Method and apparatus for determining frequency measurement sequence according to base station configuration in next generation mobile communication system

Abstract

The present disclosure relates to a 5G or 6G communication system for supporting a higher data transmission rate. An apparatus and method for configuring a frequency measurement sequence in a wireless communication system are provided. A method performed by a base station includes transmitting, to a terminal, a radio resource control message including configuration information on at least one measurement to be performed by the terminal, the configuration information including first information on a measurement object and second information on a reporting configuration; and receiving, from the terminal, a measurement report including at least one measurement result based on the configuration information. The first information includes information indicating a measurement sequence of a corresponding one of the measurement objects.

Description

TECHNICAL FIELD

[0001] The disclosure relates generally to a wireless communication system, and more particularly, to a method and apparatus for configuring a frequency measurement sequence in a wireless communication system. BACKGROUND

[0002] The 5th-Generation (5G) mobile communication technologies define wide frequency bands so that high transmission rates and new services are possible, and are implemented not only in below 6 thousand Megahertz (GHz) bands such as 3.5 GHz, but also in above 6 GHz bands such as 28 GHz and 39 GHz, which are called millimeter wave (mmWave) bands. Also, it has been considered to implement 6th-Generation (6G) mobile communication technologies in terahertz (THz) bands of 95 GHz to 3 THz bands so as to achieve transmission rates fifty times faster than 5G mobile communication technologies and ultra-low latency of less than one thousandth of 5G mobile communication technologies.

[0003] In the initial stage of 5G mobile communication technologies, in order to support services and meet requirements related to performance, such as enhanced Mobile BroadBand (eMBB), Ultra-Reliable and Low Latency Communications (URLLC), and massive Machine-Communications (mMTC), standardization has been made on technologies such as beamforming and massive MIMO to mitigate radio wave path loss and increase radio wave transmission distance in mmWave, a dynamic operation supporting numerologies (for example, operating multiple subcarrier spacings) and slot formats for efficient utilization of mmWave resources, initial access techniques supporting multi-beam transmission and wideband, definition and operation of bandwidth parts (BWPs), new channel coding methods such as Low Density Parity Check (LDPC) codes for large data transmission and polar codes for highly reliable transmission of control information, Layer 2 (L2) pre-processing, and network slicing for providing a dedicated network dedicated to a specific service.

[0004] Currently, in view of services to be supported by 5G mobile communication technologies, discussions are underway on improvement and performance enhancement of initial 5G mobile communication technologies, and there has been ongoing standardization on physical layers such as Vehicle-to-Everything (V2X) for helping autonomous vehicles make driving decisions based on information about positions and states of vehicles transmitted by the vehicles and for enhancing user convenience, New Radio Unlicensed (NR-U) aiming system operation compliant with various regulatory requirements in unlicensed bands, NR User Equipment (UE) power saving, Non-Terrestrial Network (NTN) as UE-satellite direct communication for providing coverage in an area where communication with terrestrial networks is unavailable, and positioning.

[0005] Further, in the air interface architecture / protocol, standardization on technologies such as Industrial Internet of Things (IIoT) for support of new services through interworking and convergence with other industries, IAB (Integrated Access and Backhaul) for providing a node for network service area expansion by supporting a wireless backhaul link and an access link in an integrated manner, mobility enhancement including conditional handover and dual active protocol stack (DAPS) handover, and two-step random access (two-step RACH for NR) for simplifying a random access procedure, is in progress. In terms of system architecture / service, standardization is in progress on a 5G baseline architecture (e.g., service based architecture or service based interface) for combining Network Functions Virtualization (NFV) and Software-Defined Networking (SDN) technologies, and mobile edge computing (MEC) for receiving services based on UE location.

[0006] If such a 5G mobile communication system is commercialized, connected devices, which have been exponentially increasing, will be connected to the communication network, and thus it is expected that enhanced functionality and performance of the 5G mobile communication system and integrated operation of the connected devices will be necessary. To this end, new research related to extended reality (XR) for efficiently supporting augmented reality (AR), virtual reality (VR), mixed reality (MR), etc., improvement of 5G performance and reduction of 5G complexity by utilizing artificial intelligence (AI) and machine learning (ML), AI service support, metaverse service support, and drone communication is planned.

[0007] Such development of 5G mobile communication systems will serve as a basis for not only developing new waveforms for providing coverage in the THz band of 6G mobile communication technology, multi-antenna transmission technologies such as full dimensional MIMO (FD-MIMO), array antennas, and massive antennas, metamaterial-based lenses and antennas for improving coverage of THz band signals, high-dimensional spatial multiplexing technology using orbital angular momentum (OAM), and reconfigurable intelligent surfaces (RISs), but also developing full-duplex technologies for improving frequency efficiency of 6G mobile communication technology and ameliorating system networks, AI-based communication technologies for implementing system optimization by utilizing satellites and AI from the design stage and internalizing end-to-end AI support functions, and next-generation distributed computing technologies for implementing services by utilizing super-high-performance communication and computing resources at a level of complexity that exceeds the limitations of UE operating capabilities. SUMMARY

[0008] TECHNICAL PROBLEM

[0009] A base station configures a terminal with frequencies to be measured in order to properly serve the terminal, and the terminal performs a measurement operation on the configured frequencies and then provides information about the results to the base station. The base station can consider a cell that serves the terminal based on the measurement results from the terminal, and can perform a configuration such as handover of the terminal to the cell or addition of a connection of the terminal to the cell. Generally, the terminal measures the frequencies configured by the base station in a random sequence, resulting in a deficiency in optimization of frequencies that support a particular service.

[0010] Therefore, there is a need in the art for a method and apparatus by which measurement results of specific frequencies are preferentially reported according to a configuration to optimally provide a service used by a terminal.

[0011] Problem to be Solved

[0012] The present disclosure has been made to solve at least the above problems and / or disadvantages and to provide at least the advantages described below.

[0013] According to an aspect of the present disclosure, a method performed by a base station in a wireless communication system includes transmitting, to a terminal, a radio resource control message including configuration information about at least one measurement to be performed by the terminal, the configuration information including first information about a measurement object and second information about a reporting configuration, and receiving, from the terminal, a measurement report including at least one measurement result based on the configuration information, wherein the first information includes information indicating a measurement sequence of a corresponding measurement object among the measurement objects.

[0014] According to an aspect of the present disclosure, a method performed by a terminal in a wireless communication system includes receiving, from a base station, a radio resource control message including configuration information about at least one measurement to be performed by the terminal, the configuration information including first information about a measurement object and second information about a reporting configuration, and transmitting, to the base station, a measurement report including at least one measurement result based on the configuration information, wherein the first information includes information indicating a measurement sequence of a corresponding measurement object among the measurement objects.

[0015] According to an aspect of the present disclosure, a base station in a wireless communication system includes a transceiver and a controller configured to control the transceiver to transmit, to a terminal, a radio resource control message including configuration information about at least one measurement to be performed by the terminal, the configuration information including first information about a measurement object and second information about a reporting configuration, and to receive, from the terminal, a measurement report including at least one measurement result based on the configuration information, wherein the first information includes information indicating a measurement sequence of a corresponding measurement object among the measurement objects.

[0016] According to an aspect of the disclosure, a terminal in a wireless communication system includes a transceiver and a controller configured to control the transceiver to receive, from a base station, a radio resource control message including configuration information about at least one measurement to be performed by the terminal, the configuration information including first information about a measurement object and second information about a reporting configuration, and control the transceiver to transmit, to the base station, a measurement report including at least one measurement result based on the configuration information, wherein the first information includes information indicating a measurement sequence of a corresponding measurement object among the measurement objects.

