Method and apparatus for updating list of cells to be measured when reselecting cells

Abstract

The present disclosure relates to a method of operating a terminal, comprising: receiving a radio resource control (RRC) release message from a base station, the message comprising duration information and active area information for measurement in an RRC idle state, where the active area information indicates a frequency list and a cell list; in response to receiving the RRC release message, entering an RRC idle state and starting a timer having a value set to the duration information; performing measurement in an RRC idle state based on the first carrier list information while the timer is running; and identifying whether a reselected cell needs measurement in an RRC idle state based on a frequency and a physical cell identity of a serving cell and a frequency list and a cell list indicated by the active area information in a case where cell reselection is performed while the timer is running; and stopping the timer if the measurement in the RRC idle state is not required by the reselected cell.

Description

[0001] This case is a divisional application of an invention patent application with an application date of February 10, 2020, application number 202080019671.6, and invention name "Method and device for updating the list of cells to be measured when reselecting cells in idle mode in the next generation wireless communication system". Technical Field

[0002] The disclosure relates to a method for a terminal in an idle state to update a list of cells to be measured when reselecting a cell, and an apparatus for performing the method.

[0003] The disclosure also relates to a method for collecting and reporting idle mode measurement information in a next generation mobile communication system and an apparatus for performing the method. Background Art

[0004] In order to meet the demand for wireless data traffic that has increased since the deployment of 4G communication systems, efforts have been made to develop improved 5G or quasi-5G communication systems. Therefore, 5G or pre-5G communication systems are also referred to as "super 4G 'networks'" or "post-LTE systems". 5G communication systems are considered to be implemented in higher frequency (mmWave) bands (e.g., 60GHz bands) in order to achieve higher data rates. In order to reduce the propagation loss of radio waves and increase the transmission distance, beamforming, massive multiple-input multiple-output (MIMO), full-size MIMO (FD-MIMO), array antennas, analog beamforming, and large antenna technology are discussed in 5G communication systems. In addition, in 5G communication systems, system network improvements are being developed based on advanced small cells, cloud radio access networks (RANs), ultra-dense networks, device-to-device (D2D) communications, wireless backhaul, mobile networks, collaborative communications, multi-point collaboration (CoMP), receiving-end interference elimination, etc. In 5G systems, hybrid FSK and QAM modulation (FQAM) and sliding window superposition coding (SWSC) have been developed as advanced coded modulation (ACM), and filter bank multi-carrier (FBMC), non-orthogonal multiple access (NOMA) and sparse code multiple access (SCMA) as advanced access technologies.

[0005] The Internet, as a human-centered connection network in which people produce and consume information, is now evolving into the Internet of Things (IoT), in which distributed entities such as things exchange and process information without human intervention. The Internet of Everything (IoE) has emerged as a combination of IoT technology and big data processing technology through connection with cloud servers. Since IoT implementation requires technical elements such as "sensing technology", "wired / wireless communication and network infrastructure", "service interface technology", and "security technology", in recent years, sensor networks, machine-to-machine (M2M) communication, machine type communication (MTC), etc. have been studied. Such an IoT environment can provide smart Internet technology services that create new value for human life by collecting and analyzing data generated between connected things. Through the integration and combination between existing information technology (IT) and various industrial applications, IoT can be applied to various fields, including smart homes, smart buildings, smart cities, smart cars or connected cars, smart grids, healthcare, smart appliances, and advanced medical services.

[0006] In line with this, various attempts have been made to apply 5G communication systems to IoT networks. For example, technologies such as sensor networks, machine type communications (MTC), and machine-to-machine (M2M) communications can be implemented through beamforming, MIMO, and array antennas. The application of cloud radio access networks (RANs) as the above-mentioned big data processing technology can also be considered as an example of the fusion between 5G technology and IoT technology.

[0007] The above information is presented as background information only to assist with understanding the present disclosure. No determination is made, and no assertion is made, as to whether any of the above may be applicable as prior art with respect to the present disclosure. Summary of the invention

[0008] Technical issues

[0009] The disclosure relates to a technology for improving carrier aggregation technology applied to LTE systems and next-generation mobile communication systems, wherein a terminal in an idle state can measure neighboring cells, can record its measurement values, can establish an RRC connection with a specific cell, and can send the stored measurement values ​​of the neighboring cells to a base station, and the base station can send an instruction for quickly configuring and activating carrier aggregation to the terminal. However, in conventional operations, since the terminal in idle mode continues to use the idle mode measurement cell list configured by the previous cell, accurate measurement is difficult when reselecting a cell, and the corresponding cell list needs to be updated.

[0010] In addition, the terminal has a supportable subcarrier spacing (SCS), and there is an SCS that can be supported in a specific frequency. If the SCS supported by the terminal is not supported in a specific frequency, the terminal cannot use the frequency. Therefore, even if the terminal performs an idle mode measurement operation on the frequency and reports the operation, the frequency cannot be used. Therefore, it is wasteful to perform an idle mode measurement operation on the frequency.

[0011] Problem Solution

[0012] In order to solve the above problems, a method for operating a terminal in a wireless communication system is disclosed, the method comprising: receiving an idle mode measurement configuration from a base station; when the terminal enters the idle mode, performing idle mode measurement based on the measurement configuration; when the terminal enters the connected mode, generating a measurement result based on the result of performing the measurement; and reporting the measurement result to the base station, wherein the measurement result of the carrier frequency included in the carrier frequency list included in the measurement configuration and not supporting the subcarrier spacing (SCS) supported by the terminal is not reported.

[0013] In order to solve the above problems, the present invention also discloses a method for operating a base station in a wireless communication system, the method comprising: sending an idle mode measurement configuration to a terminal; performing a radio resource control (RRC) connection process to switch the terminal from an idle mode to a connected mode; and receiving measurement results measured in the idle mode from the terminal, wherein the measurement results of the carrier frequencies included in the carrier frequency list included in the measurement configuration and which do not support the subcarrier spacing (SCS) supported by the terminal are not reported.

[0014] In order to solve the above problems, the present invention also discloses a terminal in a wireless communication system, wherein the terminal includes: a transceiver; and a controller, configured to receive an idle mode measurement configuration from a base station through the transceiver when the terminal enters an idle mode, perform idle mode measurement based on the measurement configuration when the terminal enters a connected mode, generate a measurement result based on the result of performing the measurement, and report the measurement result to the base station through the transceiver, wherein the measurement result of the carrier frequency included in the carrier frequency list included in the measurement configuration and the carrier frequency that does not support the subcarrier spacing (SCS) supported by the terminal is not reported.

[0015] In order to solve the above problems, the present invention also discloses a base station in a wireless communication system, wherein the base station includes: a transceiver; and a controller, configured to send an idle mode measurement configuration to a terminal through the transceiver, perform a radio resource control (RRC) connection process to switch the terminal from idle mode to connected mode, and receive measurement results measured in idle mode from the terminal through the transceiver, wherein measurement results of carrier frequencies that do not support subcarrier spacing (SCS) supported by the terminal among carrier frequencies included in a carrier frequency list included in the measurement configuration are not reported.

[0016] In order to solve the above-mentioned problem, a method for operating a terminal in a wireless communication system is disclosed, the method comprising: receiving a radio resource control (RRC) release message from a base station, the message comprising duration information and valid area information for measurement in an RRC idle state, wherein the valid area information indicates a frequency list and a cell list; as a response to receiving the RRC release message, entering an RRC idle state and starting a timer having a value set to the duration information; while the timer is running, performing measurement in the RRC idle state based on first carrier list information, wherein the first carrier list message is stored in the terminal based on the RRC release message; and in a case where cell reselection is performed when the timer is running, identifying whether the reselected cell requires measurement in the RRC idle state based on the frequency and physical cell identity of the serving cell and the frequency list and cell list indicated by the valid area information; and stopping the timer in a case where measurement in the RRC idle state is not required by the reselected cell.

[0017] In order to solve the above-mentioned problem, the disclosure also provides a method for operating a base station in a wireless communication system, the method comprising: identifying a radio resource control RRC release message, the message including duration information and valid area information for measurement in an RRC idle state, wherein the valid area information indicates a frequency list and a cell list; and sending an RRC release message to a terminal; wherein the RRC release message instructs the terminal to enter an RRC idle state and start a timer having a value set to the duration information, wherein, when the timer is running, first carrier list information identified based on the RRC release message is used to perform measurement in the RRC idle state, wherein, in a case where cell reselection is performed when the timer is running, whether the reselected cell requires measurement in the RRC idle state is identified based on the frequency and physical cell identifier of the serving cell and the frequency list and cell list indicated by the valid area information, and wherein, in a case where measurement in the RRC idle state is not required by the reselected cell, the timer is stopped.

[0018] In order to solve the above problems, the present invention also discloses a terminal in a wireless communication system, the terminal comprising: a transceiver; and a controller, coupled to the transceiver and configured to: receive a radio resource control (RRC) release message from a base station, the message comprising duration information and valid area information for measurement in an RRC idle state, wherein the valid area information indicates a frequency list and a cell list, enter an RRC idle state and start a timer having a value set to the duration information as a response to receiving the RRC release message; perform measurement in the RRC idle state based on first carrier list information when the timer is running, wherein the first carrier list message is stored in the terminal based on the RRC release message, and in a case where cell reselection is performed when the timer is running, identify whether the reselected cell requires measurement in the RRC idle state based on the frequency and physical cell identifier of the serving cell and the frequency list and cell list indicated by the valid area information, and stop the timer if measurement in the RRC idle state is not required by the reselected cell.

[0019] In order to solve the above problems, the disclosure also provides a base station in a wireless communication system, the base station comprising: a transceiver; and a controller, coupled to the transceiver and configured to: identify a radio resource control RRC release message, the message comprising duration information and valid area information for measurement in an RRC idle state, wherein the valid area information indicates a frequency list and a cell list, and send an RRC release message to a terminal, wherein the RRC release message instructs the terminal to enter an RRC idle state and start a timer with a value set to the duration information, wherein when the timer is running, first carrier list information identified based on the RRC release message is used to perform measurement in the RRC idle state, wherein, in a case where cell reselection is performed when the timer is running, whether the reselected cell needs measurement in the RRC idle state is identified based on the frequency and physical cell identifier of the serving cell and the frequency list and cell list indicated by the valid area information, and wherein, in a case where measurement in the RRC idle state is not required by the reselected cell, the timer is stopped.

[0020] Beneficial Effects

[0021] A method for updating a cell list for measurement by a terminal in idle mode is disclosed, which enables carrier aggregation performed by existing terminals to be improved, i.e., enables a terminal in idle mode to accurately perform measurements of neighboring cells for fast carrier aggregation even when reselecting a cell.

[0022] In addition, the disclosure enables the terminal to perform idle mode measurement operations only on frequencies supported by the terminal (such as SCS), thereby reducing UE complexity.

[0023] Before proceeding to the following detailed description, it may be helpful to set forth definitions of certain words and phrases used throughout this patent document: the terms "include" and "comprising" and their derivatives mean including but not limited to; the term "or" is inclusive, meaning and / or; the phrases "associated with" and "associated with" and their derivatives may mean including, included within, interconnected with, containing, contained within, connected to or connected with, coupled to or coupled with, communicable with, cooperating with, interleaved, juxtaposed, proximate to, bound to or bound with, having, having the property of, etc.; and the term "controller" means any device, system, or portion thereof that controls at least one operation, such device may be implemented in hardware, firmware, or software, or some combination of at least two thereof. It should be noted that the functionality associated with any particular controller may be centralized or distributed, whether locally or remotely.

[0024] In addition, the various functions described below can be implemented or supported by one or more computer programs, each of which is formed by a computer-readable program code and implemented in a computer-readable medium. The terms "application" and "program" refer to one or more computer programs, software components, instruction sets, processes, functions, objects, classes, instances, related data or a part thereof that are suitable for being implemented in a suitable computer-readable program code. The phrase "computer-readable program code" includes any type of computer code, including source code, object code and executable code. The phrase "computer-readable medium" includes any type of medium that can be accessed by a computer, such as a read-only memory (ROM), a random access memory (RAM), a hard drive, a compact disc (CD), a digital video disc (DVD) or any other type of memory. "Non-transitory" computer-readable media does not include wired, wireless, optical or other communication links that transmit temporary electrical signals or other signals. Non-transitory computer-readable media include media that can permanently store data and media that can store data and rewrite it later, such as rewritable optical discs or erasable memory devices.

[0025] Definitions for certain words and phrases are provided throughout this patent document. Those of ordinary skill in the art should understand that in many, if not most instances, such definitions apply to prior, as well as future uses of such defined words and phrases. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] For a more complete understanding of the disclosure and its advantages, reference is now made to the following description taken in conjunction with the accompanying drawings, wherein like reference numerals refer to like parts:

[0027] Figure 1A is a diagram illustrating a structure of an LTE system for reference in order to explain the disclosure;

[0028] Figure 1B is a diagram illustrating a radio protocol structure of an LTE system for reference in order to explain the disclosure;

[0029] Figure 1C is a diagram illustrating a structure of a next-generation mobile communication system to which the present disclosure is applied;

[0030] Figure 1D is a diagram illustrating a radio protocol structure of a next-generation mobile communication system to which the present disclosure can be applied;

[0031] Figure 1E is a diagram illustrating an overall operation of a terminal switching to a connected state, measuring a neighboring cell, and performing carrier aggregation in an LTE system according to the disclosure;

[0032] Figure 1F is a diagram illustrating an overall operation of a terminal measuring a neighboring cell and reporting the cell to a base station in an idle state in an LTE system or an NR system according to the disclosure so as to quickly activate carrier aggregation after switching from the idle state to an RRC connected state;

[0033] Figure 1G is a diagram illustrating a conventional idle mode measurement operation of a terminal when reselecting a cell for reference in the disclosure;

[0034] Figure 1H is a diagram illustrating a method in which a terminal updates idle mode measurement information when a cell is reselected according to Embodiment 1 of an operation of a terminal proposed in the disclosure;

[0035] Fig. 1I is a diagram illustrating a method of performing idle mode measurement based on frequency information of a base station supporting an enhanced CA function according to Embodiment 2 of the operation of a terminal proposed in the disclosure;

[0036] Figure 1J is a block diagram illustrating an internal structure of a terminal disclosed by an application;

[0037] Figure 1K is a block diagram illustrating a configuration of a base station according to the disclosure;

[0038] Figure 2A is a diagram illustrating a structure of an LTE system according to an embodiment;

[0039] Figure 2B is a diagram illustrating a radio protocol structure in an LTE system according to an embodiment;

[0040] Figure 2C is a diagram illustrating a structure of a next generation mobile communication system according to an embodiment;

[0041] Figure 2D is a diagram illustrating a radio protocol structure of a next generation mobile communication system according to an embodiment;

[0042] Figure 2E is a diagram illustrating a process in which a terminal that does not support idle mode measurement establishes an RRC connection with a base station and switches from the RRC idle mode to the RRC connected mode, and a process in which the base station configures carrier aggregation (hereinafter referred to as "CA") for the terminal;

[0043] Figure 2F is a diagram illustrating a process in which a terminal supporting idle mode measurement releases an RRC connection with a base station and performs idle mode measurement, and a process in which the base station configures carrier aggregation (hereinafter referred to as “CA”) to the terminal based on the idle mode measurement result;

[0044] Figure 2G is a flow chart illustrating the operation of the terminal in the disclosure;

[0045] Figure 2H is a flow chart illustrating the operation of a base station in the disclosure;

[0046] Fig.2I is a diagram illustrating a structure of a terminal according to an embodiment; and

[0047] Figure 2J is a diagram illustrating a structure of a base station according to an embodiment. DETAILED DESCRIPTION

[0048] Discussed below Figures 1A to 2J The various embodiments used to describe the principles of the present disclosure in this patent document are illustrative only and should not be interpreted in any way to limit the scope of the disclosure. Those skilled in the art will understand that the principles of the present disclosure can be implemented in any appropriately arranged system or device.

