Method and apparatus for managing information about rrc connection in wireless communication system

Abstract

The terminal is configured to start a timer when the RRC connection setup / resume procedure is initiated, identify that the timer expires or receives an integrity check failure indication while the timer is running, determine whether at least one of a first condition or a second condition is satisfied, set a count on connection failure included in the information container to 0 when at least one of the first condition or the second condition is satisfied, and clear contents included in the information container except for the count on connection failure after determining whether at least one of the first condition or the second condition is satisfied.

Description

TECHNICAL FIELD

[0001] The disclosure relates to a method and apparatus for managing information about a radio resource control (RRC) connection in a wireless communication system. More particularly, the disclosure relates to a method and apparatus for collecting and reporting RRC connection configuration and recovery failure information. BACKGROUND

[0002] To meet the increasing demand for wireless data traffic due to the commercialization of fourth generation (4G) systems and an increase in multimedia services, improved fifth generation (5G) communication systems or pre-5G communication systems have been developed. This is one reason why 5G communication systems or pre-5G communication systems are also called beyond 4G network communication systems or post long term evolution (LTE) systems.

[0003] To improve data rates, 5G communication systems are being developed to implement in ultra-high frequency bands (millimeter wave (mmWave) bands), such as 60 gigahertz (GHz) bands. To reduce path loss of radio waves and increase a transmission distance of the radio waves in the ultra-high frequency bands, in 5G communication systems, technologies for beamforming, massive multiple input multiple output (MIMO), full dimensional MIMO (FD-MIMO), array antennas, analog beamforming, and large-scale antennas are being discussed.

[0004] In addition, to improve system network performance of 5G communication systems, various technologies, such as evolved small cells, advanced small cells, cloud radio access networks (cloud-RAN), ultra-dense networks, device-to-device communication (D2D), wireless backhaul, mobile networks, cooperative communication, coordinated multi-points (CoMP), and interference cancellation, have been developed. In addition, for 5G communication systems, advanced coding modulation (ACM) technologies, such as hybrid frequency shift keying (FSK) and quadrature amplitude modulation (QAM) (FQAM) and sliding window superposition coding (SWSC), and advanced access technologies, such as filter bank multi-carrier (FBMC), non-orthogonal multiple access (NOMA), and sparse code multiple access (SCMA), have been developed.

[0005] The internet has evolved from a human-based network of connections where humans create and consume information to the Internet of Things (IoT), in which distributed elements, such as objects, exchange information to process it. The Internet of Everything (IoE) technology is emerging, where IoT-related technologies are combined with technologies such as those that process big data by connecting to cloud servers. To realize IoT, various technological elements are needed, such as sensing technologies, wired / wireless communication and network infrastructure, service interface technologies, and security technologies. In recent years, technologies including sensor networks for connecting objects, machine-to-machine (M2M) communication, and machine-type communication (MTC) have been researched. In the IoT environment, intelligent Internet technology (IT) services can be provided to collect and analyze data from interconnected objects to create new value in human life. Through the integration and combination of existing information technology (IT) and various industries, IoT can be applied to a wide range of fields, such as smart homes, smart buildings, smart cities, smart cars / connected cars, smart grids, healthcare, smart appliances, and advanced medical services.

[0006] Various attempts are underway to apply 5G communication systems to IoT networks. For example, technologies such as sensor networks, M2M communication, and MTC are being implemented using 5G communication technologies such as beamforming, MIMO, and array antennas. The aforementioned application of cloud-RAN as a big data processing technology may be an example of the convergence of 5G communication and IoT technologies.

[0007] With the development of wireless communication systems and the aforementioned technologies enabling the provision of various services, there is a particular need for a method for collecting and reporting RRC connection configuration and recovery failure information.

[0008] The above information is presented as background information only to aid in understanding this disclosure. No determination or assertion is made regarding whether any of the above can be applied to this disclosure as prior art. Summary of the Invention

[0009] Technical solutions

[0010] A terminal for transmitting signals in a wireless communication system is provided. The terminal includes a transceiver and at least one processor configured to start a timer when a Radio Resource Control (RRC) connection establishment process or an RRC connection recovery process is initiated, identify when the timer expires or when an integrity check failure indication is received from a lower layer during timer operation, determine whether at least one of a first condition or a second condition is met, the first condition including a condition that the terminal has available connection failure information in an information container and the registered Public Land Mobile Network (PLMN) does not correspond to a PLMN identifier included in the information container, and the second condition including a condition that a first cell identifier of the current cell is not equal to a second cell identifier stored in measurement result information about the cell in which the connection failure occurred, and in response to determining that at least one of the first or second conditions is met, set a count of connection failures included in the information container to 0, and after determining that at least one of the first or second conditions is met, clear all content included in the information container except for the count of connection failures. Attached Figure Description

[0011] The above and other aspects, features, and advantages of specific embodiments of the present disclosure will become more apparent from the following description taken in conjunction with the accompanying drawings, in which:

[0012] Figure 1A This is a diagram illustrating the structure of a Long Term Evolution (LTE) system according to an embodiment of the present disclosure;

[0013] Figure 1B This is a diagram illustrating the radio protocol architecture of an LTE system according to an embodiment of the present disclosure;

[0014] Figure 1C This is a diagram illustrating the structure of a next-generation mobile communication system according to an embodiment of the present disclosure;

[0015] Figure 1D This is a diagram illustrating the radio protocol architecture of a next-generation mobile communication system according to embodiments of the present disclosure;

[0016] Figure 1E This is a diagram illustrating a method for collecting and reporting cell measurement information according to embodiments of the present disclosure;

[0017] Figure 1F This is a flowchart illustrating the process by which a terminal (e.g., a user equipment (UE)) in an NR system according to an embodiment of the present disclosure collects Radio Resource Control (RRC) connection establishment failure information and reports it to a new radio (NR) base station;

[0018] Figure 1GThis is a flowchart illustrating the process by which a terminal (e.g., a UE) in an NR system according to an embodiment of the present disclosure collects RRC connection recovery failure information and reports it to an NR base station;

[0019] Figure 1H This is a flowchart illustrating the process by which a terminal (e.g., UE) in an NR system according to an embodiment of the present disclosure collects RRC connection establishment failure information and reports it to an NR base station;

[0020] Figure 1I This is a flowchart illustrating the process by which a terminal (e.g., a UE) in an NR system according to an embodiment of the present disclosure collects RRC connection recovery failure information and reports it to an NR base station;

[0021] Figure 1J This is a flowchart illustrating the terminal operation in an NR system according to embodiments of the present disclosure, in which a terminal (e.g., UE) collects RRC connection establishment failure information and reports it to an NR base station.

[0022] Figure 1K This is a flowchart illustrating the terminal operation in an NR system according to embodiments of the present disclosure, in which a terminal (e.g., UE) collects RRC connection establishment failure information and reports it to an NR base station.

[0023] Figure 1L This is a block diagram illustrating the internal structure of a terminal (e.g., a UE) according to an embodiment of the present disclosure; and

[0024] Figure 1M This is a block diagram illustrating the architecture of an NR base station according to an embodiment of the present disclosure.

[0025] In all the accompanying drawings, it should be noted that the same reference numerals are used to describe the same or similar elements, features, and structures. Detailed Implementation

[0026] The aspects of this disclosure at least address the aforementioned problems and / or disadvantages, and at least provide the following advantages. Therefore, one aspect of this disclosure is to provide an apparatus and method for effectively collecting and reporting Radio Resource Control (RRC) connection configuration and recovery failure information in a wireless communication system.

[0027] Additional aspects will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practicing the embodiments presented in this disclosure.

[0028] According to one aspect of this disclosure, a terminal for transmitting signals in a wireless communication system is provided. The terminal includes a transceiver and at least one processor configured to start a timer when an RRC connection establishment process or an RRC connection recovery process is initiated, identify when the timer expires or when an integrity check failure indication is received from a lower layer during timer operation, determine whether at least one of a first condition or a second condition is met, the first condition including a condition that the terminal has available connection failure information in an information container and the registered Public Land Mobile Network (PLMN) does not correspond to a PLMN identifier included in the information container, and the second condition including a condition that a first cell identifier of the current cell is not equal to a second cell identifier stored in measurement result information about the cell in which the connection failure occurred, and in response to determining that at least one of the first or second conditions is met, setting a count of connection failures included in the information container to 0, and after determining whether at least one of the first or second conditions is met, clearing all content included in the information container except for the count of connection failures.

[0029] The information container may include connection failure report information and PLMN identifier, and the connection failure report information may include a count of connection failures and measurement results information about the cell in which the connection failure occurred.

[0030] In response to a failure of the RRC connection establishment or recovery process, the PLMN identifier and measurement information about the cell where the connection failure occurred can be stored in an information container.

[0031] Measurement information about the cell where the connection failure occurred may include at least one of the following: global cell identifier, tracking area code, reference signal received power (RSRP), or reference signal received quality (RSRQ).

[0032] Connection failure information may include at least one of connection establishment failure information or connection recovery failure information.

[0033] The at least one processor can also be configured to send an RRC establishment request message to the base station (BS) in idle mode or an RRC recovery request message in inactive mode, receive an RRC establishment message from the BS, enter a connection mode, identify that the terminal has available connection failure information in the information container and that the registered PLMN corresponds to the PLMN identifier included in the information container, send an RRC establishment completion message to the BS including a first indicator indicating that the terminal has available connection failure information, receive a terminal information request message from the BS including a second indicator reporting connection failure information, and, if the second indicator is set to true, send a terminal information response message to the BS including connection failure reporting information, the connection failure reporting information including a count of connection failures.

[0034] The at least one processor can also be configured to discard connection failure report information included in the information container after the confirmation terminal information response message has been sent.

[0035] The at least one processor may also be configured to select a PLMN from one or more PLMNs included in the PLMN identifier list in the system information, and store a second PLMN identifier corresponding to the selected PLMN in the information container.

[0036] The at least one processor may also be configured to determine whether the second PLMN identifier of the registered PLMN is included in the information container, and if the second PLMN identifier of the registered PLMN is not included in the information container, to select a PLMN from one or more PLMNs included in the PLMN identifier list in the system information, and to store the second PLMN identifier corresponding to the selected PLMN in the information container.

[0037] The at least one processor can also be configured to store a second PLMN identifier corresponding to the registered PLMN in an information container in an inactive mode, without PLMN selection.

[0038] The information container can include VarConnEstFailReport.

[0039] According to another aspect of this disclosure, a method for transmitting signals in a wireless communication system, performed by a terminal, is provided. The method includes: starting a timer when a Radio Resource Control (RRC) connection establishment procedure or an RRC connection recovery procedure is initiated; identifying when the timer expires or when the timer is running; receiving an integrity check failure indication from a lower layer; determining whether at least one of a first condition or a second condition is met; the first condition includes a condition that the terminal has available connection failure information in an information container and the registered Public Land Mobile Network (PLMN) does not correspond to a PLMN identifier included in the information container; and the second condition includes a condition that a first cell identifier of the current cell is not equal to a second cell identifier stored in measurement result information about the cell in which the connection failure occurred; in response to determining that at least one of the first or second conditions is met, setting a count of connection failures included in the information container to 0; and after determining that at least one of the first or second conditions is met, clearing all content included in the information container except for the count of connection failures.

[0040] The information container may include connection failure report information and PLMN identifier, and the connection failure report information may include a count of connection failures and measurement results information about the cell in which the connection failure occurred.

[0041] In response to a failure of the RRC connection establishment or recovery process, the PLMN identifier and measurement information about the cell where the connection failure occurred can be stored in an information container.

[0042] Measurement information about the cell where the connection failure occurred may include at least one of the following: global cell identifier, tracking area code, reference signal received power (RSRP), or reference signal received quality (RSRQ).

[0043] Connection failure information may include at least one of connection establishment failure information or connection recovery failure information.

[0044] The method may further include sending an RRC establishment request message to a base station (BS) in idle mode or an RRC recovery request message in inactive mode, receiving an RRC establishment message from the BS, entering a connection mode, identifying that the terminal has available connection failure information in the information container and that the registered PLMN corresponds to the PLMN identifier included in the information container, sending an RRC establishment completion message to the BS including a first indicator indicating that the terminal has available connection failure information, receiving a terminal information request message from the BS including a second indicator reporting connection failure information, and, if the second indicator is set to true, sending a terminal information response message to the BS including connection failure reporting information, the connection failure reporting information including a count of connection failures.

[0045] The method may also include discarding connection failure report information included in the information container after the confirmation terminal information response message has been sent.

[0046] The method may further include selecting a PLMN from one or more PLMNs included in the PLMN identifier list in the system information, and storing a second PLMN identifier corresponding to the selected PLMN in an information container.

[0047] The method may further include determining whether the second PLMN identifier of the registered PLMN is included in the information container, and if the second PLMN identifier of the registered PLMN is not included in the information container, selecting a PLMN from one or more PLMNs included in the PLMN identifier list in the system information, and storing the second PLMN identifier corresponding to the selected PLMN in the information container.

[0048] The method may also include storing a second PLMN identifier corresponding to the registered PLMN (RPLMN) in an information container in the inactive mode, when no PLMN is selected.

[0049] The information container can include VarConnEstFailReport.

[0050] Other aspects, advantages, and distinctive features of this disclosure will become apparent to those skilled in the art from the following detailed description of various embodiments disclosed in conjunction with the accompanying drawings.

[0051] Inventive Method

[0052] The following description, provided with reference to the accompanying drawings, is intended to aid in a full understanding of the various embodiments of this disclosure as defined by the claims and their equivalents. It includes various specific details to aid understanding, but these are to be considered exemplary only. Therefore, those skilled in the art will recognize that various changes and modifications can be made to the various embodiments described herein without departing from the scope and spirit of this disclosure. Furthermore, for clarity and brevity, descriptions of well-known functions and constructions may be omitted.

