Method and apparatus for optimizing LP-wur / wus function in mobile communication system

Abstract

The present disclosure relates to a method performed by a terminal in a communication system, the method being characterized by comprising: receiving minimization of drive test (MDT) configuration information including low power-synchronization signal (LP-SS) configuration information from a base station, wherein the LP-SS configuration information includes event configuration information; receiving a radio resource control (RRC) release message from the base station; entering an RRC idle state or an RRC inactive state on the basis of the RRC release message; measuring an LP-SS received from the base station on the basis of the LP-SS configuration information; logging measurement results for the LP-SS if an event configured on the basis of the event configuration information is satisfied; and transmitting the logged measurement results to the base station if entering an RRC connected state.

Description

Method and device for optimizing LP-WUR / WUS functions in a mobile communication system

[0001] The present disclosure relates to terminal and base station operations in a mobile communication system. Specifically, the present disclosure relates to a method and apparatus for optimizing LP-WUR / WUS functions in a mobile communication system.

[0002] 5G mobile communication technology defines a wide frequency band to enable fast transmission speeds and new services, and can be implemented not only in frequency bands below 6 GHz ('Sub 6 GHz'), such as 3.5 gigahertz (3.5 GHz), but also in ultra-high frequency bands called millimeter waves (mmWave), such as 28 GHz and 39 GHz ('Above 6 GHz'). In addition, for 6G mobile communication technology, which is referred to as a system beyond 5G, implementation in the terahertz band (e.g., the 3 terahertz (3 THz) band at 95 GHz) is being considered to achieve transmission speeds 50 times faster and ultra-low latency reduced to one-tenth compared to 5G mobile communication technology.

[0003] In the early stages of 5G mobile communication technology, aiming to satisfy service support and performance requirements for enhanced Mobile BroadBand (eMBB), Ultra-Reliable Low-Latency Communications (URLLC), and massive Machine-Type Communications (mMTC), technologies such as beamforming and Massive MIMO to mitigate path loss and increase transmission distance in ultra-high frequency bands, support for various numerologies (such as the operation of multiple subcarrier spacings) and dynamic operation of slot formats for the efficient utilization of ultra-high frequency resources, initial access techniques to support multi-beam transmission and broadband, definition and operation of Band-Width Parts (BWP), Low Density Parity Check (LDPC) codes for high-volume data transmission, new channel coding methods such as Polar Codes for the reliable transmission of control information, and L2 pre-processing (L2 Standardization has been carried out for pre-processing, network slicing which provides a dedicated network specialized for specific services, and other methods.

[0004] Currently, discussions are underway to improve and enhance the performance of the initial 5G mobile communication technology, taking into account the services that the 5G mobile communication technology was intended to support. Additionally, standardization of the physical layer is in progress for technologies such as V2X (Vehicle-to-Everything), which helps autonomous vehicles make driving decisions and enhance user convenience based on their own location and status information transmitted by the vehicle; NR-U (New Radio Unlicensed), which aims for system operation in unlicensed bands to comply with various regulatory requirements; NR terminal low power consumption technology (UE Power Saving); Non-Terrestrial Network (NTN), which is direct terminal-satellite communication for securing coverage in areas where communication with the terrestrial network is impossible; and positioning.

[0005] In addition, standardization is underway in the field of wireless interface architecture / protocols for technologies such as the Industrial Internet of Things (IIoT) for supporting new services through linkage and convergence with other industries, Integrated Access and Backhaul (IAB) which provides nodes for expanding network service areas by integrating wireless backhaul links and access links, Mobility Enhancement including Conditional Handover and Dual Active Protocol Stack (DAPS) Handover, and 2-step Random Access (2-step RACH for NR) which simplifies random access procedures. Standardization is also underway in the field of system architecture / services for 5G baseline architectures (e.g., Service based Architecture, Service based Interface) for incorporating Network Functions Virtualization (NFV) and Software-Defined Networking (SDN) technologies, and Mobile Edge Computing (MEC), which provides services based on the location of the terminal.

[0006] When such 5G mobile communication systems are commercialized, connected devices, which are increasing explosively, will be connected to communication networks. Accordingly, it is expected that there will be a need to enhance the functionality and performance of 5G mobile communication systems and to integrate the operation of connected devices. To this end, new research is planned to be conducted on 5G performance improvement and complexity reduction, support for AI services, support for metaverse services, and drone communication using eXtended Reality (XR), Artificial Intelligence (AI), and Machine Learning (ML) to efficiently support Augmented Reality (AR), Virtual Reality (VR), and Mixed Reality (MR).

[0007] Furthermore, the advancement of these 5G mobile communication systems encompasses multi-antenna transmission technologies such as new waveforms to guarantee coverage in the terahertz band of 6G mobile communication technology, Full Dimensional MIMO (FD-MIMO), array antennas, and large-scale antennas; metamaterial-based lenses and antennas to improve terahertz band signal coverage; high-dimensional spatial multiplexing technology using OAM (Orbital Angular Momentum); and Reconfigurable Intelligent Surface (RIS) technology; as well as Full Duplex technology for enhancing frequency efficiency and system networks in 6G mobile communication technology; AI-based communication technologies that realize system optimization by utilizing satellites and AI from the design stage and internalizing end-to-end AI support functions; and the realization of services of complexity exceeding the limits of terminal computing capabilities by utilizing ultra-high-performance communication and computing resources. It could serve as a foundation for the development of next-generation distributed computing technologies.

[0008] Embodiments of the present disclosure provide an apparatus and a method capable of effectively providing services in a mobile communication system. Specifically, embodiments of the present disclosure provide a method for optimizing LP-WUR / WUS.

[0009] The present disclosure, for solving the above-mentioned problems, comprises a method performed by a terminal in a communication system, wherein the method comprises: receiving MDT (minimization of drive test) setting information including LP-SS (low power-synchronization signal) setting information from a base station; wherein the LP-SS setting information includes event setting information; receiving an RRC (radio resource control) release message from the base station; entering an RRC idle state or an RRC inactive state based on the RRC release message; measuring the LP-SS received from the base station based on the LP-SS setting information; logging the measurement result for the LP-SS when the event set based on the event setting information is satisfied; and transmitting the logged measurement result to the base station when entering an RRC connection state.

[0010] In addition, the present disclosure for solving the above-mentioned problems comprises a method performed by a base station in a communication system, the step of transmitting MDT (minimization of drive test) setting information including LP-SS (low power-synchronization signal) setting information to a terminal, wherein the LP-SS setting information includes event setting information; the step of transmitting an RRC (radio resource control) release message to the terminal; and the step of receiving a measurement result for the LP-SS logged to the terminal from the terminal when the terminal enters an RRC connection state, wherein the measurement result for the LP-SS is determined based on the LP-SS setting information, and the measurement result for the LP-SS is logged when the event set based on the event setting information is satisfied.

[0011] In addition, the present disclosure for solving the above-mentioned problems comprises, in a terminal of a communication system, a transceiver; and a control unit connected to the transceiver, wherein the control unit receives MDT (minimization of drive test) setting information including LP-SS (low power-synchronization signal) setting information from a base station, wherein the LP-SS setting information includes event setting information, receives an RRC (radio resource control) release message from the base station, enters an RRC idle state or an RRC inactive state based on the RRC release message, measures the LP-SS received from the base station based on the LP-SS setting information, logs the measurement result for the LP-SS when the event set based on the event setting information is satisfied, and transmits the logged measurement result to the base station when entering an RRC connection state.

[0012] In addition, the present disclosure for solving the above-mentioned problems comprises, in a base station of a communication system, a transceiver; and a control unit connected to the transceiver, wherein the control unit transmits MDT (minimization of drive test) setting information including LP-SS (low power-synchronization signal) setting information to a terminal, wherein the LP-SS setting information includes event setting information, transmits an RRC (radio resource control) release message to the terminal, and when the terminal enters an RRC connection state, receives a measurement result for the LP-SS logged to the terminal from the terminal, wherein the measurement result for the LP-SS is determined based on the LP-SS setting information, and when an event set based on the event setting information is satisfied, the measurement result for the LP-SS is logged.

[0013] Through the embodiments of the present disclosure, services can be effectively provided in a mobile communication system. Through the embodiments of the present disclosure, the LP-WUR / WUS can be optimized to efficiently use the power of the terminal.

