Method and apparatus for configuring frequency measurements for a non-connected mode terminal and for performing frequency measurements

Abstract

The present invention provides a frequency measurement configuration method and a method and apparatus for performing frequency measurement for a non-connected mode terminal in a next-generation mobile communication system. [Solution] The present invention relates to a communication technique and system for converging a 5G communication system with IoT technology to support a higher data transmission rate after the 4G system. The present invention is applied to intelligent services (e.g., smart homes, smart buildings, smart cities, smart or connected cars, healthcare, digital education, retail, security, and safety-related services, etc.) based on 5G communication technology and IoT-related technology.

Description

[Technical Field]

[0001] The present invention relates to a method for setting frequency measurement for a non-connected mode terminal in a next generation mobile communication system, and a method and apparatus for performing frequency measurement. [Background technology]

[0002] Efforts are underway to develop improved 5G or pre-5G communication systems to meet the increasing demand for wireless data traffic following the commercialization of 4G communication systems. For this reason, 5G or pre-5G communication systems are referred to as beyond-4G or post-LTE systems. To achieve high data transmission rates, implementation of 5G communication systems in ultra-high frequency (mm Wave) bands (e.g., the 60 GHz band) is being considered. To mitigate propagation path loss and increase transmission distances in ultra-high frequency bands, technologies such as beamforming, massive array multiple input / output (massive MIMO), full dimensional MIMO (FD-MIMO), array antennas, analog beamforming, and largescale antennas are being discussed for 5G communication systems. Furthermore, to improve the system's network, technological developments are being made in the 5G communication system, such as advanced small cells, cloud radio access networks (cloud RAN), ultra-dense networks, device to device communication (D2D), wireless backhaul, moving networks, cooperative communication, CoMP (Coordinated Multi-Point), and interference cancellation.Other advanced adaptive modulation and coding (ACM) technologies being developed for 5G systems include hybrid FSK and QAM modulation (FQAM) and sliding window superposition coding (SWSC), as well as advanced access technologies such as filter bank multi-carrier (FBMC), non-orthogonal multiple access (NOMA), and sparse code multiple access (SCMA).

[0003] Meanwhile, the Internet, a human-centered network where humans generate and consume information, is evolving into the Internet of Things (IoT), a network where distributed entities such as things exchange and process information without human intervention. IoE (Internet of Everything) technology, which combines IoT technology with big data processing technologies such as those connected to cloud servers, is also emerging. To realize the IoT, technological elements such as sensing technology, wired and wireless communication and network infrastructure, service interface technology, and security technology are required. Recently, research has focused on sensor networks for connecting things, M2M (Machine to Machine), and MTC (Machine Type Communication). In an IoT environment, intelligent IT (Internet Technology) services are provided that collect and analyze data generated by connected things and create new value in people's lives. Through the convergence and integration of existing IT (information technology) with various industries, IoT is being applied in areas such as smart homes, smart buildings, smart cities, smart or connected cars, smart grids, healthcare, smart home appliances, and advanced medical services.

[0004] As such, various attempts are being made to apply 5G communication systems to IoT networks. For example, technologies such as sensor networks, MTC (Machine Type Communication), and M2M (Machine to Machine) communication are being implemented using beamforming, MIMO, and array antennas. Furthermore, the application of cloud radio access networks (RANs) as the aforementioned big data processing technology is also seen as an example of the convergence between 5G and IoT technologies.

[0005] To support services with high data transmission rates and low transmission delays in next-generation mobile communication systems, base stations must quickly configure carrier aggregation (CA) and dual connectivity (DC) technologies in terminals. However, configuring these technologies in terminals requires frequency measurement results for the terminal. Summary of the Invention [Problem to be solved by the invention]

[0006] The present invention has been made in view of the above-mentioned conventional techniques, and an object of the present invention is to provide a terminal and a base station that can quickly report frequency measurement results, and an operation method thereof. [Means for solving the problem]

[0007] In order to achieve the above object, a method performed by a terminal in a communication system according to one aspect of the present invention includes the steps of: checking whether a first frequency list is included in first information received by an RRC (radio resource control) release message; if the first frequency list is included in the first information, performing measurements in RRC_IDLE mode or RRC_INACTIVE mode based on the first frequency list; and if the first frequency list is not included in the first information, performing measurements in RRC_IDLE mode or RRC_INACTIVE mode based on a second frequency list included in second information received by a system information block (SIB), wherein the measurements are performed based on synchronization signal block (SSB) configuration information included in the first information or the second information.

[0008] In order to achieve the above object, a terminal in a communication system according to one aspect of the present invention comprises a transceiver unit and a control unit, wherein the control unit is configured to check whether a first frequency list is included in first information received by an RRC (radio resource control) release message, and if the first frequency list is included in the first information, perform measurements in RRC_IDLE mode or RRC_INACTIVE mode based on the first frequency list, and if the first frequency list is not included in the first information, perform measurements in RRC_IDLE mode or RRC_INACTIVE mode based on a second frequency list included in second information received by a system information block (SIB), and the measurements are performed based on synchronization signal block (SSB) setting information included in the first information or the second information.

[0009] In order to achieve the above object, a method performed by a base station in a communication system according to one aspect of the present invention includes the steps of: transmitting first information by an RRC (radio resource control) release message; and transmitting second information by a system information block (SIB), wherein if a first frequency list is included in the first information, a measurement is performed by a terminal in an RRC_IDLE mode or an RRC_INACTIVE mode based on the first frequency list; and if the first frequency list is not included in the first information, a measurement is performed by the terminal in an RRC_IDLE mode or an RRC_INACTIVE mode based on a second frequency list included in second information received by the SIB, and the measurement is performed based on synchronization signal block (SSB) setting information included in the first information or the second information.

[0010] In order to achieve the above object, a base station in a communication system according to one aspect of the present invention comprises a transceiver unit and a control unit, wherein the control unit is configured to transmit first information by an RRC (radio resource control) release message and to transmit second information by a system information block (SIB), and when a first frequency list is included in the first information, a measurement is performed by a terminal in an RRC_IDLE mode or an RRC_INACTIVE mode based on the first frequency list, and when the first frequency list is not included in the first information, a measurement is performed by the terminal in an RRC_IDLE mode or an RRC_INACTIVE mode based on a second frequency list included in second information received by the SIB, and the measurement is performed based on synchronization signal block (SSB) setting information included in the first information or the second information. [Effects of the Invention]

[0011] According to the present invention, a method is proposed for a terminal in an RRC idle mode or an RRC inactive mode in a next-generation mobile communication system to quickly report a surrounding frequency measurement result to a base station, thereby enabling the base station to quickly configure a frequency aggregation technology or a dual connectivity technology in the terminal. Specifically, when the terminal releases its connection with the network, the base station can configure configuration information for frequency measurement in an RRC idle mode or an RRC inactive mode, for the terminal having terminal capability for frequency measurement, using an RRC message. While moving in the RRC idle mode or the RRC inactive mode and performing a cell selection or reselection procedure, the terminal can perform frequency measurement based on the frequency measurement configuration information configured in the RRC message or system information of the serving cell on which it camped during the cell reselection procedure. Then, when the terminal establishes a connection with the network, the base station can quickly configure the terminal with a carrier aggregation technology (CA) or a dual connectivity technology (DC) by immediately reporting the frequency measurement result.

[0012] The above and other aspects, features, and advantages of particular embodiments of the present invention will become more apparent from the following detailed description taken in conjunction with the drawings. [Brief explanation of the drawings]

[0013] [Figure 1] 1 is a diagram showing the configuration of an LTE system according to one embodiment of the present invention. [Figure 2] FIG. 1 is a diagram illustrating a radio protocol configuration of an LTE system according to an embodiment of the present invention. [Figure 3] 1 is a diagram showing the configuration of a next-generation mobile communication system according to one embodiment of the present invention. [Figure 4] 1 is a diagram illustrating a wireless protocol configuration of a next-generation mobile communication system according to one embodiment of the present invention. [Figure 5]FIG. 10 is a diagram illustrating a procedure for a terminal in a next-generation mobile communication system according to an embodiment of the present invention to switch from an RRC idle mode or an RRC INACTIVE mode to an RRC connected mode and configure a carrier aggregation technology. [Figure 6] FIG. 10 is a diagram illustrating a first embodiment in which a terminal in a next-generation mobile communication system according to an embodiment of the present invention performs early frequency measurement in RRC idle mode or RRC inactive mode and reports a fast frequency measurement result (fast measurement report). [Figure 7] FIG. 10 is a diagram illustrating a second embodiment in which a terminal in a next-generation mobile communication system according to an embodiment of the present invention performs early frequency measurement in RRC idle mode or RRC inactive mode and reports a fast frequency measurement result (fast measurement report). [Figure 8] 10 is a diagram illustrating a specific signal configuration when a terminal according to an embodiment of the present invention performs RRC idle mode or RRC inactive mode frequency measurement on an LTE frequency. [Figure 9] A diagram showing a specific signal configuration when a terminal according to one embodiment of the present invention performs RRC idle mode or RRC inactive mode frequency measurement on an NR frequency. [Figure 10] A diagram showing a specific signal configuration when a terminal according to one embodiment of the present invention performs RRC idle mode or RRC inactive mode frequency measurement on an NR frequency. [Figure 11] 1 is a diagram illustrating a method for a terminal to perform RRC idle mode or RRC inactive mode frequency measurement in a network synchronized between different frequencies or cells according to an embodiment of the present invention. [Figure 12]1 is a diagram illustrating a problem that occurs when a terminal performs RRC idle mode or RRC inactive mode frequency measurement in a network that is not synchronized between different frequencies or cells according to an embodiment of the present invention. [Figure 13] FIG. 2 illustrates a first example of an efficient RRC idle mode or RRC inactive mode frequency measurement method according to an embodiment of the present invention. [Figure 14] FIG. 2 illustrates a second example of an efficient RRC idle mode or RRC inactive mode frequency measurement method according to an embodiment of the present invention. [Figure 15] FIG. 10 illustrates a third example of an efficient RRC idle mode or RRC inactive mode frequency measurement method according to an embodiment of the present invention. [Figure 16] FIG. 4 is a diagram illustrating a fourth example of an efficient RRC idle mode or RRC inactive mode frequency measurement method according to an embodiment of the present invention. [Figure 17] 1 is a diagram illustrating a method for a terminal to perform RRC idle mode or RRC inactive mode frequency measurement in a network that is not synchronized between different frequencies or cells according to an embodiment of the present invention. [Figure 18] 10 is a diagram illustrating a terminal operation for performing RRC idle mode or RRC inactive mode frequency measurement and reporting the measurement result according to one embodiment of the present invention. [Figure 19] FIG. 2 is a diagram illustrating a configuration of a terminal according to an embodiment of the present invention. [Figure 20] FIG. 2 is a diagram showing a block configuration of a TRP in a wireless communication system according to one embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0014] Before proceeding with the detailed description below, it is necessary to define certain words and phrases used throughout this specification. The terms "include" and "comprise," as well as derivatives thereof, refer to inclusion without limitation. The term "or" is inclusive, meaning and / or. The term "associated with," as well as derivatives thereof, means "include," "included within," "interconnect with," "contain," "be contained within," "connect to or with," "couple to or with," "be communicable with," "cooperate with," "interleave with," "juxtapose with," "be proximate to," "be bound to or with," "have," "have a property of," "have a relationship to or with," and the like. The term "controller" means any device, system, or part thereof that controls at least one operation. Such a controller may be embodied in hardware, or a combination of hardware and software, and / or firmware. The functionality associated with any particular controller may be centralized or distributed, whether locally or remotely.

[0015] Furthermore, the various functions described below are implemented as computer-readable program code and are embodied in or supported by one or more computer programs embodied in a computer-readable recording medium. The terms "application" and "program" refer to one or more computer programs, software components, instruction sets, procedures, functions, objects, classes, instances, associated data, or portions thereof configured for implementation in suitable computer-readable program code. The phrase "computer-readable recording medium" includes any type of medium accessible by a computer, such as read-only memory (ROM), random access memory (RAM), hard disk drive, compact disc (CD), digital video disc (DVD), or any type of memory. "Non-transitory" computer-readable recording medium excludes communication links that transmit wired, wireless, optical, transient electrical, or other signals. Non-transitory computer-readable recording medium includes media on which data is permanently stored and media on which data is stored and subsequently overwritten, such as rewritable optical disks or erasable memory devices.

[0016] Definitions for other specific words and phrases are provided throughout this specification, and one of ordinary skill in the art should understand that in many, if not most, cases, such definitions apply to not only the prior art but also future uses of such defined words and phrases.

[0017] 1 to 20 described below, and various embodiments used herein to explain the principles of the present invention, are for illustrative purposes only and should not be construed as limiting the scope of the present invention in any way. Those of ordinary skill in the art will understand that the principles of the present invention may be embodied in any suitably arranged system or device.

[0018] The following description, with reference to the drawings, is provided to facilitate a comprehensive understanding of various embodiments of the present invention, as defined by the claims and their equivalents. Although various specific details are included herein to facilitate understanding, these details should be considered merely as examples. Therefore, those skilled in the art will recognize that various modifications and alterations can be made to the various embodiments disclosed herein without departing from the scope and spirit of the present invention. Furthermore, for the sake of clarity and brevity, descriptions of well-known functions and configurations are omitted.

[0019] The terms and phrases used in the following description and claims are not limited to their literary meanings, but are merely used by the inventor to ensure a clear and consistent understanding of the present invention. Therefore, it should be apparent to those skilled in the art that the following description of various embodiments of the present invention is provided for illustrative purposes only, and not for the purpose of limiting the present invention as defined by the claims and their equivalents.

[0020] In the following description of the present invention, if it is determined that a detailed description of related known functions or configurations would obscure the gist of the present invention, the detailed description will be omitted. Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0021] In the following description, terms for identifying connection nodes, terms for designating network entities, terms for designating messages, terms for designating interfaces between network objects, and terms for designating various identification information are provided as examples for the sake of convenience. Therefore, this specification is not limited to the terms described below, and other terms for designating objects having equivalent technical meanings may be used.

[0022] For ease of explanation, the present invention uses terms and names defined in the 3GPP LTE (3rd Generation Partnership Project Long Term Evolution) standard. However, the present invention is not limited by the terms and names and is similarly applicable to systems based on other standards. In the present invention, the term "eNB" is used interchangeably with the term "gNB" for ease of explanation. That is, a base station described as "eNB" refers to a "gNB."

[0023] The present invention proposes a method for a terminal in an RRC idle mode or an RRC inactive mode in a next-generation mobile communication system to quickly report a surrounding frequency measurement result to a base station, thereby allowing the base station to quickly configure a frequency aggregation technology or a dual connectivity technology in the terminal. Specifically, when the terminal releases its connection with the network, the base station configures configuration information for frequency measurement in an RRC idle mode or an RRC inactive mode for the terminal capable of frequency measurement in the RRC idle mode or the RRC inactive mode using an RRC message. The terminal then moves in the RRC idle mode or the RRC inactive mode and performs a cell selection or reselection procedure, and performs frequency measurement based on the frequency measurement configuration information configured in the RRC message or system information of the camped-on serving cell in the cell reselection procedure. Then, when the terminal establishes a connection with the network, the base station promptly reports the frequency measurement result, thereby quickly configuring the terminal with a carrier aggregation technology (CA) or a dual connectivity technology (DC).

[0024] In the present invention, an RRC connected mode UE receives an RRC message (e.g., an RRCRelease message) from a base station to release the RRC connection, and when the RRC message indicates an instruction to transition to an RRC IDLE mode or an RRC inactive mode together with frequency measurement configuration information, the UE performs frequency measurement for a period or time set in the RRC idle mode or the RRC inactive mode. However, if the frequency measurement configuration information set through the RRC message does not contain information on a list of frequencies to be measured and frequency measurement configuration information for frequency measurement of an RRC idle mode or an RRC inactive mode UE is broadcast in a serving cell that is camped on while performing a cell selection or reselection procedure, the UE stores or considers the frequency measurement list based on this information and performs frequency measurement.

[0025] As described above, the terminal performs frequency measurement in RRC idle mode or RRC inactive mode. When an RRC connection with the network needs to be established, and the system information of the serving cell contains an indicator supporting RRC idle mode or RRC inactive mode frequency measurement (Early measurement), or the terminal has valid measurement results that satisfy the measurement result reporting conditions set in the frequency measurement configuration information, the terminal in RRC idle mode or RRC inactive mode transmits an indicator indicating the presence of frequency measurement results in RRC idle mode or RRC inactive mode to the base station via an RRC message (e.g., an RRCSetupComplete message or an RRCResumeComplete message). Upon receiving the indicator, the base station transmits a request message (e.g., a new RRC message or a UEInformationRequest message) to request the terminal for frequency measurement results. Upon receiving the request message, the terminal configures the frequency measurement results in a response message (e.g., a new RRC message or a UEInformationResponse message) and reports the result to the base station. The base station then promptly configures a frequency aggregation technology or dual connectivity technology for the terminal based on the measurement results.

[0026] In another method, the terminal needs to perform frequency measurement in RRC inactive mode and establish an RRC connection with the network. If there is an indicator supporting RRC idle mode or RRC inactive mode frequency measurement (Early measurement) in the system information of the serving cell, or if the terminal has valid measurement results that satisfy the measurement result reporting conditions set in the frequency measurement configuration information, when the terminal in RRC inactive mode receives an RRC message (e.g., RRCResume) from the base station including an indicator requesting frequency measurement results from the terminal, the terminal configures valid frequency measurement results, includes them in the RRC message, and reports them to the base station. Then, the base station promptly configures a frequency aggregation technology or dual connectivity technology for the terminal based on the measurement results.

[0027] The present invention proposes which configuration information should be transmitted to a terminal for battery saving and efficient signaling when a base station configures RRC idle mode or RRC inactive mode frequency measurement configuration information in the terminal, and which configuration information should be transmitted in an RRC message (e.g., an RRCRelease message) or system information.

[0028] In addition, the present invention specifically proposes how to perform frequency measurement for each frequency or cell in order to save the battery of a terminal when the terminal receives RRC idle mode or RRC inactive mode frequency measurement configuration information from an RRC message or system information, and how to apply the frequency measurement configuration information received from an RRC message or system information when performing frequency measurement.

[0029] FIG. 1 is a diagram showing the configuration of an LTE system according to an embodiment of the present invention.

[0030] 1, as shown, the radio access network of the LTE system is composed of evolved Node Bs (hereinafter referred to as MENBs, Node Bs or base stations) (1-05, 1-10, 1-15, 1-20), a mobility management entity (MME) 1-25, and a serving gateway (S-GW) 1-30. A user equipment (hereinafter referred to as UE or terminal) 1-35 is connected to an external network via the eNBs (1-05 to 1-20) and the S-GW 1-30.

[0031] In Figure 1, eNBs (1-05 to 1-20) correspond to existing Node Bs in the UMTS system. The eNBs are connected to UEs (UEs) 1-35 via radio channels and perform more complex functions than existing Node Bs. In the LTE system, all user traffic, including real-time services such as Voice over IP (VoIP) via Internet Protocol, is served via shared channels. Therefore, a scheduling device is required to collect status information such as UE buffer status, available transmit power status, and channel status, and this is the responsibility of the eNBs (1-05 to 1-20). One eNB typically controls multiple cells. To achieve a transmission speed of 100 Mbps, for example, the LTE system uses Orthogonal Frequency Division Multiplexing (OFDM) with a 20 MHz bandwidth as its radio access technology. It also applies Adaptive Modulation & Coding (AMC), which determines the modulation scheme and channel coding rate according to the channel status of the UE. The S-GW 1-30 is a device that provides data bearers and creates or deletes data bearers under the control of the MME 1-25. The MME is a device that handles various control functions as well as mobility management functions for terminals, and is connected to multiple base stations.

[0032] FIG. 2 is a diagram showing a radio protocol configuration of an LTE system according to an embodiment of the present invention.

[0033] Referring to Figure 2, the wireless protocols of the LTE system are Packet Data Convergence Protocol (PDCP) (2-05, 2-40), Radio Link Control (RLC) (2-10, 2-35), and Medium Access Control (MAC) (2-15, 2-30) in the terminal and eNB, respectively. Packet Data Convergence Protocol (PDCP) (2-05, 2-40) is responsible for operations such as IP header compression / decompression. The main functions of PDCP are summarized as follows:

[0034] -Header compression and decompression function (ROHC only) -Transfer of user data - In-sequence delivery of upper layer PDUs at PDCP re-establishment procedure for RLC AM -Reordering function (For split bearers in DC (only support for RLC AM): PDCP PDU routing for transmission and PDCP PDU reordering for reception) -Duplicate detection of lower layer SDUs at PDCP re-establishment procedure for RLC AM -Retransmission function (Retransmission of PDCP SDUs at handover and, for split bearers in DC, of ​​PDCP PDUs at PDCP data-recovery procedure, for RLC AM) -Ciphering and deciphering functions -Timer-based SDU discard function (Timer-based SDU discard in uplink)

[0035] Radio Link Control (RLC) (2-10, 2-35) reconstructs PDCP PDUs (Packet Data Units) into appropriate sizes and performs ARQ operations. The main functions of RLC are summarized as follows:

[0036] -Data transmission function (Transfer of upper layer PDUs) -ARQ function (Error Correction through ARQ(only for AM data transfer)) - Concatenation, segmentation and reassembly of RLC SDUs (only for UM and AM data transfer) -Re-segmentation of RLC data PDUs (only for AM data transfer) -Reordering of RLC data PDUs (only for UM and AM data transfer) -Duplicate detection (only for UM and AM data transfer) -Protocol error detection (only for AM data transfer) -RLC SDU deletion function (RLC SDU discard (only for UM and AM data transfer)) -RLC re-establishment function

[0037] The MAC (2-15, 2-30) is connected to multiple RLC layer devices configured in one terminal and performs the operations of multiplexing RLC PDUs into MAC PDUs and demultiplexing RLC PDUs from MAC PDUs. The main functions of the MAC are summarized as follows:

[0038] -Mapping function (Mapping between logical channels and transport channels) - Multiplexing and demultiplexing functions (Multiplexing / demultiplexing of MAC SDUs belonging to one or different logical channels into / from transport blocks (TB) delivered to / from the physical layer on transport channels) -Scheduling information reporting function -HARQ function (Error correction through HARQ) -Priority handling between logical channels of one UE -Priority handling between UEs by means of dynamic scheduling -MBMS service identification function -Transport format selection -Padding function

[0039] The physical layer PHY (2-20, 2-25) performs channel coding and modulation of upper layer data to generate OFDM symbols and transmit them to a wireless channel, or demodulates and channel decodes the OFDM symbols received through a wireless channel and transmits them to an upper layer.