[0053] The terms and words used in the following description and claims are not limited to their documentary meaning, but are used solely by the inventors to enable a clear and consistent understanding of this disclosure. Therefore, it will be apparent to those skilled in the art that the following description of various embodiments of this disclosure is provided for illustrative purposes only and is not intended to limit the disclosure as defined by the appended claims and their equivalents.

[0054] It should be understood that the singular forms “a,” “an,” and “the” include plural indicators unless the context clearly specifies otherwise. Thus, for example, referring to “the surface of a component” includes referring to one or more such surfaces.

[0055] Throughout the disclosure, the expression "at least one of a, b, or c" means only a, only b, only c, both a and b, both a and c, both b and c, all of a, b, and c, or variations thereof.

[0056] Examples of terminals may include user equipment (UE), mobile station (MS), cellular phone, smartphone, computer, multimedia system capable of performing communication functions, etc.

[0057] In this disclosure, the controller may also be referred to as a processor.

[0058] Throughout the specification, a layer (or layer device) may also be referred to as an entity.

[0059] The advantages and features of this disclosure, as well as methods of implementing them, will become clear from the accompanying drawings illustrating embodiments. However, this disclosure may be implemented in many different forms and should not be construed as limited to the embodiments set forth below. Rather, embodiments are provided to make this disclosure thorough and complete, and to fully convey the concept of this disclosure to those skilled in the art to which this disclosure pertains, and this disclosure will be defined only by the appended claims. Throughout this specification, the same reference numerals denote the same elements.

[0060] It should be understood that the boxes and combinations of flowcharts in a process flowchart can be executed by computer program instructions. These computer program instructions can be loaded into the processor of a general-purpose computer, special-purpose computer, or other programmable data processing apparatus, such that those instructions, executed by the processor of the computer or other programmable data processing apparatus, create means for performing the functions described in the flowchart boxes(s). These computer program instructions can also be stored in a computer-executable or computer-readable storage medium, which can instruct the computer or other programmable data processing apparatus to perform functions in a particular manner, such that the instructions stored in the computer-executable or computer-readable storage medium can also produce a manufacturing item containing instruction means for performing the functions described in the flowchart boxes(s). The computer program instructions can also be mounted on a computer or other programmable data processing apparatus, thereby enabling a series of operations to be performed on the computer or other programmable data processing apparatus to create a computer-executable process. Therefore, the instructions can also potentially operate the computer or other programmable data processing apparatus to provide operations for performing the functions described in the flowchart boxes(s).

[0061] Furthermore, each box may represent a code module, segment, or section comprising one or more executable instructions for performing a specific logical function(s). It should also be noted that in some alternative implementations, the functions mentioned in the boxes may not appear in a specific order. For example, two boxes shown consecutively may be executed substantially simultaneously, or these boxes may sometimes be executed in reverse order according to their corresponding functions.

[0062] In this context, the term "unit" as used in the embodiments described herein refers to a software element or hardware element that performs a specific function, such as a field-programmable gate array (FPGA) or application-specific integrated circuit (ASIC). However, the terms "part," "module," or "unit" are not limited to software or hardware. A "part," "module," or "unit" may be configured in an addressable storage medium or may be configured to run on at least one processor. Thus, by way of example, a "part," "module," or "unit" includes elements such as software elements, object-oriented software elements, class elements, and task elements; processes; functions; attributes; procedures; subroutines; program code segments; drivers; firmware; microcode; circuits; data; databases; data structures; tables; arrays; and variables. Functionality provided in elements and "parts," "modules," or "units" may be combined into a smaller number of elements and "parts," "modules," and "units," or subdivided into additional elements and "parts," "modules," or "units." Furthermore, elements and "parts," "modules," or "units" may be configured to run on one or more central processing units (CPUs) in a device or secure multimedia card. In embodiments of this disclosure, a “part,” “module,” or “unit” may include one or more processors.

[0063] In the following description of this disclosure, descriptions of known functionalities or configurations will be omitted where it is determined that detailed descriptions of such functionalities or configurations may unnecessarily obscure the subject matter of this disclosure.

[0064] Furthermore, the terms used herein to identify access nodes, network entities, messages, interfaces between network entities, and various types of identification information are illustrative for ease of description. Therefore, this disclosure is not limited to the terms used herein, and different terms may be used to refer to objects that have the same technical meaning.

[0065] For ease of description, this document uses the terms and names defined in the 3GPP LTE standard. However, this disclosure is not limited to such terms and names and can be applied equivalently to systems conforming to other standards. In this disclosure, for ease of description, Evolved Node B (eNB) will be used interchangeably with Next Generation Node B (gNB). For example, a base station described as an eNB may represent a gNB.

[0066] Future communication systems following LTE, namely 5G communication systems, must be able to freely reflect the diverse requirements of users and service providers. Therefore, they must support services that simultaneously meet various needs. Services considered for 5G communication systems include enhanced mobile broadband (eMBB), massive machine-type communications (mMTC), and ultra-reliable low-latency communications (URLLC).

[0067] According to embodiments of this disclosure, eMBB is designed to provide data rates higher than those supported by LTE, LTE-advanced (LTE-A), or LTE-Pro. For example, in a 5G communication system, for a single base station, eMBB must be able to provide a peak data rate of 20 gigabits per second (Gbps) in the downlink and a peak data rate of 10 Gbps in the uplink. Furthermore, the 5G communication system must provide peak data rates while also providing increased user-aware data rates for the UE. To meet these requirements, various transmission and reception technologies need to be improved, including improved multiple-input multiple-output (MIMO) transmission technologies. Moreover, signals are transmitted using up to 20 MHz of transmission bandwidth in the 2 GHz band used in current LTE systems, but 5G communication systems use bandwidths wider than 20 MHz in the 3 GHz to 6 GHz or greater bands to meet the data rates required in 5G communication systems.

[0068] Meanwhile, mMTC is being considered to support application services such as the Internet of Things (IoT) in 5G communication systems. To effectively deliver IoT, mMTC needs to support a large number of UEs in a cell, improve UE coverage, improve battery life, and reduce UE costs. Because IoT connects to various sensors and devices to provide communication functions, it must be able to support a large number of UEs in a cell (e.g., 1,000,000 UEs / km). 2 Furthermore, due to the nature of the service, mMTC-enabled UEs may be located in shadow areas not covered by cell coverage, such as the basement of a building. Therefore, they may require wider coverage than other services offered by 5G communication systems. mMTC-enabled UEs must be configured as inexpensive UEs, and their batteries are difficult to replace frequently. Therefore, they may require very long battery life, such as 10 to 15 years.

[0069] Finally, URLLC stands for Cellular Wireless Communication Service for a specific purpose (mission-critical). URLLC can be used in services such as remote control of robots or machines, industrial automation, unmanned aerial vehicles, telemedicine, and emergency alerts. Therefore, communication provided by URLLC must offer very low latency and very high reliability. For example, services supporting URLLC may need to meet an air interface latency of less than 0.5 milliseconds, while potentially requiring a latency equal to or less than 10 milliseconds. -5 The packet error rate. Therefore, for services supporting URLLC, 5G systems must provide smaller transmission time intervals (TTIs) than other services, while also requiring the allocation of wide resources in the frequency band to ensure the reliability of the communication link.

[0070] The three services considered in 5G communication systems—eMBB, URLLC, and mMTC—can be multiplexed and transmitted within a single system. In this case, different transmission and reception technologies and parameters can be used between services to meet their varying requirements. However, mMTC, URLLC, and eMBB are merely examples of different service types, and the service types to which this disclosure applies are not limited to the foregoing examples.

[0071] Furthermore, although embodiments of this disclosure will be described below using LTE, LTE-A, LTE Pro, or 5G (or New Radio (NR) as a next-generation mobile communication) as examples, embodiments of this disclosure can also be applied to other communication systems with similar technical backgrounds or channel configurations. Moreover, based on the judgment of those skilled in the art, embodiments of this disclosure can also be applied to other communication systems with some modifications without departing from the scope of this disclosure in essence.

[0072] In the following description, embodiments of the present disclosure will be described with reference to the accompanying drawings.

[0073] Figure 1A This is a diagram illustrating the structure of an LTE system according to an embodiment of the present disclosure.

[0074] refer to Figure 1A The radio access network of an LTE system may include evolved Node Bs (hereinafter also referred to as eNBs, Node Bs, or base stations) 1a-05, 1a-10, 1a-15, and 1a-20, a Mobility Management Entity (MME) 1a-25, and a Service Gateway (S-GW) 1a-30. A UE (or terminal) 1a-35 can access external networks through eNBs 1a-05 to 1a-20 and S-GW 1a-30.

[0075] refer to Figure 1AeNBs 1a-05 to 1a-20 can correspond to existing Node Bs in a Universal Mobile Telecommunications Service (UMTS) system. eNBs 1a-05, 1a-10, 1a-15, or 1a-20 can connect to UE 1a-35 on a radio channel and can perform more complex functions compared to existing Node Bs. In LTE systems, all user services, including real-time services such as Voice over Internet Protocol (VoIP) based on the Internet Protocol, can be provided on a shared channel. Therefore, an entity is needed to collect state information such as the UE's buffer state, available transmit power state, and channel state, and to perform scheduling; this operation can be performed by eNBs 1a-05 to 1a-20. A single eNB 1a-05, 1a-10, 1a-15, or 1a-20 can typically control multiple cells. For example, an LTE system can achieve a data rate of 100 Mbps using radio access technologies such as Orthogonal Frequency Division Multiplexing (OFDM) within a 20 MHz bandwidth. Furthermore, an adaptive modulation and coding (AMC) scheme can be applied to determine the modulation scheme and channel coding rate based on the UE's channel state. The S-GW 1a-30 is the entity that provides the data bearer and can configure or release the data bearer under the control of the MME 1a-25. The MME 1a-25 is the entity that performs various control functions and UE mobility management, and is connected to multiple eNBs.

[0076] Figure 1B This is a diagram illustrating the radio protocol architecture of an LTE system according to an embodiment of the present disclosure.

[0077] refer to Figure 1B The radio protocol architecture of the LTE system includes Packet Data Convergence Protocol (PDCP) layers 1b-05 and 1b-40 for the UE and eNB, Radio Link Control (RLC) layers 1b-10 and 1b-35, and Media Access Control (MAC) layers 1b-15 and 1b-30. PDCP layer 1b-05 or 1b-40 can perform operations such as IP header compression / reconstruction. The main functions of PDCP layer 1b-05 or 1b-40 can be summarized as follows:

[0078] - Header compression and decompression: Robust header compression only (ROHC)

[0079] -Transmission of user data

[0080] - For RLC Acknowledgment Mode (AM), the sequential delivery of upper-layer Packet Data Units (PDUs) during PDCP reconstruction.

[0081] - In Dual Connectivity (DC) for split bearers (RLC AM only): PDCP PDU routing for transmission and PDCP PDU reordering for reception.

[0082] - For RLC AM, duplicate detection of lower-layer service data units (SDUs) during PDCP reconstruction.

[0083] - For RLC AM, retransmission of PDCP SDU during handover, and retransmission of PDCP PDU during PDCP data recovery process in DC for split bearers.

[0084] - Encryption and decryption

[0085] - Timer-based SDU dropping in the uplink

[0086] RLC layer 1b-10 or 1b-35 can perform automatic repeat request (ARQ) operations, etc., by reconfiguring PDCP PDUs to an appropriate size. The main functions of RLC layer 1b-10 or 1b-35 can be summarized as follows:

[0087] -Transmission of upper-layer PDUs

[0088] - Error correction via ARQ (AM data transmission only)

[0089] - Concatenation, segmentation, and reassembly of RLC SDUs (only for Unacknowledged Mode (UM) and AM data transmission)

[0090] - Resegmentation of RLC data PDUs (AM data transmission only)

[0091] - Reordering of RLC data PDUs (only for UM and AM data transfers)

[0092] - Duplicate detection (only for UM and AM data transmission)

[0093] - Protocol error detection (AM data transmission only)

[0094] -RLC SDU discard (only for UM and AM data transfers)

[0095] -RLC Reconstruction

[0096] MAC layer 1b-15 or 1b-30 connects to multiple RLC layers configured for a UE, and can multiplex RLC PDUs into MAC PDUs and demultiplex RLC PDUs from MAC PDUs. The main functions of MAC layer 1b-15 or 1b-30 can be summarized as follows:

[0097] Mapping between logical channels and transport channels

[0098] - Multiplexing MAC SDUs belonging to one or different logical channels into a transport block (TB) delivered to the physical layer on the transport channel / Demultiplexing MAC SDUs belonging to one or different logical channels from a transport block (TB) delivered to the physical layer on the transport channel.

[0099] - Scheduling Information Report

[0100] - Error correction via HARQ

[0101] Priority processing between logical channels of a UE

[0102] - Prioritization among UEs is performed through dynamic scheduling.

[0103] - Multimedia Broadcasting and Multimedia Services (MBMS) Service Identifier

[0104] -Transmission format selection

[0105] -filling

[0106] The physical (PHY) layer 1b-20 or 1b-25 can perform the following operations: channel coding and modulation of upper-layer data, converting the channel-coded and modulated upper-layer data into OFDM symbols and transmitting the OFDM symbols via a radio channel, or demodulating OFDM symbols received via a radio channel, channel decoding of the demodulated OFDM symbols, and transmitting the decoded OFDM symbols to the upper layer.

[0107] Figure 1C This is a diagram illustrating the structure of a next-generation mobile communication system according to an embodiment of the present disclosure.