[0014] FIG. 1a is a drawing illustrating the structure of a next-generation mobile communication system according to one embodiment of the present disclosure.

[0015] FIG. 1b is a drawing illustrating an LP-WUR / WUS in a next-generation mobile communication system according to one embodiment of the present disclosure.

[0016] FIG. 1c is a diagram illustrating an LP-WUS / LP-SS (low power-synchronization signal) service area according to one embodiment of the present disclosure.

[0017] FIG. 1d is a diagram illustrating a technique for collecting (logging) and reporting cell measurement information according to one embodiment of the present invention.

[0018] FIG. 1e is a drawing illustrating a method for collecting and reporting cell measurement information according to one embodiment of the present disclosure.

[0019] FIG. 1f is a flowchart of an operation for collecting and reporting cell measurement information according to one embodiment of the present disclosure.

[0020] FIG. 1g is a flowchart of an operation for collecting and reporting LP-SS related information according to one embodiment of the present disclosure.

[0021] FIG. 1h is a flowchart of a terminal operation for collecting and reporting LP-SS related information according to one embodiment of the present disclosure.

[0022] FIG. 1i is a flowchart of a base station operation for collecting and reporting LP-SS related information according to one embodiment of the present disclosure.

[0023] FIG. 1j is a flowchart of an operation to collect and report LP-SS related information through an early measurement reporting operation in an RRC_INACTIVE state according to one embodiment of the present disclosure.

[0024] FIG. 1k is a flowchart of an operation to collect and report LP-SS related information through an early measurement reporting operation in an RRC_IDLE state according to one embodiment of the present disclosure.

[0025] FIG. 11 is a flowchart of a terminal operation that collects and reports LP-SS related information through an early measurement reporting operation in an RRC_INACTIVE state according to one embodiment of the present disclosure.

[0026] FIG. 1m is a flowchart of a base station operation that collects and reports LP-SS related information through an early measurement reporting operation in an RRC_INACTIVE state according to one embodiment of the present disclosure.

[0027] FIG. 1n is a block diagram illustrating the internal structure of a terminal according to one embodiment of the present disclosure.

[0028] FIG. 10 is a block diagram showing the configuration of a base station according to one embodiment of the present disclosure.

[0029] In the following description of the present invention, specific descriptions of related known functions or configurations will be omitted if it is determined that such detailed descriptions may unnecessarily obscure the essence of the invention. Embodiments of the present invention will be described below with reference to the attached drawings.

[0030] Figure 1a is a diagram illustrating the structure of a next-generation mobile communication system.

[0031] Referring to FIG. 1a, as illustrated, the wireless access network of the next-generation mobile communication system (New Radio, NR) consists of a next-generation base station (New Radio Node B, hereinafter gNB) (1a-10) and an AMF (1a-05, New Radio Core Network). A user terminal (New Radio User Equipment, hereinafter NR UE or terminal) (1a-15) connects to an external network through the gNB (1a-10) and the AMF (1a-05).

[0032] In FIG. 1a, the gNB corresponds to the eNB (Evolved Node B) of the existing LTE system. The gNB is connected to the NR UE via a wireless channel and can provide superior service compared to the existing Node B (1a-20). In next-generation mobile communication systems, since all user traffic is serviced through a shared channel, a device is required to perform scheduling by collecting state information such as the buffer status, available transmission power status, and channel status of the UEs, and this is handled by the gNB (1a-10). A single gNB typically controls multiple cells. To achieve ultra-high-speed data transmission compared to existing LTE, it can have a maximum bandwidth greater than that of existing LTE, and beamforming technology can be additionally incorporated by using Orthogonal Frequency Division Multiplexing (hereinafter referred to as OFDM) as the wireless access technology. Additionally, an Adaptive Modulation & Coding (hereinafter referred to as AMC) method is applied to determine the modulation scheme and channel coding rate according to the terminal's channel status. The AMF (1a-05) performs functions such as mobility support, bearer configuration, and QoS configuration. The AMF is a device responsible for various control functions as well as mobility management functions for the terminal, and is connected to multiple base stations. In addition, the next-generation mobile communication system can be interconnected with the existing LTE system, and the AMF is connected to the MME (1a-25) via a network interface. The MME is connected to the existing base station, eNB (1a-30). A terminal supporting LTE-NR Dual Connectivity can transmit and receive data while maintaining a connection to both the gNB and the eNB (1a-35).

[0033] FIG. 1b is a drawing illustrating an LP-WUR / WUS in a next-generation mobile communication system according to one embodiment of the present disclosure.

[0034] A terminal (1b-05) can perform operations such as data transmission and reception, as well as paging monitoring, cell measurement, and PDCCH monitoring, using its RF (Radio Frequency) transceiver. When using the RF transceiver, the terminal consumes its own power. In this disclosure, the terminal RF transceiver is referred to as MR (Main Radio, 1b-10). Even if data transmission and reception operations are not performed, using the RF transceiver to perform the aforementioned operations consumes relatively large terminal power. A low-power transceiver that consumes less power than the MR may be utilized to perform terminal operations. In this disclosure, this is referred to as LR (Low-Power Wake-up Radio, LP-WUR, 1b-15). Through the LR, the terminal can transmit and receive signals in a frequency bandwidth that is relatively narrow compared to the frequency bandwidth used in the MR. Since the LR handles a relatively narrow frequency band, it has the advantage of consuming less power than the MR.

[0035] The base station (1b-20) may allocate a frequency narrowband for the LR (1b-30) and configure it for the terminal. The base station may transmit an LP-WUS (Low Power Wake-Up Signal, 1b-35) through the narrowband frequency. The LP-WUS control signaling may be transmitted to terminals in a standby or inactive state as a substitute for PEI (Paging Early Indication), or may be used to indicate whether to transmit PEI or paging prior to the transmission of PEI. Terminals receiving the LP-WUS transmitted from the LR decide whether to perform paging monitoring or PEI monitoring in the MR. Meanwhile, the LP-WUS control signaling may be transmitted to terminals in a connected state as a substitute for DCP (DCI with CRC scrambled by PS-RNTI). Terminals that receive the LP-WUS transmitted from the above LR determine whether to perform PDCCH monitoring using MR during the approaching on-Duration time interval. At this time, since the terminal can operate only the LR and then additionally operate MR when necessary, the power consumption of the terminal can be minimized.

[0036] The terminal can transmit an uplink LP-WUS to the base station via LR. The base station may turn off its MR transceiver (1b-25) to save its power consumption. At this time, if necessary, the terminal can transmit an LP-WUS to the base station via the uplink of LR, and the base station that receives this can turn on its MR transceiver.

[0037] FIG. 1c is a drawing illustrating an LP-WUS / LP-SS service area according to one embodiment of the present disclosure.

[0038] The base station (1c-05) can transmit a separate LP-SS (Low Power Synchronization Signal), which is a type of reference signal, so that the terminal (1c-10) can recognize the service area of ​​the LP-WUS. Based on the received signal strength of the LP-SS, the terminal can evaluate (or determine) whether it is located within the service area where the LP-WUS can be received. The LP-SS can be classified as OOK (On-off keying) based or OFDM based, and generally, the service area (1c-20) of the OOK-based LP-SS is narrower than the service area (1c-15) of the OFDM-based LP-SS or the SSB in MR. Even if they are both OFDM-based, the service area of ​​the LP-SS or the SSB in MR may differ.

[0039] The base station may set a threshold value for LP-SS for the terminal. The threshold value may include, for example, a threshold value for RSRP or a threshold value for RSRQ, and below, the RSRP threshold value is used as an example. If the RSRP value of the LP-SS received by the terminal via LR is greater than (or greater than or equal to) the RSRP threshold value, the terminal may be considered (or determined) to be located within a service area capable of receiving LP-WUS (hereinafter referred to as LP-WUS coverage). This is referred to as the entry condition of LP-WUS coverage. The LP-WUS coverage may refer to an area where the terminal can monitor LP-WUS. If the entry condition is satisfied, the terminal may be considered (or determined) to be located within LP-WUS coverage and may monitor whether LP-WUS is being transmitted via LR. The threshold value is intended to determine whether the terminal is located within LP-WUS coverage and may be included in LP-WUS related configuration information.

