Method and apparatus for handover between cells of user terminal

Abstract

A user terminal comprises a communication circuit connected to a network via a first cell, which is a serving cell of the user terminal, among a plurality of cells provided in the network, at least one processor including processing circuitry, and a memory including one or more storage media storing instructions, wherein the instructions, when executed by the at least one processor, may cause the user terminal to: receive a measurement configuration from a first base station providing the first cell; when an event corresponding to a measurement report occurs, generate a measurement report for a cell provided by a base station in the vicinity of the user terminal; transmit the generated measurement report to the first base station; receive, from the first base station, a cell global identity (CGI) configuration for a second cell; when CGI measurement through discontinuous reception (DRX) is configured in the received CGI configuration for the second cell, identify whether a condition regarding prioritizing the CGI measurement is satisfied; on the basis of the condition being satisfied, suspend data transmission and reception with the first base station in at least one of DRX cycles that are periodically repeated according to the DRX; during the suspension of data transmission and reception with the first base station, generate a CGI report for the second cell on the basis of information received from a second base station providing the second cell; and transmit the generated CGI report to the first base station.

Description

Method and device for handover between cells of user terminals

[0001] Hereinafter, a technology for handover between cells of a user terminal is disclosed.

[0002] The self-configuration field is a function that automatically collects and analyzes parameters required for the initial operation of a base station when installing a new or additional base station, and automates procedures such as identifying neighboring base stations, registering relationship settings, and establishing connections with the core network during the initial boot-up process and pre-operation stages of the base station.

[0003] The above self-configuration operation process starts when the base station is powered on and connected to the transmission link, and then performs self-detection functions after basic hardware self-verification. The self-detection functions include detecting the transport type and the length of the antenna cable, and automatically adjusting the receiver path. After performing the self-detection function, the base station sets up the physical transmission link and obtains information about the IP address to be used and the IP addresses of related equipment or services such as the serving gateway, MME (Mobile Mobility Entity), and Configuration server through a connection to a DHCP (Dynamic Host Configuration Protocol) / DNS (Domain Name System) server. After completing this process, the base station can create a secure tunnel to be used for the S1 and X2 links and is ready to communicate with a storage server to obtain new configuration parameters. Neighborhood relationship configuration can also be optionally performed through automated functions.

[0004] The above information may be provided as background information to aid in understanding this document. None of the above is claimed to be prior art related to this document or can be used to determine prior art.

[0005] A user terminal comprises: a communication circuit connected to the network through a first cell, which is a serving cell of the user terminal, among a plurality of cells provided by the network; at least one processor including a processing circuit; And a memory including one or more storage media storing instructions, wherein when the instructions are executed by the at least one processor, the user terminal receives a measurement configuration from a first base station providing the first cell, and when an event corresponding to the measurement report occurs, generates a measurement report for a cell provided by a base station around the user terminal, and transmits the generated measurement report to the first base station, receives a cell global identity configuration (CGI) for a second cell from the first base station, and when the CGI measurement through discontinuous reception (DRX) is configured in the received CGI configuration for the second cell, determines whether a condition for prioritizing the CGI measurement is satisfied, and based on the condition being satisfied, stops transmitting and receiving data with the first base station in at least one of DRX cycles that are periodically repeated according to the DRX, and while the data transmission and reception with the first base station is stopped, the second base station providing the second cell A CGI report for the second cell can be generated based on information received from the base station, and the generated CGI report can be transmitted to the first base station.

[0006] A method performed by a user terminal comprises: receiving a measurement configuration from a first base station providing a first cell, which is a serving cell of the user terminal, among a plurality of cells provided by a network; generating a measurement report for a cell provided by a base station around the user terminal when an event corresponding to the measurement report occurs; transmitting the generated measurement report to the first base station; receiving a cell global identity configuration (CGI) for a second cell from the first base station; confirming whether a condition for prioritizing CGI measurement through discontinuous reception (DRX) is satisfied when the received CGI configuration for the second cell configures CGI measurement; and stopping data transmission and reception with the first base station in at least one of DRX cycles that are periodically repeated according to the DRX based on whether the condition is satisfied. The method may include: generating a CGI report for the second cell based on information received from a second base station providing the second cell while data transmission and reception with the first base station is suspended; and transmitting the generated CGI report to the first base station.

[0007] FIG. 1 is a block diagram illustrating an exemplary configuration of an electronic device according to various embodiments.

[0008] FIG. 2 illustrates an example of a wireless communication environment according to various embodiments.

[0009] FIG. 3 is a block diagram illustrating an example of a functional configuration of a base station according to various embodiments.

[0010] FIG. 4 is a flowchart illustrating an example of a functional configuration of a radio access network (RAN) controller according to various embodiments.

[0011] FIG. 5 is a system diagram showing examples of measurement reports and CGI reports in a wireless communication system according to various embodiments.

[0012] FIG. 6 is a diagram illustrating an example of a case in which a handover fails in a wireless communication system according to various embodiments.

[0013] FIG. 7 is a flowchart illustrating an example of a method for preferentially processing CGI measurements in a wireless communication system according to various embodiments.

[0014] FIG. 8 is a diagram illustrating an example of an operation for determining whether a condition for a user terminal to give priority to CGI measurement is satisfied in a wireless communication system according to various embodiments.

[0015] FIG. 9 is a diagram illustrating an example of an operation of a user terminal switching between activating and deactivating communication with a first base station according to a DRX cycle according to various embodiments.

[0016] FIG. 10 is a diagram illustrating an example of an operation forcing a user terminal to stop transmitting and receiving data with a first base station based on a type of DRX cycle according to various embodiments.

[0017] FIG. 11 is a diagram illustrating an example of an operation forcing a user terminal to stop transmitting and receiving data with a first base station based on omitting to enter a DRX sleep mode in a DRX cycle according to various embodiments.

[0018] FIG. 12 is a diagram illustrating an example of an operation forcing a user terminal to stop transmitting and receiving data with a first base station based on a timer for CGI measurement according to various embodiments.

[0019] Hereinafter, embodiments will be described in detail with reference to the attached drawings. In the description with reference to the attached drawings, identical components are assigned the same reference numerals regardless of the drawing numbers, and redundant descriptions thereof will be omitted.

[0020] In the following description, terms referring to signals (e.g., signal, information, message, signaling), terms referring to resources (e.g., symbol, slot, subframe, radio frame, subcarrier, resource element (RE), resource block (RB), bandwidth part (BWP), occasion), terms for operational states (e.g., step, operation, procedure), terms referring to data (e.g., packet, user stream, information, bit, symbol, codeword), terms referring to channels, terms referring to network entities, terms referring to components of devices, etc. are examples for convenience of description. Therefore, the present disclosure is not limited to the terms described below, and other terms having equivalent technical meanings may be used.

[0021] Additionally, in the present disclosure, expressions such as "more than" or "less than" may be used to determine whether a specific condition is satisfied or fulfilled. However, this is merely a description for expressing an example and does not exclude descriptions of "more than" or "less than." Conditions described as "more than" may be replaced with "more than," conditions described as "less than" may be replaced with "less than," and conditions described as "more than and less than" may be replaced with "more than and less than."

[0022] Additionally, although the present disclosure describes various embodiments using terms used in some communication standards (e.g., 3rd Generation Partnership Project (3GPP), extensible radio access network (xRAN), open-radio access network (O-RAN), etc.), these are merely examples for explanation. The various embodiments of the present disclosure can be easily modified and applied to other communication systems.

[0023] In the present disclosure, a measurement signal may refer to a signal measured by a terminal to obtain signal quality to be used for mobility, admission control, or radio resource management (RRM). For example, the measurement signal may be at least one of a synchronization signal (SS) (e.g., an SS block), a beam reference signal (BRS), a beam refinement reference signal (BRRS), a cell-specific reference signal (CRS), a channel state information-reference signal (CSI-RS), and a demodulation-reference signal (DM-RS). According to embodiments, a base station may transmit not only one type of measurement signal, but also two or more types of measurement signals.

[0024] In the present disclosure, the signal quality may be, for example, at least one of RSRP (reference signal received power), BRSRP (beam reference signal received power), RSRQ (reference signal received quality), RSSI (received signal strength indicator), SINR (signal to interference and noise ratio), CINR (carrier to interference and noise ratio), SNR (signal to noise ratio), EVM (error vector magnitude), BER (bit error rate), or BLER (block error rate). In addition to the examples described above, other terms having equivalent technical meanings or other metrics indicating channel quality may be used. Hereinafter, in the present disclosure, high signal quality means a case where a signal quality value related to a signal size is large or a signal quality value related to an error rate is small. A higher signal quality may mean that a smooth wireless communication environment is guaranteed. In addition, an optimal beam may mean a beam having the highest signal quality among beams.

[0025] FIG. 1 is a block diagram illustrating an exemplary configuration of an electronic device according to various embodiments.

[0026] FIG. 1 is a block diagram of an electronic device (101) within a network environment (100) according to various embodiments. Referring to FIG. 1, in the network environment (100), the electronic device (101) may communicate with an electronic device (102) via a first network (198) (e.g., a short-range wireless communication network), or may communicate with at least one of an electronic device (104) or a server (108) via a second network (199) (e.g., a long-range wireless communication network). According to one embodiment, the electronic device (101) may communicate with the electronic device (104) via the server (108).

[0027] According to one embodiment, the electronic device (101) may include a processor (120), a memory (130), an input module (150), an audio output module (155), a display (160), an audio module (170), a sensor (176), an interface (177), a connection terminal (178), a haptic module (179), a camera (180), a power management module (188), a battery (189), a communication module (190), a subscriber identification module (196), or an antenna module (197). In some embodiments, the electronic device (101) may omit at least one of these components (e.g., the connection terminal (178)), or may have one or more other components added. In some embodiments, some of these components (e.g., the sensor (176), the camera (180), or the antenna module (197)) may be integrated into one component (e.g., the display (160)).

[0028] The processor (120) may be implemented as one or more IC (integrated circuit (or circuitry)) chips and may perform various data processing. The processor (120) may include at least one electrical circuit and may individually or collectively perform distributed processing of instructions (or programs (140), data, etc.) stored in the memory (130). The processor (120) may include a processor assembly including one or more processing circuits. The processor (120) may include any processing circuit that is operative to control the performance and operations of one or more components of the electronic device (101) (e.g., the memory (130), the display (160), the camera (180), the communication circuit, and / or the sensor (176)).

