the UE may be the same as that disclosed in the first embodiment. This, for example, eliminates the need for type priority assignment, thereby reducing the amount of processing in the network device of the communication system.

[0242] As another example, all types of paging may be transmitted at all timing priorities, which allows prompt reception of a paging of a given type, for example, when a paging of a given timing priority cannot be received due to a timing conflict with a paging of a higher timing priority from another network.

[0243] The method disclosed in the first embodiment may be used when connections to multiple networks are active, for example, when the RRC state between the UE and base stations of the multiple networks is RRC_CONNECTED. The method disclosed in the first embodiment may be used when only connections to one network are active and connections to other networks are inactive, for example, when the RRC state between the UE and base stations of one network is RRC_CONNECTED and the RRC state between the UE and base stations of the other networks is RRC_INACTIVE or RRC_IDLE. The method disclosed in the first embodiment may be used when connections to multiple networks are inactive, for example, when the RRC state between the UE and base stations of the multiple networks is RRC_INACTIVE or RRC_IDLE. The UE may switch the destination network upon receiving paging. As a result, the UE may notify the base station of the source network of the connection switching information. The base station of the source network of the connection switching may use the information to stop scheduling for the UE. This enables, for example, efficient use of radio resources in the base station of the source network.

[0244] According to the first embodiment, it is possible to reduce the possibility that the UE will not receive the paging for the emergency communication due to a collision between the timing of the paging for the emergency communication and the timing of the paging for another network.

[0245] Variation 1 of Embodiment 1 In the first embodiment, a method is disclosed in which a UE gives priority to receiving a paging message with a high timing priority. In the present first modification, a method is disclosed regarding a receiving operation of a UE when timings of paging messages with the same timing priority collide.

[0246] The UE may receive paging from a base station with good communication quality, which may improve the reliability of paging reception, for example.

[0247] To determine communication quality, the UE may use a synchronization signal transmitted from the base station, a CSI-RS, a PDCCH, or a DM-RS, which may be a DM-RS of the PDCCH, a DM-RS of the PDSCH, or a DM-RS of the PBCH.

[0248] As another example, the UE may preferentially receive paging from a base station with fewer paging timings. The UE may use the DRX cycle, the number of PFs in the DRX cycle, the number of POs in the PF, or the number of PDCCH monitoring occasions in the PO to determine the base station with fewer paging timings. A combination of the above methods may also be used. As another example, the UE may preferentially receive paging from a base station with a longer time until the next paging timing. This, for example, makes it possible to reduce latency in paging reception.

[0249] As another example, the UE may receive a paging from a network different from the network from which the paging was previously received. For example, when paging with the same timing priority conflicts, the UE may switch the network from which the paging is received in order. That is, the network from which the UE receives the paging may be determined using a round robin. The above method may be used, for example, when paging from multiple networks conflicts at the same cycle. This makes it possible to prevent, for example, a situation in which paging from a specific network cannot be received for a long time in the above case.

[0250] As another example, the UE may switch the network from which the paging is received based on the fact that a paging occurred at the paging timing at which the UE performed the reception operation. The switching may be performed, for example, by sequentially switching between multiple networks. The switching may be performed using, for example, the aforementioned round robin. This allows the UE to receive paging from multiple networks even when, for example, the timings at which paging is actually transmitted overlap with each other at the paging timings from multiple networks.

[0251] As another example, a UE may have parameters related to paging reception from multiple networks. The parameters may be set for each network to which the UE connects, for each paging timing from the same network, or a combination of both. The parameters may be incremented over time, for example. A predetermined value may be subtracted from the parameters or initialized when the UE receives a paging from the network. The parameter may be subtracted or initialized when the UE actually receives a paging from the network. The predetermined value to be subtracted may be a constant value, or may differ for each timing priority, or may differ for each type of paging actually received, or may differ between when the UE performs a reception operation and when the UE actually receives a paging. The UE may receive a paging from the network with the highest value of the parameter. When the parameter value is the same among multiple networks, it may be predetermined which network the UE receives a paging from. This allows, for example, improved flexibility in receiving paging from multiple networks at a UE.

[0252] As another example, a UE may have a timer related to paging reception from multiple networks. The timer may be provided for each network to which the UE is connected, or for each paging timing from the same network, or a combination of both. The timer may start, for example, when the UE registers with the network (e.g., when RM_REGISTERED is reached). The timer may stop or be initialized when the UE receives a paging from the network. The parameter may stop or be initialized when the UE actually receives a paging from the network. The UE may receive a paging from the network with the shortest remaining time on the timer, or may receive a paging from the network whose timer expired first. The initial value of the timer may be constant across multiple networks or may differ for each network. The initial value of the timer may be determined by a standard, or may be determined by a device of each network (e.g., AMF, PCF, UPF, SMF, or base station) and notified to the UE. This provides, for example, the same effects as those described above.

[0253] The UE may notify the base station of information related to the aforementioned parameters or information related to the aforementioned timer. The base station may use the information to determine whether to transmit paging at a predetermined paging timing, or may determine the type of paging at the predetermined paging timing. For example, the base station may use the fact that the value of a parameter for its own network is the second highest or lower among the networks to determine not to transmit paging at the paging timing. This may enable, for example, a reduction in power consumption in the communication system.

[0254] As another example, the UE may receive a paging message at a preceding paging timing. The UE may perform this operation, for example, when the timings of paging messages from multiple networks partially overlap. This allows the UE to receive the paging message promptly, for example.

[0255] As another example, the UE may make this determination using the type of network. The type of network may be, for example, a PLMN or a private network (or a non-public network). The UE may, for example, preferentially receive paging from a base station on the PLMN side. This allows the UE to, for example, quickly receive an emergency call from the PLMN. As another example, the UE may, for example, preferentially receive paging from a base station on the private network side. This allows the UE to, for example, quickly receive downlink data generated in the private network.

[0256] A primary network and a secondary network may be provided. A UE with multiple SIMs may configure a primary network or a secondary network. The UE may configure the primary network and / or the secondary network in the base station and / or AMF of the primary network or in the base station and / or AMF of the secondary network. This makes it possible to avoid complex processing for notifying information about paging collisions in the design of a communication system.

[0257] A person may configure a primary network and / or a secondary network for a UE. For example, the primary network and the secondary network may be configured according to a person's preference. This makes it possible to perform paging collision avoidance for the network that the person prefers. The configuration of the primary network and / or the secondary network may be stored in the UE in advance. The UE can use the configuration of the primary network and / or the secondary network at any time.

[0258] The UE may receive paging from the base station of the primary network, which may reduce the amount of processing in the UE, for example.

[0259] For each timing priority disclosed in the first embodiment, it may be determined which network a paging message is to be received with priority. For example, if two levels of timing priority are provided, a paging message from a base station on the PLMN side may be received with priority for a paging message with a high timing priority, and a paging message from a base station on the private network side may be received with priority for a paging message with a low timing priority. This allows, for example, a UE to quickly receive downlink data generated in a private network while quickly receiving an emergency call from a PLMN.

[0260] The UE may determine the network from which to receive paging with priority by a method different from the above, which allows, for example, flexible execution of paging reception operations in the UE.

[0261] The UE may notify a base station of which base station of a network it will prioritize receiving paging from. As another example, the UE may notify the base station that it will not receive paging from the base station. The base station to which the notification is sent may be a base station from which the UE will not receive paging. The base station may use the notification to change the timing priority assignment or change the paging timing. The base station may notify the UE of the changed timing priority assignment or the changed paging timing. The notification from the base station to the UE may be performed using, for example, the method disclosed in the first embodiment. This makes it possible to prevent, for example, paging received by the UE from being biased toward base stations of a specific network. As another example, the base station to which the notification is sent may be a base station from which the UE receives paging. The UE may notify the base station from which the UE receives paging that it will receive paging. The base station may use the notification to determine the paging assignment at each paging timing. This makes it possible, for example, to improve the efficiency of paging notification in a communication system.

[0262] The UE may transmit the notification to the base station after acquiring information about paging timing from the base station of each connected NW. Alternatively, the UE may transmit the notification to the base station after acquiring information about timing priority of paging timing from the base station of each connected NW. Alternatively, the UE may transmit the notification to the base station after acquiring both of the above information.

[0263] As another example, when the UE switches which base station of a network from which paging is to be preferentially received, for example, when the communication quality with the base station from which the UE does not receive exceeds the communication quality with the base station from which the UE receives, the UE may notify the base station. The communication quality may be, for example, the synchronization signal and / or the RSRP, RSRQ, SINR, or received power of the CSI-RS from the base station. In the above case, the UE may include the notification to the base station in a measurement report. This allows, for example, a base station whose communication quality has deteriorated to use the paging timing for communication with other UEs, thereby improving communication efficiency.

[0264] The information included in the information from the UE to the base station regarding which base station of which network a paging should be received with priority may be the same as, for example, the information (1) to (15) disclosed as examples of information regarding non-received paging in embodiment 1. The information may include information regarding collisions of the same timing priority.

[0265] The notification from the UE to the base station may include a request for changing the paging timing. The base station may use the request to change the paging timing. The change in the paging timing at the base station, the notification or broadcast of the paging timing change from the base station to the UE, and / or the operation at the UE may be the same as, for example, the method disclosed in the first embodiment.

[0266] As another example, the base station may determine which base station of a network the UE should prioritize in receiving paging from. The base station may make this decision using, for example, a measurement report from the UE, or may make this decision using the type of network (e.g., PLMN, private network), or may prioritize a base station on the primary network side.

[0267] The base station making the decision may be, for example, a base station on the primary network side. This makes it possible to avoid, for example, complexity of control in the communication system. As another example, the base station making the decision may be a base station having good communication quality with the UE. This makes it possible to improve, for example, the quality of control from the base station to the UE. As another example, the base station making the decision may be a base station whose RRC connection state with the UE is RRC_CONNECTED. This makes it possible, for example, to avoid complexity of control in the communication system.

[0268] The base station may notify the UE of which base station of the network to prioritize receiving paging from. The UE may use the notification to perform reception processing of paging messages that overlap with each other.

