Method and device for recording information in mobile communication system

Abstract

The present disclosure relates to a method and apparatus for operating a user equipment (UE) in a wireless communication system. The method may include: receiving an RRC message from a base station, the RRC message including logged minimization of drive test (MDT) configuration information, the logged MDT configuration information being used to record the results of measurements when the UE is in an RRC idle mode or an RRC inactive mode; based on the logged MDT configuration information, identifying a report type configured for the UE; based on the report type and the logged MDT configuration information including at least one of a PLMN identification list or area configuration information, determining whether a condition for performing logged MDT is met; when the execution condition is met, performing measurements based on a set logging interval; and storing the results of the measurements.

Description

Technical Field

[0001] The present disclosure relates to a method and apparatus for performing information logging in a mobile communication system. Background Art

[0002] Efforts have been made to develop improved fifth generation (5G) communication systems or pre-5G communication systems to keep up with the growing demand for wireless data traffic after the commercialization of the fourth generation (4G) communication system. For this reason, 5G or pre-5G communication systems are referred to as super 4G network communication systems or post-long term evolution (LTE) systems. It is being considered to implement 5G communication systems in ultra-high frequency (millimeter wave (mmWave)) bands such as the 60 gigahertz (GHz) band to achieve high data transmission rates. In order to reduce the path loss of radio waves and increase the transmission distance of radio waves in the ultra-high frequency band of the 5G communication system, technologies such as beamforming, massive multiple input multiple output (massive MIMO), full-dimensional MIMO (FD-MIMO), array antennas, analog beamforming, and massive antennas are being studied. In addition, in order to improve the system network for 5G communication systems, various technologies are being developed, including evolved small cells, advanced small cells, cloud radio access networks (Cloud-RAN), ultra-dense networks, device-to-device (D2D) communication, wireless backhaul, mobile networks, cooperative communications, coordinated multi-point (CoMP), and reception interference cancellation. In addition, for 5G systems, advanced coding modulation (ACM) schemes (such as hybrid FSK and QAM modulation (FQAM) and sliding window superposition coding (SWSC)) and advanced access technologies (such as filter bank multi-carrier (FBMC), non-orthogonal multiple access (NOMA), sparse code multiple access (SCMA), etc.) are being developed.

[0003] In addition, the Internet has evolved from a human-centered connection network in which humans create and consume information to an Internet of Things (IoT) network in which decentralized components, such as objects, exchange information with each other to process information. Internet of Everything (IoE) technology has emerged, in which IoT technology is combined with technology for processing big data, such as by connecting to a cloud server. In order to realize IoT, technologies such as sensing technology, wired / wireless communication and network infrastructure, service interface technology, and security technology are required, and therefore, technologies such as sensor networks for interconnected objects, machine-to-machine (M2M) communication, and machine-type communication (MTC) have recently been studied. In the IoT environment, smart Internet technology services can be provided to create new value for human life by collecting and analyzing data obtained from interconnected objects. Through the fusion and integration between existing information technology (IT) and various industries, IoT can be applied to various fields such as smart homes, smart buildings, smart cities, smart cars or connected cars, smart grids, healthcare, smart appliances, advanced medical services, etc.

[0004] Therefore, various attempts are being made to apply 5G communication systems to IoT networks. For example, technologies such as sensor networks, M2M communications, MTC, etc. are implemented using 5G communication technologies such as beamforming, MIMO, array antennas, etc. Cloud RAN as an application of the above-mentioned big data processing technology can be an example of the fusion between 5G and IoT technologies.

[0005] Due to the development of mobile communication systems and the aforementioned technologies, various services can be provided, and in particular, a method for performing information recording in a mobile communication system is required. Summary of the invention

[0006] Technical issues

[0007] Embodiments of the present disclosure provide a method and apparatus for performing information recording in a mobile communication system.

[0008] Solution to the problem

[0009] According to an embodiment of the present disclosure, an operation method of a user equipment (UE) in a wireless communication system may include: receiving a radio resource control (RRC) message from a base station, the RRC message including logged minimization of drive tests (MDT) configuration information, the logged MDT configuration information being used to perform logging of measurement results when the UE is in an RRC idle mode or an RRC inactive mode; based on the logged MDT configuration information, identifying a report type configured for the UE; based on the report type and the logged MDT configuration information including at least one of a public land mobile network (PLMN) identity list or area configuration information, determining whether a condition for performing logged MDT is met; when the condition is met, performing measurement based on a configured logging interval; and performing logging of measurement results.

[0010] Advantageous Effects of the Present Disclosure

[0011] According to an embodiment of the present disclosure, a method and apparatus for efficiently performing information recording in a mobile communication system may be provided. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1A The structure of the next generation mobile communication system is shown.

[0013] Figure 1B is a diagram for explaining a radio resource control (RRC) state transition in a next generation mobile communication system.

[0014] Figure 1C is a diagram for explaining a technique for collecting and reporting cell measurement information according to an embodiment of the present disclosure.

[0015] Figure 1D is a diagram illustrating a method of collecting and reporting cell measurement information according to an embodiment of the present disclosure.

[0016] Figure 1E is a flowchart of operations for collecting and reporting cell measurement information according to an embodiment of the present disclosure.

[0017] Figure 1F is a diagram for explaining a radio link monitoring (RLM) operation according to an embodiment of the present disclosure.

[0018] Figure 1G is a diagram for explaining a radio link failure (RLF) operation and an RLF report according to an embodiment of the present disclosure.

[0019] Figure 1H is a diagram for explaining a random access (RA) report according to an embodiment of the present disclosure.

[0020] Fig. 1I is a flowchart of an operation of collecting and reporting cell measurement information by considering a public land mobile network (PLMN) and an area configuration according to an embodiment of the present disclosure.

[0021] Figure 1J is a flowchart of an operation of a terminal storing cell measurement information by considering a registered PLMN (RPLMN) and an area configuration according to an embodiment of the present disclosure.

[0022] Figure 1K is a flowchart of an operation of a terminal reporting location information according to an embodiment of the present disclosure.

[0023] Figure 1L is a block diagram of an internal configuration of a terminal according to an embodiment of the present disclosure.

[0024] Figure 1M is a block diagram of a configuration of a base station according to an embodiment of the present disclosure. DETAILED DESCRIPTION

[0025] According to an embodiment of the present disclosure, an operation method of a user equipment (UE) in a wireless communication system may include: receiving a radio resource control (RRC) message from a base station, the RRC message including logged minimization of drive test (MDT) configuration information, the logged MDT configuration information being used to perform logging of measurement results when the UE is in an RRC idle (RRC IDLE) mode or an RRC inactive (RRC INACTIVE) mode; based on the logged MDT configuration information, identifying a report type configured for the UE; based on the report type and the logged MDT configuration information including at least one of a public land mobile network (PLMN) identity list or area configuration information, determining whether a condition for performing logged MDT is met; when the condition is met, performing measurement based on a configured logging interval; and performing logging of measurement results.

[0026] According to an embodiment of the present disclosure, determining whether a condition for performing logged MDT is met may include: in a case where the report type is identified as event triggered, based on logged MDT configuration information, identifying the event type configured for the UE; and in a case where the event type is identified as event L1, when the UE resides in a cell in a normal resident state, a registered PLMN (RPLMN) is included in a PLMN identification list stored in the UE, and the cell in which the UE resides is included in a logging area indicated in the area configuration information, determining that the condition is met.

[0027] According to an embodiment of the present disclosure, determining whether a condition for performing logged MDT is met based on a report type and logged MDT configuration information including at least one of a PLMN identity list or area configuration information may include determining whether a cell where the UE resides is included in a logging area indicated in the area configuration information, and determining whether the cell where the UE resides is included in the logging area indicated in the area configuration information may include: receiving a system information block type 1 (SIB1) broadcasted from the cell where the UE resides; and when the area configuration information is included in the logged MDT configuration information, determining whether the cell where the UE resides is included in the logging area indicated in the area configuration information included in the logged MDT configuration information based on the area configuration information and the PLMN identity information list included in the SIB1.

[0028] According to an embodiment of the present disclosure, determining whether a cell in which a UE resides is included in a logging area indicated in area configuration information included in logged MDT configuration information may include: determining whether the PLMN identification information included in the area configuration information is the same as the PLMN identification information corresponding to the first entry of the PLMN identification list corresponding to the first entry of the PLMN identification information list included in SIB1; and determining whether the cell identification information included in the area configuration information is the same as the cell identification information corresponding to the PLMN identification list corresponding to the first entry of the PLMN identification information list included in SIB1.

[0029] According to an embodiment of the present disclosure, determining whether a cell in which a UE resides is included in a logging area indicated in area configuration information included in logged MDT configuration information may include determining whether a new radio (NR) cell global identifier (NCGI) included in PLMN identification information in the area configuration information is the same as the NCGI included in the PLMN identification information list in SIB1.

[0030] According to an embodiment of the present disclosure, logged MDT may be performed in a logging area indicated in the area configuration information.

[0031] According to another embodiment of the present disclosure, an operation method of a base station in a wireless communication system may include: sending an RRC message including logged MDT configuration information to a UE; and receiving from the UE a result of a measurement performed based on the logged MDT configuration information when the UE is in an RRC idle mode or an RRC inactive mode, wherein after performing the measurement based on the configured logging interval when a condition for performing logged MDT is met, the result of the measurement may be stored, whether the condition for performing logged MDT is met may be determined based on the logged MDT configuration information including at least one of a PLMN identity list or area configuration information and a report type configured for the UE, and the report type may be identified based on the logged MDT configuration information.