[0108] refer to Figure 1C The radio access network for next-generation mobile communication systems (hereinafter referred to as NR or 5G) may include NR node B1c-10 (hereinafter referred to as NR gNB or NR base station) and NR core network (CN) 1c-05. NR UE 1c-15 (or terminal) can access external networks through NR gNB 1c-10 and NR CN1c-05.

[0109] refer to Figure 1CThe NR gNB 1c-10 corresponds to the eNB in ​​existing LTE systems. The NR gNB 1c-10 connects to the NR UE 1c-15 on the radio channel and can provide better service than existing NodeBs. In next-generation mobile communication systems, because all user services are served through a shared channel, an entity is needed to collect state information such as the UE's buffer state, available transmit power state, and channel state, and to perform scheduling; this operation can be performed by the NR gNB 1c-10. A single NR gNB 1c-10 can typically control multiple cells. To achieve ultra-high data transmission compared to current LTE systems, NR or 5G systems can use the existing maximum bandwidth or greater, using OFDM as the radio access technology, or combining OFDM with beamforming technology. Furthermore, AMC schemes can be applied to determine the modulation scheme and channel coding rate based on the UE's channel state. The NR CN 1c-05 performs functions such as mobility support, bearer configuration, and Quality of Service (QoS) configuration. The NR CN 1c-05 is the entity that performs various control functions and UE mobility management, and connects to multiple gNBs. Furthermore, the next-generation mobile communication system is interoperable with existing LTE systems, and the NR CN 1c-05 can connect to the MME 1c-25 via a network interface. The MME 1c-25 can connect to the eNB 1c-30, which serves as an existing base station.

[0110] Figure 1D This is a diagram illustrating the radio protocol architecture of a next-generation mobile communication system according to an embodiment of the present disclosure.

[0111] Figure 1D This is a diagram illustrating a radio protocol applicable to a next-generation mobile communication system according to the present disclosure.

[0112] refer to Figure 1D The radio protocol architecture of the next-generation mobile communication system may include NR Service Data Adaptation Protocol (SDAP) layers 1d-01 and 1d-45, NR PDCP layers 1d-05 and 1d-40, NR RLC layers 1d-10 and 1d-35, and NR MAC layers 1d-15 and 1d-30.

[0113] The main functions of NR SDAP layer 1d-01 or 1d-45 may include some of the following functions:

[0114] -Transmission of user plane data

[0115] - Mapping between QoS flows and DRBs for both downlink (DL) and uplink (UL)

[0116] - Mark QoS flow IDs in both DL and UL groups

[0117] - UL SDAP PDU reflection QoS flow to DRB mapping

[0118] Regarding the SDAP layer, the UE can be configured to use either the SDAP layer header or SDAP layer functionality via RRC messages for each PDCP layer, each bearer, or each logical channel. When the SDAP header is configured, the 1-bit Non-Access Stratum (NAS) reflected QoS configuration indicator and the 1-bit Access Stratum (AS) reflected QoS configuration indicator in the SDAP header can instruct the UE to update or reconfigure the mapping information between QoS flows and data bearers for both the UL and DL. The SDAP header may include a QoS flow ID indicating QoS. QoS information can be used as data processing priority information, scheduling information, etc., to support smooth service.

[0119] The main functions of NR PDCP layer 1d-05 or 1d-40 may include some of the following functions:

[0120] -Header compression and decompression: ROHC only

[0121] -Transmission of user data

[0122] - Sequential delivery of upper-layer PDUs

[0123] -Disordered delivery of upper-layer PDUs

[0124] - Reordering of received PDCP PDUs

[0125] -Duplicate detection of lower-level SDUs

[0126] -PDCP SDU retransmission

[0127] - Encryption and decryption

[0128] - Timer-based SDU dropping in the uplink

[0129] The reordering of NR PDCP layers 1d-05 and 1d-40 refers to the function of reordering PDCP PDUs received from the lower layer in order based on the PDCP sequence number (SN), and may include the function of delivering data to the upper layer in the reordered order or delivering data to the upper layer immediately regardless of the order, the function of recording lost PDCP PDUs by reordering PDCP PDUs, the function of reporting the status of lost PDCP PDUs to the sender, and the function of requesting retransmission of lost PDCP PDUs.

[0130] The primary functionality of NR RLC layers 1d-10 or 1d-35 may include at least some of the following functions:

[0131] -Transmission of upper-layer PDUs

[0132] - Sequential delivery of upper-layer PDUs

[0133] -Disordered delivery of upper-layer PDUs

[0134] - Error correction via ARQ

[0135] - Assembly, segmentation and reassembly of RLC SDUs

[0136] - Resegmentation of RLC data PDUs

[0137] - Reordering of RLC data PDUs

[0138] -Duplicate detection

[0139] -Protocol error detection

[0140] -RLC SDU discard

[0141] -RLC Reconstruction

[0142] The sequential delivery of NR RLC layers 1d-10 or 1d-35 may include the function of sequentially delivering RLC SDUs received from lower layers to upper layers. Furthermore, the sequential delivery of NR RLC layers 1d-10 or 1d-35 may include the function of reassembling and delivering RLC SDUs when a single RLC SDU is segmented into multiple RLC SDUs and received, as well as the function of reordering received RLC PDUs based on the RLC SN or PDCP SN. Additionally, the sequential delivery of NR RLC layers 1d-10 or 1d-35 may include the function of recording lost RLC PDUs by reordering RLC PDUs, and the function of reporting the status of lost RLC PDUs to the transmitting side. The sequential delivery of NR RLC layers 1d-10 or 1d-35 may include the function of requesting retransmission of lost RLC PDUs, and the function of only sequentially delivering RLC SDUs preceding the lost RLC SDU to the upper layer when a lost RLC SDU exists. Alternatively, the sequential delivery of NR RLC layers 1d-10 or 1d-35 may include the function of sequentially delivering all RLC SDUs received before the start of a specific timer to the upper layer when that timer expires, regardless of any lost RLC SDUs, or the function of sequentially delivering all currently received RLC SDUs to the upper layer when that timer expires, regardless of any lost RLC SDUs. NR RLC layers 1d-10 or 1d-35 may process RLC PDUs in the order they are received, regardless of the sequence number order (out-of-order delivery), and deliver them to NR PDCP layers 1d-05 or 1d-40. When a fragment is received, NR RLC layers 1d-10 or 1d-35 may receive fragments to be received later or stored in a buffer, reassemble the fragments into a complete RLC PDU, process the complete RLC PDU, and deliver it to NR PDCP layers 1d-05 or 1d-40. NR RLC layer 1d-10 or 1d-35 may not have splicing functionality, and the splicing functionality may be performed by NR MAC layer 1d-15 or 1d-30, or replaced by the multiplexing functionality of NR MAC layer 1d-15 or 1d-30.

[0143] Out-of-order delivery of NR RLC layer 1d-10 or 1d-35 refers to the function of immediately and out of order delivering RLC SDUs received from the lower layer to the upper layer. It may include the function of reassembling and delivering RLC SDUs when a single RLC SDU is segmented into multiple RLC SDUs and received, as well as the function of storing the RLC SN or PDCP SN of the received RLC PDUs and recording lost RLC PDUs by arranging the received RLC PDUs in order.

[0144] NR MAC layer 1d-15 or 1d-30 can be connected to multiple NR RLC layers 1d-10 or 1d-35 configured for a UE, and the main functions of NR MAC layer 1d-15 or 1d-30 may include at least some of the following functions:

[0145] Mapping between logical channels and transport channels

[0146] - MAC SDU multiplexing / demultiplexing

[0147] - Scheduling Information Report

[0148] - Error correction via HARQ

[0149] Priority processing is performed between logical channels of a UE.

[0150] - Prioritization among UEs is performed through dynamic scheduling.

[0151] -MBMS service identifier

[0152] -Transmission format selection

[0153] -filling

[0154] The NR PHY layer 1d-20 or 1d-25 can perform the following operations: channel coding and modulation of upper-layer data, converting the channel-coded and modulated upper-layer data into OFDM symbols and transmitting the OFDM symbols via a radio channel, or demodulating the OFDM symbols received on the radio channel, channel decoding the demodulated OFDM symbols, and transmitting the decoded OFDM symbols to the upper layer.

[0155] Figure 1E This is a diagram illustrating a method for collecting and reporting cell measurement information according to an embodiment of the present disclosure.

[0156] refer to Figure 1E When a network is established or optimized, mobile communication service providers (hereinafter referred to as operators) typically measure the signal strength in the intended service area and deploy or reposition gNBs in the service area based on the measured signal strength. Operators load signal measurement equipment into Ie-30 vehicles and collect cell measurement information in the service area, a process that requires significant time and cost. This process of collecting cell measurement information is typically performed using Ie-30 vehicles and is therefore referred to as drive testing.

[0157] UE 1e-25 is equipped with the ability to measure the signal of gNB 1e-15 to support operations such as cell reselection, handover, or adding a serving cell during movement between cells. Therefore, a UE within the serving area can be used instead of drive testing, a process known as Minimized Drive Testing (MDT). Operators can configure MDT operations for specific UEs through various network components, and UEs in RRC Connected, RRC Idle, or RRC Inactive modes can collect and store signal strength information from the serving cell and neighboring cells. Furthermore, UEs can store various information fragments, such as location information, time information, and signal quality information. The information fragments that a UE can store are not limited to the examples mentioned above. When a UE is in RRC Connected mode, the stored information can be reported to the network, and the stored information can be delivered to a specific server.

[0158] MDT operations can be broadly divided into immediate MDT operations and recorded MDT operations.

[0159] In an immediate MDT operation, the UE immediately reports the collected information to the network. The UE must report the collected information to the network immediately; only UEs in RRC connection mode can perform this immediate operation. Typically, Radio Resource Management (RRM) measurement procedures used to support operations such as serving cell handover and addition are reused, and location information, time information, etc., can be additionally reported to the network.

[0160] In a recorded MDT operation, the UE stores the collected information without immediately reporting it to the network. The UE reports the stored information after switching to RRC connected mode. Typically, UEs in RRC idle mode or RRC inactive mode, where it is impossible to immediately report collected information to the network, can perform recorded MDT operations. In this specification, UEs in RRC inactive mode, introduced in next-generation mobile communication systems, can perform recorded MDT operations. When a particular UE is in RRC connected mode, the network can provide the UE with configuration information for performing recorded MDT operations, and the UE can switch to RRC idle mode or RRC inactive mode, then collect and store the configuration information.

[0161] Table 1 below summarizes the MDT modes (immediate MDT and recorded MDT) that the UE can execute based on the UE's RRC status.

[0162] Table 1

[0163] RRC state Immediate MDT RRC CONNECTED Logged MDT RRC IDLE, RRC INACTIVE

[0164] Figure 1FThis is a flowchart illustrating the process by which a UE 1f-01 in an NR system according to an embodiment of the present disclosure collects Radio Resource Control (RRC) connection establishment failure information and reports it to an NR gNB 1f-02. (See also...) Figure 1F In operation 1f-03, UE 1f-01 can establish an RRC connection with NR gNB 1f-02 and is therefore in RRC connection mode (RRC_CONNECTED).

[0165] In operation 1f-04, NR gNB 1f-02 can send an RRCRelease message to UE 1f-01 that does not include suspend configuration information (suspendConfig).

[0166] In Operation 1f-05, a UE 1f-01 that receives an RRCLease message that does not include suspend configuration information (suspendConfig) can switch to RRC idle mode (RRC_IDLE).

[0167] In 1f-10, UE 1f-01 in RRC idle mode can perform a Public Land Mobile Network (PLMN) selection procedure. The Access Stratum (AS) layer of UE 1f-01 can report at least one available PLMN to the Non-Access Stratum (NAS) layer either upon request from the NAS layer or spontaneously (in the UE, the AS will report available PLMNs to the NAS upon request from the NAS layer or spontaneously). Specifically, UE 1f-01 can scan all RF channels in the NR band according to its ability to find available PLMNs (the UE will scan all RF channels in the NR band according to its ability to find available PLMNs). For each carrier, UE 1f-01 can find the cell with the strongest signal strength and read system information from that cell, and this is to find at least one PLMN to which that cell belongs (on each carrier, the UE will search for the strongest cell and read its system information to determine which of one or more PLMNs the cell belongs to). When UE 1f-01 is able to read at least one PLMN identifier in the cell with the strongest signal strength, UE 1f-01 can report each found PLMN to the NAS layer as a high-quality PLMN, provided that the following high-quality conditions are met (if the UE is able to read one or more PLMN identifiers in the strongest cell, each found PLMN will be reported to the NAS as a high-quality PLMN (but without RSRP value), provided that the following high-quality criteria are met).

[0168] - High-quality conditions: For NR cells, the measured reference signal received power (RSRP) value is greater than or equal to -110dBm (For NR cells, the measured RSRP value should be greater than or equal to -110dBm).

[0169] When a found PLMN does not meet the above high-quality conditions, but UE 1f-01 can read the PLMN identifier, UE 1f-01 can report the RSRP measurement value and the PLMN identifier to the NAS layer (PLMNs that do not meet the high-quality criteria but whose PLMN identifiers the UE can read are reported to the NAS along with their corresponding RSRP values). Each measurement value reported by UE 1f-01 to the NAS layer can be the value of each PLMN found in each cell (the quality measurement reported by the UE to the NAS should be the same for each PLMN found in a cell).

[0170] In response to a request from the NAS layer, the PLMN selection process may not be performed (the search for the PLMN can be stopped upon request from the NAS). UE 1f-01 can optimize the PLMN selection process by using stored information (e.g., information about frequency and cell parameters that may optionally be obtained from previously received measurement control information elements).

[0171] In operation 1f-15, when UE 1f-01 in RRC idle mode selects a PLMN, UE 1f-01 can perform a cell selection procedure to select a suitable cell for the PLMN so that it can camp on that suitable cell (once the UE has selected a PLMN, the cell selection procedure will be performed so that a suitable cell for the PLMN can be selected to camp on).