[0017] Advantageous Effects

[0018] Accordingly, an aspect of the disclosure is to provide a method and apparatus for configuring a measurement sequence together when configuring a frequency to be measured for a terminal. BRIEF DESCRIPTION OF DRAWINGS

[0019] The above and other aspects, features and advantages of certain embodiments of the disclosure will be more apparent from the following description taken in conjunction with the accompanying drawings, in which:

[0020] Figure 1 A structure of a Long Term Evolution (LTE) system according to an embodiment is illustrated;

[0021] Figure 2 A radio protocol structure of an LTE system according to an embodiment is illustrated;

[0022] Figure 3 A structure of a next-generation mobile communication system according to an embodiment is illustrated;

[0023] Figure 4 A radio protocol structure of a next-generation mobile communication system according to an embodiment is illustrated;

[0024] Figure 5 A procedure in which a terminal transmits a measurement result message to a base station in a next-generation mobile communication system according to an embodiment is illustrated;

[0025] Figure 6 A procedure in which a terminal transmits a measurement result message to a base station in a next-generation mobile communication system according to an embodiment is illustrated;

[0026] Figure 7 A procedure in which a terminal transmits a measurement result message to a base station in a next-generation mobile communication system according to an embodiment is illustrated;

[0027] Figure 8 A procedure in which a terminal transmits a measurement result message to a base station in a next-generation mobile communication system according to an embodiment is illustrated;

[0028] Figure 9A process in which a terminal transmits a measurement result message to a base station in a next-generation mobile communication system according to an embodiment is shown.

[0029] Figure 10 An internal structure of a terminal according to an embodiment is shown; and

[0030] Figure 11 A configuration of an NR base station according to an embodiment is shown. DETAILED DESCRIPTION

[0031] The following description with reference to the accompanying drawings is provided to assist in a comprehensive understanding of embodiments of the present disclosure, and thus the present disclosure can be implemented in various ways. It will be immediately appreciated by those skilled in the art that various changes and modifications can be made to the embodiments described herein without departing from the scope and spirit of the present disclosure. Descriptions of well-known functions and configurations incorporated herein can be omitted for clarity and conciseness.

[0032] In the description, terms for identifying access nodes and referring to network entities, messages, interfaces between network entities, and identification information are used illustratively. Accordingly, the present disclosure is not limited by the terms used below, and other terms referring to a subject matter having equivalent technical meanings can be used.

[0033] Further, terms and names defined in the 3rd Generation Partnership Project LTE (3GPP LTE) standard will be used for convenience of description. However, the present disclosure is not limited by these terms and names, and can be similarly applied to systems conforming to other standards. For convenience of description, the term eNB can be used interchangeably with the term gNB. That is, a base station described as an eNB can indicate a gNB.

[0034] Figure 1 A structure of an LTE system according to an embodiment is shown.

[0035] Reference Figure 1 The radio access network of the LTE system includes next-generation base stations (evolved node Bs (eNBs), node Bs, or gNBs) 105, 110, 115, and 120, a mobility management entity (MME) 125, and a serving gateway (S-GW) 130. A UE (or terminal) 135 accesses an external network through the eNBs 105 to 120 and the S-GW 130.

[0036] In Figure 1In the LTE system, each of eNBs 105 to 120 corresponds to a conventional Node B in the Universal Mobile Telecommunications Service (UMTS) system. The eNB is connected to the UE 135 via a radio channel and performs a more complex role than a traditional Node B. In the LTE system, because all user services, including real-time services such as Voice over IP (VoIP) via the Internet Protocol, are served through shared channels, there is a need for equipment to collect state information such as buffer status, available transmit power status, and the UE's channel state and perform scheduling accordingly; eNBs 105 to 120 serve as this equipment. Typically, one eNB controls multiple cells. For example, to achieve a transmission rate of 100 megabits per second (Mbps), the LTE system uses Orthogonal Frequency Division Multiplexing (OFDM) as the radio access technology in a bandwidth of, for example, 20 MHz. The LTE system employs an Adaptive Modulation & Coding (AMC) scheme to determine the modulation scheme and channel coding rate based on the UE's channel state.

[0037] The S-GW 130 provides data bearers and generates or removes data bearers under the control of the MME 125.

[0038] The MME is responsible for various control functions and mobility management functions for the UE, and is connected to multiple base stations.

[0039] Figure 2 The radio protocol structure of an LTE system according to an embodiment is shown.

[0040] refer to Figure 2 The radio protocols of the LTE system include Packet Data Convergence Protocol (PDCP) 205 or 240, Radio Link Control (RLC) 210 or 235, and Media Access Control (MAC) 215 or 230 in each of the UE and ENB. PDCP 205 or 240 is used to perform operations such as IP header compression / reconstruction. The main functions of PDCP are robust header compression (ROHC) and decompression, transmission of user data, order delivery of upper-layer protocol data cells (PDUs) during PDCP reconstruction in Radio Link Control Acknowledgment Mode (RLC AM), support for split bearers in dual connectivity (DC) for routing RLC AM and PDCP PDUs for transmission and reordering PDCP PDUs for reception, duplicate detection of lower-layer serving data cells (SDUs) during PDCP reconstruction in RLC AM, retransmission of PDCP SDUs during handover, encryption and decryption of PDCP PDUs during PDCP data recovery in DC for split bearers, and timer-based SDU discarding in the uplink.

[0041] The Radio Link Control (RLC) 210 or 235 reconfigures PDCP protocol data cells (PDUs) to an appropriate size to perform Automatic Repeat Request (ARQ) operations. The main functions of the RLC are: transmission of upper-layer PDUs; error correction for AM data transmission via ARQ; concatenation, segmentation, and reassembly of RLC SDUs for Unacknowledged Mode (UM) and AM data transmissions; resegmentation of RLC data PDUs for AM data transmissions; reordering of RLC data PDUs for UM and AM data transmissions; duplicate detection for UM and AM data transmissions; protocol error detection for AM data transmissions; dropping RLC SDUs for UM and AM data transmissions; and RLC reconstruction.

[0042] MAC215 or 230 is connected to multiple RLC layer devices configured in a single UE, and multiplexes RLC PDUs to MAC PDUs and demultiplexes MAC PDUs to RLC PDUs. The main functions of MAC are mapping between logical channels and transport channels, multiplexing / demultiplexing MAC SDUs belonging to one or different logical channels into transport blocks (TBs) delivered to / from the physical layer on the transport channel, scheduling information reporting, error correction via Hybrid ARQ (HARQ), priority handling between logical channels of a UE, priority handling between UEs via dynamic scheduling, Multimedia Broadcast Multicast Service (MBMS) identification, transport format selection, and padding.

[0043] Physical layer 220 or 225 performs the following operations: channel coding and modulation of upper layer data to generate OFDM symbols and transmit them via a wireless channel, or demodulation of OFDM symbols received via a wireless channel, channel decoding of them, and delivery to the upper layer.

[0044] Figure 3 The structure of a next-generation mobile communication system according to an embodiment is shown.

[0045] Reference Figure 3 The radio access network for NR or 5G systems includes an NR gNB or NR base station 310 and a new radio core network (NR CN) 305. NR UEs or NR terminals 315 access external networks via the NR gNB 310 and NR CN 305.

[0046] exist Figure 3In this context, the NR gNB 310 corresponds to the ENB in ​​a traditional LTE system. The NR gNB 310 is connected to the NR UE 315 via a radio channel and can provide superior service compared to a traditional Node B. In next-generation mobile communication systems, since all user services are served through a shared channel, a device is needed to collect state information such as buffer status, available transmit power status, and the UE's channel state and perform scheduling accordingly. The NR gNB 310 serves as this device. One NR gNB typically controls multiple cells. To achieve ultra-high-speed data transmission beyond current LTE, next-generation mobile communication systems can provide bandwidths wider than the current maximum bandwidth, employing OFDM as the radio access technology and potentially integrating beamforming technology. Next-generation mobile communication systems employ an adaptive modulation and coding (AMC) scheme to determine the modulation scheme and channel coding rate based on the UE's channel state.

[0047] The NR CN 305 performs functions such as mobility support, bearer configuration, and quality of service (QoS) configuration. The NR CN is responsible for various control functions and mobility management functions for the UE, and is connected to multiple base stations. The next-generation mobile communication system can interoperate with existing LTE systems, and the NR CN is connected to the MME 325 via a network interface. The MME is connected to the eNB 330, which acts as a legacy base station.

[0048] Figure 4 The radio protocol structure of a next-generation mobile communication system according to an embodiment is shown.

[0049] refer to Figure 4 The radio protocols of the next-generation mobile communication system include NR Service Data Adaptation Protocol (SDAP) 401 or 445, NR PDCP 405 or 440, NR RLC 410 or 435 and NR MAC 415 or 430 in each of the UE and NR base stations.