[0032] According to an embodiment of the present disclosure, in a case where the event type is identified as event L1 based on the logged MDT configuration information, when the UE resides in a cell in a normal residency state, the RPLMN is included in the PLMN identification list stored in the UE, and the cell in which the UE resides is included in the logging area indicated in the area configuration information, it is determined that the conditions for performing logged MDT are met.

[0033] According to an embodiment of the present disclosure, the operating method may further include sending SIB1 including a PLMN identification information list to the UE, and when the area configuration information is included in the logged MDT configuration information, it may be determined based on the area configuration information and the PLMN identification information list included in the SIB1 whether the cell in which the UE resides is included in the logging area indicated in the area configuration information included in the logged MDT configuration information.

[0034] According to an embodiment of the present disclosure, when determining whether the cell in which the UE resides is included in the logging area indicated in the area configuration information included in the logged MDT configuration information, it can be determined whether the PLMN identification information included in the area configuration information is the same as the PLMN identification information corresponding to the first entry of the PLMN identification list corresponding to the first entry of the PLMN identification information list included in SIB1, and it can be determined whether the cell identification information included in the area configuration information is the same as the cell identification information corresponding to the PLMN identification list corresponding to the first entry of the PLMN identification information list included in SIB1.

[0035] According to another embodiment of the present disclosure, a UE operating in a wireless communication system may include: a communicator; and at least one processor, coupled to the communicator and configured to: receive an RRC message from a base station, the RRC message including logged MDT configuration information, the logged MDT configuration information being used to perform logging of measurement results when the UE is in an RRC idle mode or an RRC inactive mode; based on the logged MDT configuration information, identify a report type configured for the UE; based on the report type and the logged MDT configuration information including at least one of a PLMN identity list or area configuration information, determine whether a condition for performing logged MDT is met; when the condition is met, perform measurement based on a configured logging interval; and perform logging of measurement results.

[0036] According to an embodiment of the present disclosure, at least one processor may further be configured to: in a case where the report type is identified as event triggered, identify the event type configured for the UE based on the logged MDT configuration information; and in a case where the event type is identified as event L1, determine that the condition is met when the UE resides in a cell in a normal resident state, the RPLMN is included in the PLMN identification list stored in the UE, and the cell where the UE resides is included in the logging area indicated in the area configuration information.

[0037] According to an embodiment of the present disclosure, at least one processor may also be configured to: receive SIB1 broadcasted from the cell where the UE resides; and when the area configuration information is included in the logged MDT configuration information, determine whether the cell where the UE resides is included in the logging area indicated in the area configuration information included in the logged MDT configuration information based on the area configuration information and the PLMN identification information list included in the SIB1.

[0038] According to an embodiment of the present disclosure, at least one processor may also be configured to: determine whether the PLMN identification information included in the area configuration information is the same as the PLMN identification information corresponding to the first entry in the PLMN identification list corresponding to the first entry in the PLMN identification information list included in SIB1; and determine whether the cell identification information included in the area configuration information is the same as the cell identification information corresponding to the first entry in the PLMN identification list corresponding to the first entry in the PLMN identification information list included in SIB1.

[0039] According to an embodiment of the present disclosure, logged MDT may be performed in a logging area indicated in the area configuration information.

[0040] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. In the following description of the embodiments, descriptions of technical features that are well known in the art to which the present disclosure belongs and are not directly related to the present disclosure are omitted. This is to clearly describe the essence of the present disclosure without making it unclear due to the omission of unnecessary descriptions.

[0041] For the same reason, in the accompanying drawings, some components are exaggerated, omitted or schematically shown. In addition, the size of each element does not fully reflect its actual size. In the accompanying drawings, reference numerals always refer to the same or corresponding elements.

[0042] By referring to the following description of the embodiments and drawings, it will be easier to understand the advantages and features of the present disclosure and the methods for implementing the present disclosure. However, the present disclosure should not be construed as limited to the embodiments set forth below, but may be implemented in many different forms; on the contrary, the present embodiments are provided to make the present disclosure thorough and complete and to fully convey the concept of the present disclosure to those of ordinary skill in the art, and the present disclosure will only be limited by the appended claims. Throughout the specification, the same reference numerals refer to the same elements.

[0043] It will be understood that each box of the flowchart in the accompanying drawings and the combination of boxes of the flowchart can be performed by computer program instructions. These computer program instructions can be loaded into a processor of a general-purpose computer, a special-purpose computer or another programmable data processing device, so the instructions executed by the processor of the computer or other programmable data processing device create a device for performing the functions specified in the (multiple) flowchart boxes. The computer program instructions can also be stored in a computer executable or computer readable memory, which can instruct the computer or another programmable data processing device to implement the function in a specific way, so the instructions stored in the computer executable or computer readable memory can produce a product including an instruction device for performing the functions described in the (multiple) flowchart boxes. The computer program instructions can also be loaded into a computer or another programmable data processing device, so when a series of operations are performed in the computer or other programmable data processing device, the instructions for operating the computer or other programmable data processing device by generating a computer-executed process can provide operations for performing the functions described in the (multiple) flowchart boxes.

[0044] In addition, each frame can represent a module, a fragment or a part of a code including one or more executable instructions for performing (multiple) specified logical functions. It should also be noted that in some alternative embodiments, the functions described in the frame may not appear in order. For example, two frames shown in succession can be performed substantially simultaneously, or these frames can sometimes be performed in reverse order according to the functions corresponding thereto.

[0045] As used herein, the term 'unit' represents a software element or a hardware element, such as a field programmable gate array (FPGA) or an application specific integrated circuit (ASIC), and performs certain operations. However, the term 'unit' is not limited to software or hardware. The 'unit' can be configured to be located in an addressable storage medium, or configured to operate one or more processors. Therefore, the term 'unit' can include, for example, elements, processes, functions, attributes, processes, subroutines, program code segments, drivers, firmware, microcodes, circuits, data, databases, data structures, tables, arrays, and variables such as software elements, object-oriented software elements, class elements, and task elements. The elements and functions provided by the 'unit' can be combined into smaller numbers of elements and 'units', or can be further divided into additional elements and 'units'. In addition, elements and 'units' can be implemented to reproduce one or more central processing units (CPUs) in a device or a secure multimedia card. In addition, in one embodiment, 'unit' can include one or more processors.

[0046] In the following description of the present disclosure, when it is determined that a detailed description of a related known function or configuration may unnecessarily obscure the subject matter of the present disclosure, its description will be omitted. Hereinafter, embodiments of the present disclosure will be described in detail with reference to the accompanying drawings.

[0047] As used in the following description, terms identifying access nodes, terms indicating network entities, terms indicating messages, terms indicating interfaces between network entities, terms indicating various types of identification information, etc. are exemplified for convenience of description. Therefore, the present disclosure is not limited to the terms described later, and other terms representing objects having equivalent technical meanings may be used.

[0048] In the following, for the convenience of description, the present disclosure uses the terms and names defined in the 3rd Generation Partnership Project Long Term Evolution (3GPP LTE) specifications. However, the present disclosure is not limited to these terms and names, but can also be applied to systems that comply with other standards. In the present disclosure, for the convenience of description, eNB can be used interchangeably with gNB. In other words, a base station (BS) described as an eNB can represent a gNB. In addition, the term "terminal" can refer to mobile phones, narrowband IoT (NB-IoT) devices, sensors, and other wireless communication devices.

[0049] Hereinafter, a BS is an entity that allocates resources to a terminal, and may be at least one of a next generation Node B (gNB), an evolved Node B (eNB), a Node B, a BS, a wireless access unit, a controller, or a network node. A terminal may include a user equipment (UE), a mobile station (MS), a cellular phone, a smart phone, a computer, or a multimedia system capable of performing a communication function. However, the terminal is not limited to the above examples.

[0050] In particular, the present disclosure may be applied to the 3GPP New Radio (NR) standard (fifth generation (5G) mobile communication standard). In addition, the present disclosure may be applied to smart services based on 5G communication technology and IoT-related technology (e.g., smart homes, smart buildings, smart cities, smart cars or connected cars, healthcare, digital education, retail commerce, security and safety-related services, etc.). In the present disclosure, for ease of description, eNB may be used interchangeably with gNB. In other words, a BS described as an eNB may represent a gNB. In addition, the term "terminal" may refer to mobile phones, narrowband IoT (NB-IoT) devices, sensors, and other wireless communication devices.

[0051] Wireless communication systems have evolved from providing initial voice-centric services to broadband wireless communication systems that provide high-speed, high-quality packet data services based on communication standards such as 3GPP's High Speed ​​Packet Access (HSPA), LTE or Evolved Universal Terrestrial Radio Access (E-UTRA) and LTE-Advanced (LTE-A), LTE-Pro, 3GPP2's High Speed ​​Packet Data (HRPD), Ultra Mobile Broadband (UMB), and IEEE's 802.16e.

[0052] As a representative example of a broadband wireless communication system, the LTE system adopts an orthogonal frequency division multiplexing (OFDM) scheme for a downlink (DL) and a single carrier frequency division multiple access (SC-FDMA) scheme for an uplink (UL). UL refers to a radio link through which a terminal (UE or MS) transmits data or a control signal to a BS (or eNB), and DL refers to a radio link through which a BS transmits data or a control signal to a terminal.

