Method and apparatus for reselecting a cell in a wireless communication system

Abstract

A method performed by a terminal in a wireless communication system, comprising: sending capability information of the terminal to a first cell, the capability information of the terminal including information on whether the terminal supports multiple cell reselection priorities (CRPs); receiving a radio resource control (RRC) connection release message from a first EUTRAN cell based on the capability information of the terminal, the RRC connection release message including an alternative CRP indication parameter indicating application of CRP broadcast in system information; switching to an RRC idle mode or an RRC inactive mode based on the RRC connection release message, and residing on a second cell; receiving system information from the second cell; and determining whether to apply a first CRP for RAT inter-frequency or a second CRP for at least one EUTRAN frequency based on the system information.

Description

Technical Field

[0001] The present disclosure relates to a method and apparatus for reselecting a cell in a wireless communication system. Background Art

[0002] In order to meet the increasing demand for wireless data services since the commercialization of the fourth generation (4G) communication system, efforts have been made to develop a quasi-fifth generation (5G) communication system or a 5G communication system. This is also the reason why the "5G communication system" or "quasi-5G communication system" is called a "super 4G network communication system" or a "post-long term evolution (LTE) system". In order to achieve high data rates, the 5G communication system under development is implemented in an ultra-high frequency band (millimeter wave (mmwave)), such as a frequency band of 60 GHz. In order to reduce the path loss of radio waves in such an ultra-high frequency band and increase the transmission distance of radio waves in the 5G communication system, various technologies have been discussed and are being studied, such as beamforming, massive multiple input and multiple output (massive MIMO), full-dimensional MIMO (FD-MIMO), array antennas, analog beamforming, and massive antennas. In order to improve the system network for 5G communication system, various technologies have been developed, such as evolved small cells, advanced small cells, cloud radio access network (Cloud-RAN), ultra-dense networks, device-to-device (D2D) communication, wireless backhaul, mobile networks, cooperative communication, coordinated multi-point (CoMP) and interference cancellation. In addition, for 5G communication system, other technologies have been developed, such as hybrid frequency shift keying (FSK) and quadrature amplitude modulation (QAM) (FQAM) and sliding window superposition coding (SWSC) as advanced coding modulation (ACM) schemes, and filter bank multi-carrier (FBMC), non-orthogonal multiple access (NOMA) and sparse coded multiple access (SCMA) as advanced access schemes.

[0003] The Internet has evolved from a human-centered connectivity network where humans create and consume information to the Internet of Things (IOT), where distributed components such as objects exchange information with each other to process information. Internet of Everything (IoE) technology is emerging, which combines IoT technology with, for example, big data processing technology through connection with a cloud server. In order to realize IoT, various technical components such as sensing technology, wired / wireless communication and network infrastructure, service interface technology, security technology, etc. are required. In recent years, technologies including sensor networks for connecting objects, machine-to-machine (M2M) communication, machine type communication (MTC), etc. have been studied. In the IoT environment, smart Internet technology (IT) services can be provided to collect and analyze data obtained from objects connected to each other, thereby creating new value for human life. Since existing information technology (IT) technologies and various industries are integrated and combined with each other, IT can be applied to various fields, such as smart homes, smart buildings, smart cities, smart cars or connected cars, smart grids, health care, smart appliances, high-quality medical services, etc.

[0004] Various attempts are being made to apply 5G communication systems to IoT networks. For example, technologies related to sensor networks, M2M communications, MTC, etc. are implemented by using 5G communication technologies including beamforming, MIMO, array antennas, etc. The application of cloud RAN as the above-mentioned big data processing technology can be an example that can be considered as a fusion between 5G technology and IoT technology.

[0005] As described above, due to the development of wireless communication systems, various services can be provided, and thus a method for easily providing such services is required. Summary of the invention

[0006] Provided are an apparatus and method for efficiently providing a service in a wireless communication system. BRIEF DESCRIPTION OF THE DRAWINGS

[0007] For a more complete understanding of the present disclosure and its advantages, reference is now made to the following description taken in conjunction with the accompanying drawings, wherein like reference numerals represent like parts:

[0008] Figure 1A is a diagram showing a structure of a Long Term Evolution (LTE) system according to an embodiment of the present disclosure;

[0009] Figure 1B is a diagram showing a radio protocol structure in an LTE system according to an embodiment of the present disclosure;

[0010] Figure 1C is a diagram showing a structure of a next generation mobile communication system according to an embodiment of the present disclosure;

[0011] Figure 1Dis a diagram showing a wireless protocol structure of a next generation mobile communication system according to an embodiment of the present disclosure;

[0012] Figure 1E A diagram for describing a process of performing cell reselection by a terminal in a radio resource control (RRC) inactive mode RRC_INACTIVE or an RRC idle mode RRC_IDLE in an LTE system according to an embodiment of the present disclosure;

[0013] Figure 1F A diagram for describing a process of performing cell reselection by a terminal in an RRC inactive mode RRC_INACTIVE or an RRC idle mode RRC_IDLE in a next generation mobile communication system according to an embodiment of the present disclosure;

[0014] Figure 1G A diagram for describing a process of performing cell reselection by a terminal in an RRC inactive mode RRC_INACTIVE or an RRC idle mode RRC_IDLE in a next generation mobile communication system according to an embodiment of the present disclosure;

[0015] Figure 1H A diagram for describing a process of performing cell reselection by a terminal in an RRC inactive mode RRC_INACTIVE or an RRC idle mode RRC_IDLE in a next generation mobile communication system according to an embodiment of the present disclosure;

[0016] Fig. 1I A diagram for describing a process of performing cell reselection by a terminal in an RRC inactive mode RRC_INACTIVE or an RRC idle mode RRC_IDLE in a next generation mobile communication system according to an embodiment of the present disclosure;

[0017] Figure 1J is a diagram for describing a process of performing cell reselection by a terminal in an RRC inactive mode RRC_INACTIVE or an RRC idle mode RRC_IDLE in a next generation mobile system according to an embodiment of the present disclosure;

[0018] Figure 1K is a block diagram showing an internal structure of a terminal according to an embodiment of the present disclosure; and

[0019] Figure 1L is a block diagram showing a configuration of a new radio (NR) base station according to an embodiment of the present disclosure.

[0020] Best Mode for Carrying Out the Invention

[0021] Provided are an apparatus and method for efficiently providing a service in a wireless communication system.

[0022] Additional aspects will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the embodiments presented in the disclosure.

[0023] According to an embodiment of the present disclosure, a method performed by a terminal in a wireless communication system includes: sending capability information of the terminal to a first Evolved Universal Mobile Telecommunications System (UMTS) Terrestrial Radio Access Network (EUTRAN) cell, the capability information of the terminal including information about whether the terminal supports multiple cell reselection priorities (CRPs); based on the capability information of the terminal, receiving a radio resource control (RRC) connection release message from the first EUTRAN cell, the RRC connection release message including an alternative CRP indication parameter indicating application of CRP broadcast in system information; based on the RRC connection release message, switching to an RRC idle mode or an RRC inactive mode, and residing on a second EUTRAN cell; receiving system information from the second EUTRAN cell; and based on the system information, determining whether to apply a first CRP for RAT heterofrequency or a second CRP for at least one EUTRAN frequency.

[0024] The method may further include: in a case where the RRC connection release message includes a timer value, starting a timer based on the timer value.

[0025] The system information may be included in system information block (SIB) 3 or SIB5.

[0026] The SIB3 may include information about a second CRP of a serving frequency associated with the second EUTRAN cell, and the second CRP of the serving frequency may be determined based on at least one of a cellReselectionPriority value or a cellReselectionSubpriority value.

[0027] SIB5 may include information about the second CRP of the EUTRAN inter-frequency.

[0028] According to an embodiment of the present disclosure, a terminal in a wireless communication system includes: a transceiver; and at least one processor connected to the transceiver and configured to: send capability information of the terminal to a first Evolved Universal Mobile Telecommunications System (UMTS) Terrestrial Radio Access Network (EUTRAN) cell, the capability information of the terminal including information about whether the terminal supports multiple cell reselection priorities (CRPs); based on the capability information of the terminal, receive a radio resource control (RRC) connection release message from the first EUTRAN cell, the RRC connection release message including an alternative CRP indication parameter indicating application of CRP broadcast in system information; based on the RRC connection release message, switch to RRC idle mode or RRC inactive mode, and reside on a second EUTRAN cell; receive system information from the second EUTRAN cell; and based on the system information, determine whether to apply a first CRP for RAT heterofrequency or a second CRP for at least one EUTRAN frequency.

[0029] The at least one processor may be further configured to start a timer if the RRC connection release message includes a timer value.

[0030] The system information may be included in system information block (SIB) 3 or SIB5.

[0031] SIB3 may include information of a second CRP of a serving frequency associated with the second EUTRAN cell, and the second CRP of the serving frequency may be determined based on at least one of a cellReselectionPriority value or a cellReselectionSubpriority value.

[0032] SIB5 may include information about the second CRP of the EUTRAN inter-frequency.

[0033] According to an embodiment of the present disclosure, a method performed by a base station associated with a first Evolved Universal Mobile Telecommunications System (UMTS) Terrestrial Radio Access Network (EUTRAN) cell in a wireless communication system includes: receiving capability information of a terminal from a terminal, the capability information of the terminal including information about whether the terminal supports multiple cell reselection priorities (CRPs); and based on the capability information of the terminal, sending a radio resource control (RRC) connection release message to the terminal, the RRC connection release message including an alternative CRP indication parameter indicating application of CRP broadcast in system information; and wherein the terminal switches to an RRC idle mode or an RRC inactive mode based on the RRC connection release message, resides on a second EUTRAN cell, receives system information from the second EUTRAN cell, and determines whether to apply a first CRP for RAT heterofrequency or a second CRP for at least one EUTRAN frequency based on the system information.

[0034] In case the RRC connection release message includes the timer value, the terminal may start the timer based on the timer value.

[0035] The system information may be included in system information block (SIB) 3 or SIB5.

[0036] The SIB3 may include information of a second CRP of a serving frequency associated with the second EUTRAN cell, and the second CRP of the serving frequency may be determined based on at least one of a cellReselectionPriority value or a cellReselectionSubpriority value.

[0037] SIB5 may include information about the second CRP of the EUTRAN inter-frequency.

[0038] According to an embodiment of the present disclosure, a base station associated with a first Evolved Universal Mobile Telecommunications System (UMTS) Terrestrial Radio Access Network (EUTRAN) cell in a wireless communication system includes: a transceiver; and at least one processor, connected to the transceiver and configured to: receive capability information of a terminal from a terminal, the capability information of the terminal including information about whether the terminal supports multiple cell reselection priorities (CRPs); and based on the capability information of the terminal, send a radio resource control (RRC) connection release message to the terminal, the RRC connection release message including an alternative CRP indication parameter indicating application of CRP broadcast in system information; wherein the terminal switches to an RRC idle mode or an RRC inactive mode based on the RRC connection release message, resides on a second EUTRAN cell, receives system information from the second EUTRAN cell, and determines whether to apply a first CRP for RAT heterofrequency or a second CRP for at least one EUTRAN frequency based on the system information.

[0039] In case the RRC connection release message includes the timer value, the terminal may start the timer based on the timer value.

[0040] The system information may be included in system information block (SIB) 3 or SIB5.

[0041] SIB3 may include information of a second CRP of a serving frequency associated with the second EUTRAN cell, and the second CRP of the serving frequency is determined based on at least one of a cellReselectionPriority value or a cellReselectionSubpriority value.

[0042] SIB5 may include information about the second CRP of the EUTRAN inter-frequency.

[0043] Before proceeding to the following detailed description, it may be beneficial to set forth definitions of certain words and phrases used throughout the patent document. The terms "include" and "comprise" and their derivatives are intended to include without limitation; the term "or" is inclusive, meaning and / or; the phrase "associated with" and its derivatives may mean include, included within, interconnected with, include, included within, connected to or connected with, connected to or connected with, communicate with, collaborate with, interweave, parallel, close to, bound to or bound with, have, have the characteristics of, etc.; and the term "controller" refers to any device, system, or part thereof that controls at least one operation. Such a device may be implemented as hardware, firmware, or software, or some combination of at least two thereof. It should be noted that the functionality associated with any particular controller may be centralized or distributed, whether local or remote.

[0044] In addition, the various functions described below can be implemented or supported by one or more computer programs, each of which is formed by a computer-readable program code and implemented in a computer-readable medium. The terms "application" and "program" refer to one or more computer programs, software components, instruction sets, processes, functions, objects, classes, examples, related data or parts thereof that are suitable for implementation with suitable computer-readable program codes. The phrase "computer-readable program code" includes any type of computer code, including source code, object code and executable code. The phrase "computer-readable medium" includes any type of medium that can be accessed by a computer, such as a read-only memory (ROM), a random access memory (RAM), a hard drive, a compact disc (CD), a digital video disc (DVD) or any other type of memory. "Non-transitory" computer-readable medium excludes wired, wireless, optical or other communication links that transmit instantaneous electrical signals or other instantaneous signals. Non-transitory computer-readable media include media that can permanently store data, and media that can store data and then rewrite data, such as rewritable optical discs or erasable storage devices.