[0269] The notification from the base station to the UE may be performed using RRC signaling, for example, RRC connection reconfiguration signaling. This allows, for example, the base station to notify the UE of more information. As another example, the notification from the base station to the UE may be performed using MAC signaling. This allows, for example, the base station to notify the UE of the information more quickly. As another example, the notification from the base station to the UE may be performed using L1 / L2 signaling. This allows, for example, the base station to notify the UE of the information more quickly.

[0270] As another example, the core network may determine which base station of the network the UE will receive paging from with priority. The core network may be, for example, an AMF, an SMF, or a PCF. The core network device may make the determination using, for example, the type of network (e.g., PLMN, private network), or may prioritize the base station on the primary network side.

[0271] The core NW device making the decision may be, for example, a device on the primary NW side. This makes it possible to avoid, for example, control complexity in a communication system. As another example, the core NW device making the decision may be a core NW device of a NW in a base station where communication quality with the UE is good. This makes it possible to improve, for example, the quality of control from the base station to the UE. As another example, the core NW device making the decision may be a core NW device of a NW in a base station where the state of the RRC connection with the UE is RRC_CONNECTED. This makes it possible to avoid, for example, control complexity in a communication system. As another example, the core NW device making the decision may be a core NW device of a NW where the connection state with the UE is CM_CONNECTED. This makes it possible to avoid, for example, control complexity in a communication system.

[0272] The core network device may notify the UE of which base station of the network to prioritize receiving paging from. The UE may use the notification to perform reception processing of paging messages with overlapping timing.

[0273] The notification from the core NW device to the UE may be performed using NAS signaling. NWThe device can notify the UE of a lot of information. As another example, the notification from the core NW device to the UE may be performed via a base station. The notification from the base station to the UE may be performed using RRC signaling, for example, RRC connection reconfiguration signaling. This allows, for example, the core NW device to notify the UE of a lot of information. As another example, the notification from the base station to the UE may be performed using MAC signaling. This allows, for example, the base station to notify the UE of the information quickly. As another example, the notification from the base station to the UE may be performed using L1 / L2 signaling. This allows, for example, the base station to notify the UE of the information more quickly.

[0274] The method disclosed in this modification 1 may be applied to a case where timing priority is not set. This allows the UE to quickly determine from which network it will receive paging, even when timing priority is not set for paging, for example.

[0275] This modification 1 allows the base station and / or core network device to know from which network the UE will have priority in receiving paging, thereby preventing malfunctions in the communication system.

[0276] Variation 2 of Embodiment 1 A UE with multiple SIM cards transmits and receives data to and from multiple networks. For example, if the UE is connected to multiple PLMNs, the UE may receive emergency communications with the same content from multiple PLMNs. This can cause a problem of memory size pressure in the UE.

[0277] In this second modification, a method for solving the above-mentioned problem is disclosed.

[0278] The UE may delete pages of the same type. The UE may keep only the first page it receives. The UE may delete pages it receives later. The UE may, for example, delete data related to the later-received pages or may not receive the data.

[0279] The operation in the UE may be applied only to a predetermined type of paging. For example, the operation in the UE may be applied to emergency communications. The emergency communications may be, for example, a Public Warning System (PWS), an Earthquake and Tsunami Warning System (ETWS), a Commercial Mobile Alert System (CMAS), a European Public Warning System (EU-ALERT), or a Korean Public Alert System (KPAS). The emergency communications may be, for example, emergency communications for a private network as disclosed in the first embodiment. The emergency communications may also be other emergency communications. This makes it possible to prevent, for example, the UE from mistakenly deleting data with different contents as the same data.

[0280] The UE may determine whether or not there is a duplication using information about the paging type. The information may be, for example, information included in the paging or information included in data related to the paging. The information may be, for example, a message identifier (Message Identifier) ​​disclosed in Section 9.4.1.2.2 of Non-Patent Document 21 (TS23.041 V16.2.0).

[0281] Paging may include information about the caller. For example, paging for an emergency communication may include information about the caller of the emergency communication. The information about the caller may be uniquely assigned regardless of PLMN, or may be assigned by each PLMN. When each PLMN assigns information about the caller, each PLMN may notify the UE of the information about the assignment to the caller. The notification to the UE may be performed by, for example, the AMF. The UE may use the information about the caller to determine whether there is a duplication. This makes it possible to prevent, for example, erroneously detecting duplication of data from different callers.

[0282] The paging may include information about a serial number. The serial number may be unique within the source. The UE may use the information about the serial number to determine whether there is a duplicate. This may prevent, for example, erroneous detection of duplicate data from the same source.

[0283] The UE may determine that paging messages of a predetermined type received within a predetermined time interval are paging messages related to the same data. For example, if the UE receives emergency communication paging messages from base stations of multiple networks within a predetermined time interval, the UE may determine that the emergency communications have the same content. This allows the UE to determine that the emergency communications have the same content even if the UE receives emergency communications with the same content from multiple networks at different times.

[0284] The predetermined time difference may be specified in advance, may be determined by the core network and notified to the UE, or may be determined by the base station and notified to the UE.

[0285] The base station making the decision may be, for example, a base station on the primary NW side, as in Variant 1 of Embodiment 1. This makes it possible, for example, to avoid complexity of control in the communication system. As another example, the base station making the decision may be a base station having good communication quality with the UE. This makes it possible, for example, to improve the quality of control from the base station to the UE. As another example, the base station making the decision may be a base station whose RRC connection state with the UE is RRC_CONNECTED. This makes it possible, for example, to avoid complexity of control in the communication system.

[0286] As in the first modification of the first embodiment, the core network may be, for example, an AMF, an SMF, or a PCF. The core network device may make the decision using, for example, the type of network (e.g., PLMN, private network), or may prioritize the base station on the primary network side.

[0287] The core NW device making the decision may be, for example, a device on the primary NW side, as in the first modification of the first embodiment. This makes it possible, for example, to avoid complexity in control in the communication system. As another example, the core NW device making the decision may be a core NW device of a NW in a base station where communication quality with the UE is good. This makes it possible, for example, to improve the quality of control from the base station to the UE. As another example, the core NW device making the decision may be a core NW device of a NW in a base station where the state of the RRC connection with the UE is RRC_CONNECTED. This makes it possible, for example, to avoid complexity in control in the communication system. As another example, the core NW device making the decision may be a core NW device of a NW where the connection state with the UE is CM_CONNECTED. This makes it possible, for example, to avoid complexity in control in the communication system.

[0288] The predetermined time difference may be determined by multiple networks, for example, multiple core network devices. Alternatively, the predetermined time difference may be determined by multiple base stations. The predetermined time difference may differ among multiple networks or may differ among multiple base stations. The UE may use a shorter time among the times that differ among multiple networks and / or base stations. This makes it possible, for example, to prevent the UE from mistakenly deleting different data as the same data. As another example, the UE may use a longer time among the times that differ among multiple networks and / or base stations. This makes it possible, for example, to prevent the UE from mistakenly detecting the same data as different data, thereby reducing the amount of processing by the UE.

[0289] The predetermined time difference may be set for each paging type, which allows, for example, improved flexibility in the communication system.

[0290] This operation in the UE may be applied when the same PLMN is used. That is, this operation in the UE may not be applied when the UEs are connected to different PLMNs. This prevents the UE from erroneously detecting different paging types as the same paging type, for example, when different paging types are set for the same message identifier (see Non-Patent Document 21 (TS23.041 V16.2.0)) in each NW.

[0291] The operation in the UE may be applied in the private network, which enables the UE to detect duplicate emergency communications for the private network with the same content, thereby reducing the amount of processing in the UE.

[0292] As another example, the operation in the UE may be applied when the same private network is used. This prevents the UE from erroneously detecting different paging types as the same paging type when, for example, different paging types are set for the same message identifier (see Non-Patent Document 21 (TS23.041 V16.2.0)) in each network.

[0293] Information regarding the allocation of message identifiers (see Non-Patent Document 21 (TS23.041 V16.2.0)) to paging types in each network may be notified to the UE. For example, NAS signaling may be used for the notification. The UE may use the notification to detect paging with the same content. This allows the UE to detect paging of the same type even if, for example, different message identifiers are assigned to the same paging type in different networks.

[0294] This second modification makes it possible to avoid receiving duplicate paging messages, thereby reducing the amount of processing in the UE.

[0295] Embodiment 2 A multi-SIM UE may maintain RRC connections with base stations of multiple networks, and may transmit and receive data to and from each of the base stations of the multiple networks in a time-division manner.

[0296] The following problem occurs in the above-described operation. For example, when a UE switches its transmission / reception destination from a base station of the original network (hereinafter sometimes referred to as base station #1) to a base station of another network (hereinafter sometimes referred to as base station #2), and while transmitting / receiving to / from base station #2, the UE maintains the RRC state with base station #1 in RRC_CONNECTED, but is unable to receive signals from base station #1. In this case, if the UE detects loss of synchronization with base station #1 and, as a result, detects RLF with base station #1, the UE needs to reconnect to base station #1.

[0297] In the second embodiment, a method for solving the above-mentioned problem will be disclosed.

[0298] The UE stops the timers and / or counters (hereinafter, sometimes referred to as RLF timers) used for RLF detection between the UE and base station #1. The RLF timers in the UE may be stopped when the UE switches the transmission / reception destination from base station #1 to base station #2. The RLF timers may be, for example, T310, N310, or N311 disclosed in Non-Patent Document 22 (TS38.331), or a combination of two or more of the above.

[0299] The UE may notify base station #1 of a switch in transmission / reception destination, or may notify base station #1 of the stop of RLF timers for base station #1. Base station #1 may use this notification not to perform scheduling for the UE. This may improve communication efficiency at base station #1, for example.

[0300] The base station may have a timer. The timer may be, for example, a timer that manages the activity of the UE (hereinafter, may be referred to as an inactivity timer). For example, the timer may be a timer that runs while no transmission or reception is performed between the base station and the UE. The timer may be a timer that stops or is initialized when transmission or reception is performed between the base station and the UE. When the timer expires, the base station may instruct the UE to release the RRC connection or may instruct the UE to suspend the RRC connection.

[0301] Using the notification from the UE, base station #1 may stop the inactivity timer. This prevents the timer from progressing when, for example, the UE's connection destination is switched from base station #1 to base station #2. As a result, it is possible to prevent the base station from deciding to suspend the UE's RRC connection while the switch is in progress.