[0040] FIG. 3 is a diagram showing the configuration of a next-generation mobile communication system according to one embodiment of the present invention.

[0041] 3, as shown, the radio access network of the next-generation mobile communication system (hereinafter referred to as NR or 5G) is composed of a next-generation base station (New Radio Node B, hereinafter referred to as NR gNB or NR base station) 3-10 and an NR CN (New Radio Core Network) 3-05. A user terminal (New Radio User Equipment, hereinafter referred to as NR UE or terminal) 3-15 is connected to an external network via the NR gNB 3-10 and the NR CN 3-05.

[0042] In Figure 3, the NR gNBs 3-10 correspond to the eNBs (Evolved Node Bs) in the existing LTE system. The NR gNBs connect to the NR UEs 3-15 via radio channels and provide better service than existing Node Bs. In the next-generation mobile communication system, all user traffic is served via shared channels, requiring a device to collect and schedule status information such as UE buffer status, available transmit power status, and channel status. This task is handled by the NR NBs 3-10. A single NR gNB typically controls multiple cells. To achieve ultra-high-speed data transmission compared to current LTE, the NR gNBs have a larger bandwidth than the existing maximum bandwidth and utilize Orthogonal Frequency Division Multiplexing (OFDM) as a radio access technology, adding beamforming technology. Furthermore, they employ adaptive modulation and coding (AMC), which determines the modulation scheme and channel coding rate according to the UE's channel status. The NR CN 3-05 performs functions such as mobility support, bearer configuration, and QoS configuration. The NR CN is a device that handles various control functions as well as mobility management functions for terminals and is connected to multiple base stations. In addition, the next-generation mobile communication system will also be linked to the existing LTE system, and the NR CN will be connected to the MME 3-25 via a network interface. The MME will be connected to the existing base station, eNB 3-30.

[0043] FIG. 4 is a diagram showing a radio protocol configuration of a next-generation mobile communication system according to an embodiment of the present invention.

[0044] Referring to Figure 4, the radio protocol of the next-generation mobile communication system is performed in the terminal and the NR base station by NR SDAP (4-01, 4-45), NR PDCP (4-05, 4-40), NR RLC (4-10, 4-35), and NR MAC (4-15, 4-30), respectively.

[0045] The main functions of the NR SDAP (4-01, 4-45) include some of the following functions:

[0046] -Transfer of user plane data -Mapping function of QoS flow and data bearer for uplink and downlink (mapping between a QoS flow and a DRB for both DL and UL) - QoS flow ID marking function for uplink and downlink (marking QoS flow ID in both DL and UL packets) -A function to map reflective QoS flow to data bearers for uplink SDAP PDUs (reflective QoS flow to DRB mapping for the UL SDAP PDUs).

[0047] The UE configures the SDAP layer device in an RRC message whether to use the header of the SDAP layer device or whether to use the functions of the SDAP layer device for each PDCP layer device, bearer, or logical channel. If the SDAP header is configured, the NAS reflective QoS setting 1-bit indicator (NAS reflective QoS) and AS reflective QoS setting 1-bit indicator (AS reflective QoS) in the SDAP header instruct the UE to update or reconfigure the uplink and downlink QoS flows and mapping information for data bearers. The SDAP header includes QoS flow ID information that indicates QoS. QoS information is used for data processing priority, scheduling information, etc. to support smooth service.

[0048] The main functions of the NR PDCP (4-05, 4-40) include some of the following functions:

[0049] -Header compression and decompression function (ROHC only) -Transfer of user data -In-sequence delivery of upper layer PDUs -Out-of-sequence delivery of upper layer PDUs -Reordering function (PDCP PDU reordering for reception) -Duplicate detection of lower layer SDUs -Retransmission of PDCP SDUs -Ciphering and deciphering functions -Timer-based SDU discard function (Timer-based SDU discard in uplink)

[0050] The reordering function of an NR PDCP device refers to a function of reordering PDCP PDUs received at a lower layer based on the PDCP sequence number (SN), and includes a function of transmitting data to a higher layer in the reordered order or a function of transmitting data immediately without considering the procedure, a function of recording lost PDCP PDUs by reordering the procedure, a function of reporting the status of lost PDCP PDUs to the transmitting side, and a function of requesting retransmission of lost PDCP PDUs.

[0051] The main functions of the NR RLC (4-10, 4-35) include some of the following functions:

[0052] -Data transmission function (Transfer of upper layer PDUs) -In-sequence delivery of upper layer PDUs -Out-of-sequence delivery of upper layer PDUs -ARQ function (Error Correction through ARQ) - Concatenation, segmentation and reassembly of RLC SDUs -Re-segmentation of RLC data PDUs -Reordering of RLC data PDUs -Duplicate detection -Protocol error detection -RLC SDU deletion function (RLC SDU discard) -RLC re-establishment function

[0053] The in-sequence delivery function of the NR RLC device refers to the function of delivering RLC SDUs received from a lower layer to a higher layer in sequence, and includes a function of reassembling and delivering RLC SDUs when one RLC SDU is originally divided into multiple RLC SDUs, a function of rearranging received RLC PDUs based on the RLC sequence number (SN) or PDCP sequence number (SN), a function of recording lost RLC PDUs by rearranging the procedure, a function of reporting the status of lost RLC PDUs to the transmitting side, a function of requesting retransmission of lost RLC PDUs, and a function of delivering only RLC SDUs up to the lost RLC SDU in sequence to a higher layer in sequence when a lost RLC SDU is found, or a function of delivering all RLC SDUs received before the timer is started to a higher layer in sequence when a predetermined timer expires even if a lost RLC SDU is found, or a function of delivering all RLC SDUs received up to the time when a predetermined timer expires to a higher layer in sequence even if a lost RLC SDU is found. In addition, the RLC PDUs can be processed in the order in which they are received (in the order in which they arrive, regardless of the sequence number order) and delivered to the PDCP device regardless of the order (out-of-sequence delivery). In the case of a segment, a segment stored in a buffer or received subsequently can be received and reconstructed into a complete RLC PDU, and then processed and delivered to the PDCP device. The NR RLC layer does not need to include a concatenation function; this function can be performed in the NR MAC layer or replaced by the multiplexing function of the NR MAC layer.

[0054] The out-of-sequence delivery function of the NR RLC device refers to the function of immediately delivering an RLC SDU received from a lower layer to a higher layer regardless of the procedure. It includes the function of reassembling and delivering an RLC SDU that was originally split into multiple RLC SDUs when received, and the function of storing the RLC SN or PDCP SN of the received RLC PDU, aligning the procedure, and recording lost RLC PDUs.

[0055] The NR MAC (4-15, 4-30) is connected to multiple NR RLC layer devices configured in one terminal, and the main functions of the NR MAC include some of the following functions.

[0056] -Mapping function (Mapping between logical channels and transport channels) -Multiplexing / demultiplexing of MAC SDUs -Scheduling information reporting function -HARQ function (Error correction through HARQ) -Priority handling between logical channels of one UE -Priority handling between UEs by means of dynamic scheduling -MBMS service identification function -Transport format selection -Padding function

[0057] The NR PHY layers (4-20, 4-25) perform channel coding and modulation of upper layer data, creating OFDM symbols and transmitting them over a wireless channel, or demodulating and channel decoding OFDM symbols received over a wireless channel and transmitting them to an upper layer.

[0058] In the next-generation mobile communication system, a terminal performs frequency measurement while performing a cell selection or reselection procedure in RRC idle mode or RRC inactive mode. Frequency measurement performed during a cell selection or reselection procedure refers to intra-frequency measurement or serving cell measurement for a frequency configured by a base station or broadcast in a capped cell. However, inter-frequency measurement other than intra-frequency measurement or serving cell measurement is not performed, and frequency measurement results are not separately reported to the network. However, if the base station configures RRC idle mode or RRC inactive mode frequency measurement configuration information in an RRC message (e.g., an RRCRelease message) or receives RRC idle mode or RRC inactive mode frequency measurement configuration information in system information, and if the system information of the serving cell or capped cell indicates that it supports RRC idle mode or RRC inactive mode frequency measurement configuration information, the terminal also performs an inter-frequency measurement procedure. If the terminal stores valid measurements that meet certain conditions, it will report the frequency measurements immediately when it establishes a connection with the network.

[0059] In addition, the UE can also receive frequency measurement configuration information and perform a frequency measurement procedure even in RRC connected mode as follows. The RRC connected mode frequency measurement configuration information is configured only in an RRC message (e.g., an RRCReconfiguration message), while the RRC idle mode or RRC inactive mode frequency measurement configuration information is configured in the UE in an RRC message (e.g., an RRCRelease message) or is broadcast in system information and configured in the UE. Furthermore, when the RRC idle mode or RRC inactive mode frequency measurement configuration information is configured in an RRC message (e.g., different from the information configured in system information), it configures a period value or timer value specifying a period for the UE to measure the frequency, and configures region information (e.g., frequency-specific cell identifier list information) specifying a region for the UE to measure the frequency.

[0060] The UE can also receive frequency measurement configuration information and perform a frequency measurement procedure even in the RRC connected mode as follows: When the UE transitions to the RRC connected mode through the RRC connection setup procedure after performing a cell reselection procedure to find a suitable cell and camp on it, the base station configures the RRC connected mode UE with which frequency (e.g., a frequency list) or which frequency band to measure, the procedure to perform the measurement in accordance with a priority setting for each frequency, which beam to measure, the filtering method to measure the frequency strength when measuring the frequency (e.g., L1 filtering, L2 filtering, L3 filtering, or which coefficients and calculation methods to use), which event or condition to start measurement according to when measuring the frequency, the criterion to use when comparing with the current serving cell (or the currently camped-on frequency), the event or condition to report the measured frequency result, the criterion or condition to meet when comparing with the current serving cell (or the currently camped-on frequency) to report the frequency, and the period to report the frequency measurement result. The terminal measures the frequency according to the frequency setting set by the base station and reports the frequency measurement result to the base station according to the event or condition.The base station then determines whether to apply carrier aggregation or dual connectivity to the terminal using the frequency measurement result received from the terminal.

[0061] The present invention proposes a method in which a terminal in a next-generation mobile communication system performs frequency measurement in an RRC idle mode or an RRC inactive mode before transitioning to an RRC connected mode, and when the terminal establishes a connection with a network, the terminal indicates to a base station an indicator that there is a measurement result, or the base station requests a report if there is a measurement result for the terminal, thereby entering the RRC connected mode and promptly reporting the frequency measurement result. Based on the above method, the base station promptly configures a frequency aggregation technology or a dual connectivity technology for the terminal based on the measurement result of the terminal in the RRC idle mode or the RRC inactive mode.

[0062] Specifically, when a base station transitions a UE in an RRC connected mode that has established a connection with the network to an RRC idle mode or an RRC inactive mode, the base station instructs the UE to perform frequency measurement in an RRC idle mode or an RRC inactive mode by configuring, via an RRC message, frequency information to be measured by the UE in the RRC idle mode or the RRC inactive mode, time (or period) information to be measured by the UE in the RRC idle mode or the RRC inactive mode, or area information (or cell list) to be measured by the UE in the RRC idle mode or the RRC inactive mode. In addition, the UE acquires system information of a newly capped-on cell while performing a cell reselection operation every time it moves, and performs procedures such as continuing or terminating frequency measurement in the RRC idle mode or the RRC inactive mode, extending the measurement period (e.g., restarting a timer), reporting frequency measurement results, discarding frequency measurement results, or updating frequency configuration information according to the system information.

[0063] In the present invention, bearer is meant to include SRB (Signaling Radio Bearer) and DRB (Data Radio Bearer), and UM DRB means a DRB using an RLC layer device operating in UM (Unacknowledged Mode) mode, and AM DRB means a DRB using an RLC layer device operating in AM (Acknowledged Mode) mode.

[0064] FIG. 5 is a diagram illustrating a procedure in which a terminal in a next-generation mobile communication system according to an embodiment of the present invention switches from an RRC idle mode or an RRC INACTIVE mode to an RRC connected mode and configures a carrier aggregation technology.

[0065] In Figure 5, the base station transitions the RRC connected mode UE that has established a connection with the network to the RRC idle mode or the RRC inactive mode for a predetermined reason, such as a lack of scheduling resources of the base station or the suspension of data transmission and reception with the UE for a certain period of time.

[0066] The base station sends an RRCRelease message to the terminal to instruct the terminal to transition to RRC idle mode or RRC inactive mode. According to one embodiment, the RRCRelease message includes an indicator (suspend-config) to instruct the terminal to transition to RRC inactive mode, and if the RRCRelease message does not include the indicator (suspend-config), the terminal transitions to RRC idle mode (5-05).

[0067] When a terminal that has transitioned to RRC idle mode or RRC inactive mode needs to connect to the network for a specific reason, it performs a random access procedure, receives a random access response to request RRC connection setup, and receives an RRC message to perform RRC connection setup (5-10, 5-15, 5-20, 5-25, 5-30, 5-35, 5-40).

[0068] The terminal establishes reverse transmission synchronization with the base station through a random access procedure and transmits an RRCSetupRequest message to the base station (5-25). The RRCSetupRequest message includes the terminal identifier, the reason for establishing a connection (establishmentCause), etc.

[0069] The base station transmits an RRC Setup message to the terminal to set up an RRC connection (5-30). The RRC Setup message includes at least one of configuration information for each logical channel, configuration information for each bearer, configuration information for a PDCP layer device, configuration information for an RLC layer device, and configuration information for a MAC layer device.

[0070] The RRCSetup message assigns a bearer identifier (e.g., an SRB identifier or a DRB identifier) ​​to each bearer and instructs the configuration of the PDCP layer device, RLC layer device, MAC layer device, and PHY layer device for each bearer. The RRCConnectionSetup message also configures the length of the PDCP sequence number (e.g., 12 bits or 18 bits) used in the PDCP layer device for each bearer and configures the length of the RLC sequence number (e.g., 6 bits, 12 bits, or 18 bits) used in the RLC layer device. The RRCConnectionSetup message also instructs the PDCP layer device for each bearer whether to use a header compression and decompression protocol in the uplink or downlink and whether to perform an integrity protection or verification procedure. It also instructs the PDCP layer device whether to perform an out-of-order delivery function.

[0071] After establishing the RRC connection, the terminal sends an RRCSetupComplete message to the base station (5-40). The RRCSetupComplete message includes a SERVICE REQUEST control message, in which the terminal requests the AMF or MME to establish a bearer for a specific service. The base station sends a SERVICE REQUEST message contained in the RRCConnectionSetupComplete message to the AMF or MME, and the AMF or MME determines whether to provide the service requested by the terminal.

[0072] If it is determined that the service requested by the terminal is to be provided, the AMF or MME transmits an INITIAL CONTEXT SETUP REQUEST message to the base station. The INITIAL CONTEXT SETUP REQUEST message includes information such as Quality of Service (QoS) information applied when setting up a Data Radio Bearer (DRB), security-related information applied to the DRB (e.g., security key, security algorithm), etc.

[0073] The base station transmits and receives a SecurityModeCommand message and a SecurityModeComplete message to set up security with the terminal, and when the security setting is completed, the base station transmits an RRCConnectionReconfiguration message to the terminal (5-45).

[0074] The RRCConnectionReconfiguration message assigns a bearer identifier (e.g., an SRB identifier or a DRB identifier) ​​to each bearer and instructs the configuration of the PDCP layer device, RLC layer device, MAC layer device, and PHY layer device for each bearer. The RRCConnectionReconfiguration message also configures the length (e.g., 12 bits or 18 bits) of the PDCP sequence number used in the PDCP layer device for each bearer and configures the length (e.g., 6 bits, 12 bits, or 18 bits) of the RLC sequence number used in the RLC layer device. The RRCConnectionSetup message also instructs the PDCP layer device for each bearer whether to use a header compression and decompression protocol in the uplink or downlink and whether to perform an integrity protection or verification procedure. It also instructs the PDCP layer device whether to perform an out-of-order delivery function.

[0075] The RRCConnectionReconfiguration message also includes configuration information for the DRB where user data is processed, and the terminal applies this information to configure the DRB and transmits an RRCConnectionReconfigurationComplete message to the base station (5-45). After completing the DRB configuration with the terminal, the base station transmits an INITIAL CONTEXT SETUP COMPLETE message to the AMF or MME to complete the connection (5-50).

[0076] After completing the above steps, the terminal transmits and receives data to and from the base station through the core network (5-55, 5-60). According to one embodiment, the data transmission process is roughly composed of three steps: RRC connection setup, security setup, and DRB setup. In addition, the base station transmits an RRC Connection Reconfiguration message to the terminal to update, add, or change settings for a specific reason (5-65).

[0077] The RRCConnectionReconfiguration message sets frequency configuration information that the terminal must measure (e.g., a list of frequencies that must be measured, a period for measuring the frequencies, conditions for measuring the frequencies, conditions for reporting frequencies after frequency reporting, cell identifiers for which frequencies must be reported, etc.).

[0078] According to the frequency measurement setting information, the terminal performs frequency measurement, and if a predetermined condition is met (for example, if the signal strength of a specific frequency is better than a certain standard (e.g., a threshold) or if the signal strength of the current serving cell (frequency) is less than a certain standard (e.g., a threshold)), it reports the measured frequency measurement results to the base station (5-60).

[0079] Upon receiving the frequency measurement result, the base station includes Scell ​​configuration information in an RRCReconfiguration message 5-65 based on the frequency measurement result and transmits the message to the terminal to configure a carrier aggregation technology for the terminal, or includes secondary cell group configuration information in an RRCReconfiguration message 5-65 and transmits the message to the terminal to configure a dual connectivity technology for the terminal.

[0080] When a base station configures a terminal with carrier aggregation technology, the base station transitions the configured Scell ​​to an activated, deactivated, or dormant state using a MAC CE (MAC Control Element).

[0081] The procedure for a base station to configure a carrier aggregation technology or dual connectivity technology in a terminal can be summarized as follows: First, the terminal establishes a connection with the base station, and the base station configures frequency measurement configuration information in the RRC connected mode terminal. The terminal performs frequency measurement based on the frequency measurement configuration information and reports the measurement results to the base station. Then, the base station configures configuration information for an additional Scell ​​in an RRC message to configure a carrier aggregation technology in the terminal based on the frequency measurement results of the terminal, and activates, dormants, or deactivates the Scell ​​through MAC CE. The base station also configures additional cell group (Sceondary cell group) configuration information to configure a dual connectivity technology in the terminal based on the frequency measurement results of the terminal.

[0082] When a base station configures a carrier aggregation technology or a dual connectivity technology in a terminal, the terminal must first enter an RRC connection mode to receive frequency configuration information, and then perform frequency measurement and report the result, which results in a problem that the measurement report is performed very slowly, and the carrier aggregation technology or the dual connectivity technology must be configured late. Therefore, to improve this, the present invention proposes a method for allowing a terminal to efficiently perform frequency measurement in an RRC idle mode or an RRC inactive mode and immediately report the frequency measurement result when a connection with a network is configured.

[0083] Figure 6 is a diagram showing a first embodiment in which a terminal in a next-generation mobile communication system according to one embodiment of the present invention performs early frequency measurement in RRC idle mode or RRC inactive mode and reports a fast frequency measurement result (fast measurement report).

[0084] In the first embodiment of the present invention, the base station configures a plurality of frequency measurement groups when configuring frequency measurement configuration information for the terminal to perform frequency measurement in RRC idle mode or RRC inactive mode through an RRCRelease message or system information, and the terminal performs frequency measurement in RRC idle mode or RRC inactive mode.

[0085] According to the first embodiment, a terminal that performs frequency measurement in an RRC idle mode or an RRC inactive mode and quickly reports a frequency measurement result is a terminal that corresponds to one or more of the following cases.