[0045] Definitions for certain words and phrases are provided throughout this patent document, those skilled in the art should understand that in many, if not most instances, such definitions apply to prior, as well as future uses of such defined words and phrases.

[0046] [Invention Mode]

[0047] Discussed below Figures 1A to 1L The various embodiments used to describe the principles of the present disclosure in this patent document are merely exemplary and should not be interpreted in any way as limiting the scope of the present disclosure. Those skilled in the art will appreciate that the principles of the present invention can be implemented in any appropriately arranged system or device.

[0048] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. When describing the present disclosure, when it is considered that the relevant well-known functions or configurations may unnecessarily obscure the essence of the present disclosure, the detailed description of the relevant well-known functions or configurations may be omitted. In addition, the terms used below are defined in consideration of the functions in the present disclosure, and may have different meanings depending on the intentions of the user or operator, conventions, etc. Therefore, the terms should be defined based on the descriptions throughout the specification.

[0049] The advantages and features of the present disclosure and the methods for achieving these advantages and features will become apparent with reference to the embodiments of the present disclosure described in detail below in conjunction with the accompanying drawings. However, the present disclosure can be implemented in many different forms and should not be construed as being limited to the embodiments described herein; on the contrary, these embodiments of the present disclosure are provided so that the present disclosure will be thorough and complete and fully convey the concepts of the present disclosure to those skilled in the art. The scope of the present disclosure is limited only in the claims. Throughout the specification, the same reference numerals or characters represent the same elements.

[0050] Throughout the disclosure, the expression "at least one of a, b, or c" means only a, only b, only c, both a and b, both a and c, both b and c, all of a, b, and c, or variations thereof.

[0051] Examples of the terminal may include a User Equipment (UE), a Mobile Station (MS), a cellular phone, a smart phone, a computer, a multimedia system capable of performing a communication function, and the like.

[0052] In this disclosure, a controller may also be referred to as a processor.

[0053] Throughout the specification, a layer (or a layer device) may also be referred to as an entity.

[0054] It will be understood that each frame shown in the flow chart and the combination of frames shown in the flow chart can be implemented by computer program instructions. Computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer or other programmable data processing device, so that the instructions executed by the processor of the computer or other programmable data processing device generate a device for performing the function specified in the flow chart frame. These computer program instructions can also be stored in a computer-usable or computer-readable memory, which can guide the computer or other programmable data processing device to operate in a particular manner, so that the instructions stored in the computer-usable or computer-readable memory generate a product including an instruction device for performing the function specified in the flow chart frame. These computer program instructions can also be loaded onto a computer or other programmable data processing device, causing a series of operations for generating a computer-implemented process to be performed on a computer or other programmable device, so that the instructions executed on the computer or other programmable data processing device provide operating steps for implementing the function specified in the flow chart frame.

[0055] In addition, each frame can represent a module, a fragment or a partial code, which includes one or more executable instructions for implementing a specified logical function. It should also be noted that in some optional embodiments, the functions shown in the frame may not occur in this order. For example, the two frames that are actually continuously shown can be executed substantially simultaneously, or these frames can sometimes be executed in reverse order according to the functions involved.

[0056] As used herein, the term "unit" or "device" represents a software element or hardware element such as a field programmable gate array (FPGA) or an application specific integrated circuit (ASIC), and performs a certain task. However, the term "unit" or "device" is not limited to software or hardware. The term "unit" or "device" can be configured to be included in an addressable storage medium or configured to rebuild one or more processors. Therefore, as an example, the term "unit" or "device" may include object-oriented software components, class components and task components, as well as processes, functions, attributes, procedures, subroutines, program code fragments, drivers, firmware, microcodes, circuits, data, databases, data structures, tables, arrays and variables. The functions provided in the components and "units" or "devices" can be combined into fewer components and "units" or "devices", or can be further separated into additional components and "units" or "devices". In addition, the components and "units" or "devices" can be implemented as one or more central processing units (CPUs) in an operating device or a secure multimedia card. In addition, the "unit" or "device" may include at least one processor.

[0057] When describing the present disclosure, when it is considered that the relevant well-known functions or configurations may unnecessarily obscure the essence of the present disclosure, the detailed description of the relevant well-known functions or configurations may be omitted. Hereinafter, embodiments of the present disclosure will be described with reference to the accompanying drawings.

[0058] In the following description, terms used to identify access nodes, terms about network entities, terms related to messages, terms related to interfaces between network objects, and terms about various identification information are examples provided for ease of description. However, the present disclosure is not limited to the following terms, and other terms with equivalent technical meanings may also be used.

[0059] In the following, for the convenience of description, the terms and names defined in the 3rd Generation Partnership Project Long Term Evolution (3GPP LTE) specifications are used in the present disclosure. However, the present disclosure is not limited to these terms and names, but may also be applicable to systems that comply with other specifications. In particular, the present disclosure may be applicable to 3GPP New Radio (NR, the fifth generation mobile communication standard). In the present disclosure, for the convenience of description, "eNB" may be used interchangeably with "gNB". That is, a base station described as "eNB" may represent a "gNB". In addition, the term "terminal" may refer not only to a mobile phone, a narrowband Internet of Things (NB-IoT) device, or a sensor, but also to other wireless communication devices.

[0060] Hereinafter, a base station refers to an entity that allocates resources to a terminal, and may be at least one of a gNodeB, an eNodeB, a NodeB, a base station (BS), a wireless access unit, a base station controller, or a node on a network. Examples of terminals may include user equipment (UE), a mobile station (MS), a cellular phone, a smart phone, a computer, a multimedia system capable of performing a communication function, etc. However, the terminal is not limited to the above examples.

[0061] Figure 1A is a diagram showing a structure of an LTE system according to an embodiment of the present disclosure.

[0062] refer to Figure 1A , the radio access network of the LTE system may include next-generation base stations (evolved node B (ENB) (hereinafter referred to as "ENB", "Node B" or "base station")) 1a-05, 1a-10, 1a-15 and 1a-20; mobility management entity (MME) 1a-25 and serving gateway (S-GW) 1a-30. User equipment (hereinafter referred to as "UE" or "terminal") 1a-35 can access external networks via ENB 1a-05, 1a-20 and S-GW 1a-30.

[0063] refer to Figure 1A , the ENB 1a-05 through 1a-20 may correspond to an existing Node B of a Universal Mobile Telecommunications System (UMTS). The ENB may be connected to the UE 1a-35 via a wireless channel and may perform more complex functions than an existing Node B. In an LTE system, all user service data including real-time services such as Voice over Internet Protocol (VoIP) may be provided through a shared channel. Therefore, a device that collects the status information of the UE (e.g., buffer status, available transmit power, channel status, etc.) and schedules the status information is required, and it may be assumed that the ENB 1a-05 through 1a-20 has such a function. One ENB typically controls multiple cells. For example, in an LTE system, in order to achieve a data rate of 100 Mbps, orthogonal frequency division multiplexing (OFDM) may be used as a radio access technology (RAT) on a bandwidth of, for example, 20 MHz. In addition, an adaptive modulation and coding (AMC) scheme that determines a modulation scheme and a channel code rate according to the channel state of the terminal may be applied. The S-GW 1a-30 is a device that provides a data bearer, and can generate or remove a data bearer under the control of the MME 1a-25. It is assumed that the MME is a device that has not only a mobility management function with respect to a terminal but also various control functions, and can be connected to a plurality of base stations.

[0064] Figure 1B is a diagram showing a radio protocol structure of an LTE system according to an embodiment of the present disclosure.

[0065] refer to Figure 1B In each of the terminal and the ENB, the wireless protocol structure of the LTE system may include a packet data convergence protocol (PDCP) 1b-05 / 1b-40, a radio link control (RLC) 1b-10 / 1b-35, and a medium access control (MAC) 1b-15 / 1b-30, and a physical layer 1b-20 / 1b-25. The PDCP layer may be responsible for operations such as IP header compression / decompression. The main functions of the PDCP may be summarized as follows.

[0066] -Header compression and decompression: Robust Header Compression Only (ROHC)

[0067] -User data transmission

[0068] - In-sequence delivery of upper layer packet data units (PDUs) during PDCP re-establishment procedure for RLC Acknowledged Mode (AM)

[0069] - For decentralized bearers in Dual Connectivity (DC) (supporting RLC AM only): PDCP PDU routing for transmission, and PDCP PDU reordering for reception

[0070] - Duplicate detection of lower layer service data units (SDUs) during PDCP re-establishment for RLC AM

[0071] - For distributed bearers in DC, retransmit PDCP SDUs at handover; and for RLC AM, retransmit PDCP PDUs during PDCP data recovery procedure

[0072] -Encryption and decryption

[0073] - Timer-based SDU discard in uplink

[0074] RLC 1b-10 or 1b-35 may reconfigure PDCP PDU to an appropriate size and perform an automatic repeat request (ARQ) operation, etc. The main functions of RLC can be summarized as follows.

[0075] -Upper layer PDU transmission

[0076] -ARQ (error correction through ARQ (only for AM data transmission))

[0077] - Concatenation, segmentation and reassembly of RLC SDUs (only for negative acknowledgement mode (UM) and AM data transmission)

[0078] - Re-segmentation of RLC data PDU (for AM data transmission only)

[0079] - Reordering of RLC data PDUs (only for UM and AM data transmission)

[0080] - Duplicate detection (for UM and AM data transmission only)

[0081] -Protocol error detection (for AM data transmission only)

[0082] -RLC SDU discard (only for UM and AM data transmission)

[0083] -RLC reconstruction

[0084] MAC 1b-15 or 1b-30 is connected to several RLC layers configured in the terminal, and can multiplex RLC PDUs into MAC PDUs and demultiplex the RLC PDUs from MAC PDUs. The main functions of MAC can be summarized as follows.

[0085] - Mapping between logical channels and transport channels

[0086] - Multiplex MAC SDUs belonging to one or different logical channels into a transport block (TB) delivered to the physical layer via a transport channel, or demultiplex the MAC SDUs from a transport block delivered from the physical layer via a transport channel

[0087] -Dispatch information report

[0088] - Hybrid ARQ (HARQ) (error correction via HARQ)

[0089] - Priority handling between logical channels of a UE

[0090] - Priority handling between dynamically scheduled UEs

[0091] -Multimedia Broadcast Multicast Service (MBMS) service identification

[0092] -Transmission format selection

[0093] -filling

[0094] The physical (PHY) layer 1b-20 or 1b-25 can encode and modulate the upper layer data channel into OFDM symbols and send the OFDM symbols through the wireless channel; or can demodulate and channel-decode the OFDM symbols received through the wireless channel, and transmit the demodulated OFDM symbols and the channel-decoded OFDM symbols to the upper layer.

[0095] Figure 1C is a diagram showing a structure of a next generation mobile communication system according to an embodiment of the present disclosure.

[0096] refer to Figure 1C, the radio access network of the next generation mobile communication system (hereinafter referred to as "NR" or 5g) may include a next generation base station (new radio node, hereinafter referred to as "NR gNB" or "NR base station") 1c-10 and a new radio core network (NR CN) 1c-05. The new radio user equipment (hereinafter referred to as "NR UE" or "terminal") 1c-15 can access the external network via the NR gNB 1c-10 and the NR CN 1c-05.

[0097] exist Figure 1C In the present invention, NR gNB 1c-10 may correspond to an evolved Node B (eNB) in an existing LTE system. NR gNB1c-10 is connected to NR UE 1c-15 via a wireless channel and may provide services far superior to those of the existing Node B. In the next generation mobile communication system, all user services may be served through a shared channel. Therefore, a device that collects the status information of the UE (e.g., buffer status, available transmit power, channel status, etc.) and schedules the status information is required, and it may be assumed that NR gNB 1c-10 has such a function. One NR gNB 1c-10 may control multiple cells. In the next generation mobile communication system, in order to achieve higher speed data transmission than the current LTE, a bandwidth larger than the current maximum bandwidth may be applied. In addition, by using OFDM as the RAT, beamforming technology may also be linked to it. In addition, an AMC scheme that determines the modulation scheme and channel code rate according to the channel status of the terminal may be applied. NR CN 1c-05 may perform functions such as mobility support, bearer configuration, or quality of service (QoS) configuration. It is assumed that NR CN1c-05 is a device that has not only a mobility management function for a terminal but also various control functions, and can be connected to multiple base stations. In addition, the next-generation mobile communication system can also be linked to the existing LTE system, and NR CN 1c-05 can be connected to MME 1c-25 via a network interface. MME 1c-25 can be connected to eNB1c-30 which is an existing base station.

[0098] Figure 1D is a diagram showing a wireless protocol structure of a next generation mobile communication system according to an embodiment of the present disclosure.

[0099] refer to Figure 1D , in each of the terminal and the NR base station, the radio protocol of the next-generation mobile communication system consists of NR Service Data Adaptation Protocol (SDAP) 1d-01 / 1d-45, NR PDCP 1d-05 / 1d-40, NR RLC 1d-10 / 1d-35, NRMAC 1d-15 / 1d-30 and NR PHY layer 1d-20 / 1d-25.

[0100] The main functions of NR SDAP 1d-01 or 1d-45 may include some of the following functions.

