KR20210119791A - Method and apparatus of paging for multi usim user equipment in communication system - Google Patents

Abstract

A paging method and apparatus in a communication system are disclosed. A method of operating a terminal comprises the steps of: establishing a radio resource control (RRC) connection with a first base station; establishing an RRC connection with a second base station; transitioning the RRC connection state with the first base station and the second base station to an RRC inactive state; detecting a paging message by monitoring a first paging occasion configured with the first base station and a second paging occasion configured with the second base station; receiving a first paging message from the first base station through the first paging occasion as a result of detection of the paging message; and performing an RRC reconfiguration procedure with the first base station. The present invention can avoid collision among paging messages of different base stations to improve performance of a communication system.

Description

Paging method and apparatus of a multi-SIM terminal in a communication system

The present invention relates to a method and apparatus for paging a terminal in a communication system, and more particularly, to a method of operating a terminal supporting paging with base stations belonging to different public land mobile networks (PLMNs).

The communication system may include a core network, a base station (eg, a macro base station, a small base station, a relay, etc.), and user equipment (UE). In a communication system supporting 4G communication technology (eg, long term evolution (LTE) technology), the core network includes a mobility management entity (MME), a serving gateway (SGW), a packet data network (PDN) gateway (PGW), etc. may include In a communication system supporting 5G communication technology (eg, new radio (NR) technology), the core network may include an access and mobility function (AMF), a user plane function (UPF), a session management function (SMF), and the like. have.

Communication between the base station and the terminal is performed by various radio access technologies (RATs) (eg, 4G communication technology, 5G communication technology, wireless broadband (WiBro) technology, wireless local area network (WLAN) technology, wireless personal area network (WPAN) technology). etc.) can be performed. A communication system supporting 5G communication technology may require an improved terminal location and mobility management technology than a communication system supporting the existing 3G/4G communication technology in order to efficiently support various services and requirements. Accordingly, a communication system supporting 5G communication technology may require a multi-USIM terminal capable of mounting one or more universal subscriber identity modules (USIMs).

The base station that has obtained the downlink signal to be transmitted to the terminal in the inactive state may perform paging to transition the terminal in the inactive state to the RRC connected state. In addition, the terminal may receive a paging message from the base station to transition the operating state to the RRC connected state. However, in the case of a multi-sim terminal, the terminal may search for each PLMN in order to search for a paging message, which may cause a collision between paging messages having different PLMNs.

An object of the present invention for solving the above problems relates to a method and apparatus for paging a multi-USIM (universal subscriber identity module) terminal in a communication system, and more particularly, to a different PLMN An object of the present invention is to provide a paging operation method with base stations belonging to (public land mobile network).

In order to achieve the above object, a method of operating a terminal in a wireless communication system according to an embodiment of the present invention includes the steps of: establishing a radio resource control (RRC) connection with a first base station (RRC configuration); establishing an RRC connection with a second base station; Transitioning the RRC connection state with the first base station and the second base station to a radio resource control (RRC) inactive state; discovering a paging message by monitoring a first paging occasion configured with the first base station and a second paging occasion configured with the second base station; receiving a first paging message from the first base station through a first paging occasion as a result of searching for the paging message; and performing an RRC reconfiguration procedure with the first base station.

Here, the second base station may belong to a second PLMN that is a different PLMN from the first PLMN that is a public land mobile network (PLMN) of the first base station.

Here, the terminal includes: a first universal subscriber identity module (USIM) to which a first international mobile subscriber identity (IMSI) value including the first PLMN identifier (ID) is assigned; and a second USIM to which a second IMSI value including the second PLMN ID is assigned.

Here, the first paging message may further include identification information (PLMN ID (PLMN ID)) of the first PLMN.

Here, the identification information of the first PLMN may be indicated by a user equipment (UE) paging identifier (IE) information element (IE) of the paging message.

Here, the step of searching for the paging message comprises searching for a physical downlink control channel (PDCCH) including downlink control information (DCI) through the first paging occasion, and the first paging occasion DCI may include a cyclic redundancy check (CRC) scrambled by a paging radio network temporary identity (P-RNTI) of the first base station.