[0029] The processor (120) may, for example, execute software (e.g., a program (140)) to control at least one other component (e.g., a hardware or software component) of the electronic device (101) connected to the processor (120) and perform various data processing or calculations. According to one embodiment, as at least a part of the data processing or calculations, the processor (120) may store commands or data received from other components (e.g., a sensor (176) or a communication module (190)) in a volatile memory (132), process the commands or data stored in the volatile memory (132), and store result data in a non-volatile memory (134). According to one embodiment, the processor (120) may include a main processor (121) (e.g., a central processing unit or an application processor) or a secondary processor (123) (e.g., a graphics processing unit, a neural processing unit (NPU), an image signal processor, a sensor hub processor, or a communication processor)) that can operate independently or together therewith. For example, if the electronic device (101) includes a main processor (121) and a secondary processor (123), the secondary processor (123) may be configured to use less power than the main processor (121) or to be specialized for a specified function. The secondary processor (123) may be implemented separately from the main processor (121) or as a part thereof.

[0030] The auxiliary processor (123) may control at least a portion of functions or states associated with at least one component (e.g., a display (160), a sensor (176), or a communication module (190)) of the electronic device (101), for example, on behalf of the main processor (121) while the main processor (121) is in an inactive (e.g., sleep) state, or together with the main processor (121) while the main processor (121) is in an active (e.g., application execution) state. In one embodiment, the auxiliary processor (123) (e.g., an image signal processor or a communication processor) may be implemented as a part of another functionally related component (e.g., a camera (180) or a communication module (190)). In one embodiment, the auxiliary processor (123) (e.g., a neural network processing unit) may include a hardware structure specialized for processing artificial intelligence models. The artificial intelligence models may be generated through machine learning. This learning can be performed, for example, on the electronic device (101) itself where the artificial intelligence model is executed, or can be performed through a separate server (e.g., server (108)). The learning algorithm can include, for example, supervised learning, unsupervised learning, semi-supervised learning, or reinforcement learning, but is not limited to the examples described above. The artificial intelligence model can include multiple artificial neural network layers.The artificial neural network may be one of a deep neural network (DNN), a convolutional neural network (CNN), a recurrent neural network (RNN), a restricted Boltzmann machine (RBM), a deep belief network (DBN), a bidirectional recurrent deep neural network (BRDNN), a deep Q-network, or a combination of two or more of the above, but is not limited to the examples described above. In addition to, or alternatively to, a hardware structure, an artificial intelligence model may include a software structure.

[0031] The memory (130) can store various data used by at least one component (e.g., processor (120) or sensor (176)) of the electronic device (101). The data can include, for example, software (e.g., program (140)) and input data or output data for commands related thereto. The memory (130) can include volatile memory (132) or non-volatile memory (134).

[0032] The program (140) may be stored as software in the memory (130) and may include, for example, an operating system (142), middleware (144), or an application (146).

[0033] The input module (150) can receive commands or data to be used in a component of the electronic device (101) (e.g., a processor (120)) from an external source (e.g., a user) of the electronic device (101). The input module (150) can include, for example, a microphone, a mouse, a keyboard, a key (e.g., a button), or a digital pen (e.g., a stylus pen).

[0034] The audio output module (155) can output audio signals to the outside of the electronic device (101). The audio output module (155) can include, for example, a speaker or a receiver. The speaker can be used for general purposes, such as multimedia playback or recording playback. The receiver can be used to receive incoming calls. In one embodiment, the receiver can be implemented separately from the speaker or as part of the speaker.

[0035] A display (160) (e.g., a display) can visually provide information to an external device (e.g., a user) of the electronic device (101). The display (160) may include, for example, a display, a holographic device, or a projector and a control circuit for controlling the device. In one embodiment, the display (160) may include a touch sensor configured to detect a touch, or a pressure sensor configured to measure the intensity of a force generated by the touch.

[0036] The audio module (170) can convert sound into an electrical signal, or vice versa, convert an electrical signal into sound. According to one embodiment, the audio module (170) can acquire sound through the input module (150), output sound through the sound output module (155), or an external electronic device (e.g., electronic device (102)) (e.g., speaker or headphone) directly or wirelessly connected to the electronic device (101).

[0037] The sensor (176) can detect the operating status (e.g., power or temperature) of the electronic device (101) or the external environmental status (e.g., user status) and generate an electrical signal or data value corresponding to the detected status. According to one embodiment, the sensor (176) may include, for example, a gesture sensor, a gyro sensor, a barometric pressure sensor, a magnetic sensor, an acceleration sensor, a grip sensor, a proximity sensor, a color sensor, an infrared (IR) sensor, a biometric sensor, a temperature sensor, a humidity sensor, or an illuminance sensor. For example, the sensor (176) may include an inertial measurement unit (IMU).

[0038] The interface (177) may support one or more designated protocols that may be used to directly or wirelessly connect the electronic device (101) with an external electronic device (e.g., the electronic device (102)). In one embodiment, the interface (177) may include, for example, a high definition multimedia interface (HDMI), a universal serial bus (USB) interface, an SD card interface, or an audio interface.

[0039] The connection terminal (178) may include a connector through which the electronic device (101) may be physically connected to an external electronic device (e.g., electronic device (102)). According to one embodiment, the connection terminal (178) may include, for example, an HDMI connector, a USB connector, an SD card connector, or an audio connector (e.g., a headphone connector).

[0040] A haptic module (179) can convert electrical signals into mechanical stimuli (e.g., vibration or movement) or electrical stimuli that a user can perceive through tactile or kinesthetic sensations. In one embodiment, the haptic module (179) can include, for example, a motor, a piezoelectric element, or an electrical stimulation device.

[0041] The camera (180) can capture still images and moving images. In one embodiment, the camera (180) may include one or more lenses, one or more image sensors, one or more image signal processors, or one or more flashes.

[0042] The power management module (188) can manage power supplied to the electronic device (101). According to one embodiment, the power management module (188) can be implemented, for example, as at least a part of a power management integrated circuit (PMIC).

[0043] A battery (189) may power at least one component of the electronic device (101). In one embodiment, the battery (189) may include, for example, a non-rechargeable primary battery, a rechargeable secondary battery, or a fuel cell.

[0044] The communication module (190) may support the establishment of a direct (e.g., wired) communication channel or a wireless communication channel between the electronic device (101) and an external electronic device (e.g., electronic device (102), electronic device (104), or server (108)), and the performance of communication through the established communication channel. The communication module (190) may include one or more communication circuits. The communication module (190) may include one or more communication processors (CPs) that operate independently from the processor (120) (e.g., application processor) and support direct (e.g., wired) communication or wireless communication. According to one embodiment, the communication module (190) may include a wireless communication module (192) (e.g., a cellular communication module, a short-range wireless communication module, or a global navigation satellite system (GNSS) communication module) or a wired communication module (194) (e.g., a local area network (LAN) communication module, or a power line communication module). Among these communication modules, a corresponding communication module may communicate with an external electronic device (104) via a first network (198) (e.g., a short-range communication network such as Bluetooth, WiFi (wireless fidelity) direct, or IrDA (infrared data relation)) or a second network (199) (e.g., a long-range communication network such as a legacy cellular network, a 5G network, a next-generation communication network, the Internet, or a computer network (e.g., a LAN or WAN)). These various types of communication modules may be integrated into a single component (e.g., a single chip) or implemented as a plurality of separate components (e.g., multiple chips).The wireless communication module (192) can verify or authenticate an electronic device (101) within a communication network, such as a first network (198) or a second network (199), using subscriber information (e.g., international mobile subscriber identity (IMSI)) stored in the subscriber identification module (196).

[0045] The wireless communication module (192) can support 5G networks and next-generation communication technologies following the 4G network, such as NR access technology (new radio access technology). The NR access technology can support high-speed transmission of high-capacity data (eMBB (enhanced mobile broadband)), minimization of terminal power and connection of multiple terminals (mMTC (massive machine type communications)), or high reliability and low latency (URLLC (ultra-reliable and low-latency communications)). The wireless communication module (192) can support, for example, a high-frequency band (e.g., mmWave band) to achieve a high data transmission rate. The wireless communication module (192) can support various technologies for securing performance in a high-frequency band, such as beamforming, massive multiple-input and multiple-output (MIMO), full dimensional MIMO (FD-MIMO), array antenna, analog beam-forming, or large scale antenna. The wireless communication module (192) can support various requirements specified in the electronic device (101), an external electronic device (e.g., the electronic device (104)), or a network system (e.g., the second network (199)). According to one embodiment, the wireless communication module (192) can support a peak data rate (e.g., 20 Gbps or more) for eMBB realization, a loss coverage (e.g., 164 dB or less) for mMTC realization, or a U-plane latency (e.g., 0.5 ms or less for downlink (DL) and uplink (UL), or 1 ms or less for round trip) for URLLC realization.

[0046] The antenna module (197) can transmit or receive signals or power to or from an external device (e.g., an external electronic device). In one embodiment, the antenna module (197) may include an antenna including a radiator formed of a conductor or a conductive pattern formed on a substrate (e.g., a PCB). In one embodiment, the antenna module (197) may include a plurality of antennas (e.g., an array antenna). In this case, at least one antenna suitable for a communication method used in a communication network, such as the first network (198) or the second network (199), may be selected from the plurality of antennas by, for example, the communication module (190). A signal or power may be transmitted or received between the communication module (190) and an external electronic device through the selected at least one antenna. In some embodiments, in addition to the radiator, another component (e.g., a radio frequency integrated circuit (RFIC)) may be additionally formed as a part of the antenna module (197).

[0047] According to various embodiments, the antenna module (197) may form a mmWave antenna module. According to one embodiment, the mmWave antenna module may include a printed circuit board, an RFIC disposed on or adjacent a first side (e.g., a bottom side) of the printed circuit board and capable of supporting a designated high-frequency band (e.g., a mmWave band), and a plurality of antennas (e.g., an array antenna) disposed on or adjacent a second side (e.g., a top side or a side side) of the printed circuit board and capable of transmitting or receiving signals in the designated high-frequency band.