[0302] The RLF timers in the UE may be stopped before the notification to base station #1, after the notification, or simultaneously with the notification. For example, stopping the RLF timers before the notification can reduce memory usage in the UE when the UE switches between transmitting and receiving. Also, for example, stopping the RLF timers after the notification can reduce the amount of processing required when the UE notifies base station #1. Also, for example, stopping the RLF timers simultaneously with the notification can avoid complexity related to timer management in the UE.

[0303] The notification from the UE to the base station #1 may be made dynamically. For example, L1 / L2 signaling may be used for the notification. This enables rapid execution of transmission / reception switching, for example, when uplink data from the UE to the base station #2 is generated. As another example, MAC signaling may be used for the notification. This makes it possible to notify a large amount of information by uplink transmission with a high modulation order, and improve reliability by retransmission control.

[0304] As another example, the notification from the UE to base station #1 may be made semi-statically. For example, RRC signaling may be used for the notification. A new RRC signaling may be provided for the notification. This eliminates the need for the UE to make the notification each time the transmitting / receiving destination is switched. As a result, it is possible to reduce the amount of signaling between the UE and the base station.

[0305] As another example, the transmission / reception destination switch in the UE may be determined in advance by the base station and notified to the UE. The UE may use the notification to determine the destination base station. The base station that notifies the UE may be determined in advance, for example. For example, the information may be included in the SIM of the UE. This may, for example, reduce the amount of signaling between the UE and the base station.

[0306] The UE may establish downlink synchronization with base station #2. The UE may establish downlink synchronization using a synchronization signal (e.g., SS block) from base station #2, or may establish downlink synchronization using another signal, for example, CSI-RS from base station #2. The UE may establish downlink synchronization with base station #2 after, for example, stopping RLF timers for base station #1. This makes it possible to prevent, for example, the RLF timers for base station #1 from expiring while the UE is receiving a downlink signal from base station #2. As another example, the UE may establish downlink synchronization with base station #2 after notifying base station #1 of a switch in transmission / reception destination. This, for example, eliminates the need for scheduling from base station #1 to the UE while the UE is establishing downlink synchronization, thereby improving communication efficiency in base station #1.

[0307] As another example, the UE may hold information regarding frame timing at both base stations #1 and #2. For example, the UE may hold information regarding the frame offset between base station #1 and base station #2. The UE may acquire the above-mentioned information when establishing an RRC connection with each of base stations #1 and #2. The UE may update the above-mentioned information. The UE may perform the update at a predetermined interval or when some event occurs. When the UE holds the above-mentioned information, it may not perform downlink synchronization establishment with base station #2. This makes it possible, for example, to quickly switch between transmission and reception between base station #1 and base station #2.

[0308] The UE starts or restarts timers and / or counters (hereinafter, sometimes referred to as RLF timers) used for RLF detection between the UE and base station #2. The RLF timers in the UE may be started or restarted after the UE switches the transmission / reception destination from base station #1 to base station #2, for example, after the random access process between the UE and base station #2 is completed.

[0309] The random access may be, for example, a two-step random access consisting of a PRACH transmission from the UE to the base station and an RA response from the base station to the UE, or a four-step random access. The UE may start or restart RLF timers after receiving the RA response from the base station, or may start or restart RLF timers after receiving the fourth-step response from the base station. After completing the random access, the base station may start a timer for the UE, such as an inactivity timer, or may restart it without initializing it. This makes it possible to avoid, for example, complexity related to controlling the RLF timers in the UE and / or the inactivity timer in the base station.

[0310] The UE may not perform random access processing with base station #2. The UE may not perform the above-mentioned random access processing, for example, when it can maintain uplink synchronization with base station #2. The UE may maintain uplink synchronization with base station #2 when, for example, a predetermined time has not elapsed since transmission and reception between the UE and base station #2 stopped, when the UE's location is within a predetermined range, or when the UE's speed is within a predetermined range. This allows, for example, transmission and reception between the UE and base station #2 to be resumed quickly.

[0311] The UE may notify base station #2 that the transmission / reception destination has been switched to base station #2, or may notify the restart of RLF timers for base station #2. The notification from the UE to base station #2 may be performed, for example, when random access is not performed between the UE and base station #2. The notification may be performed using L1 / L2 signaling. This allows, for example, the UE to quickly notify base station #2 of the switch in transmission / reception destination. As another example, the notification may be performed using MAC signaling. This allows, for example, improved reliability through retransmission control. As another example, the notification may be performed using RRC signaling. This allows, for example, the UE to notify the base station of more information. The base station may use the notification to start an inactivity timer for the UE, or may restart it without initializing it. This allows, for example, to avoid complexity related to inactivity timer control in the base station.

[0312] When the RLF timers are restarted, they may be initialized. This avoids complexity in the UE design. Alternatively, the RLF timers may not be initialized, i.e., they may be restarted from their stopped values. This allows the UE to quickly detect RLF, and therefore quickly recover from RLF, for example, if an actual loss of synchronization occurs between the UE and base station #2.

[0313] 17 is a sequence diagram showing an example of the operation of stopping and restarting RLF timers when a UE switches between transmitting and receiving destinations. In FIG. 17, the UE is connected to base station #1 under NW #1 and base station #2 under NW #2.

[0314] In Step ST1703 shown in Fig. 17, the UE is in the RRC_CONNECTED state for the connection between gNB#1 and gNB#2. In Step ST1705, data is transmitted and received between the UE and gNB#1.

[0315] In step ST1707 shown in FIG. 17, data intended for gNB#2 is generated from the UE. In step ST1709, the UE notifies gNB#1 that it will switch the connection destination of its own UE to gNB#2. The notification in step ST1709 may be performed by L1 / L2 signaling, MAC signaling, or RRC signaling. Using the notification of step ST1709, gNB#1 stops scheduling for the UE. In step ST1711, the UE stops the RLF timers intended for gNB#1. The RLF timers may be, for example, T310, N310, or N311 disclosed in Non-Patent Document 22 (TS38.331), or a combination of two or more of the above.

[0316] In step ST1713 shown in Fig. 17, gNB#2 transmits an SS block to the UE. In step ST1715, the UE establishes downlink synchronization with gNB#2 by receiving the SS block in step ST1713.

[0317] In Step ST1717 shown in FIG. 17, a random access procedure is performed between the UE and gNB#2. The random access procedure in Step ST1717 may be a random access consisting of two steps: a PRACH transmission from the UE to gNB#2 and an RA response from gNB#2 to the UE. This enables, for example, quick completion of the random access procedure between the UE and gNB#2. In Step ST1719, the UE restarts the RLF timers for gNB#2. In this restart, the RLF timers for gNB#2 may be initialized. Step ST1719 may be performed triggered by the completion of Step ST1717. The RLF timers for gNB#2 may be the same as the RLF timers for gNB#1 that were stopped in Step ST1711. In Step ST1721, data is transmitted and received between the UE and gNB#2.

[0318] In FIG. 17, after completion of Step ST1721, the UE's connection destination is switched from gNB#2 to gNB#1. In Step ST1723, the UE notifies gNB#2 that it will switch its UE's connection destination to gNB#1. The same signaling as in Step ST1709 may be used for the notification in Step ST1723. In Step ST1731, the UE stops the RLF timers for gNB#2. In Step ST1733, gNB#1 transmits an SS block to the UE. In Step ST1735, the UE establishes downlink synchronization with gNB#1 by receiving the SS block in Step ST1733.

[0319] In Step ST1737 shown in FIG. 17, random access processing is performed between the UE and gNB#1. The random access processing in Step ST1737 may be the same processing as in Step ST1717. In Step ST1739, the UE restarts the RLF timers for gNB#1. In the restart, the RLF timers for gNB#1 may be initialized. In Step ST1741, data is transmitted and received between the UE and gNB#1.

[0320] 17 shows a case where the random access in steps ST1717 and ST1737 is configured in two steps, but a four-step random access process may also be used. When a four-step random access is used, the base station may reconfigure the RRC parameters for the UE. This makes it possible to improve the flexibility of the communication system, for example.

[0321] Another solution is disclosed. The UE may not stop the RLF timers related to base station #1. The UE may not perform RLF processing after the RLF timers between the UE and base station #1 expire. The RLF processing may be, for example, a transition to RRC_IDLE, the processing disclosed in section 5.3.10.3 of Non-Patent Document 22 (TS38.331), or a combination of both. This, for example, makes it possible to avoid complexity in controlling the RLF timers in the UE.

[0322] In the above case, after the UE destination is switched back to base station #1, the UE may initialize the timers related to base station #1. This makes it possible to prevent erroneous RLF detection when the UE destination is switched back to base station #1, for example.

[0323] Other solutions will be disclosed. When the transmission / reception destination is switched from base station #1 to base station #2, the UE may detect RLF with base station #1. Some of the RLF processing with base station #1 may not be performed. For example, the UE may not transition to RRC_IDLE. In the RRC re-establishment operation disclosed in Section 5.3.7 of Non-Patent Document 22 (TS38.331), radio bearer termination may not be performed. MAC reset may not be performed. SCells in the MCG (Master Cell Group) may not be released. spCellcConfig may not be released. DC may not be released. p-NR-FR1 may not be released. p-UE-FR1 may not be released. delayBudgetReportingConfig may not be released. T342 may not be stopped. overheatingAssistanceConfig may not be released. T345 may not be stopped.

[0324] The UE may perform cell selection. A timer (e.g., T311) related to cell selection disclosed in Non-Patent Document 22 (TS38.331) may be started. This may, for example, avoid the complexity of the cell selection process. As another example, the UE may not start T311. This may, for example, prevent the RRC_IDLE transition due to the expiration of T311.

[0325] The UE may maintain the RRC parameters. The maintenance operation in the UE may be applied, for example, when the UE selects the same cell as before the RLF detection. This may reduce the amount of processing required for re-establishing the RRC connection. As another example, the UE may release the RRC parameters. The release operation in the UE may be applied, for example, when the UE selects a cell different from the cell selected before the RLF detection. This may improve the flexibility of the communication system.