[0040] On the other hand, the base station may set an RSRP threshold value of the LP-SS for the terminal, and if the RSRP value of the LP-SS received by the terminal via LR is less than (or less than or equal to) the said RSRP threshold value, the terminal may be considered (or determined) to be located outside the LP-WUS coverage. This is referred to as the leaving (exit, stop) condition of the LP-WUS coverage. The said threshold value is intended to determine whether it is located within the LP-WUS coverage and may be included in the LP-WUS related configuration information.

[0041] If the measured value of LP-SS received by the terminal is greater than (or greater than or equal to) a threshold value (e.g., RSRP threshold or RSRQ threshold), the terminal may be considered (or determined) to be within LP-SS coverage. The LP-SS coverage may refer to an area where the terminal can receive LP-SS signals. The LP-SS coverage may be used to verify the signal strength of the network for SON / MDT (Minimization of Drive Test). The threshold value is used to determine whether it is located within LP-SS coverage and may be included in LP-SS related configuration information. The LP-SS coverage and LP-WUS coverage may be the same or different depending on the applied threshold value.

[0042] On the other hand, the measurement information of the above LP-SS can also be used to supplement the measurement information in MR.

[0043] FIG. 1d is a drawing illustrating a technique for collecting and reporting cell measurement information in the present disclosure.

[0044] During network construction or optimization, mobile operators typically measure signal strength within the expected service area and, based on this, deploy or realign base stations within that area. Operators load signal measurement equipment onto vehicles to collect cell measurement data within the service area, a process that requires significant time and cost. This process, which generally utilizes vehicles, is commonly referred to as a "Drive Test." Terminals are equipped with the capability to measure signals from base stations to support operations such as cell reselection, handover, or adding a serving cell when moving between cells. Therefore, instead of the aforementioned Drive Test, terminals within the service area can be utilized, a method referred to as MDT. Operators can configure MDT operations for specific terminals through various network components, and these terminals measure and store signal strength from serving cells and surrounding cells while in a connected state (RRC_Connected), standby state (RRC_Idle), or inactive state (RRC_Inactive). In addition, the terminals also store various other information, such as location data, time data, and signal quality data. The stored information can be reported to the network when the terminals are connected, and the information is transmitted to a specific server.

[0045] The above MDT operations are broadly classified into Immediate MDT and Logged MDT.

[0046] Immediate MDT is characterized by immediately reporting information collected by a terminal to the network. Since the information measured by the terminal is reported immediately, only connected terminals can perform Immediate MDT. Typically, it utilizes an RRM measurement process to support operations such as handover and adding serving cells, and additional information such as location and time data may be reported.

[0047] Logged MDT is characterized by storing information collected by a terminal without immediately reporting it to the network, and then reporting the stored information after the terminal transitions to a connected state. Typically, a terminal in a standby state, unable to report measured information to the network, performs Logged MDT. In next-generation mobile communication systems, a terminal in an inactive state performs Logged MDT. When a specific terminal is in a connected state, the network provides the terminal with configuration information for performing Logged MDT operations, and the terminal collects (or measures) and stores the configured information after transitioning to a standby or inactive state.

[0048]

[0049] FIG. 1e is a diagram illustrating a method for collecting and reporting cell measurement information in the present disclosure.

[0050] The terminal (1e-05) transitions from a standby or inactive state (1e-10) to a connected state (1e-15). In the connected state, the terminal collects MDT data through an Immediate MDT operation and reports it to the base station. Meanwhile, the Immediate MDT operation may be performed selectively depending on the terminal's settings. Additionally, in this disclosure, information that the terminal measures, collects, and stores through an MDT operation is referred to as MDT data. However, the MDT data may be referred to by various terms such as MDT information, logged information, etc.

[0051] A terminal that has switched to a connected state receives Logged MDT configuration information from a base station that performs the operation in a standby state or inactive state (1e-20). The configuration information is stored in an RRC message and transmitted to the terminal, and upon receiving the message, the terminal starts a first timer (1e-55). The terminal performs the Logged MDT operation in the standby state or inactive state period until the first timer expires.

[0052] The value of the first timer is included in the Logged MDT configuration information. When the terminal switches to a standby state or an inactive state, Logged MDT is performed according to the Logged MDT configuration information (1e-25).

[0053] The terminal can store information measured or collected at a set period, logging interval (1e-35) (1e-30, 1e-45). Additionally, if valid location information (1e-40) is collected, the terminal can also store the location information. The validity of the location information is determined if a predetermined time (1e-50) has not elapsed after the information is collected. The predetermined time is shorter than or equal to the logged interval. Even before the first timer expires, the terminal can temporarily suspend the Logged MDT operation being performed when transitioning to a connected state (1e-60). However, the first timer does not stop and continues to operate even during the connected state period. That is, the first timer continues to operate regardless of changes in the RRC state. However, the first timer stops when the terminal memory storing MDT data is insufficient to store more MDT data, or when the Logged MDT setting information is released. The above Logged MDT configuration information is released when other Logged MDT configuration information is provided by a serving RAT or another RAT, or when the terminal is detached or its power is cut off. During the connection establishment (RRC Connection Establishment) or connection restart (RRC Connection Resume) process, the terminal reports to the base station that it is storing measurement information or collected information (MDT data) using an RRC Setup Complete message or an RRC Resume Complete message (1e-65).

[0054] The above connection establishment process is the process in which a terminal transitions from a standby state to a connected state. The connection establishment process typically consists of three stages as follows, and three types of RRC messages may be used.

[0055] - Step 1: The terminal sends an RRC Setup Request message to the base station

[0056] - Step 2: Base station sends RRC Setup message to terminal

[0057] - Step 3: The terminal sends an RRC Setup Complete message to the base station

[0058] The above connection restart process is a process in which a terminal transitions from an inactive state to a connected state. The connection restart process typically consists of three steps as follows, and three types of RRC messages are used.

[0059] - Step 1: The terminal sends an RRC Resume Request message to the base station

[0060] - Step 2: Base station sends RRC Resume message to terminal

[0061] - Step 3: The terminal sends an RRC Resume Complete message to the base station

[0062] The terminal may report information indicating that it possesses the above-mentioned collected information to the target base station during the Connection Reestablishment (RRC) and Handover processes, in addition to the connection establishment or connection restart processes. If the above-mentioned Logged MDT is configured but there is no information collected and stored yet, the above-mentioned report may be omitted.

[0063] Upon receiving the above report, the base station may request the reporting of MDT data stored by the terminal if necessary. The terminal must store the unreported MDT data for a specified period of time. When the terminal is switched back to a standby or inactive state and the first timer has not yet expired, the Logged MDT operation is restarted (1e-70).

[0064] If the first timer expires, the Logged MDT operation is stopped (1e-75). The terminal that stopped the operation starts a second timer (1e-80) and retains the stored MDT data until the timer expires. After the timer expires, the terminal implementation determines whether to delete the stored MDT data. The value of the second timer may be included in the Logged MDT setting information, or a predefined value may be applied without being set.

[0065] When the terminal is switched back to a connected state, the terminal reports to the base station that it is storing collected information (MDT data) (1e-85). The base station requests the terminal to report the MDT data it is storing using a predetermined RRC message (1e-90). Accordingly, the terminal receives the MDT data it is storing in the predetermined RRC message and reports the message to the base station (1e-95).

[0066] FIG. 1f is a flowchart of the operation of collecting and reporting cell measurement information in the present disclosure.

[0067] The terminal (1f-05) establishes a connection with the base station (1f-10) (1f-15). The terminal provides terminal capability information to the base station (1f-20), and through the terminal capability information, the base station may indicate whether the terminal supports MDT operation and whether it can measure any frequency. Meanwhile, the step of providing terminal capability information after the terminal has established an RRC connection with the base station is not necessarily required. The base station may use terminal capability information previously received and stored from the terminal. Alternatively, the terminal may transmit the terminal capability information to the base station upon the request of the base station, and the terminal may provide the terminal capability information upon the request of the base station at a step other than step 1f-20.

[0068] The base station transmits the configuration information required to perform a Logged MDT operation to the terminal by storing it in an RRC message (1f-25). For example, the configuration information includes at least one of the following information.