[0048] At least some of the above components can be interconnected and exchange signals (e.g., commands or data) with each other via a communication method between peripheral devices (e.g., a bus, GPIO (general purpose input and output), SPI (serial peripheral interface), or MIPI (mobile industry processor interface)).

[0049] According to one embodiment, commands or data may be transmitted or received between an electronic device (101) and an external electronic device (104) via a server (108) connected to a second network (199).

[0050] Each of the external electronic devices (102, 104) and the server (108) may be the same type of device as or different from the electronic device (101). According to one embodiment, all or part of the operations executed by the electronic device (101) may be executed by one or more of the external electronic devices (102, 104) or the server (108). For example, when the electronic device (101) is to perform a certain function or service automatically or in response to a request from a user or another device, the electronic device (101) may, instead of executing the function or service itself or in addition, request one or more external electronic devices to execute at least a part of the function or service. The one or more external electronic devices that receive the request may execute at least a part of the requested function or service, or an additional function or service related to the request, and transmit the result of the execution to the electronic device (101). The electronic device (101) may process the result as is or additionally and provide it as at least a part of a response to the request.

[0051] FIG. 2 illustrates an example of a wireless communication environment according to various embodiments.

[0052] In Fig. 2, a user terminal and a base station are exemplified as some of the nodes that use a wireless channel in a wireless communication system.

[0053] Referring to FIG. 2, the wireless communication environment may include a user terminal (210) (e.g., electronic device (101) of FIG. 1), a first base station (220), a second base station (221), a third base station (222), a fourth base station (223), a fifth base station (224), a sixth base station (225), and a seventh base station (226).

[0054] A user terminal (210) is a device used by a user and can communicate with a base station (e.g., a first base station (220), a second base station (221), a third base station (222), a fourth base station (223), a fifth base station (224), a sixth base station (225), a seventh base station (226)) through a wireless channel. For example, when accessing a wireless network provided by a specific base station, the user terminal (210) can communicate with a specific base station.

[0055] According to one embodiment, the user terminal (210) can be operated without the involvement of a user. The user terminal (210) is a device that performs machine type communication (MTC) and may not be carried by a user. The user terminal (210) may be referred to as a user terminal, as well as a 'user equipment (UE),' a 'mobile station,' a 'subscriber station,' a customer-premises equipment (CPE), a 'remote terminal,' a 'wireless terminal,' a 'user device,' an electronic device,' or other terms having equivalent technical meanings.

[0056] The first base station (220), the second base station (221), the third base station (222), the fourth base station (223), the fifth base station (224), the sixth base station (225), and the seventh base station (226) are network infrastructures that provide wireless access. Each base station has coverage defined as a certain geographical area based on the distance at which a signal can be transmitted. In addition to the base station, the base station may be referred to as an 'access point (AP)', 'eNodeB (eNB)', '5th generation node', 'next generation nodeB (gNB)', 'wireless point', 'transmission / reception point (TRP)', or other terms having equivalent technical meanings.

[0057] The RAN controller (250) may be a device for controlling RAN elements and resources through data collection and operations. According to one embodiment, the RAN controller (250) may function as a Near-RT RIC of the O-RAN standard. According to another embodiment, the RAN controller (250) may function as a Non-RT RIC of the O-RAN standard. According to yet another embodiment, the RAN controller (250) may be a separate device for functioning as both a Non-RT RIC and a Near-RT RIC of the O-RAN standard. According to yet another embodiment, the RAN controller may be a device for receiving a report message defined separately from the O-RAN standard from each base station and transmitting a control message to each base station.

[0058] The RAN controller (250) can be connected to the first base station (220), the second base station (221), the third base station (222), the fourth base station (223), the fifth base station (224), the sixth base station (225), and the seventh base station (226). Hereinafter, the operation of the base station is described based on the first base station (220), but the description of the first base station (220) can be applied in the same or similar manner to other base stations (e.g., the second base station (221), the third base station (222), the fourth base station (223), the fifth base station (224), the sixth base station (225), and the seventh base station (226)).

[0059] The RAN controller (250) may receive network information of the first base station (220) from the first base station (220). The network information may refer to information related to a radio access network (RAN) provided by the first base station (220). According to one embodiment, the network information of the first base station (220) may include information on one or more cells provided by the first base station (220). Furthermore, according to one embodiment, the network information of the first base station (220) may include information on one or more user terminals served by the first base station (220). Furthermore, according to one embodiment, the network information of the first base station (220) may include a measurement report for each of the one or more user terminals served by the first base station (220). The first base station (220) may collect the measurement reports received from each user terminal. Additionally, according to one embodiment, the network information of the first base station (220) may include a measurement configuration of each cell provided by the first base station (220). The measurement configuration may include at least one parameter related to an event for triggering a measurement report. Additionally, according to one embodiment, the network information of the first base station (220) may include channel information of a user terminal serviced by the first base station (220). Additionally, according to one embodiment, the network information of the first base station (220) may include resource usage information allocated by the first base station (220).

[0060] A cell can refer to an area covered by a single base station. A single base station may cover one cell or multiple cells. Here, multiple cells may be distinguished by the frequency they support and / or the sectors they cover. In the following description, "base station" may be used as a term encompassing a cell, or "cell" may be used as a term referring to a base station.

[0061] A serving cell is a cell that provides user equipment (UE) and upper layer signaling (e.g., radio resource control (RRC) signaling), and may refer to one cell or multiple cells. If the user equipment is not configured to support carrier aggregation (CA) and dual connectivity (DC), the serving cell may be one cell including a primary cell. If the user equipment is configured to support CA or user equipment, the serving cell may be a set of one or more cells including both a primary cell and at least one secondary cell.

[0062] FIG. 3 is a block diagram illustrating an example of a functional configuration of a base station according to various embodiments.

[0063] The base station (300) illustrated in FIG. 3 can be understood as a configuration of each base station (e.g., the first base station (210) of FIG. 2) illustrated in FIG. 2. Terms such as "... unit" and "... unit" used hereinafter mean a unit that processes at least one function or operation, which can be implemented by hardware, software, or a combination of hardware and software.

[0064] Referring to FIG. 3, the base station (300) may include a processor (301), a memory (303), and a transceiver (305).

[0065] The processor (301) controls the overall operations of the base station (300). For example, the processor (310) writes and reads data to and from the memory (303). For example, the processor (310) transmits and receives signals via the transceiver (305). Although FIG. 3 illustrates one processor, the embodiments of the present disclosure are not limited thereto. The base station (300) may include at least one processor to perform the embodiments of the present disclosure. The processor (301) may be referred to as a control unit or a control means. According to various embodiments, the processor (301) may control the device to perform the operations of the base station (300) according to the embodiments of the present disclosure.

[0066] The memory (303) can store data such as basic programs, application programs, and configuration information for the operation of the base station (300). The memory (303) can be composed of volatile memory, non-volatile memory, or a combination of volatile memory and non-volatile memory. In addition, the memory (303) provides stored data upon request from the processor (310).

[0067] The transceiver (305) can perform functions for transmitting and receiving signals via a wireless channel. For example, the transceiver (305) can perform a conversion function between a baseband signal and a bit stream according to the physical layer specifications of the system. For example, when transmitting data, the transceiver (305) can generate complex symbols by encoding and modulating a transmission bit stream. In addition, when receiving data, the transceiver (305) can restore a reception bit stream by demodulating and decoding a baseband signal. In addition, the transceiver (305) can upconvert a baseband signal into an RF (radio frequency) band signal and transmit it through an antenna, and downconvert an RF band signal received through the antenna into a baseband signal.

[0068] To this end, the transceiver (305) may include a transmitting filter, a receiving filter, an amplifier, a mixer, an oscillator, a digital to analog convertor (DAC), an analog to digital convertor (ADC), etc. In addition, the transceiver (305) may include a plurality of transmitting and receiving paths. Furthermore, the transceiver (305) may include at least one antenna array composed of a plurality of antenna elements. In terms of hardware, the transceiver (305) may be composed of a digital unit and an analog unit, and the analog unit may be composed of a plurality of sub-units according to operating power, operating frequency, etc.

[0069] The transceiver (305) transmits and receives signals as described above. Accordingly, the transceiver (305) may be referred to as a “transmitter,” a “receiver,” or a “transmitter-receiver.” In addition, in the following description, transmission and reception performed through a wireless channel, a backhaul network, an optical cable, Ethernet, or other wired path are used to mean that the processing described above is performed by the transceiver (305). According to one embodiment, the transceiver (305) may provide an interface for communicating with other nodes in the network. That is, the transceiver (305) may convert a bit string transmitted from the base station (300) to another node, for example, another access node, another base station, an upper node, a core network, etc., into a physical signal, and may convert a physical signal received from another node into a bit string.

[0070] FIG. 4 is a flowchart illustrating an example of a functional configuration of a radio access network (RAN) controller according to various embodiments.

[0071] The terms '...bu', '...gi', etc. used below mean a unit that processes at least one function or operation, and this can be implemented by hardware, software, or a combination of hardware and software.

[0072] Referring to FIG. 4, a RAN controller (450) (e.g., RAN controller (250) of FIG. 2) may include a processor (451), a memory (453), and a transceiver (455).

[0073] The processor (451) controls the overall operations of the RAN controller (450). For example, the processor (451) writes and reads data to and from the memory (453). In addition, the processor (451) transmits and receives signals via the transceiver (455). Although FIG. 4 illustrates one processor, the embodiments of the present disclosure are not limited thereto. The RAN controller (450) may include at least one processor to perform the embodiments of the present disclosure. The processor (451) may be referred to as a control unit or control means. According to embodiments, the processor (451) may control the device to perform the operations of the RAN controller according to the embodiments of the present disclosure.

[0074] The memory (453) stores data such as basic programs, application programs, and configuration information for the operation of the RAN controller. The memory (453) may be composed of volatile memory, nonvolatile memory, or a combination of volatile and nonvolatile memory. In addition, the memory (453) provides stored data upon request from the processor (451).

