Method and apparatus for updating random access reporting in wireless mobile communications

Abstract

This disclosure relates to communication technologies and systems for the convergence of Internet of Things (IoT) technologies with 5th generation (5G) communication systems that support higher data transmission rates than 4th generation (4G) systems. This disclosure can be applied to smart services based on 5G communication systems and IoT-related technologies (e.g., smart or connected cars, healthcare, digital education, retail, security and safety-related services, etc.). Methods and apparatus for updating random access reports in wireless mobile communications are also provided.

Description

Technical Field

[0001] This disclosure relates to the operation of terminals and base stations in wireless communication systems. More specifically, this disclosure relates to methods and apparatus for random access reporting in wireless communication systems. Background Technology

[0002] To meet the increased demand for wireless data services resulting from the deployment of fourth-generation (4G) communication systems, efforts are underway to develop improved fifth-generation (5G) or pre-5G communication systems. Therefore, 5G or pre-5G communication systems are also referred to as "super-4G networks" or "post-LTE systems." The implementation of 5G communication systems at higher frequencies (millimeter-wave (mmWave) bands, such as the 60 GHz band, is being considered to achieve higher data rates. To reduce radio wave propagation losses and increase transmission distance, beamforming, massive MIMO, full-dimensional MIMO (FD-MIMO), array antennas, analog beamforming, and massive MIMO technologies are discussed in 5G communication systems. Furthermore, in 5G communication systems, development is underway to improve system networks based on advanced small cells, cloud radio access networks (RAN), ultra-density networks, device-to-device (D2D) communication, wireless backhaul, mobile networks, cooperative communication, cooperative multipoint (CoMP), and receiver interference cancellation. In 5G systems, hybrid frequency shift keying (FSK), quadrature amplitude modulation (QAM) (FQAM), and sliding window superposition coding (SWSC) have been developed as advanced coding and modulation (ACM), as well as filter bank multicarrier (FBMC), non-orthogonal multiple access (NOMA), and sparse code multiple access (SCMA) as advanced access technologies.

[0003] The Internet (a human-centric network of connectivity where humans generate and consume information) has now evolved into the Internet of Things (IoT), in which distributed entities, such as things, exchange and process information without human intervention. The Internet of Everything (IoE) has emerged, a combination of IoT technologies and big data processing technologies made through connectivity utilizing cloud servers. With the technological elements already required for IoT implementation, such as sensing technology, wired / wireless communication and network infrastructure, service interface technology, and security technology, recent research has focused on sensor networks, machine-to-machine (M2M) communication, and machine-type communication (MTC). Such an IoT environment can provide intelligent Internet technology services that create new value for human life by collecting and analyzing data generated in connected objects. Through the convergence and combination of existing information technology (IT) and various industrial applications, IoT can be applied to a wide range of fields, including smart homes, smart buildings, smart cities, smart or connected cars, smart grids, healthcare, smart appliances, and advanced medical services.

[0004] Accordingly, various attempts have been made to apply 5G communication systems to IoT networks. For example, technologies such as sensor networks, machine-type communication (MTC), and machine-to-machine (M2M) communication can be implemented through beamforming, MIMO, and array antennas. The application of cloud radio access networks (RAN), which are big data processing technologies described above, can also be considered as an example of the integration of 5G and IoT technologies.

[0005] The advancements in wireless communication systems described above enable the provision of various services, thus necessitating efficient solutions for delivering these services. More specifically, various methods for efficient handover processes are provided.

[0006] The above information is presented merely as background information to aid in understanding this disclosure. No determination or assertion is made as to whether any of the above is applicable as prior art with respect to this disclosure. Summary of the Invention

[0007] Technical issues

[0008] The aspects of this disclosure will at least address the aforementioned problems and / or disadvantages and provide at least the advantages described below. Therefore, the aspects of this disclosure provide methods and apparatus relating to Random Access Channel (RACH) report generation and VarRACH-report management operations to efficiently perform random access reporting in a mobile communication system.