Here, receiving a second paging message from the second base station through a second paging occasion as a result of the search for the paging message; and performing an RRC reconfiguration procedure with the second base station.

Here, the step of searching for the paging message comprises searching for a PDCCH including a DCI through the second paging occasion, and the DCI of the second paging occasion is the P- of the first base station. It may include a cyclic redundancy check (CRC) scrambling by the P-RNTI of the second base station, which is a separate P-RNTI from the RNTI.

A terminal in a wireless communication system according to another embodiment for achieving the above object of the present invention, comprising: a processor; a memory in electronic communication with the processor; and instructions stored in the memory, wherein when the instructions are executed by the processor, the instructions allow the terminal to establish a radio resource control (RRC) connection with a first base station (RRC configuration) do; establish an RRC connection with a second base station; Transitioning an RRC connection state with the first base station and the second base station to a radio resource control (RRC) inactive state; searching for a paging message by monitoring a first paging occasion configured with the first base station and a second paging occasion configured with the second base station; receiving a first paging message from the first base station through a first paging occasion as a result of searching for the paging message; And it can operate to cause to perform the RRC reconfiguration (RRC reconfiguration) procedure with the first base station.

Here, the second base station may belong to a second PLMN that is a different PLMN from the first PLMN that is a public land mobile network (PLMN) of the first base station.

Here, the terminal includes: a first universal subscriber identity module (USIM) to which a first international mobile subscriber identity (IMSI) value including the first PLMN identifier (ID) is assigned; and a second USIM to which a second IMSI value including the second PLMN ID is assigned.

Here, the first paging message may further include identification information (PLMN ID (PLMN ID)) of the first PLMN.

Here, the identification information of the first PLMN may be indicated by a user equipment (UE) paging identifier (IE) information element (IE) of the paging message.

Here, the instructions include: receiving a second paging message from the second base station through a second paging occasion as a result of searching for the paging message; and may further operate to cause performing an RRC reconfiguration procedure with the second base station.

Here, the second paging occasion may be set to be different from the first paging occasion.

Here, the instructions, in operating to cause searching for the paging message, search for a physical downlink control channel (PDCCH) including downlink control information (DCI) through the first paging occasion and the DCI may indicate a physical downlink shared channel (PDSCH) that is a transmission resource of the paging message from the first base station.

Here, the DCI includes a cyclic redundancy check (CRC) scrambled by a paging radio network temporary identity (P-RNTI) of the first base station, and operates to cause reception of the first paging message. In this case, based on the P-RNTI of the first base station, it may operate to cause reception of the first paging message through the transmission resource indicated by the DCI.

Here, the P-RNTI of the first base station may be set to be different from the P-RNTI value of the second base station.

According to the present invention, in a 5G mobile communication system, each of the base stations having different public land mobile network (PLMN) values transmits a paging message including the PLMN information of the base station, so that paging messages of different base stations are interspersed with each other. collision can be avoided. Accordingly, the performance of the communication system may be improved.

According to the present invention, in a 5G mobile communication system, a terminal including a multi-USIM (universal subscriber identifier module) may not search for a paging message for each PLMN by receiving a paging message further including PLMN information. Accordingly, the performance of the communication system can be improved.

1 is a conceptual diagram illustrating an embodiment of a communication system.
2 is a block diagram showing a first embodiment of a communication node constituting a communication system.
3 is a conceptual diagram illustrating an embodiment of a communication system including a core network.
4 is a flowchart illustrating an embodiment of a method of paging operation of communication nodes.

Since the present invention can have various changes and can have various embodiments, specific embodiments are illustrated in the drawings and described in detail. However, this is not intended to limit the present invention to specific embodiments, and it should be understood to include all modifications, equivalents and substitutes included in the spirit and scope of the present invention.

Terms such as first, second, etc. may be used to describe various elements, but the elements should not be limited by the terms. The above terms are used only for the purpose of distinguishing one component from another. For example, without departing from the scope of the present invention, a first component may be referred to as a second component, and similarly, a second component may also be referred to as a first component. and/or includes a combination of a plurality of related listed items or any of a plurality of related listed items.