[0326] The method disclosed in the second embodiment may be applied to beam failure. For example, the number of beam failure instance indications and / or the timer and / or counter associated with the number of beam failure instance indications disclosed in Section 9.2.8 of Non-Patent Document 16 (TS38.300) may be stopped or restarted when the UE switches between transmitting and receiving. The timer and / or counter may be, for example, the beamFailureRecoveryTimer, beamFailureDetectionTimer, or BFI_COUNTER disclosed in Non-Patent Document 17 (TS38.321). This makes it possible to prevent erroneous detection of beam failure when the UE switches between transmitting and receiving.

[0327] In applying the method disclosed in the second embodiment, the switching of the transmission / reception destination may not be performed until a random access response is received. As another example, the switching of the transmission / reception destination may not be performed until message 4 in the random access process is received. The above-described operation may be applied, for example, when the UE transmits a PRACH to the base station. This makes it possible to prevent, for example, failure of the random access process.

[0328] In applying the method disclosed in the second embodiment, the connection (e.g., NAS connection) between the UE and the network of the base station before the transmission / reception switching may be maintained. This allows, for example, a quick reconnection to the network of the base station. As another example, the connection between the UE and the network may be released. This allows, for example, a reduction in memory usage in the UE.

[0329] The method disclosed in the second embodiment may be applied to beam management and / or beam measurement. For example, the UE may notify the base station of information indicating that a beam could not be measured by including the information in a measurement report to the base station. The notification of the information indicating that a beam could not be measured from the UE to the base station may be performed, for example, when the UE switches the transmission / reception destination to a base station of another network. The UE may include information regarding the reason for the measurement failure in the notification. The reason may be, for example, switching of the transmission / reception destination. The base station may use the information for beam control for the UE. This makes it possible to prevent, for example, the base station from erroneously determining that the quality of the beam used between the UE and the base station is poor.

[0330] The method disclosed in the second embodiment may be used in the random access process. For example, when the destination base station of the UE switches from gNB#1 to gNB#2, the collision resolution timer for gNB#1, for example, the ra-ContentionResolutionTimer disclosed in Non-Patent Document 17 (TS38.321), may be stopped. This makes it possible to prevent false detection of collision in the random access process after the destination base station switches, for example.

[0331] When the destination base station of the UE switches from gNB#1 to gNB#2, the collision resolution timer for gNB#1 may be started or restarted. The above-mentioned starting or restarting may be performed from an initial value. This makes it possible, for example, to avoid complexity in the management of the timer by the UE. As another example, the collision resolution timer may be restarted from the value after it was stopped. This makes it possible, for example, for the UE to quickly detect a random access collision.

[0332] In the second embodiment, a case has been disclosed in which the UE is connected to base station #1 and base station #2, but the number of base stations to which the UE is connected may be three or more. For example, the method disclosed in the second embodiment may be used to switch the transmission / reception destination from base station #1 to base station #3. Also, for example, the method disclosed in the second embodiment may be used to switch the transmission / reception destination from base station #3 to base station #4. This enables, for example, flexible switching of the transmission / reception destination base station in the UE.

[0333] The method disclosed in the second embodiment may be used in MAC processing. For example, when the destination base station of the UE switches from gNB#1 to gNB#2, a timer (for example, SCellDeactivationTimer disclosed in Non-Patent Document 17 (TS38.321)) that manages the operating state of the SCell for gNB#1 may be stopped. The timer may be restarted when the destination base station of the UE switches back to gNB#1. This makes it possible to prevent the timer from expiring after the destination base station of the UE switches from gNB#1 to gNB#2, for example. As a result, it is possible to reduce the amount of processing related to reactivation of the SCell in the UE.

[0334] The above-mentioned operation may be applied to a timer (e.g., bwp-InactivityTimer disclosed in Non-Patent Document 17 (TS38.321)) that manages the operation state of the BWP (BandWidth Part) for gNB#1. This, for example, as described above, makes it possible to reduce the amount of processing related to reactivation of the BWP in the UE.

[0335] The above operation may be applied to a timer that manages the activity of data conduction for gNB#1 (for example, the dataInactivitiTimer disclosed in Non-Patent Document 17 (TS38.321)). This may, for example, prevent the UE from transitioning to RRC_IDLE, as described above.

[0336] The method disclosed in the second embodiment may be used in the RLC process. For example, the above-described operation may be applied to a timer (for example, t-Reassembly disclosed in Non-Patent Document 29 (TS38.322)) used in the reassembly process of the RLC PDU for gNB#1. This makes it possible to reduce the number of status check processes (for example, RLC STATUS PDU transmission) in the RLC, as described above.

[0337] The method disclosed in the second embodiment may be used in PDCP processing. For example, the above-described operation may be applied to a timer (for example, the discardTimer disclosed in Non-Patent Document 30 (TS38.323)) used to manage the discarding of PDCP SDUs for gNB#1. This makes it possible to prevent the discarding of PDCP SDUs, for example, as described above. As a result, it becomes possible to prevent packet loss in the communication system.

[0338] The above-mentioned operation may be applied to a timer used for PDCP reordering control (for example, t-Reordering disclosed in Non-Patent Document 30 (TS38.323)). This makes it possible to prevent received data undergoing reordering from being transmitted to a higher layer, as described above. As a result, it is possible to reduce the reordering process in the higher layer.

[0339] According to the second embodiment, it is possible to prevent the expiration of RLF timers related to the connection with the base station of the original network while the multi-SIM UE is transmitting and receiving data to and from the base station of another network. As a result, it is not necessary to re-establish the RRC connection with the base station of the original network.

[0340] Embodiment 3 A survival time (see Non-Patent Document 23 (TR22.832 V17.1.0)) indicating the allowable time for communication interruption before the application layer is disconnected when communication interruption occurs may be used for QoS control in the NW.

[0341] However, no method for QoS control using survival time has been disclosed, which means that the network cannot control communications using survival time, and the network cannot perform communications that meet the requirements of the application layer.

[0342] In the third embodiment, a method for solving the above-mentioned problem will be disclosed.

[0343] A QoS parameter related to survival time is provided. The network side device may notify the UE of the QoS parameter related to survival time. The QoS parameter notified by the network side device to the UE may be a QoS parameter related to survival time in downlink communication. The UE may notify the network side device of the QoS parameter related to survival time. The QoS parameter notified by the UE to the network side device may be a QoS parameter related to survival time in uplink communication.

[0344] The following (1) to (16) are disclosed as examples of QoS parameters related to survival time.

[0345] (1) Survival time value.

[0346] (2) MTBF (Mean Time Between Failure).

[0347] (3) MTTR (Mean Time To Repair).

[0348] (4) MUT (Mean Up Time).

[0349] (5) MDT (Mean Down Time).

[0350] (6) Inherent availability.

[0351] (7) Operational Availability.

[0352] (8) Tolerable latency.

[0353] (9) Number of times latency can be exceeded.

[0354] (10) The number of consecutive latency exceedances allowed.

[0355] (11) Number of times communication failure is permitted.

[0356] (12) The number of consecutive unreachable communications allowed.

[0357] (13) Communication cycle.

[0358] (14) RLC layer retention amount.

[0359] (15) PDCP layer retention amount.

[0360] (16) A combination of (1) to (15) above.

[0361] Regarding the above (1), for example, the core network device, the base station, and / or the UE may use the survival time value itself for QoS control. For example, the survival time requirement may be added to the 5QI table described in Non-Patent Document 27 (TS23.501). This makes it possible to avoid the complexity of QoS control using the survival time.

[0362] The above-mentioned (2) may be a value calculated by treating the expiration of the survival time timer as a failure. The core network device, the base station, and / or the UE may use the above-mentioned value of (2) to set up a communication path between the base station and the UE. This makes it possible to avoid complexity in controlling the reliability of communication, for example.

[0363] The above-mentioned (3) may be, for example, the time from when the survival time requirement is not met to when the communication path is restored. The core network device, the base station, and / or the UE may use the value of the above-mentioned (3) to set up a communication path between the base station and the UE. This may provide, for example, the same effect as the above-mentioned (2).

[0364] The above (4) may be, for example, the average time that an application operates while satisfying the survival time requirement. The core network device, the base station, and / or the UE may use the value of the above (4) to set up a communication path between the base station and the UE. This may provide, for example, the same effect as the above (2).

[0365] The above (5) may be, for example, the average time an application stops without satisfying the survival time requirement. The core network device, the base station, and / or the UE may use the value of the above (5) to set up a communication path between the base station and the UE. This may provide, for example, the same effect as the above (2).

[0366] The above-mentioned (6) may be a parameter given as MTBF / (MTBF+MTTR) using the above-mentioned (2) and (3). The core network device, the base station, and / or the UE may use the value of the above-mentioned (6) to set up a communication path between the base station and the UE. This may provide the same effect as the above-mentioned (2), for example.

[0367] The above-mentioned (7) may be a parameter given as MUT / (MUT+MDT) using the above-mentioned (4) and (5), for example. The core network device, the base station, and / or the UE may use the value of the above-mentioned (7) to set up a communication path between the base station and the UE. This may provide the same effect as the above-mentioned (2), for example.

[0368] The information in (8) above may be, for example, the packet delay budget disclosed in Section 5.7.3.4 of Non-Patent Document 27 (TS23.501). The information in (8) above may be used when communication is performed periodically on a communication path, or may be used for non-periodic communication. The core network device, base station, and / or UE may use the value in (8) above to assign QoS to data to be transmitted or received, or to perform scheduling. This makes it possible to prevent adverse effects on applications due to excessive data latency on a communication path, for example.

[0369] The above-mentioned (9) may be used, for example, when communication is performed periodically on a communication path. The above-mentioned (9) may be, for example, a value derived using the survival time value and the tolerable latency, for example, the survival time value divided by the tolerable latency. The core network device, the base station, and / or the UE may use the value of the above-mentioned (9) to assign QoS to the data to be transmitted and received or to perform scheduling. This may provide, for example, the same effect as the above-mentioned (8).

[0370] The above-mentioned (10) may be used, for example, when communication is performed periodically. The above-mentioned (10) may be a value obtained in the same way as the above-mentioned (9). By using the above-mentioned (10), for example, in a communication system, it is possible to prevent erroneous detection of a case where latency exceedance occurs sporadically as a survival time exceedance.

[0371] The above (11) may be used, for example, when data is not discarded after a latency exceedance, which can prevent application shutdowns due to a latency exceedance in a communication system where the latency exceedance is not fatal.