[0009] Solution to the problem

[0010] In one embodiment, a method performed by a terminal in a wireless communication system includes: performing a random access procedure with a base station; clearing the first information associated with the Public Land Mobile Network (PLMN) and the second information associated with random access if the first information associated with the PLMN does not include PLMN information associated with the PLMN registered in the terminal; and storing reporting information associated with random access.

[0011] In another embodiment, a terminal in a wireless communication system includes: a transceiver; and at least one processor configured to: perform a random access procedure with a base station; clear the first information associated with the Public Land Mobile Network (PLMN) and the second information associated with random access if the first information associated with the PLMN does not include PLMN information associated with the PLMN registered in the terminal; and store reporting information associated with random access.

[0012] Beneficial effects of the present invention

[0013] Another aspect of this disclosure is to provide methods and apparatus related to RACH report generation and VarRACH-report management operations, so as to efficiently perform random access reporting in wireless communication systems. Attached Figure Description

[0014] The above and other aspects, features, and advantages of certain embodiments of this disclosure will become more apparent from the following description taken in conjunction with the accompanying drawings, in which:

[0015] Figure 1 The diagram illustrates the structure of a Long Term Evolution (LTE) system according to embodiments of the present disclosure;

[0016] Figure 2 This illustrates a wireless protocol structure in an LTE system according to an embodiment of the present disclosure;

[0017] Figure 3 The diagram illustrates the structure of a next-generation mobile communication system according to embodiments of the present disclosure;

[0018] Figure 4 This illustrates a wireless protocol structure in a next-generation mobile communication system according to embodiments of the present disclosure;

[0019] Figure 5 The internal structure of a terminal in a wireless communication system according to an embodiment of the present disclosure is shown;

[0020] Figure 6 This is a block diagram illustrating the configuration of a new radio (NR) base station in a wireless communication system according to an embodiment of the present disclosure;

[0021] Figure 7 The diagram illustrates a sequence of terminal and base station operations in a wireless communication system for transmitting a Random Access Channel (RACH) report, according to embodiments of the present disclosure.

[0022] Figure 8 This illustration shows a sequence of terminal operations in a wireless communication system for transmitting a delay report related to a RACH report, according to embodiments of the present disclosure.

[0023] Figure 9 This illustration shows a sequence of terminal operations in a wireless communication system for generating RACH reports and managing related VarRACH-report variables, according to embodiments of the present disclosure.

[0024] Figure 10 This illustration shows a sequence of terminal operations in a wireless communication system for generating RACH reports and managing related VarRACH-report variables, according to embodiments of the present disclosure.

[0025] Figure 11 This illustration shows a sequence of terminal operations in a wireless communication system for transmitting all RACH reports stored in variables related to RACH report transmission, according to embodiments of the present disclosure.

[0026] Figure 12 This illustration shows a sequence of terminal operations in a wireless communication system for transmitting a portion of a RACH report stored in variables related to RACH report transmission, according to embodiments of the present disclosure.

[0027] Figure 13a This illustrates a sequence of terminal operations related to RACH reporting in a wireless communication system according to embodiments of the present disclosure;

[0028] Figure 13b This illustrates a sequence of terminal operations related to RACH reporting in a wireless communication system according to an embodiment of the present disclosure.

[0029] Throughout 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

[0030] The following description, provided with reference to the accompanying drawings, is intended to aid in a comprehensive 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 will be considered merely exemplary. 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, descriptions of well-known functions may be omitted for clarity and conciseness.

[0031] The terminology and wording used in the following description and claims are not limited to their literal meaning, but are merely used by the inventors to achieve a clear and consistent understanding of this disclosure. Therefore, it should be apparent to those skilled in the art that the following description of various embodiments of this disclosure is for illustrative purposes only and is not intended to limit the disclosure as defined by the appended claims and their equivalents.

[0032] It should be understood that the singular forms “a” and “the” include plural indicators unless the context clearly indicates otherwise. Thus, for example, a reference to “component surface” includes a reference to one or more such surfaces.