[0101] -User plane data transmission

[0102] - Mapping between QoS flows and data radio bearers (DRBs) for downlink (DL) and uplink (UL)

[0103] -Mark QoS flow ID in DL and UL packets

[0104] - UL SDAP PDU to DRB mapping reflects QoS flow

[0105] For the SDAP layer, the terminal can be configured via a radio resource control (RRC) message to use the header of the SDAP layer or to use the SDAP layer function of each PDCP layer, each bearer, or each logical channel. When the SDAP header is configured, the terminal can directly update or reconfigure the mapping information of the QoS flow and the data bearer about UL and DL by using a 1-bit indicator of the non-access layer (NAS) reflecting the QoS configuration and a 1-bit indicator of the access layer (AS) reflecting the QoS. The SDAP header may include QoS flow ID information indicating the QoS. The QoS information can be used as data processing priority information or scheduling information, etc. to appropriately support the service.

[0106] The main functions of NR PDCP 1d-05 or 1d-40 may include some of the following functions.

[0107] -Header compression and decompression: ROHC only

[0108] -User data transmission

[0109] - In-sequence delivery of upper layer PDUs

[0110] - Out-of-order delivery of upper layer PDUs

[0111] - Reordering of PDCP PDUs for reception

[0112] - Duplicate detection of lower layer SDU

[0113] -Retransmission of PDCP SDU

[0114] -Encryption and decryption

[0115] - Timer-based SDU discard in uplink

[0116] In the above description, the reordering function of the NR PDCP entity 1d-05 or 1d-40 may indicate a function of reordering PDCP PDUs received in a lower layer in sequence based on a PDCP sequence number (SN). The reordering function of the NR PDCP entity 1d-05 or 1d-40 may include: a function of delivering data to an upper layer in a reordered order, a function of directly delivering data without considering the order, a function of reordering and recording lost PDCP PDUs, a function of reporting the status of lost PDCP PDUs to a transmitting end, or a function of requesting retransmission of lost PDCP PDUs.

[0117] The main functions of NR RLC 1d-10 or 1d-35 may include some of the following functions.

[0118] -Transmission of upper layer PDU

[0119] - In-sequence delivery of upper layer PDUs

[0120] - Out-of-order delivery of upper layer PDUs

[0121] -ARQ (error correction through ARQ)

[0122] - Concatenation, segmentation and reassembly of RLC SDU

[0123] - Re-segmentation of RLC data PDUs

[0124] - Reordering of RLC data PDUs

[0125] - Duplicate detection

[0126] -Protocol error detection

[0127] -RLC SDU discarded

[0128] -RLC reconstruction

[0129] In the above description, the in-sequence delivery function of the NR RLC entity may indicate a function of delivering the RLC SDU received from the lower layer to the upper layer in sequence. When multiple RLC SDUs originating from a single RLC SDU segment are received, the in-sequence delivery function of the NR RLC entity may include a function of reassembling the RLC SDUs and transmitting the reassembled RLC SDUs. The in-sequence delivery function of the NR RLC entity may include a function of reordering the received RLC PDUs based on the RLC SN or PDCP SN. In addition, the in-sequence delivery function of the NR RLC entity 1d-10 or 1d-35 may include a function of reordering and recording lost RLC PDUs, a function of reporting the status of lost RLC PDUs to the transmitter, or a function of requesting retransmission of lost RLC PDUs. When there is a lost RLC SDU, the in-sequence delivery function of the NR RLC entity 1d-10 or 1d-35 may include a function of delivering only the RLC SDUs before the lost RLC SDU to the upper layer in sequence. In addition, even if there is a lost RLC SDU when a certain timer has expired, the in-sequence delivery function of the NR RLC entity 1d-10 or 1d-35 may include a function of delivering all RLC SDUs received before the timer is started to the upper layer in sequence. In addition, even if there is a lost RLC SDU when a certain timer has expired, the in-sequence delivery function of the NR RLC entity 1d-10 or 1d-35 may include a function of delivering all RLC SDUs received until the current time to the upper layer in sequence. The NR RLC entity 1d-10 or 1d-35 may also process the RLC PDUs in sequence according to the order of reception regardless of the order of SNs (out-of-sequence delivery), and deliver the RLC PDUs out-of-sequence to the NR PDCP entity 1d-05 or 1d-40 regardless of the order. When the NR RLC entity 1d-10 or 1d-35 receives a fragment, the fragment can be reassembled with the fragments stored in the buffer or other fragments that are subsequently received into a complete single RLC PDU, and the RLC PDU can be transmitted to the NR PDCP entity 1d-05 or 1d-40.

[0130] The NR RLC layer 1d-10 or 1d-35 may not include the cascading function, and may perform the above-mentioned functions in the NR MAC layer, or replace the cascading function with the multiplexing function of the NR MAC layer.

[0131] In the above description, the out-of-order delivery function of the NR RLC entity may indicate a function of delivering the RLC SDU received from the lower layer directly to the upper layer regardless of the order. When a single RLC SDU is segmented into multiple RLC SDUs and received, the out-of-order delivery function of the NR RLC entity may include a function of reassembling the multiple RLC SDUs and transmitting the reassembled RLC SDUs. The out-of-order delivery function of the NR RLC entity may include a function of storing the RLC SN or PDCP SN of the received RLC PDU and reordering the RLC PDUs, and recording the lost RLC PDUs.

[0132] NR MAC 1d-15 or 1d-30 can be connected to several NR RLC layers configured in one terminal, and the main functions of NR MAC1d-15 or 1d-30 may include some of the following functions.

[0133] - Mapping between logical channels and transport channels

[0134] -Multiplexing / demultiplexing of MAC SDU

[0135] -Dispatch information report

[0136] -HARQ (error correction through HARQ)

[0137] - Priority handling between logical channels of a UE

[0138] - Priority handling between dynamically scheduled UEs

[0139] -MBMS service identification

[0140] -Transmission format selection

[0141] -filling

[0142] The NR PHY layer 1d-20 or 1d-25 can perform channel coding or modulation on the upper layer data and convert it into OFDM symbols, and send the OFDM symbols to the wireless channel; or demodulate the OFDM symbols received via the wireless channel and perform channel decoding on the demodulated OFDM symbols, and transmit the channel-decoded OFDM symbols to the upper layer.

[0143] Figure 1E The present invention is a diagram for describing a process of performing cell reselection by a terminal in an RRC inactive mode RRC_INACTIVE or an RRC idle mode RRC_IDLE in an LTE system according to an embodiment of the present disclosure.

[0144] The cell reselection process may indicate the process by which a terminal in RRC idle mode or RRC inactive mode determines whether to maintain the current serving cell or reselect a neighboring cell as the serving cell when the service quality of the serving cell is lower than that of a neighboring cell due to some reason or due to the mobile terminal.

[0145] Whether to perform a handover is determined by the network, while cell reselection can be determined by the terminal itself based on cell measurement values. As the terminal moves, the cell reselected by the terminal may indicate a neighboring cell that uses the same RAT as the current serving cell or a cell that uses another RAT. Reselecting a neighboring cell that uses a different RAT from the current serving cell may be referred to as inter-RAT cell reselection. When reselecting a cell that uses the same RAT as the current serving cell or a neighboring cell that is located at the same frequency (same frequency) as the current serving cell, it may be referred to as same-frequency cell reselection. In addition, reselecting a cell located at a different frequency (heterogeneous frequency) may be referred to as inter-frequency cell reselection. According to an embodiment of the present disclosure, when the current serving cell is an evolved universal mobile telecommunications system (UMTS) terrestrial radio access (E-UTRA) cell, it may be referred to as evolved UMTS terrestrial radio access network (E-UTRAN) same-frequency cell reselection or E-UTRAN inter-frequency cell reselection.

[0146] refer to Figure 1E , terminal 1e-01 can establish an RRC connection with base station 1e-02 and is in RRC connection mode RRC_CONNECTED (1e-05).

[0147] In operation 1e-10, when there is no data transmission or reception due to a certain reason or a certain period of time, the base station 1e-02 may send an RRC connection release message (RRCConnectionRelease) to the terminal 1e-01. The RRC connection release message may include RRC inactive configuration information (rrc-InactiveConfig).

[0148] In operation 1e-15, when the RRC connection release message includes RRC inactive configuration information, the terminal 1e-01 may switch to the RRC inactive mode; and when the RRC connection release message does not include the RRC inactive configuration information, the terminal 1e-01 may switch to the RRC idle mode. The RRC inactive configuration information may be included in idleModeMobilityControlInfo.

[0149] The frequency priority configuration information for each RAT may include at least one of the following parameters.

[0150] - One or more CarrierFreq or one or more bandClasse: indicates the value of each frequency or frequency band. For example, it may include an absolute radio frequency channel number (ARFNN).

[0151] -Frequency priority value for each CarrierFreq or each bandClasse: For example, the frequency priority value for each CarrierFreq or each bandClasse may represent cellReselectionPriority and / or cellReselectionSubPriority, and cellReselectionPriority may have an integer value, and cellReselectionSubPriority may have a prime value. When both cellReselectionPriority and cellReselectionSubPriority are signaled, the terminal may derive the frequency priority value by adding the two values.

[0152] -T320 timer value In the RRC connection release message sent in operation 1e-10, for each RAT (e.g., EUTRA, Global System for Mobile Communications (GSM) Enhanced Data for GSM Evolution (EDGE) Radio Access Network (GERAN), UMTS Terrestrial Radio Access-Frequency Division Duplex (UTRA-FDD), UTRA-Time Division Duplex (UTRA-TDD), High Rate Packet Data (HRPD), Single Carrier Radio Transmission Technology (1×RTT) and NR), one or more frequency priority configuration information and a time value (e.g., idleModeMobilityControlInfo) applicable regardless of the RAT may be included. In this case, the terminal 1e-01 may store one or more frequency priority configuration information for each RAT. When the T320 timer value is included in the RRC connection release message, the T320 timer value is configured as the value of the T320 timer to run the T320 timer.

[0153] Meanwhile, when the RRC connection release message sent in operation 1e-10 does not include one or more frequency priority configuration information for each RAT and a timer value applicable regardless of the RAT or when the T320 timer expires, the cell reselection priority information broadcast in the system information may be applied.

[0154] In operation 1e-20, the terminal 1e-01 in the RRC idle mode or the RRC inactive mode may perform a cell selection process. Depending on whether the RRC connection release message received in operation 1e-10 includes redirectedCarrierInfo (which may include an information element indicating a value of one or more frequencies or frequency bands used for a specific RAT), the terminal 1e-01 may perform the following cell selection process.

[0155] - Case 1: When the RRC Connection Release message includes redirectedCarrierInfo, the terminal 1e-01 can camp on a suitable cell according to redirectedCarrierInfo. When no suitable cell according to redirectedCarrierInfo is found, the terminal 1e-01 can camp on any suitable cell in the indicated RAT.

[0156] -Case 2: When the RRC connection release message does not include redirectedCarrierInfo, the terminal 1e-01 can select a suitable cell in the EUTRA carrier.

[0157] - Case 3: When no suitable cell is found in Case 1 or Case 2, the terminal 1e-01 may perform a cell selection process based on the stored information to camp on a suitable cell.

[0158] In operation 1e-20, the cell selection criterion may indicate a situation where the following [Equation 1] is satisfied.

[0159] [Equation 1]

[0160] Srxlev>0AND Squal>0 where:

[0161] Srxlev=Qrxlevmeas-(Qrxlevmin+Qrxlevminoffset)-Pcompensation-Qoffsettemp

[0162] Squal=Qqualmeas-(Qqualmin+Qqualminoffset)-Qoffsettemp For the definition of the parameters used in [Equation 1], reference may be made to the 3GPP standard document "36.304: User Equipment (UE) Procedures In Idle Mode", and the parameters may be included in the system information (e.g., SIB1, SIB2) broadcast by the cell. The same applies to the embodiments of the present disclosure.

[0163] In operation 1e-25, the terminal 1e-01 may obtain or receive system information (SIB3, SIB4, ..., SIB8, SIB24). Each system information may include one or more frequency priority configuration information for each RAT (i.e., cell reselection priority information for each RAT). For example, when the terminal 1e-01 has camped on an E-UTRA cell through a cell selection process in operation 1e-20, the frequency priority configuration information for each RAT may be included in the system information in the following form.

[0164] -SIB3: Priority configuration information of the service frequency (the frequency to which the current cell resides)

[0165] -SIB5: Frequency priority configuration information for each EUTRA frequency

[0166] -SIB6: Frequency priority configuration information for each UTRA frequency (UTRA-FDD, UTRA-TDD)

[0167] -SIB7: Frequency priority configuration information for each GERAN frequency

[0168] -SIB8: Frequency priority configuration information for each CDMA2000

[0169] -SIB24: Frequency priority configuration information for each NR frequency

[0170] In addition, parameters for cell reselection may also be included in SIB3, SIB4, SIB5, SIB6, SIB7, SIB8 and SIB24.

[0171] In operation 1e-30, the terminal 1e-01 may perform a cell reselection evaluation procedure. The terminal 1e-01 may perform a cell reselection evaluation procedure on the E-UTRAN frequency and RAT inter-frequency broadcasted in the provided frequency priority configuration information and the provided system information (the UE should only perform cell reselection evaluation on the E-UTRAN frequency and RAT inter-frequency given in the system information and for which the UE has a priority provided). The cell reselection evaluation procedure may indicate the following series of processes.