[0069] - Trace Reference Information

[0070] - Trace Recording Session Reference Information

[0071] - TCE (Trace Collection Entity) ID Information: The base station transmits the MDT data information received from the terminal to the data server designated by the above TCE ID.

[0072] - Absolute Time Information (Absolute Time): The absolute time in the current cell providing Logged MDT configuration information.

[0073] - Area Configuration: This is area information that allows measurement information to be collected and stored through Logged MDT operations, and it is specified on a cell-by-cell basis. Additionally, the Area Configuration may include RAT information from which measurement information must be collected. The list included in the RAT information is either a Black List or a White List. If the list included in the RAT information is a Black List, the terminal collects cell measurement information for RATs not included in the list. If the list included in the RAT information is a White List, the terminal does not collect cell measurement information for RATs not included in the list.

[0074] - Logging Duration: As the value of the first timer above, when the timer is running, the terminal performs a Logged MDT operation in a standby state or in an inactive state.

[0075] - Logging Interval: This is the period for storing collected information.

[0076] - lmn-IdentityList (i.e., MDT PLMN list): PLMN list information that includes PLMN information capable of not only performing the above Logged MDT operation but also reporting whether MDT data is stored and reporting MDT data.

[0077] - An indicator indicating whether to perform a Logged MDT operation in a standby state, an inactive state, or both. The indicator may also be used to indicate an RRC state in which a Logged MDT operation is performed. Therefore, the terminal may perform a Logged MDT operation only in the RRC state indicated by the indicator. Alternatively, without the indicator, it may be defined that the terminal always performs a Logged MDT operation in both the standby and inactive states.

[0078] - An indicator that indicates whether to collect and store beam level measurement information. In next-generation mobile communication systems, beam antennas may be applied. Accordingly, the terminal may store beam level measurement information based on the above indicator. Alternatively, without the above indicator, it may be defined that the terminal always collects and stores beam level measurement information for frequencies performing beam-based operations.

[0079] - Information on the maximum number of beams to be collected or stored, and information on the minimum signal strength of the beams to be stored. The terminal omits the storage of information on beams weaker than the minimum signal strength. If all beams are weaker than the set minimum signal value, the terminal may store information on one beam with the strongest signal strength among them, or include an indicator that all beams are weaker than the set minimum signal value.

[0080] - Type information of MDT settings (Periodical logging or event-triggered logging). The above information includes indicators and related information that specify whether to always collect and record information periodically in a standby or inactive state, or to collect and record information once or periodically only when a preset event is satisfied. The above related information refers to logging interval information applied in periodic logging or event-triggered logging, information indicating the event, etc. The above event may include out-of-coverage or event L1. The above out-of-coverage refers to when the terminal is in any cell selection state, and the above event L1 refers to the case where the received signal strength of the serving cell is lower than the preset threshold value of the received signal strength.

[0081] The terminal that receives the above Logged MDT setting information starts a first timer (e.g., T330) (1f-30). The value of the first timer can be set to be the same as the value of the Logging Duration.

[0082] The base station uses an RRC Release message to switch the terminal to a standby state or an inactive state (1f-35). Depending on which RRC state the terminal is switched to, the RRC Release message contains configuration information for operation in the RRC state.

[0083] If the first timer is running, the terminal performs Logged MDT in a standby or inactive state (1f-40). The terminal measures the signal strength of the serving cell and surrounding cells and obtains location information. When beam level measurement is enabled, the terminal collects and stores signal strength values ​​for beams greater than the set minimum value in the serving cell and adjacent cells. The maximum number of beams that the terminal can store is also set or predefined. The signal strength refers to RSRP, RSRQ, or SINR. The terminal stores the collected information at the Logged Interval period.

[0084] When the first timer expires (1f-45), the terminal stops the Logged MDT operation (1f-50).

[0085] If the terminal is in a standby or inactive state due to the RRC Release message and receives RAN or CN paging from the base station or MO data transmission is enabled, the terminal initializes the establishment process or Resume process for transitioning from the standby or inactive state to the connected state.

[0086] The above establishment or resume process may consist of the following steps.

[0087] - Step 1: The terminal sends an RRC Setup Request message or an RRC Resume Request message to the base station (1f-55)

[0088] - Step 2: The base station sends an RRC Setup message or an RRC Resume message to the terminal (1f-60)

[0089] - Step 3: The terminal sends an RRC Setup Complete message or an RRC Resume Complete message to the base station (1f-65)

[0090] The terminal contains an indicator in the RRC Setup Complete or RRC Resume Complete message indicating whether there is MDT data stored in the terminal. Upon receiving the RRC Setup Complete message, the base station requests the reporting of the MDT data using a predetermined RRC message, UEInformationRequest, if necessary (1f-70). Upon receiving the request, the terminal reports the MDT data using a predetermined RRC message, UEInformationResponse (1f-75).

[0091] FIG. 1g is a flowchart of an operation for collecting and reporting LP-SS related information according to one embodiment of the present disclosure.

[0092] The present disclosure proposes a method in which a terminal collects certain information and reports it to a network so that the network can optimize the service area of ​​LP-WUS / LP-SS. Meanwhile, the process of collecting information in the present disclosure may include a process in which the terminal receives a certain signal, measures it, and verifies the measurement result. Alternatively, the process of collecting information in the present disclosure may include a process in which the terminal receives a certain signal, measures it, and records (logs) the measurement result.

[0093] The terminal (1g-05) establishes an RRC connection with the base station (1g-10) (1g-15). The terminal transmits terminal capability information to the base station (1g-20). The capability information may include an indicator indicating whether the terminal supports a Logged MDT function, and an indicator indicating whether it supports LP-WUR / WUS. Step 1g-05 may be performed based on a request from the base station for a report of terminal capability information. Additionally, step 1g-05 may be omitted.

[0094] The base station sets up a Logged MDT for the terminal using a predetermined RRC message, LoggedMeasurementConfiguration (1g-25). In the present disclosure, the setting information may include setting information for collecting and reporting LP-WUR / WUS related information.

[0095] The base station may set event setting information as follows for the terminal. When the conditions corresponding to the set event are satisfied, the terminal collects information related to LP-WUR / WUS on a one-time or periodic basis. When the conditions are no longer satisfied, the terminal does not collect or record information related to LP-WUR / WUS.

[0096] - Event 1: LP-WUS in-coverage

[0097] In the first event, when the terminal enters LP-WUS coverage (or LP-SS coverage), the terminal performs a Logged MDT operation according to previously received configuration information. The terminal may perform a Logged MDT operation when the entry condition of the LP-WUS coverage previously configured by the base station is satisfied. For example, the entry condition may be defined as when the RSRP value of LP-SS measured by the terminal is greater than (or greater than or equal to) the RSRP threshold of LP-SS previously configured. A separate logging interval value applicable only to the first event may be set by the base station. The terminal may stop the Logged MDT operation in progress when the leaving (or exit, stop) condition of the LP-WUS coverage previously configured by the base station is satisfied. For example, the leaving condition may be defined as when the RSRP value of LP-SS measured by the terminal is smaller than (or less than or equal to) the RSRP threshold of LP-SS previously configured.

[0098] Similarly, an LP-WUS out-of-coverage event may be defined. That is, the terminal can perform a Logged MDT operation when the leaving condition of the LP-WUS coverage previously set by the base station is satisfied.

[0099] - Event 2: Poor LP-SS coverage

[0100] In the second event, when the RSRP value of the LP-SS measured by the terminal is smaller than (or smaller than or equal to) the RSRP threshold of the LP-SS previously set by the base station, the terminal performs a Logged MDT operation according to the previously received configuration information. The network may intend to optimize for areas where the received signal strength of the LP-SS is poor, and the second event may be required for this purpose. On the other hand, for the purpose of identifying good LP-SS coverage, when the RSRP value of the LP-SS measured by the terminal is larger than (or larger than or equal to) the RSRP threshold of the LP-SS previously set by the base station, the terminal may perform a Logged MDT operation according to the previously received configuration information.