[0049] Hereinafter, the operating principle of the disclosure will be described in detail with reference to the accompanying drawings. When describing the disclosure below, when it is determined that a detailed description of the relevant known configuration or function incorporated herein may unnecessarily obscure the subject matter of the disclosure, the detailed description of the relevant known configuration or function will be omitted. The terms to be described below are terms defined in consideration of the functions in the disclosure, and may differ according to the user, the user's intention or habit. Therefore, the definition of the terms should be based on the content of the entire specification. In the following description, for the convenience of description, terms for identifying access nodes, terms indicating network entities, terms indicating messages, terms indicating interfaces between network entities, and terms indicating various identification information are used. Therefore, the disclosure is not limited to the following terms, and other terms with the same technical meaning may be used.

[0050] For convenience of description, the disclosure uses terms and names defined in 3GPP LTE (3rd Generation Partnership Project Long Term Evolution). However, the disclosure is not limited to the terms and names and may be equally applied to a system based on another standard.

[0051] Figure 1A is a diagram illustrating a structure of an LTE system which is a reference for the disclosed description.

[0052] refer to Figure 1A , the radio access network of the LTE system may include evolved Node Bs (hereinafter, referred to as "eNBs", "Node Bs" or "base stations") 1a-05, 1a-10, 1a-15 and 1a-20, a mobility management entity (MME) 1a-25 and a serving gateway (S-GW) 1a-30. User equipment (hereinafter referred to as "UE" or "terminal") 1a-35 accesses an external network through the eNBs 1a-05 to 1a-20 and the S-GW 1a-30.

[0053] exist Figure 1A In the LTE system, eNB 1a-05 to 1a-20 correspond to the existing Node B of UMTS. The eNB is connected to the UE 1a-35 via a radio channel and can play a more complex role than the existing Node B. In the LTE system, all user traffic including real-time services such as Voice over IP (VoIP) over Internet Protocol is served by a shared channel. Therefore, a device for collecting status information such as the buffer status of the UE, the available transmission power status, and the channel status and performing scheduling is required. The eNB 1a-05 to 1a-20 can be used as such a device.

[0054] One eNB usually controls multiple cells. For example, in order to achieve a data rate of 100 Mbps, the LTE system uses orthogonal frequency division multiplexing (hereinafter referred to as "OFDM") as a radio access technology in, for example, a 20 MHz bandwidth. In addition, an adaptive modulation and coding (hereinafter referred to as "AMC") scheme is applied to determine the modulation scheme and channel coding rate according to the channel state of the terminal. S-GW 1a-30 is a device for providing data bearers, and generates or removes data bearers under the control of MME 1a-25. MME 1a-25 is a device that performs various control functions and mobility management functions of the terminal, and can be connected to multiple base stations.

[0055] Figure 1B is a diagram illustrating a radio protocol structure of an LTE system which is a reference for the disclosed description.

[0056] refer to Figure 1B, the radio protocol of the LTE system includes Packet Data Convergence Protocol (PDCP) 1b-05 or 1b-40, Radio Link Control (RLC) 1b-10 or 1b-35, and Medium Access Control (MAC) 1b-15 or 1b-30 in the terminal and eNB, respectively. PDCP 1b-05 or 1b-40 performs operations such as IP header compression / decompression. The main functions of PDCP are summarized as follows.

[0057] -Header compression and decompression (ROHC only)

[0058] -Transmission of user data

[0059] - For RLC AM, in-sequence delivery of higher layer PDUs during PDCP re-establishment

[0060] - Sequence reordering {For split bearer in DC (supports RLC AM only): PDCP PDU routing for transmission and PDCP PDU reordering for reception}

[0061] - For RLC AM, repeat detection of lower layer SDUs during PDCP re-establishment

[0062] - For RLC AM, retransmit PDCP SDUs at handover, and for split bearers in DC, retransmit PDCP PDUs during PDCP data recovery

[0063] -Encryption and decryption

[0064] - Timer based SDU discard in uplink.

[0065] Radio Link Control (hereinafter also referred to as "RLC") 1b-10 or 1b-35 reconfigures a PDCP PDU (Packet Data Unit) into an appropriate size and performs an ARQ operation, etc. The main functions of the RLC are summarized as follows.

[0066] -Data transmission function (transmission of high-level PDU)

[0067] -ARQ function {Error correction through ARQ (only for AM data transmission)}

[0068] -RLC SDU concatenation, segmentation and reassembly (only for UM and AM data transmission)

[0069] - Re-segmentation of RLC data PDU (only for AM data transmission)

[0070] - Reordering of RLC data PDUs (only for UM and AM data transmission)

[0071] - Duplicate detection (for UM and AM data transmission only)

[0072] -Protocol error detection (for AM data transmission only)

[0073] -RLC SDU discard (only for UM and AM data transmission)

[0074] -RLC reconstruction

[0075] MAC 1b-15 or 1b-30 is connected to a plurality of RLC entities configured in a single terminal, multiplexes RLC PDUs into MAC PDUs, and demultiplexes RLC PDUs from MAC PDUs. The main functions of MAC are summarized as follows.

[0076] - Mapping between logical channels and transport channels

[0077] - Multiplexing / demultiplexing MAC SDUs belonging to one or different logical channels to / from transport blocks (TBs) delivered to the physical layer on transport channels

[0078] -Dispatch information report

[0079] -HARQ function (error correction through HARQ)

[0080] - Priority handling between logical channels of a UE

[0081] - Priority handling between UEs through dynamic scheduling

[0082] -MBMS service logo

[0083] -Transmission format selection

[0084] -filling

[0085] The physical layers 1b-20 and 1b-25 channel encode and modulate the high-layer data, convert it into OFDM symbols, and then send it through the radio channel, or demodulate the OFDM symbols received through the radio channel and channel decode them, and then send them to the high layer. In addition, the physical layer uses hybrid ARQ (HARQ) for additional error correction, and the receiving entity sends 1-bit information indicating whether the packet sent by the sending entity is received. This is called "HARQ ACK / NACK" information. Downlink HARQ ACK / NACK information for uplink transmission can be sent through the physical hybrid ARQ indicator channel (PHICH), and uplink HARQ ACK / NACK information for downlink transmission can be sent through the physical uplink control channel (PUCCH) or the physical uplink shared channel (PUSCH).

[0086] Meanwhile, the PHY layer may include one or more frequencies / carriers, and a technique for configuring and using multiple frequencies at the same time is called "carrier aggregation" (hereinafter referred to as "CA"). CA may also use one or more subcarriers, as well as a primary carrier, thereby significantly increasing the amount of transmission by the number of subcarriers compared to existing communications between a terminal {or user equipment (UE)} and a base station {E-UTRAN Node B (eNB)} that can use only a single carrier. Meanwhile, in LTE, a cell in a base station using a primary carrier is called a "primary cell" (PCell), and a cell using a subcarrier is called a "secondary cell" (SCell).

[0087] Although not shown in the figure, an RRC (Radio Resource Control) (hereinafter referred to as "RRC") layer is above the PDCP layer of the terminal and the base station, respectively, and the RRC layer can transmit and receive configuration control messages related to connection and measurement for radio resource control.

[0088] Figure 1C is a diagram illustrating a structure of a next-generation mobile communication system to which disclosure is applied.

[0089] refer to Figure 1C , the radio access network of the next generation mobile communication system includes a new radio node B (hereinafter referred to as "NR gNB" or "NR base station") 1c-10 and a new radio core network (NR CN) 1c-05. The new radio user equipment (hereinafter referred to as "NR UE" or "terminal") 1c-15 accesses the external network through the NR gNB 1c-10 and the NR CN 1c-05.

[0090] exist Figure 1C In the present invention, NR gNB 1c-10 corresponds to the evolved Node B (eNB) in the existing LTE system. NR gNB is connected to NR UE 1c-15 through a radio channel and can provide services superior to the existing Node B. In the next generation mobile communication system, all user traffic is served through a shared channel. Therefore, a device is required for collecting status information such as the buffer status, available transmission power status, and channel status of the UE and performing scheduling. NR gNB 1c-10 is used as such a device. In general, one NR NB can control multiple cells. In order to achieve an ultra-high data rate compared to the existing LTE system, the next generation mobile communication system can have a bandwidth equal to or greater than the maximum bandwidth of the existing system. In addition, the next generation mobile communication system can use orthogonal frequency division multiplexing (OFDM) as a radio access technology, and in addition to this, beamforming technology can be adopted.

[0091] In addition, an adaptive modulation and coding (hereinafter referred to as "AMC") scheme can be applied to determine the modulation scheme and channel coding rate according to the channel state of the terminal. NR CN 1c-05 performs functions such as mobility support, bearer configuration, and QoS configuration. NR CN is a device that performs various control functions as well as mobility management functions of the terminal, and can be connected to multiple base stations. In addition, the next-generation mobile communication system can be interoperable with the existing LTE system, and the NR CN can be connected to the MME 1c-25 through a network interface. The MME can be connected to the eNB 1c-30, which is an existing base station in the network 1c-20 with the NR gNB 1c-10.

[0092] Figure 1D is a diagram illustrating a radio protocol structure of a next-generation mobile communication system to which the disclosure can be applied.

[0093] refer to Figure 1D The radio protocols of the next generation mobile communication system include NRSDAP 1d-01 or 1d-45, NR PDCP 1d-05 or 1d-40, NR RLC 1d-10 or 1d-35, NR MAC 1d-15 or 1d-30 and NR PHY 1d-20 or 1d-25 in the terminal and NR base station respectively.

[0094] The main functions of NR SDAP 1d-01 or 1d-45 may include some of the following functions.

[0095] -Transmission of user plane data

[0096] - Mapping between QoS flows and DRBs for downlink and uplink

[0097] - Marking of QoS flow ID in both downlink and uplink packets

[0098] - Mapping of Reflective QoS Flows to DRBs for UL SDAP PDUs

[0099] Regarding the SDAP layer entity, the terminal may receive, through an RRC message, a header indicating whether to use the SDAP layer entity or a configuration of the functions of the SDAP layer entity for each PDCP layer entity, for each bearer, or for each logical channel. When the SDAP header is configured, the 1-bit NAS reflection QoS configuration indicator and the 1-bit AS reflection QoS configuration indicator of the SDAP header may indicate that the terminal updates or reconfigures the mapping information between the QoS flow and the data bearers in the uplink and downlink. The SDAP header may include QoS flow ID information indicating QoS. QoS information can be used as data processing priority, scheduling information, etc. to support effective services.

[0100] The main functions of NR PDCP 1d-05 or 1d-40 may include some of the following functions.

[0101] -Header compression and decompression (ROHC only)

[0102] -Transmission of user data

[0103] - In-sequence delivery of higher-level PDUs

[0104] - Out-of-order delivery of higher-level PDUs

[0105] -Sequence reordering (for received PDCP PDU reordering)

[0106] - Duplicate detection of lower layer SDUs

[0107] -Retransmission of PDCP SDU

[0108] -Encryption and decryption

[0109] - Timer-based SDU discard in uplink

[0110] The above-mentioned reordering function of the NR PDCP entity may refer to a function of reordering the PDCP PDU received from the lower layer based on the PDCP sequence number (SN). The reordering function of the NR PDCP entity may include a function of sending data to the upper layer in a reordered order, a function of directly sending data to the upper layer without considering its order, a function of reordering the sequence and recording the lost PDCP PDU, a function of sending a status report of the lost PDCP PDU to the transmitting end, and a function of requesting retransmission of the lost PDCP PDU.

[0111] The main functions of NR RLC 1d-10 or 1d-35 may include some of the following functions.

[0112] -Data transmission function (transmission of high-level PDU)

[0113] - In-sequence delivery of higher-level PDUs

[0114] - Out-of-order delivery of higher-level PDUs

[0115] -ARQ function (error correction through ARQ)

[0116] - Concatenation, segmentation and reassembly of RLC SDU

[0117] - Re-segmentation of RLC data PDUs

[0118] - Reordering of RLC data PDUs

[0119] - Duplicate detection

[0120] -Protocol error detection

[0121] -RLC SDU discarded

[0122] -RLC reconstruction

[0123] The above-mentioned in-sequence delivery function of the NR RLC entity may refer to a function of transmitting the RLC SDU received from the lower layer to the higher layer in sequence. The in-sequence delivery function of the NR RLC entity may include a function of reassembling and sending an original RLC SDU if the original RLC SDU is divided into a plurality of RLC SDUs and is received, may include a function of reordering the received RLC PDU based on the RLC sequence number (SN) or the PDCP sequence number (SN), may include a function of reordering the sequence and recording the lost RLC PDU, may include a function of sending a status report of the lost RLC PDU to the transmitting end, and may include a function of requesting retransmission of the lost RLC PDU. The in-sequence delivery function of the NR RLC entity may include a function of sending only the RLC SDU before the lost RLC SDU to the higher layer in sequence if there is a lost RLC SDU, may include a function of sending all RLC SDUs received before the timer starts to the higher layer in sequence if there is a lost RLC SDU, or may include a function of sending all RLC SDUs received until the time point is received in sequence if there is a lost RLC SDU but the predetermined timer expires. In addition, the RLC PDUs may be processed in the order of receipt (in the order of arrival, regardless of the order of sequence numbers or sequence numbers) and may be sent to the PDCP entity in an out-of-order delivery manner. In the case of receiving segments, the NR RLC entity may receive segments stored in a buffer or to be received later, may reconfigure them into a complete RLC PDU, and may process the RLC PDU and send it to the PDCP. The NR RLC layer may not include a cascading function, which may be performed in the NR MAC layer or may be replaced by a multiplexing function of the NR MAC layer.