[0053] In addition, although the embodiments of the present disclosure will be described using LTE, LTE-A, LTE Pro or 5G (or NR, i.e., next generation mobile communication) systems as examples, the embodiments of the present disclosure can be applied to other communication systems with similar technical backgrounds and channel configurations. Those skilled in the art should also understand that the embodiments of the present disclosure are applicable to other communication systems by modifications that do not depart from the scope of the present disclosure.

[0054] Figure 1A The structure of the next generation mobile communication system is shown.

[0055] refer to Figure 1A , the radio access network for the next generation (NR) mobile communication system is composed of a next generation BS (NR Node B, hereinafter referred to as gNB) 1a-10 and an NR core network, and the NR core network may include an access and mobility management function (AMF) 1a-05, but is not limited thereto. A new radio UE (hereinafter referred to as NR UE or UE) 1a-15 can be connected to an external network via the gNB 1a-10 and the AMF 1a-05.

[0056] exist Figure 1AIn the present invention, gNB 1a-10 corresponds to the eNB in ​​the existing LTE system. gNB 1a-10 is connected to the NR UE via a radio channel and can provide better service than the existing Node B (1a-20). In the next generation mobile communication system, because all user services are served through shared channels, an entity that performs scheduling by collecting status information such as the buffer status, available transmission power status, and channel status of the UE is required, and gNB 1a-10 can be responsible for this function. One gNB 1a-10 typically controls multiple cells. In order to provide ultra-high-speed data transmission, the next generation mobile communication system can have a wider bandwidth than the existing maximum bandwidth compared to the existing LTE, and utilize OFDM as the radio access technology (RAT) in combination with additional beamforming technology.

[0057] In addition, according to an embodiment of the present disclosure, NR gNB 1a-10 can apply adaptive modulation and coding (hereinafter referred to as AMC) which determines the modulation scheme and channel coding rate according to the channel state of the UE.

[0058] In addition, according to an embodiment of the present disclosure, AMF 1a-05 can perform functions such as mobility support, bearer configuration, quality of service (QoS) configuration, etc. AMF 1a-05 is responsible for performing various control functions and mobility management of UE, and is connected to multiple BSs. In addition, the next-generation mobile communication system can be interoperable with the existing LTE system, and AMF 1a-05 can be connected to the mobility management entity (MME) 1a-25 through a network interface. MME 1a-25 is connected to eNB 1a-30, which is an existing BS. NR UE supporting LTE-NR dual connection can send and receive data while maintaining a connection not only with gNB 1a-10 but also with eNB 1a-30.

[0059] Figure 1B is a diagram for explaining a radio resource control (RRC) state transition in a next generation mobile communication system.

[0060] In the next generation mobile communication system, there are three RRC states. RRC_CONNECTED mode 1b-05 is an RRC state in which the UE can send and receive data. RRC_IDLE mode 1b-30 is an RRC state in which the UE monitors whether paging is sent to the UE itself. RRC_CONNECTED mode 1b-05 and RRC_IDLE mode 1b-30 are RRC states that are also applicable to the existing LTE system, and the specific technology is the same as that of the existing LTE system.

[0061] In the next generation mobile communication system, RRC_INACTIVE mode 1b-15 is newly defined. In the present disclosure, the RRC_INACTIVE mode 1b-15 newly defined in the next generation mobile communication system may correspond to an RRC inactive state, an inactive mode, a deactivated mode, etc. In RRC_INACTIVE mode (1b-15), the UE context is retained by the BS and the UE, and paging based on the radio access network (RAN) is supported. The features of RRC_INACTIVE mode 1b-15 are listed as follows:

[0062] -Cell reselection mobility;

[0063] - A CN-NR RAN connection (both C / U plane) has been established for the UE;

[0064] -UE AS context is stored in at least one gNB and the UE;

[0065] -Paging is initiated by NR RAN;

[0066] -RAN based notification area is managed by NR RAN;

[0067] - The NR RAN is aware of the RAN-based notification area to which the UE belongs;

[0068] According to an embodiment, a UE in RRC_INACTIVE mode 1b-15 may move to RRC_CONNECTED mode 1b-05 or RRC_IDLE mode 1b-30 by using a specific procedure. According to a recovery procedure, the UE transitions from RRC_INACTIVE mode 1b-15 to RRC_CONNECTED mode 1b-05, and transitions from RRC_CONNECTED mode 1b-05 to RRC_INACTIVE mode 1b-15 (1b-10) by using a release procedure including suspension configuration information. The above-mentioned process 1b-10 may consist of one or more operations, so that one or more RRC messages may be sent and received between the UE and the BS.

[0069] In addition, through the recovery and release procedures, the UE can transition from the RRC_INACTIVE mode 1b-15 to the RRC_IDLE mode 1b-30 (1b-20).

[0070] The transition between the RRC_CONNECTED mode 1b-05 and the RRC_IDLE mode 1b-30 is performed using the existing LTE technology. In other words, the transition between the RRC_CONNECTED mode 1b-05 and the RRC_IDLE mode 1b-30 can be performed through the establishment or release process (1b-25).

[0071] Figure 1C is a diagram for explaining a technique for collecting and reporting cell measurement information according to an embodiment of the present disclosure.

[0072] When building or optimizing a network, a mobile communication service provider (hereinafter referred to as an operator) typically measures the signal strength in an intended service area and performs a process of deploying BSs in the service area or readjusting the deployment based on the measured signal strength. Operators collect cell measurement information in the service area using signal measurement equipment carried on vehicles, which is time-consuming and expensive. The process of collecting cell measurement information is often referred to as drive testing 1c-30 because it typically involves the use of vehicles.

[0073] UE 1c-25 has the function of measuring signals and sending the measurement results to the BS in order to support operations such as cell reselection, switching, and serving cell addition when moving through cells. Therefore, instead of performing the above-mentioned drive test, UE 1c-25 in the service area can be utilized, which can be defined as minimizing drive tests (MDT). The operator can configure MDT operations for specific UEs through various components of the network. In addition, when in RRC_CONNECTED mode, RRC_IDLE mode, or RRC_INACTIVE mode, the UE can collect and store signal strength information from the serving cell and neighboring cells. In addition, the UE can also store various information together, such as location information, time information, signal quality information, etc. The information that the UE can store is not limited to the above examples. When the UE is in RRC_CONNECTED mode, the information stored in the UE can be reported to the network and sent to a specific server.

[0074] The above-mentioned MDT operation can be roughly divided into immediate MDT (Immediate MDT) and recorded MDT.

[0075] The feature of immediate MDT is that the collected information is reported to the network immediately. Since the UE needs to report the collected information to the network immediately, only the UE in RRC_CONNECTED mode can perform immediate MDT. For example, immediate MDT can be performed by applying the existing radio resource management (RRM) measurement process to support operations such as handover and serving cell addition, and location information, time information, etc. can be additionally reported to the network.

[0076] Logged MDT involves storing information collected by the UE without directly reporting the collected information to the network immediately, and then reporting the information stored by the UE after the UE transitions to RRC_CONNECTED mode. As an example, a UE in RRC_IDLE mode that cannot immediately report the collected information to the network can perform logged MDT. A UE in RRC_INACTIVE mode newly introduced in the next generation mobile communication system can perform logged MDT. When a specific UE is in RRC_CONNECTED mode, the network can provide configuration information for performing logged MDT operations to the UE in RRC_CONNECTED mode. In addition, the UE can collect and store the configured information after transitioning to RRC_IDLE mode or RRC_INACTIVE mode.

[0077] Table 1 below is a table summarizing the MDT modes (immediate MDT or logged MDT) that a UE can perform according to its RRC state.

[0078] [Table 1]

[0079] MDT RRC Status Immediate MDT RRC_Connected Recording MDT RRC_Idle, RRC_Inactive

[0080] Figure 1D is a diagram illustrating a method of collecting and reporting cell measurement information according to an embodiment of the present disclosure.

[0081] The UE 1d-05 may transition from the RRC_IDLE or RRC_INACTIVE mode 1d-10 to the RRC_CONNECTED mode 1d-15. The UE 1d-05 in the RRC_CONNECTED mode 1d-15 may collect MDT data and report it to the BS through an immediate MDT operation.

[0082] The UE 1d-05 that has switched to RRC_CONNECTED mode 1d-15 may receive from the BS the logged MDT configuration information (IDLE / INACTIVE MDT configuration) performed in RRC_IDLE or RRC_INACTIVE mode (1d-20). The logged MDT configuration information may be included in a certain RRC message and sent to the UE. After receiving the RRC message, the UE may start a first timer (1d-55).

[0083] The UE may continue to perform the logged MDT operation in the RRC_IDLE or RRC_INACTIVE mode until the first timer expires. The value of the first timer may be included in the logged MDT configuration information. When transitioning to the RRC_IDLE or RRC_INACTIVE mode, the UE performs the logged MDT according to the received logged MDT configuration information (1d-25). The UE may store certain information (1d-30 and 1d-45) collected for each configured time period (e.g., logging interval) 1d-35.