When a component is referred to as being “connected” or “connected” to another component, it is understood that the other component may be directly connected or connected to the other component, but other components may exist in between. it should be On the other hand, when it is mentioned that a certain element is "directly connected" or "directly connected" to another element, it should be understood that the other element does not exist in the middle.

The terms used in the present application are only used to describe specific embodiments, and are not intended to limit the present invention. The singular expression includes the plural expression unless the context clearly dictates otherwise. In the present application, terms such as “comprise” or “have” are intended to designate that a feature, number, step, operation, component, part, or combination thereof described in the specification exists, but one or more other features It should be understood that this does not preclude the existence or addition of numbers, steps, operations, components, parts, or combinations thereof.

Unless defined otherwise, all terms used herein, including technical and scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Terms such as those defined in a commonly used dictionary should be interpreted as having a meaning consistent with the meaning in the context of the related art, and should not be interpreted in an ideal or excessively formal meaning unless explicitly defined in the present application. does not

Hereinafter, preferred embodiments of the present invention will be described in more detail with reference to the accompanying drawings. In describing the present invention, in order to facilitate the overall understanding, the same reference numerals are used for the same components in the drawings, and duplicate descriptions of the same components are omitted.

A communication system to which embodiments according to the present invention are applied will be described. The communication system to which the embodiments according to the present invention are applied is not limited to the contents described below, and the embodiments according to the present invention can be applied to various communication systems. Here, a communication system may be used in the same sense as a communication network (network).

Throughout the specification, a terminal is a mobile station (mobile station, MS), a mobile terminal (MT), an advanced mobile station (AMS), a high reliability mobile station (HR-MS) ), subscriber station (SS), portable subscriber station (PSS), access terminal (AT), user equipment (terminal), machine type communication device (machine type communication device, MTC device) and the like, and may include all or some functions of MT, MS, AMS, HR-MS, SS, PSS, AT, UE, and the like.

In addition, the base station (base station, BS) is an advanced base station (advanced base station, ABS), a high reliability base station (high reliability base station, HR-BS), a Node B (node B), an advanced node B (evolved node B, eNodeB), an access point (AP), a radio access station (RAS), a base transceiver station (BTS), a mobile multihop relay (MMR)-BS, a relay serving as a base station station, RS), a relay node (RN) serving as a base station, an advanced relay station (ARS) serving as a base station, and a high reliability relay station (HR) serving as a base station -RS), small base station [femto base station (femto BS), home node B (home node B, HNB), home eNodeB (HeNB), pico base station (pico BS), macro base station (macro BS), micro base station (micro BS) ), etc.], etc., may include all or part of the functions of ABS, NodeB, eNodeB, AP, RAS, BTS, MMR-BS, RS, RN, ARS, HR-RS, small base station, etc. have.

The base station configures one or more cells, and the terminal establishes an RRC connection with at least one cell of the corresponding base station. Here, the cell with which the RRC connection is established is referred to as a serving cell.

1 is a conceptual diagram illustrating a first embodiment of a communication system.

1, the communication system 100 is a plurality of communication nodes (110-1, 110-2, 110-3, 120-1, 120-2, 130-1, 130-2, 130-3, 130-4, 130-5, 130-6). Here, the communication system 100 may be referred to as a “communication network”. Each of the plurality of communication nodes may support at least one communication protocol. For example, each of the plurality of communication nodes may include a code division multiple access (CDMA)-based communication protocol, a wideband CDMA (WCDMA)-based communication protocol, a time division multiple access (TDMA)-based communication protocol, and a frequency division multiple (FDMA)-based communication protocol. access) based communication protocol, OFDM (orthogonal frequency division multiplexing) based communication protocol, OFDMA (orthogonal frequency division multiple access) based communication protocol, SC (single carrier)-FDMA based communication protocol, NOMA (non-orthogonal multiple) access)-based communication protocol, space division multiple access (SDMA)-based communication protocol, and the like may be supported. Each of the plurality of communication nodes may have the following structure.

2 is a block diagram showing a first embodiment of a communication node constituting a communication system.