[0124] In the above description, the out-of-order delivery of the NR RLC entity may refer to a function of directly delivering the RLC SDU received from the lower layer to the higher layer regardless of its order. The out-of-order delivery of the NR RLC entity may include a function of reassembling and delivering an original RLC SDU if it is divided into a plurality of RLC SDUs and received, and may include a function of storing and sorting the RLC SN or PDCP SN of the received RLC PDU, thereby recording the lost RLC PDU.

[0125] NR MAC 1d-15 or 1d-30 can be connected to multiple NR RLC entities configured in a single terminal, and the main functions of NR MAC may include some of the following functions.

[0126] - Mapping between logical channels and transport channels

[0127] -Multiplexing / demultiplexing of MAC SDU

[0128] -Dispatch information report

[0129] -HARQ function (error correction through HARQ)

[0130] - Priority handling between logical channels of a UE

[0131] - Priority handling between UEs through dynamic scheduling

[0132] -MBMS service logo

[0133] -Transmission format selection

[0134] -filling

[0135] NR PHY layers 1d-20 and 1d-25 can perform operations of channel encoding and modulating high-layer data into OFDM symbols and sending them through a radio channel, or demodulating and channel decoding OFDM symbols received through a radio channel and sending them to a high layer.

[0136] Figure 1E is a diagram illustrating overall operations of a terminal switching to a connected state, measuring a neighboring cell, and performing carrier aggregation in an LTE system according to the disclosure.

[0137] Reselecting a cell is a process in which a terminal determines a cell to reside in when the service quality of the serving cell is lower than that of a neighboring cell due to the movement of a terminal in an idle state (or idle mode). The handover is determined by the network (MME or source eNB), while the cell reselection is determined by the terminal based on measurement values. In addition, the cell reselected by the mobile terminal can be a cell using the same LTE frequency as the serving cell on which the terminal is currently camping (same-frequency cell), a cell using a different LTE frequency from the serving cell (different-frequency cell), or a cell using another radio access technology (inter-RAT cell).

[0138] The terminal 1e-01 in the idle state performs a series of operations while residing on the serving cell (1e-05). First, the terminal can receive a system information block (SIB) broadcast by the base station 1e-02 of the serving cell (1e-10). For reference, MIB, SIB1 and SIB2 are system information commonly applied to all terminals, and for example, SIB3 to SIB8 may include information for the terminal in the idle state to reselect the cell. Specifically, information related to the measurement of adjacent cells in the LTE frequency (same-frequency measurement) can be sent through SIB4, and information related to different-frequency measurement can be sent through SIB5. The system information may include at least one of a threshold for determining whether to measure an adjacent cell signal, a parameter for calculating the rank of the serving cell and the adjacent cell, etc. In addition, for the same-frequency measurement, since the carrier frequency is the same as the current serving cell, the carrier frequency information is not separately signaled through SIB4, but SIB5 can specify the carrier frequency information about the adjacent cell to be measured.

[0139] In addition, the terminal 1e-01 in idle mode ("RRC_IDLE") finds a suitable cell and camps on its base station (1e-05), and connects to the base station (1e-15) due to reasons such as the presence of data to be sent. For example, in order to reduce the power consumption of the terminal, the terminal is not connected to the network in idle mode, so data cannot be sent. Therefore, the terminal needs to switch to RRC connection mode ("RRC_CONNECTED") to send data. In addition, "camping" can mean that the terminal stays in the cell and receives a paging message to determine whether data is sent in the downlink.

[0140] The access process of the terminal to the base station may represent a process of performing random access to the base station and the cell. That is, the terminal may send a terminal preamble (msg1) in step 1e-15, and the base station may send a random access response message (msg2) to the terminal in response to the preamble in step 1e-20.

[0141] In addition, in step 1e-25, the terminal may send an RRC connection request message (msg3) for requesting an RRC connection, which includes a terminal ID and at least one of a connection reason, and in step 1e-30, the base station may send a response message (msg4) to the RRC connection request to the terminal.

[0142] Upon receiving the RRC connection establishment message, the terminal may determine that permission to switch to the RRC connection state has been received from the base station, and may send an RRC connection establishment completion message to the base station in step 1e-40. In addition, the terminal switches to the RRC connection mode ("RRC_CONNECTED") (1e-35), so that the terminal in the connection mode can send data to / receive data from the base station.

[0143] In step 1e-45, the base station may send an RRC connection reconfiguration message including a measurement configuration to the terminal. The measurement configuration included in the message may include at least one of information about intra RAT / interRAT / inter-RAT neighboring cells that need to be measured, information about the type of signal that needs to be measured, and information about a method for reporting measurement values. In step 1e-50, the terminal may send an RRC connection reconfiguration complete message in response to the message. If, in the configured measurement configuration, the measurement result of a specific measurement object meets the measurement condition for reporting (1e-55), the terminal may report the measurement result to the base station according to the configured reporting method (1e-60).

[0144] In step 1e-65, the base station may identify the channel status of the neighboring cells based on the measurement results reported by the terminal in the above steps, thereby identifying the cells with good channel status.

[0145] In step 1e-70, the base station may configure carrier aggregation (CA) to the terminal for reasons such as increased terminal traffic, providing better services, etc., and the cell with the good channel state identified above may be configured as a secondary cell (SCell) for CA. The configuration is included in the RRC connection reconfiguration message and sent to the terminal, and upon receiving the message, the terminal may send a response message to the base station in step 1e-70. Thereafter, in step 1e-75, the base station sends a MAC CE for activating carrier aggregation of a specific cell, thereby activating CA.

[0146] Figure 1F The present invention is a diagram illustrating an overall operation in which a terminal measures neighbor cells and reports the measured cells to a base station in an idle state in an LTE system or an NR system according to the disclosure so as to quickly activate carrier aggregation after switching from the idle state to the RRC connected state.

[0147] Reselecting a cell is a process in which a terminal determines a cell to reside in when the service quality of the serving cell is lower than that of a neighboring cell due to the movement of the terminal in an idle state (or idle mode). The handover is determined by the network (MME or source eNB), while the cell reselection is determined by the terminal based on the measurement value. In addition, the cell reselected by the mobile terminal can be a cell using the same LTE frequency as the serving cell on which the terminal is currently camping (same-frequency cell), a cell using an LTE frequency different from the LTE frequency of the serving cell (inter-frequency cell), or a cell using another radio access technology (inter-RAT cell).

[0148] The terminal 1f-01 in the idle state performs a series of operations while residing on the serving cell (1f-05). First, the terminal can receive system information (SIB) (1f-10) broadcast by the base station 1f-02 of the serving cell. The configuration and quantity of system information may be different between the LTE system and the NR system. For example, information related to the measurement of adjacent cells in the same-frequency measurement can be sent through SIB4 in LTE, and information related to the measurement of adjacent cells in the same-frequency measurement can be sent through SIB3 in NR. In addition, information related to different-frequency measurements can be sent through SIB5 in LTE and can be sent through SIB4 in NR. The system information may include a threshold for determining whether to measure adjacent cell signals, parameters for calculating the ranks of serving cells and adjacent cells, and the like. In addition, for the same-frequency measurement, since the carrier frequency is the same as the current serving cell, the carrier frequency information is not separately signaled, but the carrier frequency information about the adjacent cell to be measured can be specified in the different-frequency measurement. The following description with reference to the accompanying drawings will be based on LTE, wherein LTE can be applied to NR without significantly changing its function.

[0149] The terminal may switch to the connected state 1f-15 depending on whether there is data to be sent or received about the resident serving cell, and if there is no data to be sent or received in the connected state, the terminal may switch to the idle state. The switching may be determined and indicated by the base station, and may be indicated by an RRC connection release message as described in step 1f-20.

[0150] Even in the idle state, the base station can instruct the terminal to measure neighboring cells, and the message may include a measurement configuration for measuring neighboring cells. In this case, the measurement configuration may provide frequency information in the form of a list for idle measurement. More specifically, the measurement configuration may include information about carrier frequency, bandwidth information, information about a valid cell list {physical cell index (PCI)} for measuring neighboring cells in idle mode, information about a cell list (PCI) to be measured, information about the type of reference signal to be measured, information about a threshold, and the like. At least one of the list of valid cells (valid area) for measuring neighboring cells may indicate a list of cells in which the terminal is able to perform idle mode measurements in the cell being camped, which may indicate that idle mode measurements can be processed in the corresponding cell. The parameters of the ASN.1 code below may be referred to, and for reference, the configuration for measuring NR cells may be obtained in a similar manner.

[0151]

[0152]

[0153]

[0154] As can be seen from the above RRC ASN.1 code, the configuration for measuring neighboring cells in the idle state can be sent through SIB (hereinafter, for example, "SIB5" will be described) or RRC release message. The difference between transmission using SIB5 and transmission using RRC release message is that SIB5 only provides inter-carrier frequency information (list) to be measured, and the RRC release message may include inter-carrier frequency information (list) to be measured and the duration of the timer indicating the time to perform the measurement in the idle mode ("measidleDuration-r15").

[0155] Basically, the RRC release message can be specifically used to instruct the terminal to perform idle mode measurement and trigger the operation, and SIB5 can provide a corresponding configuration so that the same configuration is applied to the corresponding serving cell. In the case where the inter-carrier frequency information is configured through SIB5, the base station can omit the configuration of the inter-carrier frequency information to be measured in the idle state for the RRC release message. If both SIB5 and the RRC release message include the inter-carrier frequency information to be measured in the idle state, the information included in the RRC release message may have priority.

[0156] In step 1f-20, upon receiving the RRC release message including information indicating measurement of neighboring cells in the idle state, the terminal starts measuring the configured frequency and cell in the idle state, and operates the idle state cell measurement timer T331 in step 1f-25. Thereafter, the timer T331 operates, and the terminal performs cell measurement in the idle state for the duration of the timer ("measidleDuration-r15"). If the timer expires, the terminal stores the last measurement value of the configured neighboring cell in its buffer.

[0157] If the terminal switches to the RRC connected state during the operation of timer T331 before the expiration of timer T331 (for example, if the terminal performs a random access procedure to the serving cell in steps 1f-30 to 1f-45 and switches to the RRC connected state in step 1f-50), the terminal stops timer T331 and identifies whether the serving cell is capable of receiving idle mode measurement values ​​and quickly processing them as CA.

[0158] Whether the serving cell is capable of receiving idle mode measurement values ​​and quickly processing them as CA can be indicated by the field "idleModeMeasurements" in SIB2. Therefore, the terminal can determine whether to report the presence of measurement values ​​in idle mode based on the indication of "idleModeMeasurements" in SIB2. If it is determined that the serving cell in a connected state with the terminal is capable of receiving idle mode measurement values ​​and quickly processing them as CA, then in step 1f-55, the terminal sends an RRC connection establishment complete message to the serving cell, and the RRC connection establishment complete message includes an indicator indicating that the terminal stores the measurement values ​​of neighboring cells measured in the idle state.

[0159]

[0160] The serving cell receiving the message may recognize that there are measurement values ​​of neighboring cells measured by the terminal in the idle state, and may send a UE information request message requesting measurement value information to the terminal in step 1f-60.

[0161]

[0162] In step 1f-65, the terminal receiving the message may report the channel measurement value to the base station by sending a UE information response message including the channel measurement values ​​of the serving cell and the neighboring cell stored by the terminal.

[0163]

[0164]

[0165]

[0166] As can be seen from the above ASN.1 code, the UE information response message may include a channel measurement value (RSRP or RSRP) of the serving cell and a measurement value indicating a neighboring cell to be measured. More specifically, the UE information response message may include at least one of frequency information about the neighboring cell, a PCI ID, and a channel measurement value (RSRP or RSRP) of the corresponding cell. For reference, the current LTE limits the number of frequencies to be measured in the idle state to three, and limits the maximum number of cells that can be measured for each frequency to eight.

[0167] Upon receiving the measurement value of the neighboring cell in the idle state from the terminal, the base station may provide the terminal with the SCell configuration information of CA in step 1f-70. The base station may refer to the content reported by the terminal in this step, and may activate CA by sending an activation MAC CE for SCell for reasons such as an increase in the amount of data sent by the terminal in subsequent steps.

[0168] In this disclosure Figure 1E and Figure 1F The difference between the method of activating CA in the existing LTE system and the process of activating CA using the measurement value of the neighboring cell measured in the idle state is shown. Since the process of configuring the measurement of the neighboring cell and measuring the neighboring cell can be omitted in the connected state, the terminal can switch to the connected state and perform fast configuration of CA.

[0169] Figure 1G is a diagram illustrating a conventional idle mode measurement operation of a terminal when reselecting a cell according to the disclosure.

[0170] The terminal 1g-05 that sends / receives data in a connected state in the serving cell 1 (1g-01) may receive an RRC connection release message (or an RRC release message) 1g-10 for reasons such as interruption of data transmission / reception, thereby switching to an idle mode. The corresponding base station may instruct the terminal to switch to an idle state, while instructing the terminal to perform channel measurement of a neighboring cell even in the idle mode. Information for measuring neighboring cells in the idle mode (e.g., at least one of a measurement frequency, a cell list, and a duration of a timer T331) may be included in the RRC release message 1g-10.

[0171] Thereafter, the terminal may move and wait in an idle state, and may move to cell 2 (1g-02) and cell 3 (1g-03) in an idle state. The terminal may camp on cell 3 (1g-03), and may attempt to connect to a corresponding serving cell such as cell 4 1g-04. The terminal performs measurements based on the idle mode measurement list previously received through the RRC release message 1g-10. If the SIB2 of cell 3 (1g-03) has an indicator indicating that an idle mode measurement value can be processed, the terminal may perform measurements in an idle state after connection, and may report stored measurement values.