[0084] In addition, if UE 1d-05 has collected valid location information (e.g., global navigation satellite system (GNSS) location information) 1d-40, UE 1d-05 also needs to store the valid location information. If a predetermined time period (e.g., the valid period of the GNSS location) 1d-50 has not passed since the time when the above-mentioned location information was collected, it can be determined that the location information is valid. The predetermined time period 1d-50 for determining whether the location information is valid can be shorter than or equal to the recorded interval (or recording interval) 1d-35.

[0085] Even before the first timer expires, when UE 1d-05 switches to RRC_CONNECTED mode, UE 1d-05 may temporarily stop the logged MDT operation being performed (1d-60). However, even during the interval of RRC_CONNECTED mode, the first timer may continue to run without stopping. In other words, the first timer may continue to run regardless of the RRC state transition. However, when the memory capacity of the UE for storing MDT data is insufficient so that the UE can no longer store data, or when the logged MDT configuration information is released, the first timer may be stopped. For example, when other logged MDT configuration information is received in the serving RAT or another RAT, or when separated or powered off, the UE may release the logged MDT configuration information. During RRC connection establishment or RRC connection recovery, UE 1d-05 may report to the BS that UE 1a-05 has collected the data (MDT data) stored therein (1d-65) by using an RRC establishment complete message or an RRC recovery complete message.

[0086] RRC connection establishment is a process in which UE 1d-05 switches from RRC_IDLE mode to RRC_CONNECTED mode. As described below, RRC connection establishment generally includes three steps and uses three types of RRC messages.

[0087] -Step 1: UE sends an RRC setup request message to the BS.

[0088] -Step 2: The BS sends an RRC setup message to the UE.

[0089] -Step 3: The UE sends an RRC setup complete message to the BS.

[0090] RRC connection recovery is a process in which the UE 1d-05 transitions from RRC_INACTIVE mode to RRC_CONNECTED mode. As described below, RRC connection recovery generally includes three steps and uses three types of RRC messages.

[0091] -Step 1: UE sends an RRC recovery request message to the BS.

[0092] -Step 2: The BS sends an RRC recovery message to the UE.

[0093] -Step 3: The UE sends an RRC recovery complete message to the BS.

[0094] As described above, UE 1d-05 can report information indicating that it has collected information (MDT data) to the BS during RRC connection establishment or RRC connection recovery. In addition, as another example, UE 1d-05 can report information indicating that it has collected information (MDT data) to the target BS during RRC connection reconstruction and handover.

[0095] According to an embodiment of the present disclosure, when logged MDT is configured but no information has been collected and stored, UE1d-05 omits the above-mentioned reporting process.

[0096] When receiving a report indicating that UE 1d-05 has the collected information (MDT data), the BS can request UE 1d-05 to report the MDT data stored by UE 1d-05 when necessary. The unreported MDT data needs to be continuously stored by UE 1d-05 for a predetermined period of time. If the UE switches back to RRC_IDLE mode or RRC_INACTIVE mode and the first timer has not expired, UE 1d-05 can resume logged MDT operation (1d-70).

[0097] When the first timer expires, the UE 1d-05 may stop the logged MDT operation (1d-75). The UE 1d-05 that has stopped the logged MDT operation may start a second timer (1d-80) and retain the stored MDT data until the second timer expires. After the second timer expires, it may be determined by the UE implementation whether to discard the stored MDT data. According to an embodiment of the present disclosure, the value of the second timer may be included in the logged MDT configuration information, or a predefined value may be applied without configuration.

[0098] When UE 1d-05 switches back to RRC_CONNECTED mode, UE 1d-05 may report to the BS that it has the collected information (MDT data) stored therein (1d-85). Thereafter, the BS may request UE 1d-05 to report the MDT data stored by UE 1d-05 by using a certain RRC message (1d-90). Then, UE 1d-05 may receive (or include) the stored MDT data in an RRC message and report the RRC message to the BS (1d-95).

[0099] Figure 1E is a flowchart of operations for collecting and reporting cell measurement information according to an embodiment of the present disclosure.

[0100] UE 1e-05 may establish a connection with BS (e.g., gNB) 1e-10 (1e-15). UE 1e-05 may provide UE capability information to BS 1e-10 (1e-20) and indicate whether UE 1e-05 supports MDT operation and the frequency at which UE 1e-05 may perform measurement. BS 1e-10 may include configuration information required to perform logged MDT operation in an RRC message and send it to UE 1e-05 (1e-25). For example, the configuration information may include at least one of the following information:

[0101] - Track reference information

[0102] - Tracking session reference information

[0103] - Trace Collection Entity (TCE) ID information: The BS sends the MDT data information reported from the UE to a data server specified by the TCE ID.

[0104] - Absolute time information: provides the absolute time in the current cell of the logged MDT configuration information

[0105] - Area configuration: This indicates information about an area in which measurement information can be collected and stored through the logged MDT operation, and the area is expressed in units of cells. This information may also include information about the RAT in which the measurement information should be collected. The list included in the RAT information may be a blacklist or a whitelist. If the list is a blacklist, cell measurement information is collected for RATs not included in the list. If the list is a whitelist, cell measurement information is not collected for RATs not included in the list.

[0106] - Logging duration: This is the value of the first timer mentioned above, and when the first timer runs, the UE performs logged MDT operation in RRC_IDLE or RRC_INACTIVE mode.

[0107] - Logging Interval: This is the period during which the collected information is stored.

[0108] - plmn-IdentityList (ie, MDT PLMN list): This indicates public land mobile network (PLMN) list information, and includes information on PLMNs in which a logged MDT operation and reporting of whether MDT data is stored and reporting of MDT data can be performed.

[0109] - An indicator indicating whether the UE performs the logged MDT operation in RRC_IDLE mode, RRC_INACTIVE mode, or both modes. For example, by using this indicator, the RRC state in which the logged MDT operation is performed can be indicated. As another example, in the absence of this indicator, it can be defined that the UE always performs the logged MDT operation in the RRC_IDLE mode and the RRC_INACTIVE mode. The UE performs the logged MDT operation only in the RRC state indicated by the indicator.

[0110] -Indicator indicating whether to collect and store beam level measurement information. Beam antennas may be applied in next generation mobile communication systems. As an example, in the absence of this indicator, it may be defined that for frequencies performing beam-based operations, beam level measurements are always collected and stored.

[0111] - Information about the maximum number of beams collected or stored, and the minimum signal strength information of the stored beams. The UE may omit the storage of information about beams whose signal strength is less than the minimum signal strength among the stored beams. If the signal strength of all beams is less than the configured minimum signal value, the UE may store information about the beam with the strongest signal strength among the beams, or include an indicator indicating that the signal strength of all beams is less than the configured minimum signal value.

[0112] - An indicator indicating whether an MDT retrieval operation can be triggered in two-step RRC recovery.

[0113] After receiving the logged MDT configuration information, the UE 1e-05 may start a first timer (1e-30). The value of the first timer may be configured to be equal to the value of the logging duration.

[0114] BS 1e-10 may move UE 1e-05 to RRC_IDLE or RRC_INACTIVE mode by using an RRC release message (1e-35). Depending on the RRC state to which UE 1e-05 moves, the RRC release message may include configuration information for operation of UE 1e-05 in the selected RRC state.

[0115] While the first timer is running, UE 1e-05 may perform a logged MDT operation in RRC_IDLE or RRC_INACTIVE mode (1e-40).

[0116] According to an embodiment of the present disclosure, UE 1e-05 can measure the signal strength of the serving cell and the neighboring cell and obtain location information. When beam level measurement is configured, UE 1e-05 can collect and store the signal strength values ​​of beams greater than the configured minimum value (minimum signal value) in the serving cell and the neighboring cell. The maximum number of beams that can be stored can be configured or predefined. In the present disclosure, the signal strength can be a reference signal received power (RSRP), a reference signal received quality (RSRQ), or a signal to interference plus noise ratio (SINR), but is not limited thereto.

[0117] UE 1e-05 may store the collected information for each logged interval.

[0118] When the first timer expires (1e-45), UE 1e-05 may stop the logged MDT operation (1e-50).

[0119] When UE 1e-05 is in RRC_IDLE or RRC_INACTIVE mode via the RRC release message in the above operation 1e-35 and receives RAN paging or core network (CN) paging from the BS, or mobile originated (MO) data transmission is activated, UE 1e-05 can initiate an establishment or recovery procedure for transitioning from RRC_IDLE or RRC_INACTIVE mode to RRC_CONNECTED mode.

[0120] The setup or recovery process can consist of the following steps:

[0121] -Step 1: UE 1e-05 sends an RRC establishment request message or an RRC recovery request message to BS 1e-10 (1e-55).

[0122] -Step 2: BS 1e-10 sends an RRC setup message or an RRC resume message to UE 1e-05 (1e-60).

[0123] -Step 3: UE 1e-05 sends an RRC setup complete message or an RRC recovery complete message to BS 1e-10 (1e-65).

[0124] According to an embodiment of the present disclosure, the UE 1e-05 may include an indicator indicating the availability of the MDT data stored therein in the RRC Setup Complete or RRC Recovery Complete message.

[0125] When receiving the RRC setup complete message, the BS 1e-10 may request the UE 1e-05 to report MDT data by using a certain RRC message when necessary (1e-70). When receiving the request from the BS 1e-10, the UE 1e-05 may report MDT data to the BS 1e-10 by using a certain RRC message (1e-75).

[0126] Figure 1F is a diagram for explaining a radio link monitoring (RLM) operation according to an embodiment of the present disclosure.