[0050] The main functions of NR SDAP 401 or 445 may include the transmission of user plane data, mapping between QoS flows and data radio bearers (DRBs) for both DL and UL, marking QoS flow identifiers (IDs) in both DL and UL packets, and mapping reflected QoS flows from ULSDAP PDUs to DRBs.

[0051] Regarding SDAP layer devices, a UE can be configured to use the SDAP layer device header via RRC messages, or to use the SDAP layer device functionality for each PDCP layer device, each bearer, or each logical channel. If the SDAP header is configured, it can indicate the Non-Access Stratum (NAS) QoS Reflection Configuration 1-bit Indicator (NAS Reflected QoS) and Access Stratum (AS) QoS Reflection Configuration 1-bit Indicator (AS Reflected QoS), allowing the UE to update or reconfigure the mapping information for uplink and downlink QoS flows and data bearers. The SDAP header can include QoS flow ID information indicating QoS. QoS information can be used as data processing priority and scheduling information to smoothly support service.

[0052] The main functions of NR PDCP 405 or 440 may include ROHC and decompression, user data transmission, in-order delivery of upper-layer PDUs, out-of-order delivery of upper-layer PDUs, PDCP PDU reordering for reception, duplicate detection of lower-layer SDUs, retransmission of PDCPSDUs, encryption and decryption, and timer-based SDU discarding in the uplink.

[0053] Reordering of NR PDCP devices refers to reordering PDCP PDUs received from the lower layer in order based on the PDCP sequence number (SN), and may include functions such as transmitting data to the upper layer according to the reordered order, transmitting data directly without regard to the order, reordering to record lost PDCP PDUs, reporting the status of lost PDCP PDUs to the transmission side, or requesting retransmission of lost PDCP PDUs.

[0054] The main functions of NR RLC 410 or 435 may include the transmission of upper-layer PDUs, the in-order transmission of upper-layer PDUs, the out-of-order transmission of upper-layer PDUs, error correction via ARQ, the concatenation, segmentation and reassembly of RLC SDUs, the re-segmentation of RLC data PDUs, the reordering of RLC data PDUs, duplicate detection, protocol error detection, RLC SDU discarding, and RLC reconstruction.

[0055] In-order delivery of NR RLC devices refers to the sequential transmission of RLC SDUs received from the lower layer to the upper layer, and may include the following functions: if an original RLC SDU is divided into several RLC SDUs and then the RLC SDUs are received, the multiple RLC SDUs are reassembled and the reassembled RLC SDUs are transmitted; the received RLC PDUs are rearranged with reference to the RLC SN or PDCP SN; the order is rearranged to record lost RLC PDUs; the status of lost RLC PDUs is reported to the transmission side; the lost RLC PDUs are requested to be retransmitted; and the transmission is sequential. If there are lost RLC SDUs, only the RLC SDUs preceding the lost RLC SDU are transmitted to the upper layer. Even if there are lost RLC SDUs, if a predetermined timer has expired, all RLC SDUs received before the start of the timer are transmitted sequentially to the upper layer. Alternatively, even if there are lost RLC SDUs, if a predetermined timer has expired, all RLC SDUs received up to the present are transmitted sequentially to the upper layer.

[0056] RLC PDUs can be processed in the order they are received, regardless of sequence number or arrival order, and delivered to the PDCP device, regardless of the order. Segments stored in a buffer or to be received later can be received, reconfigured into a complete RLC PDU, processed, and delivered to the PDCP device. The NR RLC layer may not include concatenation functionality; concatenation functionality can be implemented in the NR MAC layer or replaced by multiplexing functionality in the NR MAC layer.

[0057] The out-of-order delivery function of NR RLC devices refers to the immediate delivery of RLC SDUs received from the lower layer to the upper layer, regardless of the order. It may include reassembling and delivering multiple received RLC SDUs, where one of the original RLCSDUs has been segmented, storing the RLC SN or PDCP SN of the received RLC PDUs, and recording RLC PDUs lost due to reordering.

[0058] NR MAC 415 or 430 can be connected to multiple NR RLC layer devices configured in a single UE, and the main functions of NR MAC can include mapping between logical channels and transport channels, multiplexing / demultiplexing of MAC SDUs, scheduling information reporting, error correction via HARQ, priority handling between logical channels of a UE, priority handling between dynamically scheduled UEs, MBMS service identification, transport format selection and padding.

[0059] The NR PHY layer 420 or 425 can perform the following operations: channel coding and modulation of upper-layer data to obtain OFDM symbols and deliver the symbols via radio channels, or demodulate OFDM symbols received via radio channels, channel decode the symbols and deliver them to the upper layer.

[0060] Figure 5 The process of a terminal sending a measurement result message to a base station in a next-generation mobile communication system according to an embodiment is illustrated.

[0061] When measuring frequencies configured by the base station, the terminal measures the frequency according to its own implementation, regardless of the base station's intent. This can lead to a situation where, even when a scheduled service such as Voice over LTE (VoLTE) is optimally available at a specific frequency, the service is provided to the terminal at a frequency other than the optimal frequency. Specifically, when the base station determines the frequency to provide service to the terminal, it uses the measurement result message sent by the terminal.

[0062] More specifically, when the base station receives a measurement result message from the terminal, it sends a predetermined handover message or an RRC connection release message containing RedirectedCarrierInfo indicating movement to a specific frequency to the terminal based on the received message. The terminal then moves to the specific target cell according to the base station's RRC configuration. When the base station provides VoLTE service to two terminals, it configures the same measurement configuration information (E-Universal Terral Radio Access (UTRA) frequency x, E-UTRA frequency y, and E-UTRA frequency z) for both terminals. The first terminal can first measure E-UTRA frequency x and then send a measurement result message based on frequency x to the base station. The second terminal can first measure E-UTRA frequency z and then send a measurement result message based on frequency z to the base station. Even when E-UTRA frequency x is optimized to provide VoLTE service, the base station can, based on the measurement result messages from both terminals, instruct only the first terminal to move to the cell belonging to E-UTRA frequency x and instruct the second terminal to move to the cell belonging to E-UTRA frequency z.

[0063] refer to Figure 5 In steps 505 and 506, the corresponding terminals 501 and 503 can establish an RRC connection with the NR base station 502 to be in RRC connection mode (RRC_CONNECTED).

[0064] In steps 510 and 511, base station 502 may send an RRC message (e.g., RRCReconfiguration) including measurement configuration information (MeasConfig) to each terminal 501 or 503. The measurement configuration information may include at least one of measurement object, report configuration, measurement identifier, measurement filter configuration information (quantity configuration), and measurement gap configuration information (measurement gap), and the description of each parameter described above is defined in Table 1 below.

[0065] Table 1

[0066]

[0067] Base station 502 can provide measurement configuration information for measuring frequencies within the specific cell (SpCell) corresponding to each terminal 501 or 503, frequencies adjacent to the SpCell, and frequencies using a different Radio Access Technology (RAT) than the SpCell. Specific information fields of this measurement configuration information may have the ASN.1 structure shown in Table 2 below.

[0068] Table 2

[0069]

[0070]

[0071] For simplicity, it is assumed here that base station 502 configures three frequencies for each terminal 501 and 503 using the same measurement configuration information: E-UTRA carrier frequency x, E-UTRA carrier frequency y, and E-UTRA carrier frequency z. These three frequencies are sequentially included in MeasObjectToAddModList or MeasIdToAddModList to provide the same measurement configuration information. For example, each MeasObjectToAddMod included in MeasObjectToAddModList can be configured as a MeasObject by measObjectId and MeasObjectUTRA (i.e., one of E-UTRA carrier frequency x, E-UTRA carrier frequency y, and E-UTRA carrier frequency z), and MeasObjectToAddModList can sequentially include (measObjectId 1, E-UTRA carrier frequency x), (measObjectId 2, E-UTRA carrier frequency y), and (measObjectId 3, E-UTRA carrier frequency z). For example, each MeasIdToAddMod included in MeasIdToAddModList is configured by measId, measObjectId, and reportConfigId, and MeasIdToAddModList may sequentially include (measId 1, measObjectID 1, reportConfigId 1), (measId 2, measObjectID 2, reportConfigID 2), and (measId 3, measObjectID 3, reportConfigID 3).