[0075] The transceiver (455) may provide an interface for communicating with other devices (e.g., a base station) within the network. That is, the transceiver (455) may convert a bit stream transmitted from a core network device to another device into a physical signal, and may convert a physical signal received from another device into a bit stream. That is, the transceiver (455) may transmit and receive signals. Accordingly, the transceiver (455) may be referred to as a modem, a transmitter, a receiver, or a transceiver. In this case, the transceiver (455) enables the RAN controller (450) to communicate with other devices or systems via a backhaul connection (e.g., a wired backhaul or a wireless backhaul) or via the network.

[0076] FIG. 5 is a system diagram showing examples of measurement reports and CGI reports in a wireless communication system according to various embodiments.

[0077] The wireless communication system may include a user terminal (510) (e.g., an electronic device (101) of FIG. 1, a user terminal (210) of FIG. 2), a first base station (521) (e.g., a first base station (210) of FIG. 2, a base station (300) of FIG. 3), a second base station (522) (e.g., a second base station (211) of FIG. 2, a base station (300) of FIG. 3), and a RAN controller (not shown) (e.g., a RAN controller (250) of FIG. 2, a RAN controller (450) of FIG. 4).

[0078] The user terminal (510) can access a wireless network provided through the first base station (521) and perform communication. The user terminal (510) can connect to the network by using the first cell provided by the first base station (521) as a serving cell.

[0079] In operation (S501), the first base station (521) may transmit a measurement configuration to the user terminal (510) via the first cell. The user terminal (510) may receive the measurement configuration from the first base station (521). For example, the first base station (521) may transmit an RRC connection reconfiguration message to the user terminal (510). The RRC connection reconfiguration message may include a measurement configuration. The measurement configuration may include information for configuring (e.g., specifying, setting) measurements performed by the user terminal (510). The measurement configuration may support intra-frequency mobility, inter-frequency mobility, or inter-RAT mobility.

[0080] The measurement configuration may include measurement object information. The measurement object information may include information related to a cell for measurement. In one embodiment, the measurement object information may include a cell list. The cell list may include a neighboring cell list of the first base station (521). Within the neighboring cell list, each cell may be identified by a physical cell identity (PCI).

[0081] A measurement configuration may include a report configuration. The report configuration may include information related to criteria for triggering a measurement report. In one embodiment, the report configuration may include at least one of a trigger type, configuration information regarding a trigger condition, a trigger quantity, a report quantity, a reporting interval, a report amount indicating the number of measurement reports, or a maximum number of cells to be included in a measurement report.

[0082] The trigger type may indicate periodic measurement reporting or event-based measurement reporting. For periodic measurement reporting, configuration information regarding trigger conditions may include information indicating a purpose. For event-based measurement reporting, configuration information regarding trigger conditions may include a hysteresis value, a time-to-trigger (TTT) value, an event type, and parameters required by the event type (e.g., a threshold). The trigger quantity indicates a parameter for evaluating the trigger condition. The report quantity indicates the parameters to be included in the measurement report. The report cycle indicates the interval between measurement reports.

[0083] In operation S502, the user terminal (510) may transmit a measurement report to the first base station (521). The first base station (521) may receive the measurement report from the user terminal (510). The user terminal (510) may perform measurement on one or more cells based on an RRC connection reconfiguration message. The user terminal (510) may obtain a measurement result based on the measurement. The user terminal (510) may transmit a measurement report including the measurement result to the first base station (521). According to one embodiment, the measurement report may include measurement information on a serving cell of the user terminal (510). The measurement information on the serving cell may include signal quality (e.g., RSRP, RSRQ, SINR) for a signal (e.g., CRS) of the serving cell.

[0084] According to one embodiment, the measurement report may include measurement information for at least one neighboring cell of the user terminal (510). The measurement information for the neighboring cell may include at least one of the PCI of the neighboring cell or a measurement result of the neighboring cell. The measurement result of the neighboring cell may include signal quality (e.g., RSRP, RSRQ, SINR) for a signal (e.g., CRS) of the neighboring cell.

[0085] In operation (S503), the first base station (521) can compare the neighboring cells of the user terminal (510) included in the measurement report with the neighboring cell list of the first base station (521). The neighboring cell list of the first base station (521) can mean a list of cells provided by base stations around the first base station (521). The first base station (521) can determine whether, among the neighboring cells of the user terminal (510) included in the measurement report, there is a cell that is not included in the neighboring cell list of the first base station (521). If there is a cell (or measurement information for a cell) that is not included in the neighboring cell list of the first base station (521) in the measurement report, the first base station (521) can transmit a cell global identification configuration (CGI configuration) for the corresponding cell to the user terminal (510).

[0086] In operation (S504), the first base station (521) can transmit the CGI configuration to the user terminal (510). The user terminal (510) can receive the CGI configuration from the first base station (521).

[0087] The CGI configuration may include information for CGI measurement. The CGI may include at least one of a cell identifier (ID), a tracking area code (TAC), or a public land mobile network (PLMN).

[0088] For example, the CGI configuration may include a configuration of connected discontinuous reception (CDRX) or a configuration of a measurement gap. Each of the CDRX-based technology and the measurement gap-based technology may refer to a technique available to the user terminal (510) for CGI measurement. The measurement gap-based technology may refer to a technology in which the user terminal (510) stops data transmission during the measurement gap and performs CGI measurement of a neighboring cell. The CDRX-based technology may refer to a technology that maintains a communication channel with a serving cell in the on duration, deactivates the communication channel with the serving cell in the off duration (e.g., suspends data transmission and reception with the first base station (521) through the serving cell), and measures CGI by using a DRX cycle including an on duration (e.g., an activation period, DRX awake mode) and an off duration (e.g., a deactivation period, DRX sleep mode).

[0089] The configuration of CDRX may include, for example, a DRX inactivity timer, an on duration timer, and a DRX cycle length. In various embodiments of the present disclosure, the CGI configuration mainly describes measuring CGI via CDRX.

[0090] In operation (S505), the user terminal (510) may measure the CGI of the second base station (522) while data transmission and reception with the first base station (521) is stopped by entering an off-duration (e.g., an inactive period) during a DRX cycle. The user terminal (510) may obtain (e.g., receive, measure) a master information block (MIB) and system information blocks (SIBs) (e.g., at least one of SIB1 to SIB14) of the second cell provided by the second base station (522) from the second base station (522). The user terminal (510) may obtain a PLMN, a LAC, and a cell identifier of the second cell by decoding the MIB and SIBs of the second cell. The user terminal (510) may generate a CGI report including CGI information of the second cell based on the obtained PLMN, LAC, and cell identifier of the second cell.

[0091] In operation (S506), the user terminal (510) can transmit a CGI report to the first base station (521). The first base station (521) can receive the CGI report from the user terminal (510).

[0092] In operation (S507), the first base station (521) can update the neighboring cell list of the first base station (521) based on the CGI report. The first base station (521) can add information about the second cell provided by the second base station (522) to the neighboring cell list of the first base station (521) using the information included in the CGI report.

[0093] Although not explicitly shown in FIG. 5, the first base station (521) may transmit information based on the measurement report and CGI report received from the user terminal (510) to the RAN controller. The RAN controller may determine to switch the serving cell of the user terminal (510) from the first cell provided by the first base station (521) to the second cell provided by the second base station (522) based on the measurement report and / or CGI report received from the first base station (521). In various embodiments of the present disclosure, switching the serving cell of the user terminal (510) from the first cell to the second cell may also be expressed as a handover. If the current serving cell of the user terminal (510) (e.g., the first cell) is not an optimal cell, the user terminal (510) needs to connect to another cell (e.g., the second cell). According to various embodiments of the present disclosure, candidate cells of the user terminal (510) may be determined by the judgment of a RAN controller (e.g., a Near-RT RIC or a Non-RT RIC). If the highest priority cell among the candidate cells is not the current serving cell, the RAN controller may change the serving cell of the user terminal (510) through the first base station (521). As will be described in more detail below, the first base station (521) may transmit a handover command to the user terminal (510) to handover to the highest priority cell. In various embodiments of the present disclosure, a cell to be designated as the serving cell of the user terminal (510) through handover in the handover command may be expressed as a target cell.

[0094] The RAN controller may transmit a handover command to the first base station (521) for switching the serving cell of the user terminal (510) from the first cell to the second cell. The first base station (521) may receive a handover command from the RAN controller for switching the serving cell of the user terminal (510) from the first cell to the second cell.

[0095] The first base station (521) may transmit a handover command to the user terminal (510). According to one embodiment, the first base station (521) may transmit an RRC connection reconfiguration message including mobility control information to the user terminal (510). The mobility control information may include at least one of a PCI of a target cell (e.g., a second cell), a carrier frequency, a handover timer (e.g., a T304 timer), a Radio Network Temporary Identifier (RNTI) of the UE, or a radio resource configuration.

[0096] FIG. 6 is a diagram illustrating an example of a case in which a handover fails in a wireless communication system according to various embodiments.

[0097] A wireless communication system may include a user terminal (e.g., an electronic device (101) of FIG. 1, a user terminal (210) of FIG. 2, a user terminal (510) of FIG. 5), a first base station (e.g., a first base station (220) of FIG. 2, a base station (300) of FIG. 3, a first base station (521) of FIG. 5), and a second base station (e.g., a second base station (221) of FIG. 2, a second base station (522) of FIG. 5). The first base station may provide a macro cell, and the macro cell provided by the first base station may function as a serving cell of the user terminal.

[0098] The user terminal can generate a measurement report including measurement information for a femto cell provided by a second base station and transmit the generated measurement report to the first base station. The first base station can transmit a CGI configuration for a femto cell that is not included in the neighboring cell list of the first base station to the user terminal. The CGI configuration can instruct that CGI measurement for the femto cell be performed via CDRX.

[0099] The user equipment may measure the CGI of the femtocell while in DRX sleep mode, depending on the CGI configuration. However, the user equipment may not be able to enter the DRX sleep mode. As described in more detail later in FIG. 9, for example, if data transmission and reception with the first base station via the serving cell occurs during an active period (e.g., on-duration) of each DRX cycle, stopping the data transmission and reception with the first base station in the corresponding DRX cycle may be omitted. Consequently, the user equipment may omit entering the DRX sleep mode if data transmission and reception with the first base station occurs during the active period of the DRX cycle.