[0086] 1. All terminals whose terminal capability supports fast frequency measurement and fast frequency measurement result reporting methods in RRC idle mode or RRC inactive mode

[0087] 2. A terminal that receives configuration information instructing frequency measurement in RRC idle mode or RRC inactive mode when a base station in an RRC idle mode or inactive mode terminal transitions the terminal from RRC connected mode to RRC idle mode or RRC inactive mode via an RRC message. For example, a terminal that has configured frequency configuration information or a measurement period (e.g., a timer value) for performing frequency measurement in RRC idle mode or RRC inactive mode, or region configuration information (e.g., a list of cell identifiers) for performing frequency measurement.

[0088] In FIG. 6, a terminal 6-05 in RRC connected mode is transitioned to RRC idle mode or RRC inactive mode by a base station for a predetermined reason (e.g., when there is no data transmission or reception for a certain period of time) (6-15). The base station transmits an RRC message when transitioning the terminal's mode (6-10). For example, the base station transmits an RRCRelease message including an indicator (suspend-config) instructing the terminal to transition to RRC inactive mode, or an RRCRelease message without an indicator (suspend-config) to instruct the terminal to transition to RRC idle mode. The RRC message (e.g., RRCRelease message) includes first frequency configuration information to be applied when the terminal performs early frequency measurement in RRC idle mode or RRC inactive mode. The first frequency configuration information includes information on the frequency to be measured and a first timer value. The first timer indicates the period for performing frequency measurement in RRC idle mode or RRC inactive mode or the timer value (e.g., T331) for performing frequency measurement. If RRCRelease commands frequency measurement in RRC idle mode or RRC inactive mode, the timer is started and frequency measurement is performed while the timer is running, and frequency measurement is stopped when the timer expires.

[0089] When the UE performs early frequency measurement in RRC idle mode or RRC inactive mode, the conditions for starting frequency measurement include at least one of the following conditions (6-30).

[0090] 1. When the terminal receives an RRCRelease message, if the RRCRelease message includes an indicator for performing RRC idle mode or RRC inactive mode frequency measurement, and the frequency information to be measured and the period for measuring the frequency (e.g., a timer value) are set, the terminal starts the timer and performs frequency measurement according to the frequency information.

[0091] 2. When the UE receives an RRCRelease message, if the RRCRelease message includes an indicator for performing frequency measurement in RRC idle mode or RRC inactive mode, and a period for measuring the frequency (e.g., a timer value) is set but does not include frequency information to be measured, the UE starts a timer and performs a cell selection or reselection procedure to acquire system information for the serving cell on which it is camped (6-12). The system information includes second frequency configuration information to be applied when the UE performs early frequency measurement in RRC idle mode or RRC inactive mode. If frequency information to be measured in RRC idle mode or RRC inactive mode is broadcast in the system information, the UE performs frequency measurement according to this frequency information. If the UE moves to another cell and new second frequency configuration information to be measured in RRC idle mode or RRC inactive mode is broadcast in the system information of the newly camped-on cell, the UE performs frequency measurement according to the new second frequency configuration information.

[0092] As described above, the UE starts and performs frequency measurement in RRC idle mode or RRC inactive mode. When the UE moves and caps on a new cell to acquire system information, if there is no indicator supporting frequency measurement in RRC idle mode or RRC inactive mode in the system information, the UE continues to run the first timer but stops frequency measurement. When the UE moves to another cell, if there is an indicator supporting frequency measurement in RRC idle mode or RRC inactive mode in the system information of the other cell, and the first timer is running, the UE further starts frequency measurement using the first frequency configuration information set in the RRCRelease message or the second system information in the system information as proposed above. In addition, indicators indicating LTE frequency measurement support or NR frequency measurement support are defined in the system information.

[0093] If one or more of the above conditions are satisfied, the UE starts early frequency measurement in RRC idle mode or RRC inactive mode. The UE in RRC idle mode or RRC inactive mode performs frequency measurement and stores valid measurement results that correspond to certain conditions. The UE determines whether the frequency measurement results that correspond to certain conditions are valid based on the configuration information configured in the RRCRelease message or broadcast in the system information.

[0094] When the terminal needs to set up a connection with the network to send and receive data, it performs a random access procedure and sends message 3 (e.g., an RRCSetupRequest or RRCResumeRequest message) to the base station (6-35). In response to this, it receives message 4 (e.g., an RRCSetup or RRCResume message) from the base station, recognizes that the random access procedure was successful (6-40), and transitions to RRC connection mode (6-45).

[0095] If the terminal receives an indicator supporting RRC idle mode or RRC inactive mode frequency measurement or an indicator for receiving RRC idle mode or RRC inactive mode frequency measurement results in system information (e.g., SIB2) received before setting up a connection in the current cell, if the terminal has valid frequency measurement results, it sends message 5 (e.g., an RRCSetupComplete message or an RRCResumeComplete message) to the base station indicating that it has frequency measurement results measured in RRC idle mode or RRC inactive mode.

[0096] For example, if the UE has valid frequency measurement results that satisfy predetermined conditions, it performs frequency measurement (early measurement) in RRC idle mode or RRC inactive mode when transmitting message 5 (e.g., RRC Setup Complete or RRC Resume Complete) and transmits the message including an indicator that there are frequency measurement results to report. For the indicator included in message 5, a new indicator may be defined to indicate that there are early frequency measurement results, or an indicator already defined in the RRC message (RRC Setup Complete or RRC Resume Complete) that notifies the UE that there is useful information may be reused (6-50). When indicating that there are frequency measurement results measured in RRC idle mode or RRC inactive mode in message 5, an indicator for measurement results for LTE frequencies and an indicator for measurement results for NR frequencies may be defined and indicated, respectively.

[0097] If the base station determines from the indicator in message 5 that the UE has performed early frequency measurement in RRC idle mode or RRC inactive mode and has measurement results to report, it transmits a measurement result report message to the UE to receive an early report of the frequency measurement results (6-55). For example, the base station defines a new UEInformationRequest in the DL-DCCH message and uses it to request frequency measurement result information from the UE. Upon receiving the message, the UE reports early frequency measurement results to the base station (6-65). For example, upon receiving the message, the UE defines a new UEInformationResponse message in the UL-DCCH message and uses it to report the frequency measurement results. The frequency measurement results include serving cell / frequency measurement results (e.g., NR-SS RSRP / RSRQ), neighboring cell / frequency measurement results of the serving cell / frequency, neighboring cell / frequency measurement results that the UE can measure, and measurement-instructed cell / frequency measurement results. Alternatively, the base station can define an indicator in the RRCReconfiguration message and use it to request frequency measurement result information from the UE. Upon receiving the message, the terminal reports the early frequency measurement result to the base station (6-65). For example, upon receiving the message, the terminal reports the frequency measurement result using an RRCReconfigurationComplete message, or alternatively, the terminal can define a new field for reporting the frequency measurement result in the UL-DCCH message and use this field to report the frequency measurement result.

[0098] Figure 7 is a diagram showing a second embodiment in which a terminal in a next-generation mobile communication system according to one embodiment of the present invention performs early frequency measurement in RRC idle mode or RRC inactive mode and reports a fast frequency measurement result (fast measurement report).

[0099] In the second embodiment of the present invention, the content of the first embodiment is applied, and the base station configures, in an RRCRelease message, first frequency measurement configuration information to be applied when the terminal performs frequency measurement in RRC idle mode or RRC inactive mode. The terminal performs frequency measurement in RRC idle mode or RRC inactive mode based on the first frequency configuration information or second frequency configuration information in the system information. When the terminal establishes a connection with a network for data transmission / reception, the base station transmits an RRC message (e.g., an RRCResume message) to the terminal including an indicator requesting frequency measurement results. When the terminal receives the indicator requesting frequency measurement results and has valid frequency measurement results, the terminal constructs valid frequency measurement results, includes the valid frequency measurement results in an RRC message (e.g., an RRCResumeComplete message), and transmits the result to the base station to report the frequency measurement results.

[0100] In Figure 7, when a UE in RRC connected mode receives first frequency measurement configuration information together with an instruction to release the RRC connection from the base station and transition to RRC idle mode or RRC inactive mode, the UE performs frequency measurement for a set period or time in RRC idle mode or RRC inactive mode. Also, when second frequency measurement configuration information for frequency measurement of a UE in RRC idle mode or RRC inactive mode is broadcast in a capped-on cell while performing a cell reselection procedure, the UE can receive the information and perform frequency measurement.

[0101] When the terminal attempts to establish a new connection with the network in RRC idle mode or RRC inactive mode, if the cell to which the terminal is attempting to establish the current connection supports early reporting of frequency measurement results (e.g., if an indicator indicates whether support is provided in the system information), the terminal performs a random access procedure, transmits message 3 (e.g., RRCResumeRequest), and receives message 4 (e.g., RRCResume message, 7-40) including an indicator requesting the base station to report frequency measurement results. If the terminal receives a frequency measurement result report indicator in an RRC message (e.g., RRCResume message), the terminal reports the frequency measurement results by constructing the frequency measurement results, including them in an RRC message (e.g., RRCResumeComplete message) 7-50, and transmitting the result to the base station. When the base station receives the frequency measurement result, it transmits an RRC message (e.g., an RRC Reconfiguration message) or MAC control information (MAC Control Element, MAC CE) to the terminal together with frequency aggregation technology setting information or dual connectivity technology setting information, thereby promptly reactivating, changing, or newly configuring the frequency aggregation technology or dual connectivity technology to the terminal (7-40). Therefore, it is possible to report the frequency measurement result more quickly than in the first embodiment.

[0102] Next, in the first or second embodiment of the present invention, specific configuration information is proposed for the first frequency configuration information that the base station sets in the RRCRelease message and the second frequency configuration information that the base station broadcasts in the system information so that the terminal can save battery and efficiently perform the frequency measurement procedure in the RRC idle mode or the RRC inactive mode.

[0103] The first frequency configuration information set in the RRC message proposed in the present invention (for example, RRC connected mode frequency measurement is set in an RRCReconfiguration message, and RRC idle mode or RRC inactive mode frequency measurement is set in an RRCRelease message) includes one or more of the following multiple configuration information:

[0104] - List of frequencies to be measured for the first LTE frequency

[0105] - A list of SSB (Synchronization Signal Block) frequencies to be measured for the first NR frequency

[0106] - Cell list (list including cell identifiers) that must be measured and reported by frequency: When measuring the frequency, the terminal measures only signals corresponding to cell identifiers included in the set cell list among the cells operated by the frequency, and stores and reports to the network if the specified conditions are met.

[0107] - Threshold information that serves as the standard for measuring and reporting by frequency: When the terminal measures a signal having a cell identifier included in the cell list when measuring the frequency with a signal strength stronger than the threshold, it determines that the measurement result is valid, stores it, and reports the frequency measurement result when subsequently connecting to the network.

[0108] - First setting information for frequency-specific SSB measurement: Auxiliary information that helps the terminal easily measure SSB frequency-specific SSB is set, and includes one or more pieces of setting information such as:

[0109] ■ smtc (SSB block Measurement Time Configuration) setting information: Information including the period, offset, or cycle during which SSB is transmitted as time setting information for SSB measurement of frequency ■ ssbSubcarrierSpacing setting information: Information including frequency spacing for SSB measurements ■ssb-ToMeasure setting information: Measured SSB identifier information in SSB ■nrofSS-BlocksToAverage: Parameter information for cell signal strength guidance absThreshSS-BlocksConsolidation: Parameter information for cell signal strength guidance

[0110] - Reporting method for first frequency-specific measurement report (e.g., RSRP or RSRQ or beam measurement result or beam identifier or multiple beam measurement results or multiple beam identifiers): Indicate the type of measurement result to be reported by the UE per frequency or cell. For example, instruct to report RSRP or RSRQ, or instruct to also report beam measurement results, or instruct to report a beam identifier with valid signal strength, or instruct to report multiple beam measurement results or a beam identifier with multiple valid signal strengths, or instruct to report the measurement result or beam identifier of the beam with the best signal strength in other ways.

[0111] -First deriveSSB-IndexFromCell configuration information: When performing intra-frequency measurement, if the indicator is set to True, it means that when deriving the SSB identifier of the SSB block in the configured SMTC configuration information of another cell when measuring another cell of the frequency, the timing of the current PCell or serving cell is used as the reference timing. Therefore, the UE can immediately know the SSB identifier of the frequency to be measured without reading the PBCH (Physical Broadcast Channel), thereby saving the UE's power consumed for frequency measurement and enabling quick measurement. If the indicator is set to False, the UE must synchronize with the cell of the frequency to be measured and read the PBCH to derive each SSB identifier for the SSB block. Also, when performing inter-frequency measurement, if inter-frequency measurement must be performed for the frequency to be measured, if the indicator is set to True, when synchronizing with any cell of the frequency to be measured, the synchronized cell can be used as reference timing when performing SSB measurement for other cells of that frequency, meaning that the SSB identifier is derived based on the timing reference. If the indicator is False, the terminal synchronizes with each cell of the frequency and performs SSB measurement.

[0112] First region configuration information: Configuration information for a region in which a terminal performs frequency measurement in RRC idle mode or RRC inactive mode, including, for example, a cell list (a list including cell identifiers) for each frequency.

[0113] First timer (e.g., valid timer) value or period: A timer indicating a period during which the terminal performs frequency measurement in RRC idle mode or RRC inactive mode. For example, when the first timer value or period is set in the RRCRelease message, the terminal starts the first timer and performs frequency measurement in RRC idle mode or RRC inactive mode based on the frequency configuration information set in the first frequency configuration information or the second frequency configuration information. When the terminal receives an RRCSetup message or an RRCResume message from the base station when establishing a connection with the network, it is considered to transition to the RRC connected mode, and the first timer is stopped. Also, when the terminal leaves a first area (e.g., a validity area), the first timer is stopped. When the first timer is stopped, the terminal may release the frequency configuration information and stop frequency measurement, or discard the frequency measurement results.

[0114] Second timer value or period: To confirm the validity of the frequency measurement result, the base station sets a second timer value in the first frequency configuration information. The second timer is used to indicate the period for determining the validity of the frequency measurement result. The stored frequency measurement result value is determined to be valid only while the second timer is running. When the second timer expires, the stored frequency measurement result value is discarded and not reported to the base station. The second timer is driven per terminal and starts when the first timer indicating the frequency measurement period expires or frequency measurement is stopped. When the second timer expires, the stored frequency measurement result is determined to be no longer valid and discarded. When the second timer is running, the second timer is stopped when the terminal receives a frequency measurement result report request from the base station or when the terminal attempts to transmit the frequency measurement result to the base station in an RRC message. The second timer is driven per frequency or cell and starts a new timer when the first timer indicating the frequency measurement period expires or frequency measurement is stopped. Alternatively, a second timer corresponding to each cell or frequency is started or restarted each time frequency measurement is performed for each cell or frequency and new frequency measurement results are stored for each cell or frequency. When the second timer expires, the stored frequency measurement results for the cell or frequency for which the second timer is activated are determined to be no longer valid and discarded. When the second timer is activated, the terminal receives a frequency measurement result report request from the base station or the terminal attempts to transmit the frequency measurement results from the base station in an RRC message, the second timer is stopped.

[0115] Reference frequency or cell list for SSB measurement by frequency: This is the setting information for the frequency or cell synchronized with the current base station or frequency that serves as the timing reference when performing frequency measurement on the frequency or cell set in the frequency list to be measured for LTE frequencies or the SSB (Synchronization Signal Block) frequency list to be measured for NR frequencies. When performing frequency measurement setting, after the terminal synchronizes with one of the frequencies or cells set in the reference frequency or cell list, the terminal performs frequency measurement on other frequencies.

[0116] The second frequency configuration information set in the system information proposed in the present invention includes one or more pieces of configuration information as follows: The second frequency configuration information is different from the first frequency configuration information in that it does not include the first timer configuration information, the first region configuration information, or the second timer configuration information.

[0117] -Frequency list to be used for second LTE frequency measurement (frequency list for RRC idle mode or RRC inactive mode frequency measurement of the terminal or measurement setting information for neighboring cells or other frequencies useful for camp-on determination when the terminal selects or reselects a cell)

[0118] -SSB (Synchronization Signal Block) frequency list to be used for second NR frequency measurement (frequency list for RRC idle mode or RRC inactive mode frequency measurement of the terminal or measurement setting information for neighboring cells or other frequencies useful for camp-on determination when the terminal selects or reselects a cell)

[0119] - Cell list (list including cell identifiers) that must be measured and reported by frequency: The terminal measures only signals corresponding to cell identifiers included in the set cell list among cells operating at the frequency when measuring the frequency, and stores and reports to the network if the specified conditions are met.

[0120] - Threshold information that serves as the standard for measuring and reporting by frequency: When the terminal measures a signal having a cell identifier included in the cell list when measuring the frequency, the terminal determines that the signal strength is stronger than the threshold and stores it as a valid measurement result. Then, the terminal reports the frequency measurement result when connecting to the network.

[0121] - Second setting information for SSB measurement by frequency: Auxiliary information that helps facilitate SSB measurement by frequency is set in the terminal, and includes one or more pieces of setting information such as:

[0122] ■ Second smtc (SSB block Measurement Time Configuration) setting information: Information including the period, offset, or cycle during which SSB is transmitted as time setting information for SSB measurement of the frequency ■ ssbSubcarrierSpacing setting information: Information including frequency spacing for SSB measurements ■ ssb-ToMeasure setting information: Measured SSB identifier information among SSB ■nrofSS-BlocksToAverage: Parameter information for cell signal strength guidance absThreshSS-BlocksConsolidation: Parameter information for cell signal strength guidance

[0123] - Reporting method for second frequency-specific measurement report (e.g., RSRP or RSRQ or beam measurement result or beam identifier or multiple beam measurement results or multiple beam identifiers): Instructs the type of measurement result to be reported by the UE by frequency or cell. For example, it may instruct to report RSRP or RSRQ, or to also report beam measurement results, or to report a beam identifier with valid signal strength, or to report multiple beam measurement results or a beam identifier with valid signal strength, or it may instruct to report the measurement result or beam identifier of the beam with the best signal strength in other ways.

[0124] - Second deriveSSB-IndexFromCell configuration information: When performing intra-frequency measurement, if the indicator is set to True, it means that the timing of the current PCell or serving cell is used as the reference timing when deriving the SSB identifier of the SSB block in the configured SMTC configuration information of other cells when measuring other cells of the frequency. Therefore, the UE can immediately know the SSB identifier of the frequency to be measured without reading the PBCH (Physical Broadcast Channel), thereby saving the UE's power consumed for frequency measurement and performing measurements quickly. If the indicator is set to False, the UE must synchronize with the cell of the frequency to be measured and read the PBCH to derive each SSB identifier for the SSB block. Also, when performing inter-frequency measurement, if inter-frequency measurement must be performed for the frequency to be measured, if the indicator is set to True, it indicates that if any cell of the frequency to be measured is synchronized, the synchronized cell can be used as reference timing when performing SSB measurement for other cells of that frequency, and the SSB identifier is derived based on the timing reference. If the indicator is False, the terminal synchronizes with each cell of the frequency and performs SSB measurement.

[0125] FIG. 8 is a diagram illustrating a specific signal configuration when a terminal performs RRC idle mode or RRC inactive mode frequency measurement on an LTE frequency according to an embodiment of the present invention.

[0126] The LTE frequency refers to the frequency at which an LTE base station or an NR base station operates a cell in the LTE system, and the configuration of the signal transmitted by the base station at the LTE frequency is as shown in Figure 8.

[0127] In Figure 8, when a base station transmits a signal at a system bandwidth (BW) 8-05 such as 8-05 for a first LTE frequency 8-10, a terminal must read the signal according to the entire system bandwidth for the LTE frequency. LTE frequency signals use a subcarrier spacing determined for all or most frequencies, excluding broadcast services or specific services such as MBMS, and SSBs having the same period, interval, or offset are transmitted at predetermined frequency positions (e.g., the middle 6 PRBs (Physical Resource Blocks) of the system bandwidth), and CRS (Channel Reference Signal) 8-20 is uniformly transmitted as 8-20 according to a predetermined rule.

[0128] When a terminal performing frequency measurement in RRC idle mode or RRC inactive mode proposed in the present invention performs measurement on an LTE frequency, it first reads signals in a system bandwidth defined for the LTE frequency and finds SSB signals at a defined position. Furthermore, since SSB signals use a subcarrier spacing defined for all or most of the frequencies and have the same period, duration, or offset, the terminal quickly synchronizes and finds the SSB signals. The terminal performs frequency measurement by reading MIB (Master Information Block) signals based on the SSB signals and measuring CRS signals that are uniformly transmitted. Because CRS is uniformly and constantly transmitted on LTE frequencies, this method has the advantage that the terminal can quickly find CRS transmission resources and perform fast frequency measurement. Alternatively, frequency measurement can be performed by measuring SSB signals on LTE frequencies using another method. Alternatively, an indicator set in an RRCRelease message or system information can be used to indicate whether to measure SSB signals or CRS for LTE frequencies, and the terminal can perform frequency measurement according to the indicator. Then, when a predetermined condition set in the first frequency information or the second frequency information is satisfied, the frequency measurement result is reported based on the set method.

[0129] 9 and 10 are diagrams illustrating specific signal configurations when a terminal according to an embodiment of the present invention performs RRC idle mode or RRC inactive mode frequency measurement on an NR frequency.

[0130] The NR frequency refers to the frequency at which an NR base station or an LTE base station operates a cell in the NR system, and the configuration of the signal transmitted by the base station at the NR frequency is as shown in Figures 9 and 10.