[0072] Each terminal 501, 503 may also perform measurements based on the measurement configuration information received from base station 502 in steps 515, 516. The order in which each terminal 501 or 503 measures the configured frequencies according to this disclosure may vary depending on the implementation of each terminal. For example, in step 515, terminal 501 (hereinafter referred to as the first terminal) may perform measurements in the order of the measObjects included in the MeasObjectToAddModList configured in MeasConfig (i.e., the order of e-UTRA frequency x, e-UTRA frequency y, and EUTRA frequency z). In step 516, terminal 503 (hereinafter referred to as the second terminal) may perform measurements in the reverse order of the measObjects included in the MeasObjectToAddModList configured in MeasConfig (i.e., the order of e-UTRA frequency x, e-UTRA frequency y, and EUTRA frequency z). Each terminal 501 or 503 can perform measurements by applying the measurement gap configuration information (measGapConfig) received in the measurement configuration information, or it can perform measurements without measurement gap configuration information (e.g., when interFrequencyConfig-NoGap is configured and the inter-frequency synchronization signal block (SSB) belongs to the active downlink bandwidth portion of the terminal). Each terminal 501 or 503 can perform measurement operations through the procedures described in Table 3 below.

[0073] Table 3

[0074]

[0075]

[0076]

[0077]

[0078]

[0079] When each terminal performs measurements through the above process, the method for performing layer 3 filtering (layer 3 filtering) can follow the process described in Table 4 below, the method for deriving cell measurement results (deriving cell measurement results) can follow the process described in Table 5 below, and the method for deriving layer 3 beam filtering measurement results (deriving layer 3 beam filtering measurement) can follow the process described in Table 6 below.

[0080] Table 4

[0081]

[0082] Table 5

[0083]

[0084]

[0085] Table 6

[0086]

[0087] In step 520, the first terminal 501 can determine whether the conditions for reporting a measurement result message (MeasurementReport) to the base station 502 are met based on the measurement results in step 515, i.e., whether a report has been triggered. Similarly, in step 521, the second terminal 503 can determine whether the conditions for reporting a measurement result message (MeasurementReport) to the base station 502 have been triggered based on the measurement results in step 516.

[0088] The conditions for triggering a measurement report, determined by each terminal 501 or 503, can be event-based or periodic. For example, the measurement configuration information sent in step 510 or 511 includes one or more measObjectIds, reportConfigIds, and measId, and each measId is mapped to a specific measObject and a specific reportConfig. Therefore, each terminal 501, 503 determines whether the reporting conditions (criteria) specified in the specific reportConfig are met. If the conditions are met, it can send a measurement result report message (MeasurementReport) to base station 502, containing the measId mapped to the reportConfig and the measurement result associated with that measId. More specifically, the process for determining whether each terminal 501 or 503 is triggered to report measurement results is defined in Table 7 below.

[0089] Table 7

[0090]

[0091]

[0092]

[0093]

[0094]

[0095]

[0096]

[0097]

[0098] In the following sections, each table will describe the events related to determining whether a measurement report is triggered.

[0099] Table 8 below relates to event A1.

[0100] Table 8

[0101]

[0102] Table 9 below relates to event A2.

[0103] Table 9

[0104]

[0105] Table 10 below relates to event A3.

[0106] Table 10

[0107]

[0108] Table 11 below relates to event A4.

[0109] Table 11

[0110]

[0111] Table 12 below relates to event A5.

[0112] Table 12

[0113]

[0114] Table 13 below relates to event A6.

[0115] Table 13

[0116]

[0117] Table 14 below relates to event B1.

[0118] Table 14

[0119]

[0120] Table 15 below relates to event B2.

[0121] Table 15

[0122]

[0123] Table 16 below relates to event I1.

[0124] Table 16

[0125]

[0126] Table 17 below relates to event C1.

[0127] Table 17

[0128]

[0129] Table 18 below relates to event C2.

[0130] Table 18

[0131]

[0132] Table 19 below relates to event D1.

[0133] Table 19

[0134]

[0135] Table 20 below relates to CondEvent T1.

[0136] Table 20

[0137]

[0138] Table 21 below relates to event X1.

[0139] Table 21

[0140]

[0141] Table 22 below relates to event X2.

[0142] Table 22

[0143]

[0144] Table 23 below relates to event Y1.

[0145] Table 23

[0146]

[0147] Table 24 below relates to event Y2.

[0148] Table 24

[0149]

[0150] refer to Figure 5 In step 525, the first terminal 501 may include the measurement results (measResults) for measId and the measurement reporting process that was triggered in step 520 in the measurement result message (MeasurementReport), and send the MeasurementReport to the base station 502. More specifically, the first terminal 501 may first measure the E-UTRA carrier frequency x and identify the measId associated with measObjectId=1 corresponding to the E-UTRA carrier frequency x (i.e., measId=1). If it is identified that the measurement reporting process has been triggered based on the measurement reporting condition (reportConfigId=1) mapped to the measId, the first terminal 501 may send the measurement results for measId to the base station 502. In step 526, the second terminal 503 may include the measurement results (measResults) for measId in the measurement result message (MeasurementReport) and send the measResults to the base station 502, the measurement reporting process for which the measResults was triggered in step 521. Unlike the first terminal 501, since the E-UTRA carrier frequency z is measured first, the measurement reporting process of the second terminal 503 may have already been triggered based on the measId (i.e., measId=3) associated with measObjectId=3 corresponding to the E-UTRA carrier frequency z and the measurement reporting condition (reportConfigId=3) mapped to it. The method by which each terminal 501 or 503 receives beam measurement information and cell measurement results from the measurement results can be the same as defined in Table 25 below.

[0151] Table 25

[0152]

[0153]

[0154] The detailed process by which each terminal 501 or 503 includes the measurement results (MeasResults) in the measurement report message can be shown in Table 26 below.

[0155] Table 26

[0156]

[0157]

[0158]

[0159]

[0160]

[0161]

[0162]

[0163]

[0164]

[0165] exist Figure 5 In this process, base station 502 can send a predetermined RRC message (e.g., MobilityFromNRCommand or an RRC connection release message containing a redirection CarrierInfo indicating a move to a specific frequency) to each terminal 501 or 503 based on the measurement result message received from each terminal 501 or 503 in steps 530 and 531, so as to move each terminal 501 or 503 to a specific inter-RAT target cell. For example, base station 502 can instruct the first terminal 501 to move to the target cell belonging to E-UTRA carrier frequency x in step 530, and instruct the second terminal 503 to move to the target cell belonging to E-UTRA carrier frequency z in step 531.

[0166] Figure 6 This illustrates the process by which a terminal sends a measurement result message to a base station in a next-generation mobile communication system according to an embodiment.

[0167] As described above, when measuring frequencies configured by a base station, a terminal can first measure a specific frequency based on the base station's configuration. If VoLTE is optimally provided at the specific frequency, the base station can configure the terminal to first measure the optimal frequency so as to provide service to the terminal at the optimal frequency. This is done by the base station providing the terminal with an RRC connection release message including a predetermined handover message or a redirection CarrierInfo indicating movement to the specific frequency, to redirect the terminal to a specific target cell based on the measurement result message sent by the terminal, as described above. For example, when E-UTRA frequency x is a frequency optimized for VoLTE service, when the base station provides measurement configuration information (E-UTRA frequency x, E-UTRA frequency y, and E-UTRA frequency z) to a terminal to which it intends to provide VoLTE service, the base station can configure the terminal to first measure E-UTRA frequency x and send a measurement result message based thereon to the base station, thereby moving the terminal to a cell belonging to E-UTRA frequency x.

[0168] refer to Figure 6 In step 605, terminal 601 can establish an RRC connection with NR base station 602 to be in RRC connection mode (RRC_CONNECTED).