[0033] Here it will be understood that each block of the flowchart illustration, and combinations of blocks in the flowchart illustration, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, or other programmable data processing device to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing device, produce means for implementing the functions specified in one or more flowchart blocks. These computer program instructions can also be stored in a computer-usable or computer-readable storage medium that can direct the computer or other programmable data processing device to operate in a particular manner, such that the instructions stored in the computer-usable or computer-readable storage medium produce an article of manufacture including instruction means for implementing the functions specified in one or more flowchart blocks. The computer program instructions can also be loaded onto a computer or other programmable data processing device to cause a series of operations to be performed on the computer or other programmable device to produce a computer-implemented process, such that the instructions, which execute on the computer or other programmable device, provide operations for implementing the functions specified in one or more flowchart blocks.

[0034] Furthermore, each block in the flowchart may represent a module, a fragment or section of code, which includes one or more executable instructions that implement a specified logical function(s). It should also be noted that in some alternative implementations, the functions indicated in a block may occur out of order. For example, depending on the functions involved, two blocks shown consecutively may actually be executed substantially in parallel, or sometimes the blocks may be executed in reverse order.

[0035] As used herein, "cell" refers to a software element or hardware element, such as a field-programmable gate array (FPGA) or application-specific integrated circuit (ASIC) that performs a predetermined function. However, "cell" does not always have a meaning limited to software or hardware. A "cell" can be configured to be stored in addressable storage media or to execute one or more processors. Thus, a "cell" includes, for example, software elements, object-oriented software elements, class elements or task elements, processes, functions, attributes, procedures, subroutines, fragments of program code, drivers, firmware, microcode, circuits, data, databases, data structures, tables, arrays, and parameters. Elements and functions provided by a "cell" can be combined into a smaller number of elements or "cells," or divided into a larger number of elements or "cells." Moreover, elements and "cells" can be implemented as one or more central processing units (CPUs) within a playback device or a secure multimedia card. Additionally, a "cell" in an embodiment may include one or more processors.

[0036] In the following description, for convenience, terms relating to access nodes, network entities, messages, interfaces between network entities, various identification information, etc., are used illustratively. Therefore, this disclosure is not limited to the terms used as follows, and other terms relating to subjects with equivalent technical meanings may be used. For example, in the following description, the term "terminal" may refer to the Media Access Control (MAC) entity in each terminal present for each of the Primary Cell Group (MCG) and the Secondary Cell Group (SCG).

[0037] In the following description, the terms and names defined in the 3GPP LTE standard will be used to describe this disclosure. However, this disclosure is not limited to these terms and names and can be applied in the same manner to systems conforming to other standards.

[0038] In the following description, a base station is an entity that allocates resources to terminals and can be at least one of a next-generation node B (gNode B), an evolved node B (eNode B), a node B, a base station (BS), a radio access unit, a base station controller, and a node on a network. Terminals can include user equipment (UE), mobile stations (MS), cellular phones, smartphones, computers, or multimedia systems capable of performing communication functions. Examples of base stations and terminals are not limited to these.

[0039] More specifically, this disclosure can be applied to 3GPP NR (5th generation mobile communication standard). Furthermore, this disclosure can be applied to smart services (e.g., smart homes, smart buildings, smart cities, smart cars or connected cars, healthcare, digital education, retail, security and safety-related services, etc.) based on 5G communication technology and IoT-related technologies. In this disclosure, "gNB" can be used interchangeably with the term "eNB". For example, a base station described as "eNB" can refer to "gNB". Additionally, the term "terminal" can refer to cellular phones, NB-IoT devices, sensors, and other wireless communication devices.

[0040] Wireless communication systems have expanded beyond their initial function of providing voice location services and have evolved into broadband wireless communication systems that provide high-speed and high-quality packet data services according to communication standards such as High Speed ​​Packet Access (HSPA), Long Term Evolution (LTE or Evolved Universal Terrestrial Radio Access (E-UTRA)), 3GPP Advanced LTE (LTE-A) and LTE-Pro, 3GPP2 High Speed ​​Packet Data (HRPD) and Ultra Mobile Broadband (UMB), and IEEE 802.16e.