Referring to FIG. 2 , the communication node 200 may include at least one processor 210 , a memory 220 , and a transceiver 230 connected to a network to perform communication. In addition, the communication node 200 may further include an input interface device 240 , an output interface device 250 , a storage device 260 , and the like. Each component included in the communication node 200 may be connected by a bus 270 to communicate with each other.

The processor 210 may execute a program command stored in at least one of the memory 220 and the storage device 260 . The processor 210 may mean a central processing unit (CPU), a graphics processing unit (GPU), or a dedicated processor on which methods according to embodiments of the present invention are performed. Each of the memory 220 and the storage device 260 may be configured as at least one of a volatile storage medium and a non-volatile storage medium. For example, the memory 220 may be configured as at least one of a read only memory (ROM) and a random access memory (RAM).

Referring back to FIG. 1 , the communication system 100 includes a plurality of base stations 110-1, 110-2, 110-3, 120-1, and 120-2, a plurality of user equipment ) (130-1, 130-2, 130-3, 130-4, 130-5, 130-6). Each of the first base station 110-1, the second base station 110-2, and the third base station 110-3 may form a macro cell. Each of the fourth base station 120-1 and the fifth base station 120-2 may form a small cell. The fourth base station 120-1, the third terminal 130-3, and the fourth terminal 130-4 may belong to the coverage of the first base station 110-1. The second terminal 130-2, the fourth terminal 130-4, and the fifth terminal 130-5 may belong to the coverage of the second base station 110-2. The fifth base station 120-2, the fourth terminal 130-4, the fifth terminal 130-5, and the sixth terminal 130-6 may belong within the coverage of the third base station 110-3. . The first terminal 130-1 may belong to the coverage of the fourth base station 120-1. The sixth terminal 130-6 may belong to the coverage of the fifth base station 120-2.

Here, each of the plurality of base stations 110-1, 110-2, 110-3, 120-1, 120-2 is a NodeB (NodeB), an advanced NodeB (evolved NodeB), a base transceiver station (BTS), A radio base station, a radio transceiver, an access point, an access node, a road side unit (RSU), a radio remote head (RRH), a transmission point (TP) , a transmission and reception point (TRP), a relay node, and the like. Each of the plurality of terminals 130-1, 130-2, 130-3, 130-4, 130-5, 130-6 is a terminal, an access terminal, a mobile terminal, It may be referred to as a station, a subscriber station, a mobile station, a portable subscriber station, a node, a device, and the like.

A plurality of communication nodes (110-1, 110-2, 110-3, 120-1, 120-2, 130-1, 130-2, 130-3, 130-4, 130-5, 130-6) Each may support cellular (cellular) communication (eg, long term evolution (LTE), LTE-A (advanced), etc. defined in the 3rd generation partnership project (3GPP) standard). Each of the plurality of base stations 110-1, 110-2, 110-3, 120-1, and 120-2 may operate in different frequency bands or may operate in the same frequency band. Each of the plurality of base stations 110-1, 110-2, 110-3, 120-1, and 120-2 may be connected to each other through an ideal backhaul or a non-ideal backhaul, and the ideal backhaul Alternatively, information may be exchanged with each other through a non-ideal backhaul. Each of the plurality of base stations 110-1, 110-2, 110-3, 120-1, and 120-2 may be connected to a core network (not shown) through an ideal backhaul or a non-ideal backhaul. Each of the plurality of base stations 110-1, 110-2, 110-3, 120-1, and 120-2 transmits a signal received from the core network to the corresponding terminals 130-1, 130-2, 130-3, 130 -4, 130-5, 130-6), and the signal received from the corresponding terminal (130-1, 130-2, 130-3, 130-4, 130-5, 130-6) is transmitted to the core network can be sent to

Each of the plurality of base stations 110-1, 110-2, 110-3, 120-1, and 120-2 may support OFDMA-based downlink transmission, and SC-FDMA-based uplink (uplink) transmission. ) can support transmission. In addition, each of the plurality of base stations 110-1, 110-2, 110-3, 120-1, and 120-2 transmits multiple input multiple output (MIMO) (eg, single user (SU)-MIMO, MU (multi user)-MIMO, massive MIMO, etc.), coordinated multipoint (CoMP) transmission, carrier aggregation transmission, transmission in an unlicensed band, device to device, D2D ) communication (or ProSe (proximity services)) may be supported. Here, each of the plurality of terminals 130-1, 130-2, 130-3, 130-4, 130-5, 130-6 is the base station 110-1, 110-2, 110-3, and 120-1. , 120-2) and corresponding operations, and operations supported by the base stations 110-1, 110-2, 110-3, 120-1, and 120-2 may be performed.