[0169] In step 610, terminal 601 may send a UECapabilityInformation message to base station 602. For example, such a UECapabilityInformation message may be sent based on a UECapabilityEnquiry request from base station 602. The UECapabilityInformation message may include capability information (new capability bits to support intra-RAT / inter-RAT / inter-RAT frequency measurements according to the frequency sequence listed in MeasConfig) indicating that terminal 601 is capable of performing measurements corresponding to sequences of measObjects included in the measurement configuration information configured by base station 602. For example, the capability information may indicate the terminal's measurement capabilities corresponding to sequences of measObjects included in MeasObjectToAddModList. Alternatively, the capability information may indicate the terminal's measurement capabilities corresponding to sequences of MeasIDs included in MeasIdToAddModList.

[0170] In step 615, base station 602 may send a predetermined RRC message (e.g., RRCReconfiguration) including measurement configuration information (MeasConfig) to terminal 601. Here, the accompanying drawings illustrate the process by which the base station provides the terminal's measurement configuration information after receiving the terminal's capability information message; however, the process of receiving the capability information message from the terminal may be omitted.

[0171] When a capability information message is received from terminal 601, base station 602 can provide measurement configuration information to terminal 601 based on the capability information message. Additionally, multiple pieces of information contained in the measurement configuration information (MeasConfig) can also be combined with the above... Figure 5 The information provided continues.

[0172] For simplicity, the description describes the case where base station 602 configures three frequencies for terminal 601 using measurement configuration information, namely E-UTRA carrier frequency x, E-UTRA carrier frequency y, and E-UTRA carrier frequency z, and sequentially includes the three frequencies in MeasObjectToAddModList or MeasIdToAddModList, but this disclosure is not limited thereto. Each MeasObjectToAddMod included in MeasObjectToAddModList is configured by measObjectId and MeasObject. MeasObjectEUTRA (i.e., one of E-UTRA carrier frequency x, E-UTRA carrier frequency y, and E-UTRA carrier frequency z) can be configured as MeasObject, and MeasObjectToAddModList can sequentially include (measObjectId x, E-UTRA carrier frequency x), (measObjectId y, E-UTRA carrier frequency y), and (measObjectId z, E-UTRA carrier frequency z). For example, each MeasIdToAddMod included in MeasIdToAddModList is configured by measId, measObjectId, and reportConfigId, and MeasIdToAddModList can sequentially include (measId x, measObjectId x, reportConfigId x), (measId y, measObjectId y, reportConfigId y), and (measId z, measObjectId z, reportConfigId z). When configuring measurement configuration information for a terminal, the base station can include and provide an indicator in the measurement configuration information that indicates sequential frequency measurements corresponding to the information present in MeasObjectToAddModList or MeasIdToAddModList. The terminal can sequentially measure E-UTRA carrier frequency x, E-UTRA carrier frequency y, and E-UTRA carrier frequency z according to the indicator.

[0173] In step 620, terminal 601 can perform measurements based on the measurement configuration information received from base station 602. Terminal 601 can measure the configured frequency according to the sequence of measObjects (i.e., the sequence of E-UTRA frequency x, E-UTRA frequency y, and E-UTRA frequency z) included in MeasObjectToAddModList configured in MeasConfig. Terminal 601 can perform measurements according to the sequence of measId included in measIdToAddModList(measId x, measObjectId x (i.e., E-UTRA frequency x), reportConfigId 1), (measId y, measObjectId y (i.e., E-UTRA frequency y), reportConfigId 2) and (measId z, measObjectId z (i.e., E-UTRA frequency z), reportConfigId z)). Specific measurement methods can process the above information.

[0174] In step 625, terminal 601 can determine, based on the measurement results from step 620, whether the conditions for reporting a measurement result message (MeasurementReport) to base station 602 have been triggered. Similarly, this determination can continue with the information described above.

[0175] In step 625, when terminal 601 determines that the conditions for reporting the measurement result message have been triggered, in step 630, terminal 601 can include the measurement results (measResults) for the measId that its measurement reporting process has been triggered in the measurement result message (MeasurementReport) and send it to base station 602. Therefore, terminal 601 can first measure the E-UTRA carrier frequency x and trigger the measurement reporting process based on its associated measId (i.e., measId=x, measObjectId=x, reportConfigId=x). The detailed process of terminal 601 including the measurement results (MeasResults) in the measurement report message can be further explained above.

[0176] In step 635, base station 602 may send a predetermined RRC message (e.g., MobilityFromNRCommand or an RRC connection release message including a redirection CarrierInfo indicating movement to a specific frequency) to terminal 601 based on the measurement result message received from terminal 601, thereby redirecting terminal 601 to a specific inter-RAT target cell. For example, base station 602 may configure terminal 601 to move to a target cell belonging to E-UTRA carrier frequency x, thus optimally providing VoLTE service to the terminal.

[0177] Figure 7 This illustrates the process by which a terminal sends a measurement result message to a base station in a next-generation mobile communication system according to an embodiment.

[0178] As described above, when measuring frequencies configured by a base station, a terminal can first measure a specific frequency for each RAT based on the base station's configuration. If the intended service (e.g., VoLTE) is optimally provided at a specific frequency, the base station can configure the terminal to first measure the optimal frequency so that it can provide service to the terminal at the optimal frequency. This is because, as described above, the base station provides the terminal with a scheduled handover (HO) message or an RRC connection release message including a redirection CarrierInfo indicating movement to a specific frequency to redirect the terminal to a specific target cell, based on the measurement result message sent by the terminal. For example, when E-UTRA frequency x is a frequency optimized for VoLTE service, when the measurement configuration information (E-UTRA frequency x, E-UTRA frequency y, and E-UTRA frequency z) is configured to the terminal to which the base station intends to provide VoLTE service, the base station can allow the terminal to first measure E-UTRA frequency x and send a measurement result message based thereon to the base station, thereby moving the terminal to a cell belonging to E-UTRA frequency x.

[0179] refer to Figure 7 In step 705, terminal 701 can establish an RRC connection with NR base station 702 to be in RRC connection mode (RRC_CONNECTED).

[0180] In step 710, terminal 701 may send a UECapabilityInformation message to base station 702. For example, such a UECapabilityInformation message may be sent based on a UECapabilityEnquiry request from base station 702. The UECapabilityInformation message may include capability information (new capability bits to support the execution of measurements for each RAT in the order of frequencies listed in MeasConfig) indicating that terminal 701 is capable of performing measurements corresponding to a sequence of measObjects for each RAT included in the measurement configuration information configured in base station 702. The capability information may indicate the terminal's measurement capabilities corresponding to a sequence of measObjects for each RAT included in MeasObjectToAddModList. Alternatively, the capability information may indicate the terminal's measurement capabilities corresponding to a sequence of MeasIDs for each RAT included in MeasIdToAddModList. The capability information may be indicated individually for each RAT. The above information can be indicated individually for each frequency range (FR) or each RAT within each FR, and can also indicate the measurement capabilities of the terminal corresponding to the frequency sequence in MeasObjectToAddModList or MeasIdToAddModList for each FR or each RAT within each FR.

[0181] In step 715, base station 702 may send a predetermined RRC message (e.g., RRCReconfiguration) including measurement configuration information (MeasConfig) to terminal 701. The information included in the measurement configuration information (MeasConfig) may continue as described above.

[0182] For simplicity, the example described is of base station 702 configuring three frequencies for terminal 701 using measurement configuration information: E-UTRA carrier frequency x, E-UTRA carrier frequency y, and E-UTRA carrier frequency z, and sequentially including the three frequencies in MeasObjectToAddModList or MeasIdToAddModList. However, the frequencies and order configured by base station 702 are not limited to this. Each MeasObjectToAddMod included in MeasObjectToAddModList is configured by measObjectId and MeasObject. MeasObjectEUTRA (i.e., one of E-UTRA carrier frequency x, E-UTRA carrier frequency y, and E-UTRA carrier frequency z) can be configured as MeasObject, and MeasObjectToAddModList can sequentially include (measObjectId x, E-UTRA carrier frequency x), (measObjectId y, E-UTRA carrier frequency y), and (measObjectId z, E-UTRA carrier frequency z). For example, each MeasIdToAddMod included in MeasIdToAddModList is configured by measId, measObjectId, and reportConfigId, and MeasIdToAddModList can sequentially include (measId x, measObjectId x, reportConfigId x), (measId y, measObjectId y, reportConfigId y), and (measId z, measObjectId z, reportConfigId z). When configuring measurement configuration information for terminal 701, base station 702 can include and provide an indicator in the measurement configuration information that indicates sequential frequency measurements corresponding to the information present in MeasObjectToAddModList or MeasIdToAddModList. Terminal 701 can sequentially measure E-UTRA carrier frequency x, E-UTRA carrier frequency y, and E-UTRA carrier frequency z according to the indicator. For reference, if an indicator for sequential frequency measurement corresponding to information present in MeasObjectToAddModList or MeasIdToAddModList is configured for both NR and E-UTRA, the measurement configuration information may additionally include an indicator indicating which RAT (Relative Atlas) of NR and E-UTRA is prioritized for frequency measurement. However, if the aforementioned indicator is not present, the terminal may prioritize one of the two RATs for frequency measurement.