[0172] In Operation 1f-20, UE 1f-01 in RRC idle mode can perform a cell reselection process to find a more suitable cell.

[0173] In Operation 1f-25, UE 1f-01 in RRC idle mode can initiate an RRC connection establishment procedure with NR gNB 1f-02. When initiating the RRC connection establishment procedure, UE 1f-01 can start timer T300. Upon receiving an RRCSetup or RRCReject message from NR gNB 1f-02, or upon cell reselection or upper-layer abort of the RRC connection establishment procedure (when receiving an RRCSetup or RRCReject message, upon cell reselection, or upon upper-layer abort of the connection establishment), UE 1f-01 can stop the running timer T300.

[0174] In Operation 1f-30, timer T300, started by UE 1f-01 in Operation 1f-25, may expire.

[0175] When timer T300 expires, in operation 1f-35, UE 1f-01 can execute the following actions 1 and 2 in sequence.

[0176] According to embodiments of this disclosure, action 1 can be a first operation for handling connection failure. For example, the first operation for handling connection failure may be unrelated to the connection failure report. However, embodiments of this disclosure are not limited to the above examples. Furthermore, the first operation may be unrelated to VarConnEstFailReport.

[0177] The first operation for handling connection failures may include at least one of the following operations. Furthermore, multiple operations may be performed sequentially or without regard to order.

[0178] - Reset the MAC layer, release the MAC layer configuration, and rebuild the RLC layer for established radio bearers (RBs). (Reset MAC, release MAC configuration, and rebuild RLC for all established RBs)

[0179] - During the time period indicated by connEstFailOffsetValidity, when timer T300 expires for a consecutive number of connEstFailCounts on the same cell as the cell included in System Information Block 1 (SIB1) containing connEstFailureControl, the parameter Qoffsettemp for the relevant cell is used when cell selection and reselection are performed. (If, during the time period indicated by connEstFailOffsetValidity, T300 has expired for a consecutive number of connEstFailCounts on the same cell as connEstFailureControl included in SIB1, the parameter Qoffsettemp for the relevant cell is used when cell selection and reselection are performed according to TS 38.304 and TS 36.304.)

[0180] According to embodiments of this disclosure, action 2 can be a second operation for handling connection failures. For example, the second operation for handling connection failures can be related to a connection failure report. However, embodiments of this disclosure are not limited to the examples described above. Furthermore, the second operation can be related to VarConnEstFailReport.

[0181] The second operation for handling connection failures may include at least one of the following operations. Furthermore, multiple operations may be performed sequentially or consecutively, regardless of order.

[0182] - Discard everything in VarConnEstFailReport except for numberOfConnFail (Clear everything in VarConnEstFailReport except for numberOfConnFail, if any)

[0183] - When the UE has available connection establishment failure information in VarConnEstFailReport, and the registered PLMN (RPLMN) is not the same as the plmn-Identity stored in VarConnEstFailReport, reset numberOfConnFail to 0. (If the UE has available connection establishment failure information in VarConnEstFailReport, and if the RPLMN is not equal to the plmn-Identity stored in VarConnEstFailReport, then reset numberOfConnFail to 0.)

[0184] - Configure its fields as follows to store connection establishment failure information in VarConnEstFailReport (configure its fields as follows to store the following connection establishment failure information in VarConnEstFailReport):

[0185] 1) Configure the plmn-Identity to be a PLMN selected by the upper layer (see TS 23.122 and TS 24.501) from one or more PLMNs included in the plmn-IdentityList in SIB1.

[0186] 2) Based on available SSB measurements collected up to the point in time when the UE detects connection establishment failure, configure measResultFailedCell to include the global cell ID, tracking area code, physical cell ID, RSRP, and reference signal reception quality (RSRQ) of the failed cell.

[0187] 3) If available, configure measResultNeighCells in descending order of the sorting criteria used for cell reselection to include a maximum of the following number of neighboring cell measurements: 6 intra-frequency neighbors and 3 inter-frequency neighbors per frequency per RAT, and 3 inter-RAT neighbors per frequency / frequency set, and according to the following: for each included neighboring cell, include available optional fields (6 intra-frequency neighbors and 3 inter-frequency neighbors per frequency per RAT, and 3 inter-RAT neighbors per frequency / frequency set, and according to the following: for each included neighboring cell, include available optional fields).

[0188] 4) If available, configure locationInfo as follows (if available, set locationInfo as follows):

[0189] i) If available, configure commonLocationInfo to include detailed location information (set commonLocationInfo to include detailed location information if available)

[0190] ii) If available, configure bt-LocationInfo to include Bluetooth measurements sorted in descending order of Received Signal Strength Indicator (RSSI) of Bluetooth beacons.

[0191] iii) If available, configure wlan-LocationInfo to include wireless LAN (WLAN) measurements sorted in descending order of RSSI for WLAN access points (APs). (If available, set wlan-LocationInfo to include WLAN measurements sorted in descending order of RSSI for WLAN APs.)

[0192] iv) If available, configure sensor-LocationInfo to include sensor measurements.

[0193] 5) Configure perRAInfoList to indicate random access failure information (Set perRAInfoList to indicate random access failure information)

[0194] 6) When numberOfConnFail is less than 7, increment numberOfConnFail by 1 (if numberOfConnFail is less than 7, increment numberOfConnFail by 1).

[0195] - Notify the upper layer that the RRC connection establishment failed (the process ends at this point when the upper layer is notified of the RRC connection establishment failure).

[0196] When the UE 1f-01 according to the embodiments of this disclosure performs the second operation described above in sequence, two problems may occur.

[0197] Question 1: The value of numberOfConnFail may always be reset to 0.

[0198] -varConnEstFailReport consists of ConnEstFailReport and plmn-Identity. When the first execution is performed to discard everything included in VarConnEstFailReport except numberOfConnFail (clear everything included in VarConnEstFailReport except numberOfConnFail, if any), plmn-Identity stored in VarConnEstFailReport is discarded.

[0199] Therefore, because only numberOfConnFail is retained in VarConnEstFailReport, while plmn-Identity is discarded, the UE may have the inefficiency of always resetting numberOfConnFail to 0 when the UE has available connection establishment failure information in VarConnEstFailReport and RPLMN is not the same as plmn-Identity stored in VarConnEstFailReport (and if the UE has available connection establishment failure information in VarConnEstFailReport and if RPLMN is not equal to plmn-Identity stored in VarConnEstFailReport).

[0200] Question 2: In operation 1f-25, UE 1f-01 may perform an RRC connection establishment procedure for reasons other than PLMN reselection (e.g., when receiving a paging message from NR gNB 1f-02). The PLMN may be unnecessarily selected, causing the identifier of the selected PLMN to be configured in the VarConnEstFailReport. For example, when UE 1f-01 successfully performs the NAS registration procedure in operation 1f-03, receives an RRC connection release message (RRCRelease) from NR gNB 1f-02 in operation 1f-04, switches to RRC idle mode, and then performs an RRC connection establishment procedure in operation 1f-25 for reasons other than PLMN reselection, and then performs operations 1f-30 and 1f-35, PLMN reselection may be unnecessarily performed, resulting in the following operations.

[0201] -1) Configure the plmn-Identity to be a PLMN selected by the upper layer (see TS 23.122, TS 24.501) from the PLMNs included in the plmn-IdentityList in SIB1 (set the plmn-Identity to be a PLMN selected by the upper layer (see TS23.122, TS 24.501) from one or more PLMNs included in the plmn-IdentityList in SIB1).

[0202] In operation 1f-40, UE 1f-01 in RRC idle mode can initiate an RRC connection establishment procedure with NR gNB 1f-02. When initiating the RRC connection establishment procedure, UE 1f-01 can start timer T300 (the UE starts timer T300 when initiating this procedure).

[0203] In operation 1f-45, UE 1f-01 in RRC idle mode can send an RRCSetupRequest message to NR gNB 1f-02.

[0204] In Operation 1f-50, NR gNB 1f-02 can send an RRCSetup message to UE 1f-01 in RRC idle mode. UE 1f-01, upon receiving the RRCSetup message, can switch to RRC connected mode after applying the information included in the RRCSetup message.

[0205] In Operation 1f-55, when the connection establishment failure information is included in VarConnEstFailReport and the plmn-Identity stored in VarConnEstFailReport is the same as RPLMN, UE1f-01, which has switched to RRC connection mode, can send the connEstFailInfoAvailable indicator to NR gNB 1f-02 in the RRCSetupComplete message.

[0206] In Operation 1f-60, when the connection establishment failure information is included in VarConnEstFailReport and the plmn-Identity stored in VarConnEstFailReport is the same as RPLMN, UE1f-01 in RRC connection mode can send the connEstFailInfoAvailable indicator to NR gNB 1f-02 in the RRCReconfigurationComplete message or the RRCestablishmentComplete message.

[0207] In Operation 1f-65, NR gNB 1f-02 can send a UEInformationRequest message to UE 1f-01 by configuring connEstFailReportReq to true in the UEInformationRequest message.

[0208] In Operation 1f-70, when connEstFailReportReq is configured to true in the received UEInformationRequest message, connection establishment failure information is included in VarConnEstFailReport, and the plmn-Identity stored in VarConnEstFailReport is the same as RPLMN, UE 1f-01 can send a UEInformationResponse message to NR gNB 1f-02 by performing the following operations.

[0209] - Configure the timeSinceFailure property of VarConnEstFailReport to the time elapsed since the last connection establishment failure in NR (set the timeSinceFailure property in VarConnEstFailReport to the time elapsed since the last connection establishment failure in NR).

[0210] - Configure the connEstFailReport in the UEInformationResponse message to the value of connEstFailReport in VarConnEstFailReport (set the connEstFailReport in the UEInformationResponse message to the value of connEstFailReport in VarConnEstFailReport)

[0211] When the lower layer confirms that the UEInformationResponse message has been successfully sent, UE 1f-01 can discard connEstFailReport from VarConnEstFailReport (when the lower layer confirms that the UEInformationResponse message has been successfully delivered, connEstFailReport is discarded from VarConnEstFailReport).

[0212] Figure 1G This is a flowchart of the process by which a terminal (e.g., UE 1g-01) in an NR system according to an embodiment of the present disclosure collects RRC connection recovery failure information and reports it to NR gNB 1g-02.

[0213] According to embodiments of this disclosure, RRC connection recovery failure information can be interpreted in the same way as RRC connection establishment failure information.

[0214] refer to Figure 1G In operation 1g-03, UE 1g-01 can establish an RRC connection with NR gNB 1g-02 and is therefore in RRC connection mode (RRC_CONNECTED).

[0215] In operation 1g-04, NR gNB 1g-02 can send an RRCRelease message containing suspend configuration information (suspendConfig) to UE 1g-01.

[0216] In Operation 1g-05, a UE 1g-01 that receives an RRC Release message including suspend configuration information (suspendConfig) can switch to RRC Inactive mode (RRC_INACTIVE).

[0217] In Operation 1g-10, a UE 1g-01 in RRC inactive mode can perform a cell selection process to select a suitable cell to camp on.

[0218] In Operation 1g-20, UE 1g-01 in RRC inactive mode can perform a cell reselection process to find a more suitable cell.

[0219] In Operation 1g-25, UE 1g-01 in RRC inactive mode can initiate an RRC connection restoration procedure with NR gNB 1g-02. When initiating the RRC connection restoration procedure, UE 1g-01 can start timer T319 (timer T319 is started when the procedure is initiated). Upon receiving an RRCResume, RRCSetup, RRCRelease without suspendConfig, RRCRelease with suspendConfig, or RRCReject message from NR gNB 1g-02, or upon cell reselection or upper-layer abort of the RRC connection establishment procedure, UE 1g-01 can stop the running timer T319.

[0220] In Operation 1g-30, Timer T319, which was started in Operation 1g-25, may expire, or UE 1g-01 may receive an integrity check failure indication from the lower layer while Timer T319 is running.

[0221] Once timer T319 expires or an integrity check failure indication is received from the lower layer while timer T319 is running, UE 1g-01 can perform the following actions 1 and 2 in sequence during operation 1g-35.

[0222] According to embodiments of this disclosure, action 1 can be a first operation for handling connection failure. For example, the first operation for handling connection failure may be unrelated to the connection failure report. However, embodiments of this disclosure are not limited to the above examples. Furthermore, the first operation may be unrelated to VarConnEstFailReport.

[0223] The first operation for handling connection failures may include at least one of the following operations. Furthermore, multiple operations may be performed sequentially or without regard to order.

[0224] - Discard everything included in VarConnEstFailReport except numberOfConnFail (Clear everything included in VarConnEstFailReport except numberOfConnFail, if any)

[0225] - When the UE has available connection restoration failure information in the VarConnEstFailReport, and the RPLMN is not the same as the plmn-Identity stored in the VarConnEstFailReport, reset numberOfConnFail to 0. (If the UE has available connection restoration failure information in the VarConnEstFailReport, and if the RPLMN is not equal to the plmn-Identity stored in the VarConnEstFailReport, then reset numberOfConnFail to 0.)

[0226] - Store recovery connection establishment failure information in VarConnEstFailReport by configuring its fields as follows (store the following recovery connection establishment failure information in VarConnEstFailReport by setting its fields as follows):

[0227] 1) Configure the plmn-Identity to be a PLMN selected by the upper layer (see TS 23.122, TS 24.501) from the PLMNs included in the plmn-IdentityList in SIB1 (set the plmn-Identity to be a PLMN selected by the upper layer (see TS23.122, TS 24.501) from one or more PLMNs included in the plmn-IdentityList in SIB1).