[0131] In Figure 9, the base station transmits a signal at a system bandwidth (BW) 9-05, such as 9-05, for the first NR frequency 9-01, and the terminal does not read the signal according to the entire system bandwidth for the NR frequency, but reads the signal according to a partial bandwidth (BWP) (9-10, 9-20) such as 9-10 or 9-20. This is because the system bandwidth is very wide for each frequency in the NR system, and if the terminal reads the entire system bandwidth, a lot of battery consumption occurs, and the base station operates multiple partial bandwidths for each frequency. Therefore, the terminal reads the signal for a specific portion of the bandwidth (e.g., the initial portion of the bandwidth, initial BWP) for each frequency, finds the SSB, synchronizes, and measures the signal for the SSB. The base station uses different subcarrier spacings for each partial bandwidth or frequency when operating the frequency, and transmits SSBs with different periods, intervals, or offsets at a predetermined frequency position (e.g., the middle 12 PRBs (Physical Resource Blocks) of the partial bandwidth). In addition, unlike LTE frequencies, CRS (Channel Reference Signal) 8-20 does not need to be transmitted. This is because the base station operates multiple partial bandwidths for the NR frequency, which has a very wide bandwidth, and transmitting a CRS would result in a huge overhead for the signal transmitted by the base station. An SSB signal may or may not be transmitted for each partial bandwidth among multiple partial bandwidths, but an SSB signal is always transmitted for a specific partial bandwidth (e.g., initial partial bandwidth, initial BWP) so that a terminal in RRC idle mode or RRC inactive mode can synchronize a signal to a specific partial bandwidth, acquire system information, and cap on.

[0132] As described above, in NR frequencies, different subcarrier spacings are used for each frequency, and SSB signals having different periods, periods, or offsets are transmitted, so the terminal searches for the SSB signal for a long time to find the SSB signal for each frequency and find the different periods, periods, or offset values. As such, the terminal must calculate the period, period, or offset value of the SSB signal through complex calculations, which causes significant battery consumption in the terminal.

[0133] Therefore, the present invention proposes that a UE can easily perform frequency measurement by configuring or broadcasting smtc configuration information for frequencies that need to be measured in first frequency configuration information configured in an RRC message or second frequency configuration information broadcast in system information as shown in Figure 10. The smtc configuration information includes an offset, period, or duration for frequencies that need to be measured, and the reference timing for the parameters (offset, period, or duration) included in the smtc configuration information (10-21, 10-22, 10-23) is based on the timing of the PCell or serving cell (10-01, 10-05). For example, when frequency measurement is configured by the UE in RRC connected mode, the UE performs measurement on frequencies that need to be measured by applying smtc information (10-21, 10-22, 10-23) based on the timing of the current PCell (e.g., PCell System Frame Number (SFN) 0th (10-01, 10-05)). Also, when the UE is configured to perform frequency measurement in RRC idle mode or RRC inactive mode, the UE performs measurement on frequencies that need to be measured by applying smtc information (10-21, 10-22, 10-23) based on the timing of the currently camped-on serving cell (e.g., serving cell System Frame Number (SFN) 0th (10-01, 10-05)).

[0134] The specific procedure proposed in the present invention for a terminal to perform frequency measurement based on smtc information in RRC connected mode is as follows.

[0135] When the terminal receives first frequency configuration information in an RRC message from the base station in the RRC connected mode, the terminal prepares frequency measurement for the frequency or cell set in the first frequency configuration information.

[0136] When attempting to measure a specific frequency in the configured frequency list, if smtc configuration information is included for the frequency, the smtc configuration information is applied based on the timing of the currently connected PCell 10-01. That is, the UE measures the SSB signal in the interval where the SSB signal is transmitted by applying the duration value of the smtc information, reflecting the offset of the smtc information based on the SFN (System Frame Number) 0 (10-05) of the current PCell, and then continues to measure the SSB signal at the point where the next SSB signal is transmitted by applying the periodicity value of the smtc information. Since smtc configuration information is configured for the frequency, the UE immediately measures the frequency of the current PCell based on the smtc information for the frequency based on the reference timing. This eliminates the need to synchronize with the frequency, search for the SSB signal from scratch, and derive the period, offset, and interval parameter values, thereby reducing UE battery consumption and enabling faster frequency measurement.

[0137] The specific procedure proposed in the present invention for a terminal to perform frequency measurement based on smtc information in RRC idle mode or RRC inactive mode is as follows.

[0138] When the terminal receives first frequency configuration information in an RRC message in RRC idle mode or RRC inactive mode, or receives second frequency configuration information from the system information of the serving cell on which it is camped through a cell selection or reselection procedure, it prepares frequency measurements for the frequencies or cells set in the first frequency configuration information or second frequency configuration information.

[0139] When attempting to measure a specific frequency in the configured frequency list, if SMTC configuration information is included for the frequency, the UE applies the SMTC configuration information based on the timing of the serving cell 10-01 on which it camped through a cell selection or reselection procedure in RRC idle mode or RRC inactive mode. That is, the UE measures the SSB signal in the interval in which the SSB signal is transmitted by applying the duration value of the SMTC information, reflecting the offset (10-21) of the SMTC information based on the SFN (System Frame Number) 0 (10-05) of the current serving cell, and continues to measure the SSB signal at the time the next SSB signal is transmitted by applying the periodicity value of the SMTC information. Since SMTC configuration information is configured for the frequency, the UE immediately performs frequency measurement of the current serving cell based on the SMTC information for the frequency based on the reference timing. This eliminates the need to synchronize with the frequency, search for the SSB signal from scratch, and derive the period, offset, and interval parameter values, thereby preventing battery drain on the device and enabling fast frequency measurement.

[0140] A terminal performing frequency measurement in RRC idle mode or RRC inactive mode proposed in the present invention is characterized in that, when performing measurement on an NR frequency, it first finds an SSB signal for a specific partial bandwidth (e.g., initial partial bandwidth, initial BWP) of the NR frequency. Furthermore, since SSB signals use different subcarrier spacings and have different periods, intervals, or offsets for different frequencies, the terminal subsequently searches for the SSB signal and calculates and derives period, interval, or offset parameter values. Unlike measuring CRS signals for LTE frequencies, the terminal performs frequency measurement on the SSB signal based on the parameter values ​​derive for the NR frequency. Then, if a predetermined condition set in the first frequency information or the second frequency information is satisfied, the terminal reports the frequency measurement result based on a set method.

[0141] The proposed method of performing frequency measurements for LTE frequencies or NR frequencies is extended and applied to the method of a terminal performing frequency measurements in RRC idle mode, RRC inactive mode, or RRC connected mode.

[0142] Furthermore, when a terminal attempts to perform frequency measurement, if the frequency to be measured is an LTE frequency, the terminal performs frequency measurement using the method proposed in Figure 8 of this specification, and if the frequency to be measured is an NR frequency, the terminal performs frequency measurement using the method proposed in Figure 9 or Figure 10 of this specification.

[0143] FIG. 11 is a diagram illustrating a method for a terminal to perform RRC idle mode or RRC inactive mode frequency measurement in a network synchronized between different frequencies or cells according to an embodiment of the present invention.

[0144] In Figure 11, the terminal is transmitting and receiving data in the current cell 1 (11-01) in the RRC connected mode, and therefore receives an RRCRelease message from the base station of cell 1, transitions to the RRC idle mode or the RRC inactive mode, and moves while performing a cell selection or reselection procedure. The RRCRelease message includes first frequency configuration information. Furthermore, the terminal in the RRC idle mode or the RRC inactive mode performs a cell selection or reselection procedure while moving, and caps on a suitable cell to acquire system information. From the system information, the terminal receives second frequency measurement configuration information.

[0145] When the UE receives an RRCRelease message and first frequency configuration information is included, the UE drives a timer by reflecting first timer value information in the first frequency configuration information and starts frequency measurement (early measurement) in RRC idle mode or RRC inactive mode. Also, when first region configuration information is included in the first frequency configuration information, the UE checks the identifier of a cell to camp on when performing a cell selection or reselection procedure and determines whether to perform frequency measurement (early measurement) in RRC idle mode or RRC inactive mode.

[0146] When the UE is in an area where cell 1 (11-01) supports services, it performs RRC idle mode or RRC inactive mode measurements based on the first frequency configuration information received from the RRCRelease message or the second frequency configuration information broadcast in the system information of cell 1. That is, when attempting to measure frequency 1 (frequency 1) 11-10 in the configured frequency list, if the first frequency configuration information received from cell 1 for the frequency includes first smtc configuration information, or if the second frequency configuration information received from the system information of cell 1 includes second smtc configuration information, the UE applies the smtc configuration information based on the timing of the serving cell (cell 1, 11-01) camped on through the cell selection or reselection procedure in RRC idle mode or RRC inactive mode. That is, the UE measures the SSB signal during the interval in which the SSB signal is transmitted by applying the duration value of the SMTC information, reflecting the offset of the SMTC information based on the SFN (System Frame Number) 0 (11-01) of the current serving cell, and then continues to measure the SSB signal at the time when the next SSB signal is transmitted by applying the periodicity value of the SMTC information. Since the SMTC configuration information is set for the frequency, the UE immediately performs frequency measurement of the current serving cell based on the SMTC information for the frequency based on the reference timing. Since there is no need to synchronize with the frequency and search for the SSB signal from scratch to derive the period, offset, and period parameter values, it is possible to prevent UE battery consumption and perform fast frequency measurement. If the SMTC configuration information is not included for the frequency, the UE does not perform frequency measurement in RRC idle mode or RRC inactive mode for the frequency to reduce battery consumption. Alternatively, even if there is no SMTC configuration information, the terminal can synchronize with the frequency in the implementation, search for the SSB signal from the beginning, derive period, offset, and interval parameter values, and perform RRC idle mode or RRC inactive mode frequency measurement.

[0147] When the UE moves from cell 1 (11-01) to an area where cell 2 (11-02) supports services and camps on cell 2 (11-02), it performs RRC idle mode or RRC inactive mode measurements based on the first frequency configuration information received from the RRCRelease message of the previous cell 1 (11-01) or the second frequency configuration information broadcast in the system information of cell 2. That is, when attempting to measure frequency 2 (frequency 2) 11-20 in the configured frequency list, if the first frequency configuration information received from cell 1 for the frequency includes first SMTC configuration information, or if the second frequency configuration information received from the system information of cell 2 includes second SMTC configuration information, the UE applies the SMTC configuration information based on the timing of the serving cell (cell 2, 11-02) on which it camped through the cell selection or reselection procedure in RRC idle mode or RRC inactive mode. That is, the terminal measures the SSB signal during the interval in which the SSB signal is transmitted by applying the duration value of the SMTC information, reflecting the offset of the SMTC information based on the SFN (System Frame Number) 0 (11-01) of the current serving cell, and continues to measure the SSB signal at the time the next SSB signal is transmitted by applying the periodicity value of the SMTC information. Since the SMTC configuration information is set for the frequency, the terminal immediately performs frequency measurement of the current serving cell based on the SMTC information for the frequency based on the reference timing, and does not need to synchronize with the frequency and search for the SSB signal from scratch to derive the period, offset, and interval parameter values, thereby preventing battery consumption in the terminal and enabling fast frequency measurement. If the SMTC configuration information is not included for the frequency, the terminal does not perform frequency measurement in RRC idle mode or RRC inactive mode for the frequency to reduce battery consumption. Alternatively, even if there is no SMTC configuration information, the terminal can synchronize with the frequency in the implementation, search for the SSB signal from the beginning, derive period, offset, and interval parameter values, and perform RRC idle mode or RRC inactive mode frequency measurement.

[0148] Figure 12 is a diagram illustrating a problem that occurs when a terminal performs frequency measurement in RRC idle mode or RRC inactive mode in a network that is not synchronized between different frequencies or cells according to an embodiment of the present invention.

[0149] In Figure 12, the terminal is transmitting and receiving data in the current cell 1 (12-01) in the RRC connected mode, and therefore receives an RRCRelease message from the base station of cell 1, transitions to the RRC idle mode or the RRC inactive mode, and moves while performing a cell selection or reselection procedure. The RRCRelease message includes first frequency configuration information. Also, while moving in the RRC idle mode or the RRC inactive mode, the terminal performs a cell selection or reselection procedure, capping on a suitable cell and acquiring system information. From the system information, the terminal receives second frequency measurement configuration information.

[0150] When the UE receives an RRCRelease message and first frequency configuration information is included, the UE drives a timer by reflecting first timer value information in the first frequency configuration information and starts frequency measurement (early measurement) in RRC idle mode or RRC inactive mode. Also, when first region configuration information is included in the first frequency configuration information, the UE checks the identifier of a cell to camp on when performing a cell selection or reselection procedure and determines whether to perform frequency measurement (early measurement) in RRC idle mode or RRC inactive mode.

[0151] When cell 1 (12-01) is in an area supporting the service, the terminal performs RRC idle mode or RRC inactive mode measurements based on the first frequency configuration information received from the RRCRelease message or the second frequency configuration information broadcast in the system information of cell 1. That is, when attempting to measure frequency 1 (frequency 1, 12-10) in the configured frequency list, if the first frequency configuration information received from cell 1 for the frequency includes first SMTC configuration information, or if the second frequency configuration information received from the system information of cell 1 includes second SMTC configuration information, the terminal applies the SMTC configuration information based on the timing of the serving cell (cell 1, 12-01) camped on through the cell selection or reselection procedure in RRC idle mode or RRC inactive mode. That is, the terminal measures the SSB signal during the interval in which the SSB signal is transmitted by applying the duration value of the SMTC information, reflecting the offset of the SMTC information based on the SFN (System Frame Number) 0 (12-01) of the current serving cell, and continues to measure the SSB signal at the time the next SSB signal is transmitted by applying the periodicity value of the SMTC information. Since the SMTC configuration information is set for the frequency, the terminal immediately performs frequency measurement of the current serving cell based on the SMTC information for the frequency based on the reference timing, and does not need to synchronize with the frequency and search for the SSB signal from scratch to derive the period, offset, and interval parameter values, thereby preventing battery consumption in the terminal and enabling fast frequency measurement. If the SMTC configuration information is not included for the frequency, the terminal does not perform frequency measurement in RRC idle mode or RRC inactive mode for the frequency to reduce battery consumption. Alternatively, even if there is no SMTC configuration information, the terminal can synchronize with the frequency in the implementation, search for the SSB signal from the beginning, derive period, offset, and interval parameter values, and perform RRC idle mode or RRC inactive mode frequency measurement.

[0152] When the UE moves from cell 1 (12-01) to an area where cell 2 (12-02) supports services and camps on cell 2 (12-02), it performs RRC idle mode or RRC inactive mode measurements based on the first frequency configuration information received from the RRCRelease message of the previous cell 1 (12-01) or the second frequency configuration information broadcast in the system information of cell 2. That is, when attempting to measure frequency 2 (frequency 2) 12-20 in the configured frequency list, if the first frequency configuration information received from cell 1 for the frequency includes first SMTC configuration information, or if the second frequency configuration information received from the system information of cell 2 includes second SMTC configuration information, the UE applies the SMTC configuration information based on the timing of the serving cell (cell 2, 12-02) on which it camped through the cell selection or reselection procedure in RRC idle mode or RRC inactive mode. That is, in the interval in which the SSB signal is transmitted by applying the duration value of the smtc information, reflecting the offset of the smtc information based on the SFN (System Frame Number) 0 (12-01) of the current serving cell, the terminal measures the SSB signal, and continues to measure the SSB signal at the time when the next SSB signal is transmitted by applying the periodicity value of the smtc information.

[0153] However, in Figure 12, since time synchronization between cell 1 (12-01) and cell 2 (12-02) does not apply, when the UE applies the first smtc information for frequency 2 (12-20) included in the first frequency configuration information received from the RRCRelease message of cell 1 to measure frequency 2 (12-20) in cell 2, a frequency measurement failure problem due to asynchronization may occur. This is because the first smtc information for frequency 2 (12-20) included in the first frequency configuration information received from the RRCRelease message of cell 1 is information set based on the reference timing of cell 1. However, when the UE applies the first smtc information based on the reference timing of cell 2 in the cell 2 area, the frequency measurement period is shifted by the gap between the timing of cell 1 and the timing of cell 2. Therefore, the UE may not be able to properly perform frequency measurement on frequency 2 in RRC idle mode or RRC inactive mode.

[0154] Next, we will specifically propose an efficient RRC idle mode or RRC inactive mode frequency measurement method that solves the frequency measurement failure problem due to asynchrony that occurs in FIG. 12 and minimizes battery consumption of the terminal.

[0155] FIG. 13 illustrates a first example of an efficient RRC idle mode or RRC inactive mode frequency measurement method according to an embodiment of the present invention.

[0156] In FIG. 13, the base station or cell configures the terminal with configuration information for RRC idle mode or RRC inactive mode frequency measurement using first frequency measurement configuration information 13-10 in the RRCRelease message or second frequency measurement configuration information 13-20 in the system information.

[0157] When the UE receives an RRCRelease message and first frequency configuration information is included, the UE drives a timer by reflecting first timer value information in the first frequency configuration information and starts RRC idle mode or RRC inactive mode frequency measurement (early measurement). If the first frequency configuration information includes first region configuration information, the UE checks the identifier of the cell on which the UE will camp when performing a cell selection or reselection procedure to determine whether to perform RRC idle mode or RRC inactive mode frequency measurement (early measurement). If the first frequency configuration information does not include first frequency list information on which measurements must be performed, the UE performs RRC idle mode or RRC inactive mode frequency measurement based on the second frequency configuration information (e.g., second frequency list information) when second frequency configuration information is broadcast in the system information of the cell on which the UE is camped through the cell selection or reselection procedure, stores valid measurement results, and subsequently reports the measurement results to the network in the manner shown in FIG. 6 or 7 when establishing an RRC connection.

[0158] In a first specific embodiment of the efficient frequency measurement method in RRC idle mode or RRC inactive mode proposed in Fig. 13, a terminal receives first frequency configuration information through an RRCRelease message, transitions to RRC idle mode or RRC inactive mode, and performs frequency measurement. The terminal also receives second frequency configuration information from system information of the camped-on cell through a cell selection or reselection procedure.

[0159] In a first embodiment of the present invention, a terminal receives first frequency configuration information or second frequency configuration information, and when performing frequency measurement in RRC idle mode or RRC inactive mode, the terminal prioritizes the first frequency configuration information and performs frequency measurement based only on the first frequency configuration information. Alternatively, in another method, frequency measurement can be performed taking into account the second frequency configuration information for configuration information not included in the first frequency configuration information.

[0160] For example, the terminal receives the first frequency configuration information 13-10 by receiving an RRCRelease message from cell 1, and receives the second frequency configuration information 13-20 in the system information from cell 1 or a new cell 2 through a cell selection or reselection procedure after transitioning to RRC idle mode or RRC inactive mode.

[0161] The first frequency list of the first frequency setting information 13-10 includes frequency 1 (13-01), frequency 2 (13-02), frequency 3 (13-03), frequency 4 (13-04), frequency 5 (13-05), and frequency 6 (13-06) as targets for frequency measurement, and threshold information that serves as a standard for measuring and reporting only for frequency 1 (13-01), frequency 2 (13-02), frequency 3 (13-03), and frequency 5 (13-05) among the set frequencies, or setting information for first frequency-specific SSB measurement, or a reporting method for first frequency-specific measurement reporting is set.

[0162] The second frequency list of the second frequency setting information 13-20 includes frequency 3 (13-03), frequency 4 (13-04), frequency 5 (13-05), frequency 6 (13-06), frequency 7 (13-07), and frequency 8 (13-08) as targets for frequency measurement, and threshold information that serves as a standard for measuring and reporting only for frequency 3 (13-03), frequency 4 (13-04), frequency 7 (13-07), and frequency 8 (13-08) among the set frequencies, or setting information for SSB measurement by second frequency, or a reporting method for measurement reporting by second frequency, is set.

[0163] When the terminal receives the first frequency configuration information 13-10 or the second frequency configuration information 13-20, it selects the frequency on which to perform measurement in order to perform RRC idle mode or RRC inactive mode frequency measurement, and applies one of the following methods to determine the frequency configuration to apply to each frequency.

[0164] - Method 1-1 13-51: The terminal performs frequency measurement by prioritizing the first frequency configuration information 13-10. Therefore, the terminal performs frequency measurement only on the frequencies set in the first frequency list (13-51, frequency 1 (13-01), frequency 2 (13-02), frequency 3 (13-03), frequency 4 (13-04), frequency 5 (13-05), frequency 6 (13-06)), and performs frequency measurement by reflecting frequency measurement configuration information for each frequency set in the first frequency configuration information (e.g., threshold information serving as a standard for measuring and reporting by frequency, or configuration information for SSB measurement by the first frequency, or a reporting method for measurement reporting by the first frequency), determines valid frequency measurement results, and composes and stores the results to be reported. Specifically, in method 1-1, the UE performs frequency measurement by reflecting configuration information (e.g., SMTC period, offset, and duration) for the first frequency-specific SSB measurement set for the frequency to be measured based on the reference timing of the serving cell on which it camped through a cell selection or reselection procedure. If there is no configuration information for the first frequency-specific SSB measurement for the frequency to be measured, the UE does not perform measurement on the frequency to reduce battery consumption. Alternatively, even if there is no configuration information for the first frequency-specific SSB measurement (e.g., SMTC period, offset, and duration), the UE can synchronize with the frequency in its implementation, search for an SSB signal from scratch, derive period, offset, and duration parameter values, and perform frequency measurement in RRC idle mode or RRC inactive mode. Alternatively, the UE can store the reference timing of the cell that received the RRCRelease message and perform measurement by applying configuration information for the first frequency-specific SSB measurement based on the stored timing. In the 1-1 method, the terminal performs frequency measurement based only on the first frequency setting information, so there is no need to read a lot of system information, which reduces battery consumption of the terminal.