[0183] In step 720, terminal 701 can perform measurements based on measurement configuration information received from base station 702. Terminal 701 can measure the configured frequency based on the sequence of measObjects included in MeasObjectToAddModList configured in MeasConfig (i.e., the sequence of E-UTRA frequency x, E-UTRA frequency y, and E-UTRA frequency z). As another example, terminal 701 can perform measurements based on the sequence of measId included in measIdToAddModList(measId x, measObjectId x (i.e., E-UTRA frequency x), reportConfigId 1), (measId y, measObjectId y (i.e., E-UTRA frequency y), reportConfigId 2) and (measId z, measObjectId z (i.e., E-UTRA frequency z), reportConfigId z)). Specific measurement methods can process the above information.

[0184] In step 725, terminal 701 can determine, based on the measurement results from step 720, whether the conditions for reporting a measurement result message (MeasurementReport) to base station 702 have been triggered. Similarly, this determination can continue with the information described above.

[0185] In step 725, when terminal 701 determines that the conditions for reporting the measurement result message have been triggered, terminal 701 can include the measurement results (measResults) for the measId that its measurement reporting process has been triggered in the measurement result message (MeasurementReport) and send it to base station 702. Therefore, terminal 701 can first measure the E-UTRA carrier frequency x and trigger the measurement reporting process based on the associated measId (i.e., measId=x, measObjectId=x, reportConfigId=x). The detailed process of terminal 701 including the measurement results (MeasResults) in the measurement report message can be further described above.

[0186] In step 735, base station 702 may send a predetermined RRC message (e.g., MobilityFromNRCommand or an RRC connection release message including a redirection CarrierInfo indicating movement to a specific frequency) to terminal 701 based on the measurement result message received from terminal 701, so as to redirect the terminal to a specific inter-RAT target cell. For example, base station 702 may configure terminal 701 to move to a target cell belonging to E-UTRA carrier frequency x, and thus provide VoLTE service to terminal 701.

[0187] Figure 8 This illustrates the process by which a terminal sends a measurement result message to a base station in a next-generation mobile communication system according to an embodiment.

[0188] As described above, when measuring frequencies configured by a base station, a terminal can first measure a specific frequency based on the base station's configuration. If the intended service (e.g., VoLTE) is optimally provided at the specific frequency, the base station can configure the terminal to first measure the optimal frequency so that it can provide service to the terminal at the optimal frequency. This is because the base station performs a predetermined RRC message (e.g., a handover message or an RRC connection release message including a redirection CarrierInfo indicating movement to a specific frequency) to redirect the terminal to a specific target cell based on the measurement result message sent by the terminal. For example, when E-UTRA frequency x is a frequency optimized for VoLTE service, when the measurement configuration information (E-UTRA frequency x, E-UTRA frequency y, and E-UTRA frequency z) is configured to the terminal to which the base station intends to provide VoLTE service, the base station can allow the terminal to first measure E-UTRA frequency x and send a measurement result message based thereon to the base station, thereby moving the terminal to a cell belonging to E-UTRA frequency x.

[0189] refer to Figure 8 In step 805, terminal 801 can establish an RRC connection with NR base station 802 to be in RRC connection mode (RRC_CONNECTED).

[0190] In step 810, terminal 801 may send a UECapabilityInformation message to base station 802. For example, such a UECapabilityInformation message may be sent based on a UECapabilityEnquiry from base station 802. The UECapabilityInformation message may include capability information (new capability bits, to support the execution of measurements of each frequency in the order listed in MeasConfig) instructing terminal 801 to first measure specific frequencies included in a frequency list configured by base station 802, according to the configuration of base station 802. For example, the capability information may indicate that priority measurement of at least one measObject including a predetermined indicator is possible based on the sequence in which at least one measObject is included in MeasObjectToAddModList. As another example, capability information may indicate that, based on a sequence in which at least one measId is included in MeasIdToAddModList, priority measurement of at least one measId, including a predetermined indicator for the measId included in each RAT in MeasIdToAddModList, is possible.

[0191] In step 815, base station 802 may send a predetermined RRC message (e.g., RRCReconfiguration) including measurement configuration information (MeasConfig) to terminal 801. The information included in the measurement configuration information (MeasConfig) may continue as described above.

[0192] For simplicity, the example described is the case where base station 802 configures three frequencies—E-UTRA carrier frequency x, E-UTRA carrier frequency y, and E-UTRA carrier frequency z—for terminal 801 using measurement configuration information, and these three frequencies are sequentially included in MeasObjectToAddModList or MeasIdToAddModList. However, the frequencies and order configured by base station 802 are not limited to this. Each MeasObjectToAddMod included in MeasObjectToAddModList is configured by measObjectId and MeasObject. MeasObject EUTRA (i.e., one of E-UTRA carrier frequency x, E-UTRA carrier frequency y, and E-UTRA carrier frequency z) can be configured as MeasObject, and MeasObjectToAddModList can sequentially include (measObjectId x, E-UTRA carrier frequency x), (measObjectId y, E-UTRA carrier frequency y), and (measObjectId z, E-UTRA carrier frequency z). For example, each MeasIdToAddMod included in MeasIdToAddModList is configured by measId, measObjectId, and reportConfigId, and MeasIdToAddModList can include (measId x, measObjectIdx, reportConfigId x), (measId y, measObjectId y, reportConfigId y), and (measId z, measObjectId z, reportConfigId z) in sequence.

[0193] Base station 802 may also set a predetermined indicator for each MeasObject or each MeasId when setting measurement configuration information for terminal 801. For example, the predetermined indicator may be a 1-bit indicator. Therefore, terminal 801 may preferentially perform frequency measurement operations for MeasObjects or MeasIds that include the predetermined indicator, corresponding to the sequence in which the MeasObject or MeasId is included in MeasObjectToAddModList or MeasIdToAddModList. The base station may additionally configure the predetermined indicator for each of the E-UTRA carrier frequencies x and z, such that the terminal first measures the E-UTRA carrier frequencies x and z sequentially, and then measures the E-UTRA carrier frequency y. For reference, frequencies without indicators (e.g., E-UTRA carrier frequency y) do not need to be measured according to the sequence in which the frequencies are included in MeasObjectToAddModList or MeasIdToAddModList. As another example, base station 802 can also be configured, in the form of a bitmap, to determine which of the configured frequencies will be measured first. The bitmap format, i.e., the size or configuration values ​​of the bitmap, can be determined based on the number of MeasurementObjects that base station 802 can configure. Base station 802 can additionally configure, in the form of a bitmap or a list, information indicating which of the configured frequencies will be measured first by terminal 801.

[0194] In step 820, terminal 801 can perform measurements based on measurement configuration information received from base station 802. According to this disclosure, terminal 801 can measure the configured frequencies based on the sequence of measObjects (i.e., the sequence of E-UTRA frequencies x and z) included in the MeasObjectToAddModList configured in MeasConfig. As another example, terminal 801 can perform measurements based on the sequence of measId included in measIdToAddModList(measId x, measObjectId x (i.e., E-UTRA frequency x), reportConfigId 1) and (measId z, measObjectId z (i.e., E-UTRA frequency z), reportConfigId z)). When the measurement of the frequency sequence configured with the predetermined indicator is completed, terminal 801 can measure the remaining frequencies, i.e., E-UTRA frequency y. Specific measurement methods can be implemented according to the information described above.