[0172] - Reselect priority processing

[0173] -Measurement rules for cell reselection

[0174] -Cell reselection criteria

[0175] The method of reselecting a cell may be determined based on whether the RRC connection release message received in operation 1e-10 includes one or more frequency priority configuration information for each RAT and a timer value applicable regardless of the RAT. For example, the following cell reselection method may be used.

[0176] When one or more frequency priority configuration information for each RAT and a time value applicable regardless of the RAT are included in the RRC connection release message, the frequency priority configuration information in the system information obtained in operation 1e-25 may be ignored when the T320 timer is started, and the cell may be reselected by applying the frequency priority configuration information included in the RRC connection release message. When the T320 timer expires, in operation 1e-25, the terminal 1e-01 may reselect the cell by applying the frequency priority configuration information in the obtained system information.

[0177] -When the RRC connection release message does not include one or more frequency priority configuration information for each RAT and a time value applicable regardless of the RAT, the terminal 1e-01 can reselect a cell by applying the frequency priority configuration information in the system information obtained in operation 1e-25.

[0178] For some reasons or to minimize battery consumption, the terminal 1e-01 may perform neighbor cell measurement by applying frequency priority based on the following measurement rules.

[0179] When the reception level and reception quality of the serving cell are higher than the threshold (Srxlev>SIntraSearchP and SIntraSearchQ), the terminal 1e-01 may not perform EUTRA intra-frequency measurement. Otherwise, the terminal 1e-01 may perform EUTRA intra-frequency measurement.

[0180] - The terminal 1e-01 may perform neighbor cell measurement on an EUTRA inter-frequency or a RAT inter-frequency having a higher reselection priority than the frequency of the current serving cell.

[0181] -When the reception level and reception quality of the serving cell are higher than the thresholds (Srxlev>SIntraSearchP and SIntraSearchQ), the terminal 1e-01 may not perform measurements on the EUTRA inter-frequency whose reselection priority is equal to or lower than the frequency of the current serving cell or the RAT inter-frequency whose reselection priority is lower than the frequency of the current serving cell. Otherwise, the terminal 1e-01 may perform measurements on the EUTRA inter-frequency or RAT inter-frequency whose reselection priority is lower than or equal to the frequency of the current serving cell.

[0182] For reference, the thresholds (SIntraSearchP, SIntraSearchQ, SnonIntraSearchP, SnonIntraSearchQ) and the reception level and reception quality of the serving cell can be obtained or derived based on the system information received in operation 1e-25. In addition, for a frequency having a priority equal to that of the serving frequency or a frequency having a priority lower than that of the serving frequency, when the mobility state of the terminal 1e-01 is not low mobility, the terminal 1e-01 can measure a neighboring cell relative to the frequency.

[0183] The terminal 1e-01 may apply different cell reselection evaluation criteria according to the frequency priority. In detail, the terminal 1e-01 may apply different cell reselection criteria to the following four situations.

[0184] - First case: when there is at least one E-UTRAN frequency or RAT inter-frequency with a higher priority than the current serving frequency.

[0185] - Second case: when there is at least one E-UTRAN frequency or RAT inter-frequency with a lower priority than the current serving frequency.

[0186] - The third case: when there is at least one current serving frequency or at least one E-UTRAN inter-frequency having the same priority as the current serving frequency.

[0187] When the cell reselection criteria are applied to the first case,

[0188] -When the terminal 1e-01 determines that the system information (e.g., SIB3) broadcast by the serving cell includes ThreshServingLowQ and a certain period of time (e.g., 1 second) has passed since the terminal 1e-01 camped on the current serving cell,

[0189] -The cell that meets condition A can be reselected.

[0190] Condition A: A cell in an EUTRAN, NR or UTRAN FDDR AT / frequency with high priority satisfies Squal>ThreshX,HighQ in the time period TreselectionRAT, or a cell in an UTRAN TDD, GERAN or CDMA2000 RAT / frequency with high priority satisfies Squal>ThreshX,HighP in the time period TreselectionRAT.

[0191] Otherwise, when a certain time period (e.g., 1 second) has elapsed after the terminal 1e-01 has camped on the current serving cell, and a cell in a RAT / frequency with a high priority satisfies Srxlev > ThreshX,HighP within the time period TreselectionRAT, the terminal 1e-01 can reselect to this cell.

[0192] When applying the cell reselection criterion to the second case,

[0193] - When the terminal 1e-01 determines that ThreshServingLowQ is included in the system information (e.g., SIB3) broadcast by the serving cell and a certain time period (e.g., 1 second) has elapsed after the terminal 1e-01 has camped on the current serving cell,

[0194] - It can reselect to a cell that satisfies condition B.

[0195] - Condition B: The serving cell satisfies Squal < ThreshServing,LowQ within the time period TreselectionRAT and a cell in a EUTRAN, NR or UTRAN FDD RAT / frequency with a low priority satisfies Squal > ThreshX,LowQ, or the serving cell satisfies Squal < ThreshServing,LowQ within the time period TreselectionRAT and a cell in a UTRAN TDD, GERAN or CDMA2000 RAT / frequency with a low priority satisfies Squal > ThreshX,LowP.

[0196] Otherwise, when a certain time period has elapsed after the terminal 1e-01 has camped on the current serving cell (e.g., 1 second) and a cell in a RAT / frequency with a low priority satisfies Srxlev > ThreshX,LowP within the time period TreselectionRAT, the terminal 1e-01 can reselect to this cell.

[0197] When applying the cell reselection criterion to the third case, the terminal 1e-01 can determine the ranking of all cells that satisfy the cell selection criterion. That is, for all cells that satisfy the cell selection criterion, the terminal 1e-01 can obtain the ranking of each cell based on the reference signal received power (RSRP) measurement value. The ranking of the serving cell and neighboring cells can be calculated respectively based on the following [Equation 2].

[0198] [Equation 2]

[0199] Rs = Qmeas,s + Qhyst - Qoffsettemp + QoffsetSCPTM

[0200] Rn=Qmeas,n-Qoffset-Qoffsettemp+QoffsetSCPTM

[0201] For the definition of the parameters used in [Equation 2], reference may be made to the 3GPP standard document "36.304: User Equipment (UE) Procedure in Idle Mode", and the parameters may be included in the system information broadcast by the cell. The same applies to Embodiment 2 of the present disclosure to which [Equation 2] is applied. The terminal 1e-01 may reselect the highest ranked cell (if the cell is ranked as the best cell, the UE will perform cell reselection on the cell). In any case, when the following conditions are met, the terminal 1e-01 may reselect a new cell.

[0202] - When the new cell is ranked higher than the serving cell in the time period TreselectionRAT.

[0203] - When a certain period of time (eg, 1 second) has passed after camping on the current serving cell.

[0204] -When multiple cells that meet the cell reselection criteria in the first case, the second case, or the third case have different priorities, the terminal 1e-10 can perform cell reselection so that the RAT / frequency with a higher priority takes precedence over the RAT / frequency with a lower priority (if multiple cells of different priorities meet the cell reselection criteria, the cell reselection should prioritize the RAT / frequency with a higher priority over the RAT / frequency with a lower priority). When reselecting cells in the first case or the second case and multiple cells meet the cell reselection criteria, the terminal 1e-01 can reselect the cell with the highest ranking among the cells with the highest priority frequency. For reference, the parameters applied to the cell reselection criteria may be included in the system information received in operation 1e-25. In addition, the parameter TreselectionRAT may be adjusted based on the mobility state of the terminal 1e-01. For example, for an E-UTRA cell and in a high mobility state, TreselectionEUTRA may be multiplied by sf-High (a speed-related adjustment factor for TreselectionEUTRA) to obtain TreselectionEUTRA. The QHyst parameter may be adjusted based on the mobility state of the terminal 1e-01. For example, for an E-UTRA cell and in case of a high mobility state, sf-High (speed-dependent adjustment factor for TreselectionEUTRA) may be added to Qhyst to derive Qhyst.

[0205] In operation 1e-35, terminal 1e-01 in RRC idle mode or RRC inactive mode may reselect a new cell through operation 1e-30.

[0206] Figure 1F The present invention is a diagram for describing a process of performing cell reselection by a terminal in an RRC inactive mode RRC_INACTIVE or an RRC idle mode RRC_IDLE in a next generation mobile communication system according to an embodiment of the present disclosure.

[0207] refer to Figure 1F In operation 1f-05, the terminal 1f-01 can be converted to the RRC connection mode RRC_CONNECTED through the RRC establishment process or the RRC recovery process with the base station 1f-02.

[0208] In operation 1f-10, the terminal 1f-01 in the RRC connection mode may send UECapabilityInformation including the IRAT-ParametersNR information element to the base station 1f-02. The IRAT-ParametersNR information element may include at least one of the following.

[0209] - Indicator indicating whether en-DC is supported

[0210] - Indicator indicating whether ng-en-dc is supported

[0211] - Indicator indicating whether eventB2 is supported

[0212] -NR frequency band information supported by the terminal in (NG)en-dc

[0213] - An indicator indicating that the frequency priority configured as a dedicated frequency priority can be switched to the frequency priority included in the broadcast signaling

[0214] In operation 1f-15, the base station 1f-02 may send an RRC connection release message to the terminal 1f-01 so that the terminal 1f-01 in the RRC connection mode is switched to the RRC idle mode or the RRC inactive mode. In the RRC connection release message, the cell reselection priority (CRP) regarding the first RAT, the CRP regarding the second RAT, and the T320 timer value may be included. For example, the above information may be included in the idleModeMobilityControlInfo information element, and the idleModeMobilityControlInfo information element may be included in the RRC connection release message. The CRP may indicate the frequency priority value used for each frequency. According to an embodiment of the present disclosure, the first RAT may indicate EUTRA, and according to an embodiment of the present disclosure, the second RAT may indicate other RATs other than EUTRA (e.g., NR, UTRA-FDD, UTRA-TDD, CDMA2000). When the RRC connection release message includes a CRP regarding the first RAT and / or a CRP regarding the second RAT, the terminal 1f-01 may store the CRP. In the above-mentioned embodiment of the present disclosure, CRP may indicate one or more frequency priority configuration information for each RAT. When the T320 timer value is included in the RRC connection release message, the T320 timer value may be configured as the value of the T320 timer to run the T320 timer. When the T320 timer expires, the terminal 1f-01 may discard the frequency priority configuration information received and configured via the RRC connection release message.

[0215] In operation 1f-20, the terminal 1f-01 that has been converted to the RRC idle mode or the RRC inactive mode may perform a cell selection process. Figure 1F For ease of description, the cell with which the terminal 1f-01 performs RRC connection is shown as the same as the cell in which the terminal 1f-01 has camped. However, the cell in which the terminal 1f-01 has camped may obviously be different from the cell in which the terminal 1f-01 has performed RRC connection. That is, the terminal 1f-01 may choose to camp in a suitable cell, and the selected cell may be a cell for RRC connection or may not be a cell for RRC connection. The above description may also be applied to the following reference Figures 1G to 1L Describe the cell selection process.

[0216] In operation 1f-25, the terminal 1f-01 may receive system information from the cell in which it has camped through cell selection. The system information may include parameters for cell reselection. For example, the following parameters may be included:

[0217] - CRP information about the first RAT: SIB3 and SIB5

[0218] - A first CRP (legacy CRP) and a second CRP (CRP for EN-DC) of the serving frequency are included in SIB3.

[0219] - Include the first CRP and the second CRP for each first RAT inter-frequency in SIB5.

[0220] -CRP information about the second RAT: SIB6, SIB7, SIB8, SIB24

[0221] - A first CRP for each frequency in the second RAT. For example, a CRP for each UTRA frequency may be included in SIB6, and a CRP for each NR frequency may be included in SIB24.

[0222] For ease of description, it will be described as follows: for the first RAT, each E-UTRAN frequency may include two CRPs in the system information; and for the second RAT, each frequency may include one CRP in the system information. That is, for the first RAT, each E-UTRAN frequency may include two or more CRPs in the system information; or for the second RAT, each frequency may include multiple CRPs in the system information. The above description can obviously be applied to the following.

[0223] In operation 1f-30, the terminal 1f-01 may perform a cell reselection evaluation process. The terminal 1f-01 may perform a cell reselection evaluation process on the EUTRA frequency and RAT inter-frequency broadcast in the provided frequency priority configuration information and the provided system information (the UE should only perform cell reselection evaluation on the E-UTRAN frequency and RAT inter-frequency given in the system information and the UE has a priority provided for it). The cell reselection evaluation process may indicate the following series of processes.

[0224] - Reselect priority processing

[0225] -Measurement rules for cell reselection

[0226] -Cell reselection criteria

[0227] Based on the capabilities of the terminal 1f-01 in the RRC idle mode or the RRC inactive mode, the reselection priority processing may be applied differently in the first RAT and the second RAT.

[0228] -When terminal 1f-01 is a terminal with (NG) EN-DC capability and NR is enabled, or terminal 1f-01 is a terminal with (NG) EN-DC capability and NR is enabled and configured as a dedicated frequency priority that can be switched to the frequency priority included in the broadcast signaling, the frequency priority can be determined by applying the second CRP included in SIB3 to the current service frequency. That is, even when the CRP for the first RAT is included in the RRC connection release message received in operation 1f-15, the terminal 1f-01 can also apply the second CRP included in the received SIB3. This is applicable regardless of the activation of the T320 timer.