[0165] - Method 1-2 13-52: The terminal performs frequency measurement by prioritizing the first frequency configuration information 13-10. Therefore, the terminal performs frequency measurement only on the frequencies (13-52), frequency 1 (13-01), frequency 2 (13-02), frequency 3 (13-03), frequency 4 (13-04), frequency 5 (13-05), and frequency 6 (13-06)) set in the first frequency list, and performs frequency measurement by reflecting frequency measurement configuration information for each frequency set in the first frequency configuration information (e.g., threshold information serving as a standard for measuring and reporting by frequency, or configuration information for SSB measurement by the first frequency, or a reporting method for measurement reporting by the first frequency), determines valid frequency measurement results, and composes and stores the results to be reported. Specifically, in method 1-2, the UE performs frequency measurement by reflecting configuration information (e.g., SMTC period, offset, and duration) for first frequency-specific SSB measurement set for the frequency to be measured based on the reference timing of the serving cell on which it is camped through a cell selection or reselection procedure. If there is no configuration information for first frequency-specific SSB measurement for the frequency to be measured but second frequency-specific SSB measurement configuration information for the frequency is broadcast in the second frequency configuration information received from the system information, the UE performs frequency measurement by reflecting configuration information (e.g., SMTC period, offset, and duration) for second frequency-specific SSB measurement set for the frequency to be measured based on the reference timing of the serving cell on which it is camped through a cell selection or reselection procedure (e.g., frequency 4 (13-04)). When measuring the frequency, if there is no configuration information for first frequency-specific SSB measurement for the frequency to be measured and the second frequency configuration information does not contain configuration information for second frequency-specific SSB measurement, the UE does not perform measurement on the frequency to reduce battery consumption.Alternatively, even if the UE does not have configuration information for SSB measurement for a first frequency (e.g., SMTC period, offset, and duration) or SSB measurement for a second frequency, the UE can synchronize with the frequency in the implementation, search for an SSB signal from scratch, derive period, offset, and duration parameter values, and perform frequency measurement in RRC idle mode or RRC inactive mode. Alternatively, the UE can store the reference timing of the cell that received the RRCRelease message and perform measurement by applying configuration information for SSB measurement for a first frequency or SSB measurement for a second frequency based on the stored timing.

[0166] A specific example 1-1 of another efficient method for measuring the frequency in RRC idle mode or RRC inactive mode according to the first embodiment is as follows.

[0167] In FIG. 13, the base station or cell configures the configuration information for RRC idle mode or RRC inactive mode frequency measurement in the terminal using first frequency measurement configuration information 13-10 in the RRCRelease message or second frequency measurement configuration information 13-20 in the system information.

[0168] When the UE receives an RRCRelease message and first frequency configuration information is included, the UE drives a timer by reflecting first timer value information in the first frequency configuration information and starts RRC idle mode or RRC inactive mode frequency measurement (early measurement). If the first frequency configuration information includes first region configuration information, the UE checks the identifier of the cell on which the UE will camp when performing a cell selection or reselection procedure and determines whether to perform RRC idle mode or RRC inactive mode frequency measurement (early measurement). If the first frequency configuration information does not include first frequency list information that is a target for measurement, the UE performs RRC idle mode or RRC inactive mode frequency measurement based on the second frequency configuration information (e.g., second frequency list information) when second frequency configuration information is broadcast in the system information of the cell on which the UE is camped through the cell selection or reselection procedure, stores valid measurement results, and subsequently reports the measurement results to the network in the manner shown in FIG. 6 or 7 when establishing an RRC connection.

[0169] In the first embodiment of the present invention, an efficient frequency measurement method in RRC idle mode or RRC inactive mode is proposed in which a terminal receives first frequency configuration information through an RRCRelease message, transitions to RRC idle mode or RRC inactive mode, performs frequency measurement, and receives second frequency configuration information from system information of a cell it camps on through a cell selection or reselection procedure.

[0170] In embodiment 1-1 of the present invention, when a terminal receives first frequency configuration information or second frequency configuration information and performs frequency measurement in RRC idle mode or RRC inactive mode, if both the first frequency configuration information and the second frequency configuration information are received, the terminal always applies the first frequency list information preferentially over the second frequency list information, but if both the first frequency configuration information for SSB measurement per frequency and the second frequency configuration information for SSB measurement per frequency are received, the terminal applies the second frequency list information preferentially. However, if the cell from which the terminal received the system information is a cell such as the cell from which the terminal received the RRCRelease message, if the terminal receives the first frequency-based SSB measurement configuration information for a specific frequency in the first frequency list in the RRCRelease message and receives the second frequency-based SSB measurement configuration information in the system information of the same cell, the terminal applies the first frequency-based SSB measurement configuration information for the frequencies in the first frequency list. This is because when different information is received in the RRCRelease message and system information in the same cell, the terminal must prioritize specific information provided directly by the base station as dedicated. Therefore, in the case of a terminal with low mobility that subsequently camps on the same cell, the configuration information for SSB measurement for the first frequency is more efficient for frequency measurement for carrier aggregation technology or dual connectivity technology.

[0171] Furthermore, when the RRCRelease message does not include information for configuring SSB measurements for the first frequency and only includes the first frequency list, if information for SSB measurements for the second frequency for each frequency included in the first frequency list is broadcast in the system information, frequency measurements are performed by applying the information for SSB measurements for the second frequency for the frequencies in the first frequency list.

[0172] For example, the terminal receives the first frequency configuration information 13-10 by receiving an RRCRelease message from cell 1, and receives the second frequency configuration information 13-20 in the system information from cell 1 or a new cell 2 through a cell selection or reselection procedure after transitioning to RRC idle mode or RRC inactive mode.

[0173] The first frequency list of the first frequency setting information 13-10 includes frequency 1 (13-01), frequency 2 (13-02), frequency 3 (13-03), frequency 4 (13-04), frequency 5 (13-05), and frequency 6 (13-06) as targets for frequency measurement, and threshold information that serves as a standard for measuring and reporting only for frequency 1 (13-01), frequency 2 (13-02), frequency 3 (13-03), and frequency 5 (13-05) among the set frequencies, or setting information for first frequency-specific SSB measurement, or a reporting method for first frequency-specific measurement reporting is set.

[0174] The second frequency list of the second frequency setting information 13-20 includes frequency 3 (13-03), frequency 4 (13-04), frequency 5 (13-05), frequency 6 (13-06), frequency 7 (13-07), and frequency 8 (13-08) as targets for frequency measurement, and threshold information that serves as a standard for measuring and reporting only for frequency 3 (13-03), frequency 4 (13-04), frequency 7 (13-07), and frequency 8 (13-08) among the set frequencies, or setting information for SSB measurement by second frequency, or a reporting method for measurement reporting by second frequency, is set.

[0175] When the terminal receives the first frequency configuration information 13-10 or the second frequency configuration information 13-20, it selects the frequency on which to perform measurement in order to perform RRC idle mode or RRC inactive mode frequency measurement, and applies one of the following methods to determine the frequency configuration to apply to each frequency.

[0176] -Method 1-1-1:

[0177] ■1> When the terminal moves within cell 1 where RRCRelease was received and then caps on to the same cell 1 (13-52)

[0178] ◆2> The terminal performs frequency measurement by prioritizing the first frequency configuration information 13-10. Accordingly, the terminal performs frequency measurements on frequency 1 (13-01), frequency 2 (13-02), frequency 3 (13-03), frequency 4 (13-04), frequency 5 (13-05), and frequency 6 (13-06) for the frequencies (13-51) set in the first frequency list, and performs frequency measurement by reflecting frequency measurement configuration information for each frequency set in the first frequency configuration information (e.g., threshold information serving as a standard for measuring and reporting by frequency, or configuration information for first frequency-specific SSB measurement, or a reporting method for first frequency-specific measurement reporting), determines valid frequency measurement results, and composes and stores the results to be reported. That is, even if configuration information for second frequency-specific SSB measurement for each frequency corresponding to the first frequency list is broadcast in the system information, the information in the RRCRelease message is prioritized and applied because the cell is a cell that has received RRCRelease. Specifically, in method 1-1-1, the UE performs frequency measurement by reflecting configuration information for first frequency-specific SSB measurement (e.g., SMTC period, offset, and duration) set for the frequency to be measured based on the reference timing of the serving cell on which the UE camped through the cell selection or reselection procedure (e.g., frequency 4 (13-03)). In another method, the UE may store the reference timing of the cell from which the UE received the RRCRelease message and perform measurement by applying configuration information for first frequency-specific SSB measurement or configuration information for second frequency-specific SSB measurement based on the stored timing. When measuring a frequency, if there is no configuration information for first frequency-specific SSB measurement for the frequency to be measured and if there is no configuration information for second frequency-specific SSB measurement in the second frequency configuration information, the UE may not perform measurement on the frequency to reduce battery consumption.Alternatively, even if the UE does not have configuration information for first frequency-specific SSB measurement (e.g., SMTC period, offset, and duration) or second frequency-specific SSB measurement, it can synchronize with the frequency in the implementation, search for an SSB signal from scratch, and derive period, offset, and duration parameter values ​​to perform frequency measurement in RRC idle mode or RRC inactive mode. Alternatively, if there is no configuration information for first frequency-specific SSB measurement for a frequency in the first frequency list to be measured but second frequency configuration information received from the system information broadcasts second frequency-specific SSB measurement configuration information for the frequency, the UE can perform frequency measurement by reflecting the configuration information for second frequency-specific SSB measurement (e.g., SMTC period, offset, and duration) set for the frequency to be measured based on the reference timing of the serving cell on which it is camped through a cell selection or reselection procedure (e.g., frequency 4 (13-04)).

[0179] ◆2>If the first frequency configuration information received from the RRCRelease message does not include configuration information for the first frequency list, the terminal applies method 2-1 14-51 of the present invention, which will be described later. Specifically, the terminal performs frequency measurement by prioritizing the second frequency configuration information 14-20. Therefore, the terminal performs frequency measurement only on the frequencies set in the second frequency list (14-51, frequency 3 (14-03), frequency 4 (14-04), frequency 5 (14-05), frequency 6 (14-06), frequency 7 (14-07), frequency 8 (14-08)). The terminal performs frequency measurement by reflecting frequency measurement configuration information for each frequency set in the second frequency configuration information (e.g., threshold information serving as a standard for measuring and reporting by frequency, or configuration information for SSB measurement by second frequency, or a reporting method for measurement reporting by second frequency), determines valid frequency measurement results, and composes and stores the results to be reported. Specifically, in method 2-1, the UE performs frequency measurement based on the reference timing of the serving cell on which it camped through the cell selection or reselection procedure, reflecting configuration information (e.g., SMTC period, offset, and duration) for second frequency-specific SSB measurement set for the frequency to be measured. If there is no configuration information for second frequency-specific SSB measurement for the frequency to be measured, the UE does not perform measurement on the frequency to reduce battery consumption. Alternatively, even if there is no configuration information for second frequency-specific SSB measurement (e.g., SMTC period, offset, and duration), the UE can synchronize with the frequency in the implementation, search for an SSB signal from scratch, derive period, offset, and duration parameter values, and perform frequency measurement in RRC idle mode or RRC inactive mode. Alternatively, method 2-2 (14-52) can also be applied.

[0180] ■1> When the terminal moves from cell 1 where it received RRCRelease and caps on to a new cell 2 (13-53)

[0181] ◆2> The terminal performs frequency measurements by prioritizing the first frequency list in the first frequency configuration information 13-10. However, when performing measurements on the frequencies in the first frequency list, the terminal prioritizes the configuration information for SSB measurements for the second frequency over the configuration information for SSB measurements for the first frequency. Therefore, the terminal performs frequency measurements on frequency 1 (13-01), frequency 2 (13-02), frequency 3 (13-03), frequency 4 (13-04), frequency 5 (13-05), and frequency 6 (13-06) for the frequencies (13-51) set in the first frequency list, and performs frequency measurements by reflecting frequency measurement configuration information for each frequency set in the first frequency configuration information (e.g., threshold information serving as a standard for measuring and reporting by frequency, or configuration information for SSB measurements for the second frequency, or configuration information for SSB measurements for the first frequency, or a reporting method for measuring and reporting by the first frequency), determines valid frequency measurement results, and composes and stores the results to be reported. Specifically, if the terminal receives configuration information for first frequency-based SSB measurement for a target frequency corresponding to the first frequency list, but if configuration information for second frequency-based SSB measurement for the target frequency is broadcast in the system information in new cell 2, the terminal prioritizes the configuration information for second frequency-based SSB measurement broadcast in the system information and applies it to the frequency to perform frequency measurement. That is, in the 1-1-1 method, if there is configuration information for second frequency-based SSB measurement (e.g., SMTC period, offset, and duration) set for the frequency to be measured based on the reference timing of the serving cell on which the terminal camped through the cell selection or reselection procedure, the terminal performs frequency measurement reflecting this information (e.g., frequency 4 (13-04)). This is because, when the terminal moves and camps on new cell 2, the configuration information for second frequency-based SSB measurement broadcast in new cell 2 is likely to be more accurate than the configuration information for first frequency-based SSB measurement received in previous cell 1. Also, if synchronization does not apply to each cell due to the implementation of the base station, the system information of the new cell 2 is followed, so that problems due to asynchronization between cells do not occur.When measuring a frequency, if there is no configuration information for SSB measurement for a first frequency for the frequency to be measured and no configuration information for SSB measurement for a second frequency for the second frequency configuration information, the terminal does not perform measurement on the frequency to reduce battery consumption. Alternatively, even if there is no configuration information for SSB measurement for a first frequency (e.g., SMTC period, offset, duration) or SSB measurement for a second frequency, the terminal can synchronize with the frequency in the implementation, search for an SSB signal from the beginning, derive period, offset, and duration parameter values, and perform frequency measurement in RRC idle mode or RRC inactive mode. Alternatively, if configuration information for second frequency-specific SSB measurement for a frequency in the first frequency list to be measured is not broadcast in the system information but the first frequency configuration information received from the RRCRelease message includes first frequency-specific SSB measurement configuration information for the frequency, the UE can perform frequency measurement by reflecting the configuration information for first frequency-specific SSB measurement (e.g., SMTC period, offset, and duration) set for the frequency to be measured based on the reference timing of the serving cell on which the UE is camped through the cell selection or reselection procedure (e.g., frequency 4 (13-04)). (Alternatively, the UE can store the reference timing of the cell from which the RRCRelease message is received and perform measurement by applying the configuration information for first frequency-specific SSB measurement or the configuration information for second frequency-specific SSB measurement based on the stored timing.) Alternatively, method 1-1 or method 1-2 proposed in the present invention can be applied.

[0182] ◆2>If the first frequency configuration information received from the RRCRelease message does not include configuration information for the first frequency list, the terminal applies a method 2-1 (14-51) of the present invention, which will be described later. Specifically, the terminal performs frequency measurement by prioritizing the second frequency configuration information 14-20. Therefore, the terminal performs frequency measurement only on the frequencies set in the second frequency list (14-51, frequency 3 (14-03), frequency 4 (14-04), frequency 5 (14-05), frequency 6 (14-06), frequency 7 (14-07), frequency 8 (14-08)). The terminal performs frequency measurement by reflecting frequency measurement configuration information for each frequency set in the second frequency configuration information (e.g., threshold information serving as a standard for measuring and reporting by frequency, or configuration information for SSB measurement by second frequency, or a reporting method for measurement reporting by second frequency), determines valid frequency measurement results, and composes and stores the results to be reported. Specifically, in method 2-1, the UE performs frequency measurement based on the reference timing of the serving cell on which it camped through the cell selection or reselection procedure, reflecting configuration information (e.g., SMTC period, offset, and duration) for second frequency-specific SSB measurement set for the frequency to be measured. If there is no configuration information for second frequency-specific SSB measurement for the frequency to be measured, the UE does not perform measurement on the frequency to reduce battery consumption. Alternatively, even if there is no configuration information for second frequency-specific SSB measurement (e.g., SMTC period, offset, and duration), the UE can synchronize with the frequency in the implementation, search for an SSB signal from scratch, derive period, offset, and duration parameter values, and perform frequency measurement in RRC idle mode or RRC inactive mode. Alternatively, method 2-2 (14-52) can also be applied.

[0183] FIG. 14 illustrates a second example of an efficient RRC idle mode or RRC inactive mode frequency measurement method according to an embodiment of the present invention.

[0184] In FIG. 14, the base station or cell configures the configuration information for RRC idle mode or RRC inactive mode frequency measurement in the terminal using first frequency measurement configuration information 14-10 in the RRCRelease message or second frequency measurement configuration information 14-20 in the system information.

[0185] When the UE receives an RRCRelease message and first frequency configuration information is included, the UE drives a timer by reflecting first timer value information in the first frequency configuration information and starts RRC idle mode or RRC inactive mode frequency measurement (early measurement). Furthermore, if the first frequency configuration information includes first region configuration information, the UE checks the identifier of the cell to be camped on when performing a cell selection or reselection procedure to determine whether to perform RRC idle mode or RRC inactive mode frequency measurement (early measurement). If the first frequency configuration information does not include first frequency list information to be measured and second frequency configuration information is broadcast in the system information of the cell camped on through the cell selection or reselection procedure, the UE performs RRC idle mode or RRC inactive mode frequency measurement based on the second frequency configuration information (e.g., second frequency list information), stores valid measurement results, and subsequently reports the measurement results to the network in the manner shown in FIG. 6 or 7 when establishing an RRC connection.

[0186] In a second specific embodiment of the efficient frequency measurement method in RRC idle mode or RRC inactive mode proposed in Fig. 14, the UE receives first frequency configuration information through an RRCRelease message, transitions to RRC idle mode or RRC inactive mode, performs frequency measurement, and receives second frequency configuration information from system information of the camped-on cell through a cell selection or reselection procedure.

[0187] In a second embodiment of the present invention, a terminal receives first frequency configuration information or second frequency configuration information, and when performing frequency measurement in RRC idle mode or RRC inactive mode, the terminal prioritizes the second frequency configuration information and performs frequency measurement based only on the second frequency configuration information. Alternatively, for configuration information not included in the second frequency configuration information, the terminal may perform frequency measurement taking the first frequency configuration information into consideration.

[0188] For example, the terminal receives the first frequency configuration information 14-10 by receiving an RRCRelease message from cell 1, and receives the second frequency configuration information 14-20 in the system information from cell 1 or a new cell 2 through a cell selection or reselection procedure after transitioning to RRC idle mode or RRC inactive mode.

[0189] The first frequency list of the first frequency setting information 14-10 includes frequency 1 (14-01), frequency 2 (14-02), frequency 3 (14-03), frequency 4 (14-04), frequency 5 (14-05), and frequency 6 (14-06) as targets for frequency measurement, and threshold information that serves as a standard for measuring and reporting only for frequency 1 (14-01), frequency 2 (14-02), frequency 3 (14-03), and frequency 5 (14-05) among the set frequencies, or setting information for first frequency-specific SSB measurement, or a reporting method for first frequency-specific measurement reporting is set.

[0190] The second frequency list of the second frequency setting information 14-20 includes frequency 3 (14-03), frequency 4 (14-04), frequency 5 (14-05), frequency 6 (14-06), frequency 7 (14-07), and frequency 8 (14-08) as targets for frequency measurement, and threshold information that serves as a standard for measuring and reporting only for frequency 3 (14-03), frequency 4 (14-04), frequency 7 (14-07), and frequency 8 (14-08) among the set frequencies, or setting information for second frequency-specific SSB measurement, or a reporting method for second frequency-specific measurement reporting is set.

[0191] When the terminal receives the first frequency configuration information 14-10 or the second frequency configuration information 14-20, it selects the frequency on which to perform RRC idle mode or RRC inactive mode frequency measurements, and applies one of the following methods to determine the frequency configuration to apply to each frequency.

[0192] - Method 2-1 14-51: The terminal performs frequency measurement by prioritizing the second frequency configuration information 14-20. Therefore, the terminal performs frequency measurement only on the frequencies set in the second frequency list (14-51, frequency 3 (14-03), frequency 4 (14-04), frequency 5 (14-05), frequency 6 (14-06), frequency 7 (14-07), frequency 8 (14-08)), and performs frequency measurement by reflecting frequency measurement configuration information for each frequency set in the second frequency configuration information (e.g., threshold information serving as a standard for measuring and reporting by frequency, or configuration information for SSB measurement by second frequency, or a reporting method for measurement reporting by second frequency), determines valid frequency measurement results, and composes and stores the results to be reported. Specifically, in method 2-1, the UE performs frequency measurement by reflecting configuration information (e.g., SMTC period, offset, and duration) for second frequency-specific SSB measurement set for the frequency to be measured based on the reference timing of the serving cell on which it camped through a cell selection or reselection procedure. If there is no configuration information for second frequency-specific SSB measurement for the frequency to be measured, the UE does not perform measurement on the frequency to reduce battery consumption. Alternatively, even if there is no configuration information for second frequency-specific SSB measurement (e.g., SMTC period, offset, and duration), the UE can synchronize with the frequency in the implementation, search for an SSB signal from scratch, derive period, offset, and duration parameter values, and perform frequency measurement in RRC idle mode or RRC inactive mode.