[0100] Referring to FIG. 6, if the user equipment does not enter DRX sleep mode, it may be difficult to read MIBs and / or SIBs for CGI measurement. Even if the user equipment generates a CGI report and transmits the generated CGI report to the first base station after the signal quality (e.g., SINR) of the macro cell, which is the serving cell, degrades below a threshold, the user equipment may not receive a handover command from the first base station. As a result, a radio link failure of the user equipment may occur. If a call is in progress, the call may be dropped as the transmitted and received RTP (real-time transport protocol) data is lost.

[0101] In various embodiments of the present disclosure, when a user terminal decides to prioritize CGI measurement for a CGI-configured cell (e.g., a femtocell), the user terminal may enter DRX sleep mode even in a situation where DRX sleep mode is omitted (e.g., data transmission and reception with a base station occurs during an active period during a DRX cycle), thereby preventing a handover from failing due to failure to enter DRX sleep mode.

[0102] Various embodiments of the present disclosure may be applied in the following situations. Table 1 shows a portion of logs collected from a user terminal regarding a wireless communication system.

[0103] 섹섹션로그115:19:27.803 CONN_S(409)(1550) -8849 (RSRQ: -1421)15:19:27.803 (INTRA)(EARFCN:1550)(PCID:420) (RSRP:-8665), (RSRQ: -1088)15:19:27.803 (INTRA)(EARFCN:1550)(PCID:500) (RSRP:-8942), (RSRQ: -1389)15:19:27.803 (INTRA)(EARFCN:1550)(PCID:391) (RSRP:-8972), (RSRQ: -1535)215:19:27.846 RRCConnectionReconfiguration_handover15:19:27.847 S

[0409] => D

[0420] , MR / HO15:19:27.914 HO Complete L2Ack15:19:27.923 CONN_S(420)(1550) -8574 (RSRQ: -1094)15:19:31.843 CONN_S(420)(1550) -9214 (RSRQ: -1322)15:19:31.843 (INTRA)(EARFCN:1550)(PCID:409) (RSRP:-8811), (RSRQ: -915)15:19:31.843 (INTRA)(EARFCN:1550)(PCID:500) (RSRP:-9414), (RSRQ: -1011)15:19:31.843 (INTRA)(EARFCN:1550)(PCID:391) (RSRP:-9470), (RSRQ: -1570)15:19:32.040 S

[0420] => D

[0409] , MR / HO315:19:41.048 CONN_S(420)(1550) -9217 (RSRQ: -1188)15:19:41.048 (INTRA)(EARFCN:1550)(PCID:500) (RSRP:-8602), (RSRQ: -697)15:19:41.068 E-Utra CGI Rpt Config is configured415:19:41.072 PCell SINR [ 1.31 ( -1, 1, 0, 2)]15:19:41.072~15:19:42.010 Section The condition of not being able to enter CDRX Sleep is maintained, and the phenomenon is repeated thereafter, and T321 timer expiry is repeated 5 15:19:42.073 T321 Timer is completely Expierd 15:19:43.351 T321 Timer is completely Expierd 15:19:44.643 T321 Timer is completely Expierd 6 15:19:44.840 E-Utra CGI Rpt Config is configured 15:19:44.843 T321 START Current runtime 1000 15:19:44.843 CGI_SUSPENDED 15:19:45.442 At that point, CDRX sleep was entered and CGI search was in progress 15:19:45.442 CGI_SEARCHING) -15:19:45.481 T321 STOP Set:1000 ms, Remain: 362 ms15:19:45.467 [1550, 500] MasterInformationBlock15:19:45.482 CGI_REPORT)15:19:45.873 PCell SINR [-2.53 (-8, -6)], RSRQ [-12 (-12, -12)].

[0104] Section 1 of Table 1 shows information about the signal quality of the serving cell of the user terminal (e.g., the cell of PCID 409) and neighboring cells (e.g., the cell of PCID 420, the cell of PCID 500, the cell of PCID 391). Here, the cell of PCID 500 may be a cell for which CGI measurement is configured. In other words, the user terminal may have received a CGI configuration for the cell of PCID 500 from the base station providing the serving cell.

[0105] In section 2 of Table 1, if there is another handover target cell in addition to the CGI configured cell (e.g., the cell of PCID 500), measurement and handover proceed to that cell, so the user terminal may not need to prioritize the CGI measurement of the CGI configured cell (e.g., the cell of PCID 500). As shown in section 2 of Table 1, the user terminal may change the serving cell from the cell of PCID 409 to the cell of PCID 420, and then change the serving cell from the cell of PCID 420 to the cell of PCID 420, based on a handover command received from a base station providing the serving cell.

[0106] In section 3 of Table 1, the HO target cell of the user terminal may be only the cell of PCID 500, which is a CGI-configured cell. In this case, the user terminal may need to measure the CGI for the cell of PCID 500 and then change the serving cell to the cell of PCID 500.

[0107] In section 4 of Table 1, although the signal quality (e.g., SINR) of the serving cell is gradually degraded, the user terminal may not be able to enter DRX sleep mode due to data transmission / reception (e.g., UL Grant) that occurred during the active period during the DRX cycle, and thus may not be able to measure the CGI for the cell in PCID 500.

[0108] In section 5 of Table 1, the user terminal may repeatedly fail to measure CGI for a cell in PCID 500 for the same or similar reasons as in section 4 of Table 1 (e.g., UL Grant, DL Grant), and the timer corresponding to CGI measurement (e.g., T321 timer) may repeatedly expire.

[0109] In section 6 of Table 1, the UE measures the CGI for the cell in PCID 500 in response to meeting the conditions for entering DRX sleep mode at a point in time of about 5 seconds, but it may be difficult to receive a handover command even if it transmits a CGI report in a situation where the signal quality (e.g., SINR) of the serving cell has already dropped below a threshold (e.g., -5).

[0110] As will be described in more detail later in FIGS. 7 to 12, in various embodiments of the present disclosure, the user terminal may determine to prioritize CGI measurement based on the fact that the HO target cell of the user terminal is the only cell configured with CGI in Section 3 of Table 1, thereby forcibly entering DRX sleep mode unlike in Sections 4 and 5 of Table 1.

[0111] FIG. 7 is a flowchart illustrating an example of a method for preferentially processing CGI measurements in a wireless communication system according to various embodiments.

[0112] According to one embodiment, a wireless communication system may include a user terminal (710) (e.g., an electronic device (101) of FIG. 1, a user terminal (210) of FIG. 2, a user terminal (510) of FIG. 5), a first base station (721) (e.g., a first base station (220) of FIG. 2, a base station (300) of FIG. 3, a first base station (521) of FIG. 5), and a second base station (722) (e.g., a second base station (221) of FIG. 2, a second base station (522) of FIG. 5). The user terminal (710) may be connected to the network through a first cell, which is a serving cell of the user terminal (710), among a plurality of cells provided by the network. The first cell may be provided by the first base station (721).

[0113] In operation (S701), the first base station (721) can transmit a measurement configuration to the user terminal (710). The user terminal (710) can receive the measurement configuration from the first base station (721).

[0114] In operation (S702), the user terminal (710) can generate a measurement report for a cell provided by a base station around the user terminal (710) when an event corresponding to a measurement report (e.g., A1 event, A2 event, A3 event, A4 event, A5 event) occurs.

[0115] In operation (S703), the user terminal (710) can transmit the generated measurement report to the first base station (721). The first base station (721) can receive the generated measurement report from the user terminal (710).

[0116] In operation (S704), the first base station (721) may transmit a cell global identity configuration (CGI) for the second cell to the user terminal (710). As described above in FIG. 5, the first base station (721) may transmit the CGI configuration for the second cell based on the result of comparing the neighboring cell list of the first base station (721) with the cell indicated in the measurement report. The second cell may be a cell that is not included in the neighboring cell list of the first base station (721) among the cells indicated in the measurement report. The user terminal (710) may receive the CGI configuration for the second cell from the first base station (721).

[0117] In operation (S705), the user terminal (710) can check whether a condition for prioritizing CGI measurement is satisfied when CGI measurement via DRX (discontinuous reception) is configured in the CGI configuration for the received second cell. The DRX may include, for example, CDRX (connected DRX). The condition for prioritizing CGI measurement may include a condition for detecting a situation in which a handover is likely to fail or a communication error of the user terminal (710) is likely to occur if CGI measurement for the second cell is not forcibly performed. The condition for prioritizing CGI measurement is described in more detail below with reference to FIG. 8.

[0118] In operation (S706), the user terminal (710) may stop transmitting and receiving data with the first base station (721) in at least one of the DRX cycles that are periodically repeated according to the DRX based on the condition being met. Each DRX cycle may include an activation period and an inactivity period following the activation period. The activation period may refer to a period of time for maintaining a communication channel with the first base station (721). In the activation period, the user terminal (710) may receive data from the first base station (721) or transmit data to the first base station (721). In the inactivity period, the user terminal (710) may stop (e.g., block) transmitting and receiving data with the first base station (721).

[0119] The user terminal (710) may skip the inactive period of the DRX cycle if data is received from the first base station (721) (e.g., downlink grant (DL grant)) and / or data is transmitted to the first base station (721) (e.g., uplink grant (UL grant)) during the active period of each DRX cycle. However, as described in more detail later in FIGS. 8 to 12, if a condition for giving priority to CGI measurement is satisfied, the user terminal (710) may enter the DRX sleep mode by stopping data transmission and reception with the first base station (721) upon satisfying an additional condition for forcing stopping of data transmission and reception with the first base station (721).

[0120] In operation (S707), the user terminal (710) may generate a CGI report for the second cell based on information received from the second base station (722) providing the second cell while data transmission and reception with the first base station (721) is suspended (e.g., during a DRX sleep mode, during an inactive period during a DRX cycle). As described above in FIG. 5, the user terminal (710) may obtain MIB and SIB(s) for the second cell from the second base station (722) and measure the CGI for the second cell by decoding the obtained MIB and SIB(s).