[0127] The physical layer of the UE may measure the DL signal quality (1f-05) based on the cell-specific reference signal (CRS) of the serving cell. The physical layer of the UE may determine whether the DL signal quality is lower than (or less than) Qout (1f-10), where Qout is a specific threshold. In this case, for example, the threshold may represent a signal quality value corresponding to a specific block error rate (BLER) measured in a physical downlink control channel (PDCCH).

[0128] If the DL signal quality is below a certain threshold Qout, the physical layer may send an 'out-of-sync' indication to a higher layer. In LTE technology, this operation is called RLM. If the 'out-of-sync' indication is sent to a higher layer more than a certain number of times, the higher layer may start a specific timer and declare a radio link failure (RLF) when the timer expires (1f-15).

[0129] Figure 1G is a diagram for explaining a RLF operation according to an embodiment of the present disclosure.

[0130] As described above, RLF may be declared according to the result of the RLM operation. The physical layer of the UE may determine whether the DL signal quality is lower than a specific threshold Qout for each specific period (e.g., Qout evaluation period) based on the CRS of the serving cell. If the DL signal quality is lower than the specific threshold Qout, the physical layer may send an 'out-of-sync' indication to a higher layer.

[0131] When the first 'out-of-sync' indication is sent to the higher layer (1g-05), and then the 'out-of-sync' indication is sent to the higher layer a specific number of times (e.g., N310), the higher layer may start a specific timer (e.g., timer T310) (1g-10).

[0132] The physical layer may also determine whether the DL signal quality is higher than a specific threshold Qin based on the CRS of the serving cell. If the DL signal quality is higher than a specific threshold Qin, the physical layer may send an 'in-sync' indication to a higher layer. When the 'in-sync' indication is sent to the higher layer a specific number of times, the higher layer may stop the running T310 timer. If the T310 timer is not stopped but expires, the higher layer may declare RLF (1g-15).

[0133] After the RLF is declared, the UE may start another timer T311. The UE may search for a new suitable cell. If the UE fails to find a new suitable cell before the timer T311 expires, the UE may transition to RRC_IDLE mode (1g-25).

[0134] If the UE finds a new suitable cell before the timer T311 expires, the UE may start the timer T301 and perform a reestablishment procedure with the new suitable cell (1g-20).

[0135] According to an embodiment of the present disclosure, if the reestablishment is not successfully completed before the timer T301 expires, the UE may move to the RRC_IDLE mode (1g-30).

[0136] According to an embodiment of the present disclosure, if the reestablishment is successful, the UE may maintain the RRC_CONNECTED mode for the cell (e.g., a new suitable cell). RLF may be announced through an RLM operation or according to another condition. For example, RLF may also be announced when a random access (RA) fails (1g-35).

[0137] Furthermore, RLF may be declared in the case where a packet is not successfully transmitted even though the maximum number of retransmissions has been reached in the Radio Link Control (RLC) layer (1g-40). The operations of timers T301 and T311 are described in Table 2 below.

[0138] [Table 2]

[0139]

[0140] In the case of a handover failure, RLF is also declared. When receiving the RRCConnectionReconfiguration message (1g-45) including the mobilityControlInfo information element (IE) and the handover configuration information, the UE may start timer T304. The configured time value of timer T304 may be provided by the mobilityControlInfo. If the RA with the target cell is not successfully completed before the expiration of timer T304, the UE may consider this to be a handover failure and declare RLF (1g-50).

[0141] A plurality of predetermined information collected by the UE when RLF occurs is useful for optimizing the cell area. Therefore, when RLF occurs, a plurality of information is stored in the UE and then reported to the BS when the UE successfully switches to the RRC_CONNECTED mode. In this case, reporting the predetermined information stored in the UE to the BS is called RLF reporting, and the information reported at this time is as follows. In this case, information related to the RA process can also be stored together.

[0142] -plmn-IdentityList

[0143] -measResultLastServCell

[0144] -measResultNeighCells

[0145] -locationInfo

[0146] -failedPCellId

[0147] -previousPCellId

[0148] -timeConnFailure

[0149] -Cell Radio Network Temporary Identifier (C-RNTI) used in the source PCell

[0150] -connectionFailureType

[0151] -absoluteFrequencyPointA: absolute frequency position of the reference resource block (common RB 0)

[0152] -locationAndBandwidth: The frequency domain location and bandwidth of the bandwidth part (BWP) associated with the random access resource used by the UE

[0153] -subcarrierSpacing: The subcarrier spacing used in the BWP associated with the random access resource used by the UE

[0154] -msg1-FrequencyStart: The offset of the lowest physical random access channel (PRACH) transmission opportunity in the frequency domain relative to PRB 0 of the UL BWP

[0155] -msg1-SubcarrierSpacing: Subcarrier spacing of PRACH resources

[0156] -msg1-FDM: the number of PRACH transmission opportunities that are FDMed in one time instance

[0157] -raPurpose: RA scenario that triggers RA report entry

[0158] perRAInfoList: Detailed information about each RA attempt in the RA attempt (in chronological order of the RA attempts), such as the synchronization signal block (SSB) index associated with the preamble transmission, the number of preamble transmissions per SSB, whether contention occurred, etc.

[0159] When the UE transitions to RRC_CONNECTED mode through the RRC establishment or RRC recovery procedure, the UE may report the availability of the stored RLF report to the BS by using a certain RRC message such as an RRCSetupComplete message, an RRCResumeComplete message, etc. (1g-55).

[0160] The BS may indicate to the UE that the UE should report the RLF report by using a UEInformationRequest message (1g-60). The UE may report a UEInformationResponse message including the RLF report to the BS (1g-65).

[0161] Figure 1H is a diagram for explaining an RA report according to an embodiment of the present disclosure.

[0162] For a successfully completed RA, the UE may store the RA related information in VarRA-Report (1h-05), where VarRA-Report is an internal variable in the UE. This is called an RA report. The information related to the RA report is as follows.

[0163] -CellId: CGI of the cell that performs the associated RA procedure

[0164] -absoluteFrequencyPointA: absolute frequency position of the reference resource block (common RB 0)

[0165] -locationAndBandwidth: The frequency domain location and bandwidth of the BWP associated with the random access resource used by the UE

[0166] -subcarrierSpacing: The subcarrier spacing used in the BWP associated with the random access resource used by the UE

[0167] -msg1-FrequencyStart: The offset of the lowest PRACH transmission opportunity in the frequency domain relative to PRB 0 of the UL BWP

[0168] -msg1-SubcarrierSpacing: Subcarrier spacing of PRACH resources

[0169] -msg1-FDM: the number of PRACH transmission opportunities that are FDMed in one time instance

[0170] -raPurpose: RA scenario that triggers RA report entry

[0171] -perRAInfoList: Detailed information about each RA attempt in the RA list, sorted by chronological order of the RA attempts

[0172] In addition, when storing the above information, if the EPLMN information has been stored, the UE may store an equivalent PLMN (EPLM) list, otherwise, store the selected PLMN information together.

[0173] When another RA procedure is successfully completed after storing the RA information, the UE may store information related to the newly successful RA (1h-10). In this case, if the registered PLMN (RPLMN) is included in the stored PLMN information, the stored PLMN information may be updated with the currently stored EPLMN information for storage. If the RPLMN is not included in the stored PLMN information, all information stored in the VarRA-Report may be discarded.

[0174] According to an embodiment of the present disclosure, the UE may store up to 8 RA reports. When eight RA reports have been stored and a new RA process is successfully completed, the UE may delete the oldest RA report and store information related to the new successful RA process (1h-15).

[0175] After the UE transitions to the RRC_CONNECTED mode, the BS may request the UE for the RA report information stored in the UE using a certain RRC message (1h-20). At this time, if the UE has stored the RA report and the RPLMN is included in the stored PLMN information, the UE may report the stored RA report to the BS using a certain RRC message (1h-25). All reported RA report information may be discarded from the VarRA report.

[0176] Fig. 1I is a flowchart of an operation of collecting and reporting cell measurement information by considering PLMN and area configuration according to an embodiment of the present disclosure.

[0177] UE 1i-05 establishes a connection (RRC connection) with BS 1i-10 (1i-15). UE 1i-05 may provide UE capability information to BS 1i-10 (1i-20) and indicate whether UE 1i-05 supports MDT operation and the frequency at which UE 1i-05 may perform measurements. BS 1i-10 may include configuration information required to perform logged MDT operation in a certain RRC message and send it to UE 1i-05 (1i-25). For example, the configuration information may include at least one of the following information:

[0178] - Track reference information

[0179] - Tracking session reference information

[0180] - Trace Collection Entity (TCE) ID information: The BS sends the MDT data information reported from the UE to a data server specified by the TCE ID.

[0181] - Absolute time information: provides the absolute time in the current cell of the logged MDT configuration information

[0182] - Area configuration: This indicates information about an area capable of collecting and storing measurement information through MDT operation, and the area is indicated in a cell unit, a tracking area code (TAC) unit, or a tracking code identity (TAI) unit. The Abstract Syntax Notation One (ASN.1) structure of the area configuration is as follows.

[0183]

[0184] When the area configuration is indicated in units of cells, it is indicated by the NR Cell Global Identifier (NCGI) value and consists of a plmn-Identity (a field indicating a PLMN ID) and a cellIdentity. The logging area can also be represented by TAC or TAI. TAI consists of a plmn-Identity and a TAC.