[0228] 2) Based on available SSB measurements collected up to the time point before the UE detects connection establishment failure, configure measResultFailedCell to include the global cell ID, physical cell ID, RSRP, and RSRQ of the failed cell.

[0229] 3) If available, configure measResultNeighCells in descending order of the sorting criteria used for cell reselection to include a maximum of the following number of neighboring cell measurements: 6 intra-frequency neighbors and 3 inter-frequency neighbors per frequency per RAT, and 3 inter-RAT neighbors per frequency / frequency set, and according to the following: for each included neighboring cell, include available optional fields (6 intra-frequency neighbors and 3 inter-frequency neighbors per frequency per RAT, and 3 inter-RAT neighbors per frequency / frequency set, and according to the following: for each included neighboring cell, include available optional fields).

[0230] 4) If available, configure locationInfo as follows (if available, set locationInfo as follows):

[0231] i) If available, configure commonLocationInfo to include detailed location information (set commonLocationInfo to include detailed location information if available)

[0232] ii) If available, configure bt-LocationInfo to include Bluetooth measurements in descending order of the RSSI of the Bluetooth beacons (if available, set bt-LocationInfo to include Bluetooth measurements in descending order of the RSSI of the Bluetooth beacons).

[0233] iii) If available, configure wlan-LocationInfo to include WLAN measurement results sorted in descending order of WLAN AP RSSI (if available, set wlan-LocationInfo to include WLAN measurement results sorted in descending order of WLAN AP RSSI).

[0234] iv) If available, configure sensor-LocationInfo to include sensor measurements.

[0235] 5) Configure perRAInfoList to indicate random access failure information (Set perRAInfoList to indicate random access failure information)

[0236] 6) When numberOfConnFail is less than 7, increment numberOfConnFail by 1 (if numberOfConnFail is less than 7, increment numberOfConnFail by 1).

[0237] According to embodiments of this disclosure, action 2 can be a second operation for handling connection failures. For example, the second operation for handling connection failures can be related to a connection failure report. However, embodiments of this disclosure are not limited to the examples described above. Additionally, the second operation can be related to VarConnEstFailReport.

[0238] The second operation for handling connection failures may include at least one of the following operations. Furthermore, multiple operations may be performed sequentially or consecutively, regardless of order.

[0239] - An action is performed to transition to the RRC_IDLE state specified in 3GPP TS 38.3315.3.11 due to the release reason 'RRC recovery failed' (actions are performed regarding entering RRC_IDLE as specified in 3GPP TS 38.3315.3.11 due to the release reason 'RRC recovery failed').

[0240] When the UE 1g-01 according to the embodiments of this disclosure executes action 1 in sequence, two problems may occur.

[0241] Question 1: The value of numberOfConnFail may always be reset to 0.

[0242] -varConnEstFailReport consists of ConnEstFailReport and plmn-Identity. When the first execution is performed to discard all content in VarConnEstFailReport except numberOfConnFail (clear all content in VarConnEstFailReport except numberOfConnFail, if any), plmn-Identity stored in VarConnEstFailReport is discarded.

[0243] Therefore, since only numberOfConnFail is retained in VarConnEstFailReport and plmn-Identity is discarded, when the UE has available connection establishment failure information in VarConnEstFailReport and RPLMN is not the same as plmn-Identity stored in VarConnEstFailReport, resetting numberOfConnFail to 0 (if the UE has available connection establishment failure information in VarConnEstFailReport and if RPLMN is not equal to plmn-Identity stored in VarConnEstFailReport) is performed, the UE may always have the inefficiency of resetting numberOfConnFail to 0.

[0244] Question 2: UE 1g-01 in RRC inactive mode may not perform the PLMN selection process. Therefore, performing "Set plmn-Identity to a PLMN selected by the upper layer (see TS 23.122, TS 24.501) from one or more PLMNs included in the plmn-IdentityList in SIB1" may result in unnecessary PLMN reselection.

[0245] In operation 1g-36, UE 1g-01 is in RRC idle mode. In operation 1g-40, UE 1g-01 in RRC idle mode can initiate an RRC connection establishment procedure with NR gNB 1g-02. When initiating the RRC connection establishment procedure, UE 1g-01 can start timer T300 (the UE starts timer T300 when initiating this procedure).

[0246] In operation 1g-45, UE 1g-01 in RRC idle mode can send an RRCSetupRequest message to NR gNB 1g-02.

[0247] In Operation 1g-50, NR gNB 1g-02 can send an RRCSetup message to UE 1g-01 in RRC idle mode. UE 1g-01 that receives the RRCSetup message can switch to RRC connected mode after applying the information included in the RRCSetup message.

[0248] In Operation 1g-55, when the connection establishment failure information is included in VarConnEstFailReport and the plmn-Identity stored in VarConnEstFailReport is the same as RPLMN, UE1g-01, which has switched to RRC connection mode, can send the connEstFailInfoAvailable indicator to NR gNB 1g-02 in the RRCSetupComplete message.

[0249] In Operation 1g-60, when the connection establishment failure information is included in VarConnEstFailReport and the plmn-Identity stored in VarConnEstFailReport is the same as RPLMN, UE1g-01 in RRC connection mode can send the connEstFailInfoAvailable indicator to NR gNB 1g-02 in the RRCReconfigurationComplete message or the RRCestablishmentComplete message.

[0250] In Operation 1g-65, NR gNB 1g-02 can send a UEInformationRequest message to UE 1g-01 by configuring connEstFailReportReq to true in the UEInformationRequest message.

[0251] In Operation 1g-70, when connEstFailReportReq is configured to true in the received UEInformationRequest message, connection establishment failure information is included in VarConnEstFailReport, and the plmn-Identity stored in VarConnEstFailReport is the same as RPLMN, UE 1g-01 can send a UEInformationResponse message to NR gNB 1g-02 by performing the following operations.

[0252] - Configure the timeSinceFailure property of VarConnEstFailReport to the time elapsed since the last connection establishment failure in NR (set the timeSinceFailure property in VarConnEstFailReport to the time elapsed since the last connection establishment failure in NR).

[0253] - Configure the ConnEstFailReport in the UEInformationResponse message to the value of connEstFailReport in VarConnEstFailReport (set the connEstFailReport in the UEInformationResponse message to the value of connEstFailReport in VarConnEstFailReport)

[0254] When the lower layer confirms that the UEInformationResponse message has been successfully sent, UE 1g-01 can discard the connEstFailReport from VarConnEstFailReport (when the lower layer confirms that the UEInformationResponse message has been successfully delivered, the ConnEstFailReport is discarded from VarConnEstFailReport).

[0255] Figure 1H This is a flowchart illustrating the process by which a terminal (e.g., UE1h-01) in an NR system according to embodiments of the present disclosure collects RRC connection establishment failure information and reports it to NR gNB 1h-02.

[0256] refer to Figure 1H In operation 1h-03, UE 1h-01 can establish an RRC connection with NR gNB 1h-02, thus entering RRC connection mode (RRC_CONNECTED).

[0257] In operation 1h-04, NR gNB 1h-02 can send an RRCRelease message to UE 1h-01 that does not include suspend configuration information (suspendConfig).

[0258] In operation 1h-05, UE 1h-01 that receives an RRCLease message that does not include suspend configuration information (suspendConfig) can switch to RRC idle mode (RRC_IDLE).

[0259] In operation 1h-10, UE 1h-01 in RRC idle mode can perform the PLMN selection procedure. The AS layer of UE 1h-01 can report at least one available PLMN to the NAS layer either upon request from the NAS layer or spontaneously (in the UE, the AS will report available PLMNs to the NAS upon request from the NAS layer or spontaneously). Specifically, UE 1h-01 can scan all RF channels in the NR band according to its ability to find available PLMNs (the UE will scan all RF channels in the NR band according to its ability to find available PLMNs). For each carrier, UE 1h-01 can find the cell with the strongest signal strength and read system information from that cell in order to find at least one PLMN to which that cell belongs (on each carrier, the UE will search for the strongest cell and read its system information to determine which of one or more PLMNs the cell belongs to). When UE1h-01 is able to read at least one PLMN identifier in the cell with the strongest signal strength, UE1h-01 can report each found PLMN to the NAS layer as a high-quality PLMN, provided that the following high-quality conditions are met (if the UE is able to read one or more PLMN identifiers in the strongest cell, each found PLMN will be reported to the NAS as a high-quality PLMN (but without RSRP value), provided that the following high-quality criteria are met).

[0260] - High-quality conditions: For NR cells, the RSRP value is greater than or equal to -110dBm (For NR cells, the measured RSRP value should be greater than or equal to -110dBm).

[0261] When a found PLMN does not meet the above high-quality conditions, but UE 1h-01 can read the PLMN identifier, UE 1h-01 can report the RSRP measurement value and the PLMN identifier to the NAS layer (PLMNs that do not meet the high-quality criteria but whose PLMN identifiers the UE can read, along with their corresponding RSRP values, are reported to the NAS). Each measurement value reported to the NAS layer can be the value of each PLMN found in each cell (the quality measurement reported by the UE to the NAS should be the same for each PLMN found in a cell).

[0262] In response to a request from the NAS layer, the PLMN selection process may not be performed (the search for the PLMN can be stopped upon request from the NAS). UE 1h-01 can optimize the PLMN selection process by using stored information (e.g., information about frequency and cell parameters that may be obtained optionally from previously received measurement control information elements).

[0263] In operation 1h-15, when UE 1h-01 in RRC idle mode selects a PLMN, UE 1h-01 can perform a cell selection process to select a suitable cell for the PLMN so as to camp on that suitable cell (once the UE has selected a PLMN, the cell selection process will be performed so as to select a suitable cell for the PLMN to camp on).

[0264] During operation 1h-20, UE 1h-01 in RRC idle mode can perform a cell reselection process to find a more suitable cell.

[0265] In operation 1h-25, UE 1h-01, in RRC idle mode, can initiate an RRC connection establishment procedure with NR gNB1h-02. When initiating the RRC connection establishment procedure, UE 1h-01 can start timer T300. Upon receiving an RRCSetup or RRCReject message from NR gNB1h-02, or upon cell reselection or upper-layer abort of the RRC connection establishment procedure (when receiving an RRCSetup or RRCReject message, upon cell reselection, or upon upper-layer abort of the connection establishment), UE 1h-01 can stop the running timer T300.

[0266] During operation 1h-30, timer T300, started by UE 1h-01 during operation 1h-25, may expire.

[0267] When timer T300 expires, in operation 1h-35, UE 1h-01 can execute the following actions 1 and 2 in sequence.

[0268] According to embodiments of this disclosure, action 1 can be a first operation for handling connection failure. For example, the first operation for handling connection failure may be unrelated to the connection failure report. However, embodiments of this disclosure are not limited to the above examples. Furthermore, the first operation may be unrelated to VarConnEstFailReport.

[0269] The first operation for handling connection failures may include at least one of the following operations. Furthermore, multiple operations may be performed sequentially or consecutively, regardless of order: - Reset the MAC layer, release the MAC layer configuration, and re-establish the RLC layer for all established RBs (Reset MAC, release MAC configuration, and re-establish RLC for all established RBs).

[0270] - During the time period indicated by connEstFailOffsetValidity, when timer T300 expires for a consecutive number of connEstFailCounts on the same cell as the cell included in SIB1 that is under connEstFailureControl, the parameter Qoffsettemp for the relevant cell is used when cell selection and reselection are performed. (If T300 has expired for a consecutive number of connEstFailCounts on the same cell included in SIB1 by connEstFailureControl during the time period indicated by connEstFailOffsetValidity, the parameter Qoffsettemp for the relevant cell is used when cell selection and reselection are performed according to TS 38.304 and TS 36.304.)

[0271] According to embodiments of this disclosure, action 2 can be a second operation for handling connection failures. For example, the second operation for handling connection failures can be related to a connection failure report. However, embodiments of this disclosure are not limited to the examples described above. Additionally, the second operation can be related to VarConnEstFailReport.

[0272] The second operation for handling connection failures may include at least one of the following operations. Furthermore, multiple operations may be performed sequentially or consecutively, regardless of order.

[0273] - When the UE has available connection establishment failure information in VarConnEstFailReport and the RPLMN is not the same as the plmn-Identity stored in VarConnEstFailReport, numberOfConnFail is reset to 0. (If the UE has available connection establishment failure information in VarConnEstFailReport and the RPLMN is not equal to the plmn-Identity stored in VarConnEstFailReport, then numberOfConnFail is reset to 0; or if the failed cell is not the cell where the UE previously failed, then numberOfConnFail is reset to 0.)

[0274] To solve the above reference Figure 1FRegarding the problem described in this disclosure, in the embodiments, UE 1h-01 can first perform the above-described operation. Furthermore, if the cell previously camped by UE 1h-01 (hereinafter referred to as the previously camped cell) and the cell currently camped by UE 1h-01 (the currently camped cell) are changed when timer T300 expires, UE 1h-01 can reset numberOfConnFail to 0. That is, this is because NR gNB 1h-02 can only identify the number of times timer T300 of a cell has expired when UE 1h-01 accumulates the value of numberOfConnFail without changing the cell it camps on. If numberOfConnFail is not processed as described above, it may cause UE 1h-01 to report incorrect information to NR gNB 1h-02. For reference, UE 1h-01 can identify that the previously camped cell and the currently camped cell have been changed using at least one of the following methods.

[0275] Method 1: When the global cell identifier of the currently camped cell (or the current cell) is not the same as or different from the cell identifier and PLMN identifier stored in measResultFailedCell of VarConnEstFailReport, UE 1h-01 can identify that the previously camped cell and the currently camped cell have been changed.