For example, the second base station 110-2 may transmit a signal to the fourth terminal 130-4 based on the SU-MIMO method, and the fourth terminal 130-4 may transmit a signal based on the SU-MIMO method. A signal may be received from the second base station 110 - 2 . Alternatively, the second base station 110-2 may transmit a signal to the fourth terminal 130-4 and the fifth terminal 130-5 based on the MU-MIMO scheme, and the fourth terminal 130-4. and each of the fifth terminals 130 - 5 may receive a signal from the second base station 110 - 2 by the MU-MIMO method. Each of the first base station 110-1, the second base station 110-2, and the third base station 110-3 may transmit a signal to the fourth terminal 130-4 based on the CoMP scheme, and the fourth The terminal 130-4 may receive signals from the first base station 110-1, the second base station 110-2, and the third base station 110-3 by the CoMP method. Each of the plurality of base stations 110-1, 110-2, 110-3, 120-1, and 120-2 includes the terminals 130-1, 130-2, 130-3, 130-4, 130-5, 130-6) and a signal may be transmitted/received based on the carrier aggregation method. Each of the first base station 110-1, the second base station 110-2, and the third base station 110-3 coordinates D2D communication between the fourth terminal 130-4 and the fifth terminal 130-5. (coordination), each of the fourth terminal 130-4 and the fifth terminal 130-5 is D2D communication by the respective coordination of the second base station 110-2 and the third base station 110-3 can be performed.

3 is a conceptual diagram illustrating an embodiment of a communication system including a core network.

3, the communication system 300 includes a core network 310, an access network (AN) (eg, a radio access network (RAN)) 320, a data network (DN) 330 and a UE ( user equipment) 340 . The core network 310 includes an access and mobility management function (AMF) 310-1, a user plane function (UPF) 310-2, a session management function (SMF) 310-3, and an authentication server function (AUSF). (310-4), NEF (network exposure function) (310-5), NRF (network repository function) (310-6), PCF (policy control function) (310-7), UDM (user data management) (310) -8), an application function (AF) 310-9, and a network slice selection function (NSSF) 310-10. Here, the NSSF 310-10 may be used to support selection of a network slice. In the embodiments below, the network slice may indicate a network slice instance (NSI) or a network slice subnet instance (NSSI).

The network functions 310-1 to 310-10 constituting the core network 310 may be performed by one or more physical devices. Alternatively, the network functions 310-1 to 310-10 constituting the core network 310 may be implemented as instances or virtual functions executed in a physical device.

The core network 310 may be classified into a control plane and a user plane. The control plane may be classified into a common control plane and a slice specific control plane. AMF 310 - 1 , UPF 310 - 2 , AUSF 310 - 4 , UDM 310 - 8 , and NSSF 310 - 10 may belong to a common control plane. The SMF 310-3, NEF 310-5, NRF 310-6, and PCF 310-7 may belong to a common control plane or a slice-specific control plane. Network functions belonging to a common control plane may be shared by a plurality of NSIs or a plurality of NSSIs. Network functions belonging to a slice specific control plane may be dedicated for a specific NSI or a specific NSSI.

The AMF 310-1 may perform the following functions.