[0195] In step 825, terminal 801 can determine, based on the measurement results from step 820, whether the conditions for reporting a measurement result message (MeasurementReport) to base station 802 have been triggered. Similarly, this determination can continue with the information described above.

[0196] In step 825, when terminal 801 determines that the conditions for reporting the measurement result message have been triggered, terminal 801 can include the measurement results (measResults) for the measId that its measurement reporting process has been triggered in the measurement result message (MeasurementReport) and send it to base station 802. Therefore, terminal 801 can first measure the E-UTRA carrier frequency x and trigger the measurement reporting process based on its associated measId (i.e., measId=x, measObjectId=x, reportConfigId=x). The detailed process of terminal 801 including the measurement results (MeasResults) in the measurement report message can be further explained above.

[0197] In step 835, base station 802 may send a predetermined RRC message (e.g., MobilityFromNRCommand or an RRC connection release message including redirected carrier information indicating movement to a specific frequency) based on the measurement result message received from terminal 801, in order to redirect terminal 801 to a specific inter-RAT target cell. For example, base station 802 may configure terminal 801 to move to a target cell belonging to E-UTRA carrier frequency x, and thus optimally provide VoLTE service to terminal 801.

[0198] Figure 9 This illustrates the process by which a terminal sends a measurement result message to a base station in a next-generation mobile communication system according to an embodiment.

[0199] When measuring frequencies configured by a base station, a terminal can measure frequencies in order of highest to lowest priority according to the base station's configuration. If VoLTE is optimally provided at a specific frequency, the base station can configure the optimal frequency with the highest priority to provide service to the terminal at the optimal frequency, thereby configuring the terminal to measure the optimal frequency first. This is because the base station performs a predetermined RRC message (e.g., a handover message including a redirection CarrierInfo indicating movement to a specific frequency or an RRC connection release message) based on the measurement result message sent by the terminal to redirect the terminal to a specific target cell as described above. For example, when E-UTRA frequency x is a frequency optimized for VoLTE service, when configuring measurement configuration information (E-UTRA frequency x, E-UTRA frequency y, and E-UTRA frequency z) for a terminal to which the base station intends to provide VoLTE service, the base station can configure the priority of E-UTRA frequency x as the highest, allowing the terminal to measure E-UTRA frequency x first and send a measurement result message based on frequency x to the base station, thereby repositioning the terminal to a cell belonging to E-UTRA frequency x.

[0200] refer to Figure 9 In step 905, terminal 901 can establish an RRC connection with NR base station 902 to be in RRC connection mode (RRC_CONNECTED).

[0201] In step 910, terminal 901 may send a UECapabilityInformation message to base station 902. For example, such a UECapabilityInformation message may be sent based on a UECapabilityEnquiry request from base station 902. The UECapabilityInformation message may include new capability bits to support priority-based measurement execution, which indicate that when the base station configures measurement priorities for each frequency, terminal 901 is able to perform measurements accordingly.

[0202] In step 915, base station 902 may send an RRC message (e.g., RRCReconfiguration) including measurement configuration information (MeasConfig) to terminal 901. The information included in the measurement configuration information (MeasConfig) may continue as described above.

[0203] For simplicity, when configuring three frequencies—E-UTRA carrier frequency x, E-UTRA carrier frequency y, and E-UTRA carrier frequency z—for terminal 901 using measurement configuration information, base station 902 can configure E-UTRA frequency x with the highest priority value, E-UTRA frequency y with the second highest priority value, and E-UTRA frequency z with the lowest priority value. Terminal 901 can apply priorities lower than those configured by base station 902 to frequencies without configured priority values ​​to determine the frequency measurement sequence. As another example, base station 902 can configure terminal 901 to measure specific E-UTRA frequencies first, or determine the maximum number of E-UTRA frequencies based on the base station's configuration.

[0204] In step 920, terminal 901 can perform measurements based on measurement configuration information received from base station 902. Terminal 901 can first measure the frequencies with high priority values ​​among the configured frequencies (the UE measures frequencies in descending priority order). Specific measurement methods can process the aforementioned information.

[0205] In step 925, terminal 901 can determine, based on the measurement results from step 920, whether the conditions for reporting a measurement result message (MeasurementReport) to base station 902 have been triggered. Similarly, this determination can continue with the information described above.

[0206] In step 925, when terminal 901 determines that the conditions for reporting the measurement result message have been triggered, terminal 901 can include the measurement results (measResults) for the measId that its measurement reporting process has been triggered in the measurement result message (MeasurementReport) and send it to base station 902. Therefore, terminal 901 can first measure the E-UTRA carrier frequency x based on the highest priority value configured for the E-UTRA carrier frequency x, and trigger the measurement reporting process for the associated measId (i.e., measId=x, measObjectId=x, reportConfigId=x). The detailed process of terminal 901 including the measurement results (MeasResults) in the measurement report message can be further explained by the information described above.

[0207] In step 935, base station 902 may send a predetermined RRC message (e.g., MobilityFromNRCommand or an RRC connection release message containing a redirection CarrierInfo indicating a move to a specific frequency) based on the measurement result message received from terminal 901, in order to redirect terminal 901 to a specific inter-RAT target cell. For example, base station 902 may configure terminal 901 to relocate to a target cell belonging to E-UTRA carrier frequency x, and thus optimally provide VoLTE service to terminal 901.

[0208] Figure 10 The internal structure of a terminal according to an embodiment is shown.

[0209] Reference Figure 10 The terminal includes a radio frequency (RF) processor 1010, a baseband processor 1020, a storage unit 1030, and a controller 1040.

[0210] RF processor 1010 performs functions for transmitting or receiving signals via a wireless channel, such as signal band changing and amplification. Specifically, RF processor 1010 up-converts the baseband signal provided by baseband processor 1020 to an RF band signal, then transmits the RF band signal through an antenna, and down-converts the RF band signal received through the antenna back to a baseband signal. RF processor 1010 may include transmit filters, receive filters, amplifiers, mixers, oscillators, digital-to-analog converters (DACs), analog-to-digital converters (ADCs), etc. In the figure above, only one antenna is shown, but the terminal may include multiple antennas. RF processor 1010 may include multiple RF links. Furthermore, RF processor 1010 can perform beamforming. To perform beamforming, RF processor 1010 can adjust the phase and magnitude of each signal transmitted or received through multiple antennas or antenna elements. RF processor 1010 can perform MIMO and can receive multiple layers while performing MIMO operation.

[0211] The baseband processor 1020 performs the conversion function between baseband signals and bitstreams according to the system's physical layer specifications. For example, during data transmission, the baseband processor 1020 generates complex symbols by encoding and modulating the transmitted bitstream. Additionally, during data reception, the baseband processor 1020 reconstructs the received bitstream by demodulating and decoding the baseband signal provided from the RF processor 1010. For example, when applying an OFDM scheme, during data transmission, the baseband processor 1020 generates complex symbols by encoding and modulating the transmitted bitstream, maps the complex symbols to a subcarrier, and then configures the OFDM symbols through inverse fast Fourier transform (IFFT) calculation and cyclic prefix (CP) insertion. Furthermore, during data reception, the baseband processor 1020 divides the baseband signal provided from the RF processor 1010 into units of OFDM symbols, reconstructs the signal mapped to the subcarrier through fast Fourier transform (FFT), and then reconstructs the received bitstream through demodulation and decoding.

[0212] As described above, the baseband processor 1020 and the RF processor 1010 transmit and receive signals. Therefore, the baseband processor 1020 and the RF processor 1010 can be referred to as a transmitter, a receiver, a transceiver, or a communication cell. At least one of the baseband processor 1020 and the RF processor 1010 may include multiple communication modules to support a variety of different wireless access technologies. Furthermore, at least one of the baseband processor 1020 and the RF processor 1010 may include different communication modules to process signals in different frequency bands. For example, different wireless access technologies may include wireless LAN, cellular networks (e.g., LTE), etc. Different frequency bands may include ultra-high frequency (SHF) bands (e.g., 2.NR Hertz (Hz), NRhz), millimeter (mm) wave (e.g., 60 GHz) bands, etc.