[0372] The above-mentioned (12) may be used, for example, when data is not discarded after the latency is exceeded. By using the above-mentioned (12), for example, in a communication system, it is possible to prevent sporadic communication failures from being erroneously detected as an excess of the survival time.

[0373] The above (13) may be used, for example, when communication is performed periodically on a communication path. The core network device, the base station, and / or the UE may use the value of the above (13) to assign QoS to data to be transmitted or received, or may perform scheduling. This may provide, for example, the same effect as the above (8).

[0374] The above-mentioned (14) may be used, for example, when communication is performed periodically on a communication path. The above-mentioned (14) may be calculated, for example, using the value of survival time, the communication period, and the amount of data transmitted and received in one period. The above-mentioned (14) may be the amount of data held up in an RLC entity of a receiving device. This makes it possible, for example, to quickly reflect the reception status of a receiving device in QoS control. As another example, the value of the above-mentioned (14) may be the amount of data held up in an RLC entity of a transmitting device. This makes it possible, for example, to reflect only data whose delivery has been confirmed in QoS control, thereby enabling QoS control that is closer to the control status of an upper layer.

[0375] The above-mentioned (15) may be calculated using, for example, the survival time value, the communication cycle, and the amount of data transmitted and received in one cycle. The above-mentioned (15) may be the amount of data held up in the PDCP entity of the receiving device, as in the above-mentioned (14), or the amount of data held up in the PDCP entity of the transmitting device. By using the amount of data held up in the PDCP layer, for example, QoS control closer to the control status of the upper layer becomes possible.

[0376] Regarding the above (16), for example, the survival time may be used as the product of the allowable number of consecutive communication failures and the communication cycle.

[0377] The above (1) to (16) may be combined with existing QoS parameters, such as those disclosed in Section 5.7.2 of Non-Patent Document 27 (TS23.501). This allows for flexible QoS control.

[0378] Information about the survival time (e.g., the value of the survival time) may be notified from the AF. The notification may, for example, request the 5G system to meet the survival time. The notification may include information about the communication that must meet the survival time. The information about the communication that must meet the survival time may include, for example, information about the sending and receiving hosts (e.g., source IP address, destination IP address, source port number, and / or destination port number), or information about the transmission data (e.g., information indicating whether it is TCP or UDP).

[0379] The AF may notify the core network device of the information. The core network device may be, for example, a PCF, a UDM, an SMF, an AMF, a UPF, or an NWDAF (Network Data Analytics Function; see Non-Patent Document 31 (TS23.288)). The core network device may use the information to perform QoS control in the communication system. For example, the core network device may use the information to convert the QoS parameters (2) to (16) disclosed as examples of QoS parameters related to survival time, convert the QoS parameters to existing QoS parameters, or convert the QoS parameters to both of the above. As an example of the conversion, the value of the survival time and the allowable latency may be used to derive the allowable number of consecutive latency exceedances, for example, by dividing the survival time value by the allowable latency value.

[0380] For example, the NWDAF may use the information from the AF to convert the information into QoS parameters used in the communication system. The NWDAF may use information acquired by itself (e.g., input data disclosed in Section 6.4.2 of Non-Patent Document 31 (TS23.288)) to convert the information into QoS parameters. Information on the occlusion frequency disclosed in Variant 3 of Embodiment 3 may also be used. This enables, for example, QoS control that reflects the status of the communication system and reduces the amount of signaling required to derive the QoS parameters.

[0381] As another example, the AF may notify the core network device of (1) to (16) disclosed as examples of QoS parameters related to survival time. As described above, the core network device may be a PCF, a UDM, an SMF, an AMF, a UPF, or an NWDAF (Network Data Analytics Function; see Non-Patent Document 31 (TS23.288)). The core network device may use the information to perform QoS control in the communication system. This, for example, makes it possible to reduce the amount of processing for QoS control in the core network device.

[0382] Information related to the survival time may be changed (e.g., updated or modified). The network device may notify the UE of a change in the QoS parameters related to the survival time. The AF may notify the core network device of the change. The notification may include (1) to (16) disclosed as examples of the QoS parameters related to the survival time. As another example, the notification may include information related to the reason for the change. The reason for the change may be, for example, a change in the environment of the application (e.g., a change in the time period or season in which the application is used), or may be another reason.

[0383] The core network device may request the AF to change information related to the survival time. The request may include information related to the reason for the change. The information related to the reason may include, for example, excessive requests related to the survival time from the AF, or a situation in which the requests related to the survival time from the AF are likely to be unable to be satisfied. The AF may use the request to change QoS parameters related to the survival time. This may enable, for example, flexible operation of the communication system.

[0384] As another example, a base station may request the AF to change information related to the survival time. The base station may make the request to the AF via a core network device. As another example, the UE may make the request. The UE may make the request via the base station or the core network device. The AF may use the request to change information related to the survival time. This makes it possible to prevent application interruptions due to, for example, failure to meet requirements related to the survival time in a communication system.

[0385] A plurality of pieces of information related to survival time may be set for one UE. For example, a plurality of pieces of information related to survival time may be set for one UE from a plurality of applications. The plurality of pieces of information may be, for example, a plurality of combinations of (1) to (16) disclosed as examples of QoS parameters related to survival time and / or existing QoS parameters. The UE may use the information to communicate with the base station. This enables, for example, flexible QoS control for different applications.

[0386] A plurality of such settings for one UE may be made to a core network device or a base station. The core network device and / or the base station may use the settings to perform QoS control or scheduling for the UE. This enables efficient scheduling in a communication system, for example.

[0387] One application may set multiple pieces of information related to survival time. For example, different information may be set for the application's control information and for actual data. The application may set the information for the core network device or for the UE. This may improve the efficiency of QoS control in the application, for example.

[0388] The information about the survival time may include information about a validity period. For example, when the survival time varies over time, a validity period may be set. This allows, for example, flexible QoS control in a communication system.

[0389] A default value may be set for the information regarding the survival time. The default value may be, for example, defined by a standard, determined by a core network device, determined by an AF, or determined by a base station. When the information regarding the survival time is not set, each device in the communication system may perform communication using the default value. When the aforementioned validity period expires, the default value may be used. This makes it possible to prevent malfunctions in the communication system, for example.

[0390] QoS control using survival time may be performed in the DC. In the DC, QoS control using survival time may be performed in the base station on the MCG side. This makes it possible to avoid, for example, complexity in QoS control during the DC. As another example, the SCG (Secondary Cell Group) may perform QoS control. This makes it possible, for example, to reduce the amount of processing in the MCG. As another example, the MCG and SCG may each perform QoS control. This makes it possible to improve the flexibility of QoS control.

[0391] As another example, QoS control may be performed in a cell group through which a QoS flow to be QoS controlled passes. For example, when the QoS flow passes through an MCG bearer, the MCG may perform QoS control. When the QoS flow passes through a split bearer, the MCG and SCG may each perform QoS control. This, for example, makes it possible to improve the flexibility of QoS control. As another example, when the QoS flow passes through a split bearer, the MCG may perform QoS control. This, for example, makes it possible to avoid complexity in QoS control.

[0392] As another example, a cell group performing SDAP processing may perform QoS control. The cell group may be an MCG or an SCG. This allows, for example, the same cell group to perform QoS flow mapping and QoS control, thereby reducing the amount of processing required for QoS flow mapping and QoS control.

[0393] As another example, a cell group that performs PDCP processing may perform QoS control. The QoS control may be applied, for example, when performing the processing of Variation 2 of Embodiment 3. This makes it possible to reduce the amount of processing in the communication system, for example, in the processing of Variation 2 of Embodiment 3.

[0394] As another example, a cell group that performs RLC processing may perform QoS control, which enables flexible QoS control that takes RLC ARQ into consideration, for example.

[0395] As another example, a cell group that performs MAC processing may perform QoS control. The QoS control may be applied, for example, when performing the processing of Modification 1 of Embodiment 3. This makes it possible to reduce the amount of processing in the communication system, for example, in the processing of Modification 1 of Embodiment 3.

[0396] The MCG may notify the SCG of information related to the survival time. This information may be, for example, the information (1) to (16) disclosed above as examples of QoS parameters related to the survival time. This makes it possible to prevent discrepancies in QoS control of the survival time between the MCG and the SCG, and as a result, improve the stability of the operation of the communication system.

[0397] Information regarding survival time may be acquired (or monitored). The monitored information may be, for example, (1) to (16) disclosed as examples of QoS parameters related to survival time. For example, with respect to (1) above, a survival time timer may be provided.

[0398] The above-mentioned monitoring may be performed by the UE. The layer that performs the above-mentioned monitoring in the UE may be RRC, SDAP, PDCP, RLC, or MAC. As another example, the V2X layer in the sidelink (see Non-Patent Document 28 (TS23.287)) may perform the above-mentioned monitoring. In the layer that performs the above-mentioned monitoring, for example, a survival time timer may be provided. For example, the timer may be started when a HARQ NACK or a DCI for retransmission is received. This allows, for example, the UE to quickly reflect a transmission failure in the HARQ layer in the survival time timer.

[0399] The UE may notify the base station of the information monitored as described above. RRC signaling may be used for the notification. This allows, for example, the UE to transmit a large amount of information to the base station. As another example, MAC signaling may be used for the notification. This allows, for example, the UE to notify the base station quickly. As another example, L1 / L2 signaling may be used for the notification. This allows, for example, the UE to notify the base station even more quickly. The base station may use the information to control the communication system. For example, the base station may change the coding rate in scheduling for the UE when the number of consecutive communication failures reaches a predetermined value or more. This makes it possible, for example, to prevent the expiration of the survival time.

[0400] As another example, the UE may notify the AMF of the information, which may be notified using NAS signaling, and the AMF may use the information to control the communication system.

[0401] As another example of the monitoring, the base station may perform the monitoring. For example, the CU or the DU may perform the monitoring. The layer that performs the monitoring in the base station may be RRC, SDAP, PDCP, RLC, or MAC. For example, a survival time timer may be provided in the layer that performs the monitoring. For example, the timer may be started when a HARQ NACK or a DCI for retransmission is received. This allows the base station to quickly reflect a transmission failure in the HARQ layer in the survival time timer.