- Termination of RAN CP (control plane) interface (N2)

- NAS (non-access stratum) interface (N1) termination, NAS encryption and integrity protection

- Registration management

- connection management

- Reachability management

- Mobility management

- Lawful intercept of AMF events and interfaces of L1 systems

- Transparent proxy for SM message routing

- access authentication

- access authorization

- SEA (security anchor function)

- SCM (security context management)

Meanwhile, in the communication system 300 , communication between the AMF 310-1 and the NSSF 310-10 may be performed through an Ns interface, and the AMF 310-1 interworks with the NSSF 310-10 to network A slicing-related operation may be performed. For example, NSI or NSSI may be selected based on the operation between the AMF 310-1 and the NSSF 310-10.

When the network slicing technique is applied to the communication system 300 , network resources/functions may be set as one independent network slice according to a required service. Accordingly, the network operator may set a network resource/function specialized for a service or a user as a network slice, and may provide the network slice to a user who has requested the corresponding service. In addition, software defined networking (SDN)/network function virtualization (NFV) technology may be applied to the communication system 300 , and accordingly, network resources/functions may be virtualized.

Next, operating methods of a terminal performing paging in a communication system will be described. Even when a method (eg, transmission or reception of a signal) performed in a first communication node among communication nodes is described, a corresponding second communication node is a method (eg, a method corresponding to the method performed in the first communication node) For example, reception or transmission of a signal) may be performed. That is, when the operation of the terminal is described, the base station corresponding to the terminal may perform the operation corresponding to the operation of the terminal. Conversely, when the operation of the base station is described, the terminal corresponding to the base station may perform the operation corresponding to the operation of the base station.

4 is a flowchart illustrating an embodiment of a method of paging operation of communication nodes.

Referring to FIG. 4 , the communication system of FIG. 4 may be the same as or similar to the communication system of FIG. 1 . The terminal 401 of FIG. 4 may be the communication nodes 130-1, 130-2, 130-3, 130-4, 130-5, and 130-6 of FIG. 1 . The first base station 410 of FIG. 4 may be the communication node 110 - 1 of FIG. 1 , and the second base station 420 of FIG. 4 may be the communication node 110 - 2 of FIG. 1 . The terminal 401 and the base stations 410 and 420 may perform communication based on a communication protocol (eg, a 4G communication protocol, a 5G communication protocol). The first base station 410 to the second base station 420 may belong to the same RNA.

The terminal 401 may include a plurality of universal subscriber identity modules (USIMs). Each USIM may store an international mobile subscriber identity (IMSI) value including different PLMN IDs. For example, the terminal 401 may include a first USIM to which a first IMSI value including the first PLMN ID is assigned and a second USIM to which a second IMSI value including the second PLMN ID is assigned. The first base station 410 to the second base station 420 may belong to the same or different public land mobile networks (PLMNs). For example, the first base station 410 may belong to a first PLMN, and the second base station 420 may belong to a different PLMN (eg, a second PLMN) from the first base station 410 . The first base station 410 may belong to the same PLMN as the first USIM of the terminal 401 , and the second base station 420 may belong to the same PLMN as the second USIM of the terminal 401 .

The terminal 401 may operate in an RRC connected state with the first base station 410 (S401) and may operate in an RRC connected state with the second base station 420 (S402). The terminal 401 in the RRC connected state may obtain information for setting a paging occasion from the RRC connected base stations (eg, the first base station 410 and the second base station 420). . Information for configuring a paging occasion may include information in Table 1.

Referring to Table 1, the paging message is related to a message type (message type) information element (IE), UE paging identity (UE) IE, paging discontinuous reception (DRX) IE, tracking area identity (TAI) Information (eg, TAI List for Paging, TAI list for paging item, etc.) IE, paging priority IE, terminal radio capability for paging (UE radio capability for paging) IE, It may include an assistance data for paging IE and a paging origin IE.

The message type IE may indicate the type of the message. The UE paging identifier IE may be an identifier for identifying a paging target terminal. The base station may allocate the UE paging identifier IE to the terminal 401 in an RRC configuration procedure (or after the RRC configuration procedure). The paging DRX IE may indicate a DRX cycle of the UE 401 . TAI list (TAI list) IE may indicate a TA to broadcast a paging message (broadcast). The TAI may be an identifier for uniquely identifying the TA. The paging priority IE may indicate the paging priority of the terminal 401 . The terminal radio capability IE for paging may include radio capability information of the paging target terminal.