[0172] If the RRC release message 1g-10 includes only the duration of the timer T331 and does not include information about the idle mode measurement frequency / cell in step 1g-10, the terminal can reselect cell 3 (1g-03) and can then receive system information (obtain SIB2 and SIB5 information) from the corresponding cell {cell 3 (1g-03)} in step 1g-20, thereby storing information about the idle mode measurement frequency / cell. However, in the above operation, the terminal also receives information about the idle mode measurement frequency / cell through the system information of the previous serving cell {cell 1 (1g-01)}, and after the cell reselection, the terminal can receive and store new information related thereto through cell 3 (1g-03). The current LTE standard stipulates that both pieces of information are stored and the terminal performs an operation of measuring adjacent cells in idle mode. However, in the case where the measurement frequency / cell lists provided by the two serving cells are different from each other, the terminal measures a greater number of frequencies and cells, which complicates the operation of the terminal. In addition, since the current standard allows measurement of up to three measurement frequencies and up to eight cells per frequency, the required operation may not be performed correctly.

[0173] That is, if the RRC release message 1g-10 includes only the duration of the timer T331 and does not include information about the idle mode measurement frequency / cell, the terminal reselects cell 3 (1g-03), and then replaces (or updates) the information about the idle mode measurement frequency / cell received and stored through SIB5 in the existing service cell with the information received through SIB5 in the new service cell 3 (1g-03). As described above, the above operation can be applied to LTE and NR in the same manner, and the inter-frequency information can be provided through SIB4 in NR instead of SIB5. In addition, in NR, the information about the idle mode measurement frequency / cell can include new parameters such as subcarrier spacing information and characteristics of the NR system.

[0174] Figure 1H is a diagram illustrating a method in which a terminal updates idle mode measurement information when a cell is reselected according to Embodiment 1 of an operation of a terminal proposed in the disclosure.

[0175] This example is based on reference Figure 1F and Figure 1G The overall operation of the terminal is described, and operations of the terminal and the base station are proposed in the case where the terminal switches to the idle mode through the RRC release message and then performs idle mode measurement and the terminal reselects a cell.

[0176] The terminal can reside on the serving cell (cell 1) in step 1h-05, and then can establish an RRC connection with the corresponding cell in step 1h-10 to send / receive data. The terminal (1h-10) that sends / receives data in the connected state can receive an RRC connection release message due to reasons such as interruption of data transmission / reception, thereby switching to idle mode (1h-15).

[0177] The base station / serving cell (cell 1) can instruct the terminal to switch to an idle state, and at the same time instruct the terminal to perform channel measurement (inter-frequency measurement) on a neighboring cell even in idle mode. Configuration information for channel measurement in idle mode (e.g., at least one of the measurement frequency, cell list, and duration of timer T331) may be included in the RRC release message. The RRC release message may include only the duration of timer T331, excluding information about the idle mode measurement frequency / cell. In this case, the base station may include information about the idle mode measurement frequency / cell in SIB5 (SIB4 in the case of NR), and then may send the information to the terminal, and the terminal may store and use the information.

[0178] The terminal may perform channel measurement on the configured frequency and cell in idle mode before the timer T331 expires.

[0179] In steps 1h-20, the terminal may perform an operation of reselecting a serving cell {eg, reselecting a specific serving cell (cell 2)} due to reasons such as movement of the terminal, change in channel status, etc.

[0180] When the terminal reselects a cell, the idle mode channel measurement operation of the terminal may be different depending on a previously received message indicating an idle mode measurement configuration.

[0181] In step 1h-25, the terminal may perform different operations depending on the received message indicating the idle mode measurement configuration.

[0182] If the terminal is provided with both a list of frequencies / cells to be measured in idle mode and the duration of timer T331 through the RRC release message, the terminal can perform an idle mode measurement operation through application information (configuration) in step 1h-30. If timer T331 expires during the measurement operation, the terminal can record the most recently measured neighboring frequency / cell measurement information.

[0183] Afterwards, if the terminal performs a connection process with the corresponding serving cell (cell 2) in step 1h-35 and receives msg4 (RRC connection establishment message), the terminal can identify whether the serving cell (cell 2) supports the processing of idle mode measurement values ​​and the rapid configuration and activation of CA through system information (SIB2). If the indicator indicates that the base station supports the operation, the terminal can include an indicator indicating the presence of idle mode measurement values ​​in msg5 (RRC connection establishment completion message) and can send the indicator. Thereafter, the terminal and the base station perform a process for reporting idle mode measurement values ​​in step 1h-40, which is based on Figure 1F The operations in steps 1f-55 to 1f-70 are performed.

[0184] At the same time, if the terminal only receives the duration of timer T331 through the RRC release message in step 1h-25, and if the terminal receives the list of frequencies / cells to be measured in idle mode and their configuration information through the system information of the previous serving cell (cell 1), the terminal can receive the system information (SIB5 in LTE and SIB4 in NR) again through the new serving cell (cell 2), and can update / replace the list of frequencies / cells to be measured in idle mode and their configuration information, which is received through the system information of the previous serving cell (cell 1) using the information received through the system information of the new serving cell (cell 2) in step 1h-45.

[0185] According to the current LTE standard, both the information received through the system information of cell 1 and the information received through the system information of cell 2 are stored, and then the terminal performs an operation of measuring neighboring cells in idle mode. However, if the measurement frequency / cell lists provided by the two serving cells are different from each other, the terminal measures a greater number of frequencies and cells, which complicates the operation of the terminal. In addition, since the current standard allows measurement of up to three measurement frequencies and up to eight cells per frequency, the required operation may not be performed correctly.

[0186] If the timer T331 is still operating in step 1h-50, the terminal can perform the operation of measuring the neighboring frequency / cell in the idle mode based on the latest updated / replaced idle mode measurement configuration. If the timer T331 expires during operation, the terminal can record the most recently measured neighboring frequency / cell measurement information.

[0187] If the terminal performs a connection process with the corresponding serving cell (cell 2) in step 1h-55 and receives msg4 (RRC connection establishment message), the terminal can identify whether the serving cell (cell 2) supports the processing of idle mode measurement values ​​and the rapid configuration and activation of CA through system information (SIB2). If the indicator indicates that the base station supports the operation, the terminal can include an indicator indicating the existence of idle mode measurement values ​​in msg5 (RRC connection establishment completion message) and can send the indicator. Thereafter, the terminal and the base station perform a process for reporting idle mode measurement values ​​in step 1h-60, which is based on Figure 1F The operations in steps 1f-55 to 1f-70 are performed.

[0188] Fig. 1I is a diagram illustrating a method of performing measurement in an idle mode based on frequency information of a base station supporting an enhanced CA function according to Embodiment 2 of an operation of a terminal proposed in the disclosure.

[0189] This example is based on reference Figure 1F and Figure 1G The overall operation of the terminal is described, and operations of the terminal and the base station are proposed in the case where the terminal switches to the idle mode through the RRC release message and then performs idle mode measurement and the terminal reselects a cell.

[0190] The terminal can camp on the serving cell (cell 1) in step 1i-05, and then can establish an RRC connection with the corresponding cell in step 1i-10 to send / receive data. The terminal (1i-10) that sends / receives data in the connected state can receive an RRC connection release message for reasons such as interruption of data transmission / reception, thereby switching to an idle mode (1i-15).

[0191] The base station / serving cell (cell 1) can instruct the terminal to switch to an idle state, and at the same time instruct the terminal to perform channel measurement (inter-frequency measurement) on adjacent cells even in idle mode. Configuration information for channel measurement in idle mode (e.g., at least one of the measurement frequency, cell list, and duration of timer T331) may be included in the RRC release message. The RRC release message may include only the duration of the timer, without including information about the idle mode measurement frequency / cell. In this case, the base station may include information about the idle mode measurement frequency / cell in SIB5 (SIB4 in the case of NR), and then may send the information to the terminal, and the terminal may store and use the information. In this embodiment, the RRC release message includes information about a frequency list to be measured by the terminal in idle mode.

[0192] like Figure 1F The configuration information for the existing measurement operation in idle mode, that is, the information included when the base station instructs the terminal to measure the neighboring cells even in the idle state, can be provided as frequency information in the form of a list that needs to be measured in the idle mode. More specifically, the information may include at least one of information about the carrier frequency to be measured, bandwidth information, information about a valid cell list {physical cell index (PCI)} for measuring neighboring cells in idle mode, information about a cell list (PCI) to be measured, information about the type of reference signal to be measured, information about a threshold, etc. The valid cell list (valid area) for measuring neighboring cells may indicate a cell list in which the terminal can perform idle mode measurement in the cell being camped, which may indicate that the idle mode measurement can be processed in the corresponding cell.

[0193] However, with reference to the frequency / cell configuration for conventional idle mode measurement, there is no indicator for determining whether the serving cell camped by the terminal can perform idle mode measurement at the frequency level. For example, the terminal may receive an instruction for a specific cell as a measurement object cell with different frequency information and the same PCI. In this case, it is difficult to determine the cell that supports the idle mode measurement operation in the current standard operation. Therefore, this embodiment proposes the following two methods to distinguish the above-mentioned cells.

[0194] - Idle Mode Measurement Support Indication Method 1: The terminal identifies whether the corresponding serving cell is supported through the idle mode measurement support indicator (1-bit "idleModeMeasurements" indicator) of the system information (eg SIB2) broadcast by the serving cell where the terminal is camped or reselected.

[0195] - Idle mode measurement support indication method 2: When idle mode measurement is indicated through the RRC release message, the base station provides valid frequency information ("ValidityFrequency") supporting idle mode measurement operation together with valid cell information ("ValidityArea"). NR frequency information can be provided separately. That is, "measidleCarrierListEUTRA" and "measidleCarrierListNR" are provided separately, and corresponding configuration parameters are provided.

[0196] ■ Signaling Method 1: It independently provides "ValidityFrequency" and "ValidityArea" as separate parameters.

[0197] ■Signaling method 2: Signaling is performed by associating a frequency with cell information (valid cell information for each frequency).

[0198] After step 1i-15, the terminal may perform channel measurement on the configured frequency and cell in idle mode before timer T331 expires. In the case of performing an operation of reselecting a specific serving cell (cell 2) in step 1i-20 for reasons such as terminal movement, change in channel state, etc., the terminal may perform different operations depending on whether idle mode measurement is supported in the serving cell (cell 2).

[0199] Therefore, in step 1i-25, the terminal can identify whether the serving cell supports idle mode measurement, and can perform different operations. If the serving cell (cell 2) reselected by the terminal supports idle mode measurement, the terminal performs the idle mode measurement operation by applying information (configuration) in step 1i-30. The method of identifying whether idle mode measurement is supported may include at least one of the idle mode measurement support indication method 1 and the idle mode measurement support indication method 2 described in the embodiment. If the timer T331 expires during the corresponding operation, the terminal may record the most recently measured adjacent frequency / cell measurement information.

[0200] If the terminal performs a connection process with the corresponding serving cell (cell 2) in step 1i-35 and receives msg4 (RRC connection establishment message), the terminal can identify whether the serving cell (cell 2) supports the processing of idle mode measurement values ​​and the rapid configuration and activation of CA through system information (SIB2). If the indicator indicates that the base station supports the operation, the terminal can include an indicator indicating the presence of idle mode measurement values ​​in msg5 (RRC connection establishment completion message) and can send the indicator. Thereafter, the terminal and the base station perform a process for reporting idle mode measurement values ​​in step 1i-40, which is based on Figure 1F The operations in steps 1f-55 to 1f-70 are performed.

[0201] Meanwhile, if the serving cell (cell 2) reselected by the terminal in 1i-25 does not support idle mode measurement, the terminal stops the operation of timer T331, thereby stopping idle mode measurement in step 1i-45. The method of identifying whether idle mode measurement is supported may include at least one of idle mode measurement support indication method 1 and idle mode measurement support indication method 2 described in the embodiment.

[0202] In addition, the difference between the disclosed and existing terminal operations is that: if the terminal checks the frequency / cell of the serving cell (cell 2) after cell reselection and identifies that the corresponding cell does not support idle mode measurement, the terminal stops the idle mode measurement. That is, according to the existing operation, even if the terminal reselects the serving cell, the terminal continues to perform the idle mode measurement, while in the disclosed method, if the serving cell does not perform the idle mode measurement, the measurement is stopped.

[0203] The terminal may perform a process of connecting to the serving cell (cell 2), and then know in step 1i-50 that the serving cell (cell 2) does not support idle mode measurement. Therefore, the terminal may omit the process of reporting idle mode measurement, and may perform a process according to existing LTE and NR in step 1i-55.

[0204] According to the operation proposed in the embodiment, the terminal knows whether the corresponding serving cell supports idle mode measurement by pre-receiving or identifying the valid frequency and valid cell configuration, and if it is identified that the corresponding serving cell does not support idle mode measurement, the terminal stops the idle mode measurement operation. Alternatively, the terminal can maintain the previous operation of the terminal (even if the corresponding serving cell does not support idle mode measurement, the terminal continues to perform idle mode measurement, identifies the indicator of SIB2 of the serving cell, and omits the process of reporting idle mode measurement).

[0205] In addition, the base station can independently manage the idle mode measurement and idle mode measurement report of the terminal by the following method. This method can be used in the case of mixed base stations, so that a specific base station does not upgrade support for operations related to idle mode measurement, and only some other base stations support the operations.

[0206] 1. If the serving cell does not provide the idle mode measurement related configuration as system information, the terminal maintains the idle mode measurement related configuration in the system information (or RRC release) received from the previous serving cell.

[0207] 2. If the cell provides system information including blank idle mode measurement related configuration (i.e., if the cell broadcasts idle mode measurement related configuration that does not include frequency / cell related configuration), the terminal recognizes that the cell does not support idle mode measurement, thereby stopping timer T331 and stopping the idle mode measurement operation.

[0208] Figure 1J is a block diagram illustrating an internal structure of a terminal according to the disclosure.

[0209] refer to Figure 1J The terminal includes a radio frequency (RF) processor 1j-10, a baseband processor 1j-20, a storage unit 1j-30 and a controller 1j-40.

[0210] The RF processor 1j-10 performs functions of sending and receiving signals through a radio channel, such as frequency band conversion and signal amplification. That is, the RF processor 1j-10 up-converts the baseband signal provided by the baseband processor 1j-20 into an RF band signal, thereby transmitting the RF band signal through an antenna, and down-converts the RF band signal received through the antenna into a baseband signal. For example, the RF processor 1j-10 may include a transmitting filter, a receiving filter, an amplifier, a mixer, an oscillator, a digital-to-analog converter (DAC), an analog-to-digital converter (ADC), etc. Although in Figure 1J Only one antenna is shown in the figure, but the terminal can have multiple antennas. In addition, the RF processor 1j-10 may include multiple RF chains. In addition, the RF processor 1j-10 can perform beamforming. In order to perform beamforming, the RF processor 1j-10 can adjust the phase and amplitude of the signal sent and received through multiple antennas or antenna elements. In addition, the RF processor can perform MIMO and can receive multiple layers when performing MIMO operation.