[0041] As a representative example of a broadband wireless communication system, LTE systems employ Orthogonal Frequency Division Multiplexing (OFDM) for the downlink (DL) and Single-Carrier Frequency Division Multiple Access (SC-FDMA) for the uplink (UL). The uplink refers to the radio link that transmits data or control signals from a terminal (User Equipment (UE), Mobile Station (MS), or terminal) to a base station (eNodeB or Base Station (BS)), while the downlink refers to the radio link that transmits data or control signals from the base station to the terminal. In the aforementioned multiple access schemes, data or control information is typically differentiated based on the user by allocating or managing time and frequency resources used to carry each user's data or control information. These time and frequency resources do not overlap, i.e., orthogonality is established.

[0042] Future communication systems following LTE (i.e., 5G communication systems) must be able to freely respond to various demands from users, service providers, and others, and therefore need to support services that meet all these diverse demands. Services considered for 5G communication systems include enhanced mobile broadband (eMBB), massive machine-type communications (mMTC), and ultra-reliable low-latency communications (URLLC), among others.

[0043] According to embodiments of this disclosure, eMBB aims to provide data rates exceeding those supported by existing LTE, LTE-A, or LTE-Pro systems. For example, in a 5G communication system, from the perspective of a base station, eMBB should 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 should be able to provide not only peak data rates but also increased user-perceived terminal data rates. To meet this requirement, various improvements to transmission and reception technologies may be needed in 5G communication systems, including further improvements to multiple-input multiple-output (MIMO) transmission technology. Additionally, while current LTE uses a transmission bandwidth of up to 20 MHz in the 2 GHz band for signal transmission, 5G communication systems use bandwidths wider than 20 MHz in the 3 GHz to 6 GHz or 6 GHz or higher bands, thus meeting the data rates required in 5G communication systems.

[0044] In addition, mMTC is considering supporting application services such as the Internet of Things (IoT) in 5G communication systems. mMTC may need to support access from a large number of terminals within a cell, enhanced terminal coverage, improved battery life, and reduced terminal costs to efficiently deliver IoT. IoT needs to be able to support a large number of terminals within a cell (e.g., 1,000,000 terminals / km). 2 This is because it is attached to various sensors and devices that provide communication capabilities. Additionally, mMTC-enabled terminals are likely to be located in obstructed areas (such as building basements) that are not covered by the cell due to the nature of the service, and therefore require wider coverage than other services offered in 5G communication systems. mMTC-enabled terminals need to be configured as inexpensive devices and may require very long battery life, such as 10 to 15 years, due to the difficulty of frequently replacing the terminal's battery.

[0045] Finally, URLLC is a cellular-based wireless communication service for mission-critical purposes and can be applied to services such as remote control of robots or machinery, industrial automation, unmanned aerial vehicles, remote healthcare, and emergency alerts. Therefore, communication provided via URLLC can offer very low latency (ultra-low latency) and very high reliability (ultra-high reliability). For example, URLLC-enabled services need to meet air interface latency requirements of less than 0.5 milliseconds and can also have packet error rates of 5-10% or lower. Therefore, for URLLC-enabled services, 5G systems need to provide shorter Transmission Time Intervals (TTIs) than those other services, and there may also be design challenges related to allocating wider bandwidth resources to ensure the reliability of communication lines.

[0046] The three services mentioned above—eMBB, URLLC, and mMTC—considered in 5G communication systems can be multiplexed and transmitted within a single system. Here, to meet the different requirements of each service, different transmission or reception schemes and different transmission and reception variables can be used for the services. However, mMTC, URLLC, and eMBB described above are merely examples of different types of services, and the types of services to be applied according to this disclosure are not limited to the examples described above.

[0047] Furthermore, the embodiments of this disclosure will be described below using LTE, LTE-A, LTE-Pro, or 5G (or NR, i.e., next-generation mobile communication) systems as examples. However, the embodiments of this disclosure can be applied to other communication systems with similar technical backgrounds or channel configurations. Moreover, with some modifications, it will be determined by those skilled in the art that the embodiments of this disclosure can be applied to other communication systems with some modifications without significantly departing from the scope of this disclosure.

[0048] This disclosure relates to condition switching, and embodiments of this disclosure provide a method for executing signals according to switching conditions in a dual-connectivity system, as well as related equipment.