[0276] - Global Cell Identifier: A unique identifier for an NR cell, consisting of the cellIdentity and the plmn-Identity of the first PLMN-identity in the plmn-Identity List. (Global Cell Identifier: A unique identifier for an NR cell. It consists of the cellIdentity and the plmn-Identity of the first PLMN-Identity in the plmn-Identity List in SIB1.)

[0277] Method 2: When the global cell identifier and the tracking area code mapped to it of the currently camped cell (or the current cell) do not belong to or are different from the cell identifier, PLMN identifier and tracking area code stored in measResultFailedCell of VarConnEstFailReport, UE 1h-01 can identify that the previously camped cell and the currently camped cell have been changed.

[0278] - The tracking region code mapped to the global cell identifier of the currently residing cell can refer to the tracking region code broadcast in the PLMN-IdentityInfo to which the global cell identifier broadcast in SIB1 belongs.

[0279] Method 3: When the cell identifier of the currently camped cell (current cell) does not belong to or is different from the cell identifier stored in measResultFailedCell of VarConnEstFailReport, UE 1h-01 can identify that the previously camped cell and the currently camped cell have been changed.

[0280] To solve the above reference Figure 1F Regarding the problem described in this disclosure, in an embodiment of the present disclosure, UE 1h-01 may perform the following operations after the above operations.

[0281] - Clear all content included in VarConnEstFailReport except numberOfConnFail (if any)

[0282] - Store the following connection establishment failure information in VarConnEstFailReport by configuring its fields as follows (store the following connection establishment failure information in VarConnEstFailReport by setting its fields as follows):

[0283] If available, configure plmn-Identity as RPLMN. Otherwise, configure plmn-Identity as a PLMN selected by the upper layer (see TS 23.122 and TS 24.501) from the PLMNs included in the plmn-IdentityList in SIB1 (if available, set plmn-Identity to the registered PLMN; otherwise, set plmn-Identity to a PLMN selected by the upper layer (see TS 23.122, TS 24.501) from one or more PLMNs included in the plmn-IdentityList in SIB1).

[0284] To solve the above reference Figure 1F Regarding issue 2 described, in this embodiment, UE 1h-01 can store the plmn-Identity value when it exists for the RPLMN, and can only perform the PLMN selection procedure when the plmn-Identity value does not exist. The PLMN selection procedure can always be performed.

[0285] - Based on available SSB measurements collected up to the time the UE detects connection establishment failure, configure measResultFailedCell to include the global cell identifier, tracking area code, physical cell ID, RSRP, and RSRQ of the failed cell.

[0286] - If available, configure measResultNeighCells in descending order of the sorting criteria used for cell reselection to include a maximum of the following neighbor cell measurements (if available, set measResultNeighCells in descending order of the sorting criteria used for cell reselection to include a maximum of the following neighbor cell measurements): 6 intra-frequency neighbors and 3 inter-frequency neighbors per frequency per RAT, and 3 inter-RAT neighbors per frequency / frequency set, and according to the following: for each included neighbor cell, include available optional fields (6 intra-frequency neighbors and 3 inter-frequency neighbors per frequency per RAT, and 3 inter-RAT neighbors per frequency / frequency set, and according to the following: for each included neighbor cell, include available optional fields).

[0287] - If available, configure locationInfo as follows (if available, set locationInfo as follows):

[0288] ◆ If available, configure commonLocationInfo to include detailed location information.

[0289] ◆ If available, configure bt-LocationInfo to include Bluetooth measurements sorted in descending order of Bluetooth beacon RSSI (if available, set bt-LocationInfo to include Bluetooth measurements in descending order of Bluetooth beacon RSSI).

[0290] ◆ If available, configure wlan-LocationInfo to include WLAN measurement results sorted in descending order of WLAN AP RSSI (if available, set wlan-LocationInfo to include WLAN measurement results sorted in descending order of WLAN AP RSSI).

[0291] ◆ If available, configure sensor-LocationInfo to include sensor measurement results.

[0292] - Configure perRAInfoList to indicate random access failure information (Set perRAInfoList to indicate random access failure information)

[0293] - When numberOfConnFail is less than 7, increment numberOfConnFail by 1 (if numberOfConnFail is less than 7, then increment numberOfConnFail by 1).

[0294] - Notify the upper layer of RRC connection establishment failure at the end of the process (notify the upper layer of RRC connection establishment failure at the end of the process).

[0295] During operation 1h-40, UE 1h-01, which is in RRC idle mode, can initiate an RRC connection establishment procedure with NR gNB1h-02. When initiating the RRC connection establishment procedure, UE 1h-01 can start timer T300 (the UE starts timer T300 when initiating this procedure).

[0296] During operation 1h-45, UE 1h-01 in RRC idle mode can send an RRCSetupRequest message to NR gNB 1h-02.

[0297] In operation 1h-50, NR gNB 1h-02 can send an RRCSetup message to UE 1h-01, which is in RRC idle mode. Upon receiving the RRCSetup message, UE 1h-01 can switch to RRC connected mode after applying the information included in the RRCSetup message.

[0298] In Operation 1h-55, when connection establishment failure information is included in VarConnEstFailReport and it is determined that the plmn-Identity stored in VarConnEstFailReport is the same as RPLMN, UE 1h-01, which has switched to RRC connection mode, can send the connEstFailInfoAvailable indicator to NR gNB1h-02 in the RRCSetupComplete message.

[0299] In operation 1h-60, when the connection establishment failure information is included in VarConnEstFailReport and it is determined that the plmn-Identity stored in VarConnEstFailReport is the same as RPLMN, UE1h-01 in RRC connection mode can send the connEstFailInfoAvailable indicator to NR gNB 1h-02 in the RRCReconfigurationComplete message or the RRCestablishmentComplete message.

[0300] In Operation 1h-65, NR gNB 1h-02 can send a UEInformationRequest message to UE 1h-01 by configuring connEstFailReportReq to true in the UEInformationRequest message.

[0301] In operation 1h-70, when connEstFailReportReq is configured to true in the received UEInformationRequest message, connection establishment failure information is included in VarConnEstFailReport, and it is determined that the plmn-Identity stored in VarConnEstFailReport is the same as RPLMN, UE 1h-01 can send a UEInformationResponse message to NR gNB 1h-02 by performing the following operations.

[0302] - Configure the timeSinceFailure in VarConnEstFailReport to the time elapsed since the last connection establishment failure in NR (set the timeSinceFailure in VarConnEstFailReport to the time elapsed since the last connection establishment failure in NR)

[0303] - Configure the ConnEstFailReport in the UEInformationResponse message to the value of connEstFailReport in VarConnEstFailReport (set the connEstFailReport in the UEInformationResponse message to the value of connEstFailReport in VarConnEstFailReport)

[0304] When the lower layer confirms that the UEInformationResponse message has been successfully sent, UE 1h-01 can discard ConnEstFailReport from VarConnEstFailReport.

[0305] Figure 1I This is a flowchart illustrating the process by which a UE 1i-01 in an NR system according to an embodiment of the present disclosure collects RRC connection recovery failure information and reports it to an NR gNB 1i-02.

[0306] According to embodiments of this disclosure, RRC connection recovery failure information can be interpreted in the same way as RRC connection establishment failure information.

[0307] refer to Figure 1I In operation 1i-03, UE 1i-01 can establish an RRC connection with NR gNB 1i-02 and is therefore in RRC connection mode (RRC_CONNECTED).

[0308] In operation 1i-04, NR gNB 1i-02 can send an RRCRelease message containing suspend configuration information (suspendConfig) to UE 1i-01.

[0309] In Operation 1i-05, UE 1i-01 that receives an RRC Release message including suspend configuration information (suspendConfig) can switch to RRC Inactive mode (RRC_INACTIVE).

[0310] In Operation 1i-10, UE 1i-01 in RRC inactive mode can perform a cell selection process to select a suitable cell to camp on.

[0311] In Operation 1i-20, UE 1i-01 in RRC inactive mode can perform a cell reselection process to find a more suitable cell.

[0312] In Operation 1i-25, UE 1i-01 in RRC inactive mode can initiate an RRC connection restoration procedure with NR gNB 1i-02. When initiating the RRC connection restoration procedure, UE 1i-01 can start timer T319 (timer T319 is started when the procedure is initiated). When UE 1i-01 receives an RRCResume, RRCSetup, RRCRelease without suspendConfig, RRCRelease with suspendConfig, or RRCReject message from NR gNB 1i-02, or when the cell reselection or upper layer aborts the RRC connection establishment procedure, UE 1i-01 can stop the running timer T319.

[0313] In Operation 1i-30, Timer T319, started by UE 1i-01 in Operation 1i-25, may expire, or UE 1i-01 may receive an integrity check failure indication from the lower layer while Timer T319 is running.

[0314] Once timer T319 started by UE 1i-01 expires or an integrity check failure indication is received from the lower layer while timer T319 is running, UE 1i-01 can perform the following actions 1 and 2 in sequence during operation 1i-35.

[0315] According to embodiments of this disclosure, action 1 can be a first operation for handling connection failure. For example, the first operation for handling connection failure may be unrelated to the connection failure report. However, embodiments of this disclosure are not limited to the above examples. Furthermore, the first operation may be unrelated to VarConnEstFailReport.

[0316] The first operation for handling connection failures may include at least one of the following operations. Furthermore, multiple operations may be performed sequentially or without regard to order.

[0317] - When UE 1i-01 has available connection recovery failure information in VarConnEstFailReport and the RPLMN is not the same as the plmn-Identity stored in VarConnEstFailReport, numberOfConnFail is reset to 0. Alternatively, when the failed cell is not the cell where UE 1i-01 previously failed, numberOfConnFail is reset to 0. (If the UE has available connection recovery failure information in VarConnEstFailReport and the RPLMN is not equal to the plmn-Identity stored in VarConnEstFailReport, then numberOfConnFail is reset to 0; or if the failed cell is not the cell where the UE previously failed, then numberOfConnFail is reset to 0.)

[0318] To solve the above reference Figure 1G Regarding the problem described in this disclosure, in the embodiments, UE 1i-01 can first perform the above-described operation. Furthermore, when timer T319 expires, or in the event of an integrity check failure during the operation of timer T319, when the previously camped cell and the currently camped cell change, UE 1i-01 can reset numberOfConnFail to 0. For reference, the foregoing embodiments can be used by the UE to identify when the previously camped cell and the currently camped cell have changed.

[0319] To solve the above reference Figure 1G Regarding the problem described in this disclosure, in the embodiments of this disclosure, UE 1i-01 may perform the following operations after the above operations.

[0320] ● Remove all content from VarConnEstFailReport except numberOfConnFail (remove all content from VarConnEstFailReport except numberOfConnFail), if any.

[0321] - Configure its fields to store the following connection failure information in VarConnEstFailReport (configure its fields to store the following connection recovery failure information in VarConnEstFailReport as follows):

[0322] ■ If available, configure plmn-Identity as RPLMN (set plmn-Identity to the registered PLMN).

[0323] To solve the above referenceFigure 1G Regarding the described problem 2, in this embodiment, UE 1i-01 can configure the plmn-Identity value for the RPLMN in the VarConnEstFailReport. That is, UE 1i-01 in RRC inactive mode can configure the plmn-Identity value for the RPLMN in the VarConnEstFailReport without performing the PLMN selection process. When the PLMN reselection process is performed, the aforementioned embodiment can be referred to... Figure 1G use.

[0324] ■ Based on the available SSB measurements collected until the UE 1i-01 detects connection establishment failure, configure measResultFailedCell to include the global cell identifier, tracking area code, physical cell ID, RSRP, and RSRQ of the failed cell.

[0325] ■ If available, configure measResultNeighCells in descending order of the sorting criteria used for cell reselection to include a maximum of the following neighbor cell measurements: 6 intra-frequency neighbors and 3 inter-frequency neighbors per frequency per RAT, and 3 inter-RAT neighbors per frequency / frequency set, and according to the following: For each included neighbor cell, include available optional fields (6 intra-frequency neighbors and 3 inter-frequency neighbors per frequency per RAT, and 3 inter-RAT neighbors per frequency / frequency set, and according to the following: For each included neighbor cell, include available optional fields).

[0326] ■ If available, configure locationInfo as follows (If available, set locationInfo as follows):

[0327] ◆ If available, configure commonLocationInfo to include detailed location information.

[0328] ◆ If available, configure bt-LocationInfo to include Bluetooth measurements sorted in descending order of Bluetooth beacon RSSI (if available, set bt-LocationInfo to include Bluetooth measurements in descending order of Bluetooth beacon RSSI).

[0329] ◆ If available, configure wlan-LocationInfo to include WLAN measurement results sorted in descending order of WLAN AP RSSI (if available, set wlan-LocationInfo to include WLAN measurement results sorted in descending order of WLAN AP RSSI).

[0330] ◆ If available, configure sensor-LocationInfo to include sensor measurement results.

[0331] ■ Configure perRAInfoList to indicate random access failure information (Set perRAInfoList to indicate random access failure information)

[0332] ■ When numberOfConnFail is less than 7, increment numberOfConnFail by 1 (if numberOfConnFail is less than 7, increment numberOfConnFail by 1).

[0333] According to embodiments of this disclosure, action 2 can be a second operation for handling connection failures. For example, the second operation for handling connection failures can be related to a connection failure report. However, embodiments of this disclosure are not limited to the examples described above. Additionally, the second operation can be related to VarConnEstFailReport.

[0334] The second operation for handling connection failures may include at least one of the following operations. Furthermore, multiple operations may be performed sequentially or consecutively, regardless of order.

[0335] - The action specified in 3GPP TS 38.331 5.3.11 is executed because of the release reason 'RRC recovery failed' (the action specified in 3GPP TS 38.331 5.3.11 is executed when entering RRC_IDLE because of the release reason 'RRC recovery failed').