[0229] -When terminal 1f-01 is a terminal with (NG) EN-DC capability and NR is enabled, or terminal 1f-01 is a terminal with (NG) EN-DC capability and NR is enabled and configured as a dedicated frequency priority that can be switched to the frequency priority included in the broadcast signaling, terminal 1f-01 can determine the frequency priority by applying the second CRP included in SIB5 to the E-UTRAN inter-frequency. That is, even when the CRP about the first RAT is included in the RRC connection release message received in operation 1f-15, terminal 1f-01 can also apply the second CRP included in the received SIB5. This is applicable regardless of the activation of the T320 timer.

[0230] -When the terminal 1f-01 is a terminal with (NG) EN-DC capability but NR is disabled, or the terminal 1f-01 is a terminal with (NG) EN-DC capability but is configured as a dedicated frequency priority that is not switchable to the frequency priority included in the broadcast signaling, the terminal 1f-01 may determine the priority regarding the current service frequency and the E-UTRAN inter-frequency by applying the CRP regarding the first RAT included in the RRC connection release message received in operation 1f-15. That is, even when the first CRP and / or the second CRP regarding the first RAT are included in the system information received in operation 1f-25, the terminal 1f-01 may ignore them and apply the CRP regarding the first RAT included in the RRC connection release message when the T320 timer is started. When the T320 timer expires or the T320 timer is not running, the terminal 1f-01 may apply the first CRP regarding the first RAT in the system information received in operation 1f-25 to the current service frequency and the E-UTRAN inter-frequency.

[0231] -Terminal 1f-01 may determine the frequency priority regarding the second RAT by applying the CRP regarding the second RAT included in the RRC connection release message received in operation 1f-15. That is, even when the first CRP regarding the second RAT is included in the system information received in operation 1f-25, the terminal 1f-01 may ignore it and apply the CRP regarding the second RAT included in the RRC connection release message when the T320 timer is started. When the T320 timer expires or the T320 timer is not running, the terminal 1f-01 may determine the frequency priority by applying the first CRP regarding the second RAT in the system information received in operation 1f-25 to the second RAT.

[0232] Regarding the measurement rule, for some reasons or to minimize battery consumption, the terminal 1f-01 may perform neighbor cell measurement by applying frequency priority based on the measurement rule. This may be the same as the above-mentioned embodiment of the present disclosure.

[0233] For the cell reselection evaluation criteria, the terminal 1f-01 may apply different cell reselection evaluation criteria according to the frequency priority. This may be the same as the above-mentioned embodiment of the present disclosure.

[0234] In operation 1f-35, terminal 1f-01 in RRC idle mode or RRC inactive mode can reselect a new cell 1f-03 through operation 1f-30.

[0235] In operation 1f-40, the terminal 1f-01 may obtain system information including cell reselection parameters from the reselected cell 1f-03.

[0236] In operation 1f-45, when the second CRP regarding the first RAT is included in the received system information, the above-mentioned operation 1f-30 may be performed to perform a cell reselection process. When only the first CRP regarding the first RAT is included in the received system information, the terminal 1f-01 may perform a cell reselection process by applying the CRP regarding the first RAT and the CRP regarding the second RAT included in the RRC connection release message received in operation 1f-15 when the T320 timer is started. When only the first CRP is included in the received system information regarding the first RAT and the T320 timer expires or is not running, the terminal 1f-01 may perform a cell reselection process by applying the CRP regarding the first RAT and the CRP regarding the second RAT included in the system information received in operation 1f-40.

[0237] In the embodiments of the present disclosure, for the convenience of description, (NG) EN-DC is described as an example. However, the embodiments of the present disclosure are not limited to being applied to (NG) EN-DC, but can also be applied to NE-DC and NR-DC based on the same principle.

[0238] Figure 1G The present invention is a diagram for describing a process of performing cell reselection by a terminal in an RRC inactive mode RRC_INACTIVE or an RRC idle mode RRC_IDLE in a next generation mobile communication system according to an embodiment of the present disclosure.

[0239] refer to Figure 1G In operation 1g-05, terminal 1g-01 can be converted to RRC connection mode RRC_CONNECTED through an RRC establishment process or an RRC recovery process with base station 1g-02.

[0240] In operation 1g-10, the terminal 1g-01 in the RRC connected mode may send UECapabilityInformation including the IRAT-ParametersNR information element to the base station 1g-02. The IRAT-ParametersNR information element may include at least one of the following.

[0241] - Indicator indicating whether en-DC is supported

[0242] - Indicator indicating whether ng-en-dc is supported

[0243] - Indicator indicating whether eventB2 is supported

[0244] -NR frequency band information supported by the terminal in (NG)en-dc

[0245] - An indicator indicating that the frequency priority configured as a dedicated frequency priority can be switched to the frequency priority included in the broadcast signaling

[0246] In operation 1g-15, the base station 1g-02 may send an RRC connection release message to the terminal 1g-01 so that the terminal 1g-01 in the RRC connection mode switches to the RRC idle mode or the RRC inactive mode. The RRC connection release message may include a CRP about the first RAT, a CRP about the second RAT, a T320 timer value, and a notOverRideIndication (an indicator indicating that the frequency priority included in, for example, broadcast signaling (e.g., system information) is ignored but the frequency priority configured by dedicated signaling (e.g., RRC connection release message) is applied). For example, the above information may be included in the idleModeMobilityControlInfo information element, and the idleModeMobilityControlInfo information element may be included in the RRC connection release message. According to an embodiment of the present disclosure, the first RAT may indicate EUTRA, and according to an embodiment of the present disclosure, the second RAT may indicate other RATs other than EUTRA (e.g., NR, UTRA-FDD, UTRA-TDD, CDMA2000). When the RRC connection release message includes a CRP about the first RAT and / or a CRP about the second RAT, the terminal 1g-01 may store the CRP. In the above-mentioned embodiment of the present disclosure, the CRP may indicate one or more frequency priority configuration information for each RAT. When the RRC connection release message includes a T320 timer value, the T320 timer value may be configured as the value of the T320 timer to run the T320 timer. When the T320 timer expires, the terminal 1g-01 may discard the frequency priority configuration information received and configured via the RRC connection release message.

[0247] In operation 1g-20, terminal 1g-01 that has switched to RRC idle mode or RRC inactive mode may perform a cell selection process.

[0248] In operation 1g-25, terminal 1g-01 may receive system information from the cell in which it has camped through cell selection. The system information may include parameters for cell reselection. For example, the following parameters may be included:

[0249] - CRP information about the first RAT: SIB3 and SIB5

[0250] - A first CRP (legacy CRP) and a second CRP (CRP for EN-DC) of a serving frequency may be included in SIB3.

[0251] - A first CRP and a second CRP for each first RAT inter-frequency may be included in SIB5.

[0252] -CRP information about the second RAT: SIB6, SIB7, SIB8, SIB24

[0253] - A first CRP for each frequency in the second RAT. For example, a CRP for each UTRA frequency may be included in SIB6, and a CRP for each NR frequency may be included in SIB24.

[0254] For ease of description, it will be described as follows: for the first RAT, each E-UTRAN frequency may include two CRPs in the system information; and for the second RAT, each frequency may include one CRP in the system information. That is, for the first RAT, each E-UTRAN frequency may include two or more CRPs in the system information; or for the second RAT, each frequency may include multiple CRPs in the system information. The above description can obviously be applied to the following.

[0255] In operation 1g-30, terminal 1g-01 may perform a cell reselection evaluation process. Terminal 1g-01 may perform a cell reselection evaluation process on the EUTRA frequency and RAT inter-frequency provided in the provided frequency priority configuration information and the provided system information (the UE should only perform cell reselection evaluation on the E-UTRAN frequency and RAT inter-frequency given in the system information and the UE has a priority provided for it). The cell reselection evaluation process may indicate the following series of processes.

[0256] - Reselect priority processing

[0257] -Measurement rules for cell reselection

[0258] -Cell reselection criteria

[0259] Based on the capabilities of the terminal 1g-01 in the RRC idle mode or the RRC inactive mode and whether the RRC connection release message received in operation 1g-15 includes notOverRideIndication, the reselection priority processing may be applied differently in the first RAT and the second RAT.

[0260] When notOverRideIndication is included in the received RRC connection release message and the terminal 1g-01 supports notOverRideIndication, the terminal 1g-01 can apply the frequency priority configuration information by applying the CRP included in the RRC connection release message when the T320 timer is started. That is, the terminal 1g-01 can ignore the CRP in the system information received in operation 1g-25. The reason for including NotOverRideIndication in the RRC connection release message is that the base station 1g-02 has included the frequency priority configuration information in consideration of the capability of the terminal 1g-01.

[0261] -When the T320 timer expires or is not running, the terminal 1g-01 may apply the frequency priority configuration information based on the CRP included in the system information received in operation 1g-25. For example, when the terminal 1g-01 is a terminal with (NG) EN-DC capability and NR is enabled, or the terminal 1g-01 is a terminal with (NG) EN-DC capability and NR is enabled and the frequency priority configured as dedicated is switchable to the frequency priority included in the broadcast signaling, the second CRP in SIB3 and SIB5 may be applied to the first RAT, and the first CRP may be applied to the second RAT. Otherwise, the first CRP in SIB3 and SIB5 may be applied to the first RAT, and the first CRP may be applied to the second RAT.

[0262] -When notOverRideIndication is not included in the received RRC connection release message and terminal 1g-01 is a terminal with (NG) EN-DC capability and NR is enabled, or terminal 1g-01 is a terminal with (NG) EN-DC capability and NR is enabled and configured as a dedicated frequency priority that can be switched to the frequency priority included in the broadcast signaling, terminal 1g-01 can determine the frequency priority by applying the second CRP included in SIB3 to the current service frequency, or determine the frequency priority by applying the second CRP included in SIB5 to the E-UTRAN inter-frequency. That is, even when the CRP for the first RAT is included in the RRC connection release message received in operation 1g-15, terminal 1g-01 can also apply the second CRP included in the received SIB3 / SIB5. This is applicable regardless of the activation of the T320 timer. When terminal 1g-01 is a terminal with (NG) EN-DC capability and NR is disabled, or the frequency priority configured as dedicated is not switchable to the frequency priority included in the broadcast signaling, terminal 1g-01 can determine the frequency priority by applying the CRP regarding the first RAT to the E-UTRAN frequency in the RRC connection release message when the T320 timer is started.

[0263] - The terminal 1g-01 may apply the CRP about the second RAT included in the RRC connection release message received in operation 1g-15 to the second RAT. That is, even when the first CRP about the second RAT is included in the system information received in operation 1g-25, the terminal 1g-01 may ignore it and apply the CRP about the second RAT when the T320 timer is started. When the T320 timer expires or the T320 timer is not running, the terminal 1g-01 may apply the first CRP about the second RAT included in the system information received in operation 1g-25 to the second RAT.

[0264] For some reasons or to minimize battery consumption, the terminal 1g-01 may perform neighbor cell measurement by applying frequency priority based on the following measurement rules. This may be the same as the above-mentioned embodiment of the present disclosure.

[0265] Terminal 1g-01 may apply different cell reselection evaluation criteria according to frequency priority. This may be the same as the above-mentioned embodiment of the present disclosure.

[0266] In operation 1g-35, terminal 1g-01 in RRC idle mode or RRC inactive mode can reselect a new cell 1g-03 through operation 1g-30.

[0267] In operation 1g-40, the terminal 1g-01 may obtain system information including cell reselection parameters from the reselected cell 1g-03.

[0268] In operation 1g-45, when the second CRP regarding the first RAT is included in the received system information, the terminal 1g-01 may perform the above-mentioned operation 1g-30 to perform the cell reselection process. When the second CRP regarding the first RAT is not included in the system information received in operation 1g-40, the terminal 1g-01 may perform the cell reselection process by determining the frequency priority based on the received system information, or may perform the cell reselection process by determining the frequency priority based on the RRC connection release message received in operation 1g-15 when the T320 timer is started.

[0269] In the embodiments of the present disclosure, for the convenience of description, (NG) EN-DC is described as an example. However, the embodiments of the present disclosure are not limited to being applied to (NG) EN-DC, but can also be applied to NE-DC and NR-DC based on the same principle.

[0270] Figure 1HThe present invention is a diagram for describing a process of performing cell reselection by a terminal in an RRC inactive mode RRC_INACTIVE or an RRC idle mode RRC_IDLE in a next generation mobile communication system according to an embodiment of the present disclosure.

[0271] refer to Figure 1H In operation 1h-05, the terminal 1h-01 can be converted to RRC connection mode RRC_CONNECTED through the RRC establishment process or RRC recovery process 1h-05 with the base station 1h-02.

[0272] In operation 1h-10, the terminal 1h-01 in the RRC connected mode may send UECapabilityInformation including the IRAT-ParametersNR information element to the base station 1h-02. The IRAT-ParametersNR information element may include at least one of the following.