[0193] - Method 2-2 14-52: The terminal performs frequency measurement by prioritizing the second frequency configuration information 14-10. Therefore, the terminal performs frequency measurement only on the frequencies set in the second frequency list (14-52, frequency 3 (14-03), frequency 4 (14-04), frequency 5 (14-05), frequency 6 (14-06), frequency 7 (14-07), frequency 8 (14-08)), and performs frequency measurement by reflecting frequency measurement configuration information for each frequency set in the second frequency configuration information (e.g., threshold information serving as a standard for measuring and reporting by frequency, or configuration information for SSB measurement by second frequency, or a reporting method for measurement reporting by second frequency), determines valid frequency measurement results, and composes and stores the results to be reported. Specifically, in method 2-2, the UE performs frequency measurement by reflecting configuration information (e.g., SMTC period, offset, and duration) for second frequency-specific SSB measurement set for the frequency to be measured based on the reference timing of the serving cell camped on through the cell selection or reselection procedure. If there is no configuration information for second frequency-specific SSB measurement for the frequency to be measured but the UE receives first frequency-specific SSB measurement configuration information for the frequency in the first frequency configuration information received from the RRCRelease message, the UE performs frequency measurement by reflecting configuration information (e.g., SMTC period, offset, and duration) for first frequency-specific SSB measurement set for the frequency to be measured based on the reference timing of the serving cell camped on through the cell selection or reselection procedure (e.g., frequency 5 (14-05)). If there is no configuration information for first frequency-specific SSB measurement for the frequency to be measured and the second frequency configuration information does not contain configuration information for second frequency-specific SSB measurement, the UE does not perform measurement on the frequency to reduce battery consumption.In another method, even if there is no configuration information for SSB measurement for a first frequency (e.g., smtc period, offset, duration) or SSB measurement for a second frequency, the terminal can synchronize to the frequency in the implementation, search for an SSB signal from the beginning, derive period, offset, and duration parameter values, and perform frequency measurement in RRC idle mode or RRC inactive mode.

[0194] FIG. 15 illustrates a third example of an efficient RRC idle mode or RRC inactive mode frequency measurement method according to an embodiment of the present invention.

[0195] In FIG. 15, the base station or cell configures the configuration information for RRC idle mode or RRC inactive mode frequency measurement in the terminal using first frequency measurement configuration information 15-10 in the RRCRelease message or second frequency measurement configuration information 15-20 in the system information.

[0196] When the UE receives an RRCRelease message and first frequency configuration information is included, the UE drives a timer by reflecting first timer value information in the first frequency configuration information and starts RRC idle mode or RRC inactive mode frequency measurement (early measurement). If the first frequency configuration information includes first region configuration information, the UE checks the identifier of the cell on which the UE will camp when performing a cell selection or reselection procedure to determine whether to perform RRC idle mode or RRC inactive mode frequency measurement (early measurement). If the first frequency configuration information does not include first frequency list information on which measurements must be performed, the UE performs RRC idle mode or RRC inactive mode frequency measurement based on the second frequency configuration information (e.g., second frequency list information) when second frequency configuration information is broadcast in the system information of the cell on which the UE is camped through the cell selection or reselection procedure, stores valid measurement results, and subsequently reports the measurement results to the network in the manner shown in FIG. 6 or 7 when establishing an RRC connection.

[0197] In a third specific embodiment of the efficient frequency measurement method in RRC idle mode or RRC inactive mode proposed in Fig. 15, a terminal receives first frequency configuration information through an RRCRelease message, transitions to RRC idle mode or RRC inactive mode, performs frequency measurement, and receives second frequency configuration information from system information of the camped-on cell through a cell selection or reselection procedure.

[0198] In a third embodiment of the present invention, a terminal receives first frequency configuration information or second frequency configuration information, and when performing frequency measurement in RRC idle mode or RRC inactive mode, compares the first frequency configuration information with the second frequency configuration information and performs frequency measurement on a frequency corresponding to an intersection of the first frequency list and the second frequency list.The terminal then performs frequency measurement based on the first frequency configuration information or the second frequency configuration information when performing frequency measurement on a frequency corresponding to the intersection.In another method, frequency measurement can be performed for configuration information not included in the first frequency configuration information by taking into account the second frequency configuration information, and frequency measurement can be performed for configuration information not included in the second frequency configuration information by taking into account the first frequency configuration information.

[0199] For example, the terminal receives the first frequency configuration information 15-10 by receiving an RRCRelease message from cell 1, and receives the second frequency configuration information 15-20 in the system information from cell 1 or a new cell 2 through a cell selection or reselection procedure after transitioning to RRC idle mode or RRC inactive mode.

[0200] The first frequency list of the first frequency setting information 15-10 includes frequency 1 (15-01), frequency 2 (15-02), frequency 3 (15-03), frequency 4 (15-04), frequency 5 (15-05), and frequency 6 (15-06) as targets for frequency measurement, and threshold information that serves as a standard for measuring and reporting only for frequency 1 (15-01), frequency 2 (15-02), frequency 3 (15-03), and frequency 5 (15-05) among the set frequencies, or setting information for first frequency-specific SSB measurement, or a reporting method for first frequency-specific measurement reporting is set.

[0201] The second frequency list of the second frequency setting information 15-20 includes frequency 3 (15-03), frequency 4 (15-04), frequency 5 (15-05), frequency 6 (15-06), frequency 7 (15-07), and frequency 8 (15-08) as targets for frequency measurement, and threshold information that serves as a standard for measuring and reporting only for frequency 3 (15-03), frequency 4 (15-04), frequency 7 (15-07), and frequency 8 (15-08) among the set frequencies, or setting information for second frequency-specific SSB measurement, or a reporting method for second frequency-specific measurement reporting is set.

[0202] When the terminal receives the first frequency configuration information 15-10 or the second frequency configuration information 15-20, it selects the frequency on which to perform RRC idle mode or RRC inactive mode frequency measurement, and applies one of the following methods to determine the frequency configuration to apply to each frequency.

[0203] -3-1 Method 15-51: When the terminal receives the first frequency configuration information 15-10 and the second frequency configuration information 15-20, the terminal compares the first frequency list information of the first frequency configuration information with the second frequency list information of the second frequency configuration information, selects a frequency corresponding to the intersection, and performs frequency measurement as the measurement target. Therefore, the terminal performs frequency measurement only on frequencies 15-30 (15-51, frequency 3 (15-03), frequency 4 (15-04), frequency 5 (15-05), frequency 6 (15-06)) corresponding to the intersection of the first frequency list and the second frequency list, performs frequency measurement reflecting frequency measurement configuration information for each frequency set in the first frequency configuration information (e.g., threshold information serving as a standard for measuring and reporting by frequency, or configuration information for SSB measurement by the first frequency, or a reporting method for measurement reporting by the first frequency), determines valid frequency measurement results, composes and stores the results to be reported. Specifically, in method 3-1, the UE performs frequency measurement by reflecting configuration information (e.g., SMTC period, offset, and duration) for the first frequency-specific SSB measurement set for the frequency to be measured based on the reference timing of the serving cell on which it camped through a cell selection or reselection procedure. If there is no configuration information for the first frequency-specific SSB measurement for the frequency to be measured, the UE does not perform measurement on the frequency to reduce battery consumption. Alternatively, even if there is no configuration information for the first frequency-specific SSB measurement (e.g., SMTC period, offset, and duration), the UE can synchronize with the frequency in its implementation, search for an SSB signal from scratch, derive period, offset, and duration parameter values, and perform frequency measurement in RRC idle mode or RRC inactive mode. Alternatively, the UE can store the reference timing of the cell that received the RRCRelease message and perform measurement by applying configuration information for the first frequency-specific SSB measurement based on the stored timing. In the 3-1 method, the terminal performs frequency measurement based only on the first frequency setting information, so there is no need to read a lot of system information, which reduces battery consumption of the terminal.

[0204] -3-2 Method 15-52: When the terminal receives the first frequency configuration information 15-10 and the second frequency configuration information 15-20, the terminal compares the first frequency list information of the first frequency configuration information with the second frequency list information of the second frequency configuration information, selects a frequency corresponding to the intersection, and performs frequency measurement on the selected frequency. Therefore, the terminal performs frequency measurement only on frequencies 15-30 (15-52, frequency 3 (15-03), frequency 4 (15-04), frequency 5 (15-05), frequency 6 (15-06)) corresponding to the intersection of the first frequency list and the second frequency list. The terminal performs frequency measurement by reflecting frequency measurement configuration information (e.g., threshold information serving as a standard for measuring and reporting by frequency, or configuration information for SSB measurement by the first frequency, or a reporting method for measurement reporting by the first frequency) for each frequency set in the first frequency configuration information, determines valid frequency measurement results, and composes and stores the results to be reported. Specifically, in method 3-2, the UE performs frequency measurement by reflecting configuration information (e.g., SMTC period, offset, and duration) for first frequency-specific SSB measurement set for the frequency to be measured based on the reference timing of the serving cell on which it is camped through a cell selection or reselection procedure. If there is no configuration information for first frequency-specific SSB measurement for the frequency to be measured but second frequency-specific SSB measurement configuration information for the frequency is broadcast in the second frequency configuration information received from the system information, the UE performs frequency measurement by reflecting configuration information (e.g., SMTC period, offset, and duration) for second frequency-specific SSB measurement set for the frequency to be measured based on the reference timing of the serving cell on which it is camped through a cell selection or reselection procedure (e.g., frequency 4 (15-04)). If there is no configuration information for first frequency-specific SSB measurement for the frequency to be measured and the second frequency configuration information does not contain configuration information for second frequency-specific SSB measurement, the UE does not perform measurement on the frequency to reduce battery consumption.In another method, even if there is no configuration information for SSB measurement for a first frequency (e.g., smtc period, offset, duration) or SSB measurement for a second frequency, the terminal can synchronize to the frequency in the implementation, search for an SSB signal from the beginning, derive period, offset, and duration parameter values, and perform frequency measurement in RRC idle mode or RRC inactive mode.

[0205] - 3-3 Method 15-53: When the terminal receives the first frequency configuration information 15-10 and the second frequency configuration information 15-20, the terminal compares the first frequency list information of the first frequency configuration information with the second frequency list information of the second frequency configuration information, selects a frequency corresponding to the intersection, and performs frequency measurement on the selected frequency. Therefore, the terminal performs frequency measurement only on frequencies 15-30 (15-53, frequency 3 (15-03), frequency 4 (15-04), frequency 5 (15-05), frequency 6 (15-06)) corresponding to the intersection of the first frequency list and the second frequency list. The terminal performs frequency measurement by reflecting frequency measurement configuration information (e.g., threshold information serving as a standard for measuring and reporting by frequency, or configuration information for SSB measurement by second frequency, or a reporting method for measurement reporting by second frequency) for each frequency set in the second frequency configuration information, determines valid frequency measurement results, and composes and stores the results to be reported. Specifically, in method 3-3, the UE performs frequency measurement by reflecting configuration information (e.g., SMTC period, offset, and duration) for second frequency-specific SSB measurement set for the frequency to be measured based on the reference timing of the serving cell on which it is camped through a cell selection or reselection procedure. If there is no configuration information for second frequency-specific SSB measurement for the frequency to be measured, the UE does not perform measurement on the frequency to reduce battery consumption. Alternatively, even if there is no configuration information for second frequency-specific SSB measurement (e.g., SMTC period, offset, and duration), the UE can synchronize with the frequency in the implementation, search for an SSB signal from scratch, derive period, offset, and duration parameter values, and perform frequency measurement in RRC idle mode or RRC inactive mode.

[0206] -3-4 Method 15-54: When the terminal receives the first frequency configuration information 15-10 and the second frequency configuration information 15-20, the terminal compares the first frequency list information of the first frequency configuration information with the second frequency list information of the second frequency configuration information, selects a frequency corresponding to the intersection, and performs frequency measurement on the selected frequency. Therefore, the terminal performs frequency measurement only on frequencies 15-30 (15-54, frequency 3 (15-03), frequency 4 (15-04), frequency 5 (15-05), frequency 6 (15-06)) corresponding to the intersection of the first frequency list and the second frequency list. The terminal performs frequency measurement by reflecting frequency measurement configuration information (e.g., threshold information serving as a standard for measuring and reporting by frequency, or configuration information for SSB measurement by second frequency, or a reporting method for measurement reporting by second frequency) for each frequency set in the second frequency configuration information, determines valid frequency measurement results, and composes and stores the results to be reported. Specifically, in method 3-4, the UE performs frequency measurement by reflecting configuration information (e.g., SMTC period, offset, and duration) for second frequency-specific SSB measurement set for the frequency to be measured based on the reference timing of the serving cell camped on through the cell selection or reselection procedure. If there is no configuration information for second frequency-specific SSB measurement for the frequency to be measured but the UE receives first frequency-specific SSB measurement configuration information for the frequency in the first frequency configuration information received from the RRCRelease message, the UE performs frequency measurement by reflecting configuration information (e.g., SMTC period, offset, and duration) for first frequency-specific SSB measurement set for the frequency to be measured based on the reference timing of the serving cell camped on through the cell selection or reselection procedure (e.g., frequency 5 (15-05)). If there is no configuration information for second frequency-specific SSB measurement for the frequency to be measured and the first frequency configuration information does not contain configuration information for first frequency-specific SSB measurement, the UE does not perform measurement on the frequency to reduce battery consumption.In another method, even if there is no configuration information for SSB measurement for a first frequency (e.g., smtc period, offset, duration) or SSB measurement for a second frequency, the terminal can synchronize to the frequency in the implementation, search for an SSB signal from the beginning, derive period, offset, and duration parameter values, and perform frequency measurement in RRC idle mode or RRC inactive mode.

[0207] FIG. 16 illustrates a fourth example of an efficient RRC idle mode or RRC inactive mode frequency measurement method according to an embodiment of the present invention.

[0208] In FIG. 16, the base station or cell configures the configuration information for RRC idle mode or RRC inactive mode frequency measurement in the terminal using first frequency measurement configuration information 16-10 in the RRCRelease message or second frequency measurement configuration information 16-20 in the system information.

[0209] When the UE receives an RRCRelease message and first frequency configuration information is included, the UE drives a timer by reflecting first timer value information in the first frequency configuration information and starts RRC idle mode or RRC inactive mode frequency measurement (early measurement). If the first frequency configuration information includes first region configuration information, the UE checks the identifier of the cell on which the UE will camp when performing a cell selection or reselection procedure to determine whether to perform RRC idle mode or RRC inactive mode frequency measurement (early measurement). If the first frequency configuration information does not include first frequency list information that must be measured, the UE performs RRC idle mode or RRC inactive mode frequency measurement based on the second frequency configuration information (e.g., second frequency list information) when second frequency configuration information is broadcast in the system information of the cell on which the UE is camped through the cell selection or reselection procedure, stores valid measurement results, and subsequently reports the measurement results to the network in the manner shown in FIG. 6 or 7 when establishing an RRC connection.

[0210] In a fourth specific embodiment of the efficient frequency measurement method in RRC idle mode or RRC inactive mode proposed in Fig. 16, a terminal receives first frequency configuration information through an RRCRelease message, transitions to RRC idle mode or RRC inactive mode, performs frequency measurement, and receives second frequency configuration information from system information of the camped-on cell through a cell selection or reselection procedure.

[0211] In a fourth embodiment of the present invention, a terminal receives first frequency configuration information or second frequency configuration information, and when performing frequency measurement in RRC idle mode or RRC inactive mode, compares the first frequency configuration information with the second frequency configuration information and performs frequency measurement on frequencies corresponding to a union of the first frequency list and the second frequency list.The terminal then performs frequency measurement on frequencies corresponding to the union based on the first frequency configuration information or the second frequency configuration information.In another method, for configuration information not included in the first frequency configuration information, frequency measurement is performed taking into account the second frequency configuration information, and for configuration information not included in the second frequency configuration information, frequency measurement is performed taking into account the first frequency configuration information.

[0212] For example, the terminal receives the first frequency configuration information 16-10 by receiving an RRCRelease message from cell 1, and receives the second frequency configuration information 16-20 in the system information from cell 1 or a new cell 2 through a cell selection or reselection procedure after transitioning to RRC idle mode or RRC inactive mode.

[0213] The first frequency list of the first frequency setting information 16-10 includes frequency 1 (16-01), frequency 2 (16-02), frequency 3 (16-03), frequency 4 (16-04), frequency 5 (16-05), and frequency 6 (16-06) as targets for frequency measurement, and threshold information that serves as a standard for measuring and reporting only for frequency 1 (16-01), frequency 2 (16-02), frequency 3 (16-03), and frequency 5 (16-05) among the set frequencies, or setting information for first frequency-specific SSB measurement, or a reporting method for first frequency-specific measurement reporting is set.

[0214] The second frequency list of the second frequency setting information 16-20 includes frequency 3 (16-03), frequency 4 (16-04), frequency 5 (16-05), frequency 6 (16-06), frequency 7 (16-07), and frequency 8 (16-08) as targets for frequency measurement, and threshold information that serves as a standard for measuring and reporting only for frequency 3 (16-03), frequency 4 (16-04), frequency 7 (16-07), and frequency 8 (16-08) among the set frequencies, or setting information for second frequency-specific SSB measurement, or a reporting method for second frequency-specific measurement reporting is set.

[0215] When the terminal receives the first frequency configuration information 16-10 or the second frequency configuration information 16-20, it selects the frequency on which to perform RRC idle mode or RRC inactive mode frequency measurement, and applies one of the following methods to determine the frequency configuration to apply to each frequency.

[0216] -4-1 Method 16-51: When the terminal receives the first frequency setting information 16-10 and the second frequency setting information 16-20, it compares the first frequency list information of the first frequency setting information with the second frequency list information of the second frequency setting information, selects the frequency corresponding to the union, and performs frequency measurement on that frequency as the measurement target. Therefore, the terminal performs frequency measurement on frequencies (6-10, 16-20, 16-30) (16-51, frequency 1 (16-01), frequency 2 (16-02), frequency 3 (16-03), frequency 4 (16-04), frequency 5 (16-05), frequency 6 (16-06), frequency 7 (16-07), frequency 8 (16-08)) corresponding to the union of the first frequency list and the second frequency list, and performs frequency measurement by reflecting frequency measurement setting information (e.g., threshold information serving as a standard for measuring and reporting by frequency, or setting information for SSB measurement by the first frequency, or a reporting method for measurement reporting by the first frequency) for each frequency set in the first frequency setting information or the second frequency setting information, determines valid frequency measurement results, and composes and stores the results to be reported. Specifically, in method 4-1, the UE performs frequency measurement by reflecting configuration information for SSB measurement for a first frequency (e.g., SMTC period, offset, and duration) set for a frequency to be measured in a first frequency list based on the reference timing of a serving cell on which the UE is camped through a cell selection or reselection procedure, or by reflecting configuration information for SSB measurement for a second frequency set for a frequency to be measured in a second frequency list. In method 4-1, the UE preferentially applies the first frequency configuration information to frequencies corresponding to the intersection of the first and second frequency lists, and if both the first and second frequency configuration information are available for a frequency to be measured, the UE preferentially applies the first frequency configuration information (frequencies 3, 16-03, and 16-51). If there is no configuration information for SSB measurement for a first frequency for a frequency to be measured in the first frequency list, or if there is no configuration information for SSB measurement for a second frequency for a frequency to be measured in the second frequency list, the terminal does not perform measurement on the frequency to reduce battery consumption.In another method, even if there is no configuration information for SSB measurement for a first frequency for a frequency to be measured in the first frequency list, or there is no configuration information for SSB measurement for a second frequency for a frequency to be measured in the second frequency list, the terminal can synchronize with the frequency in the implementation, search for an SSB signal from the beginning, derive period, offset, and duration parameter values, and perform frequency measurement in RRC idle mode or RRC inactive mode.