[0402] The base station may report the monitored information to the UE. As another example, the base station may report the information to the AMF. The AMF may use the information to control the communication system.

[0403] As another example of the above-mentioned monitoring, the monitoring may be performed by a core NW device. The above-mentioned core NW device may be a UPF, an AMF, or an SMF. For example, the UPF may perform the monitoring for U-plane data, and the AMF may perform the monitoring for C-plane data. The AMF may perform the monitoring for small data.

[0404] According to the third embodiment, QoS control using survival time is possible for both the network device and the UE, and as a result, communication that satisfies the requirements of the application layer is possible.

[0405] Variation 1 of embodiment 3 QoS control using survival time may be used in MAC. The MAC layer of the UE and / or the base station may have a survival time timer. In the communication system, for example, transmission of data with a short time remaining until the expiration of the survival time timer may be preferentially scheduled.

[0406] A survival time timer may be provided for each logical channel, which allows for example increased flexibility in the communication system.

[0407] A parameter indicating priority in MAC scheduling (see Non-Patent Document 17 (3GPPTS38.321 V15.8.0)) may be dynamically variable. For example, a value obtained by subtracting a predetermined value (hereinafter, sometimes referred to as a priority offset) from the priority value in Non-Patent Document 17 using the time remaining until the survival timer expires may be used in scheduling. The parameter indicating priority may be a parameter in which the lower the value, the higher the priority.

[0408] The subtracted priority value may be prevented from falling below a predetermined threshold. If the subtracted priority value falls below the predetermined threshold, the UE may set the subtracted priority value to the same value as the predetermined threshold. The predetermined threshold may be defined by a standard, or may be determined by the base station and notified to the UE. This makes it possible to prevent, for example, the subtracted priority value from falling outside the range defined by the standard, thereby preventing malfunctions in the LCP. In addition, as another example, it is possible to prevent the priority from being excessively high in the priority offset.

[0409] The priority offset may be a uniform value within the survival time tolerance, which can avoid design complexity in LCP, for example.

[0410] As another example, the priority offset may be variable within the survival time tolerance. For example, when there is little time remaining until the survival time timer expires, the priority offset may be increased. This allows, for example, even when a HARQ retransmission occurs, the retransmission to be transmitted with priority, and as a result, the retransmission can be performed before the survival time timer expires.

[0411] A priority offset may be assigned for each scheduling unit of time. For example, within a time range until the expiration of the survival time timer, a higher priority offset may be set for the later time. This, in addition to the above-mentioned effects, enables flexible allocation of logical channels in the LCP. The scheduling unit of time may be a subframe, a slot, a minislot, or a symbol.

[0412] Fig. 18 is a diagram illustrating an example of assigning a priority offset to a logical channel having a survival time requirement. Fig. 18 shows an example in which, after the survival time timer is started, the priority offset is set to a larger value as the remaining time on the timer decreases.

[0413] 18 shows an example in which the time during which the priority offset value is constant varies depending on the offset value. In contrast, the time during which the priority offset value is constant may be constant regardless of the offset value. This makes it possible to avoid design complexity in the UE LCP processing, for example.

[0414] The priority offset may be predetermined by a standard. For example, a uniform offset amount may be determined. Alternatively, an offset amount may be determined for each scheduling timing. Alternatively, the offset amount may be determined in association with the range of the time remaining until the expiration of the survival time timer. As an example of the association between the range of the remaining time and the offset amount, the time range from the start of the survival time timer to its expiration may be divided, and an offset amount may be determined for each divided range. For example, an offset amount may be determined for the range from the start of the survival time timer to the remaining half until its expiration, and an offset amount may be determined for the range from the remaining half until its expiration to its expiration.

[0415] The logical channels to which the priority offset is applied may be predetermined by the standard. For example, the priority offset may be applied to a logical channel for which a survival time requirement is set. This allows, for example, the priority of the logical channel to be higher than that of other logical channels, thereby enabling the survival time requirement to be met.

[0416] As another example, the base station may determine the priority offset and notify the UE. For example, RRC signaling may be used for the notification. The notification may include information about the logical channel. The information may include information about the offset amount. The UE may apply the offset included in the notification to the logical channel included in the notification. The information about the offset amount may be the same as the offset amount predetermined by a standard. This allows the base station to notify the UE of more information, for example, thereby improving the flexibility in setting the priority offset.

[0417] As another example of the notification, MAC signaling may be used. The notification may include information about a logical channel or information about an offset. The information about the offset may be information similar to an offset amount predetermined in a standard. The UE may apply the offset included in the notification to the logical channel included in the notification. This allows the UE to quickly apply the offset, for example.

[0418] As another example of the notification, L1 / L2 signaling may be used. The notification may include information about the logical channel or information about the offset. The notification may be included in a DCI including the scheduling grant, or may be included in a different DCI, or may be transmitted by a different L1 / L2 signaling. The information about the offset may be the same as the offset amount predetermined in the standard, or may be the offset amount applied in the grant. This may enable the UE to apply the offset more quickly, for example.

[0419] A plurality of pieces of information regarding the offset amount may be provided. The plurality of pieces of information may be defined by a standard, may be determined by the base station and notified to the UE, or may be determined by an upper network device and notified to the UE via the base station. The base station may notify the UE of an identifier of the information to be used among the plurality of pieces of information. The identifier may be notified using RRC signaling, MAC signaling, or L1 / L2 signaling. The notification may include information regarding the logical channel to which the offset is applied. The UE may derive the information to be used using the identifier. The base station may determine the information to be used using settings from an upper network device, such as QoS parameters. Alternatively, the base station may determine the information to be used using information regarding network slicing. This, for example, makes it possible to reduce the amount of signaling from the base station to the UE.

[0420] The following (1) to (6) are disclosed as examples of information regarding the amount of priority offset that the base station notifies the UE.

[0421] (1) Survival time value.

[0422] (2) Information about the logical channel to which the priority offset applies.

[0423] (3) The number of priority offset patterns to be assigned.

[0424] (4) The priority offset value.

[0425] (5) The remaining time on the survival timer to which the priority offset is applied.

[0426] (6) A combination of (1) to (5) above.

[0427] The information (1) above may be a value of a survival time timer. The information (1) above may be information including, for example, the allowable number of consecutive undelivered transmissions and a transmission period. For example, the information (1) above may be an initial value of a survival time timer. This makes it possible to avoid complexity in setting a priority offset in the UE, for example.

[0428] The information (2) above may be, for example, a logical channel identifier (LCID), which allows, for example, the MAC layer of the UE to quickly identify the logical channel to which the priority offset is to be assigned.

[0429] The information in (3) above may be the number of priority offset stages assigned to the logical channel. The number of stages may or may not include the case where there is no priority offset. For example, in a case where a certain priority offset is assigned from when the remaining time of the survival time timer is less than halfway until the timer expires, the value of (3) above may be 1. This allows, for example, the MAC layer of the UE to quickly grasp the number of priority offset stages. As a result, the processing speed in the UE can be improved.

[0430] The information (4) above may be the value of the priority offset assigned to the logical channel. As another example, the information (4) above may be an increment of the priority offset value. This allows, for example, the UE to appropriately assign a priority offset to the logical channel. As a result, the stability of the communication system can be improved.

[0431] The information (5) above may be, for example, the value of the timer that starts the assignment of the offset (4) above. This allows, for example, the UE to appropriately assign a priority offset to the logical channel. As a result, the stability of the communication system can be improved.

[0432] The information items (4) and (5) may be provided in multiple numbers, for example, the number of values ​​of the information item (3) may be provided. This allows, for example, the UE to appropriately assign a priority offset to the logical channel. As a result, the stability of the communication system can be improved.

[0433] The UE may use the information notified by the base station to offset the priority value. The offset may be assigned for each logical channel or for each HARQ process ID.

[0434] The UE may start the survival time timer upon receiving an HARQ NACK, or upon receiving scheduling information for HARQ retransmission. The base station may start the survival time timer upon transmitting an HARQ NACK to the UE, or upon transmitting scheduling information for HARQ retransmission. This makes it possible to prevent discrepancies in the survival time timer values ​​between the UE and the base station, and as a result, to prevent malfunctions in the communication system.

[0435] The method disclosed in this first modification may be used after the expiration of the survival time timer. For example, a predetermined priority offset may be assigned after the expiration of the survival time timer. Furthermore, for example, a predetermined priority offset may be assigned during the Application Recovery Time described in Non-Patent Document 23 (TR22.832). The priority offset may be set after the expiration of the survival time timer in the same manner as the priority offset was set before the expiration of the timer. The UE may use this setting to assign a priority offset after the expiration of the survival time timer. This may enable, for example, rapid recovery from a state in which an application is disconnected due to the expiration of the survival time timer.

[0436] According to this first modification, the UE can transmit data with priority when there is little time left until the expiration of the survival time timer, thereby preventing the expiration of the survival time timer.

[0437] Variation 2 of embodiment 3 A survival time may be used to control packet duplication. For example, packet duplication may be automatically initiated when the survival time timer starts. For example, the UE may automatically initiate packet duplication upon receiving scheduling information for HARQ retransmissions. The scheduling information may include scheduling information for transmission of the duplicated packet.

[0438] The above problem can lead to the following problems. There is discussion about limiting the number of packets to a maximum of four (see Non-Patent Document 24 (3GPP RP-192590)). In this case, the number of packets to be automatically replicated is not disclosed, which can lead to operational discrepancies between the UE and the base station. For example, even though the base station expects a packet replication count of four, the UE may replicate a packet and transmit it in two. This can lead to inefficient use of reception resources at the base station.

[0439] In this second modification, a method for solving the above-mentioned problems will be disclosed.

[0440] The number of packet duplications is controlled using the survival time. The UE implicitly changes the number of packet duplications using the survival time. For example, the UE may vary the number of packet duplications using the time remaining until the survival timer expires. The base station implicitly controls the number of packet duplications using the survival time timer. For example, the base station may schedule transmission resources used by the UE using the time remaining until the survival timer expires. For example, the number of packet duplications may increase as the expiration of the survival time timer approaches.

[0441] Implicit packet replication may be a method in which activation / deactivation of a leg used in packet replication is controlled implicitly.