[0121] In operation (S708), the user terminal (710) may transmit the generated CGI report to the first base station (721). The first base station (721) may receive the CGI report for the second cell from the user terminal (710). Although not explicitly shown in FIG. 7, the first base station (721) may transmit the measurement report and the CGI report to a RAN controller (not shown). The RAN controller may determine to change the serving cell of the user terminal (710) from the first cell to the second cell based on at least one of the measurement report or the CGI report received from the first base station (721). The RAN controller may transmit a handover command to the first base station (721) to switch the serving cell of the user terminal (710) from the first cell to the second cell. The first base station (721) may receive the handover command from the RAN controller.

[0122] In operation (S709), the first base station (721) may transmit a handover command to the user terminal (710) to change the serving cell of the user terminal (710) from the first cell to the second cell. The user terminal (710) may receive the handover command from the first base station (721).

[0123] In operation (S710), the user terminal (710) can switch the serving cell from the first cell to the second cell based on the handover command.

[0124] In operation (S711), the user terminal (710) may transmit a handover confirm to the second base station (722) providing the second cell based on the switching of the serving cell from the first cell to the second cell. The second base station (722) may receive the handover confirm indicating that the handover to the second cell has been completed from the user terminal (710).

[0125] FIG. 8 is a diagram illustrating an example of an operation for determining whether a condition for a user terminal to give priority to CGI measurement is satisfied in a wireless communication system according to various embodiments.

[0126] According to one embodiment, a user terminal (e.g., electronic device (101) of FIG. 1, user terminal (210) of FIG. 2, user terminal (510) of FIG. 5, user terminal (710) of FIG. 7) can check whether a condition for giving priority to CGI measurement is satisfied.

[0127] In one embodiment, a condition for prioritizing CGI measurements may include that the user terminal performs real-time packet data communication (e.g., voice call, video call, streaming) over a network.

[0128] In one embodiment, the condition for prioritizing CGI measurements may include that no other cell exists among the cells described in the generated measurement report other than the second cell. For example, the condition for prioritizing CGI measurements may include that no cell included in the neighboring cell list of the first base station exists in the measurement report. If no non-CGI-configured cell exists in the measurement report (e.g., if only CGI-configured cells exist in the measurement report), it may be necessary to prioritize CGI measurements for the second cell in order to handover to the CGI-configured second cell. Conversely, if another cell exists in the neighboring cell list of the first base station in the measurement report, handover to another cell included in the neighboring cell list may be possible even if CGI measurements for the second cell are not performed, and thus the CGI measurements may not be prioritized.

[0129] According to one embodiment, a condition for giving priority to CGI measurement may include that the signal quality (e.g., RSRP, RSRQ, SINR) of a signal received from the first base station through the first cell is lower than a first threshold quality, and no cell among the neighboring cell list of the first base station provides a signal having a signal quality higher than or equal to a second threshold quality. The second threshold quality may be determined based on a trigger condition of an A3 event. For example, the second threshold quality may be determined as a value obtained by applying an offset (e.g., adding or subtracting) to the signal quality of a signal received from the first base station through the first cell (e.g., the signal quality of a serving cell). In this case, a cell providing a signal having a signal quality higher than or equal to the second threshold quality may refer to a cell that satisfies the trigger condition of an A3 event.

[0130] According to one embodiment, a user terminal may determine whether a condition for prioritizing CGI measurement is satisfied based on at least one of a plurality of sub-conditions included in a condition. The plurality of sub-conditions may include that the user terminal performs real-time packet data communication through a network, that no other cell exists among the cells described in the measurement report other than the second cell, and that the signal quality of a signal received from the first base station through the first cell is lower than a first threshold quality and that no cell provides a signal having a signal quality higher than the second threshold quality among the cells included in the neighboring cell list of the first base station.

[0131] Referring to FIG. 8, in operation (810), the user terminal can determine whether the user terminal is performing real-time packet data communication. If the user terminal is not performing real-time communication with another user terminal (e.g., if 'No' in operation (810)), the user terminal can determine that the condition for prioritizing CGI measurement is not met. If the user terminal is performing real-time packet data communication (e.g., if 'Yes' in operation (810)), the user terminal can check whether other partial conditions are met.

[0132] In operation (820), the user terminal can check whether there is no other cell other than the second cell among the cells set in the measurement report when the user terminal is performing real-time packet data communication. If there is no other cell other than the second cell among the cells described in the measurement report (e.g., 'Yes' in operation (820)), the user terminal can determine that the condition for prioritizing CGI measurement is satisfied. If there is another cell other than the second cell among the cells described in the measurement report (e.g., 'No' in operation (820)), the user terminal can check whether other partial conditions are satisfied.

[0133] In operation (830), the user terminal may determine whether the signal quality of the signal received through the first cell is lower than the first threshold quality and whether there is no cell among the cells included in the neighboring cell list of the first base station that provides a signal having a signal quality higher than the second threshold quality. If the signal quality of the signal received through the first cell is lower than the first threshold quality and there is no cell among the cells included in the neighboring cell list of the first base station that provides a signal having a signal quality higher than the second threshold quality (e.g., if 'Yes' in operation (830)), the user terminal may determine that the condition for preferentially processing the CGI measurement is satisfied. If the signal quality of the signal received through the first cell is higher than the first threshold quality or there is a cell among the cells included in the neighboring cell list of the first base station that provides a signal having a signal quality higher than the second threshold quality (e.g., 'No' in operation (830)), the user terminal may determine that the condition for preferentially processing the CGI measurement is not satisfied.

[0134] In operation (840), the user terminal may determine that a condition for prioritizing CGI measurement is satisfied. The user terminal may determine that the condition is satisfied based on the results confirmed in the aforementioned operations (810, 820, 830). As will be described in more detail later with reference to FIGS. 9 to 12, the user terminal may force entry into DRX sleep mode in at least one of the DRX cycles based on the condition being satisfied, thereby at least substantially ensuring that the CGI of the second cell is measured while data transmission and reception with the first base station is suspended.

[0135] In operation (850), the user terminal may determine that the condition for prioritizing CGI measurements is not met. The user terminal may determine that the condition is not met based on the results confirmed in operations (810, 820, 830) described above.

[0136] In operation (860), if the user equipment determines that the condition for prioritizing CGI measurement is not met, the user equipment may attempt to measure CGI according to the DRX standard. For example, if no data transmission or reception with the first base station occurs during the active period of the DRX cycle, the user equipment may enter DRX sleep mode and attempt to measure the CGI of the second cell. If data transmission or reception with the first base station occurs during the active period of the DRX cycle, the user equipment may skip entering DRX sleep mode and delay measuring the CGI of the second cell to a subsequent DRX cycle (e.g., the next DRX cycle). However, if the user equipment does not enter DRX sleep mode in all DRX cycles until the timer for CGI measurement (e.g., T321 timer) expires, the user equipment may fail to measure the CGI of the second cell.

[0137] FIG. 9 is a diagram illustrating an example of an operation of a user terminal switching between activating and deactivating communication with a first base station according to a DRX cycle according to various embodiments.

[0138] Referring to Figure 9, a system frame, as a time unit in a wireless communication system, can be used to manage time. The SFN (system frame number) may refer to the number of a system frame. The SFN may be used for time synchronization between elements of a wireless communication system (e.g., a first base station, a user terminal, a second base station, and a RAN controller).

[0139] Each system frame can be divided into a predetermined number of subframes (e.g., 10).

[0140] PDCCH (physical downlink control channel) is a channel that transmits data (e.g., control information) from a base station (e.g., first base station) to a user terminal, and can indicate that data is transmitted in a specific subframe.

[0141] A DRX inactivity timer may refer to a timer that sets a waiting time when no additional data is received after the user equipment receives data (e.g., a data packet) from a base station (e.g., a first base station). The user equipment may start a DRX cycle if no additional data is received before the DRX inactivity timer expires. The user equipment may enter a DRX cycle after a predetermined number of subframes (e.g., 1) after the DRX inactivity timer expires.

[0142] A user terminal may start a DRX cycle based on a DRX start offset (e.g., DRX start offset). For example, the DRX start offset may be set to 0.

[0143] A DRX cycle may be classified into multiple types. For example, a DRX cycle may be classified into one of multiple types including a first type (e.g., a short type) and a second type (e.g., a long type). A length (e.g., a number of subframes) of a DRX cycle of the first type (e.g., a short DRX cycle) may be determined based on a variable (e.g., ShortDrxCycle) defining a length of a cycle corresponding to the first type. For example, a length of a DRX cycle of the first type may be determined as 6 subframes. A length (e.g., a number of subframes) of a DRX cycle of the second type (e.g., a long DRX cycle) may be determined based on a variable (e.g., LongDrxCycle) defining a length of a cycle corresponding to the second type. For example, the length of the second type of DRX cycle may be determined as 12 subframes. The user equipment may repeat the first type of DRX cycle(s) based on a timer (e.g., DrxShortCycleTimer timer) defining the number of the first type of DRX cycles, and thereafter repeat the second type of DRX cycle(s). Referring to FIG. 9, for example, the DrxShortCycleTimer timer may be set to 2. The user equipment may repeat the first type of DRX cycle twice, and thereafter repeat the second type of DRX cycle. The user equipment may control activation and deactivation of communication with the first base station according to the first short DRX cycle (911) and the second short DRX cycle (912), and then control activation and deactivation of communication with the first base station according to the first long DRX cycle (921).

[0144] An on duration timer may refer to a timer that sets a length (e.g., the number of subframes) of an activated period of a user equipment during each DRX cycle (e.g., a first type of DRX cycle, a second type of DRX cycle). Referring to FIG. 9, for example, the on duration timer may be set to two subframes. Each DRX cycle may include an activation period for two subframes and an inactivation period for the remaining subframes among the length of the corresponding DRX cycle. The first type of DRX cycle may include an activation period for two subframes and an inactivation period for four subframes. The second type of DRX cycle may include an activation period for two subframes and an inactivation period for ten subframes.

[0145] The user equipment may determine whether to enter DRX sleep mode in the DRX cycle during an active period of each DRX cycle. The user equipment entering DRX sleep mode in the DRX cycle may mean stopping data transmission and reception with the first base station in at least one subframe included in the DRX cycle.