[0336] In operation 1i-36, UE 1i-01 is in RRC idle mode. In operation 1i-40, UE 1i-01 in RRC idle mode can initiate an RRC connection establishment procedure with NR gNB 1i-02. When initiating the RRC connection establishment procedure, UE 1i-01 can start timer T300 (the UE starts timer T300 when initiating this procedure).

[0337] In operation 1i-45, UE 1i-01 in RRC idle mode can send an RRCSetupRequest message to NR gNB 1i-02.

[0338] In Operation 1i-50, NR gNB 1i-02 can send an RRCSetup message to UE 1i-01 in RRC idle mode. UE 1i-01 that receives the RRCSetup message can switch to RRC connected mode after applying the information included in the RRCSetup message.

[0339] In Operation 1i-55, when connection establishment failure information is included in VarConnEstFailReport and it is determined that the plmn-Identity stored in VarConnEstFailReport is the same as RPLMN, UE 1i-01, which has switched to RRC connection mode, can send the connEstFailInfoAvailable indicator to NR gNB1i-02 in the RRCSetupComplete message.

[0340] In operation 1i-60, when connection establishment failure information is included in VarConnEstFailReport and it is determined that the plmn-Identity stored in VarConnEstFailReport is the same as RPLMN, UE 1i-01 in RRC connection mode can send a connEstFailInfoAvailable indicator to NR gNB 1i-02 in an RRCReconfigurationComplete message or an RRCestablishmentComplete message.

[0341] In Operation 1i-65, NR gNB 1i-02 can send a UEInformationRequest message to UE 1i-01 by configuring connEstFailReportReq to true in the UEInformationRequest message.

[0342] In Operation 1i-70, when connEstFailReportReq is configured to true in the received UEInformationRequest message, connection establishment failure information is included in VarConnEstFailReport, and it is determined that the plmn-Identity stored in VarConnEstFailReport is the same as RPLMN, UE 1i-01 can send a UEInformationResponse message to NR gNB 1i-02 by performing the following operations.

[0343] - Configure the timeSinceFailure property of VarConnEstFailReport to the time elapsed since the last connection establishment failure in NR (set the timeSinceFailure property in VarConnEstFailReport to the time elapsed since the last connection establishment failure in NR).

[0344] - Configure the ConnEstFailReport in the UEInformationResponse message to the value of connEstFailReport in VarConnEstFailReport (set the connEstFailReport in the UEInformationResponse message to the value of connEstFailReport in VarConnEstFailReport)

[0345] When the lower layer confirms that the UEInformationResponse message has been successfully sent, UE 1i-01 can discard ConnEstFailReport from VarConnEstFailReport (when the lower layer confirms that the UEInformationResponse message has been successfully delivered, ConnEstFailReport is discarded from VarConnEstFailReport).

[0346] Figure 1J This is a flowchart of a UE operation in an NR system according to embodiments of the present disclosure, in which a UE collects RRC connection establishment failure information and reports it to the NR gNB.

[0347] refer to Figure 1J A UE in RRC idle mode can initiate an RRC connection establishment procedure with an NR gNB. When initiating the RRC connection establishment procedure, the UE can start timer T300 in operation 1j-05 (when this procedure is initiated, the UE starts timer T300).

[0348] In operation 1j-10, timer T300, which was started in operation 1j-05, may expire.

[0349] In operation 1j-15, the UE may perform the following action 1. According to embodiments of this disclosure, action 1 may be a first operation for handling connection failure. The first operation for handling connection failure may include at least one of the following operations. Furthermore, multiple operations may be performed sequentially or consecutively without regard to order.

[0350] Action 1

[0351] - Reset the MAC layer, release its configuration, and rebuild the RLC layer for all established RBs (Reset MAC, release MAC configuration, and rebuild RLC for all established RBs).

[0352] - During the time period indicated by connEstFailOffsetValidity, when timer T300 expires for a consecutive number of connEstFailCounts on the same cell as the cell included in System Information Block 1 (SIB1) containing connEstFailureControl, the parameter Qoffsettemp for the relevant cell is used when cell selection and reselection are performed. (If, during the time period indicated by connEstFailOffsetValidity, T300 has expired for a consecutive number of connEstFailCounts on the same cell included in SIB1 under connEstFailureControl, the parameter Qoffsettemp for the relevant cell is used when cell selection and reselection are performed according to TS 38.304 and TS 36.304.)

[0353] In operation 1j-20, the UE can determine whether the following condition 1 is met.

[0354] Condition 1

[0355] - When the UE has available connection establishment failure information in VarConnEstFailReport, and the RPLMN is not the same as the plmn-Identity stored in VarConnEstFailReport, or the failed cell is not the cell the UE previously failed in (if the UE has available connection establishment failure information in VarConnEstFailReport, and if the RPLMN is not equal to the plmn-Identity stored in VarConnEstFailReport, or if the failed cell is not the cell the UE previously failed in)

[0356] When the UE determines that condition 1 above is met in operation 1j-20, the UE can reset numberOfConnFail to 0 in operation 1j-21. Furthermore, in operation 1j-25, the UE can discard (clear) all information stored in VarConnEstFailReport except for numberOfConnFail.

[0357] If the UE determines in operation 1j-20 that condition 1 above is not met, in operation 1j-25, the UE may discard all information stored in VarConnEstFailReport except for numberOfConnFail. That is, the UE may not reset numberOfConnFail to 0.

[0358] In operation 1j-30, the UE can determine whether the following condition 2 is met.

[0359] Condition 2

[0360] Is RPLMN available? (Is the registered PLMN available?)

[0361] When the UE determines that condition 2 is met in operation 1j-30, the UE can configure plmn-Identity for RPLMN in operation 1j-35. Furthermore, in operation 1j-45, the UE can perform the following action 2. That is, the UE can store connection establishment failure information in VarConnEstFailReport by performing the following action 2. According to embodiments of this disclosure, action 2 may include at least one of the following operations. Furthermore, multiple operations may be performed sequentially or without regard to order.

[0362] Action 2

[0363] ■ Based on available SSB measurements collected up to the point in time when the UE detects connection establishment failure, configure measResultFailedCell to include the global cell ID, tracking area code, physical cell ID, RSRP, and RSRQ of the failed cell.

[0364] ■ If available, configure measResultNeighCells in descending order of the sorting criteria used for cell reselection to include a maximum of the following neighbor cell measurements (if available, set measResultNeighCells in descending order of the sorting criteria used for cell reselection to include a maximum of the following neighbor cell measurements): 6 intra-frequency neighbors and 3 inter-frequency neighbors per frequency per RAT, and 3 inter-RAT neighbors per frequency / frequency set, and according to the following: for each included neighbor cell, include available optional fields (6 intra-frequency neighbors and 3 inter-frequency neighbors per frequency per RAT, and 3 inter-RAT neighbors per frequency / frequency set, and according to the following: for each included neighbor cell, include available optional fields).

[0365] ■ If available, configure locationInfo as follows (If available, set locationInfo as follows):

[0366] ◆ If available, configure commonLocationInfo to include detailed location information.

[0367] ◆ If available, configure bt-LocationInfo to include Bluetooth measurements sorted in descending order of Bluetooth beacon RSSI (if available, set bt-LocationInfo to include Bluetooth measurements in descending order of Bluetooth beacon RSSI).

[0368] ◆ If available, configure wlan-LocationInfo to include WLAN measurement results sorted in descending order of WLAN AP RSSI (if available, set wlan-LocationInfo to include WLAN measurement results sorted in descending order of WLAN AP RSSI).

[0369] ◆ If available, configure sensor-LocationInfo to include sensor measurement results.

[0370] ■ Configure perRAInfoList to indicate random access failure information (Set perRAInfoList to indicate random access failure information)

[0371] ■ When numberOfConnFail is less than 7, increment numberOfConnFail by 1 (if numberOfConnFail is less than 7, increment numberOfConnFail by 1).

[0372] - Notify the upper layer of RRC connection establishment failure at the end of the process (notify the upper layer of RRC connection establishment failure at the end of the process).

[0373] When the UE determines in Operation 1j-30 that condition 2 is not met, in Operation 1j-40, the UE can configure the plmn-Identity in the VarConnEstFailReport to be a PLMN selected by the upper layer from the PLMNs included in the plmn-IdentityList in the current cell's SIB1 (setting the plmn-Identity to be a PLMN selected by the upper layer (see TS23.122, TS 24.501) from one or more PLMNs included in the plmn-IdentityList in SIB1). Furthermore, in Operation 1j-45, the UE can perform the described action 2.

[0374] In Operation 1j-50, the UE can switch to (enter) RRC connection mode.

[0375] In Operation 1j-55, the UE can send connEstFailInfoAvailable to the NR gNB in ​​the RRCSetupComplete, RRCResumeComplete, RRCReestablishmentComplete, or RRCReconfigurationComplete messages.

[0376] In Operation 1j-60, the UE can receive a UEInformationRequest message including connEstFailReportReq from the NR gNB.

[0377] In Operation 1j-65, the UE can send a UEInformationResponse message containing connEstFailReport to the NR gNB.

[0378] Figure 1K This is a flowchart of a UE operation in an NR system according to embodiments of the present disclosure, in which a UE collects RRC connection establishment failure information and reports it to the NR gNB.

[0379] refer to Figure 1K A UE in RRC inactive mode can initiate an RRC connection restoration procedure with the NR gNB. When initiating the RRC connection restoration procedure, the UE can start timer T319 in operation 1k-05 (timer T319 is started when the procedure is initiated).

[0380] In Operation 1k-10, when Timer T319, started in Operation 1k-05, expires, or when Timer T319 is running, the UE can receive an integrity check failure indication from the lower layer.

[0381] In operation 1k-15, the UE can determine whether the following condition 1 is met.

[0382] Condition 1

[0383] - When the UE has available connection establishment failure information in VarConnEstFailReport, and the RPLMN is not the same as the PLMN identifier stored in VarConnEstFailReport, or the failed cell is not the cell the UE previously failed in (if the UE has available connection establishment failure information in VarConnEstFailReport, and if the RPLMN is not equal to the plmn-Identity stored in VarConnEstFailReport, or if the failed cell is not the cell the UE previously failed in)

[0384] If the UE determines that condition 1 is met in operation 1k-15, the UE can reset numberOfConnFail to 0 in operation 1k-20. Furthermore, in operation 1k-25, the UE can discard all information stored in VarConnEstFailReport except for numberOfConnFail.

[0385] If the UE determines that the condition is not met in Operation 1k-15, in Operation 1k-25, the UE may discard all information stored in VarConnEstFailReport except for numberOfConnFail. In other words, the UE may not reset numberOfConnFail to 0.

[0386] In Operation 1k-30, the UE can configure and store the plmn-Identity for RPLMN in VarConnEstFailReport.

[0387] In operation 1k-35, the UE can perform the following action 1. That is, the UE can store connection recovery failure information in VarConnEstFailReport by performing the following action 1. According to embodiments of this disclosure, action 1 may include at least one of the following operations. Furthermore, multiple operations may be performed sequentially or in any order.

[0388] Action 1

[0389] ■ Based on available SSB measurements collected up to the moment when UE 1i-01 detects connection establishment failure, configure measResultFailedCell to include the global cell identifier, tracking area code, physical cell ID, RSRP, and RSRQ of the failed cell.

[0390] ■ If available, configure measResultNeighCells in descending order of the sorting criteria used for cell reselection to include a maximum of the following neighbor cell measurements: 6 intra-frequency neighbors and 3 inter-frequency neighbors per frequency per RAT, and 3 inter-RAT neighbors per frequency / frequency set, and according to the following: For each included neighbor cell, include available optional fields (6 intra-frequency neighbors and 3 inter-frequency neighbors per frequency per RAT, and 3 inter-RAT neighbors per frequency / frequency set, and according to the following: For each included neighbor cell, include available optional fields).

[0391] ■ If available, configure locationInfo as follows (If available, set locationInfo as follows):

[0392] ◆ If available, configure commonLocationInfo to include detailed location information.

[0393] ◆ If available, configure bt-LocationInfo to include Bluetooth measurements sorted in descending order of Bluetooth beacon RSSI (if available, set bt-LocationInfo to include Bluetooth measurements in descending order of Bluetooth beacon RSSI).

[0394] ◆ If available, configure wlan-LocationInfo to include WLAN measurement results sorted in descending order of WLAN AP RSSI (if available, set wlan-LocationInfo to include WLAN measurement results sorted in descending order of WLAN AP RSSI).

[0395] ◆ If available, configure sensor-LocationInfo to include sensor measurement results.

[0396] ■ Configure perRAInfoList to indicate random access failure information (Set perRAInfoList to indicate random access failure information)

[0397] ■ When numberOfConnFail is less than 7, increment numberOfConnFail by 1 (if numberOfConnFail is less than 7, then increment numberOfConnFail by 1).

[0398] - Notify the upper layer of RRC connection establishment failure at the end of the process (notify the upper layer of RRC connection establishment failure at the end of the process).

[0399] In Operation 1k-40, the UE can switch to RRC connection mode.

[0400] In Operation 1k-45, the UE can send connEstFailInfoAvailable to the NR gNB in ​​the RRCSetupComplete, RRCResumeComplete, RRCReestablishmentComplete, or RRCReconfigurationComplete messages.

[0401] In Operation 1k-50, the UE can receive a UEInformationRequest message, which includes a connection failure report request, from the NR gNB.

[0402] In Operation 1k-55, the UE can send a UEInformationResponse message to the NR gNB that includes a connection failure report.

[0403] Figure 1L This is a block diagram illustrating the internal structure of a UE according to an embodiment of the present disclosure.

[0404] refer to Figure 1L The UE may include a radio frequency (RF) processor 11-10, a baseband processor 11-20, a storage 11-30, and a controller 11-40. However, the internal structure of the UE is not limited to... Figure 1L The components shown can be compared with... Figure 1L The components shown are implemented using more components.