[0211] The baseband processor 1j-20 performs the conversion function between the baseband signal and the bit string according to the physical layer specification of the system. For example, when sending data, the baseband processor 1j-20 encodes and modulates the transmitted bit string to generate complex symbols. In addition, when receiving data, the baseband processor 1j-20 demodulates and decodes the baseband signal provided from the RF processor 1j-10 to recover the received bit string. For example, in the case of applying the orthogonal frequency division multiplexing (OFDM) scheme, when sending data, the baseband processor 1j-20 generates complex symbols by encoding and modulating the transmitted bit string, maps the complex symbols to subcarriers, and then configures OFDM symbols through inverse fast Fourier transform (IFFT) operations and cyclic prefix (CP) insertion. In addition, when receiving data, the baseband processor 1j-20 divides the baseband signal provided by the RF processor 1j-10 into OFDM symbol units, recovers the signal mapped to the subcarrier through a fast Fourier transform (FFT) operation, and then recovers the received bit string through demodulation and decoding.

[0212] The baseband processor 1j-20 and the RF processor 1j-10 send and receive signals as described above. Therefore, the baseband processor 1j-20 and the RF processor 1j-10 can be referred to as a "transmitter", "receiver", "transceiver" or "transceiver". In addition, at least one of the baseband processor 1j-20 and the RF processor 1j-10 may include multiple communication modules to support multiple different radio access technologies. In addition, at least one of the baseband processor 1j-20 and the RF processor 1j-10 may include different communication modules to process signals in different frequency bands. For example, different radio access technologies may include wireless LAN (e.g., IEEE802.11), cellular networks (e.g., LTE), etc. In addition, different frequency bands may include ultra-high frequency (SHF) (e.g., 2.NRHz or NRHz) bands or millimeter wave (e.g., 60GHz) bands.

[0213] The storage unit 1j-30 stores data such as basic programs, application programs, and configuration information for terminal operation. Specifically, the storage unit 1j-30 can store information related to a second access node that performs wireless communication using a second radio access technology. In addition, the storage unit 1j-30 provides the stored data in response to a request from the control unit 1j-40.

[0214] The controller 1j-40 controls the overall operation of the terminal. For example, the controller 1j-40 sends and receives signals through the baseband processor 1j-20 and the RF processor 1j-10. In addition, the controller 1j-40 records data in the storage unit 1j-30 and reads data from the storage unit 1j-30. To this end, the controller 1j-40 may include at least one multi-connection processor 1j-42. For example, the controller 1j-40 may include a communication processor (CP) for controlling communications and an application processor (AP) for controlling high layers such as applications.

[0215] Figure 1K is a block diagram illustrating a configuration of a base station according to the disclosure.

[0216] like Figure 1K As shown, the base station includes an RF processor 1k-10, a baseband processor 1k-20, a backhaul transceiver 1k-30, a storage unit 1k-40 and a controller 1k-50.

[0217] The RF processor 1k-10 performs functions such as frequency band conversion and signal amplification for sending and receiving signals through a radio channel. That is, the RF processor 1k-10 up-converts the baseband signal provided by the baseband processor 1k-20 into an RF band signal, thereby sending the RF band signal through an antenna, and down-converts the RF band signal received by the antenna into a baseband signal. For example, the RF processor 1k-10 may include a transmit filter, a receive filter, an amplifier, a mixer, an oscillator, a DAC, an ADC, and the like. Although only one antenna is shown in the figure, the first access node may have multiple antennas. In addition, the RF processor 1k-10 may include multiple RF chains. In addition, the RF processor 1k-10 may perform beamforming. In order to perform beamforming, the RF processor 1k-10 may adjust the phase and amplitude of the signal sent and received through multiple antennas or antenna elements. The RF processor may perform downlink MIMO operations by sending one or more layers.

[0218] The baseband processor 1k-20 performs a conversion function between a baseband signal and a bit string according to the physical layer specification of the first radio access technology. For example, when sending data, the baseband processor 1k-20 encodes and modulates the transmission bit string to generate a complex symbol. In addition, when receiving data, the baseband processor 1k-20 demodulates and decodes the baseband signal provided from the RF processor 1k-10 to recover the received bit string. For example, in the case of applying the OFDM scheme, when sending data, the baseband processor 1k-20 generates a complex symbol by encoding and modulating the transmission bit string, maps the complex symbol to a subcarrier, and then configures the OFDM symbol through an IFFT operation and CP insertion. In addition, when receiving data, the baseband processor 1k-20 divides the baseband signal provided by the RF processor 1k-10 into OFDM symbol units, recovers the signal mapped to the subcarrier through an FFT operation, and then recovers the received bit string through demodulation and decoding. The baseband processor 1k-20 and the RF processor 1k-10 send and receive signals as described above. Therefore, the baseband processor 1k-20 and the RF processor 1k-10 can be referred to as a "transmitter", "receiver", "transceiver", "transceiver" or "wireless transceiver".

[0219] The backhaul transceiver 1k-30 provides an interface for performing communication with other nodes in the network. That is, the backhaul transceiver 1k-30 converts a bit string sent from the main base station to another node such as a secondary base station, a core network, etc. into a physical signal, and converts a physical signal received from other nodes into a bit string.

[0220] The storage unit 1k-40 stores data such as basic programs, application programs, and configuration information for the operation of the base station. Specifically, the storage unit 1k-40 may store information about the bearer assigned to the connected terminal, measurement results reported from the connected terminal, etc. In addition, the storage unit 1k-40 may store information as a criterion for determining whether to provide multiple connections to the terminal or release multiple connections. In addition, the storage unit 1k-40 provides the stored data in response to a request from the controller 1k-50.

[0221] The controller 1k-50 controls the overall operation of the base station. For example, the controller 1k-50 sends and receives signals through the baseband processor 1k-20 and the RF processor 1k-10 or the backhaul transceiver 1k-30. In addition, the controller 1k-50 records data in the storage unit 1k-40 and reads data from the storage unit 1k-40. To this end, the controller 1k-50 may include at least one multi-connection processor 1k-52.

[0222] Figure 2A is a diagram illustrating a structure of an LTE system according to an embodiment.

[0223] refer to Figure 2A The radio access network of the LTE system includes evolved Node Bs (hereinafter referred to as "ENBs", "Node Bs" or "base stations") 2a-05, 2a-10, 2a-15 and 2a-20, a mobility management entity (MME) 2a-25 and a serving gateway (S-GW) 2a-30. User equipment (hereinafter referred to as "UE" or "terminal") 2a-35 accesses an external network through ENBs 2a-05 to 2a-20 and S-GW 2a-30.

[0224] exist Figure 2A In the LTE system, ENB 2a-05 or 2a-20 may correspond to an existing Node B of a Universal Mobile Telecommunications System (UMTS). ENB may be connected to UE 2a-35 via a radio channel and may play a more complex role than an existing Node B. In an LTE system, all user traffic including real-time services such as Voice over IP (VoIP) over Internet Protocol may be provided with services through a shared channel. Therefore, a device for collecting status information such as a buffer status of a UE, an available transmission power status, and a channel status and performing scheduling is required. ENB 2a-05 to 2a-20 serve as such a device.

[0225] One ENB usually controls multiple cells. For example, in order to achieve a data rate of 100Mbps, the LTE system uses orthogonal frequency division multiplexing (OFDM) as a radio access technology in, for example, a 20MHz bandwidth. In addition, an adaptive modulation and coding (AMC) scheme is applied to determine the modulation scheme and channel coding rate according to the channel state of the terminal. The S-GW 2a-30 is a device for providing data bearers, and can generate or remove data bearers under the control of the MME 2a-25. The MME is a device that performs various control functions and a mobility management function of the terminal, and can be connected to multiple base stations.

[0226] Figure 2B is a diagram illustrating a radio protocol structure in an LTE system according to an embodiment.

[0227] refer to Figure 2B , the radio protocol of the LTE system includes Packet Data Convergence Protocol (PDCP) 2b-05 or 2b-40, Radio Link Control (RLC) 2b-10 or 2b-35, and Medium Access Control (MAC) 2b-15 or 2b-30 in the terminal and ENB, respectively. PDCP performs operations such as IP header compression / decompression. The main functions of PDCP are summarized as follows.

[0228] -Header compression and decompression (ROHC only)

[0229] -Transmission of user data

[0230] - For RLC AM, in-sequence delivery of higher layer PDUs during PDCP re-establishment

[0231] - Sequence reordering {For split bearer in DC (supports RLC AM only): PDCP PDU routing for transmission and PDCP PDU reordering for reception}

[0232] - For RLC AM, repeat detection of lower layer SDUs during PDCP re-establishment

[0233] - For RLC AM, retransmit PDCP SDUs at handover, and for split bearers in DC, retransmit PDCP PDUs during PDCP data recovery

[0234] -Encryption and decryption

[0235] - Timer based SDU discard in uplink.

[0236] Radio Link Control (RLC) 2b-10 or 2b-35 reconfigures a PDCP Packet Data Unit (PDU) into an appropriate size and performs an ARQ operation, etc. The main functions of the RLC are summarized as follows.

[0237] -Data transmission function (transmission of high-level PDU)

[0238] -ARQ function {Error correction through ARQ (only for AM data transmission)}

[0239] -RLC SDU concatenation, segmentation and reassembly (only for UM and AM data transmission)

[0240] - Re-segmentation of RLC data PDU (only for AM data transmission)

[0241] - Reordering of RLC data PDUs (only for UM and AM data transmission)

[0242] - Duplicate detection (for UM and AM data transmission only)

[0243] -Protocol error detection (for AM data transmission only)

[0244] -RLC SDU discard (only for UM and AM data transmission)

[0245] -RLC reconstruction

[0246] MAC 2b-15 or 2b-30 is connected to multiple RLC entities configured in a single terminal, multiplexes RLC PDUs into MAC PDUs, and demultiplexes RLC PDUs from MAC PDUs. The main functions of MAC are summarized as follows.

[0247] - Mapping between logical channels and transport channels

[0248] - Multiplexing / demultiplexing MAC SDUs belonging to one or different logical channels to / from transport blocks (TBs) delivered to the physical layer on transport channels

[0249] -Dispatch information report

[0250] -HARQ function (error correction through HARQ)

[0251] - Priority handling between logical channels of a UE

[0252] - Priority handling between UEs through dynamic scheduling

[0253] -MBMS service logo

[0254] -Transmission format selection

[0255] -filling

[0256] The physical layers 2b-20 and 2b-25 channel-code and modulate the higher-layer data, convert it into OFDM symbols, and then send it through the radio channel, or demodulate and channel-decode the OFDM symbols received through the radio channel, and then send it to the higher layer.

[0257] Figure 2C is a diagram illustrating a structure of a next-generation mobile communication system according to an embodiment.

[0258] refer to Figure 2C , the radio access network of the next generation mobile communication system (hereinafter referred to as "NR" or "5G") includes a new radio node B (hereinafter referred to as "NR gNB" or "NR base station") 2c-10 and a new radio core network (NR CN) 2c-05. The new radio user equipment ("NRUE" or "terminal") 2c-15 accesses the external network through the NR gNB 2c-10 and the NR CN 2c-05.

[0259] exist Figure 2C In the present invention, the NR gNB 2c-10 may correspond to the evolved Node B (eNB) in the existing LTE system. The NR gNB is connected to the NR UE 2c-15 via a radio channel and may provide services superior to those of the existing Node B. In the next generation mobile communication system, all user traffic is served through a shared channel. Therefore, a device is required for collecting status information such as the buffer status, available transmit power status, and channel status of the UE and performing scheduling. The NR gNB 2c-10 is used as such a device. One NR gNB may control multiple cells. In order to achieve an ultra-high data rate compared to the existing LTE system, the next generation mobile communication system may have a bandwidth equal to or greater than the maximum bandwidth of the existing system. In addition, the next generation mobile communication system may use orthogonal frequency division multiplexing (OFDM) as a radio access technology, and may adopt beamforming technology in addition to this.

[0260] In addition, an adaptive modulation and coding (hereinafter, referred to as 'AMC') scheme may be applied to determine a modulation scheme and a channel coding rate according to a channel state of a terminal.

[0261] NR CN 2c-05 performs functions such as mobility support, bearer configuration, and QoS configuration. NR CN is a device that performs various control functions as well as mobility management functions of the terminal, and can be connected to multiple base stations. In addition, the next-generation mobile communication system can interoperate with the existing LTE system, and NR CN can be connected to MME 2c-25 through a network interface. MME can be connected to eNB 2c-30, which is an existing base station in the network 2c-20 with NR gNB 2c-10.

[0262] Figure 2D is a diagram illustrating a radio protocol structure of a next-generation mobile communication system according to an embodiment.

[0263] refer to Figure 2D The radio protocols of the next-generation mobile communication system include NR Service Data Adaptation Protocol (SDAP) 2d-01 or 2d-45, NR PDCP 2d-05 or 2d-40, NR RLC 2d-10 or 2d-35, NRMAC 2d-15 or 2d-30 and NR PHY 2d-20 or 2d-25 in the terminal and NR base station, respectively.

[0264] The main functions of NR SD AP 2d-01 or 2d-45 may include some of the following functions.

[0265] -Transmission of user plane data

[0266] - Mapping between QoS flows and DRBs for downlink and uplink

[0267] - Marking of QoS flow ID in both downlink and uplink packets

[0268] - Mapping of Reflective QoS Flows to DRBs for UL SDAP PDUs

[0269] Regarding the SDAP layer entity, the terminal may receive a header indicating whether to use the SDAP layer entity or a configuration of the function of the SDAP layer entity for each PDCP layer entity, for each bearer, or for each logical channel through a radio resource control (RRC) message. When the SDAP header is configured, a 1-bit non-access stratum (NAS) reflection quality of service (QoS) configuration indicator and a 1-bit access stratum (AS) reflection QoS configuration indicator of the SDAP header may indicate that the terminal updates or reconfigures the mapping information between the QoS flow and the data bearers in the uplink and downlink. The SDAP header may include QoS flow ID information indicating QoS. QoS information may be used as data processing priority, scheduling information, etc., in order to support effective services.