[0442] CA may be used for implicit packet duplication. The base station may notify the UE of information about a cell used in implicit packet duplication. The UE may use the information to transmit and receive data to and from the base station using the cell in implicit packet duplication. This may provide, for example, a frequency diversity effect in implicit packet duplication. As a result, reliability in implicit packet duplication may be improved.

[0443] DC may be used for implicit packet duplication. The base station may notify the UE of information about cells used in implicit packet duplication. The notification from the base station to the UE may include information about cells in the MCG or information about cells in the SCG. The UE may notify a cell group added in DC of information indicating that implicit packet duplication will be started. The cell group may be an SCG or an MCG. The cell group may start receiving or transmitting the duplicated packets using the notification from the UE. This may provide frequency diversity and spatial diversity effects in implicit packet duplication, thereby improving the reliability of implicit packet duplication.

[0444] CA and DC may be used in combination for implicit packet duplication. In packet duplication using the combination of CA and DC, the UE may notify the cell group added in DC of information indicating that implicit packet duplication will be started.

[0445] Fig. 19 illustrates an example of implicit control of the number of packet copies in a logical channel with a survival time requirement, where the number of packet copies is increased as the remaining time on the survival time timer decreases after the timer is started.

[0446] 19 shows an example in which the time period during which the number of packet copies becomes constant varies depending on the number of copies. In contrast, the time period during which the number of packet copies becomes constant may be constant regardless of the number of copies. This makes it possible to avoid complexity in the design of packet copy processing by the UE, for example.

[0447] The number of packet copies may be predetermined by a standard. For example, a uniform number of copies may be determined. Alternatively, the number of packet copies may be determined for each scheduling timing. Alternatively, the number of packet copies may be determined in association with the range of the time remaining until the expiration of the survival time timer. As an example of the association between the range of the remaining time and the number of packet copies, the time range from the start of the survival time timer to its expiration may be divided, and the number of packet copies may be determined for each divided range. For example, a number of packet copies may be determined for the range from the start of the survival time timer to the remaining half until its expiration, and a number of packet copies may be determined for the range from the remaining half until its expiration to its expiration.

[0448] The logical channels to which the implicit control of the number of packet replications is applied may be predetermined by the standard. For example, the implicit control of the number of packet replications may be applied to logical channels with a survival time requirement. This allows, for example, packet replication to be automatically applied to the logical channel, thereby improving the reliability of the logical channel.

[0449] As another example, the base station may determine the packet duplication number and notify the UE. For example, RRC signaling may be used for the notification. The notification may include information about the logical channel. The information may include information about the packet duplication number or information about the remaining time of a survival time timer. The UE may apply the packet duplication number included in the notification to the logical channel included in the notification. The information about the packet duplication number may be similar to the packet duplication number predetermined by a standard. This allows the base station to notify the UE of more information, for example, thereby improving flexibility in implicit control of the packet duplication number.

[0450] As another example of the notification, MAC signaling may be used. The notification may include information about a logical channel, information about the remaining time of a survival time timer, or information about the number of packet duplications. The information about the number of packet duplications may be the same as the number of packet duplications predetermined by a standard. The UE may apply the number of packet duplications included in the notification to the logical channel included in the notification. This allows the UE to quickly reflect the control of the number of packet duplications, for example.

[0451] As another example of the notification, L1 / L2 signaling may be used. The notification may include information about the logical channel, the remaining time of the survival time timer, or the number of packet duplications. The notification may be included in a DCI including the scheduling grant, a different DCI, or a different L1 / L2 signaling. The information about the number of packet duplications may be the same as the number of packet duplications predefined in the standard, or may be the number of packet duplications applied in the grant. This may enable the UE to more quickly apply control over the number of packet duplications, for example.

[0452] A plurality of pieces of information regarding the number of packet replications may be provided. The plurality of pieces of information may be defined by a standard, may be determined by the base station and notified to the UE, or may be determined by an upper network device and notified to the UE via the base station. The base station may notify the UE of an identifier of the information to be used among the plurality of pieces of information. The identifier may be notified using RRC signaling, MAC signaling, or L1 / L2 signaling. The notification may include information regarding the logical channel to which the number of packet replications is applied. The UE may derive the information to be used using the identifier. The base station may determine the information to be used using settings from an upper network device, such as QoS parameters. Alternatively, the base station may determine the information to be used using information regarding network slicing. This, for example, makes it possible to reduce the amount of signaling from the base station to the UE.

[0453] The following (1) to (8) are disclosed as examples of information related to implicit control of the number of packet duplications that the base station notifies the UE of.

[0454] (1) Survival time value.

[0455] (2) Information about the radio bearer to which implicit control of the number of packet duplications applies.

[0456] (3) Number of packet duplication patterns.

[0457] (4) Number of packet duplications.

[0458] (5) Whether DC applies.

[0459] (6) Information about cells used for packet duplication.

[0460] (7) The remaining time on the survival time timer to which the packet duplication number is applied.

[0461] (8) A combination of (1) to (7) above.

[0462] The information (1) above may be the initial value of a survival time timer, or may include, for example, the number of consecutive undelivered transmissions allowed and a transmission period, which may reduce the complexity of packet duplication control in the UE.

[0463] The information (2) above may be, for example, a data radio bearer identifier (DRB-ID) before packet duplication, which allows, for example, the PDCP layer of the UE to quickly identify the radio bearer for which implicit packet duplication control is performed.

[0464] The information in (3) above may be the number of packet duplication patterns given for the radio bearer. The number of stages may include or exclude the case where there is no packet duplication. For example, if packet duplication with a duplication count of 4 is performed between the time when the survival time timer reaches halfway and the timer expires, the value in (3) above may be 1. This allows, for example, the PDCP layer of the UE to quickly determine the number of packet duplication stages. As a result, the processing speed in the UE can be improved.

[0465] The information (4) above may be the number of packet duplications in the radio bearer. As another example, the information (4) above may be an increment in the number of packet duplications. This allows, for example, the UE to appropriately control packet duplications in the radio bearer. As a result, the stability of the communication system can be improved.

[0466] As another example of the information (4) above, information on the number of packet duplications in each of the MCG and SCG may be included. For example, this information may be included when DC is used in implicit packet duplication. This allows, for example, improved flexibility in implicit packet duplication.

[0467] The information in (5) above may be, for example, information indicating whether DC is used for implicit packet duplication at the timing in (7) above. The UE may start or stop packet duplication using DC using the information in (5) above. This allows, for example, improved flexibility in implicit packet duplication.

[0468] The information in (6) above may be, for example, a cell identifier. The information in (6) above may include information about a cell of an MCG used in implicit packet duplication, information about a cell of an SCG, or both. The UE may transmit and receive data to and from a base station using the cell indicated in the information in (6) above. This may reduce the amount of processing related to implicit packet duplication in the UE, for example.

[0469] The information (7) may be, for example, the number of copies (4) and / or the value of the timer that starts the DC (5). This allows, for example, the UE to appropriately control packet duplication in the radio bearer. As a result, the stability of the communication system can be improved.

[0470] The information items (4) to (7) may be provided in plural, for example, the number of pieces of information may be the same as the value of the information item (3). This allows, for example, the UE to appropriately control packet duplication of the radio bearer, thereby improving the stability of the communication system.

[0471] The base station may change the implicit packet duplication setting. The base station may change the implicit packet duplication setting, for example, by using a measurement report from the UE. The base station may notify the UE of the changed setting. The notification of the changed setting may include, for example, the information (1) to (8) disclosed as information related to implicit control of the number of packet duplications. This allows the base station to select an appropriate cell or cell group depending on the quality of communication with the UE, thereby improving the reliability of communication.

[0472] As in the first modification of the third embodiment, the UE may start the survival time timer upon receiving an HARQ NACK, or upon receiving scheduling information for HARQ retransmission. The base station may start the survival time timer upon transmitting an HARQ NACK to the UE, or upon transmitting scheduling information for HARQ retransmission. This makes it possible to prevent discrepancies in the survival time timer values ​​between the UE and the base station, and as a result, to prevent malfunctions in the communication system.

[0473] The notification from the UE to the cell group may be performed using L1 / L2 signaling, MAC signaling, or RRC signaling. The L1 / L2 signaling may be, for example, SR. By using L1 / L2 signaling for the notification by the UE, for example, the UE can quickly notify the cell group.

[0474] The UE may notify the cell group of information indicating that implicit packet duplication is to be stopped. The notification may be made, for example, when a survival time timer is stopped or initialized. The cell group may use the notification from the UE to stop receiving or not transmitting duplicated packets. This may enable, for example, efficient use of frequency and time resources in the cell group. The notification from the UE to the cell group indicating the stop of implicit packet duplication may be made in the same manner as the notification indicating the start of implicit packet duplication.

[0475] The UE may request the base station to change the settings related to implicit packet duplication. The change request may be, for example, a request to increase the number of duplications, a request to decrease the number of duplications, a request to enable packet duplication using DC, a request to disable packet duplication using DC, or a combination of two or more of the above. The base station may use the request to change the settings related to implicit packet duplication. The base station may notify the UE of the changed settings. The notification of the changed settings may include, for example, the information (1) to (8) disclosed as information related to implicit control of the number of packet duplications. This may, for example, improve the reliability of implicit packet duplication.

[0476] The request may be made using, for example, RRC signaling. The RRC signaling may be, for example, signaling requesting RRC reconfiguration. The signaling may be newly provided. This may enable, for example, the UE to transmit more information to the base station. As another example, the request may be made using MAC signaling. This may enable, for example, the UE to quickly notify the base station of the request. As another example, the request may be made using L1 / L2 signaling. This may enable, for example, the UE to more quickly notify the base station of the request.

[0477] The method disclosed in this second modification may be used after the expiration of the survival time timer. For example, implicit packet replication may be performed after the expiration of the survival time timer, or implicit packet replication may be performed during the application recovery time described in Non-Patent Document 23 (TR22.832). The setting of implicit packet replication after the expiration of the survival time timer may be performed in the same manner as the setting of implicit packet replication before the expiration of the timer. The UE may use this setting to perform implicit packet replication after the expiration of the survival time timer. This makes it possible to quickly recover from a state in which an application is disconnected due to the expiration of the survival time timer, for example.