[0405] RF processors 11-10 can perform functions such as band-to-band conversion and amplification to transmit or receive signals on a radio channel. That is, RF processors 11-10 can up-convert baseband signals provided by baseband processors 11-20 into RF band signals and transmit these signals through an antenna, and can down-convert RF band signals received through the antenna back into baseband signals. For example, RF processors 11-10 may include transmit filters, receive filters, amplifiers, mixers, oscillators, digital-to-analog converters (DACs), and analog-to-digital converters (ADCs). Although in Figure 1L Only one antenna is shown, but the UE may include multiple antennas. Furthermore, RF processors 11-10 may include multiple RF chains. Additionally, RF processors 11-10 can perform beamforming. For beamforming, RF processors 11-10 can adjust the phase and amplitude of signals transmitted and received through multiple antennas or antenna elements. Furthermore, RF processors 11-10 can perform MIMO and can receive multiple layers during MIMO operation.

[0406] Baseband processors 11-20 can perform conversion functions between baseband signals and bit strings according to the system's physical layer standard. For example, during data transmission, baseband processors 11-20 can generate complex symbols by encoding and modulating the transmitted bit string. Furthermore, during data reception, baseband processors 11-20 can reconstruct the received bit string by demodulating and decoding the baseband signal provided from RF processors 11-10. For example, according to an OFDM scheme, during data transmission, baseband processors 11-20 can generate complex symbols by encoding and modulating the transmitted bit string, map the complex symbols to subcarriers, and then configure OFDM symbols through inverse fast Fourier transform (IFFT) operations and cyclic prefix (CP) insertion. Furthermore, during data reception, baseband processors 11-20 can segment the baseband signal provided from RF processors 11-10 in units of OFDM symbols, reconstruct the signal mapped to subcarriers through fast Fourier transform (FFT) operations, and then reconstruct the received bit string through demodulation and decoding.

[0407] Baseband processor 1l-20 and RF processor 1l-10 transmit and receive signals as described above. Therefore, baseband processor 1l-20 and RF processor 1l-10 can be referred to as transmitters, receivers, transceivers, or communicators. Furthermore, at least one of baseband processor 1l-20 or RF processor 1l-10 may include multiple communication modules to support a variety of different radio access technologies. Additionally, at least one of baseband processor 1l-20 or RF processor 1l-10 may include multiple communication modules to process signals in different frequency bands. For example, different radio access technologies may include wireless LAN (e.g., IEEE 802.11), cellular networks (e.g., LTE), etc. Furthermore, different frequency bands may include ultra-high frequency (SHF) bands (e.g., 2.0 NRHz or NRhz) and millimeter wave (mmWave) bands (e.g., 60 GHz).

[0408] Storage 1l-30 can store data such as basic programs, application programs, or configuration information used for UE operation. Specifically, storage 1l-30 can store information related to a second access node performing wireless communication using a second radio access technology. Storage 1l-30 can provide the stored data in response to a request from controller 1l-40. Storage 1l-30 can be configured with storage media such as read-only memory (ROM), random access memory (RAM), hard disk, optical disc ROM (CD-ROM), digital multifunction disc (DVD), or a combination of storage media. Furthermore, storage 1l-30 may include multiple memories.

[0409] Controller 11-40 can control the overall operation of the UE. For example, controller 11-40 can send and receive signals through baseband processor 11-20 and RF processor 11-10. Furthermore, controller 11-40 can write data to and read data from storage 11-30. For this purpose, controller 11-40 may include at least one processor 11-42. For example, controller 11-40 may include a communication processor (CP) for performing communication control and an application processor (AP) for controlling upper layers (such as applications). Furthermore, controller 11-40 can control the UE to perform the aforementioned methods of collecting and reporting RRC connection establishment and recovery failure information. Moreover, at least one component of the UE can be implemented as a single chip.

[0410] Figure 1M This is a block diagram illustrating the architecture of an NR base station according to an embodiment of the present disclosure.

[0411] refer to Figure 1M An NR base station may include an RF processor 1m-10, a baseband processor 1m-20, a backhaul communicator 1m-30, a storage unit 1m-40, and a controller 1m-50. However, the internal structure of the base station is not limited to... Figure 1M The components shown can be compared with... Figure 1M The components shown are implemented using more components.

[0412] The RF processor 1m-10 performs functions such as signal band conversion and amplification to transmit and receive signals on a radio channel. That is, the RF processor 1m-10 can up-convert baseband signals provided by the baseband processor 1m-20 to RF band signals and transmit these signals through an antenna, and can down-convert RF band signals received through the antenna back to baseband signals. For example, the RF processor 1m-10 may include transmit filters, receive filters, amplifiers, mixers, oscillators, DACs, and ADCs. Although in Figure 1M Only one antenna is shown, but the first access node may include multiple antennas. Furthermore, the RF processor 1m-10 may include multiple RF chains. Additionally, the RF processor 1m-10 can perform beamforming. For beamforming, the RF processor 1m-10 can adjust the phase and amplitude of signals transmitted and received through multiple antennas or antenna elements. The RF processor 1m-10 can perform DL MIMO operation by transmitting one or more layers.

[0413] The baseband processor 1m-20 can perform the conversion function between baseband signals and bit strings according to the physical layer standard of the first radio access technology. For example, during data transmission, the baseband processor 1m-20 can generate complex symbols by encoding and modulating the transmitted bit string. Furthermore, during data reception, the baseband processor 1m-20 can reconstruct the received bit string by demodulating and decoding the baseband signal provided from the RF processor 1m-10. For example, according to the OFDM scheme, during data transmission, the baseband processor 1m-20 can generate complex symbols by encoding and modulating the transmitted bit string, map the complex symbols to subcarriers, and then configure the OFDM symbols through IFFT operations and CP insertion. Furthermore, during data reception, the baseband processor 1m-20 can segment the baseband signal provided from the RF processor 1m-10 into OFDM symbol units, reconstruct the signal mapped to the subcarriers through FFT operations, and then reconstruct the received bit string through demodulation and decoding. The baseband processor 1m-20 and the RF processor 1m-10 can transmit and receive signals as described above. Therefore, the baseband processor 1m-20 and the RF processor 1m-10 can be referred to as transmitters, receivers, transceivers, communicators, or wireless communicators.

[0414] The 1m-30 backhaul communicator provides an interface for communicating with other nodes in the network. In other words, the 1m-30 backhaul communicator can convert bit strings sent from the primary base station to another node (e.g., a secondary base station, the core network, etc.) into physical signals, and convert physical signals received from another node into bit strings.

[0415] Storage 1m-40 can store data such as basic procedures, application programs, or configuration information used for the operation of the main base station. Specifically, storage 1m-40 can store information about bearers assigned to connected UEs, measurement results reported from connected UEs, etc. Furthermore, storage 1m-40 can store information as a reference for determining whether to provide or terminate multiple connections to a UE. Storage 1m-40 can provide the stored data in response to a request from controller 1m-50. Storage 1m-40 can include storage media such as ROM, RAM, hard disk, CD-ROM, and DVD, or a combination of storage media. Additionally, storage 1m-40 can include multiple memories.

[0416] Controller 1m-50 controls the overall operation of the main base station. For example, controller 1m-50 can transmit and receive signals via baseband processor 1m-20 and RF processor 1m-10 or via backhaul communicator 1m-30. Furthermore, controller 1m-50 can write data to and read data from storage 1m-40. For this purpose, controller 1m-50 may include at least one processor 1m-52. Additionally, controller 1m-50 can control the base station to perform the aforementioned methods for collecting and reporting RRC connection establishment and recovery failure information. Furthermore, at least one component of the base station can be implemented as a single chip.

[0417] The methods of embodiments of this disclosure as described in the claims or specification of this disclosure can be implemented in hardware, software, or a combination of hardware and software.

[0418] When these methods are implemented in software, a non-transitory, semi-transitory, or transient computer-readable storage medium may be provided to store one or more programs (software modules). One or more programs stored in the non-transitory computer-readable storage medium are configured to be executable by one or more processors included in an electronic device. The one or more programs include instructions to cause the electronic device to perform the methods of embodiments of this disclosure as set forth in the claims or specification.

[0419] Such a program (software module or software) can be stored in RAM, such as flash memory, ROM, electrically erasable programmable ROM (EEPROM), disk storage devices, CD-ROM, DVD, other types of optical storage devices, or non-volatile memory in magnetic tape cartridges. Alternatively, the program can be stored in a memory that is a combination of some or all of the above-mentioned storage media. Furthermore, multiple such memories may be included.

[0420] Furthermore, the program can be stored in an attachable storage device that can be accessed via a communication network such as the Internet, intranet, LAN, WLAN, or storage area network (SAN), or a combination thereof. The storage device can access the device executing embodiments of this disclosure via an external port. Additionally, a separate storage device on the communication network can also access the device executing embodiments of this disclosure.

[0421] Embodiments of this disclosure provide an apparatus and method for efficiently collecting and reporting RRC connection configuration and recovery failure information in a wireless communication system.

[0422] In embodiments of this disclosure, depending on the described embodiments of this disclosure, elements in this disclosure may be expressed in singular or plural form. However, singular or plural expressions have been suitably chosen for the purposes of description, and this disclosure is not limited to singular or plural elements; elements represented as plural may be configured as a single element, or elements represented as singular may be configured as plural elements.

[0423] Although this disclosure has been shown and described with reference to various embodiments thereof, those skilled in the art will understand that various changes in form and detail may be made to this disclosure without departing from the spirit and scope of this disclosure as defined by the appended claims and their equivalents.

Claims

1. A terminal for transmitting signals in a wireless communication system, the terminal comprising: transceiver; and At least one processor is configured as follows: A timer is started when the Radio Resource Control (RRC) connection establishment process is initiated. If the timer expires, it is determined whether at least one of a first condition or a second condition is met. The first condition includes the condition that the terminal has available connection failure information in the information container and the registered Public Land Mobile Network (PLMN) is not equal to the PLMN identifier included in the information container. The second condition includes the condition that the current cell is not equal to the cell in which the connection failure occurred. If at least one of the first or second conditions is met, the count of connection failures included in the information container is set to 0, and After determining whether at least one of the first or second conditions is met, clear the contents of the information container except for the count of connection failures.

2. The terminal according to claim 1, The information container includes connection failure report information and the PLMN identifier, and The connection failure report information includes a count of the connection failures.

3. The terminal according to claim 1, wherein in response to the failure of the RRC connection establishment process, the PLMN identifier and measurement result information about the cell in which the connection failure occurred are stored in the information container.

4. The terminal according to claim 3, wherein the measurement result information regarding the cell in which the connection failure occurred includes at least one of Global Cell Identifier, Reference Signal Received Power (RSRP), or Reference Signal Received Quality (RSRQ).

5. The terminal according to claim 1, wherein the connection failure information includes at least one of connection establishment failure information or connection recovery failure information.

6. The terminal according to claim 1, wherein the at least one processor is further configured to: In idle mode, an RRC establishment request message is sent to the base station (BS), or in inactive mode, an RRC recovery request message is sent. Receive RRC establishment message from the BS Enter connection mode. The terminal is identified to have available connection failure information in the information container, and the registered PLMN corresponds to the PLMN identifier included in the information container. Send an RRC establishment complete message to the BS, including a first indicator indicating that the terminal has available connection failure information. The BS receives a terminal information request message including a second indicator for reporting connection failure information, and When the second indicator is set to true, a terminal information response message including connection failure report information is sent to the BS, the connection failure report information including a count of the connection failures.

7. The terminal according to claim 6, wherein the at least one processor is further configured to discard connection failure report information included in the information container after confirming that the terminal information response message has been sent.

8. The terminal according to claim 1, wherein the at least one processor is further configured to: Select a PLMN from one or more PLMNs included in the PLMN identifier list in the system information, and The second PLMN identifier corresponding to the selected PLMN is stored in the information container.

9. The terminal according to claim 1, wherein the at least one processor is further configured to: Determine whether the second PLMN identifier of the registered PLMN is included in the information container, and If the second PLMN identifier of the registered PLMN is not included in the information container, a PLMN is selected from one or more PLMNs included in the PLMN identifier list in the system information, and the second PLMN identifier corresponding to the selected PLMN is stored in the information container.

10. The terminal of claim 1, wherein the at least one processor is further configured to store a second PLMN identifier corresponding to the registered PLMN in the information container in an inactive mode without PLMN selection.

11. A method for transmitting a signal, performed by a terminal in a wireless communication system, the method comprising: Start a timer when initiating the Radio Resource Control (RRC) connection establishment process; If the timer expires, it is determined whether at least one of the first or second conditions is met. The first condition includes the condition that the terminal has available connection failure information in the information container and the registered public land mobile network (PLMN) is not equal to the PLMN identifier included in the information container. The second condition includes the condition that the current cell is not equal to the cell in which the connection failure occurred. If at least one of the first or second conditions is met, the count of connection failures included in the information container will be set to 0; as well as After determining whether at least one of the first or second conditions is met, clear the contents of the information container except for the count of connection failures.

12. The method according to claim 11, The information container includes connection failure report information and the PLMN identifier, and The connection failure report information includes a count of the connection failures.

13. The method of claim 11, wherein in response to a failure of the RRC connection establishment process, the PLMN identifier and measurement result information about the cell in which the connection failure occurred are stored in the information container.

14. The method of claim 13, wherein the measurement information regarding the cell in which the connection failure occurred includes at least one of Global Cell Identifier, Reference Received Power (RSRP), or Reference Received Quality (RSRQ).

15. The method of claim 11, wherein the connection failure information includes at least one of connection establishment failure information or connection recovery failure information.

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