[0185]

[0186] - Logging duration: This is the value of the first timer mentioned above, and when the first timer runs, the UE performs logged MDT operation in RRC_IDLE or RRC_INACTIVE mode.

[0187] - Logging Interval: This is the period during which the collected information is stored.

[0188] - plmn-IdentityList (ie, MDT PLMN list): This is PLMN list information, and includes information on PLMNs in which logged MDT operates and whether to store reporting of MDT data and reporting of MDT data is allowed.

[0189] - An indicator indicating whether the UE performs the logged MDT operation in RRC_IDLE mode, RRC_INACTIVE mode, or both modes. For example, by using this indicator, the RRC state in which the logged MDT operation is performed can be indicated. As another example, in the absence of this indicator, it can be defined that the UE always performs the logged MDT operation in the RRC_IDLE mode and the RRC_INACTIVE mode. The UE performs the logged MDT operation only in the RRC state indicated by the indicator.

[0190] -Indicator indicating whether to collect and store beam level measurement information. Beam antennas can be applied in next generation mobile communication systems. For example, in the absence of this indicator, it can be defined that for frequencies performing beam-based operations, beam level measurements are always collected and stored.

[0191] -Information about the maximum number of beams collected or stored, and the minimum signal strength information of the stored beams. The UE may omit the storage of information about beams whose signal strength is less than the minimum signal strength among the stored beams. If the signal strength of all beams is less than the configured minimum signal value, the UE may store information about the beam with the strongest signal strength among the beams, or include an indicator indicating that the signal strength of all beams is less than the set minimum signal value.

[0192] -Indicator indicating whether an MDT retrieval operation can be triggered in two-step RRC recovery.

[0193] -reportType: an indicator indicating whether the MDT is periodic logging MDT or event-triggered periodic logging MDT. In the case of event-triggered periodic logging MDT, only one of the out-of-coverage and event A2 conditions can be configured.

[0194] When receiving the logged MDT configuration information, UE 1i-05 may start a first timer (1i-30). The value of the first timer may be configured to be equal to the value of the logging duration.

[0195] BS 1i-10 can move UE 1i-05 to RRC_IDLE or RRC_INACTIVE mode by using RRC release message (1i-35). Depending on the RRC state to which UE 1i-05 moves, the RRC release message may include configuration information for the operation of UE 1i-05 in the selected RRC state.

[0196] If the first timer is running, UE 1i-05 performs periodic logged MDT or event-triggered logged MDT in RRC_IDLE or RRC_INACTIVE mode when all of the following conditions are met (1i-40).

[0197] - If the UE camps on the NR cell in normal camping state,

[0198] - if the UE's RPLMN is configured as above and is included in the plmn-IdentityList stored by the UE, and

[0199] -If the NR cell in which the UE is currently camped belongs to the area indicated by the area configuration, in order to check whether the NR cell belongs to the area indicated by the area configuration, the UE receives the system information block type 1 (SIB1) broadcasted from the NR cell. A list of PLMNs supported by the corresponding cell is received in SIB1. In the NR system, there may be multiple NCGIs indicating one cell. The NR BS can store the ID information of the NR cell in the PLMN-IdentityInfoListIE in SIB1, as described below, and provide it to the UE. The cellIdentity field corresponding to each PLMN and multiple PLMNs can be provided to the operator. The NCGI is a combination of the PLMN and the NCI indicated by its corresponding cellIdentity. Therefore, there may be several NCGIs indicating one cell. The reason for developing the NR system so that each operator can have multiple cell IDs is to efficiently operate cells when the network is shared between operators. For each PLMN-IdentityInfo, a TAC value is included.

[0200] -PLMN-IdentityInfoList

[0201] The IE PLMN-IdentityInfoList includes a list of PLMN identity information.

[0202] PLMN-IdentityInfoList Information Element

[0203]

[0204] Therefore, as shown in Table 3 below, it is necessary to define which value among the multiple NCGIs and multiple PLMNs supported by the NR cell must be compared with the cell and TAI indicated by the area configuration.

[0205] [Table 3]

[0206]

[0207] The embodiments of the present disclosure set forth below are described.

[0208] Example 1

[0209] If CellGlobalIdList is configured in the regional configuration, the UE determines whether the combination of PLMN-identity and CellIdentity indicated in CellGlobalIdList (NCGI) is the same as the specific combination of PLMN-identity and CellIdentity broadcast in SIB1. In this case, the PLMN-identity is the first PLMN-identity of the first PLMN-IdentityInfo in the PLMN-IdentityInfoList, and the CellIdentity is the cellIdentity included in the PLMN-IdentityInfo including the PLMN-Identity.

[0210] If TrackingAreaCodeList is configured in the area configuration, the UE determines whether the TAC in the TrackingAreaCodeList is the same as the TAC included in a certain PLMN-IdentityInfo broadcasted in SIB 1. In this case, the PLMN-IdentityInfo is the first PLMN-IdentityInfo in the PLMN-IdentityInfoList.

[0211] If TrackingAreaIdentityList is configured in the area configuration, the UE determines whether the combination of PLMN-identity and TAC (TAI) indicated in TrackingAreaCodeList is the same as the specific combination of PLMN-identity and TAC broadcast in SIB1. In this case, the PLMN-identity is the first PLMN-identity of the first PLMN-IdentityInfo in the PLMN-IdentityInfoList, and the TAC is the TAC included in the PLMN-IdentityInfo including the PLMN-identity.

[0212] Embodiment 2:

[0213] If CellGlobalIdList is configured in the area configuration, the UE determines whether the combination of PLMN-identity and CellIdentity indicated in CellGlobalIdList (NCGI) is the same as any combination of PLMN-identity and CellIdentity broadcast in SIB1. If the combination is the same as at least one combination of PLMN-identity and CellIdentity in SIB1, the UE considers that the cell is included in the configured area.

[0214] If TrackingAreaCodeList has been configured in the area configuration, the UE determines whether the TAC in the TrackingAreaCodeList is the same as the TAC included in any PLMN-IdentityInfo broadcast in SIB 1. In the case that the TAC is the same as at least one combination, the UE considers that the cell belongs to the configured area.

[0215] If TrackingAreaIdentityList has been configured in the area configuration, the UE determines whether the combination of PLMN-identity and TAC (TAI) indicated in TrackingAreaIdentityList is the same as any combination of PLMN-identity and TAC broadcast in SIB1. If this combination is the same as at least one combination of PLMN-identity and TAC in SIB1, the UE considers that the cell belongs to the configured area.

[0216] When the first timer expires (1i-45), the UE 1i-05 may stop the logged MDT operation (1i-50).

[0217] When UE 1i-05 is in RRC_IDLE or RRC_INACTIVE mode via the RRC release message in the above operation 1i-35 and receives RAN or CN paging from the BS or MO data transmission is activated, UE 1i-05 can initiate an establishment or recovery procedure for transitioning from RRC_IDLE or RRC_INACTIVE mode to RRC_CONNECTED mode.

[0218] The setup or recovery process can consist of the following steps:

[0219] -Step 1: UE 1i-05 sends an RRC establishment request message or an RRC recovery request message to BS 1i-10 (1i-55).

[0220] -Step 2: BS 1i-10 sends an RRC setup message or an RRC resume message to UE 1i-05 (1i-60).

[0221] -Step 3: UE 1i-05 sends an RRC setup complete message or an RRC recovery complete message to BS 1i-10 (1i-65).

[0222] According to an embodiment of the present disclosure, UE 1i-05 may contain, in an RRC Setup Complete or RRC Recovery Complete message, an indicator indicating the availability of MDT data stored therein.

[0223] When receiving the RRC setup complete message, the BS 1i-10 may request the UE 1i-05 to report the MDT data by using a certain RRC message when necessary (1i-70). Upon receiving the request from the BS 1i-10, the UE 1i-05 may report the MDT data to the BS 1i-10 by using a certain RRC message (1i-75).

[0224] Figure 1J is a flowchart of an operation of a UE storing cell measurement information by considering RPLMN and area configuration according to an embodiment of the present disclosure.

[0225] In operation 1j-05, the UE receives a loggedMeasurementConfiguration message from the BS.

[0226] In operation 1j-10, the UE enters RRC_IDLE or RRC_INACTIVE mode.

[0227] In operation 1j-15, the UE determines the reportType included in the loggedMeasurementConfiguration message.

[0228] In operation 1j-20, if reportType is configured as periodic, the UE determines whether all of the following conditions are met.

[0229] - If the UE camps on the NR cell in normal camping state,

[0230] - if the UE's RPLMN is configured and included in the plmn-IdentityList stored by the UE, and

[0231] - If the NR cell on which the UE is camping belongs to the area indicated by the area configuration

[0232] In operation 1j-25, if all the above conditions are met, the UE collects and stores the defined information at the configured logging interval.

[0233] In operation 1j-30, if reportType is configured as event triggered, the UE determines the type of the event.

[0234] In operation 1j-35, if the event is out of coverage, the UE collects and stores the defined information at a configured logging interval when the UE is in any cell selection state.

[0235] In operation 1j-40, if the event is eventL1, the UE determines whether all the following conditions are met. Here, eventL1 indicates the condition that the signal level (reference signal received power (RSRP)) of the serving cell is lower than a certain threshold, which is the same as the condition of event A2 in RRC_CONNECTED mode cell measurement.