[0101] - Third Event: Combination of Serving Cell and LP-SS Conditions

[0102] The third event is a combination of a condition based on the received signal strength of the serving cell on which the terminal is camp-on and a condition based on the received signal strength of the LP-SS of the LR corresponding to the cell. When multiple conditions are satisfied, the terminal can perform a Logged MDT operation according to previously received configuration information. For example, if the RSRP value of the LP-SS measured by the terminal is smaller (or smaller than or equal to) the RSRP threshold value of the LP-SS previously set by the base station, and the RSRP value of the SSB of the serving cell measured by the terminal is larger (or larger than or equal to) the RSRP threshold value of the serving cell previously set by the base station, or if the RSRP value of the LP-SS measured by the terminal is larger (or larger than or equal to) the RSRP threshold value of the LP-SS previously set by the base station, and the RSRP value of the SSB of the serving cell measured by the terminal is smaller (or smaller than or equal to) the RSRP threshold value of the serving cell previously set by the base station, the terminal can perform a Logged MDT operation according to previously received configuration information. Or, if the RSRP value of the LP-SS measured by the terminal is greater than (or greater than or equal to) the RSRP threshold value of the LP-SS previously set by the base station, and the RSRP value of the SSB of the serving cell measured by the terminal is greater than (or greater than or equal to) the RSRP threshold value of the serving cell previously set by the base station, or if the RSRP value of the LP-SS measured by the terminal is smaller than (or less than or equal to) the RSRP threshold value of the LP-SS previously set by the base station, and the RSRP value of the SSB of the serving cell actually measured by the terminal is smaller than (or less than or equal to) the RSRP threshold value of the serving cell previously set by the base station, the terminal may perform a Logged MDT operation according to the previously received configuration information.

[0103] - 4th Event: Combination of LP-SS Conditions

[0104] In the fourth event, when the RSRP value of the LP-SS measured by the terminal is smaller (or smaller than or equal to) the first RSRP threshold of the LP-SS previously set by the base station, and when the RSRP value of the LP-SS measured by the terminal is larger (or larger than or equal to) the first RSRP threshold of the LP-SS previously set by the base station, the terminal performs a Logged MDT operation according to the previously received setting information.

[0105] When the above event is satisfied, the terminal collects and stores specific information one-time or periodically while the conditions of the above event are satisfied. In addition to the above event information, the base station may provide the terminal with configuration information as follows.

[0106] - Indicator information indicating whether to additionally collect and record LP-SS related measurement information when existing periodical logging is configured.

[0107] - LP-SS configuration information. The above LP-SS configuration information may include the center frequency, frequency bandwidth, transmission period of the LP-SS, and type information of the LP-SS (whether it is OOK or OFDM, etc.) of which the LP-SS (which the terminal must collect and record) is transmitted.

[0108] - List information of cells providing LP-SS (for which the terminal must collect and record LP-SS related information). When the terminal is camp-on as a suitable cell in a cell belonging to the list, the terminal can collect and store LP-WUS / LP-SS related information provided by the LR of the cell. The cell list information may be included in the existing Area Configuration setting information. The terminal may also obtain LP-SS setting information from the system information of the cell belonging to the list.

[0109] The terminal that receives the Logged MDT setting information from the base station starts a predetermined timer (1g-30). When the timer expires, the terminal no longer needs to perform the Logged MDT operation even if the predetermined conditions are satisfied.

[0110] The terminal receives an RRCRelease message from the base station (1g-35). Depending on the information contained in the message, the terminal is switched to an RRC_IDLE or RRC_INACTIVE state. The terminal, having switched to an RRC_IDLE or RRC_INACTIVE state, can perform periodic or event-triggered logging operations according to the previously received Logged MDT configuration information (1g-40).

[0111] The terminal can obtain the LP-SS configuration information through system information broadcast from the MR (1g-45). Since the LP-SS transmission pattern (or LP-SS configuration) may change at any time, the LP-SS configuration information obtained through the LoggedMeasurementConfiguration message may no longer be valid after a certain point in time. At this time, the terminal can apply the new LP-SS configuration information included in the system information. The terminal can receive the SSB through the MR and the LP-SS through the LR to derive the signal strengths of the reference signals (1g-50, 1g-55).

[0112] The terminal enters a service area capable of receiving LP-SS (1g-60). When a pre-configured event is satisfied, the terminal can store (log) the following information related to LP-SS / LP-WUS (1g-65). Specific information may be recorded at each logging interval applied while the event is satisfied, and other information may be recorded once after the event is satisfied.

[0113] - LP-SS measurement results

[0114] ■ LP-SS frequency information, carrier frequency, frequency bandwidth, etc.

[0115] ■ RSRP and RSRQ measurement results

[0116] ■ L1-filtered or L3-filtered result

[0117] - LP-WUS coverage entry / exit related information

[0118] ■ Indicators indicating that an LP-WUS coverage entry or exit has occurred

[0119] ◆ The above indicators may be included once in the first log that follows an LP-WUS coverage entry or exit.

[0120] ◆ If both entry and exit occur during the logging interval, the entry and exit indicators, or the indicators of the last occurrence of entry or exit, may be stored in the upcoming log.

[0121] ■ Information on pre-configured LP-WUS coverage entry / exit condition(s)

[0122] ■ Information on satisfied LP-WUS coverage entry / exit condition(s)

[0123] - 'no LP-SS' indicator. Included when the RSRP or RSRQ measurement of LP-SS is less than a predetermined threshold.

[0124] - 'no SSB measurement' indicator. Included when the terminal is not measuring the SSB being broadcast from the MR. Additionally, information on the cause of the terminal not measuring the SSB may be included. For example, the terminal may not measure the SSB by applying a long SSB measurement period for the purpose of measurement offloading or relaxation.

[0125] - 'gNB MR off' indicator. Included when the base station's MR is off and only the base station's LR is operating.

[0126] - An indicator that indicates whether the serving cell supports LR

[0127] - An indicator that indicates whether LR is broadcasting LP-SS

[0128] - Uplink LP-WUS related information

[0129] ■ An indicator that indicates whether the terminal has transmitted an uplink LP-WUS

[0130] ■ An indicator that indicates whether the base station has turned off the MR for the uplink LP-WUS transmitted by the terminal

[0131] - Type information of LP-SS. The type information of the LP-SS may be an indicator indicating whether it is OOK- or OFDM-based.

[0132] If the measured value of the LP-SS is less than (or less than or equal to) a predetermined threshold value, the terminal is not considered to be within LP-SS coverage (1g-70). When the running timer expires (1g-75), the terminal no longer performs the Logged MDT operation (1g-80).

[0133] To transition to a connected state, the terminal initiates an RRC establishment or RRC resume procedure and transmits an RRCSetupRequest or RRCResumeRequest message to the base station (1g-85). The base station transmits an RRCSetup or RRCResume message to the terminal (1g-90). The terminal transmits an RRCSetupComplete or RRCResumeComplete message to the base station containing an indicator that there is certain information collected and stored through its Logged MDT operation (1g-95). Upon receiving the indicator, the base station may request the terminal to report the collected information using a certain RRC message (1g-100). Upon receiving the request, the terminal reports the requested information to the base station using a certain RRC message (1g-105).

[0134] FIG. 1h is a flowchart of a terminal operation for collecting and reporting LP-SS related information according to one embodiment of the present disclosure.

[0135] In step 1h-05, the terminal reports terminal capability information to the base station. The capability information may include an indicator indicating whether the terminal supports the Logged MDT function, and an indicator indicating whether it supports LP-WUR / WUS. Step 1h-05 may be performed based on a request from the base station to report terminal capability information. Additionally, step 1h-05 may be omitted.

[0136] In step 1h-10, the terminal receives a LoggedMeasurementConfiguration message (or RRC message) from the base station that includes Logged MDT configuration information. The configuration information may include configuration information for collecting and reporting LP-WUR / WUS-related information. Additionally, the configuration information may include event configuration information. The terminal can collect information related to LP-WUR / WUS when conditions corresponding to a configured event are satisfied. Specific details regarding the configuration information are the same as those described above and are therefore omitted below. Furthermore, upon receiving the LoggedMeasurementConfiguration message, the terminal activates a predetermined timer.

[0137] In step 1h-15, the terminal receives an RRCRelease message from the base station and switches to a standby state or an inactive state according to the configuration information included in the message.