[0217] -4-2 Method 16-52: When the terminal receives the first frequency setting information 16-10 and the second frequency setting information 16-20, it compares the first frequency list information of the first frequency setting information with the second frequency list information of the second frequency setting information, selects the frequency corresponding to the union, and performs frequency measurement on that frequency as the measurement target. Therefore, the terminal performs frequency measurement on frequencies (16-10, 16-20, 16-30) (16-52, frequency 1 (16-01), frequency 2 (16-02), frequency 3 (16-03), frequency 4 (16-04), frequency 5 (16-05), frequency 6 (16-06), frequency 7 (16-07), frequency 8 (16-08)) corresponding to the union of the first frequency list and the second frequency list, and performs frequency measurement by reflecting frequency measurement setting information (e.g., threshold information serving as a standard for measuring and reporting by frequency, or setting information for SSB measurement by the first frequency, or a reporting method for measurement reporting by the first frequency) for each frequency set in the first frequency setting information or the second frequency setting information, determines valid frequency measurement results, and composes and stores the results to be reported. Specifically, in method 4-2, the UE performs frequency measurement by reflecting configuration information for SSB measurement for a first frequency (e.g., SMTC period, offset, and duration) set for a frequency to be measured in a first frequency list based on the reference timing of a serving cell on which the UE is camped through a cell selection or reselection procedure, or by reflecting configuration information for SSB measurement for a second frequency set for a frequency to be measured in a second frequency list. In method 4-2, the UE preferentially applies the first frequency configuration information to frequencies corresponding to the intersection of the first and second frequency lists, and if both the first and second frequency configuration information are available for a frequency to be measured, preferentially applies the first frequency configuration information (frequencies 3, 16-03, and 16-52).If there is no configuration information for the first frequency-specific SSB measurement for the frequency to be measured but the second frequency configuration information received from the system information broadcasts the second frequency-specific SSB measurement configuration information for the frequency, the UE performs frequency measurement by reflecting the configuration information (e.g., SMTC period, offset, and duration) for the second frequency-specific SSB measurement set for the frequency to be measured based on the reference timing of the serving cell on which it is camped through the cell selection or reselection procedure (e.g., frequency 4 (16-04)). Also, if there is no configuration information for the second frequency-specific SSB measurement for the frequency to be measured but the UE receives the first frequency-specific SSB measurement configuration information for the frequency in the first frequency configuration information received from the RRCRelease message, the UE performs frequency measurement by reflecting the configuration information (e.g., SMTC period, offset, and duration) for the first frequency-specific SSB measurement set for the frequency to be measured based on the reference timing of the serving cell on which it is camped through the cell selection or reselection procedure (e.g., frequency 5 (15-05)). When measuring a frequency, if there is no configuration information for SSB measurement for the second frequency for a frequency to be measured and there is no configuration information for SSB measurement for the first frequency in the first frequency configuration information, the UE does not perform measurement for the frequency to reduce battery consumption. When there is no configuration information for SSB measurement for the first frequency for a frequency to be measured and there is no configuration information for SSB measurement for the second frequency in the second frequency configuration information, the UE does not perform measurement for the frequency to reduce battery consumption. Alternatively, even if there is no configuration information for SSB measurement for the first frequency (e.g., SMTC period, offset, duration) or SSB measurement for the second frequency, the UE can synchronize with the frequency in its implementation, search for an SSB signal from scratch, derive period, offset, and duration parameter values, and perform frequency measurement in RRC idle mode or RRC inactive mode.

[0218] -4-3 Method 16-53: When the terminal receives the first frequency setting information 16-10 and the second frequency setting information 16-20, it compares the first frequency list information of the first frequency setting information with the second frequency list information of the second frequency setting information, selects the frequency corresponding to the union, and performs frequency measurement on that frequency as the measurement target. Therefore, the terminal performs frequency measurement on frequencies (16-10, 16-20, 16-30) (16-53, frequency 1 (16-01), frequency 2 (16-02), frequency 3 (16-03), frequency 4 (16-04), frequency 5 (16-05), frequency 6 (16-06), frequency 7 (16-07), frequency 8 (16-08)) corresponding to the union of the first frequency list and the second frequency list, and performs frequency measurement by reflecting frequency measurement setting information (e.g., threshold information serving as a standard for measuring and reporting by frequency, or setting information for SSB measurement by the first frequency, or a reporting method for measurement reporting by the first frequency) for each frequency set in the first frequency setting information or the second frequency setting information, determines valid frequency measurement results, and composes and stores the results to be reported. Specifically, in the 4-3 method, the UE performs frequency measurement by reflecting configuration information for SSB measurement for a first frequency (e.g., SMTC period, offset, and duration) set for a frequency to be measured in a first frequency list based on the reference timing of a serving cell on which the UE is camped through a cell selection or reselection procedure, or by reflecting configuration information for SSB measurement for a second frequency set for a frequency to be measured in a second frequency list. In the 4-3 method, the UE preferentially applies the second frequency configuration information to frequencies corresponding to the intersection of the first and second frequency lists, and if both the first and second frequency configuration information are available for a frequency to be measured, preferentially applies the second frequency configuration information (frequencies 3, 16-03, and 16-53). If there is no configuration information for SSB measurement for a first frequency for a frequency to be measured in the first frequency list, or if there is no configuration information for SSB measurement for a second frequency for a frequency to be measured in the second frequency list, the terminal does not perform measurement on the frequency to reduce battery consumption.In another method, even if there is no configuration information for SSB measurement for a first frequency for a frequency to be measured in a first frequency list, or there is no configuration information for SSB measurement for a second frequency for a frequency to be measured in a second frequency list, the terminal can synchronize with the frequency in the implementation, search for an SSB signal from the beginning, derive period, offset, and duration parameter values, and perform frequency measurement in RRC idle mode or RRC inactive mode.

[0219] -4-4 Method 16-54: When the terminal receives the first frequency setting information 16-10 and the second frequency setting information 16-20, it compares the first frequency list information of the first frequency setting information with the second frequency list information of the second frequency setting information, selects the frequency corresponding to the union, and performs frequency measurement on that frequency as the measurement target. Therefore, the terminal performs frequency measurement on the frequencies (16-10, 16-20, 16-30) (16-54, frequency 1 (16-01), frequency 2 (16-02), frequency 3 (16-03), frequency 4 (16-04), frequency 5 (16-05), frequency 6 (16-06), frequency 7 (16-07), frequency 8 (16-08)) corresponding to the union of the first frequency list and the second frequency list, and performs frequency measurement by reflecting frequency measurement setting information (e.g., threshold information serving as a standard for measuring and reporting by frequency, or setting information for SSB measurement by the first frequency, or a reporting method for measurement reporting by the first frequency) for each frequency set in the first frequency setting information or the second frequency setting information, determines valid frequency measurement results, and composes and stores the results to be reported. Specifically, in the 4-4 method, the UE performs frequency measurement by reflecting configuration information (e.g., SMTC period, offset, and duration) for SSB measurement for a first frequency that is set for a frequency to be measured in a first frequency list based on the reference timing of a serving cell that the UE camped on through a cell selection or reselection procedure, or by reflecting configuration information for SSB measurement for a second frequency that is set for a frequency to be measured in a second frequency list. In the 4-4 method, the UE preferentially applies the second frequency configuration information to a frequency that corresponds to the intersection of the first and second frequency lists, and when both the first and second frequency configuration information are available for a frequency to be measured, preferentially applies the second frequency configuration information (frequencies 3, 16-03, and 16-54).If there is no configuration information for the first frequency-specific SSB measurement for the frequency to be measured but the second frequency configuration information received from the system information broadcasts the second frequency-specific SSB measurement configuration information for the frequency, the UE performs frequency measurement by reflecting the configuration information (e.g., SMTC period, offset, and duration) for the second frequency-specific SSB measurement set for the frequency to be measured based on the reference timing of the serving cell on which it is camped through the cell selection or reselection procedure (e.g., frequency 4 (16-04)). Also, if there is no configuration information for the second frequency-specific SSB measurement for the frequency to be measured but the UE receives the first frequency-specific SSB measurement configuration information for the frequency in the first frequency configuration information received from the RRCRelease message, the UE performs frequency measurement by reflecting the configuration information (e.g., SMTC period, offset, and duration) for the first frequency-specific SSB measurement set for the frequency to be measured based on the reference timing of the serving cell on which it is camped through the cell selection or reselection procedure (e.g., frequency 5 (15-05)). When measuring a frequency, if there is no configuration information for SSB measurement for the second frequency for a frequency to be measured and there is no configuration information for SSB measurement for the first frequency in the first frequency configuration information, the UE does not perform measurement for the frequency to reduce battery consumption. When there is no configuration information for SSB measurement for the first frequency for a frequency to be measured and there is no configuration information for SSB measurement for the second frequency in the second frequency configuration information, the UE does not perform measurement for the frequency to reduce battery consumption. Alternatively, even if there is no configuration information for SSB measurement for the first frequency (e.g., SMTC period, offset, duration) or SSB measurement for the second frequency, the UE can synchronize with the frequency in its implementation, search for an SSB signal from scratch, derive period, offset, and duration parameter values, and perform frequency measurement in RRC idle mode or RRC inactive mode.

[0220] The first, second, third or fourth embodiment of the present invention is extended to be applied when a base station or a network sets configuration information for frequency measurement in RRC idle mode or RRC inactive mode only in the first frequency configuration information of RRCRelease. Also, the first, second, third or fourth embodiment of the present invention is extended to be applied when a base station or a network sets configuration information for frequency measurement in RRC idle mode or RRC inactive mode only in the second frequency configuration information of system information.

[0221] FIG. 17 is a diagram illustrating a method for a terminal to perform RRC idle mode or RRC inactive mode frequency measurement in a network that is not synchronized between different frequencies or cells according to an embodiment of the present invention.

[0222] 17, while transmitting and receiving data in RRC connected mode in current cell 117-01, the terminal receives an RRCRelease message from the base station of cell 1, transitions to RRC idle mode or RRC inactive mode, and moves while performing a cell selection or reselection procedure. The RRCRelease message includes first frequency configuration information. Also, in RRC idle mode or RRC inactive mode, the terminal performs a cell selection or reselection procedure while moving, capping on a suitable cell and acquiring system information. From the system information, the terminal receives second frequency measurement configuration information.

[0223] When the UE receives an RRCRelease message and first frequency configuration information is included, the UE drives a timer by reflecting first timer value information in the first frequency configuration information and starts frequency measurement (early measurement) in RRC idle mode or RRC inactive mode. Also, when first region configuration information is included in the first frequency configuration information, the UE checks the identifier of a cell to camp on when performing a cell selection or reselection procedure and determines whether to perform frequency measurement (early measurement) in RRC idle mode or RRC inactive mode.

[0224] When cell 1 (17-01) is in an area supporting the service, the terminal performs RRC idle mode or RRC inactive mode measurement based on the first frequency configuration information received from the RRCRelease message or the second frequency configuration information broadcast in the system information by cell 1. Specifically, the terminal performs RRC idle mode or RRC inactive mode measurement according to the first, second, third or fourth embodiment proposed in the present invention.

[0225] When the UE moves from cell 1 (17-01) to an area where cell 2 (17-02) supports services and camps on cell 2 (17-02), the UE performs RRC idle mode or RRC inactive mode measurement based on the first frequency configuration information previously received from the RRCRelease message of cell 1 (17-01) or the second frequency configuration information broadcast in the system information by cell 2. Specifically, the UE performs RRC idle mode or RRC inactive mode measurement according to the first, second, third, or fourth embodiment proposed in the present invention.

[0226] Next, a method for determining a reference timing when a terminal performs frequency measurement based on the first frequency configuration information when a base station or a network configures the first frequency configuration information in a terminal using an RRC message (e.g., an RRCRelease message or an RRCReconfiguration message) is proposed. The method for determining the reference timing proposed next in the present invention is extended and applied to the first, second, third, or fourth embodiment.

[0227] Reference Timing Determination Method 1: In Reference Timing Configuration Method 1, it is assumed that the network manages all frequencies in the network to be synchronized, or that synchronized information is broadcast in the system information broadcast in each cell. Therefore, the base station configures first frequency configuration information in the terminal using an RRC message, and the terminal performs RRC idle mode or RRC inactive mode frequency measurement by applying frequency-specific SSB configuration information based on the reference timing of a capped or synchronized cell (e.g., SFN0 of the cell) through a cell selection or reselection procedure when obtaining reference timing for RRC idle mode or RRC inactive mode frequency measurement.

[0228] Reference Timing Determination Method 2: In Reference Timing Configuration Method 2, the network does not assume that all frequencies in the network are synchronized. Therefore, when configuring first frequency configuration information to the terminal via an RRC message, the base station configures the first frequency configuration information by assuming the current cell as the reference timing. The terminal stores the reference timing of the cell (e.g., SFN0 of the cell) for which the first frequency configuration information was configured via an RRC message when obtaining reference timing for frequency measurement in RRC idle mode or RRC inactive mode, and performs frequency measurement in RRC idle mode or RRC inactive mode by applying frequency-specific SSB configuration information based on the stored reference timing.

[0229] Reference Timing Determination Method 3: In Reference Timing Configuration Method 3, the network does not assume that all frequencies in the network are managed to be synchronized. Therefore, the base station configures the first frequency configuration information by assuming the current cell or a cell included in the first region configuration information when configuring the first frequency configuration information for the terminal via an RRC message as the reference timing, and the terminal performs frequency measurement only if the cell it camps on through the cell selection or reselection procedure when performing frequency measurement in RRC idle mode or RRC inactive mode is the cell for which the first frequency configuration information is configured via the RRC message or a cell included in the first region information of the first frequency configuration information; otherwise, the terminal stops frequency measurement. Therefore, the terminal stores the reference timing of the cell (e.g., SFN0 of the cell) that sets the first frequency configuration information in the RRC message when taking the reference timing to perform frequency measurement, and performs frequency measurement in RRC idle mode or RRC inactive mode by applying frequency-specific SSB configuration information based on the reference timing of the serving cell (cell included in the first region information) that is set or camped on based on the stored reference timing.

[0230] Reference Timing Determination Method 4: In Reference Timing Configuration Method 4, it is not assumed that the network manages all frequencies in the network to be synchronized. Therefore, when configuring first frequency configuration information to the UE via an RRC message, the base station configures only frequencies that are synchronized across the entire network (assuming that each frequency included in the first frequency list is synchronized across the entire network) in the first frequency configuration information. Therefore, when performing frequency measurement in RRC idle mode or RRC inactive mode, the UE synchronizes with any cell of the frequency in the first frequency list configured in the first frequency configuration information, configures the frequency based on the reference timing of the synchronized cell, and applies SSB configuration information for each frequency to perform frequency measurement in RRC idle mode or RRC inactive mode.

[0231] Reference Timing Determination Method 5: In Reference Timing Configuration Method 5, the network does not assume that all frequencies in the network are synchronized. Therefore, when the base station configures first frequency configuration information to the terminal via an RRC message, it configures only the frequencies synchronized across the entire network (assuming that the frequencies included in the first frequency list are synchronized across the entire network) as the first frequency configuration information. Therefore, when the terminal performs frequency measurement in RRC idle mode or RRC inactive mode, it synchronizes with any cell of any frequency included in the first frequency list for the target frequency of the first frequency list configured in the first frequency configuration information, configures it based on the reference timing of the synchronized cell, and applies SSB configuration information for each frequency to perform frequency measurement in RRC idle mode or RRC inactive mode.

[0232] Reference Timing Determination Method 6: In Reference Timing Configuration Method 6, it is not assumed that the network manages all frequencies in the network to be synchronized. Therefore, when configuring first frequency configuration information to the UE via an RRC message, the base station separately configures the first frequency configuration information in a separate reference list with a reference frequency, cell, or region that is synchronized across the entire network (assuming that the frequencies included in the separate reference list are synchronized across the entire network). Therefore, when performing frequency measurement in RRC idle mode or RRC inactive mode, the UE synchronizes with any cell of any frequency included in the separate reference frequency list for the target frequency of the first frequency list configured in the first frequency configuration information, configures it based on the reference timing of the synchronized cell, and applies frequency-specific SSB configuration information to perform frequency measurement in RRC idle mode or RRC inactive mode.

[0233] The methods for determining reference timing (Method 1, Method 2, Method 3, Method 4, Method 5, Method 6) are extended and applied when performing a cell selection or reselection procedure based on the second frequency configuration information broadcast in the system information, when measuring neighboring cells, or when performing RRC idle mode or RRC inactive mode frequency measurement.

[0234] Furthermore, the present invention proposes a first terminal operation in which frequency measurement is performed in different ways depending on which RRC message contains the frequency measurement configuration information set in the terminal.

[0235] When an RRC connected mode UE receives an RRC message, if the RRC message is an RRCRelease message, it transitions to an RRC inactive mode or an RRC idle mode. If the RRC message includes frequency measurement configuration information (e.g., first frequency measurement configuration information for RRC idle mode or RRC inactive mode), the UE performs frequency measurement by applying ssb configuration information or smtc configuration information to the frequency to be measured based on the serving cell on which it is camped through the cell selection or reselection procedure.

[0236] When an RRC connected mode UE receives an RRC message, if the RRC message is an RRC Reconfiguration message, it performs frequency measurement in the RRC connected mode. If the RRC message includes frequency measurement configuration information (e.g., first frequency measurement configuration information for the RRC connected mode), the UE performs frequency measurement by applying ssb configuration information or smtc configuration information to the frequency to be measured based on the currently connected PCell.

[0237] Furthermore, the present invention proposes a second terminal operation in which frequency measurement is performed in different ways depending on which RRC message contains the frequency measurement configuration information set in the terminal.

[0238] When an RRC connected mode UE receives an RRC message, if the RRC message is an RRCRelease message, it transitions to an RRC inactive mode or an RRC idle mode, and if the RRC message includes frequency measurement configuration information (e.g., first frequency measurement configuration information for an RRC idle mode or an RRC inactive mode), the UE performs frequency measurement by applying the first, second, third, or fourth embodiment proposed in the present invention.

[0239] When an RRC connected mode UE receives an RRC message, if the RRC message is an RRC Reconfiguration message, it performs frequency measurement in the RRC connected mode. If the RRC message includes frequency measurement configuration information (e.g., first frequency measurement configuration information for the RRC connected mode), the UE performs frequency measurement by applying ssb configuration information or smtc configuration information to the frequency to be measured based on the currently connected PCell.

[0240] The RRC message includes the following pieces of information or parts thereof that are applied when the terminal performs fast frequency measurement in RRC idle mode, RRC inactive mode, or RRC connected mode:

[0241] -Frequency setting information measured in RRC idle mode or RRC inactive mode

[0242] ■ Frequency setting information

[0243] ◆LTE frequency measurement information group or list (EUTRA frequency configuration information / list / group)

[0244] ●Settings include frequency measurement configuration information (early measurement setup) such as which frequency or frequency band to measure (e.g., frequency list), which procedure to use for measurements by setting priorities for each frequency, which filtering method to use to measure the frequency strength when measuring the frequency (e.g., L1 filtering, L2 filtering, L3 filtering method, or which coefficients to use and which calculation method to use), which event or condition to start measurement according to when measuring the frequency, which criteria to use for measurement and reporting when compared with the current serving cell (or currently camped on frequency) (e.g., when the signal strength is above a threshold), which event or condition to use to report the measured frequency results, which criteria or conditions to use when compared with the current serving cell (or currently camped on frequency) to report the frequency, and at what interval to report the frequency measurement results.

[0245] NR frequency configuration information / list / group

[0246] ●Settings include frequency measurement configuration information (early measurement setup) such as which frequency or frequency band to measure (e.g., frequency list), or SSB identifier information or SSB transmission resources for each frequency (or SSB) to prioritize and the procedure for measurements, which filtering method to use to measure the frequency strength when measuring the frequency (e.g., L1 filtering, L2 filtering, L3 filtering method, or which coefficients to use and which calculation method to use), which event or condition to start measurement according to when measuring the frequency, which criteria to use for measurement and reporting when compared with the current serving cell (or currently camped on frequency) (e.g., when the signal strength is above a threshold), which event or condition to use to report the measured frequency results, which criteria or conditions to use when compared with the current serving cell (or currently camped on frequency) to report the frequency, and at what interval to report the frequency measurement results.

[0247] ■ RRC idle mode or RRC inactive mode frequency measurement period or frequency measurement timer value (e.g., T331): According to one embodiment, the same timer is set for the LTE frequency and the NR frequency, or a timer for the LTE frequency and a timer for the NR frequency are set separately. This is because the LTE frequency characteristics (low frequency band) and the NR frequency characteristics (high frequency band) are different, so the frequency measurement time of the terminal is adjusted separately to conserve the terminal battery. For example, if a frequency measurement is instructed in RRC idle mode or RRC inactive mode by RRCRelease, the timer is started and frequency measurement is performed while the timer is running, and frequency measurement is stopped when the timer expires.

[0248] ■Valid area information for frequency measurement in RRC idle mode or RRC inactive mode: For example, based on a list of physical cell identifiers (PCIDs), the UE performs frequency measurement when it is in a cell indicated by the area information, and suspends the frequency measurement when it is outside the area information. For example, when it is outside the area information, it stops a timer and suspends frequency measurement. Alternatively, for a UE transitioning to the RRC inactive mode, the base station may use an indicator to determine whether to use the RAN indication area as the valid area. For example, if the base station instructs a UE transitioning to the RRC inactive mode to use the RAN indication area as the valid area through an indicator, the UE performs frequency measurement within the RAN indication area while maintaining the RRC inactive mode within the RAN indication area. Alternatively, an indicator may be used to instruct the UE to use the valid area as the RAN indication area. Alternatively, in the RRC inactive mode, the UE may treat the RAN indication area as the valid area and apply it even without an indicator, and in the RRC active mode, a separate valid area may be configured for the UE. Since both the RAN indication area and the validity area are indicated in the cell identifier list in the RRC message, the signaling overhead can be reduced through the proposed method, and since the validity area does not need to be managed separately in the implementation of the terminal, the implementation burden on the terminal can be reduced.

[0249] ■ Measurement Report Threshold: Report one or more frequencies in the set frequency group that have a signal strength better than the threshold.

[0250] The conditions under which the UE stops fast frequency measurement in RRC idle mode or inactive mode are one or more of the following conditions.