[0273] - Indicator indicating whether en-DC is supported

[0274] - Indicator indicating whether ng-en-dc is supported

[0275] - Indicator indicating whether eventB2 is supported

[0276] -NR frequency band information supported by the terminal in (NG)en-dc

[0277] - An indicator indicating that the frequency priority configured as a dedicated frequency priority can be switched to the frequency priority included in the broadcast signaling

[0278] In operation 1h-15, the base station 1h-02 may send an RRC connection release message to the terminal 1h-01 so that the terminal 1h-01 in the RRC connection mode switches to the RRC idle mode or the RRC inactive mode. The RRC connection release message may include a CRP about the first RAT, a CRP about the second RAT, a T320 timer value, and an alternativeCRPIndication (an indicator indicating that the frequency priority configured by the dedicated signaling (e.g., RRC connection release message) according to the terminal's capabilities and the system information of the base station is ignored, and the frequency priority broadcast by the broadcast signaling (e.g., system information) is applied). For example, the above information may be included in the idleModeMobilityControlInfo information element, and the idleModeMobilityControlInfo information element may be included in the RRC connection release message. According to an embodiment of the present disclosure, the first RAT may indicate EUTRA, and according to an embodiment of the present disclosure, the second RAT may indicate other RATs other than EUTRA (e.g., NR, UTRA-FDD, UTRA-TDD, CDMA2000). When the RRC connection release message includes a CRP about the first RAT and / or a CRP about the second RAT, the terminal 1h-01 may store the CRP. In the above-mentioned embodiment of the present disclosure, the CRP may indicate a priority value for each frequency in each RAT. When the RRC connection release message includes a T320 timer value, the T320 timer value may be configured as the value of the T320 timer to start the T320 timer. When the T320 timer expires, the terminal 1h-01 may discard the frequency priority configuration information received and configured via the RRC connection release message.

[0279] In operation 1h-20, the terminal 1h-01 that has switched to the RRC idle mode or the RRC inactive mode may perform a cell selection process.

[0280] In operation 1h-25, the terminal 1h-01 may receive system information from the cell in which it has camped through cell selection. The system information may include parameters for cell reselection. For example, the following parameters may be included:

[0281] - CRP information about the first RAT: SIB3 and SIB5

[0282] - The first CRP (legacy CRP) and the second CRP (CRP for EN-DC) of the serving frequency may be included in SIB3.

[0283] - The first CRP and the second CRP for each first RAT inter-frequency may be included in SIB5.

[0284] -CRP information about the second RAT: SIB6, SIB7, SIB8, SIB24

[0285] - A first CRP for each frequency in the second RAT. For example, a CRP for each UTRA frequency may be included in SIB6, and a CRP for each NR frequency may be included in SIB24.

[0286] For ease of description, it will be described as follows: for the first RAT, each E-UTRAN frequency may include two CRPs in the system information; and for the second RAT, each frequency may include one CRP in the system information. That is, for the first RAT, each E-UTRAN frequency may include two or more CRPs in the system information; or for the second RAT, each frequency may include multiple CRPs in the system information. The above description can obviously be applied to the following.

[0287] The alternativeCRPIndication included in the RRC Connection Release message may also be used as an indicator indicating which CRP is to be used for each frequency in each RAT.

[0288] In operation 1h-30, terminal 1h-01 may perform a cell reselection evaluation process. Terminal 1h-01 may perform a cell reselection evaluation process on EUTRA frequencies and RAT inter-frequency broadcast in the provided frequency priority configuration information and the provided system information (UE should only perform cell reselection evaluation on E-UTRAN frequencies and RAT inter-frequency given in the system information and for which the UE has a priority provided). The cell reselection evaluation process may indicate the following series of processes.

[0289] - Reselect priority processing

[0290] -Measurement rules for cell reselection

[0291] -Cell reselection criteria

[0292] Based on the capabilities of the terminal 1h-01 in the RRC idle mode or the RRC inactive mode and whether the RRC connection release message received in operation 1h-15 includes an alternativeCRPIndication, the reselection priority processing may be applied differently in the first RAT and the second RAT.

[0293] When the received RRC connection release message includes alternativeCRPIndication and terminal 1h-01 supports alternativeCRPIndication, terminal 1h-01 is a terminal with (NG)EN-DC capability and NR is enabled, or terminal 1h-01 is a terminal with (NG)EN-DC capability and NR is enabled and configured as a dedicated frequency priority that can be switched to the frequency priority included in the broadcast signaling, terminal 1h-01 can determine the frequency priority by applying the second CRP included in SIB3 to the current service frequency or applying the second CRP included in SIB5 to the E-UTRAN heterofrequency. That is, even when the CRP regarding the first RAT is included in the RRC connection release message received in operation 1h-15, terminal 1h-01 may apply the second CRP included in SIB3 or SIB5. This applies regardless of the startup of the T320 timer. The reason why alternativeCRPIndication is included in the RRC connection release message is that even when the base station 1h-02 includes frequency priority configuration information in the RRC connection release message in consideration of the capability of the terminal 1h-01, it is difficult to determine the mobility of the terminal 1h-01 in the RRC idle mode or the RRC inactive mode. When the second CRP is not broadcast in SIB3 or SIB5, or when NR is disabled, or the frequency priority configured as a dedicated one cannot be switched to the frequency priority included in the broadcast signaling, the terminal 1h-01 can determine the frequency priority by applying the CRP included in the RRC connection release message when the T320 timer is started. That is, the terminal 1h-01 can ignore the CRP regarding the first RAT included in the system information received in operation 1h-25.

[0294] -When the T320 timer is started, the terminal 1h-01 may determine the frequency priority by applying the CRP about the second RAT included in the RRC connection release message to the second RAT. When the T320 timer is not started or expires, the terminal 1h-01 may determine the frequency priority by applying the first CRP about the second RAT included in the system information to the second RAT.

[0295] For some reasons or to minimize battery consumption, the terminal 1h-01 may perform neighbor cell measurement by applying frequency priority based on the following measurement rules. This may be the same as the above-mentioned embodiment of the present disclosure.

[0296] The terminal 1h-01 may apply different cell reselection evaluation criteria according to the frequency priority. This may be the same as the above-mentioned embodiment of the present disclosure.

[0297] In operation 1h-35, the terminal 1h-01 in RRC idle mode or RRC inactive mode can reselect a new cell 1h-03 through operation 1h-30.

[0298] In operation 1h-40, the terminal 1h-01 may obtain system information including cell reselection parameters from the reselected cell 1h-03.

[0299] In operation 1h-45, when the second CRP about the first RAT is included in the received system information, the terminal 1h-01 may perform the above-mentioned operation 1h-30 to perform the cell reselection process. When the second CRP about the first RAT is not included in the system information received in operation 1h-40, when the T320 timer is started, the terminal 1h-01 may determine the frequency priority based on the RRC connection release message received in operation 1h-15 and perform the cell reselection process. When the T320 timer expires or is not running, the terminal 1h-01 may perform the cell reselection process by determining the frequency priority based on the system information received in operation 1h-40.

[0300] In the embodiments of the present disclosure, for the convenience of description, (NG) EN-DC is described as an example. However, the embodiments of the present disclosure are not limited to being applied to (NG) EN-DC, but can also be applied to NE-DC and NR-DC based on the same principle.

[0301] Fig. 1I The present invention is a diagram for describing a process of performing cell reselection by a terminal in an RRC inactive mode RRC_INACTIVE or an RRC idle mode RRC_IDLE in a next generation mobile communication system according to an embodiment of the present disclosure.

[0302] refer to Fig. 1I In operation 1i-05, the terminal 1i-01 can be converted to the RRC connection mode RRC_CONNECTED through the RRC establishment process or the RRC recovery process with the base station 1i-02.

[0303] In operation 1i-10, the terminal 1i-01 in the RRC connected mode may send UECapabilityInformation including the IRAT-ParametersNR information element to the base station 1i-02. The IRAT-ParametersNR information element may include at least one of the following.

[0304] - Indicator indicating whether en-DC is supported

[0305] - Indicator indicating whether ng-en-dc is supported

[0306] - Indicator indicating whether eventB2 is supported

[0307] -NR frequency band information supported by the terminal in (NG)en-dc

[0308] -Indicator indicating whether multiple CRPs are available for each E-UTRAN frequency

[0309] - An indicator indicating whether multiple CRPs are available for each RAT frequency

[0310] In operation 1i-15, the base station 1i-02 may send an RRC connection release message to the terminal 1i-01 so that the terminal 1i-01 in the RRC connection mode switches to the RRC idle mode or the RRC inactive mode. The RRC connection release message may include a first CRP about the first RAT, a second CRP about the first RAT (preferentially used for (NG) EN-DC), a CRP about the second RAT, and a T320 timer value. For example, the above information may be included in the idleModeMobilityControlInfo information element, and the idleModeMobilityControlInfo information element may be included in the RRC connection release message. According to an embodiment of the present disclosure, the first RAT may indicate EUTRA, and according to an embodiment of the present disclosure, the second RAT may indicate other RATs other than EUTRA (e.g., NR, UTRA-FDD, UTRA-TDD, CDMA2000).

[0311] For ease of description, it will be described as follows: In the RRC connection release message according to an embodiment of the present disclosure, for the first RAT, each E-UTRAN frequency may include two CRPs; and for the second RAT, each frequency may include one CRP. That is, for the first RAT, multiple CRPs for each E-UTRAN frequency may be included; or for the second RAT, multiple CRPs for each frequency may be included. The above description is obviously applicable to the following. In addition, an indicator indicating which CRP of the multiple CRPs is applied may also be included in the RRC connection release message.

[0312] When the RRC connection release message includes a first CRP about the first RAT and / or a second CRP about the first RAT and / or a CRP about the second RAT, the terminal 1i-01 may store the first CRP and / or the second CRP and / or the CRP. In the above-mentioned embodiment of the present disclosure, the CRP may indicate a priority value for each frequency in each RAT. When the RRC connection release message includes a T320 timer value, the T320 timer value may be configured as the value of the T320 timer to run the T320 timer. When the T320 timer expires, the terminal 1i-01 may discard the frequency priority configuration information received and configured via the RRC connection release message.

[0313] In operation 1i-20, the terminal 1i-01 that has transitioned to the RRC idle mode or the RRC inactive mode may perform a cell selection process.

[0314] In operation 1i-25, the terminal 1i-01 may receive system information from the cell in which it has camped through cell selection. The system information may include parameters for cell reselection. For example, the following parameters may be included:

[0315] - CRP information about the first RAT: SIB3 and SIB5

[0316] - The first CRP (legacy CRP) and the second CRP (CRP for EN-DC) of the serving frequency may be included in SIB3.

[0317] - The first CRP and the second CRP for each first RAT inter-frequency may be included in SIB5.

[0318] -CRP information about the second RAT: SIB6, SIB7, SIB8, SIB24

[0319] - A first CRP for each frequency in the second RAT. For example, a CRP for each UTRA frequency may be included in SIB6, and a CRP for each NR frequency may be included in SIB24.

[0320] For ease of description, it will be described as: for the first RAT, each E-UTRAN frequency may include two CRPs in the system information; and for the second RAT, each frequency may include one CRP in the system information. That is, for the first RAT, each E-UTRAN frequency may include two or more CRPs in the system information; or for the second RAT, each frequency may include multiple CRPs in the system information. The above description can obviously be applied to the following. . The above description can obviously be applied to the following. In addition, when the RRC connection release message includes an indicator indicating which of the multiple CRPs is to be applied, the terminal 1i-01 can apply the indicator to select one of the multiple CRPs in the system information.

[0321] In operation 1i-30, the terminal 1i-01 may perform a cell reselection evaluation process. The terminal 1i-01 may perform a cell reselection evaluation process on the EUTRA frequency and RAT inter-frequency provided in the provided frequency priority configuration information and the provided system information (the UE should only perform cell reselection evaluation on the E-UTRAN frequency and RAT inter-frequency given in the system information and the UE has a priority provided for it). The cell reselection evaluation process may indicate the following series of processes.

[0322] - Reselect priority processing

[0323] -Measurement rules for cell reselection

[0324] -Cell reselection criteria

[0325] The reselection priority processing can be determined based on the capabilities of the terminal 1i-01 in RRC idle mode or RRC inactive mode, the frequency priority configuration information about the first RAT and the frequency priority configuration information about the second RAT included in the RRC connection release message received in operation 1i-15.

[0326] -When the T320 timer is started, and when the terminal 1i-01 is a terminal with (NG)EN_DC capability and NR is enabled, or the terminal 1i-01 is a terminal with (NG)EN-DC capability and NR is enabled and two CRPs are available for each E-UTRAN frequency (that is, when the terminal is able to select and apply one of the two CRPs for each E-UTRAN frequency included in the RRC connection release message), the terminal 1i-01 can determine the frequency priority by applying the second CRP for the first RAT included in the RRC connection release message received in operation 1i-15 to the current serving frequency and the E-UTRAN inter-frequency.

[0327] -When the T320 timer is started, when NR is disabled or it is impossible to select and apply one of the two CRPs for each E-UTRAN frequency included in the RRC connection release message, the terminal 1i-01 can determine the frequency priority by applying the first CRP about the first RAT included in the RRC connection release message received in operation 1i-15 to the current serving frequency and the E-UTRAN inter-frequency.

[0328] - When the T320 timer is started, the terminal 1i-01 may determine the frequency priority by applying the CRP about the second RAT included in the RRC Connection Release message received in operation 1i-15 to the second RAT.