[0146] The user equipment may skip suspending data transmission and reception with the first base station in the DRX cycle based on transmitting data to or receiving data from the first base station during the active period of each DRX cycle. In other words, the user equipment may skip entering the DRX sleep mode in the DRX cycle based on transmitting and receiving data with the first base station during the active period of each DRX cycle. As a result, the user equipment may not suspend data transmission and reception with the first base station in the DRX cycle.

[0147] Referring to FIG. 9, the user terminal may receive data from the first base station during an activation period (922) of a second long DRX cycle subsequent to a first long DRX cycle (921). Based on receiving data from the first base station during the activation period (922), the user terminal may omit entering a DRX sleep mode in the second long DRX cycle and / or suspending data transmission and reception with the first base station during the second long DRX cycle. The user terminal may maintain communication with the first base station in an activated state in subframes subsequent to the activation period (922).

[0148] If entering DRX sleep mode is omitted due to data transmission and reception with the first base station during each activation period of all DRX cycles, the user terminal may not stop data transmission and reception with the first base station, and as a result, may not be able to measure the CGI of the second cell of the second base station.

[0149] In one embodiment, a user equipment (UE) may force entry into DRX sleep mode in certain circumstances when prioritizing CGI measurement. The UE may determine whether an additional condition for forcing the discontinuation of data transmission and reception with a first base station in each DRX cycle is satisfied when a condition for prioritizing CGI measurement is satisfied. If the additional condition is satisfied, the UE may discontinue data transmission and reception independently from data transmission and reception during an active period of the DRX cycle. For example, the UE may discontinue data transmission and reception during at least a portion of the DRX cycle (e.g., an inactive period) even if data transmission and reception with the first base station occurs during the active period of the DRX cycle. The additional condition may be satisfied based on at least one of a type of DRX cycle, the number of times entering DRX sleep mode has been skipped, or a timer for CGI measurement. The additional condition is described in more detail below with reference to FIGS. 10 to 12 .

[0150] When the user terminal attempts to measure the CGI of the second cell while in DRX sleep mode, depending on whether additional conditions are met, the CGI measurement may succeed or fail. If the CGI measurement fails, the user terminal may check whether the additional conditions are met until the CGI measurement succeeds, and in response to the additional conditions being met, enter DRX sleep mode and attempt to measure the CGI.

[0151] FIG. 10 is a diagram illustrating an example of an operation forcing a user terminal to stop transmitting and receiving data with a first base station based on a type of DRX cycle according to various embodiments.

[0152] According to one embodiment, an additional condition for forcing the discontinuation of data transmission and reception with the first base station may include that the cycle type of the current DRX cycle is a predetermined type. When a DRX cycle of the predetermined type (e.g., a second type, a long type) starts, the user equipment may be forced to enter a DRX sleep mode and / or discontinue data transmission and reception with the first base station in the corresponding DRX cycle. When a specific DRX cycle of the second type starts, the user equipment may stop data transmission and reception with the first base station for at least a portion (e.g., an inactive period) of the specific DRX cycle, even if the user equipment received data from or transmitted data to the first base station in an active period of the specific DRX cycle, and measure a CGI of the second cell of the second base station.

[0153] Referring to FIG. 10, a user equipment may activate or deactivate data transmission and reception with a first base station according to a second type of DRX cycles following a predetermined number of first type of DRX cycles (not shown). For example, the length of the second type of DRX cycle may be set to 160 ms, and the duration of a timer (e.g., T321 timer) for CGI measurement may be set to 1000 ms. The user equipment may stop data transmission and reception with the first base station during at least a portion (1012) of the first DRX cycle (1010), independently of data transmission and reception during an activation period (1011) of the first DRX cycle (1010), based on the first DRX cycle (1010) being of the second type. The user terminal may measure the CGI of the second cell during an inactive period (e.g., at least a portion (1012)) of the first DRX cycle (1010).

[0154] FIG. 11 is a diagram illustrating an example of an operation forcing a user terminal to stop transmitting and receiving data with a first base station based on omitting to enter a DRX sleep mode in a DRX cycle according to various embodiments.

[0155] In one embodiment, an additional condition for forcing the cessation of data transmission and reception with the first base station may include repeating the omission of cessation of data transmission and reception with the first base station a predetermined number of times in succession in a DRX cycle.

[0156] As described above in FIG. 9, when the user equipment receives data from or transmits data to the first base station during an active period of a DRX cycle, the user equipment may omit entering the DRX sleep mode and / or stopping data transmission and reception with the first base station in the DRX cycle. When the user equipment continuously repeats stopping data transmission and reception with the first base station (e.g., entering the DRX sleep mode) a predetermined number of times in a DRX cycle, the user equipment may be forced to enter the DRX sleep mode and / or stop data transmission and reception with the first base station for at least a portion of the subsequent DRX cycle even if the user equipment receives data from or transmits data to the first base station during the active period of the subsequent DRX cycle.

[0157] Referring to FIG. 11, the length of a DRX cycle may be set to 160 ms, for example, and the duration of a timer (e.g., T321 timer) for CGI measurement may be set to 1000 ms. An additional condition may include repeating three consecutive times the omission of stopping data transmission and reception with the first base station in the DRX cycle. The user equipment may omit stopping data transmission and reception with the first base station in the first DRX cycle (1110) based on receiving data from or transmitting data to the first base station in the active period of the first DRX cycle (1110). Similarly, the user equipment may omit stopping data transmission and reception with the first base station in each of the second DRX cycle (1120) and the third DRX cycle (1130) based on receiving data from or transmitting data to the first base station in the active period of the corresponding DRX cycle. As a result, as shown in FIG. 11, the user terminal may omit entering the DRX sleep mode and / or stopping data transmission and reception with the first base station in the first DRX cycle (1110), the second DRX cycle (1120), and the third DRX cycle (1130). The user terminal may force entering the DRX sleep mode and / or stopping data transmission and reception with the first base station in the fourth DRX cycle (1140) following the third DRX cycle (1130). For example, even if the user terminal received data from the first base station or transmitted data to the first base station in the activation period (1141) of the fourth DRX cycle (1140), the user terminal may stop data transmission and reception with the first base station in at least a part (1142) of the fourth DRX cycle (1140). The user terminal may measure the CGI of the second cell during an inactive period (e.g., at least a portion (1142)) of the fourth DRX cycle (1140).

[0158] FIG. 12 is a diagram illustrating an example of an operation forcing a user terminal to stop transmitting and receiving data with a first base station based on a timer for CGI measurement according to various embodiments.

[0159] According to one embodiment, an additional condition for forcing the cessation of data transmission and reception with the first base station may include that the current DRX cycle is the last DRX cycle before the expiry of a timer for CGI measurement.

[0160] As described above in FIG. 9, if the user equipment receives data from or transmits data to the first base station during the active period of the DRX cycle, the user equipment may omit entering the DRX sleep mode and / or ceasing data transmission and reception with the first base station in the DRX cycle. If the user equipment repeatedly suspends data transmission and reception with the first base station (e.g., enters the DRX sleep mode) in the DRX cycle, the last DRX cycle may start before the timer for CGI measurement (e.g., T321 timer) expires while the user equipment has not measured the CGI. In this case, the user equipment may be forced to enter the DRX sleep mode and / or ceasing data transmission and reception with the first base station in at least a part of the subsequent DRX cycle even if the user equipment received data from or transmitted data to the first base station during the active period of the last DRX cycle.

[0161] Referring to FIG. 12, the length of a DRX cycle may be set to 160 ms, for example, and the duration of a timer (e.g., T321 timer) for CGI measurement may be set to 1000 ms. Within the duration of the timer for CGI measurement, DRX cycles may be repeated 6 times.

[0162] The user terminal may omit stopping data transmission and reception with the first base station in the first DRX cycle (1210) based on receiving data from or transmitting data to the first base station during an active period in the first DRX cycle (1210). Similarly, the user terminal may omit stopping data transmission and reception with the first base station in each of the second DRX cycle (1220), the third DRX cycle (1230), the fourth DRX cycle (1240), and the fifth DRX cycle (1250) based on receiving data from or transmitting data to the first base station during the active period of the corresponding DRX cycle. As a result, as shown in FIG. 12, the user terminal may omit entering the DRX sleep mode and / or stopping data transmission and reception with the first base station in the first DRX cycle (1210), the second DRX cycle (1220), the third DRX cycle (1230), the fourth DRX cycle (1240), and the fifth DRX cycle (1250).

[0163] The user equipment may not have measured the CGI before the start of the 6th DRX cycle (1260). The user equipment may stop transmitting and receiving data with the first base station for at least a portion (1262) of the 6th DRX cycle (1260) based on the fact that the current DRX cycle is the last DRX cycle (e.g., the 6th DRX cycle (1260)) before the timer for CGI measurement expires and the user equipment has not measured the CGI. Even if the user equipment received or transmitted data from the first base station during the active period (1261) of the 6th DRX cycle (1260), the user equipment may stop transmitting and receiving data with the first base station and measure the CGI of the second cell during the inactive period (e.g., at least a portion (1262)) of the 6th DRX cycle (1260).

[0164] Electronic devices according to the various embodiments disclosed in this document may take various forms. Electronic devices may include, for example, portable communication devices (e.g., smartphones), computer devices, portable multimedia devices, portable medical devices, cameras, wearable devices, or home appliances. Electronic devices according to the embodiments of this document are not limited to the aforementioned devices.

[0165] The various embodiments of this document and the terminology used therein are not intended to limit the technical features described in this document to specific embodiments, but should be understood to include various modifications, equivalents, or substitutes of the embodiments. In connection with the description of the drawings, similar reference numerals may be used for similar or related components. The singular form of a noun corresponding to an item may include one or more of the items, unless the context clearly indicates otherwise. In this document, each of the phrases "A or B", "at least one of A and B", "at least one of A or B", "A, B, or C", "at least one of A, B, and C", and "at least one of A, B, or C" can include any one of the items listed together in the corresponding phrase among those phrases, or all possible combinations thereof. Terms such as "first," "second," or "first" or "second" may be used merely to distinguish one component from another, and do not limit the components in any other respect (e.g., importance or order). When a component (e.g., a first component) is referred to as "coupled" or "connected" to another component (e.g., a second component), with or without the terms "functionally" or "communicatively," it means that the component can be connected to the other component directly (e.g., wired), wirelessly, or through a third component.