[0049] According to embodiments of this disclosure, when a terminal changes its primary / secondary cell (PSCell) in a New Radio Dual Connectivity (NR-DC) scenario, the network can send specific conditions to the terminal in advance. Furthermore, when the specific conditions are met, the terminal that received the specific conditions can perform a conditional handover.

[0050] Furthermore, according to embodiments of this disclosure, when a terminal fails to perform a conditional handover, a network-related signaling system can be proposed to enable the terminal to quickly handover to another cell.

[0051] Furthermore, according to the disclosed embodiments, in a terminal configured with dual connectivity, if the terminal changes the PSCell, a signaling system between nodes required when conditions related to condition switching are sent to the terminal can be proposed. Additionally, if the terminal configured with dual connectivity fails to change the PSCell, subsequent operations required by the terminal can be proposed.

[0052] Furthermore, according to embodiments of this disclosure, the terminal can change the PSCell of the secondary node without errors.

[0053] This disclosure addresses at least the aforementioned problems and / or disadvantages and provides at least the advantages described below. Therefore, this disclosure provides methods and apparatus relating to Random Access Channel (RACH) report generation and VarRACH-report management operations to efficiently perform random access reporting in a mobile communication system.

[0054] Another aspect of this disclosure is to provide methods and apparatus related to RACH report generation and VarRACH-report management operations, so as to efficiently perform random access reporting in wireless communication systems.

[0055] Additional aspects will be set forth in part in the following description, and will be partially obvious from the description, or may be learned by practice of the presented embodiments.

[0056] Other aspects, advantages, and notable features of this disclosure will become apparent to those skilled in the art from the following detailed description of various embodiments thereof, taken in conjunction with the accompanying drawings.

[0057] Figure 1 The structure of an LTE system according to an embodiment of the present disclosure is shown.

[0058] refer to Figure 1 The radio access network of an LTE system may include next-generation base stations (evolved Node Bs, hereinafter referred to as "ENB", "Node B", or "base station") 105, 110, 115, and 120, a Mobility Management Entity (MME) 125, and a Service Gateway (S-GW) 130. User equipment (hereinafter referred to as "UE" or "terminal") 135 can access external networks through ENBs 105 to 120 and S-GW 130.

[0059] exist Figure 1In this context, ENBs 105 to 120 can correspond to existing nodes (Bs) in a Universal Mobile Telecommunications System (UMTS). The ENB can connect to the UE 135 via a radio channel and can perform more complex functions compared to existing nodes (Bs). In LTE systems, all user services, including real-time services such as Internet Protocol Telephony (VoIP), can be served through shared channels. Therefore, it is necessary to have means for collecting state information such as the UE's buffer state information, the UE's available transmission power state information, and the UE's channel state information, and to perform scheduling, and each of ENBs 105 to 120 can serve as such means. A single ENB can control multiple cells overall. For example, an LTE system uses radio access technologies such as Orthogonal Frequency Division Multiplexing (OFDM) in a 20MHz bandwidth to achieve a data rate of 100Mbps. Additionally, the ENB can also apply Adaptive Modulation & Coding (AMC) strategies to determine the modulation strategy and channel coding rate based on the terminal's channel state. The S-GW 130 is a means for providing data bearers and can generate or release data bearers under the control of the MME 125. An MME is a device used to perform mobility management functions and various control functions for a terminal, and can be connected to multiple base stations.

[0060] Figure 2 The wireless protocol structure in an LTE system according to an embodiment of the present disclosure is shown.

[0061] refer to Figure 2 The radio protocols in an LTE system include Packet Data Convergence Protocol (PDCP) 205 and 240, Radio Link Control (RLC) 210 and 235, Media Access Control (MAC) 215 and 230, and physical (PHY) devices in the terminal and ENB respectively. PDCP can perform operations such as IP header compression / reconstruction. The main functions of PDCP are summarized below, but are not limited to:

[0062] - Header compression and decompression: Robust header compression only (ROHC)

[0063] -Transmission of user data

[0064] - Sequential transmission of upper-layer protocol data units (PDUs) during the PDCP reconstruction process for RLC acknowledgment mode (AM).

[0065] - For split bearers in the DC (RLC AM only): PDCP PDU routing for transmission and PDCP PDU reordering for reception.