[0270] The main functions of NR PDCP 2d-05 or 2d-40 may include some of the following functions.

[0271] -Header compression and decompression (ROHC only)

[0272] -Transmission of user data

[0273] - In-sequence delivery of higher-level PDUs

[0274] - Out-of-order delivery of higher-level PDUs

[0275] -Sequence reordering (for received PDCP PDU reordering)

[0276] - Duplicate detection of lower layer SDUs

[0277] -Retransmission of PDCP SDU

[0278] -Encryption and decryption

[0279] - Timer-based SDU discard in uplink

[0280] The above-mentioned reordering function of the NR PDCP entity may refer to a function of reordering the PDCP PDU received from the lower layer based on the PDCP sequence number (SN). The reordering function of the NR PDCP entity may include a function of sending data to the upper layer in a reordered order, a function of directly sending data to the upper layer without considering its order, a function of reordering the sequence and recording the lost PDCP PDU, a function of sending a status report of the lost PDCP PDU to the transmitting end, and a function of requesting retransmission of the lost PDCP PDU.

[0281] The main functions of NR RLC 2d-10 or 2d-35 may include some of the following functions.

[0282] -Data transmission function (transmission of high-level PDU)

[0283] - In-sequence delivery of higher-level PDUs

[0284] - Out-of-order delivery of higher-level PDUs

[0285] -ARQ function (error correction through ARQ)

[0286] - Concatenation, segmentation and reassembly of RLC SDU

[0287] - Re-segmentation of RLC data PDUs

[0288] - Reordering of RLC data PDUs

[0289] - Duplicate detection

[0290] -Protocol error detection

[0291] -RLC SDU discarded

[0292] -RLC reconstruction

[0293] The above-mentioned in-sequence delivery function of the NR RLC entity may refer to a function of delivering the RLC SDU received from the lower layer to the higher layer in sequence. The in-sequence delivery function of the NR RLC entity may include a function of reassembling and sending the original RLC SDU if the original RLC SDU is divided into multiple RLC SDUs and received.

[0294] The in-sequence delivery function of the NR RLC entity may include the function of reordering the received RLC PDU based on the RLC sequence number (SN) or the PDCP sequence number (SN), the function of reordering the sequence and recording the lost RLC PDU, the function of sending a status report of the lost RLC PDU to the transmitter, and the function of requesting retransmission of the lost RLC PDU.

[0295] The in-sequence delivery function of the NR RLC entity 2d-10 or 2d-35 may include a function of sending only the RLC SDUs before the lost RLC SDUs to the higher layer in sequence if there is a lost RLC SDU. In addition, the in-sequence delivery function of the NR RLC entity may include a function of sending all RLC SDUs received before the timer starts to the higher layer in sequence if a predetermined timer expires even if there is a lost RLC SDU. In addition, the in-sequence delivery function of the NR RLC entity may include a function of sending all RLC SDUs received until that time point to the higher layer in sequence if a predetermined timer expires even if there is a lost RLC SDU.

[0296] In addition, the NR RLC entity 2d-10 or 2d-35 can process the RLC PDU in the order of receipt regardless of the sequence number (in an out-of-order delivery manner) and can send it to the NR PDCP entity 2d-05 or 2d-40.

[0297] In the case of receiving segments, the NR RLC entity 2d-10 or 2d-35 can receive the segments stored in the buffer or to be received later, can reconfigure it into a complete RLC PDU, and can send it to the NR PDCP.

[0298] The NR RLC layer may not include the cascading function, which may be performed in the NR MAC layer or may be replaced by the multiplexing function of the NR MAC layer.

[0299] In the above description, the out-of-order delivery of the NR RLC entity may mean a function of directly delivering the RLC SDU received from the lower layer to the higher layer regardless of the order thereof. The out-of-order delivery of the NR RLC entity may include a function of reassembling and delivering an original RLC SDU if the original RLC SDU is divided into a plurality of RLC SDUs and received. The out-of-order delivery of the NR RLC entity may include a function of storing and sorting the RLC SN or PDCP SN of the received RLC PDU, thereby recording the lost RLC PDU.

[0300] NR MAC 2d-15 or 2d-30 can be connected to multiple NR RLC entities configured in a single terminal, and the main functions of NR MAC may include some of the following functions.

[0301] - Mapping between logical channels and transport channels

[0302] -Multiplexing / demultiplexing of MAC SDU

[0303] -Dispatch information report

[0304] -HARQ function (error correction through HARQ)

[0305] - Priority handling between logical channels of a UE

[0306] - Priority handling between UEs through dynamic scheduling

[0307] -MBMS service logo

[0308] -Transmission format selection

[0309] -filling

[0310] The NR PHY layers 2d-20 and 2d-25 may perform operations of channel encoding and modulating high-layer data into OFDM symbols and transmitting them through a radio channel, or of demodulating and channel decoding OFDM symbols received through a radio channel and transmitting them to a high layer.

[0311] Figure 2E 2 is a diagram illustrating a process in which a terminal that does not support idle mode measurement establishes an RRC connection with a base station and switches from the RRC idle mode to the RRC connected mode, and a process in which the base station configures carrier aggregation (hereinafter referred to as "CA") to the terminal according to an embodiment.

[0312] According to the embodiment, the terminal can perform frequency measurement in RRC idle mode to find a cell or a serving cell to reside in, thereby performing a cell selection process and / or a cell reselection process. However, the terminal measures several frequencies separately in RRC idle mode and does not report its measurement results to the base station. That is, after switching from RRC idle mode to RRC connected mode, the terminal can measure at least one frequency based on the measurement configuration (hereinafter referred to as "measConfig") configured by the base station through an RRC connection reconfiguration message ("RRCConnectionReconfiguration"), and if the configured conditions are met, the terminal can send a measurement report message ("MeasurementReport") to the base station.

[0313] refer to Figure 2E For some reason, the terminal 2e-01 may be in RRC idle mode (2e-03). The terminal may find a suitable cell and reside on it in RRC idle mode through a cell selection process and / or a cell reselection process, thereby receiving system information (2e-05).

[0314] Terminal 2e-01 can trigger random access to establish an RRC connection with base station 2e-02 (2e-06). When random access is triggered, the terminal can select a PRACH timing and can send a random access preamble to the base station (2e-10). Upon receiving the random access preamble, the base station can send a random access response (hereinafter referred to as "RAR") message to the terminal in response thereto (2e-15). Terminal 2e-01 in RRC idle mode can establish reverse link transmission synchronization with base station 2e-02 through steps 2e-10 and 2e-15.

[0315] The terminal 2e-01 in RRC idle mode that has established reverse link transmission synchronization can perform an RRC connection establishment process with the base station 2e-02. First, the terminal 2e-01 can send an RRC connection establishment request message ("RRCConnectionRequest") to the base station (2e-20). The message may include at least one of the terminal's identifier ("ue-Identity"), the reason for establishing the RRC connection ("establishmentCause"), etc.

[0316] If the RRC connection establishment request message is received, the base station may send an RRC connection establishment message ("RRCConnectionSetup") to the terminal (2e-25). The message may include radio resource configuration information ("RadioResourceConfigDedicated", "radioBearerConfig" or "masterCellGroup"). If the RRC connection establishment message is received, the terminal may identify the radio resource configuration information and may then switch to the RRC connection mode (2e-26). The RRC connection establishment may involve a connection of a signaling radio bearer 1 (SRB1). Therefore, an RRC message as a control message between the terminal and the base station, an RRC message including a NAS message, or an initial NAS message may be sent and received through SRB1.

[0317] The terminal that has switched to the RRC connection mode may send an RRC connection setup completion message ("RRCConnectionSetupComplete") to the base station via SRB1 (2e-30). The message may include a service request message for the terminal to request the AMF or MME for bearer configuration for a predetermined service.

[0318] If the RRC connection establishment process is successfully performed, the base station 2e-02 can perform an RRC connection reconfiguration process with the terminal 2e-01. First, the base station can send an RRC connection reconfiguration message ("RRCConnectionReconfiguration") to the terminal (2e-40). The message may include configuration information about a data radio bearer (DRB) for processing user data, configuration information about SRB1 and / or SRB2 through which control messages can be sent and received, or a measurement configuration ("measConfig"). Upon receiving the RRC connection reconfiguration message, the terminal can apply the above information, and can then send an RRC connection reconfiguration completion message ("RRCCoonectionReconfigurationComplete") to the base station (2e-45).

[0319] If the RRC connection reconfiguration message includes a measurement configuration ("measConfig") in step 2e-40, the terminal in RRC connection mode can perform measurement by applying the information, and if a measurement report is triggered (2e-46), the terminal can send a measurement report message ("MeasurementReport") to the base station (2e-50).

[0320] The base station 2e-02 that has successfully received the measurement report message can perform an RRC connection reconfiguration process to configure carrier aggregation for the terminal 2e-01 in RRC connection mode. Carrier aggregation according to an embodiment indicates a technology for sending / receiving a larger amount of data between a terminal and a base station through an additional carrier or SCells (secondary cell or service cell).

[0321] First, the base station may send an RRC connection reconfiguration message ("RRCConnectionReconfiguration") to the terminal (2e-55). The message may include configuration information about at least one SCell (SCell configuration). For example, the configuration information about the SCell may include at least one of information about a list of SCells to be added or modified as an information element (hereinafter referred to as "IE") ("sCellToAddModList"), and information about a list of connected SCells to be released ("sCellToReleaseList"). The terminal that has successfully received the RRC connection reconfiguration message may apply the configuration information about the SCell, and may then send an RRC connection reconfiguration completion message to the base station (2e-60). The base station may indicate the state (activated state or deactivated state) of each SCell configured to the terminal through a MAC control element (hereinafter referred to as "MAC CE") (2e-65), thereby applying carrier aggregation.

[0322] Figure 2F is a diagram illustrating a process in which a terminal supporting idle mode measurement releases an RRC connection with a base station and performs idle mode measurement according to an embodiment, and the base station configures carrier aggregation (CA) to the terminal based on the idle mode measurement result.

[0323] The terminal according to the embodiment can perform frequency measurement in RRC idle mode to find a cell or serving cell to camp on, thereby performing a cell selection process and / or a cell reselection process. In addition, the terminal measures several frequencies separately in RRC idle mode and can store its measurement results.

[0324] Specifically, the base station may signal the terminal through an RRC connection release message ("RRCConnectionRelease") or system information (e.g., SIB5 or new SIBx) a measurement configuration ("measidleConfig") available in the RRC idle mode. Therefore, the terminal may measure at least one frequency based on the measurement configuration available in the RRC idle mode, and if the configured condition is met, the terminal may switch to the RRC connected mode, thereby reporting a measurement report message ("MeasurementReport") to the base station.

[0325] Alternatively, in the case where the base station sends a UE information request message ("UEInformationRequest") to a terminal that has switched from RRC idle mode to RRC connected mode in order to request a measurement result, the terminal in RRC connected mode may send a UE information response message ("UEInformationResponse") including the measurement result measured in RRC idle mode to the base station. The time for applying carrier aggregation can be shortened by the above-mentioned measurement in idle mode. The detailed operation is as follows.

[0326] refer to Figure 2F , terminal 2f-01 can establish an RRC connection with base station 2f-02, thereby switching to RRC connection mode (2f-03). If the terminal does not send or receive data for a predetermined reason or a predetermined time, the base station can send an RRC connection release message ("RRCConnnectionRelease"), thereby prompting the terminal to switch to RRC idle mode (2f-05). The RRC connection release message may include a measurement configuration ("measidleConfig") available in RRC idle mode. "measidleConfig" as an information element (hereinafter referred to as "IE") may include at least one of the following parameters.

[0327] - List of carrier frequencies used by the terminal for measurements in RRC idle mode ("measidleCarrierList")

[0328] For example, each carrier frequency used for measurement in RRC idle mode may include at least one of the following: a carrier frequency ("CarrierFreq") including an absolute radio frequency channel number value (hereinafter, referred to as an "ARFCN value"), an indicator indicating a bandwidth available for measurement ("allowedMeasBandwidth"), a cell list ("validityArea") for requesting the terminal to perform idle mode measurement, a cell list ("measCellList") for requesting the terminal to perform idle mode measurement and report measurement results, a threshold value of reference signal received power (hereinafter, referred to as "RSRP"), and an indicator ("reportQuantities") for determining whether the terminal reports a reference signal received quality (hereinafter, referred to as RSRQ) of a cell measured by idle mode measurement, and indicating whether the terminal reports a result value of a cell measured by idle mode measurement using RSRP or RSRQ or using both RSRP and RSRQ.

[0329] • One or more carrier frequency lists may be used for measurements in RRC idle mode. For example, depending on the radio access technology, the carrier frequency lists may be represented as distinguished as "measidleCarrierListEUTRA" and "measidleCarrierListNR".

[0330] - A value indicating the time during which the terminal performs measurements in RRC idle mode ("measidleDuration")

[0331] For example, the value may be the value of timer T311 or the value of a new timer T3xx.

[0332] • The terminal may perform idle mode measurements after receiving an RRC connection release message from the base station before the value expires.

[0333] In the case where the RRC connection release message includes "measidleConfig" in step 2f-05, the terminal 2f-01 can delete "VarMeasidleConfig" and "VarMeasidleReport" as UE variables. In addition, the terminal can store a value indicating the time during which measurements in RRC idle mode are performed in "measidleConfig" (for example, "measidleDuration") and can apply the corresponding value to drive the timer. If the RRC connection release message includes a list of carrier frequencies used by the terminal for measurements in RRC idle mode, the terminal can store the list and can perform idle mode measurements based on the stored list while the timer is operating with a supported carrier (2f-11).

[0334] If the RRC connection release message does not include the carrier frequency list, the terminal may find and camp on a suitable cell through a cell selection procedure and / or a cell reselection procedure, thereby receiving system information from the cell (2f-10).

[0335] If a carrier frequency list ("measidleConfigSIB") for measurements in RRC idle mode is included in the received system information, and if the timer is still operating, the terminal can store the received "measidleConfigSIB" or replace the old list with the "measidleConfigSIB", and can perform idle mode measurements based on the corresponding list when the timer is being driven with a supported carrier (2f-11).

[0336] The idle mode measurement operation can be configured to be performed only on frequencies that meet predetermined conditions. For example, the terminal has a supportable subcarrier spacing (SCS), and there is an SCS that can be supported at a specific frequency. If the SCS supported by the terminal is not supported at a specific frequency, the terminal cannot use the frequency. Therefore, it is not necessary to perform idle mode measurement operations on the frequency.