[0138] In step 1h-20, the terminal detects LP-SS based on LP-SS setting information obtained from RRC messages or system information, and measures it.

[0139] In step 1h-25, when a predetermined condition is satisfied, the terminal records (or stores, logs) measurement information related to LP-SS. Specifically, the information stored by the terminal is the same as described above, so it is omitted below.

[0140] In step 1h-30, the terminal switches to a connected state.

[0141] In step 1h-35, the terminal reports to the base station an indicator indicating that it is storing Logged MDT measurement results using a predetermined RRC message.

[0142] In step 1h-40, the terminal is requested to report the collected information from the base station.

[0143] In step 1h-45, the terminal reports to the base station using a predetermined RRC message containing the requested information.

[0144] FIG. 1i is a flowchart of a base station operation for collecting and reporting LP-SS related information according to one embodiment of the present disclosure.

[0145] In step 1i-05, the base station may receive terminal capability information from the terminal. The capability information may include an indicator indicating whether the terminal supports the Logged MDT function, and an indicator indicating whether the terminal supports LP-WUR / WUS. Step 1i-05 may be performed based on a request from the base station for a report of terminal capability information. Additionally, step 1i-05 may be omitted.

[0146] In step 1i-10, the base station transmits a LoggedMeasurementConfiguration message (or RRC message) containing Logged MDT configuration information to the terminal. The configuration information may include configuration information for collecting and reporting LP-WUR / WUS related information. Additionally, the configuration information may include event configuration information. The terminal can collect information related to LP-WUR / WUS when conditions corresponding to the configured event are satisfied. Specific details regarding the configuration information are the same as those described above and are therefore omitted below.

[0147] In step 1i-15, the base station sends an RRCRelease message to the terminal to switch it to a standby state or an inactive state.

[0148] In step 1i-20, the base station receives a predetermined RRC message from the terminal that includes an indicator indicating that it is storing the Logged MDT measurement results. The terminal can record (or store, log) measurement information related to LP-SS when a preset condition is satisfied.

[0149] In step 1i-25, the base station requests the terminal to report the collected information.

[0150] In step 1i-30, the base station receives a predetermined RRC message containing the requested information from the terminal. The information stored and reported by the terminal is the same as described above, so it is omitted below.

[0151] FIG. 1j is a flowchart of an operation to collect and report LP-SS related information through an early measurement reporting operation in an RRC_INACTIVE state according to one embodiment of the present disclosure.

[0152] The present disclosure is characterized by a terminal supporting an early measurement reporting operation that, after disconnecting the RRC connection with a base station and switching to an inactive state (RRC_INACTIVE), reports the most recently collected LP-SS measurement value to the base station during a resume procedure. Upon receiving the measurement value, the base station can quickly set up an LP-WUS for the terminal.

[0153] The base station can set the measurement setting information (measIdleConfig) that is applied in an RRC disabled state to the terminal through an RRC disconnection message (RRCRelease message) or system information (1j-15).

[0154] Upon receiving the RRCRelease message, the terminal switches to an inactive state (1j-20). The measurement setting information includes setting information related to the LP-SS that the terminal needs to measure. The LP-SS setting information may include the center frequency, frequency bandwidth, transmission period of the LP-SS, and type information of the LP-SS (whether it is OOK or OFDM, etc.) of which the LP-SS (which the terminal needs to collect and record) is transmitted.

[0155] The terminal can measure at least one LP-SS based on the measurement setting information when the RRC is disabled. Additionally, the terminal can record the most recent LP-SS measurement value (1j-25). The measurement value may refer to the RSRP or RSRQ measurement value of the LP-SS. Alternatively, the measurement value may include the collected information disclosed in FIG. 1g.

[0156] The terminal transmits a predetermined RRC message to the base station to switch to a connection state (1j-30). While performing a resume procedure to switch to a connection state, the terminal may transmit to the base station via a predetermined RRC message (1j-45) containing the measurement result in response to a request (1j-35) from the base station.

[0157] The base station that receives the above LP-SS measurement result determines whether to set the LP-WUS for the terminal based on the result. The base station sets the LP-WUS for the terminal using a predetermined RRC message (1j-50). The terminal that receives the setting information monitors whether the LP-WUS is received via LR (1j-55). If the terminal receives the LP-WUS related to itself, it performs a PDCCH monitoring operation in the MR for a predetermined time interval (e.g., the on-duration time interval of the DRX).

[0158] FIG. 1k is a flowchart of an operation to collect and report LP-SS related information through an early measurement reporting operation in an RRC_IDLE state according to one embodiment of the present disclosure.

[0159] The present disclosure is characterized by a terminal supporting an early measurement reporting operation that, after disconnecting the RRC connection with the base station and transitioning to a standby state (RRC_IDLE), reports the most recently collected LP-SS measurement value to the base station during the establishment procedure. Upon receiving the measurement value, the base station can quickly establish an LP-WUS to the terminal.

[0160] The base station can set the measurement setting information (measIdleConfig) that is applied in the RRC standby state to the terminal through an RRC disconnection message (RRCRelease message) or system information (1k-15).

[0161] Upon receiving the RRCRelease message, the terminal switches to a standby state (1k-20). The measurement setting information includes setting information related to the LP-SS that the terminal is to measure. The LP-SS setting information may include the center frequency, frequency bandwidth, transmission period of the LP-SS, and type information of the LP-SS (whether it is OOK or OFDM, etc.) at which the LP-SS (which the terminal is to collect and record) is transmitted.

[0162] The terminal can measure at least one LP-SS based on the measurement setting information when the RRC is disabled. Additionally, the terminal can record the most recent LP-SS measurement value (1k-25). The measurement value may refer to the RSRP or RSRQ measurement value of the LP-SS. Alternatively, the measurement value may include the collected information disclosed in FIG. 1g.

[0163] The terminal transmits a predetermined RRC message to the base station to transition to a connection state (1k-30). In response to the message, the base station transmits a predetermined RRC message (1k-35), and the terminal, having successfully received the message, is considered to have transitioned to a connection state (1k-40). While performing the establishment procedure to transition to a connection state, the terminal transmits a predetermined RRC message to the base station containing an indicator that it is storing predetermined LP-SS related measurement information through an early measurement operation (1k-45). Upon receiving the indicator, the base station requests the LP-SS related information stored by the terminal via a predetermined RRC message (1k-50). In response to the request of the base station, the terminal may be transmitted to the base station via a predetermined RRC message containing the measurement results (1k-55).

[0164] The base station that receives the above LP-SS measurement result determines whether to set the LP-WUS for the terminal based on the result. The base station sets the LP-WUS for the terminal using a predetermined RRC message (1k-60). The terminal that receives the setting information monitors whether the LP-WUS is received via LR (1k-65). If the terminal receives the LP-WUS related to itself, it performs a PDCCH monitoring operation in the MR for a predetermined time interval (e.g., the on-duration time interval of the DRX).

[0165] The above embodiment is applicable not only to the standby state but also to scenarios where the terminal transitions from an inactive state to a connected state.

[0166] FIG. 11 is a flowchart of a terminal operation that collects and reports LP-SS related information through an early measurement reporting operation in an RRC_INACTIVE state according to one embodiment of the present disclosure.

[0167] In step 1l-05, the terminal reports terminal capability information to the base station. The terminal capability information includes an indicator that indicates whether it can measure and report LP-SS while supporting early measurement reporting. Step 1l-05 may be performed based on a request from the base station for reporting terminal capability information. Additionally, step 1l-05 may be omitted.

[0168] In step 1l-10, the terminal receives an RRC Release message from the base station containing configuration information for early measurement reporting. The configuration information for early measurement reporting may also be provided through system information. Hereinafter, the configuration information for early measurement reporting may be referred to as measurement configuration information. The measurement configuration information may include configuration information related to LP-SS. Specifically, the measurement configuration information may include the center frequency at which LP-SS is transmitted, the frequency bandwidth, the transmission period of LP-SS, and type information of LP-SS (such as whether it is OOK or OFDM).

[0169] In step 1l-15, the terminal switches to an inactive state after receiving the message.

[0170] In step 1l-20, the terminal can measure LP-SS based on the received measurement setting information. The terminal stores the measurement result of the most recently measured LP-SS. The terminal does not need to store previous measurement results.