The UE paging ID may be an identifier for identifying a paged terminal. The UE paging ID may include information on at least one of IMSI and S-TMSI (system architecture evolution (SAE) temporary mobile subscriber identity). The S-TMSI may be an identifier capable of uniquely identifying a UE in one X2 control plane. The S-TMSI may include the information in Table 2.

The AMF set ID may indicate the AMF set to which the AMF of the communication system belongs, and the AMF pointer may indicate one AMF among the AMF sets. 5G-TMSI may indicate the core network to which the AMF of the wireless communication network belongs. The base station may allocate 5G-TMSI to the terminal 401 in the RRC setup procedure (or after the RRC setup procedure). That is, the terminal 401 may set the 5G-TMSI in the RRC setup procedure with the first base station 410 (or after the RRC setup procedure), and in the RRC setup procedure with the second base station 420 (or, After the RRC setting procedure), a separate 5G-TMSI can be set.

When radio link failure (RLF) occurs between the terminal 401 and the base station, the connection is disconnected, or the terminal does not receive traffic from the base station for a preset time, the terminal 401 performs RRC in the RRC connection state. It may transition to an inactive (RRC inactive) state or an RRC idle state (S403). In S403, the terminal 401 may transition the connection state with the first base station 410 to the RRC deactivation state (or RRC idle state), and change the connection state with the second base station to the RRC deactivation state (or RRC idle state) can be transferred to

The first base station 410 may transmit a paging message to the terminal 401 (S404). And the second base station 420 may transmit a paging message to the terminal 401 (S408). Each of the base stations that will transmit data to the terminal 401 (eg, the first base station 410 and/or the second base station 420 ) may transmit a paging message to the terminal 401 . Each of the base stations (eg, the first base station 410 and/or the second base station 420) may transmit a physical downlink control channel (PDCCH) including downlink control information (DCI), and is indicated by the DCI. A paging message may be transmitted through a physical downlink shared channel (PDSCH). The paging message transmitted by each of the base stations of the communication system (eg, the first base station 410 to the second base station 420) may include information corresponding to Tables 1 and 2 and/or identifier information of the terminal. can

The terminal 401 that has performed the state transition operation in S403 may monitor the paging messages from the first base station 410 and the second base station 420 . The terminal 401 may search for different paging occasions configured with the first base station 410 and the second base station 420 . The UE 410 may search for a PDCCH by monitoring a paging occasion every DRX cycle. The PDCCH may indicate resource information of the PDSCH for transmitting the paging message. The terminal 401 may search for a paging message for each PLMN. For example, the terminal 401 may search for a paging message from the first base station 410 having the first PLMN based on the RRC configuration information obtained from the first base station 410 in the RRC connection state. In addition, the terminal 401 may search for a paging message from the second base station 420 having the second PLMN based on the RRC configuration information obtained from the second base station 420 in the RRC connection state. As a result of the paging occasion search, the terminal 401 may receive a PDCCH, and may receive a paging message from the first base station 410 and/or the second base station 420 through the PDSCH resource indicated by the PDCCH. . According to the configuration information in the RRC connection state, the paging occasion with the first base station 410 may be different from the paging occasion with the second base station 420 . And, according to the configuration information in the RRC connection state, the frequency of the paging message of the first base station 410 may be different from the frequency of the paging message of the second base station 420 . However, when the paging message of the first base station 410 and the paging message of the second base station 420 collide, the terminal 401 may not be able to perform paging.

According to an embodiment of the present invention, the paging message transmitted by each of the base stations (eg, the first base station 410 and the second base station 420 ) of the communication system may further include PLMN information. Specifically, the paging message may include a UE paging ID, and the UE paging ID may include the information in Table 3.