[0213] Storage unit 1030 stores data such as basic programs, application programs, and configuration information for terminal operation. Specifically, storage unit 1030 may store information related to a second access node performing wireless communication using a second wireless access technology. Storage unit 1030 provides the stored data in response to a request from controller 1040.

[0214] Controller 1040 controls the overall operation of the terminal. For example, controller 1040 sends or receives signals via baseband processor 1020 and RF processor 1010. Controller 1040 records and reads data in storage unit 1030. For this purpose, controller 1040 may include at least one processor. For example, controller 1040 may include a communication processor (CP) that performs control for communication and an application processor that controls higher layers (such as applications).

[0215] Figure 11The diagram illustrates the configuration of an NR base station according to an embodiment.

[0216] Reference Figure 11 The base station includes an RF processor 1110, a baseband processor 1120, a backhaul communication unit 1130, a storage unit 1140, and a controller 1150.

[0217] RF processor 1110 performs functions for transmitting or receiving signals via a wireless channel, such as signal bandgap alteration and amplification. Specifically, RF processor 1110 up-converts a baseband signal provided by baseband processor 1120 to an RF band signal, then transmits the RF band signal through an antenna, and down-converts the RF band signal received through the antenna back to a baseband signal. For example, RF processor 1110 may include transmit filters, receive filters, amplifiers, mixers, oscillators, DACs, ADCs, etc. Only one antenna is shown in this figure, but the first access node may include multiple antennas. RF processor 1110 may include multiple RF chains and can perform beamforming. To perform beamforming, RF processor 1110 can adjust the phase and magnitude of each signal transmitted or received through multiple antennas or antenna elements. The RF processor can perform downlink MIMO operation by transmitting one or more layers.

[0218] The baseband processor 1120 performs the function of converting between baseband signals and bitstreams according to the physical layer specifications of the first radio access technology. For example, during data transmission, the baseband processor 1120 generates complex symbols by encoding and modulating the transmitted bitstream. Additionally, during data reception, the baseband processor 1120 reconstructs the received bitstream by demodulating and decoding the baseband signal provided from the RF processor 1110. For example, when applying an OFDM scheme, during data transmission, the baseband processor 1120 generates complex symbols by encoding and modulating the transmitted bitstream, maps the complex symbols to a subcarrier, and then configures the OFDM symbols through IFFT calculation and CP insertion. Additionally, during data reception, the baseband processor 1120 divides the baseband signal provided from the RF processor 1110 into units of OFDM symbols, reconstructs the signal mapped to the subcarrier through FFT calculation, and then reconstructs the received bitstream through demodulation and decoding. The baseband processor 1120 and the RF processor 1110 transmit and receive signals as described above. Therefore, the baseband processor 1120 and the RF processor 1110 can be referred to as a transmitter, receiver, transceiver, communication unit, or wireless communication unit.

[0219] The backhaul communication unit 1130 provides an interface for performing communication with other nodes within the network. That is, the backhaul communication unit 1130 converts bit streams sent from the primary base station to another node (e.g., an auxiliary base station, the core network, etc.) into physical signals, and converts physical signals received from another node into bit streams.

[0220] Storage unit 1140 stores data such as basic programs, application programs, and configuration information for the operation of the main base station. Specifically, storage unit 1140 may store information related to bearers allocated to connected terminals, measurement results reported from connected terminals, etc. Storage unit 1140 may store information used as a criterion for determining whether to provide or stop providing multiple connections to terminals. Storage unit 1140 then provides the stored data in response to a request from controller 1150.

[0221] The controller 1150 controls the overall operation of the main base station. For example, the controller 1150 transmits or receives signals via the baseband processor 1120 and the RF processor 1110 or via the backhaul communication unit 1130. The controller 1150 records and reads data in the storage unit 1140. For this purpose, the controller 1150 may include at least one processor.

[0222] Although this disclosure has been shown and described with reference to various embodiments thereof, those skilled in the art will understand that various changes in form and detail may be made without departing from the spirit and scope of this disclosure as defined by the appended claims and their equivalents.

Claims

1. A method performed by a base station in a wireless communication system, the method comprising: transmitting, to a terminal, a radio resource control message including configuration information on at least one measurement to be performed by the terminal, the configuration information including first information on a measurement object and second information on a reporting configuration; and receiving, from the terminal, a measurement report including at least one measurement result based on the configuration information, wherein the first information includes information indicating a measurement sequence of a corresponding measurement object among the measurement object. 2.The method of claim 1, further comprising: receiving, from the terminal, capability information including information indicating whether the terminal supports a measurement based on a configured measurement sequence, the measurement including at least one of an intra-radio access technology measurement and an inter-radio access technology measurement. 3.The method of claim 1, wherein the measurement object including a first measurement object and a second measurement object, and wherein the first information includes information on a first value indicating that the first measurement object is measured first and information on a second value indicating that the second measurement object is measured second. 4.The method of claim 1, wherein the measurement sequence for at least one of the measurement object is not provided in the first information, and wherein the measurement object includes a measurement object for new radio or a measurement object for evolved universal mobile telecommunication system terrestrial radio access. 5.A method performed by a terminal in a wireless communication system, the method comprising: receiving, from a base station, a radio resource control message including configuration information on at least one measurement to be performed by the terminal, the configuration information including first information on a measurement object and second information on a reporting configuration; and transmitting, to the base station, a measurement report including at least one measurement result based on the configuration information; wherein the first information includes information indicating a measurement sequence of a corresponding measurement object among the measurement object. 6.The method of claim 5, further comprising: transmitting, to the base station, capability information including information indicating whether the terminal supports a measurement based on a configured measurement sequence, the measurement including at least one of an intra-radio access technology measurement and an inter-radio access technology measurement. 7.The method of claim 5, wherein the measurement object including a first measurement object and a second measurement object, and wherein the first information includes information on a first value indicating that the first measurement object is measured first and information on a second value indicating that the second measurement object is measured second. 8.The method of claim 5, wherein the measurement sequence for at least one of the measurement object is not provided in the first information, and wherein the measurement object includes a measurement object for new radio or a measurement object for evolved universal mobile telecommunication system terrestrial radio access. 9.A base station in a wireless communication system, the base station comprising: a transceiver; and a controller configured to: ​ controlling the transceiver to transmit, to a terminal, a radio resource control message including configuration information on at least one measurement to be performed by the terminal, the configuration information including first information on a measurement object and second information on a reporting configuration, and controlling the transceiver to receive, from the terminal, a measurement report including at least one measurement result based on the configuration information, wherein the first information includes information indicating a measurement sequence of a corresponding measurement object among the measurement object.

10. The base station of claim 9, wherein the controller is further configured to control the transceiver to receive, from the terminal, capability information including information indicating whether the terminal supports a measurement based on a configured measurement sequence, the measurement including at least one of intra-radio access technology measurement and inter-radio access technology measurement.

11. The base station of claim 9, wherein the measurement object includes a first measurement object and a second measurement object, and wherein the first information includes information on a first value indicating that the first measurement object is measured first and information on a second value indicating that the second measurement object is measured second.

12. The base station of claim 9, wherein the measurement sequence for at least one measurement object among the measurement object is not provided in the first information, and wherein the measurement object includes a measurement object for new radio or a measurement object for evolved universal mobile telecommunications system terrestrial radio access.

13. A terminal in a wireless communication system, the terminal comprising: a transceiver; and a controller configured to: control the transceiver to receive, from a base station, a radio resource control message including configuration information on at least one measurement to be performed by the terminal, the configuration information including first information on a measurement object and second information on a reporting configuration, and control the transceiver to transmit, to the base station, a measurement report including at least one measurement result based on the configuration information, wherein the first information includes information indicating a measurement sequence of a corresponding measurement object among the measurement object.

14. The terminal of claim 13, wherein the controller is further configured to control the transceiver to transmit, to the base station, capability information including information indicating whether the terminal supports a measurement based on a configured measurement sequence, the measurement including at least one of intra-radio access technology measurement and inter-radio access technology measurement.

15. The terminal of claim 13, wherein the measurement object includes a first measurement object and a second measurement object, and wherein the first information includes information on a first value indicating that the first measurement object is measured first and information on a second value indicating that the second measurement object is measured second.

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