[0166] The term "module" used in various embodiments of this document may include a unit implemented in hardware, software, or firmware, and may be used interchangeably with terms such as logic, logic block, component, or circuit. A module may be an integral component, or a minimum unit or part of such a component that performs one or more functions. For example, according to one embodiment, a module may be implemented in the form of an application-specific integrated circuit (ASIC).

[0167] Various embodiments of the present document may be implemented as software (e.g., a program (140)) including one or more instructions stored in a storage medium (e.g., an internal memory (136) or an external memory (138)) readable by a machine (e.g., an electronic device (101)). For example, a processor (e.g., a processor (120)) of the machine (e.g., an electronic device (101)) may call at least one instruction among the one or more instructions stored from the storage medium and execute it. This enables the machine to operate to perform at least one function according to the at least one called instruction. The one or more instructions may include code generated by a compiler or code executable by an interpreter. The machine-readable storage medium may be provided in the form of a non-transitory storage medium. Here, 'non-transitory' simply means that the storage medium is a tangible device and does not contain signals (e.g., electromagnetic waves), and the term does not distinguish between cases where data is stored semi-permanently or temporarily on the storage medium.

[0168] According to one embodiment, the method according to various embodiments disclosed in the present document may be provided as included in a computer program product. The computer program product may be traded as a product between a seller and a buyer. The computer program product may be distributed in the form of a machine-readable storage medium (e.g., compact disc read-only memory (CD-ROM)), or may be distributed online (e.g., downloaded or uploaded) via an application store (e.g., Play Store™) or directly between two user devices (e.g., smart phones). In the case of online distribution, at least a portion of the computer program product may be temporarily stored or temporarily generated in a machine-readable storage medium, such as the memory of a manufacturer's server, an application store's server, or an intermediary server.

[0169] According to various embodiments, each component (e.g., a module or a program) of the above-described components may include one or more entities, and some of the entities may be separated and placed in other components. According to various embodiments, one or more components or operations of the aforementioned components may be omitted, or one or more other components or operations may be added. Alternatively or additionally, a plurality of components (e.g., a module or a program) may be integrated into a single component. In such a case, the integrated component may perform one or more functions of each of the plurality of components identically or similarly to those performed by the corresponding component among the plurality of components prior to the integration. According to various embodiments, the operations performed by a module, program, or other component may be executed sequentially, in parallel, iteratively, or heuristically, or one or more of the operations may be executed in a different order, omitted, or one or more other operations may be added.

[0170] The embodiments described above may be implemented using hardware components, software components, and / or a combination of hardware components and software components. For example, the devices, methods, and components described in the embodiments may be implemented using a general-purpose computer or a special-purpose computer, such as, for example, a processor, a controller, an arithmetic logic unit (ALU), a digital signal processor, a microcomputer, a field programmable gate array (FPGA), a programmable logic unit (PLU), a microprocessor, or any other device capable of executing instructions and responding to them. The processing device may execute an operating system (OS) and software applications running on the operating system. Furthermore, the processing device may access, store, manipulate, process, and generate data in response to the execution of the software. For ease of understanding, the processing device is sometimes described as being used alone; however, one of ordinary skill in the art will recognize that the processing device may include multiple processing elements and / or multiple types of processing elements. For example, a processing unit may include multiple processors, or a processor and a controller. Other processing configurations, such as parallel processors, are also possible.

[0171] Software may include computer programs, codes, instructions, or a combination of one or more of these, which may configure a processing device to perform a desired operation or may independently or collectively command the processing device. The software and / or data may be permanently or temporarily embodied in any type of machine, component, physical device, virtual equipment, or computer storage medium or device for interpretation by the processing device or for providing instructions or data to the processing device. The software may also be distributed over networked computer systems and stored or executed in a distributed manner. The software and data may be stored on a computer-readable recording medium.

[0172] The method according to the embodiment may be implemented in the form of program commands that can be executed through various computer means and recorded on a computer-readable medium. The computer-readable medium may include program commands, data files, data structures, etc., alone or in combination, and the program commands recorded on the medium may be those specially designed and configured for the embodiment or may be known and available to those skilled in the art of computer software. Examples of the computer-readable recording medium include magnetic media such as hard disks, floppy disks, and magnetic tapes, optical media such as CD-ROMs and DVDs, magneto-optical media such as floptical disks, and hardware devices specially configured to store and execute program commands such as ROMs, RAMs, and flash memories. Examples of program commands include not only machine language codes such as those generated by a compiler, but also high-level language codes that can be executed by a computer using an interpreter, etc.

[0173] The hardware devices described above may be configured to operate as one or more software modules to perform the operations of the embodiments, and vice versa.

Claims

1. In the user terminal (101; 210; 510; 710), A communication circuit connected to the network through a first cell, which is a serving cell of the user terminal (101; 210; 510; 710), among a plurality of cells provided by the network; At least one processor (120) comprising a processing circuit; and A memory (130) comprising one or more storage media for storing instructions, When the above instructions are executed by the at least one processor (120), the user terminal (101; 210; 510; 710) causes: Receive a measurement configuration from a first base station (220; 300; 521; 721) providing the first cell, When an event corresponding to a measurement report occurs, a measurement report is generated for a cell provided by a base station around the user terminal (101; 210; 510; 710), Transmit the above generated measurement report to the first base station (220; 300; 521; 721), Receive a CGI configuration (cell global identity configuration) for the second cell from the first base station (220; 300; 521; 721), When configuring CGI measurement through DRX (discontinuous reception) in the CGI configuration for the received second cell, check whether the condition for prioritizing CGI measurement is satisfied, Based on the above condition being met, stopping transmitting and receiving data with the first base station (220; 300; 521; 721) in at least one of the DRX cycles that are periodically repeated according to the DRX, While data transmission and reception with the first base station (220; 300; 521; 721) is suspended, a CGI report for the second cell is generated based on information received from the second base station (221; 522; 722) providing the second cell, Transmit the generated CGI report to the first base station (220; 300; 521; 721) To do, User terminal (101; 210; 510; 710).

2. In paragraph 1, When the above instructions are executed by the at least one processor (120), the user terminal (101; 210; 510; 710) causes: Receive a handover command from the first base station (220; 300; 521; 721) to change the serving cell from the first cell to the second cell, Switching the serving cell from the first cell to the second cell based on the handover command To do, User terminal (101; 210; 510; 710).

3. In any one of paragraphs 1 and 2, The above conditions are, The above user terminal (101; 210; 510; 710) includes performing real-time packet data communication through the network. User terminal (101; 210; 510; 710).

4. In any one of paragraphs 1 to 3, The above conditions are, Including that there is no other cell other than the second cell among the cells described in the above generated measurement report, User terminal (101; 210; 510; 710).

5. In any one of paragraphs 1 to 4, The above conditions are, The signal quality of the signal received through the first cell from the first base station (220; 300; 521; 721) is lower than the first threshold quality, and there is no cell among the cells included in the neighboring cell list of the first base station (220; 300; 521; 721) that provides a signal having a signal quality higher than the second threshold quality. User terminal (101; 210; 510; 710).

6. In any one of paragraphs 1 to 5, The second cell above, Among the cells described in the above-mentioned generated measurement report, a cell that is not included in the neighbor cell list of the first base station (220; 300; 521; 721) User terminal (101; 210; 510; 710).

7. In any one of paragraphs 1 to 6, The above instructions, when executed by the at least one processor (120), cause the user terminal (101; 210; 510; 710) to: In an active period during which a communication channel with the first base station (220; 300; 521; 721) is maintained during each DRX cycle, based on transmitting data to the first base station (220; 300; 521; 721) or receiving data from the first base station (220; 300; 521; 721), skipping the interruption of data transmission and reception with the first base station (220; 300; 521; 721) in the corresponding DRX cycle, If an additional condition for forcing the suspension of data transmission and reception with the first base station (220; 300; 521; 721) in each DRX cycle is met, the data transmission and reception is suspended independently from the data transmission and reception in the activation period of the corresponding DRX cycle. To do, User terminal (101; 210; 510; 710).

8. In any one of paragraphs 1 to 7, Additional conditions are: Including that the cycle type of the current DRX cycle is a predetermined type, User terminal (101; 210; 510; 710).

9. In any one of paragraphs 1 to 8, Additional conditions are: Including the repetition of the omission of stopping data transmission and reception with the first base station (220; 300; 521; 721) in a DRX cycle for a predetermined number of consecutive times. User terminal (101; 210; 510; 710).

10. In any one of paragraphs 1 to 9, Additional conditions are: Including that the current DRX cycle is the last DRX cycle before the expiry of the timer for the above CGI measurement, User terminal (101; 210; 510; 710).

11. In a method performed by a user terminal, An operation (S701) of receiving a measurement configuration from a first base station providing a first cell, which is a serving cell of the user terminal, among a plurality of cells provided in a network; When an event corresponding to a measurement report occurs, an operation (S702) of generating a measurement report for a cell provided by a base station around the user terminal; An operation of transmitting the generated measurement report to the first base station (S703); An operation of receiving a cell global identity configuration (CGI configuration) for a second cell from the first base station (S704); When CGI measurement through DRX (discontinuous reception) is configured in the CGI configuration for the received second cell, an operation (S705) for checking whether a condition for prioritizing CGI measurement is satisfied; An operation (S706) of stopping transmitting and receiving data with the first base station in at least one of the DRX cycles that are periodically repeated according to the DRX based on the above condition being met; An operation (S707) of generating a CGI report for the second cell based on information received from a second base station providing the second cell while data transmission and reception with the first base station is stopped; and An operation of transmitting the generated CGI report to the first base station (S708) How to include.

12. In paragraph 11, The above method, An operation (S709) of receiving a handover command from the first base station to change the serving cell from the first cell to the second cell; and Further comprising an operation (S710) of switching the serving cell from the first cell to the second cell based on the handover command. method.

13. In any one of paragraphs 11 to 12, The above conditions are, Including that the user terminal performs real-time packet data communication through the network, method.

14. In any one of paragraphs 11 to 13, The above conditions are, Including that there is no other cell other than the second cell among the cells described in the above generated measurement report, method.

15. A computer-readable recording medium storing one or more computer programs including commands for performing the method of any one of claims 11 to 14.

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