[0329] -When the T320 timer is not running or expires, the terminal 1i-01 may apply the frequency priority configuration information included in the system information. Here, when the terminal 1i-01 is a terminal with (NG) EN_DC capability and NR is enabled, or the terminal 1i-01 is a terminal with (NG) EN_DC capability and NR is enabled and the second CRP in SIB3 / SIB5 is applicable, the terminal 1i-01 may apply the frequency priority configuration information by applying the second CRP included in SIB3 received in operation 1i-25 to the current serving frequency, and apply the frequency priority configuration information by applying the second CRP included in SIB5 received in 1i-25 to the E-UTRAN inter-frequency. The terminal 1i-01 may apply the frequency priority configuration information by applying the first CRP included in the system information received in operation 1i-25 to the second RAT.

[0330] For some reasons or to minimize battery consumption, the terminal 1i-01 may perform neighbor cell measurement by applying frequency priority based on the following measurement rules. This may be the same as the above-mentioned embodiment of the present disclosure.

[0331] Terminal 1i-01 may apply different cell reselection evaluation criteria according to frequency priority. This may be the same as the above-mentioned embodiment of the present disclosure.

[0332] In operation 1i-35, terminal 1i-01 in RRC idle mode or RRC inactive mode can reselect a new cell 1i-03 through operation 1i-30.

[0333] In operation 1i-40, the terminal 1i-01 may obtain system information including cell reselection parameters from the reselected cell 1i-03.

[0334] In operation 1i-45, when the second CRP about the first RAT is included in the received system information, the terminal 1i01 may perform the above-mentioned operation 1i-30 to perform the cell reselection process. When the second CRP about the first RAT is not included in the system information received in operation 1i-40, when the T320 timer is started, the terminal 1i-01 may determine the frequency priority and perform the cell reselection process by applying the first CRP for each frequency in each RAT included in the RRC connection release message received in operation 1i-15. When the second CRP about the first RAT is not included in the system information received in operation 1i-40 and the T320 timer is not running or expired, the terminal 1i-01 may determine the frequency priority and perform the cell reselection process by applying the first CRP for each frequency in each RAT included in the RRC connection release message received in operation 1i-40.

[0335] In the embodiments of the present disclosure, for the convenience of description, (NG) EN-DC is described as an example. However, the embodiments of the present disclosure are not limited to being applied to (NG) EN-DC, but can also be applied to NE-DC or NR-DC based on the same principle.

[0336] Figure 1J The present invention is a diagram for describing a process of performing cell reselection by a terminal in an RRC inactive mode RRC_INACTIVE or an RRC idle mode RRC_IDLE in a next generation mobile communication system according to an embodiment of the present disclosure.

[0337] refer to Figure 1J In operation 1j-05, the terminal 1j-01 can be converted to the RRC connection mode RRC_CONNECTED through the RRC establishment process or the RRC recovery process with the base station 1j-02.

[0338] In operation 1j-10, the terminal 1j-01 in RRC connection mode may send UECapabilityInformation including an IRAT-ParametersNR information element to the base station 1j-02. The IRAT-ParametersNR information element may include at least one of the following.

[0339] - Indicator indicating whether en-DC is supported

[0340] - Indicator indicating whether ng-en-dc is supported

[0341] - Indicator indicating whether eventB2 is supported

[0342] -NR frequency band information supported by the terminal in (NG)en-dc

[0343] -Indicator indicating whether there are multiple CRPs available per E-UTRAN frequency

[0344] - Indicator indicating whether to support starting multiple timers per E-UTRAN frequency

[0345] - An indicator indicating whether there are multiple CRPs available per RAT frequency

[0346] - Indicator indicating whether to support starting multiple timers per RAT frequency

[0347] In operation 1j-15, the base station 1j-02 may send an RRC connection release message to the terminal 1j-01 so that the terminal 1j-01 in the RRC connection mode switches to the RRC idle mode or the RRC inactive mode. The RRC connection release message may include a first CRP regarding the first RAT, a second CRP regarding the first RAT (preferentially used for (NG) EN-DC), a CRP regarding the second RAT, a T320 timer value, and a value of a new timer (e.g., Txxx) applicable to the second CRP regarding the first RAT. For example, the above information may be included in the idleModeMobilityControlInfo information element, and the idleModeMobilityControlInfo information element may be included in the RRC connection release message. According to an embodiment of the present disclosure, the first RAT may indicate EUTRA, and according to an embodiment of the present disclosure, the second RAT may indicate other RATs other than EUTRA (e.g., NR, UTRA-FDD, UTRA-TDD, CDMA2000). In the RRC connection release message according to an embodiment of the present disclosure, for the first RAT, each E-UTRAN frequency may include two CRPs; and for the second RAT, each frequency may include one CRP, and two timer values ​​may be included for the E-UTRAN frequency. When the RRC connection release message includes the first CRP for the first RAT and / or the second CRP for the first RAT and / or the CRP for the second RAT, the terminal 1j-01 may store the first CRP and / or the second CRP and / or the CRP. In the above embodiment of the present disclosure, the CRP may indicate the priority value of each frequency for each RAT. When the T320 timer value is included in the RRC connection release message, the terminal 1j-01 may configure the T320 timer value to be the value of the T320 timer to run the T320 timer. The T320 timer may be applied to the first CRP for the first RAT and the first CRP for the second RAT. When the T320 timer expires, the terminal 1j-01 may discard the first CRP for the first RAT and the first CRP for the second RAT configured via the RRC connection release message. That is, the T320 timer can be applied to the first CRP regarding the first RAT and the first CRP regarding the second RAT. When the value of the new timer (e.g., Txxx) is included in the RRC connection release message, the terminal can start the Txxx timer by configuring the Txxx time value. The Txxx timer can be applied to the second CRP regarding the first RAT. When the Txxx timer expires, the terminal 1j-01 can discard the second CRP regarding the first RAT configured via the RRC connection release message. That is, the Txxx timer can be applied to the second CRP regarding the first RAT.

[0348] In operation 1j-20, terminal 1j-01 that has switched to RRC idle mode or RRC inactive mode can perform a cell selection process.

[0349] In operation 1j-25, the terminal 1j-01 may receive system information from the cell in which it has camped through cell selection. The system information may include parameters for cell reselection. For example, the following parameters may be included:

[0350] - CRP information about the first RAT: SIB3 and SIB5

[0351] - The first CRP (legacy CRP) and the second CRP (CRP for EN-DC) of the serving frequency may be included in SIB3.

[0352] - The first CRP and the second CRP for each first RAT inter-frequency may be included in SIB5.

[0353] -CRP information about the second RAT: SIB6, SIB7, SIB8, SIB24

[0354] - A first CRP for each frequency in the second RAT. For example, a CRP for each UTRA frequency may be included in SIB6, and a CRP for each NR frequency may be included in SIB24.

[0355] For convenience of description, it will be described that in the system information according to the embodiment of the present disclosure, for the first RAT, each E-UTRAN frequency may include two CRPs, and for the second RAT, each frequency may include one CRP.

[0356] In operation 1j-30, terminal 1j-01 may perform a cell reselection evaluation process. Terminal 1j-01 may perform a cell reselection evaluation process on the EUTRA frequencies and RAT inter-frequencies broadcast in the provided frequency priority configuration information and the provided system information (the UE should only perform cell reselection evaluation on the E-UTRAN frequencies and RAT inter-frequencies given in the system information and for which the UE has a priority provided). The cell reselection evaluation process may indicate the following series of processes.

[0357] - Reselect priority processing

[0358] -Measurement rules for cell reselection

[0359] -Cell reselection criteria

[0360] The reselection priority processing can be determined based on the capabilities of the terminal 1j-01 in RRC idle mode or RRC inactive mode, the frequency priority configuration information about the first RAT and the frequency priority configuration information about the second RAT in the RRC connection release message received in operation 1j-15, the T320 time value, and the Txxx time value.

[0361] -When the Txxx timer is started, and the terminal 1j-01 is a terminal with (NG) EN_DC capability and NR is enabled, or the terminal 1j-01 is a terminal with (NG) EN-DC capability and NR is enabled and two CRPs are available for each E-UTRAN frequency (that is, when the terminal can select and apply one of the two CRPs for each E-UTRAN frequency), the terminal 1j-01 can apply the frequency priority configuration information by applying the second CRP about the first RAT included in the RRC connection release message received in operation 1j-15 to the current serving frequency and the E-UTRAN inter-frequency. The above operation can be performed regardless of the activation of the T320 timer.

[0362] -When the Txxx timer is not running or expires and the terminal 1j-01 is a terminal with (NG) EN_DC capability and NR is enabled, or the terminal 1j-01 is a terminal with (NG) EN-DC capability and NR is enabled and the second CRP in SIB3 / SIB5 is applicable, the terminal 1j-01 can apply the frequency priority configuration information by applying the second CRP included in the SIB3 received in operation 1j-25 to the current serving frequency, and apply the frequency priority configuration information by applying the second CRP included in the SIB5 received in operation 1j-25 to the E-UTRAN inter-frequency. The above operation can be performed regardless of the activation of the T320 timer.

[0363] -When the T320 timer is started and NR is disabled or the terminal 1j-01 cannot select and apply one of the two CRPs for each E-UTRAN frequency, the terminal 1j-01 can apply the frequency priority configuration information by applying the first CRP regarding the first RAT included in the RRC connection release message received in operation 1j-15 to the current serving frequency and the E-UTRAN inter-frequency.

[0364] -When the T320 timer is started, the terminal 1j-01 may apply the frequency priority configuration information by applying the CRP about the second RAT included in the RRC connection release message received in operation 1j-15 to the second RAT.

[0365] -When the T320 timer is not running or expires, the terminal 1j-01 may apply the frequency priority configuration information included in the system information to the second RAT. Here, when NR is disabled or the terminal 1j-01 cannot select and apply one of the two CRPs for each E-UTRAN frequency, the terminal 1j-01 may apply the frequency priority configuration information by applying the first CRP included in the SIB3 received in operation 1j-25 to the current serving frequency, and apply the frequency priority configuration information by applying the first CRP included in the SIB5 received in 1j-25 to the E-UTRAN inter-frequency. The terminal 1j-01 may apply the frequency priority configuration information by applying the first CRP included in the system information received in operation 1j-25 to the first RAT.

[0366] For some reasons or to minimize battery consumption, the terminal 1j-01 may perform neighbor cell measurement by applying frequency priority based on the following measurement rules. This may be the same as the above-mentioned embodiment of the present disclosure.

[0367] Terminal 1j-01 may apply different cell reselection evaluation criteria according to frequency priority. This may be the same as the above-mentioned embodiment of the present disclosure.

[0368] In operation 1j-35, the terminal 1j-01 in RRC idle mode or RRC inactive mode can reselect a new cell 1j-03 through operation 1j-30.

[0369] In operation 1j-40, the terminal 1j-01 may obtain system information including cell reselection parameters from the reselected cell 1j-03.

[0370] In operation 1j-45, when the second CRP about the first RAT is included in the received system information, the terminal 1j-01 may perform the above-mentioned operation 1j-30 to perform the cell reselection process. When the second CRP about the first RAT is not included in the system information received in operation 1j-40, when the T320 timer is started, the terminal 1j-01 may apply the frequency priority configuration information and perform the cell reselection process by applying the first CRP for each frequency in each RAT included in the RRC connection release message received in operation 1j-15. Here, the terminal 1j-01 may perform at least one of the following operations.

[0371] -When starting the Txxx timer, continue to start the Txxx timer

[0372] - Stop the Txxx timer and delete the second CRP for the first RAT included in the RRC Connection Release message

[0373] - Stop the Txxx timer; and when the second CRP is included in the SIB3 or SIB5 broadcasted by the newly selected cell later, restart the Txxx timer

[0374] When the second CRP regarding the first RAT is not included in the system information received in operation 1j-40 and the T320 timer is not running or expired, the terminal 1j-01 can determine the frequency priority and perform the cell reselection process by applying the first CRP for each frequency in each RAT included in the RRC connection release message received in operation 1j-40.

[0375] In the embodiments of the present disclosure, for the convenience of description, (NG) EN-DC is described as an example. However, the embodiments of the present disclosure are not limited to being applied to (NG) EN-DC, but can also be applied to NE-DC or NR-DC based on the same principle.

[0376] Figure 1K is a block diagram showing an internal structure of a terminal according to an embodiment of the present disclosure.

[0377] refer to Figure 1K , the terminal may include a radio frequency (RF) processor 1k-10, a baseband processor 1k-20, a memory 1k-30 and a controller 1k-40.

[0378] The RF processor 1k-10 performs functions of sending or receiving signals via a wireless channel, such as signal band conversion, amplification, etc. That is, the RF processor 1k-10 can up-convert the baseband signal provided by the baseband processor 1k-20 into an RF band signal and send the RF band signal via an antenna, and down-convert the RF band signal received via the antenna into a baseband signal. For example, the RF processor 1k-10 may include a transmit filter, a receive filter, an amplifier, a mixer, an oscillator, a digital-to-analog converter (DAC), an analog-to-digital converter (ADC), etc. Although in Figure 1K Only one antenna is shown in the figure, but the terminal may include multiple antennas. In addition, the RF processor 1k-10 may include multiple RF chains. In addition, the RF processor 1k-10 may perform beamforming. For beamforming, the RF processor 1k-10 may adjust the phase and size of each signal sent or received via multiple antennas or antenna elements. Moreover, the RF processor 1k-10 may perform multiple-input multiple-output (MIMO) and may receive several layers when performing MIMO operation.