[0478] According to this modification 2, the UE can improve the reliability of data transmission when there is little time left until the expiration of the survival time timer, and as a result, it is possible to prevent the expiration of the survival time timer.

[0479] Variation 3 of embodiment 3 Scheduling using the survival time may be performed. For example, the remaining time of the survival time timer may be used to automatically change the scheduling for the UE. The UE may change and use the scheduling for its own UE using information about the remaining time of the survival time timer.

[0480] As examples of automatic schedule changes using survival time, the following (1) to (7) are disclosed.

[0481] (1) Configured Grant.

[0482] (2) Information about the cells used for transmission and reception.

[0483] (3) Information about the beam and / or antenna panel used by the UE.

[0484] (4) Information about the beams, antenna panels, and / or TRPs used by the base station.

[0485] (5) Information about the base station to which the UE transmits and receives data.

[0486] (6) Information about the UE that transmits and receives data.

[0487] (7) A combination of (1) to (6) above.

[0488] The previously set grant (1) may be, for example, a grant that allocates a large frequency resource when the remaining time on the survival timer reaches a predetermined time. This allows the UE to transmit uplink data at a low coding rate, for example. As a result, the reliability of communication can be improved.

[0489] In the above (2), for example, when the remaining time on the survival time timer reaches a predetermined time, a cell using a lower frequency may be used. This makes it possible to select a cell using a frequency that is less likely to be blocked when there is little time left until the survival time timer expires. As a result, it is possible to improve the reliability of communication.

[0490] In the above (3), for example, when the remaining time on the survival time timer reaches a predetermined time, the beam and / or antenna panel to be used by the UE may be designated. The beam to be used by the UE may be, for example, an SRS beam, or may be designated by information related to a DMRS antenna port (e.g., a DMRS antenna port number). The above (3) may be applied, for example, to uplink communications. This may, for example, improve the reliability of uplink communications.

[0491] The base station may measure uplink signals from the UE to each antenna panel and / or TRP of the base station. The uplink signals measured by the base station may be SRS or DMRS. The base station may measure the shadowing frequency. The base station may retain the uplink measurement results. For example, the base station may retain information (e.g., a database) regarding the reliability of the uplink signals. This allows the base station to quickly select a beam, antenna panel, and / or TRP with high reliability, for example.

[0492] In the above (4), for example, when the remaining time on the survival time timer reaches a predetermined time, the beam and / or antenna panel to be used by the base station may be designated. The above (4) may be applied, for example, to downlink communication. This makes it possible to improve the reliability of downlink communication, for example.

[0493] The UE may measure downlink signals from each antenna panel and / or TRP of the base station. The UE may, for example, measure CSI-RS or SS blocks from the base station. The UE may measure information about the frequency of occlusion of the downlink signals. The UE may report information about the measurement results of the downlink signals to the base station. The UE may, for example, report measurement results about the frequency of occlusion of the downlink signals to the base station. The information about the frequency of occlusion may, for example, be the number of times the received strength of the downlink signals falls below a predetermined threshold within a predetermined time period, or the time during which the received strength of the downlink signals falls below a predetermined threshold. The base station may use the information to determine the beam, antenna panel, and / or TRP to be used for downlink communication with the UE. This makes it possible, for example, to avoid beams that are prone to occlusion in downlink communication between the base station and the UE. As a result, the reliability of downlink communication can be improved.

[0494] Regarding the above (3) and / or (4), the base station may notify the measurement results of the uplink signal and / or the downlink signal to an NWDAF (Network Data Analytics Function, see Non-Patent Document 31 (TS23.288)). The measurement results may include, for example, information about the frequency of occlusion. An interface may be provided between the base station and the NWDAF. The NWDAF may use the measurement results to generate or store information (for example, a database) about the reliability of the uplink signal and / or the downlink signal. The NWDAF may notify the base station of the reliability information. The base station may use the reliability information to determine the beams and / or antenna panels to be used by the UE, or may determine the beams and / or antenna panels to be used by the base station itself. This, for example, makes it possible to reduce the amount of processing at the base station regarding the above (3) and (4).

[0495] The UE may notify the NWDAF of the measurement results of the downlink signal. An interface may be provided between the UE and the NWDAF. The NWDAF may generate or store information about the reliability of the downlink signal using the information from the UE. This may, for example, reduce the amount of processing in the base station.

[0496] As another example, information about the shading frequency may be notified to the NWDAF by OAM (Operations, Administration, and Maintenance). The OAM may derive the shading frequency using a measurement result of the UE. The OAM may include the information about the shading frequency in the notification of information about RSRP, RSRQ, or SINR to the NWDAF. This may reduce the amount of signaling in a communication system, for example.

[0497] As another example, the NWDAF may derive information regarding the occlusion frequency. The NWDAF may derive information regarding the occlusion frequency, for example, using information regarding RSRP, information regarding RSRQ, and / or information regarding SINR notified to the NWDAF by OAM (Operations, Administration, and Maintenance). The NWDAF may notify the information regarding the occlusion frequency to the OAM, the base station, the AMF, the SMF, the UPF, the PCF, or the AF (Application Function). For example, the base station may use the information regarding the occlusion frequency to determine information regarding (3) and / or (4) above. This, for example, can reduce the amount of signaling in the communication system and improve the reliability of communication between the base station and the UE.

[0498] The above (5) may be, for example, an identifier of a base station to which the UE transmits and receives data (e.g., gNB-ID), an identifier indicating whether the base station is a master base station or a secondary base station, or a serial number assigned to a base station to which the UE connects. Each of the above identifiers may be applied, for example, when the UE uses a DC configuration, or when multi-connectivity is used (e.g., when the UE connects to three or more base stations). This may provide, for example, a spatial diversity effect, thereby improving reliability.

[0499] The above (6) may be, for example, a UE identifier (e.g., UE-ID) or an identifier assigned to each UE in the application device. The above (6) may be applied, for example, to a case where a plurality of UEs are installed in one application device. This may provide, for example, the same effect as the above (5).

[0500] The base station may notify the UE of scheduling information, and the UE may use the information to transmit and receive data to and from the base station.

[0501] The following (1) to (5) are disclosed as examples of information related to scheduling that the base station notifies the UE.

[0502] (1) Survival time value.

[0503] (2) Number of automatic scheduling patterns.

[0504] (3) Information regarding automatic scheduling.

[0505] (4) The remaining time on the survival timer to which automatic scheduling is applied.

[0506] (5) A combination of (1) to (4) above.

[0507] The information (1) above may be the same as the information (1) disclosed as the information on the priority offset amount in Variation 1 of Embodiment 3. This makes it possible to avoid complexity in setting automatic scheduling in the UE, for example.

[0508] The information (2) above may be the same as the information (3) disclosed as the information on the priority offset amount in Variation 1 of Embodiment 3. This allows, for example, the UE to quickly grasp the number of stages of automatic scheduling, thereby enabling an improvement in the processing speed in the UE.

[0509] The information (3) above may be the information (1) to (7) disclosed as examples of automatic scheduling changes using survival time in this Modification 3. This enables, for example, appropriate scheduling from the base station to the UE, which in turn improves the stability of the communication system.

[0510] The information in (4) above may be the same as the information in (5) disclosed as the information on the priority offset amount in Variation 1 of Embodiment 3. This enables, for example, appropriate scheduling from the base station to the UE, thereby improving the stability of the communication system.

[0511] The information items (3) and (4) may be provided in multiple numbers, for example, the number of pieces of information may be the same as the value of the information item (2). This allows, for example, appropriate scheduling from the base station to the UE, thereby improving the stability of the communication system.

[0512] According to the third modification, the base station can perform highly reliable scheduling for data transmission to the UE when there is little time left until the expiration of the survival time timer, thereby making it possible to prevent the expiration of the survival time timer.

[0513] The above-described embodiments and their modifications are merely examples, and the embodiments and their modifications can be freely combined. Furthermore, any of the components of the embodiments and their modifications can be modified or omitted as appropriate.

[0514] For example, in the above-described embodiments and their modifications, 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 the above-described embodiments and their modifications, the processing described as being performed in subframe units may also be performed in TTI units, slot units, subslot units, or minislot units.

[0515] For example, the methods disclosed in the above-described embodiments and their modified examples may be applied not only to V2X (Vehicle-to-everything) services but also to services that use SL communication. SL communication is used in a variety of services, such as proximity-based services, public safety, communication between wearable devices, and communication between devices in factories. The methods disclosed in the above-described embodiments and their modified examples may be applied to SL communication used in such a variety of services.

[0516] Although the present disclosure has been described in detail, the above description is illustrative in all respects and does not limit the present disclosure to the above. It is understood that countless variations not illustrated can be envisioned without departing from the scope of the present disclosure. [Explanation of symbols]

[0517] 200, 210 communication system, 202 communication terminal device, 203 base station device.

Claims

1. A terminal device having a plurality of SIMs (Subscriber Identity Modules) and configured to connect to a plurality of networks using the plurality of SIMs, the plurality of networks includes a first network and a second network; the terminal device is configured to transmit, to a base station device of the first network, information indicating whether the terminal device receives paging from the first network; the information indicating that a paging of a voice call is prioritized over a paging other than the paging of the voice call; Terminal device.

2. the first network includes an Access and Mobility Management Function (AMF); The terminal device is configured to receive, from the AMF, NAS (Non-Access Stream) signaling including information indicating whether the terminal device receives paging from the first network. The terminal device according to claim 1 .

3. The NAS signaling includes information regarding prioritized paging. The terminal device according to claim 2 .

4. a plurality of networks including a first network and a second network; a terminal device having a plurality of SIMs (Subscriber Identity Modules) and configured to connect to the plurality of networks using the plurality of SIMs, the first network includes the base station device; the base station device is configured to receive, from the terminal device, information indicating whether the terminal device will receive paging from the first network; the information indicating that a paging of a voice call is prioritized over a paging other than the paging of the voice call; Base station equipment.

5. a plurality of networks including a first network and a second network; a terminal device having a plurality of SIMs (Subscriber Identity Modules) and configured to connect to the plurality of networks using the plurality of SIMs, the first network includes a base station device; the terminal device is configured to transmit, to the base station device, information indicating whether the terminal device will receive paging from the first network; the information indicating that a paging of a voice call is prioritized over a paging other than the paging of the voice call; Communication system.

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