[0337] According to the disclosure, if a specific frequency does not support the SCS supported by the terminal, the terminal does not perform idle mode measurement operation on the frequency. If "measidleConfigSIB" is not included in the system information broadcast by the target cell, the terminal can stop the idle mode measurement being performed based on the cell reselection process.

[0338] Terminal 2f-01 can trigger random access to establish an RRC connection with base station 2f-02 (2f-13). When random access is triggered, the terminal can select a PRACH timing and can send a random access preamble to the base station (2f-15). Upon receiving the random access preamble, the base station can send a random access response (hereinafter referred to as "RAR") message to the terminal in response thereto (2f-20). Terminal 2f-01 in RRC idle mode can establish reverse link transmission synchronization with base station 2f-02 through steps 2f-15 and 2f-20.

[0339] The terminal 2f-01 in RRC idle mode that has established reverse link transmission synchronization can perform an RRC connection establishment process with the base station 2f-02. First, the terminal can send an RRC connection establishment request message ("RRCConnectionRequest") to the base station (2f-25). The message may include, for example, at least one of information about the identifier of the terminal ("ue-Identity"), information about the reason for establishing the RRC connection ("establishmentCause"), etc.

[0340] If the RRC connection establishment request message is received, the base station may send an RRC connection establishment message ("RRCConnectionSetup") to the terminal (2f-30). The message may include radio resource configuration information ("RadioResourceConfigDedicated", "radioBearerConfig" or "masterCellGroup"). If the RRC connection establishment message is received, the terminal may configure the radio resource configuration information and then may switch to the RRC connection mode (2f-31). The RRC connection establishment may involve signaling a connection of radio bearer 1 (SRB1). Therefore, RRC messages as control messages between the terminal and the base station, RRC messages including NAS messages, or initial NAS messages may be sent and received through SRB1.

[0341] If the system information received in step 2f-10 includes an indicator ("idleModeMeasurements") indicating that the base station is capable of processing idle mode measurements of the terminal, and if "VarMeasidleReport" as a variable of the terminal includes idle mode measurement information by performing idle mode measurements in step 2f-11, the terminal that has switched to RRC connection mode can include an indicator ("idleMeasAvailable") indicating that reporting idle mode measurements is feasible in the RRC connection setup completion message. If a driven timer (e.g., T311 or T3xx) is running, the terminal can stop the timer. In addition, the terminal can send an RRC connection setup completion message ("RRCConnectionSetupComplete") to the base station via SRB1 (2f-35). The message may include a service request message for the terminal to request the AMF or MME for bearer configuration for a predetermined service.

[0342] If the RRC connection establishment process is successfully performed, the base station 2f-02 can perform an RRC connection reconfiguration process with the terminal 2f-01. First, the base station can send an RRC connection reconfiguration message ("RRCConnectionReconfiguration") to the terminal (2f-40). The message may include configuration information about a data radio bearer (DRB) for processing user data, configuration information about SRB1 and / or SRB2 through which control messages can be sent and received, or a measurement configuration ("measConfig"). Upon receiving the RRC connection reconfiguration message, the terminal can apply the above information, and can then send an RRC connection reconfiguration completion message ("RRCCoonectionReconfigurationComplete") to the base station (2f-45).

[0343] If the RRC connection establishment completion message includes an indicator indicating that reporting idle mode measurements is feasible ("idleMeasAvailable") in step 2f-35, the base station 2f-02 can perform the UE information process regarding the terminal 2f-01. In the above steps 2f-40 and 2f-45, the UE information process can be performed directly without performing the RRC connection reconfiguration process. The base station can include an indicator ("idleModeMeasurementReq") requesting the results of measurements in RRC idle mode in the UE information request message ("UEInformationRequest") and can send it to the terminal in RRC connected mode (2f-50). If security is successfully configured, the terminal that has received the UE information request message can perform the following series of processes.

[0344] 1> If the UE information request message includes an indicator for requesting measurement results in RRC idle mode ("idleModeMeasurementReq"), and if the terminal stores "VarMeasidleReport",

[0345] 2> The terminal sets the "measResultListidle" included in the UE information response message ("UEInformationResponse") to the "measReportidle" value (or "idleMeasReport" value) in "VarMeasidleReport".

[0346] 2> If it is identified that the UE information response message is successfully sent from the lower layer, the terminal discards "VarMeasidleReport".

[0347] 1> The terminal submits a UE information request message ("UEInformationResponse") to the lower layer through SRB1. Then, the terminal can send a UE information response message ("UEInformationResponse") including a result list ("measResultListidle") measured in RRC idle mode to the base station (2f-55).

[0348] In the above description, "measResultidle" as IE indicates a list obtained by an operation in which the terminal configures "measResultidle" as IE for each of one or more adjacent inter-frequency carriers in RRC idle mode. The terminal according to the embodiment may apply at least one of the following methods for configuring "measResultidle" for each adjacent inter-frequency carrier when sending a UE information response message.

[0349] Method 1: Each adjacent inter-frequency carrier may optionally include a measurement result of a serving cell ("measResultServingCell") and may optionally include measurement results of one or more neighboring cells ("MeasResultNeighCell") through idle mode measurement.

[0350] The optional inclusion of the measurement result of the serving cell is due to the fact that it may not be necessary to perform repeated reporting for multiple adjacent inter-frequency carriers, because the terminal may only have one serving cell in RRC idle mode. For example, "measResultServingCell" may be configured to have a value of 0 or 1 (or "false" or "true") for each adjacent inter-frequency carrier, and if "measResultServingCell" has a value of 0 (or "false"), the corresponding value may not be included.

[0351] If each neighboring inter-frequency carrier includes the measurement result of the serving cell ("measResultServingCell"), the same measurement result of the serving cell may be included.

[0352] The measurement result of the serving cell ("measResultServingCell") may include at least one of the following result values, or may not include at least one of the following result values ​​at all.

[0353] RSRP result ("rsrpResult")

[0354] RSRQ result ("rsrqResult")

[0355] For each adjacent inter-frequency carrier, the measurement result of the adjacent cell may include at least one of the following parameters.

[0356] >Carrier frequency ("CarrierFreq") containing an absolute radio frequency channel number value (hereinafter, referred to as an "ARFCN value")

[0357] The physical cell identifier ("phyCellId" of each neighboring cell

[0358] RSRP result ("rsrpResult")

[0359] RSRQ result ("rsrqResult")

[0360] If there are no measurement results of neighboring cells for all neighboring inter-frequency carriers, "measResultListidle" may not be included in the UEInformationResponse message.

[0361] Method 2: Each adjacent inter-frequency carrier may include a measurement result of a serving cell ("measResultServingCell") through idle mode measurement, and may optionally include measurement results of one or more neighboring cells ("MeasResultNeighCell").

[0362] Each adjacent inter-frequency carrier includes the measurement result of the serving cell and includes the same measurement result. In addition, if each adjacent inter-frequency carrier does not include the measurement result of the adjacent cell, the corresponding adjacent inter-frequency carrier is not included in "measResultidle". If there is no measurement result of the adjacent cell for all adjacent inter-frequency carriers, "measResultListidle" may not be included in the UE information response message.

[0363] The measurement result of the serving cell ("measResultServingCell") may include at least one of the following result values.

[0364] >RSRP result ("rsrpResult")

[0365] RSRQ result ("rsrqResult")

[0366] The measurement result of the neighboring cell of the corresponding neighboring inter-frequency carrier may include at least one of the following parameters.

[0367] >Carrier frequency ("CarrierFreq") containing an absolute radio frequency channel number value (hereinafter, referred to as an "ARFCN value")

[0368] The physical cell identifier ("phyCellId") of each neighboring cell

[0369] RSRP result ("rsrpResult")

[0370] RSRQ result ("rsrqResult")

[0371] If the UE information response message includes "measResultListidle" in step 2f-55, the base station 2f-02 can perform an RRC connection reconfiguration process with the terminal 2f-01. First, the base station can send an RRC connection reconfiguration message ("RRCConnectionReconfiguration") to the terminal (2f-60). The message may include configuration information about a data radio bearer (DRB) for processing user data, configuration information about SRB1 and / or SRB2 through which control messages can be sent and received, or a measurement configuration ("measConfig"). Upon receiving the RRC connection reconfiguration message, the terminal can apply the above information, and can then send an RRC connection reconfiguration completion message ("RRCCoonectionReconfigurationComplete") to the base station (2f-65).

[0372] The RRC connection reconfiguration message (2f-60) may include common configuration parameters (SCell group configuration) for simultaneously setting configurations for multiple SCells or configuration parameters (SCell configuration) for each SCell. In the case where the RRC connection reconfiguration message includes common configuration parameters for multiple SCells, at least one of the following methods may be applied.

[0373] Method 1: A common parameter for each SCell group may be included (e.g., "SCellGroupToddModList" or "SCellGroupTeleaseList")

[0374] Since there may be multiple SCell groups, an SCell group identifier for identifying the SCell group may be included.

[0375] Common parameters for the corresponding SCell group may be included (e.g., “sCellConfigCommon” or “sCellGroupCommonConfig”).

[0376] · A list ("sCellToAddModList") for adding or modifying one or more cells to each SCell group or in each SCell group may be included. At this time, the initial state of each SCell may be set to an activated state, a dormant state, or a deactivated state.

[0377] • A list ("sCellToReleaseList") for releasing one or more cells from each SCell group may be included.

[0378] Method 2: A common parameter for the corresponding SCell group and a different parameter for the corresponding SCell in each SCell group (eg, "SCellGroupToAddModList" or "SCellGroupToReleaseList") may be included.

[0379] Since there may be multiple SCell groups, an SCell group identifier for identifying the SCell group may be included.

[0380] Common parameters for the corresponding SCell group may be included (e.g., “sCellConfigCommon” or “sCellGroupCommonConfig”).

[0381] · A list ("sCellToAddModList") for adding or modifying one or more cells to each SCell group or in each SCell group may be included. At this time, the initial state of each SCell may be set to an activated state, a dormant state, or a deactivated state.

[0382] An indicator indicating incremental configuration may be included so that different parameters are applied to the corresponding SCell in each SCell group. If a specific SCell includes the indicator, the common parameters of the SCell group to which the specific SCell belongs may be applied. If the specific SCell does not include the indicator, the common parameters of the SCell group and other parameters may be further included, or only the parameters of the corresponding SCell may be included.

[0383] • A list ("sCellToReleaseList") for releasing one or more cells from each SCell group may be included.

[0384] The base station may use a MAC control element (hereinafter referred to as "MAC CE") to indicate the state (activated state, dormant state, or deactivated state) of each SCell configured to the terminal (2f-70), thereby applying carrier aggregation.

[0385] The disclosed idle mode measurement operation can be applied to the deactivated mode in the same manner.

[0386] Figure 2G is a flow chart illustrating the operation of the terminal in the disclosure.

[0387] In step 2g-05, the terminal may receive an idle / deactivated mode measurement configuration from the base station. The measurement configuration may be included in an RRC release message used to switch the terminal from a connected mode to an idle or deactivated mode, or may be provided through system information.

[0388] In step 2g-10, the terminal may perform the configured idle mode measurement operation on the frequency that meets the predetermined condition. For example, the terminal may perform the idle mode measurement operation only on the frequency that supports the SCS supported by the terminal.

[0389] In step 2g-15, the terminal may switch to a connection mode with a single base station.

[0390] In step 2g-20, the terminal may include an indicator indicating that the terminal stores the measurement result collected in the idle or deactivated mode in a predetermined RRC message, and may then send it to the base station.

[0391] In step 2g-25, the terminal receives an RRC message from the base station requesting the terminal to report the stored measurement results.

[0392] In step 2g-30, the terminal may configure the measurement result as a predetermined IE, and may then send it to the base station. The IE "measResultidle" may include a single IE "measResultServingCell" containing the serving cell measurement result and a single IE "measResultperCarrierList" containing the frequency measurement result. The "measResultperCarrierList" may consist of an IE "measResultCarrier" containing frequency-specific measurement results. The IE "measResultCarrier" includes a field indicating carrier frequency information of a frequency, and includes a list of IEs containing PCI information about cells belonging to the corresponding frequency and measurement results corresponding to the corresponding cells.

[0393] In step 2g-35, the terminal may receive SCell adding related configuration information from the base station.

[0394] In step 2g-40, the terminal may apply the configuration information provided from the base station and may perform SCell operations.

[0395] Figure 2H is a flow chart illustrating the operation of a base station in the disclosure.

[0396] In step 2h-05, the base station may provide the idle mode measurement configuration to the terminal using a dedicated RRC message or system information.

[0397] In step 2h-10, the base station switches the terminal to the connection mode through the establishment process with the terminal.

[0398] In step 2h-15, the base station may receive an indicator from the terminal indicating that the measurement results collected in the idle or deactivated mode are stored in the terminal.

[0399] In step 2h-20, the base station sends an RRC message to the terminal to request the terminal to report the stored measurement results.

[0400] In step 2h-25, the base station receives a report of idle mode measurement results from the terminal.

[0401] In step 2h-30, the base station can use the result to determine whether to configure an SCell for the terminal.

[0402] In step 2h-35, the base station provides the terminal with configuration information related to the addition of the SCell.

[0403] The method for operating a terminal proposed in the disclosure may include: receiving an idle mode measurement configuration from a base station; when the terminal enters idle mode, performing idle mode measurement based on the measurement configuration; if the terminal enters connected mode, generating (or obtaining) a measurement result based on the result of performing the measurement; and reporting the measurement result to the base station, wherein the measurement result of a carrier frequency that does not support a subcarrier spacing (SCS) supported by the terminal among the carrier frequencies included in the carrier frequency list included in the measurement configuration may not be reported.

[0404] In addition, the measurement result may include a reference signal received power (RSRP) and a reference signal received quality (RSRQ) of the serving cell, and the measurement result may also include a measurement result of each carrier frequency list.

[0405] In addition, the measurement result of each carrier frequency list may include the carrier frequency and the measurement result of each cell list of the carrier frequency, and the measurement result of each cell list may include a physical cell ID, an RSRP of the cell, and an RSRQ of the cell.

[0406] In addition, the measurement configuration may include a carrier frequency list and timer information indicating a time for performing measurement in an idle mode, and the measurement configuration is received through at least one of a radio resource control (RRC) message and a system information block (SIB).