[0251] 1. When the system information of the current cell supports early frequency measurement result reporting and transmits or is about to transmit a measurement result report to the base station in an RRC message (e.g., message 5)

[0252] 2. If the system information of the current cell does not indicate that early frequency measurement result reporting is supported

[0253] 3. When the terminal performs frequency measurement in RRC idle mode or RRC inactive mode, establishes a connection to the network, stops the timer when it receives an RRC Setup message or an RRC Resume message in message 4, stops the measurement, supports early frequency measurement result reporting in the system information of the current cell, and attempts to transmit a measurement result report to the base station in an RRC message (e.g., message 5).

[0254] 4. If a measurement report timer (e.g., T331) expires:

[0255] 5. If the RRC idle mode or RRC inactive mode frequency measurement area information set in the RRCRelease message is outside the area indicated by the

[0256] Depending on one or more of the above conditions, the terminal stops RRC idle mode or RRC inactive mode frequency measurement (IDLE mode / INACTIVE mode measurement).

[0257] The terminal performs measurements on frequencies that it can measure based on early frequency configuration related information, i.e., frequencies that its terminal capability (UE capability) supports (frequencies that allow CA or DC), and at this time the terminal can also select frequencies on which to perform measurements preferentially according to a predetermined set priority.

[0258] In another method, when region configuration information (configuration information for a region where frequency measurement configuration is valid) is configured in the UE in the configuration information for frequency measurement in RRC idle mode or RRC inactive mode in the RRCRelease message, the UE stops or restarts frequency measurement in RRC idle mode or RRC inactive mode while a timer indicating the frequency measurement period is driven (if the timer does not expire) based on the system information or cell identifier of the cell on which the UE is camped. Specifically, since the UE in RRC idle mode or RRC inactive mode is moving while performing a cell selection or reselection procedure, if the physical cell identity of the serving cell on which the UE is camped is included in the region configuration information, the UE continues to perform frequency measurement and continues to drive the timer indicating the frequency measurement period. However, since a UE in RRC idle mode or RRC inactive mode is moving while performing a cell selection or reselection procedure, if the physical cell identity of the serving cell on which it is camped is not included in the area configuration information, it stops frequency measurement, continues to run the timer indicating the frequency measurement period, and maintains the frequency measurement configuration information set in the RRC message (if the frequency measurement information (or frequency measurement list) is set in the RRC message). If the UE further reselects and camps on a cell having a cell identifier included in the area configuration information, it starts frequency measurement again while the timer is running (if the timer has not expired). Furthermore, the frequency measurement configuration information is released or discarded when the timer indicating the frequency measurement period expires.

[0259] -1> When the terminal receives an RRCRelease message (or receives an RRCRelease message in response to an RRCResumeRequest), the base station does not set frequency measurement configuration information in the RRCRelease message, or the terminal does not receive frequency measurement configuration (or frequency measurement list) in the RRCRelease message.

[0260] ■2> The terminal receives or acquires and stores frequency measurement configuration information for RRC idle mode or RRC inactive mode frequency measurement from the system information (e.g., SIB5) of the cell it is camped on. Then, it performs or restarts RRC idle mode or RRC inactive mode frequency measurement according to the frequency measurement configuration information. Alternatively, if the RRCRelease message does not contain frequency measurement configuration information, it can stop frequency measurement based on an instruction to stop frequency measurement, stop the timer, and discard the frequency configuration information or frequency measurement results. Alternatively, it can define and instruct an indicator to discard or maintain the frequency configuration information or frequency measurement results in the RRCRelease message.

[0261] -1> When the terminal receives an RRCRelease message (or receives an RRCRelease message in response to an RRCResumeRequest), if the base station sets frequency measurement configuration information in the RRCRelease message, or if the terminal receives frequency measurement configuration (or frequency measurement list) in the RRCRelease message, or if the frequency measurement timer is running (if the frequency measurement timer has not expired)

[0262] ■2> Discard the existing stored frequency measurement setting information or frequency measurement results. Alternatively, an indicator for discarding or maintaining the frequency setting information or frequency measurement results can be defined and instructed in the RRCRelease message, and only part of the stored frequency setting information can be added, changed, or deleted.

[0263] ■2> The frequency measurement setting information set in the RRCRelease message is stored or set, and frequency measurement in RRC idle mode or RRC inactive mode is performed or restarted according to the information.

[0264] -1> When the UE indicates that it supports RRC idle mode or RRC inactive mode frequency measurement in the system information of the camped-on cell, or when the timer for frequency measurement is running (when the timer for frequency measurement has not expired)

[0265] -1> Or, when the terminal caps on a cell having a frequency or cell identifier included in the region setting information for frequency measurement in RRC idle mode or RRC inactive mode (setting information set in an RRC message (e.g., RRCRelease)), or when the terminal caps on again, or when the timer for frequency measurement is running (when the timer for frequency measurement has not expired)

[0266] ■2> When the base station does not set frequency measurement setting information in the RRCRelease message, or when the terminal does not receive frequency measurement setting (or frequency measurement list) in the RRCRelease message

[0267] ◆3> The terminal receives or acquires and stores frequency measurement configuration information for RRC idle mode or RRC inactive mode frequency measurement from the system information (e.g., SIB5) of the cell it is camped on.

[0268] ◆3>Perform or restart RRC idle mode or RRC inactive mode frequency measurement according to frequency measurement configuration information.

[0269] ■2> When the base station sets frequency measurement setting information in the RRCRelease message, or when the terminal receives frequency measurement setting (or frequency measurement list) in the RRCRelease message, or when the timer for frequency measurement is running (when the timer for frequency measurement has not expired)

[0270] ◆3>Perform or restart RRC idle mode or RRC inactive mode frequency measurement according to the frequency measurement configuration information set in the RRCRelease message.

[0271] -1> If the UE does not indicate that it supports RRC idle mode or RRC inactive mode frequency measurement in the system information of the camped-on cell, or if the timer for frequency measurement is running (if the timer for frequency measurement has not expired)

[0272] -1> Or, when the terminal caps on a cell having a frequency or cell identifier not included in the area setting information for frequency measurement in RRC idle mode or RRC inactive mode (setting information set in the RRC message (e.g., RRCRelease)), or when the terminal caps on again, or when the timer for frequency measurement is running (when the timer for frequency measurement has not expired).

[0273] ■2> The terminal stops frequency measurements for RRC idle mode or RRC inactive mode.

[0274] ■2> (The timer that indicates the frequency measurement period is characterized by being continuously driven.)

[0275] FIG. 18 illustrates a terminal operation for performing RRC idle mode or RRC inactive mode frequency measurement and reporting the measurement result according to an embodiment of the present invention.

[0276] In Figure 18, when the UE receives an RRC message, it starts a timer for RRC idle mode or RRC inactive mode frequency measurement, receives frequency measurement configuration information for RRC idle mode or RRC inactive mode frequency measurement (if present in the RRC message) (18-05), or performs a cell selection or reselection procedure and receives frequency measurement information in the system information of the serving cell it is camped on (18-05), and performs RRC idle mode or RRC inactive mode frequency measurement (18-10). The UE performs frequency measurement according to the first, second, third, or fourth embodiment proposed in the present invention. When the UE performs frequency measurement, it stores the measurement result, and if there is an indicator supporting RRC idle mode or RRC inactive mode frequency measurement in the system information of the cell where it has established a connection with the network, it receives message 4 when establishing a connection with the network, stops the timer (18-15), and notifies the network of the presence of the RRC idle mode or RRC inactive mode frequency measurement result via message 5. Then, when the base station requests the RRC idle mode or RRC inactive mode frequency measurement result, the terminal reports the measurement result (18-20), and if the measurement result is successfully transmitted to the base station, the terminal discards the measurement result.

[0277] FIG. 19 is a diagram showing the configuration of a terminal according to an embodiment of the present invention.

[0278] Referring to the drawing, the terminal includes a radio frequency (RF) processor 1910, a baseband processor 1920, a memory 1930, and a controller 1940.

[0279] The RF processing unit 1910 performs functions for transmitting and receiving signals through a wireless channel, such as signal band conversion and amplification. That is, the RF processing unit 1910 up-converts a baseband signal provided from the baseband processing unit 1920 to an RF band signal and transmits the signal through an antenna, and down-converts an RF band signal received through an antenna to a baseband signal. For example, the RF processing unit 1910 includes 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 only one antenna is illustrated in the drawings, a terminal may have multiple antennas. The RF processing unit 1910 also includes multiple RF chains. The RF processing unit 1910 also performs beamforming. For beamforming, the RF processing unit 1910 adjusts the phase and magnitude of each signal transmitted and received through multiple antennas or antenna elements. The RF processing unit also performs MIMO and receives multiple layers when MIMO operations are performed. The RF processing unit 1910 performs receive beam sweeping by appropriately setting multiple antennas or antenna elements under the control of the control unit, or adjusts the direction and beam width of the receive beam so that the receive beam cooperates with the transmit beam.

[0280] Baseband processor 1920 performs conversion between a baseband signal and a bit stream according to the system's physical layer standard. For example, during data transmission, baseband processor 1920 generates complex symbols by encoding and modulating a transmission bit stream. During data reception, baseband processor 1920 restores a received bit stream by demodulating and decoding the baseband signal provided from RF processor 1910. For example, in the case of orthogonal frequency division multiplexing (OFDM), during data transmission, baseband processor 1920 generates complex symbols by encoding and modulating a transmission bit stream, maps the complex symbols to subcarriers, and then constructs OFDM symbols through inverse fast Fourier transform (IFFT) calculations and cyclic prefix (CP) insertion. In addition, when receiving data, the baseband processing unit 1920 divides the baseband signal provided from the RF processing unit 1910 into OFDM symbol units, restores the signal mapped to the subcarrier through an FFT (fast Fourier transform) operation, and then restores the received bit string through demodulation and decoding.

[0281] Baseband processor 1920 and RF processor 1910 transmit and receive signals as described above. Therefore, baseband processor 1920 and RF processor 1910 are referred to as a transmitter, receiver, transceiver, or communication unit. At least one of baseband processor 1920 and RF processor 1910 includes multiple communication modules to support multiple different wireless access technologies. At least one of baseband processor 1920 and RF processor 1910 includes different communication modules to process signals in different frequency bands. For example, the different wireless access technologies include an LTE network, an NR network, etc. The different frequency bands include a super high frequency (SHF) band (e.g., 2.5 GHz, 5 GHz) and a millimeter wave (mm wave) band (e.g., 60 GHz).

[0282] The storage unit 1930 stores data such as basic programs, applications, setting information, etc. for the operation of the terminal. The storage unit 1930 provides the stored data in response to a request from the control unit 1940.

[0283] The controller 1940 controls the overall operation of the terminal. For example, the controller 1940 transmits and receives signals via the baseband processor 1920 and the RF processor 1910. The controller 1940 also records data in and reads data from the memory 1940. To this end, the controller 1940 includes at least one processor. For example, the controller 1940 includes a communication processor (CP) that controls communications and an application processor (AP) that controls upper layers such as application programs.

[0284] FIG. 20 is a diagram showing a block configuration of a TRP in a wireless communication system according to one embodiment of the present invention.

[0285] As shown in the drawing, the base station includes an RF processing unit 2010, a baseband processing unit 2020, a backhaul communication unit 2030, a storage unit 2040, and a control unit 2050.

[0286] The RF processor 2010 performs functions such as signal band conversion and amplification to transmit and receive signals through a wireless channel. That is, the RF processor 2010 up-converts a baseband signal provided from the baseband processor 2020 to an RF band signal and transmits the up-converted signal via an antenna, and down-converts an RF band signal received via an antenna to a baseband signal. For example, the RF processor 2010 includes a transmit filter, a receive filter, an amplifier, a mixer, an oscillator, a DAC, an ADC, etc. Although only one antenna is illustrated in the drawings, the first access node has multiple antennas. The RF processor 2010 also includes multiple RF chains. The RF processor 2010 also performs beamforming. For beamforming, the RF processor 2010 adjusts the phase and magnitude of each signal transmitted and received via multiple antennas or antenna elements. The RF processor performs down-conversion MIMO operation by transmitting one or more layers.

[0287] The baseband processor 2020 performs conversion between a baseband signal and a bit stream in accordance with the physical layer standard of the first wireless access technology. For example, during data transmission, the baseband processor 2020 generates complex symbols by encoding and modulating a transmission bit stream. During data reception, the baseband processor 2020 demodulates and decodes the baseband signal provided by the RF processor 2010 to restore a received bit stream. For example, in the OFDM scheme, during data transmission, the baseband processor 2020 generates complex symbols by encoding and modulating a transmission bit stream, maps the complex symbols to subcarriers, and constructs OFDM symbols through IFFT and CP insertion. During data reception, the baseband processor 2020 divides the baseband signal provided by the RF processor 2010 into OFDM symbols, restores the signals mapped to the subcarriers through FFT, and restores the received bit stream through demodulation and decoding. The baseband processor 2020 and the RF processor 2010 transmit and receive signals as described above, and are therefore referred to as a transmitter, a receiver, a transceiver, a communication unit, or a wireless communication unit.

[0288] The communication unit 2030 provides an interface for communicating with other nodes in the network.

[0289] The memory unit 2040 stores data such as basic programs, applications, and setting information for the operation of the main base station. In particular, the memory unit 2040 stores information on bearers assigned to connected terminals, measurement results reported from connected terminals, etc. The memory unit 2040 also stores information that serves as a criterion for determining whether to provide or suspend multiple connections to terminals. The memory unit 2040 provides the stored data in response to a request from the control unit 2050.

[0290] The controller 2050 controls the overall operation of the primary base station. For example, the controller 2050 transmits and receives signals via the baseband processor 2020 and the RF processor 2010 or via the backhaul communication unit 2030. The controller 2050 also records and reads data in and from the memory unit 2040. To this end, the controller 2050 includes at least one processor.

[0291] Although the present invention has been described in exemplary embodiments, various changes and modifications will be suggested by those skilled in the art, and it is intended that the present invention encompass all such changes and modifications that fall within the scope of the appended claims. [Explanation of symbols]

[0292] 1-05, 1-10, 1-15, 1-20, 3-30 eNB(Evolved Node B) 1-25, 3-25 MME 1-30 S-GW 1-35 UE (terminal) 2-05, 2-40 PDCP (Packet Data Convergence Protocol) 2-10, 2-35 RLC (Radio Link Control) 2-15, 2-30 MAC (Medium Access Control) 2-20, 2-25 PHY (physical layer) 3-05 NR CN 3-10 NR gNB 3-15 NR UE 3-20 Radio access 4-01, 4-45 NR SDAP 4-05, 4-40 NR PDCP 4-10, 4-35 NR RLC 4-15, 4-30 NR MAC 4-20, 4-25 NR PHY 8-05, 9-05 BW (Bandwidth) 8-10 First LTE frequency (Freq1) 8-20 CRS (Channel Reference Signal) 9-01 First NR frequency (Freq1) 9-10, 9-20 Partial Bandwidth (BWP1, BWP2) 9-15 SSB1 9-25 SSB2 10-01, 10-05 SFN (System Frame Number) of PCell (or serving cell) 10-21 offset 10-22 cycles 10-23 Institution 11-01, 12-01 Cell1 11-02, 12-02 Cell 2 13-01~13-08 Frequency 1~Frequency 8 13-10, 14-10, 15-10, 16-10 First frequency setting information 13-20, 14-20, 15-20, 16-20 Second frequency setting information 14-01~14-08 Frequency 1~Frequency 8 15-01~15-08 Frequency 1~Frequency 8 1910, 2010 RF processing section 1920, 2020 Baseband processing section 1930, 2040 storage section 1940, 2050 Control Unit 1942, 2052 Multiple connection processing unit 2030 Backhaul Communications Department

Claims

1. 1. A method performed by a terminal in a communication system, comprising: receiving a radio resource control (RRC) release message including first measurement configuration information for a terminal in an RRC_IDLE state or an RRC_INACTIVE state; receiving a system information block (SIB) from a base station; If the first measurement configuration information includes a first frequency but does not include a synchronization signal block (SSB) configuration corresponding to the first frequency, identifying whether the SIB includes second measurement configuration information including the first frequency and a synchronization signal block (SSB) configuration corresponding to the first frequency; If the SIB includes second measurement configuration information including the first frequency and an SSB configuration corresponding to the first frequency, performing measurement on the first frequency based on the SSB configuration included in the second measurement configuration information while the terminal is in an RRC_IDLE state or an RRC_INACTIVE state and a timer is running, The method, wherein the SSB configuration includes information on a period, a duration, and an offset associated with the SSB.

2. If the RRC release message does not include a new radio (NR) frequency list and does not include a long term evolution (LTE) frequency list, the method further comprises: identifying third measurement configuration information included in the SIB, the third measurement configuration information including a second frequency and an SSB configuration corresponding to the second frequency; and performing measurements on the second frequency based on an SSB configuration corresponding to the second frequency while the terminal is in an RRC_IDLE state or an RRC_INACTIVE state and the timer is running.

3. the timer runs in response to receiving the RRC release message; The method of claim 1, wherein information regarding the timer period is included in the RRC release message.

4. 2. The method of claim 1, wherein the measurements are initiated based on cell selection in an RRC_IDLE or RRC_INACTIVE state.

5. A terminal in a communication system, a transmitter / receiver; a control unit, The control unit Receive a radio resource control (RRC) release message including first measurement configuration information for a terminal in an RRC_IDLE state or an RRC_INACTIVE state; receiving a system information block (SIB) from a base station; If the first measurement configuration information includes a first frequency but does not include a synchronization signal block (SSB) configuration corresponding to the first frequency, identifying whether the SIB includes second measurement configuration information including the first frequency and an SSB configuration corresponding to the first frequency; If the SIB includes second measurement configuration information including the first frequency and an SSB configuration corresponding to the first frequency, the terminal is configured to perform measurements on the first frequency based on the SSB configuration included in the second measurement configuration information while the terminal is in an RRC_IDLE state or an RRC_INACTIVE state and a timer is running; The terminal, wherein the SSB configuration includes information on a period, a duration, and an offset associated with the SSB.

6. If the RRC release message does not include a new radio (NR) frequency list and does not include a long term evolution (LTE) frequency list, the control unit: Identifying third measurement configuration information included in the SIB, the third measurement configuration information including a second frequency and an SSB configuration corresponding to the second frequency; The terminal of claim 5, wherein the terminal is configured to perform measurements on the second frequency based on an SSB configuration corresponding to the second frequency while the terminal is in an RRC_IDLE state or an RRC_INACTIVE state and the timer is running.

7. the timer runs in response to receiving the RRC release message; The terminal of claim 5, wherein information about the timer period is included in the RRC release message.

8. The terminal according to claim 5, wherein the measurement is initiated based on cell selection in an RRC_IDLE state or an RRC_INACTIVE state.

9. 1. A method performed by a base station in a communication system, comprising: generating a system information block (SIB) including measurement configuration information for a terminal in an RRC_IDLE state or an RRC_INACTIVE state; transmitting the SIB; the measurement setting information includes a first frequency and a synchronization signal block (SSB) setting corresponding to the first frequency; If the RRC (radio resource control) release message received by the terminal includes the first frequency but does not include an SSB configuration corresponding to the first frequency, the SSB configuration corresponding to the first frequency included in the SIB is used for measurement while the terminal is in an RRC_IDLE state or an RRC_INACTIVE state and a timer is running; The method, wherein the SSB configuration includes information on a period, a duration, and an offset associated with the SSB.

10. 10. The method of claim 9, wherein if the RRC release message does not include a new radio (NR) frequency list or a long term evolution (LTE) frequency list, and the SIB includes measurement configuration information including a second frequency and an SSB configuration corresponding to the second frequency, the SSB configuration corresponding to the second frequency included in the SIB is used for measurement while the terminal is in an RRC_IDLE state or an RRC_INACTIVE state and the timer is running.

11. the timer runs in response to receiving the RRC release message; The method of claim 9, wherein information regarding the timer period is included in the RRC release message.

12. 10. The method of claim 9, wherein the measurements are initiated based on cell selection in an RRC_IDLE or RRC_INACTIVE state.

13. A base station in a communication system, comprising: a transmitter / receiver; a control unit, The control unit Generate a system information block (SIB) including measurement configuration information for a terminal in an RRC_IDLE state or an RRC_INACTIVE state; configured to transmit the SIB; the measurement setting information includes a first frequency and a synchronization signal block (SSB) setting corresponding to the first frequency; If the RRC (radio resource control) release message received by the terminal includes the first frequency but does not include an SSB configuration corresponding to the first frequency, the SSB configuration corresponding to the first frequency included in the SIB is used for measurement while the terminal is in an RRC_IDLE state or an RRC_INACTIVE state and a timer is running; The base station, wherein the SSB configuration includes information on a period, a duration, and an offset associated with the SSB.

14. 14. The base station of claim 13, wherein if the RRC release message does not include a new radio (NR) frequency list or a long term evolution (LTE) frequency list, and the SIB includes measurement configuration information including a second frequency and an SSB configuration corresponding to the second frequency, the SSB configuration corresponding to the second frequency included in the SIB is used for measurement while the terminal is in an RRC_IDLE state or an RRC_INACTIVE state and the timer is running.

15. the timer runs in response to receiving the RRC release message; The base station of claim 13, wherein information about the timer period is included in the RRC release message.

16. The base station according to claim 13, wherein the measurement is initiated based on cell selection in an RRC_IDLE state or an RRC_INACTIVE state.

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