[0236] - If the UE camps on the NR cell in normal camping state,

[0237] - if the UE's RPLMN is configured and included in the plmn-IdentityList stored by the UE, and

[0238] - If the NR cell on which the UE is camping belongs to the area indicated by the area configuration

[0239] In operation 1j-45, if all the above conditions are met, the UE collects and stores the defined information at the configured logging interval.

[0240] Figure 1K is a flowchart of an operation of a UE reporting location information according to an embodiment of the present disclosure.

[0241] In operation 1k-05, the UE receives a loggedMeasurementConfiguration message from the BS.

[0242] In operation 1k-10, the UE enters RRC_IDLE or RRC_INACTIVE mode.

[0243] In operation 1k-15, the UE performs logged MDT according to the configuration.

[0244] In operation 1k-20, the UE determines whether bt-NameList, wlan-NameList, or sensor-NameList is included in the loggedMeasurementConfiguration message.

[0245] In operation 1k-25, if bt-NameList, wlan-NameList, or sensor-NameList is not included in the loggedMeasurementConfiguration message, the UE includes the following information in the LocationInfo IE only for valid information.

[0246] - Include valid GNSS information in the commonLocationInfo IE of the LocationInfo IE

[0247] - Include valid Bluetooth information in the bt-LocationInfo IE of the LocationInfo IE in descending order of RSSI of Bluetooth beacons

[0248] - Include valid WLAN information in the wlan-LocationInfo IE of the LocationInfo IE in descending order of RSSI of the WLAN AP

[0249] - Include valid sensor information in the sensor-location info IE of the LocationInfo IE

[0250] In operation 1k-30, if bt-NameList, wlan-NameList, or sensor-NameList is included in the loggedMeasurementConfiguration message, the UE includes the following information in the LocationInfo IE only for valid information.

[0251] - Include valid GNSS information in the commonLocationInfo IE of the LocationInfo IE

[0252] - Include valid Bluetooth information in the bt-LocationInfo IE of the LocationInfo IE in descending order of RSSI of Bluetooth beacons

[0253] - Include valid WLAN information in the wlan-LocationInfo IE of the LocationInfo IE in descending order of RSSI of the WLAN AP

[0254] - Include available Bluetooth information in the sensor-LocationInfo IE in the LocationInfo IE

[0255] In operation 1k-35, the UE additionally includes the following information in the logMeasInfo IE.

[0256] - Include valid measurement results among the measurement results of the APs in the WLAN-NameList configured in the logMeasResultListWLAN IE of the logMeasInfo IE, and include WLAN information in descending order of RSSI of the WLAN APs

[0257] - Include valid measurement results among the measurement results of the AP in the configuration BT-NameList in the logMeasResultListBT IE of the logMeasInfo IE, and include Bluetooth information in descending order of RSSI of Bluetooth beacons

[0258] - Include valid measurement results in the AP measurement results in the Sensor-NameList configured in the Sensor-LocationInfo IE of the logMeasInfo IE

[0259] Therefore, when bt-NameList, wlan-NameList, or sensor-NameList is provided, it is used for the purpose of self-organizing network (SON) and for simple location information, and is included in IEs other than LocationInfo IE.

[0260] Figure 1L is a block diagram of an internal configuration of a UE according to an embodiment of the present disclosure.

[0261] refer to Figure 1L , the UE may include a radio frequency (RF) processor 11-10, a baseband processor 11-20, a storage device 11-30, and a controller 11-40. However, the UE is not limited to the above example, but may include more Figure 1L Fewer or more components may be shown.

[0262] The RF processor 11-10 can perform functions for sending and receiving signals via a radio channel, such as signal conversion and amplification between frequency bands. In detail, the RF processor 11-10 can up-convert the baseband signal from the baseband processor 11-20 into an RF signal, and then send the RF signal via an antenna, and down-convert the RF signal received via the antenna into a baseband signal. For example, the RF processor 11-10 may include a transmission filter, a reception filter, an amplifier, a mixer, an oscillator, a digital-to-analog converter (DAC), an analog-to-digital converter (ADC), etc. However, the RF processor 11-10 is not limited to the above examples. Although in Figure 1L Only one antenna is shown in the figure, but the UE may include multiple antennas. The RF processor 11-10 may also include multiple RF chains. In addition, the RF processor 11-10 may perform beamforming. For beamforming, the RF processor 11-10 may adjust the phase and amplitude of each of the signals sent and received through multiple antennas or antenna elements. In addition, the RF processor 11-10 may perform multiple-input multiple-output (MIMO) operations and receive several layers during MIMO operations.

[0263] The baseband processor 11-20 can perform the conversion function between the baseband signal and the bit string according to the physical layer standard of the system. For example, when sending data, the baseband processor 11-20 can generate complex symbols by encoding and modulating the sending bit string. In addition, when receiving data, the baseband processor 11-20 can reconstruct the received bit string by demodulating and decoding the baseband signal from the RF processor 11-10. For example, according to the OFDM scheme, when sending data, the baseband processor 11-20 can generate complex symbols by encoding and modulating the sending bit string, map the complex symbols to subcarriers, and then generate OFDM symbols through inverse fast Fourier transform (IFFT) operation and cyclic prefix (CP) insertion. In addition, when receiving data, the baseband processor 11-20 can divide the baseband signal from the RF processor 11-10 into OFDM symbols, recover the signal mapped to the subcarrier through FFT operation, and then reconstruct the received bit string through demodulation and decoding.

[0264] The baseband processor 11-20 and the RF processor 11-10 can send and receive signals as above. Therefore, the baseband processor 11-20 and the RF processor 11-10 can be referred to as a transmitter, a receiver, a transceiver or a communicator. In addition, at least one of the baseband processor 11-20 and the RF processor 11-10 may include multiple communication modules to support multiple different RATs. In addition, at least one of the baseband processor 11-20 and the RF processor 11-10 may include different communication modules to process signals in different frequency bands. For example, different RATs may include wireless local area network (WLAN) technology (e.g., Institute of Electrical and Electronics Engineers (IEEE) 802.11), cellular network technology (e.g., LTE), etc. In addition, different frequency bands may include ultra-high frequency (SHF) bands (e.g., 2.5GHz and 5GHz) and millimeter wave (mm) bands (e.g., 60GHz). The UE may send and receive signals to and from the BS via the baseband processor 11-20 and the RF processor 11-10, and the signal may include control information and data.

[0265] The storage device 11-30 can store basic programs, applications, and data, such as configuration information for UE operation. Specifically, the storage device 11-30 can store basic programs, applications, and data information, such as configuration information for the above-mentioned operations of the UE. The storage device 11-30 can also provide stored data at the request of the controller 11-40.

[0266] The storage 11-30 may be composed of a storage medium such as a read-only memory (ROM), a random access memory (RAM), a hard disk, a compact disk (CD)-ROM, and a digital versatile disk (DVD), or a combination thereof. In addition, the storage device 11-30 may include a plurality of memories.

[0267] The controller 11-40 can control all operations of the UE. For example, the controller 11-40 can send or receive signals via the baseband processor 11-20 and the RF processor 11-10. The controller 11-40 can also write data to the storage 11-40 and read data from the storage 11-40. To this end, the controller 11-40 may include at least one processor. For example, the controller 11-40 may include a communication processor (CP) for performing communication control and an application processor (AP) for controlling a higher layer such as an application. In addition, according to an embodiment of the present disclosure, the controller 11-40 may include a multi-connection processor 11-42, which performs processing for operating in a multi-connection mode. In addition, at least one component in the UE may be implemented as a single chip.

[0268] Figure 1M is a block diagram of a configuration of a BS according to the present disclosure.

[0269] refer to Figure 1M , the BS may include an RF processor 1m-10, a baseband processor 1m-20, a backhaul communicator 1m-30, a storage device 1m-40, and a controller 1m-50. However, the BS is not limited to the above example, but may include more Figure 1M Fewer or more components may be shown.

[0270] The RF processor 1m-10 may perform functions for transmitting and receiving signals via a radio channel, such as signal conversion and amplification between frequency bands. In detail, the RF processor 1m-10 may up-convert a baseband signal from the baseband processor 1m-20 into an RF signal, and then transmit the RF signal via an antenna, and down-convert an RF signal received via an antenna into a baseband signal. For example, the RF processor 1m-10 may include a transmission filter, a reception filter, an amplifier, a mixer, an oscillator, a DAC, an ADC, and the like. Although in Figure 1M Only one antenna is shown in the figure, but the RF processor 1m-10 may include multiple antennas.

[0271] In addition, the RF processor 1m-10 may include multiple RF chains. In addition, the RF processor 1m-10 may perform beamforming. For beamforming, the RF processor 1m-10 may adjust the phase and amplitude of each of the signals transmitted and received through multiple antennas or antenna elements. In addition, the RF processor 1m-10 may perform DLMIMO operations by transmitting one or more layers.