[0407] In addition, sending the measurement result may include: sending an RRC connection establishment complete message to the base station, the message including an indicator indicating that reporting of idle mode measurements is feasible; receiving a message requesting the measurement result from the base station; and sending the measurement result to the base station.

[0408] Fig.2I is a diagram illustrating a structure of a terminal in the disclosure.

[0409] refer to Fig.2IThe terminal includes a radio frequency (RF) processor 2i-10, a baseband processor 2i-20, a storage unit 2i-30 and a controller 2i-40.

[0410] The RF processor 2i-10 performs functions such as frequency band conversion and signal amplification for sending and receiving signals through a radio channel. That is, the RF processor 2i-10 up-converts the baseband signal provided by the baseband processor 2i-20 into an RF band signal, thereby transmitting the RF band signal through the antenna, and down-converts the RF band signal received through the antenna into a baseband signal. For example, the RF processor 2i-10 may include a transmitting filter, a receiving filter, an amplifier, a mixer, an oscillator, a digital-to-analog converter (DAC), an analog-to-digital converter (ADC), etc. Although in Fig.2I Only one antenna is shown in the figure, but the terminal can have multiple antennas. In addition, the RF processor 2i-10 may include multiple RF chains. In addition, the RF processor 2i-10 can perform beamforming. In order to perform beamforming, the RF processor 2i-10 can adjust the phase and amplitude of the signal sent and received through multiple antennas or antenna elements. In addition, the RF processor can perform MIMO and can receive multiple layers when performing MIMO operation.

[0411] The baseband processor 2i-20 performs the conversion function between the baseband signal and the bit string according to the physical layer specification of the system. For example, when sending data, the baseband processor 2i-20 encodes and modulates the transmission bit string to generate complex symbols. In addition, when receiving data, the baseband processor 2i-20 demodulates and decodes the baseband signal provided by the RF processor 2i-10 to recover the received bit string. For example, in the case of applying the orthogonal frequency division multiplexing (OFDM) scheme, when sending data, the baseband processor 2i-20 generates complex symbols by encoding and modulating the transmission bit string, maps the complex symbols to subcarriers, and then configures OFDM symbols through inverse fast Fourier transform (IFFT) operations and cyclic prefix (CP) insertion. In addition, when receiving data, the baseband processor 2i-20 divides the baseband signal provided by the RF processor 2i-10 into OFDM symbol units, recovers the signal mapped to the subcarrier through a fast Fourier transform (FFT) operation, and then recovers the received bit string through demodulation and decoding.

[0412] The baseband processor 2i-20 and the RF processor 2i-10 send and receive signals as described above. Therefore, the baseband processor 2i-20 and the RF processor 2i-10 can be referred to as a "transmitter", "receiver", "transceiver" or "transceiver". In addition, at least one of the baseband processor 2i-20 and the RF processor 2i-10 may include multiple communication modules to support multiple different radio access technologies. In addition, at least one of the baseband processor 2i-20 and the RF processor 2i-10 may include different communication modules to process signals in different frequency bands. For example, different radio access technologies may include wireless LAN (e.g., IEEE802.11), cellular networks (e.g., LTE), etc. In addition, different frequency bands may include ultra-high frequency (SHF) (e.g., 2.NRHz or NRHz) bands or millimeter wave (e.g., 60GHz) bands.

[0413] The storage unit 2i-30 stores data such as basic programs, applications, and configuration information for the operation of the terminal. Specifically, the storage unit 2i-30 can store information related to a second access node that performs wireless communication using a second radio access technology. In addition, the storage unit 2i-30 provides the stored data in response to a request from the control unit 2i-40.

[0414] The controller 2i-40 controls the overall operation of the terminal. For example, the controller 2i-40 sends and receives signals through the baseband processor 2i-20 and the RF processor 2i-10. In addition, the controller 2i-40 records data in the storage unit 2i-30 and reads data from the storage unit 2i-30. To this end, the controller 2i-40 may include at least one multi-connection processor 2i-42. For example, the controller 2i-40 may include a communication processor (CP) for controlling communication and an application processor (AP) for controlling high layers such as application programs.

[0415] Figure 2J is a block diagram illustrating a configuration of a master base station in a wireless communication system according to an embodiment.

[0416] like Figure 2J As shown, the base station includes an RF processor 2j-10, a baseband processor 2j-20, a backhaul transceiver 2j-30, a storage unit 2j-40 ​​and a controller 2j-50.

[0417] The RF processor 2j-10 performs functions of sending and receiving signals through a radio channel, such as frequency band conversion and signal amplification. That is, the RF processor 2j-10 up-converts the baseband signal provided by the baseband processor 2j-20 into an RF band signal, thereby sending the RF band signal through the antenna, and down-converts the RF band signal received by the antenna into a baseband signal. For example, the RF processor 2j-10 may include a transmit filter, a receive filter, an amplifier, a mixer, an oscillator, a DAC, an ADC, etc. Although only one antenna is shown in the figure, the first access node may have multiple antennas. In addition, the RF processor 2j-10 may include multiple RF chains. In addition, the RF processor 2j-10 may perform beamforming. In order to perform beamforming, the RF processor 2j-10 may adjust the phase and amplitude of the signal sent and received through multiple antennas or antenna elements. The RF processor can perform downlink MIMO operations by sending one or more layers.

[0418] The baseband processor 2j-20 performs a conversion function between a baseband signal and a bit string according to the physical layer specification of the first radio access technology. For example, when sending data, the baseband processor 2j-20 encodes and modulates the transmitted bit string to generate a complex symbol. In addition, when receiving data, the baseband processor 2j-20 demodulates and decodes the baseband signal provided from the RF processor 2j-10 to recover the received bit string. For example, in the case of applying the OFDM scheme, when sending data, the baseband processor 2j-20 generates a complex symbol by encoding and modulating the transmitted bit string, maps the complex symbol to a subcarrier, and then configures the OFDM symbol through an IFFT operation and CP insertion. In addition, when receiving data, the baseband processor 2j-20 divides the baseband signal provided from the RF processor 2j-10 into OFDM symbol units, recovers the signal mapped to the subcarrier through an FFT operation, and then recovers the received bit string through demodulation and decoding. The baseband processor 2j-20 and the RF processor 2j-10 send and receive signals as described above. Therefore, the baseband processor 2j-20 and the RF processor 2j-10 can be referred to as a "transmitter", "receiver", "transceiver", "transceiver" or "wireless transceiver".

[0419] The backhaul transceiver 2j-30 provides an interface for performing communication with other nodes in the network. That is, the backhaul transceiver 2j-30 converts a bit string sent from the main base station to another node such as a secondary base station, a core network, etc. into a physical signal, and converts a physical signal received from other nodes into a bit string.

[0420] The storage unit 2j-40 ​​stores data such as basic programs, applications, and configuration information for the operation of the main base station. Specifically, the storage unit 2j-40 ​​can store information about the bearer assigned to the connected terminal, measurement results reported from the connected terminal, etc. In addition, the storage unit 2j-40 ​​can store information as a criterion for determining whether to provide multiple connections to the terminal or release multiple connections. In addition, the storage unit 2j-40 ​​provides the stored data in response to a request from the controller 2j-50.

[0421] The controller 2j-50 controls the overall operation of the main base station. For example, the controller 2j-50 sends and receives signals through the baseband processor 2j-20 and the RF processor 2j-10 or the backhaul transceiver 2j-30. In addition, the controller 2j-50 records data in the storage unit 2j-40 ​​and reads data from the storage unit 2j-40. To this end, the controller 2j-50 may include at least one multi-connection processor 2j-52.

[0422] Meanwhile, in the drawings illustrating the disclosed methods, the order of description does not necessarily correspond to the order of execution, and the order may be changed or the implementations may be performed in parallel.

[0423] Alternatively, the drawings illustrating the disclosed methods may include only some components, excluding other components, without departing from the scope of the disclosure.

[0424] In addition, the disclosure may be performed by a combination of all or some of the contents included in the various embodiments without departing from the scope of the disclosure.

[0425] Although the disclosure has been described with various embodiments, various changes and modifications may be suggested to one skilled in the art. The disclosure is intended to encompass such changes and modifications as fall within the scope of the appended claims.

Claims

1. A method performed by a terminal in a communication system, the method include: receiving a radio resource control RRC release message from a base station, the message including duration information and valid area information for measurement in an RRC idle state, wherein the valid area information indicates a frequency list and a cell list; In response to receiving the RRC release message, entering an RRC idle state and starting a timer having a value set to the duration information; When the timer runs, performing measurement in an RRC idle state based on the first carrier list information, wherein the first carrier list information is stored in the terminal based on the RRC release message; and In a case where cell reselection is performed while the timer is running, identifying whether the reselected cell requires measurement in the RRC idle state based on the frequency and physical cell identity of the serving cell and the frequency list and cell list indicated by the valid area information; and In case the measurement in the RRC idle state is not required by the reselected cell, the timer is stopped.

2. The method according to claim 1, in, A cell list is indicated for each of the frequency lists.

3. The method according to claim 1, further comprising: include: identifying system information associated with measurement performed in an RRC idle state in a case where cell reselection is performed while the timer is running and the RRC release message does not include the first carrier list information; and In a case where the system information includes second carrier list information for measurement performed in the RRC idle state, replacing the first carrier list information with the second carrier list information, The second carrier list information includes at least one of information about one or more Evolved Universal Terrestrial Radio Access (E-UTRA) carrier lists to be measured in the RRC idle state and information about one or more New Radio Access (NR) carrier lists to be measured in the RRC idle state.

4. The method according to claim 1, in, The first carrier list information of the system information includes information about one or more Evolved Universal Terrestrial Radio Access E-UTRA carrier lists to be measured in the RRC idle state, and at least one of one or more New Radio Access NR carrier lists to be measured in the RRC idle state.

5. A method performed by a base station in a communication system, the method include: identifying a radio resource control RRC release message, the message including duration information and valid area information for measurement in an RRC idle state, wherein the valid area information indicates a frequency list and a cell list; and Sending an RRC release message to the terminal; The RRC release message instructs the terminal to enter the RRC idle state and start a timer having a value set to the duration information, Wherein, when the timer is running, the first carrier list information identified based on the RRC release message is used to perform measurement in the RRC idle state, Wherein, in the case where cell reselection is performed when the timer is running, whether the reselected cell requires measurement in the RRC idle state is identified based on the frequency and physical cell identity of the serving cell and the frequency list and cell list indicated by the valid area information, and Wherein, when the measurement in the RRC idle state is not required by the reselected cell, the timer is stopped.

6. The method according to claim 5, in, A cell list is indicated for each of the frequency lists.

7. The method according to claim 5, in, Based on identification that cell reselection is performed while the timer is running and the RRC release message does not include the first carrier list information, the first carrier list system information is replaced with the second carrier list information of the system information, and The second carrier list information includes at least one of information about one or more Evolved Universal Terrestrial Radio Access (E-UTRA) carrier lists to be measured in the RRC idle state and information about one or more New Radio Access (NR) carrier lists to be measured in the RRC idle state.

8. The method according to claim 5, in, The first carrier list information of the system information includes information about one or more Evolved Universal Terrestrial Radio Access E-UTRA carrier lists to be measured in the RRC idle state, and at least one of one or more New Radio Access NR carrier lists to be measured in the RRC idle state.

9. A terminal in a communication system, include: Transceiver; as well as A controller is coupled to the transceiver and is configured to: receiving a radio resource control RRC release message from a base station, the message including duration information and valid area information for measurement in an RRC idle state, wherein the valid area information indicates a frequency list and a cell list, In response to receiving the RRC release message, entering an RRC idle state and starting a timer having a value set to the duration information; When the timer is running, performing measurement in an RRC idle state based on the first carrier list information, wherein the first carrier list information is stored in the terminal based on the RRC release message, and In the case where cell reselection is performed while the timer is running, identifying whether the reselected cell requires measurement in the RRC idle state based on the frequency and physical cell identity of the serving cell and the frequency list and cell list indicated by the valid area information, and In case the measurement in the RRC idle state is not required by the reselected cell, the timer is stopped.

10. The terminal according to claim 9, in, A cell list is indicated for each of the frequency lists.

11. The terminal according to claim 9, in, The controller is also controlled to: identifying system information associated with measurements performed in an RRC idle state in a case where cell reselection is performed while the timer is running and the RRC release message does not include the first carrier list information, and In a case where the system information includes second carrier list information for measurement performed in the RRC idle state, replacing the first carrier list information with the second carrier list information, The second carrier list information includes at least one of information about one or more Evolved Universal Terrestrial Radio Access (E-UTRA) carrier lists to be measured in the RRC idle state and information about one or more New Radio Access (NR) carrier lists to be measured in the RRC idle state.

12. The terminal according to claim 9, in, The first carrier list information of the system information includes information about one or more Evolved Universal Terrestrial Radio Access E-UTRA carrier lists to be measured in the RRC idle state, and at least one of one or more New Radio Access NR carrier lists to be measured in the RRC idle state.

13. A base station in a communication system, include: Transceiver; as well as A controller is coupled to the transceiver and is configured to: identifying a radio resource control RRC release message, the message including duration information and valid area information for measurement in an RRC idle state, wherein the valid area information indicates a frequency list and a cell list, and Send an RRC release message to the terminal, The RRC release message instructs the terminal to enter the RRC idle state and start a timer having a value set to the duration information, Wherein, when the timer is running, the first carrier list information identified based on the RRC release message is used to perform measurements in the RRC idle state, wherein, in the case where cell reselection is performed when the timer is running, whether the reselected cell requires measurement in the RRC idle state is identified based on the frequency and physical cell identifier of the serving cell and the frequency list and cell list indicated by the valid area information, and wherein, in the case where measurement in the RRC idle state is not required by the reselected cell, the timer is stopped.

14. The base station according to claim 13, in, A cell list is indicated for each of the frequency lists.

15. The base station according to claim 13, in, Based on identification that cell reselection is performed while the timer is running and the RRC release message does not include the first carrier list information, the first carrier list system information is replaced with the second carrier list information of the system information, and The second carrier list information includes at least one of information about one or more Evolved Universal Terrestrial Radio Access (E-UTRA) carrier lists to be measured in the RRC idle state and information about one or more New Radio Access (NR) carrier lists to be measured in the RRC idle state, and The first carrier list information of the system information includes information about one or more Evolved Universal Terrestrial Radio Access E-UTRA carrier lists to be measured in the RRC idle state, and at least one of the one or more New Radio Access NR carrier lists to be measured in the RRC idle state.

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