[0171] In step 11-25, the terminal receives an RRCResume message from the base station that includes an indicator requesting an early measurement reporting result.

[0172] In step 1l-30, the terminal reports a predetermined measurement result, including the requested LP-SS measurement result, to the base station via RRCResumeComplete.

[0173] In step 1l-35, the terminal receives LP-WUS configuration information from the base station and performs the configured LP-WUS monitoring operation.

[0174] FIG. 1m is a flowchart of a base station operation that collects and reports LP-SS related information through an early measurement reporting operation in an RRC_INACTIVE state according to one embodiment of the present disclosure.

[0175] In step 1m-05, the base station receives terminal capability information from the terminal. The terminal capability information includes an indicator that indicates whether it is possible to measure and report LP-SS while supporting early measurement reporting. Step 1m-05 may be performed based on the base station's request for reporting of terminal capability information. Additionally, step 1m-05 may be omitted.

[0176] In step 1m-10, the base station transmits an RRC Release message to the terminal containing configuration information for early measurement reporting. Hereinafter, the configuration information for early measurement reporting may be referred to as measurement configuration information. The measurement configuration information may include configuration information related to LP-SS. Specifically, the measurement configuration information may include the center frequency at which LP-SS is transmitted, the frequency bandwidth, the transmission period of LP-SS, and type information of LP-SS (such as whether it is OOK or OFDM).

[0177] In step 1m-15, the base station receives an RRCResumeRequest message from the terminal.

[0178] In step 1m-20, the base station transmits an RRCResume message to the terminal that includes an indicator requesting early measurement reporting results.

[0179] In step 1m-25, the base station receives a report of a predetermined measurement result, including the requested LP-SS measurement result, from the terminal via RRCResumeComplete. The LP-SS measurement result may include the measurement result of the most recently measured LP-SS by the terminal, and may not include previous measurement results.

[0180] In step 1m-30, the base station transmits LP-WUS configuration information to the terminal based on the measurement result.

[0181] FIG. 1n is a block diagram illustrating the internal structure of a terminal to which the present disclosure is applied.

[0182] Referring to the drawing above, the terminal includes an RF (Radio Frequency) processing unit (1n-10), a baseband processing unit (1n-20), a storage unit (1n-30), and a control unit (1n-40).

[0183] The RF processing unit (1n-10) performs functions for transmitting and receiving signals through a wireless channel, such as signal band conversion and amplification. That is, the RF processing unit (1n-10) up-converts the baseband signal provided by the baseband processing unit (1n-20) into an RF band signal and transmits it through an antenna, and down-converts the RF band signal received through the antenna into a baseband signal. For example, the RF processing unit (1n-10) may include a transmission filter, a reception filter, an amplifier, a mixer, an oscillator, a DAC (digital to analog converter), an ADC (analog to digital converter), etc. Although only one antenna is shown in the drawing, the terminal may be equipped with multiple antennas. In addition, the RF processing unit (1n-10) may include multiple RF chains. Furthermore, the RF processing unit (1n-10) may perform beamforming. For the above beamforming, the RF processing unit (1n-10) can adjust the phase and magnitude of each of the signals transmitted and received through a plurality of antennas or antenna elements. In addition, the RF processing unit can perform MIMO and can receive multiple layers when performing MIMO operation.

[0184] The baseband processing unit (1n-20) performs a conversion function between a baseband signal and a bit sequence according to the physical layer specifications of the system. For example, when transmitting data, the baseband processing unit (1n-20) generates complex symbols by encoding and modulating the transmitted bit sequence. Additionally, when receiving data, the baseband processing unit (1n-20) restores the received bit sequence by demodulating and decoding the baseband signal provided by the RF processing unit (1n-10). For example, in the case of following the orthogonal frequency division multiplexing (OFDM) method, when transmitting data, the baseband processing unit (1n-20) generates complex symbols by encoding and modulating the transmitted bit sequence, maps the complex symbols to subcarriers, and then constructs OFDM symbols through inverse fast Fourier transform (IFFT) operations and cyclic prefix (CP) insertion. Additionally, upon receiving data, the baseband processing unit (1n-20) divides the baseband signal provided by the RF processing unit (1n-10) into OFDM symbol units, restores the signals mapped to subcarriers through a fast Fourier transform (FFT) operation, and then restores the received bit sequence through demodulation and decoding.

[0185] The baseband processing unit (1n-20) and the RF processing unit (1n-10) transmit and receive signals as described above. Accordingly, the baseband processing unit (1n-20) and the RF processing unit (1n-10) may be referred to as a transmitting unit, a receiving unit, a transmitting and receiving unit, or a communication unit. Furthermore, at least one of the baseband processing unit (1n-20) and the RF processing unit (1n-10) may include a plurality of communication modules to support a plurality of different wireless access technologies. Additionally, at least one of the baseband processing unit (1n-20) and the RF processing unit (1n-10) may include different communication modules to process signals of different frequency bands. For example, the different wireless access technologies may include wireless LAN (e.g., IEEE 802.11), cellular network (e.g., LTE), etc. In addition, the above different frequency bands may include super high frequency (SHF) bands (e.g., 2 NRHz, NRHz) and millimeter wave (e.g., 60 GHz) bands.

[0186] The storage unit (1n-30) stores data such as basic programs, application programs, and configuration information for the operation of the terminal. In particular, the storage unit (1n-30) can store information related to a second connection node that performs wireless communication using a second wireless connection technology. Additionally, the storage unit (1n-30) provides the stored data upon the request of the control unit (1n-40).

[0187] The control unit (1n-40) controls the overall operations of the terminal. For example, the control unit (1n-40) transmits and receives signals through the baseband processing unit (1n-20) and the RF processing unit (1n-10). Additionally, the control unit (1n-40) writes and reads data to and from the storage unit (1n-40). To this end, the control unit (1n-40) may include at least one processor. For example, the control unit (1n-40) may include a communication processor (CP) that performs control for communication and an application processor (AP) that controls upper layers such as applications.

[0188] FIG. 10 is a block diagram showing the configuration of a base station according to the present disclosure.

[0189] As illustrated in the drawing above, the base station is configured to include an RF processing unit (10-10), a baseband processing unit (10-20), a backhaul communication unit (10-30), a storage unit (10-40), and a control unit (10-50).

[0190] The RF processing unit (10-10) performs functions for transmitting and receiving signals through a wireless channel, such as signal band conversion and amplification. That is, the RF processing unit (10-10) upconverts the baseband signal provided by the baseband processing unit (10-20) into an RF band signal, transmits it through an antenna, and downconverts the RF band signal received through the antenna into a baseband signal. For example, the RF processing unit (10-10) may include a transmit filter, a receive filter, an amplifier, a mixer, an oscillator, a DAC, an ADC, etc. Although only one antenna is shown in the drawing, the first connection node may be equipped with multiple antennas. Additionally, the RF processing unit (10-10) may include multiple RF chains. Furthermore, the RF processing unit (10-10) may perform beamforming. For the above beamforming, the RF processing unit (10-10) can adjust the phase and magnitude of each of the signals transmitted and received through a plurality of antennas or antenna elements. The RF processing unit can perform down-to-down MIMO operation by transmitting one or more layers.

[0191] The baseband processing unit (10-20) performs a conversion function between a baseband signal and a bit sequence according to the physical layer specifications of the first wireless access technology. For example, when transmitting data, the baseband processing unit (10-20) generates complex symbols by encoding and modulating the transmitted bit sequence. Additionally, when receiving data, the baseband processing unit (10-20) restores the received bit sequence by demodulating and decoding the baseband signal provided by the RF processing unit (10-10). For example, in the case of following the OFDM method, when transmitting data, the baseband processing unit (10-20) generates complex symbols by encoding and modulating the transmitted bit sequence, maps the complex symbols to subcarriers, and then constructs OFDM symbols through IFFT operation and CP insertion. Additionally, upon receiving data, the baseband processing unit (10-20) divides the baseband signal provided by the RF processing unit (10-10) into OFDM symbol units, restores the signals mapped to subcarriers through FFT operations, and then restores the received bit sequence through demodulation and decoding. The baseband processing unit (10-20) and the RF processing unit (10-10) transmit and receive signals as described above. Accordingly, the baseband processing unit (10-20) and the RF processing unit (10-10) may be referred to as a transmitting unit, a receiving unit, a transmitting and receiving unit, a communication unit, or a wireless communication unit.