Referring to Table 3, the UE paging ID includes the S-TMSI, and may further include a PLMN ID indicating the PLMN of the base station. Accordingly, the terminal may identify different paging messages from different base stations (eg, the first base station 410 and the second base station 420 ), respectively. The terminal 401 may receive a paging message from the first base station 410 (S404). Accordingly, the terminal 401 may transmit an RRC resume request message to the first base station 410 belonging to the PLMN indicated by the PLMN ID of the UE paging ID IE (S405). When the first base station 410 receives the RRC resume request message from the terminal 401, the first base station 410 may transmit an RRC resume message to the terminal 401 (S406). Upon receiving the RRC resume message from the first base station 410, the terminal 401 may transmit an RRC resume complete message to the first base station 410 (S407). The terminal 401 may return to an RRC connected state with the first base station 410 .

The terminal 401 may receive a paging message from the second base station 420 (S408). Accordingly, the terminal 401 may transmit an RRC resume request message to the second base station 420 having the PLMN of the UE paging ID IE (S409). When the second base station 420 receives the RRC resume request message from the terminal 401, the second base station 420 may transmit an RRC resume message to the terminal 401 (S410). Upon receiving the RRC resume message from the second base station 420, the terminal 401 may transmit an RRC resume complete message to the second base station 420 (S411). The terminal 401 may return to the RRC connected state with the second base station 410 .

According to another embodiment of the present invention, DCI transmitted by each of the base stations (eg, the first base station and/or the second base station) may include a cyclic redundancy check (CRC). Each of the base stations (eg, the first base station and/or the second base station) may scrambling the CRC of the DCI by a paging-RNTI (P-RNTI). The P-RNTI may be independently configured for each PLMN. For example, the P-RNTI of the first base station 410 may be set to a value different from the P-RNTI of the second base station 420 .

The terminal 401 may receive a paging message from the first base station 410 based on the P-RNTI information with the first base station 410 (S404). Accordingly, the terminal 401 may transmit an RRC resume request message to the first base station 410 determined based on the P-RNTI information (S405). When the first base station 410 receives the RRC resume request message from the terminal 401, the first base station 410 may transmit an RRC resume message to the terminal 401 (S406). Upon receiving the RRC resume message from the first base station 410, the terminal 401 may transmit an RRC resume complete message to the first base station 410 (S407). The terminal 401 may return to the RRC connection state with the first base station 410 .

The terminal 401 may receive a paging message from the second base station 420 based on the P-RNTI information with the second base station 420 (S408). Accordingly, the terminal 401 may transmit an RRC resume request message to the second base station 420 determined based on the P-RNTI information (S409). When the second base station 420 receives the RRC resume request message from the terminal 401, the second base station 420 may transmit an RRC resume message to the terminal 401 (S410). Upon receiving the RRC resume message from the second base station 420, the terminal 401 may transmit an RRC resume complete message to the second base station 420 (S411). The terminal 401 may return to the RRC connection state with the second base station 410 .

The methods according to the present invention may be implemented in the form of program instructions that can be executed by various computer means and recorded in a computer-readable medium. The computer-readable medium may include program instructions, data files, data structures, and the like, alone or in combination. The program instructions recorded on the computer-readable medium may be specially designed and configured for the present invention, or may be known and available to those skilled in the art of computer software.

Examples of computer-readable media include hardware devices specially configured to store and carry out program instructions, such as ROM, RAM, flash memory, and the like. Examples of program instructions include not only machine language codes such as those generated by a compiler, but also high-level language codes that can be executed by a computer using an interpreter or the like. The hardware device described above may be configured to operate as at least one software module to perform the operations of the present invention, and vice versa.

Although it has been described with reference to the above embodiments, it will be understood by those skilled in the art that various modifications and changes can be made to the present invention without departing from the spirit and scope of the present invention as set forth in the claims below. will be able

Claims (1)

A method of operating a terminal in a wireless communication system, comprising:
establishing a radio resource control (RRC) connection with the first base station (RRC configuration);
establishing an RRC connection with a second base station;
Transitioning the RRC connection state with the first base station and the second base station to one of a radio resource control (RRC) inactive state and an RRC idle state;
discovering a paging message by monitoring a first paging occasion configured with the first base station and a second paging occasion configured with the second base station;
receiving a first paging message from the first base station through a first paging occasion as a result of searching for the paging message; and
Including the step of performing an RRC reconfiguration (RRC reconfiguration) procedure with the first base station, the operating method of the terminal.

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