[0379] The baseband processor 1k-20 performs the conversion function between the baseband signal and the bit string according to the physical layer specification of the system. For example, during data transmission, the baseband processor 1k-20 may encode and modulate the transmission bit string to generate complex symbols. In addition, during data reception, the baseband processor 1k-20 may recover the received bit string by demodulating and decoding the baseband signal provided by the RF processor 1k-10. For example, when the OFDM method is used, during data transmission, the baseband processor 1k-20 may generate complex symbols by encoding and modulating the transmission bit string, and map the complex symbols to subcarriers, and then form OFDM symbols through inverse fast Fourier transform (IFFT) operation and cyclic prefix (CP) insertion. In addition, during data reception, the baseband processor 1k-20 may divide the baseband signal provided by the RF processor 1k-10 into OFDM symbol units, and recover the signal mapped to the subcarrier by fast Fourier transform (FFT), and recover the received bit string by demodulation and decoding.

[0380] As described above, the baseband processor 1k-20 and the RF processor 1k-10 send and receive signals. Therefore, the baseband processor 1k-20 and the RF processor 1k-10 may be referred to as a transmitter, a receiver, a transceiver, or a communicator. In addition, at least one of the baseband processor 1k-20 or the RF processor 1k-10 may include a plurality of communication modules to support a plurality of different RATs. In addition, at least one of the baseband processor 1k-20 or the RF processor 1k-10 may include communication modules different from each other to process signals of different frequency bands from each other. For example, different radio access technologies may include a wireless local area network (LAN) (e.g., IEEE802.11), a cellular network (e.g., LTE), and the like. Moreover, different frequency bands may include ultra-high frequency (SHF) bands (e.g., 2.NRHz, NRHz), millimeter (mm) wave (e.g., 60GHz) bands.

[0381] The memory 1k-30 may store data such as basic programs, applications, configuration information, etc. for terminal operation. In particular, the memory 1k-30 may store information related to a second access node that performs wireless communication by using a second RAT. In addition, the memory 1k-30 provides stored data according to a request from the controller 1k-40.

[0382] The controller 1k-40 controls the overall operation of the terminal. For example, the controller 1k-40 may control the terminal so that the terminal receives the information required for reselecting a cell, and may control the components of the terminal so that it determines the CRP for each RAT based on the received information and performs a process for reselecting a cell. For example, the controller 1k-40 sends or receives a signal via the baseband processor 1k-20 and the RF processor 1k-10. In addition, the controller 1k-40 records data to the memory 1k-30 and reads data from the memory 1k-30. To this end, the controller 1k-40 may include at least one processor. For example, the controller 1k-40 may include a communicator processor (CP) that performs communication control and an application processor (AP) that controls an upper layer such as an application.

[0383] Figure 1L is a block diagram showing the configuration of an NR base station according to an embodiment of the present disclosure.

[0384] like Figure 1L As shown, the NR base station includes an RF processor 1L-10, a baseband processor 1L-20, a backhaul communicator 1L-30, a memory 1L-40 and a controller 1L-50.

[0385] The RF processor 1L-10 performs functions of sending or receiving signals via a wireless channel, such as signal band conversion, amplification, etc. That is, the RF processor 1L-10 can up-convert the baseband signal provided by the baseband processor 1L-20 into an RF band signal and transmit the RF band signal via an antenna, and down-convert the RF band signal received via the antenna into a baseband signal. For example, the RF processor 1L-10 may include a transmission filter, a reception filter, an amplifier, a mixer, an oscillator, a DAC, an ADC, etc. Although in Figure 1L Only one antenna is shown in the figure, but the first access node may include multiple antennas. Moreover, the RF processor 1L-10 may include multiple RF chains. In addition, the RF processor 1L-10 may perform beamforming. For beamforming, the RF processor 1L-10 may adjust the phase and size of each signal sent or received via multiple antennas or antenna elements. The RF processor 1L-10 may perform MIMO operations downward by sending at least one layer.

[0386] The baseband processor 1L-20 performs a conversion function between a baseband signal and a bit string according to the physical layer standard of the first RAT. For example, during data transmission, the baseband processor 1L-20 may encode and modulate the transmission bit string to generate a complex symbol. In addition, during data reception, the baseband processor 1L-20 may recover the received bit string by demodulating and decoding the baseband signal provided by the RF processor 1L-10. For example, when using the OFDM method, for data transmission, the baseband processor 1L-20 may generate a complex symbol by encoding and modulating the transmission bit string, and map the complex symbol to a subcarrier, and then compose an OFDM symbol through an IFFT operation and CP insertion. In addition, for data reception, the baseband processor 1L-20 may divide the baseband signal provided by the RF processor 1L-10 into units of OFDM symbols, and recover the signal mapped to the subcarrier through an FFT operation, and recover the received bit string by demodulating and decoding the signal. As described above, the baseband processor 1L-20 and the RF processor 1L-10 send and receive signals. Therefore, the baseband processor 1L-20 and the RF processor 1L-10 may be referred to as a transmitter, a receiver, a transceiver, a communicator, or a wireless communicator.

[0387] The backhaul communicator 1L-30 provides an interface for performing communication with other nodes in the network. That is, the backhaul communicator 1L-30 converts a bit string sent from the main base station to another node such as a sub-base station, a core network, etc. into a physical signal, and converts a physical signal received from another node into a bit string.

[0388] The memory 1L-40 may store data such as basic programs, application programs, configuration information, etc. for the operation of the main base station. In particular, the memory 1L-40 may store information about bearers allocated to connection terminals, measurement results reported by connection terminals, etc. In addition, the memory 1L-40 may provide multiple connections to the terminal, or store information used as a criterion for determining whether to stop a connection. In addition, the memory 1L-40 provides stored data according to a request from the controller 1L-50.

[0389] The controller 1L-50 can control the overall operation of the main base station. For example, the base station according to the embodiment of the present disclosure can control the terminal to perform the above process to provide information for cell reselection by the terminal. For example, the controller 1L-50 sends or receives a signal via the baseband processor 1L-20 and the RF processor 1L-10 or via the backhaul communicator 1L-30. In addition, the controller 1L-50 can record data to the storage device 1L-40 and read data from the storage device 1L-40. To this end, the controller 1L-50 may include at least one processor.

[0390] The methods according to the claims or the specification of the present disclosure may be implemented in the form of hardware, software, or a combination of hardware and software.

[0391] When implemented as software, a computer-readable storage medium storing one or more programs (e.g., software modules) may be provided. The one or more programs stored in the computer-readable storage medium are configured to be executed by one or more processors in an electronic device. The one or more programs include instructions for directing the electronic device to perform a method according to an embodiment of the present disclosure as described in the specification or the appended claims.

[0392] The program (e.g., software module or software) may be stored in random access memory (RAM) or non-volatile memory including flash memory, read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), magnetic disk storage, compact disc ROM (CD-ROM), digital versatile disk (DVD), other types of optical storage, or magnetic cassettes. Alternatively, the program may be stored in a storage system that includes a combination of some or all of the storage devices mentioned above. In addition, each storage device may include multiple.

[0393] The program may also be stored in an attachable memory accessible via a communication network such as the Internet, an intranet, a local area network (LAN), a wide LAN (WLAN), and a storage area network (SAN), or a combination thereof. Such a memory may be connected to an electronic device executing an embodiment of the present disclosure via an external port. Other storage devices on the communication network may also be connected to an electronic device executing an embodiment of the present disclosure.

[0394] In the present disclosure, the term "computer program product" or "computer-readable medium" is used to refer to a general term such as a memory, a hard disk installed in a hard disk drive, and a signal. When performing unicast vehicle communication according to the present disclosure, these "computer program products" or "computer-readable recording media" refer to means for providing a method for performing L3 filtering by a receiving terminal and a method for transmitting L3 filtering measurement results by a receiving terminal to a transmitting terminal.

[0395] According to an embodiment of the present disclosure, an apparatus and method for efficiently providing a service in a wireless communication system are provided.

[0396] In the above-mentioned embodiments of the present disclosure, according to the embodiments of the present disclosure, the elements included in the present disclosure are expressed in singular or plural form. However, the singular or plural form is appropriately selected for the convenience of explanation, and the present disclosure is not limited thereto. In this way, the element expressed in plural form may also be configured as a single element, and the element expressed in singular form may also be configured as multiple elements.

[0397] Although the present disclosure has been described using various embodiments, various changes and modifications may occur to those skilled in the art. The present disclosure is intended to encompass such changes and modifications as fall within the scope of the appended claims.

Claims

1. A method performed by a terminal in a wireless communication system, the method comprising: Sending capability information of the terminal to the first cell, where the capability information of the terminal includes information about whether the terminal supports multiple cell reselection priorities CRP; Based on the capability information of the terminal, receiving a radio resource control RRC connection release message from the first cell, the RRC connection release message including a parameter indicating application of an alternative CRP broadcast in system information; Based on the RRC connection release message, switching to an RRC idle mode or an RRC inactive mode, and camping on a second cell; receiving, from the second cell, system information including a first CRP and a second CRP; as well as Based on the parameters and the system information, a second CRP for Evolved Universal Mobile Telecommunications System UMTS Terrestrial Radio Access Network EUTRAN frequencies is applied.

2. The method according to claim 1, further comprising: In a case where the RRC connection release message includes a timer value, the timer is started based on the timer value.

3. The method according to claim 1, wherein: The system information is included in a system information block SIB3 or SIB5.

4. The method according to claim 3, wherein: The SIB3 includes information about a second CRP for a serving frequency associated with the second cell.

5. The method according to claim 3, wherein: The SIB5 includes information about the second CRP for each EUTRAN frequency.

6. A terminal in a wireless communication system, the terminal comprising: Transceiver; as well as at least one processor, connected to the transceiver and configured to: controlling the transceiver to send capability information of the terminal to the first cell, wherein the capability information of the terminal includes information on whether the terminal supports multiple cell reselection priorities CRP, controlling the transceiver to receive a radio resource control RRC connection release message from the first cell based on the capability information of the terminal, wherein the RRC connection release message includes a parameter indicating application of an alternative CRP broadcast in system information, Based on the RRC connection release message, switching to an RRC idle mode or an RRC inactive mode, and camping on a second cell, controlling the transceiver to receive system information including a first CRP and a second CRP from the second cell, and Based on the parameters and the system information, a second CRP for an Evolved Universal Mobile Telecommunications System (UMTS) Terrestrial Radio Access Network (EUTRAN) frequency is applied.

7. The terminal according to claim 6, wherein: The at least one processor is further configured to start a timer if the RRC connection release message includes a value of the timer.

8. The terminal according to claim 6, wherein: The system information is included in a system information block SIB3 or SIB5.

9. The terminal according to claim 8, wherein: The SIB3 includes information about a second CRP for a serving frequency associated with the second cell.

10. The terminal according to claim 8, wherein: The SIB5 includes information about the second CRP for each EUTRAN frequency.

11. A method performed by a base station associated with a first cell in a wireless communication system, the method comprising: receiving capability information of the terminal from the terminal, where the capability information of the terminal includes information on whether the terminal supports multiple cell reselection priorities CRP; as well as Based on the capability information of the terminal, sending a radio resource control RRC connection release message to the terminal, the RRC connection release message including a parameter indicating application of an alternative CRP broadcast in system information; as well as The terminal switches to RRC idle mode or RRC inactive mode based on the RRC connection release message, resides on a second cell, receives system information including a first CRP and a second CRP from the second cell, and applies a second CRP for an Evolved Universal Mobile Telecommunications System (UMTS) Terrestrial Radio Access Network EUTRAN frequency based on the parameters and the system information.

12. The method according to claim 11, wherein: In a case where the RRC connection release message includes a timer value, the terminal starts the timer based on the timer value.

13. The method according to claim 11, wherein: The system information is included in a system information block SIB3 or SIB5, wherein the SIB3 includes information about a second CRP for a serving frequency associated with the second cell, The SIB5 includes information about the second CRP of each EUTRAN frequency.

14. A base station associated with a first cell in a wireless communication system, the base station comprising: Transceiver; as well as at least one processor, connected to the transceiver and configured to: controlling the transceiver to receive capability information of the terminal from the terminal, wherein the capability information of the terminal includes information on whether the terminal supports multiple cell reselection priorities CRP, controlling the transceiver to send a radio resource control RRC connection release message to the terminal based on the capability information of the terminal, wherein the RRC connection release message includes a parameter indicating application of an alternative CRP broadcast in system information, The terminal switches to RRC idle mode or RRC inactive mode based on the RRC connection release message, resides on a second cell, receives system information including a first CRP and a second CRP from the second cell, and applies a second CRP for an Evolved Universal Mobile Telecommunications System UMTS Terrestrial Radio Access Network EUTRAN frequency based on the parameters and the system information.

15. The base station according to claim 14, wherein: The system information is included in a system information block SIB3 or SIB5, wherein the SIB3 includes information about a second CRP for a serving frequency associated with the second cell, The SIB5 includes information about the second CRP of each EUTRAN frequency.

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