[0192] The backhaul communication unit (1o-30) provides an interface for communicating with other nodes within the network. That is, the backhaul communication unit (1o-30) converts a bit sequence transmitted from the main base station to another node, e.g., an auxiliary base station, a core network, etc., into a physical signal, and converts a physical signal received from the other node into a bit sequence.

[0193] The storage unit (1o-40) stores data such as basic programs, application programs, and configuration information for the operation of the main station. In particular, the storage unit (1o-40) can store information regarding a bearer assigned to a connected terminal, measurement results reported from the connected terminal, etc. Additionally, the storage unit (1o-40) can store information that serves as a criterion for determining whether to provide or disconnect multiple connections to the terminal. Furthermore, the storage unit (1o-40) provides the stored data upon the request of the control unit (1o-50).

[0194] The control unit (10-50) controls the overall operations of the main station. For example, the control unit (10-50) transmits and receives signals through the baseband processing unit (10-20) and the RF processing unit (10-10) or through the backhaul communication unit (10-30). Additionally, the control unit (10-50) writes and reads data to and from the storage unit (10-40). To this end, the control unit (10-50) may include at least one processor.

Claims

1. A method performed by a terminal in a communication system, A step of receiving MDT (minimization of drive test) setting information including LP-SS (low power-synchronization signal) setting information from a base station, wherein the LP-SS setting information includes event setting information; A step of receiving an RRC (radio resource control) release message from the base station; A step of entering an RRC idle state or an RRC inactive state based on the above RRC release message; A step of measuring the LP-SS received from the base station based on the above LP-SS setting information; A step of logging the measurement result for the LP-SS when the event set based on the above event setting information is satisfied; and A method characterized by including the step of transmitting the logged measurement result to the base station when entering an RRC connection state.

2. In Paragraph 1, The above event is, A method characterized by satisfying the following conditions when the terminal enters LP-SS coverage, when the measured value of the LP-SS is smaller than a threshold value, when a condition based on the measured value of the serving cell and the measured value of the LP-SS is satisfied, or when a condition based on the measured value of the LP-SS is satisfied.

3. In Paragraph 1, A method characterized by including at least one of the above-mentioned logged measurement result, LP-SS frequency information, an LP-SS measurement result including a measurement result value and a filtered result value, information related to LP-SS coverage entry, an indicator indicating that the LP-SS measurement value is smaller than a threshold value, an indicator indicating that the SSB (synchronization signal block) is not measured, an indicator indicating that the base station's MR (main radar) is in an off state, an indicator indicating whether the serving cell supports LR (low power wake-up radio), an indicator indicating whether the LR transmits LP-SS, information related to uplink LP-WUS (low power-wake-up signal), and LP-SS type information.

4. In Paragraph 1, It further includes the step of transmitting terminal capability information to the above base station, A method characterized by further including information indicating whether the above terminal capability information supports LP-WUS.

5. In a method performed by a base station in a communication system, A step of transmitting MDT (minimization of drive test) setting information including LP-SS (low power-synchronization signal) setting information to a terminal, wherein the LP-SS setting information includes event setting information; A step of transmitting an RRC (radio resource control) release message to the above terminal; and When the terminal enters an RRC connection state, the method includes the step of receiving a measurement result for the LP-SS logged to the terminal from the terminal, and The measurement result for the above LP-SS is determined based on the above LP-SS setting information, and A method characterized by logging a measurement result for the LP-SS when an event set based on the above event setting information is satisfied.

6. In Paragraph 5, The above event is, A method characterized by satisfying the following conditions when the terminal enters LP-SS coverage, when the measured value of the LP-SS is smaller than a threshold value, when a condition based on the measured value of the serving cell and the measured value of the LP-SS is satisfied, or when a condition based on the measured value of the LP-SS is satisfied.

7. In Paragraph 5, A method characterized by including at least one of the above-mentioned logged measurement result, LP-SS frequency information, an LP-SS measurement result including a measurement result value and a filtered result value, information related to LP-SS coverage entry, an indicator indicating that the LP-SS measurement value is smaller than a threshold value, an indicator indicating that the SSB (synchronization signal block) is not measured, an indicator indicating that the base station's MR (main radar) is in an off state, an indicator indicating whether the serving cell supports LR (low power wake-up radio), an indicator indicating whether the LR transmits LP-SS, information related to uplink LP-WUS (low power-wake-up signal), and LP-SS type information.

8. In Paragraph 5, The method further includes the step of receiving terminal capability information from the above terminal, A method characterized by further including information indicating whether the above terminal capability information supports LP-WUS.

9. In a terminal in a communication system, Transmitter / receiver; and It includes a control unit connected to the above-mentioned transmitting and receiving unit, and The above control unit is, Receive MDT (minimization of drive test) configuration information including LP-SS (low power-synchronization signal) configuration information from a base station, and the LP-SS configuration information includes event configuration information, Receive an RRC (radio resource control) release message from the above base station, and Based on the above RRC release message, enter the RRC idle state or RRC inactive state, and Based on the above LP-SS setting information, the LP-SS received from the base station is measured, and If the event set based on the above event setting information is satisfied, the measurement result for the above LP-SS is logged, and A terminal characterized by transmitting the logged measurement result to the base station when entering an RRC connection state.

10. In Paragraph 9, The above event is, A terminal characterized by satisfying the following conditions when the terminal enters LP-SS coverage, when the measured value of the LP-SS is smaller than a threshold value, when a condition based on the measured value of the serving cell and the measured value of the LP-SS is satisfied, or when a condition based on the measured value of the LP-SS is satisfied.

11. In Paragraph 9, A terminal characterized by including at least one of the above-mentioned logged measurement result, LP-SS measurement result including LP-SS frequency information, a measurement result value, and a filtered result value, information related to entering LP-SS coverage, an indicator indicating that the LP-SS measurement value is smaller than a threshold value, an indicator indicating that the SSB (synchronization signal block) is not measured, an indicator indicating that the base station's MR (main radar) is in an off state, an indicator indicating whether the serving cell supports LR (low power wake-up radio), an indicator indicating whether the LR transmits LP-SS, information related to uplink LP-WUS (low power-wake-up signal), and LP-SS type information.

12. In Paragraph 9, The above control unit transmits terminal capability information to the base station, and A terminal characterized by the above terminal capability information further including information indicating whether it supports LP-WUS.

13. In a base station of a communication system, Transmitter / receiver; and It includes a control unit connected to the above-mentioned transmitting and receiving unit, and The above control unit is, MDT (minimization of drive test) configuration information including LP-SS (low power-synchronization signal) configuration information is transmitted to a terminal, and the LP-SS configuration information includes event configuration information, Send an RRC (radio resource control) release message to the above terminal, and When the above terminal enters an RRC connection state, it receives measurement results for the LP-SS logged to the terminal from the terminal, and The measurement result for the above LP-SS is determined based on the above LP-SS setting information, and A base station characterized by logging the measurement result for the LP-SS when the event set based on the above event setting information is satisfied.

14. In Paragraph 13, The above event is, A base station characterized by satisfying the following conditions when the terminal enters LP-SS coverage, when the measured value of the LP-SS is smaller than a threshold value, when a condition based on the measured value of the serving cell and the measured value of the LP-SS is satisfied, or when a condition based on the measured value of the LP-SS is satisfied.

15. In Paragraph 13, The method further includes the step of receiving terminal capability information from the above terminal, The above terminal capability information further includes information indicating whether it supports LP-WUS, and A base station characterized by including at least one of the following: the above-mentioned logged measurement result, LP-SS measurement result including LP-SS frequency information, a measurement result value, and a filtered result value; information related to entering LP-SS coverage; an indicator indicating that the LP-SS measurement value is smaller than a threshold value; an indicator indicating that the SSB (synchronization signal block) is not measured; an indicator indicating that the base station's MR (main radar) is in an off state; an indicator indicating whether the serving cell supports LR (low power wake-up radio); an indicator indicating whether the LR transmits LP-SS; information related to uplink LP-WUS (low power-wake-up signal); and LP-SS type information.

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