[0272] The baseband processor 1m-20 can perform the conversion function between the baseband signal and the bit string according to the physical layer standard. For example, when sending data, the baseband processor 1m-20 can generate complex symbols by encoding and modulating the sending bit string. In addition, when receiving data, the baseband processor 1m-20 can reconstruct the received bit string by demodulating and decoding the baseband signal from the RF processor 1m-10. For example, according to the OFDM scheme, when sending data, the baseband processor 1m-20 can generate complex symbols by encoding and modulating the sending bit string, map the complex symbols to subcarriers, and then generate OFDM symbols through IFFT operation and CP insertion. In addition, when receiving data, the baseband processor 1m-20 can divide the baseband signal from the RF processor 1m-10 into OFDM symbols, restore the signal mapped to the subcarrier through FFT operation, and then reconstruct the received bit string through demodulation and decoding. The baseband processor 1m-20 and the RF processor 1m-10 can send and receive signals as above. Therefore, the baseband processor 1m-20 and the RF processor 1m-10 can be referred to as a transmitter, a receiver, a transceiver, a communicator, or a wireless communicator. The BS can send and receive signals to and from the UE via the baseband processor 1m-20 and the RF processor 1m-10, and the signals can include control information and data.

[0273] The backhaul communicator 1m-30 may provide an interface for communicating with other nodes in the network. For example, the backhaul communicator 1m-30 may convert a bit string sent from the master BS to another node such as the secondary BS and the CN into a physical signal, and convert a physical signal received from the other node into a bit string.

[0274] The storage device 1m-40 stores basic programs, applications, and data, such as configuration information for BS operation. Specifically, the storage device 1m-40 may store information about the bearers assigned to the connected UEs, measurement results reported by the connected UEs, and the like. In addition, the storage device 1m-40 may store information serving as a criterion for determining whether to provide multiple connections to the UE or terminate multiple connections from the UE. The storage device 1m-40 may also provide stored data at the request of the controller 1m-50. The storage device 1m-40 may be composed of a storage medium such as a ROM, a RAM, a hard disk, a CD-ROM, and a DVD, or a combination thereof. In addition, the storage device 1m-40 may include a plurality of memories.

[0275] The controller 1m-50 can control all operations of the BS. For example, the controller 1m-50 can send or receive signals through the baseband processor 1m-20 and the RF processor 1m-10 or through the backhaul communicator 1m-30. The controller 1m-50 can also write data to the storage device 1m-40 and read data from the storage device 1m-40. To this end, the controller 1m-50 may include at least one processor. In addition, according to an embodiment of the present disclosure, the controller 1m-50 may include a multi-connection processor 1m-52 that performs processing for operating in a multi-connection mode.

[0276] The methods according to the embodiments of the present disclosure described in the accompanying claims or the specification thereof can be implemented by hardware, software, or a combination of hardware and software.

[0277] When these methods are implemented in software, a computer-readable storage medium having at least one program (software module) stored therein may be provided. At least one program stored in the computer-readable storage medium is configured to be executed by at least one processor in an electronic device. The at least one program includes instructions that cause the electronic device to execute the method of the embodiment of the present disclosure described in the claim or its specification.

[0278] The program (software module or software) may be stored in RAM, non-volatile memory including flash memory, ROM, electrically erasable programmable ROM (EEPROM), magnetic disk storage devices, CD-ROM, DVD or other types of optical storage devices, and cassette tapes. Alternatively, the program may be stored in a memory configured as a combination of some or all of the devices. Multiple such memories may be included.

[0279] In addition, the program can be stored in an attachable storage device, which can be accessed through a communication network such as the Internet, an intranet, a LAN, a wide area network (WLAN), and a storage area network (SAN), or a communication network configured in combination thereof. Such a storage device can be connected to a device for performing a method according to an embodiment of the present disclosure via an external port. In addition, an independent storage device on a communication network can also be connected to a device for performing a method according to an embodiment of the present disclosure.

[0280] In a specific embodiment of the present disclosure, the components included in the present disclosure are expressed in singular or plural form, depending on the specific embodiment presented. However, for ease of description, singular or plural expression is selected to suit the presented situation, and the present disclosure is not limited to elements in singular or plural form, that is, an element expressed in plural form can be configured as a single element, or an element expressed in singular form can be configured as multiple elements.

[0281] In addition, although specific embodiments have been described in the detailed description of the present disclosure, various modifications may be made therein without departing from the scope of the present disclosure. Therefore, the scope of the present disclosure should not be limited to the described embodiments, but is defined by the attached claims and their equivalents. For those of ordinary skill in the art, other modifications based on the technical spirit of the present disclosure are achievable. If necessary, these embodiments may be combined with each other for operation. For example, parts of the methods presented in the present disclosure may be combined with each other to operate a BS and a UE. Although the embodiments are proposed based on 5G or NR systems, other modifications based on the technical spirit of the embodiments may be applicable to other systems, such as LTE, LTE-A, and LTE-A-Pro systems.

Claims

1. An operating method of a user equipment UE in a wireless communication system, the operating method comprising: receiving a radio resource control (RRC) message from a base station, wherein the RRC message includes logged minimization of drive tests (MDT) configuration information, wherein the logged MDT configuration information includes area configuration information; Based on the logged MDT configuration information, identifying a report type; In a case where the UE is camped on a cell in a normal camped state, a registered public land mobile network RPLMN is included in a public land mobile network PLMN identity list stored in the UE, and the cell is included in a logging area indicated in the area configuration information, determining, based on the logged MDT configuration information, whether a condition corresponding to an event type of the reporting type is satisfied; as well as If the condition is met, when the UE is in RRC_IDLE mode or RRC_INACTIVE mode within the logging area, performing logging of at least one measurement, Wherein, based on the PLMN identification information list and area configuration information included in the system information block type 1 SIB1, it is determined whether the cell is included in the recording area.

2. The operating method according to claim 1, in, The logged MDT configuration information further includes at least one of the report type, the event type, or a PLMN identifier list, and The area configuration information includes a new radio cell global identifier NCGI, and the NCGI includes a PLMN identity and a cell identity corresponding to the PLMN identity.

3. The operating method according to claim 1, further comprising: determining whether the PLMN identity included in the area configuration information is the same as the PLMN identity corresponding to the first entry of the PLMN identity list in the first entry of the PLMN identity information list included in the SIB1; and Determine whether the cell identifier included in the area configuration information belongs to the cell identifier corresponding to the first entry in the PLMN identifier information list included in the SIB1.

4. The operating method according to claim 1, in, The area configuration information includes a cell identifier and a tracking area code TAC.

5. A method for operating a base station in a wireless communication system, the method comprising: Sending a radio resource control (RRC) message including logged minimization of drive tests (MDT) configuration information to a user equipment (UE), wherein the logged MDT configuration information includes area configuration information; as well as receiving from the UE a message comprising a record of at least one measurement, Wherein, based on whether the logged MDT configuration information satisfies a condition corresponding to an event type of a reporting type, when the UE is in a logging area and in an RRC_IDLE mode or an RRC_INACTIVE mode, at least one measurement is logged, Wherein, in the case where the UE is camped on a cell in a normal camping state, a registered public land mobile network RPLMN is included in a public land mobile network PLMN identification list stored in the UE, and the cell is included in a recording area indicated in the area configuration information, determining whether the condition is satisfied, and Wherein, based on the PLMN identification information list and area configuration information included in the system information block type 1 SIB1, it is determined whether the cell is included in the recording area.

6. The operating method according to claim 5, in, The logged MDT configuration information further includes at least one of the report type, the event type, or a PLMN identifier list, and The area configuration information includes a new radio cell global identifier NCGI, and the NCGI includes a PLMN identity and a cell identity corresponding to the PLMN identity.

7. The operating method according to claim 5, wherein: When the PLMN identifier included in the area configuration information is the same as the PLMN identifier corresponding to the first entry of the PLMN identifier list in the first entry of the PLMN identifier information list included in the SIB1, and the cell identifier included in the area configuration information belongs to the cell identifier corresponding to the first entry of the PLMN identifier information list included in the SIB1, the cell is included in the recording area.

8. The operating method according to claim 5, in, The area configuration information includes a cell identifier and a tracking area code TAC.

9. A user equipment UE operating in a wireless communication system, the UE comprising: communicator; and at least one processor coupled to the communicator and configured to: receiving a radio resource control (RRC) message from a base station, wherein the RRC message includes logged minimization of drive tests (MDT) configuration information, wherein the logged MDT configuration information includes area configuration information, Based on the logged MDT configuration information, identifying a report type, determining, based on the logged MDT configuration information, whether a condition corresponding to the event type of the reporting type is satisfied, if the UE is camped on a cell in a normal camped state, a registered public land mobile network RPLMN is included in a public land mobile network PLMN identity list stored in the UE, and the cell is included in a logging area indicated in the area configuration information; and If the condition is met, when the UE is in the logging area and in the RRC_IDLE mode or the RRC_INACTIVE mode, performing logging of at least one measurement, Wherein, based on the PLMN identification information list and area configuration information included in the system information block type 1 SIB1, it is determined whether the cell is included in the recording area.

10. The UE according to claim 9, in, The logged MDT configuration information further includes at least one of the report type, the event type, or a PLMN identifier list, and The area configuration information includes a new radio cell global identifier NCGI, and the NCGI includes a PLMN identity and a cell identity corresponding to the PLMN identity.

11. The UE according to claim 9, wherein: The at least one processor is further configured to: determining whether the PLMN identity included in the area configuration information is the same as the PLMN identity corresponding to the first entry of the PLMN identity list in the first entry of the PLMN identity information list included in the SIB1; and Determine whether the cell identifier included in the area configuration information belongs to the cell identifier corresponding to the first entry in the PLMN identifier information list included in the SIB1.

12. The UE according to claim 9, in, The area configuration information includes a cell identifier and a tracking area code TAC.

Images