[0066] - Repeated detection of the lower-level SDU in the PDCP reconstruction process for RLC AM

[0067] - Retransmission of PDCP SDUs during handover, and retransmission of PDCP PDUs during PDCP data recovery of separated bearers in RLC AM in DC.

[0068] - Encryption and decryption

[0069] - Timer-based Service Data Units (SDUs) in the uplink are dropped.

[0070] According to embodiments of this disclosure, Radio Link Control (RLC) 210 and 235 can reconfigure PDCP Protocol Data Units (PDUs) at appropriate sizes to perform Automatic Repeat Request (ARQ) operations, etc. The main functions of the RLC are summarized below, but are not limited thereto:

[0071] -Transmission of upper-layer PDUs

[0072] - Error correction via ARQ (for AM data transmission only)

[0073] - Cascading, segmentation, and reassembly of RLC SDUs (for Negative Acknowledgment Mode (UM) and AM data transmission only)

[0074] - Resegmentation of RLC data PDUs (for AM data transmission only)

[0075] - Reordering of RLC data PDUs (for UM and AM data transfer only)

[0076] - Duplicate detection (only for UM and AM data transfers)

[0077] - Protocol error detection (for AM data transmission only)

[0078] -RLC SDU discard (only for UM and AM data transfers)

[0079] -RLC reconstruction.

[0080] According to embodiments of this disclosure, MACs 215 and 230 are connected to a plurality of RLC layer devices configured in a terminal, and can perform operations of multiplexing RLC PDUs into and demultiplexing RLC PDUs from the MAC PDUs. The main functions of the MAC are summarized below, but are not limited thereto:

[0081] - Mapping between logical channels and transmission channels

[0082] - Multiplexing MAC SDUs belonging to one or different logical channels into a transport block (TB) / demultiplexing MAC SDUs belonging to one or different logical channels from a transport block (TB), which is passed to the physical layer on the transport channel / passed from the physical layer.

[0083] - Scheduling Information Report

[0084] - Error correction via Hybrid ARQ (HARQ)

[0085] Priority processing between logical channels of a UE

[0086] - Prioritization among UEs is performed through dynamic scheduling.

[0087] - Multimedia Broadcast Multicast Service (MBMS) Service Identification

[0088] -Transmission format selection

[0089] -filling

[0090] According to embodiments of this disclosure, physical layers (PHYs) 220 and 225 can generate OFDM symbols by performing channel coding and modulation on upper-layer data and transmitting them via a wireless channel, or they can perform demodulation and channel decoding on OFDM symbols received via a wireless channel and transmit them to the upper layer.

[0091] Figure 3 The structure of a next-generation mobile communication system according to an embodiment of the present disclosure is shown.

[0092] refer to Figure 3 The radio access network in a next-generation mobile communication system (hereinafter referred to as "New Radio (NR)" or 5G) may include a new radio base station (new radio node B, hereinafter referred to as "NR gNB" or "NR base station") 310 and a new radio core network (NR CN) 305. New radio user equipment (hereinafter referred to as "NR UE" or "NR terminal") 315 can access external networks through the NR gNB 310 and NR CN 305.

[0093] exist Figure 3In this context, the NR gNB 310 corresponds to the evolved Node B (eNB) in an existing LTE system. The NR gNB 310 can connect to the NR UE 315 via a radio channel and thus can provide services superior to those of the existing Node B. In next-generation mobile communication systems, services are provided to all user services through a shared channel. Therefore, there is a need for means to collect state information such as the UE's buffer state information, the UE's available transmission power state information, and the UE's channel state information, and to perform scheduling; the NR gNB 310 can serve as such a means. A single NR gNB 310 can control multiple cells overall. To achieve ultra-high-speed data transmission in next-generation mobile communication systems compared to existing LTE, a bandwidth equal to or greater than the existing maximum bandwidth can be applied. Additionally, orthogonal frequency division multiplexing (OFDM) combined with beamforming technology can be used as the radio connectivity technology.

[0094] Additionally, an adaptive modulation and coding (AMC) strategy can be applied to determine the modulation strategy and channel coding rate based on the terminal's channel state. The NR CN 305 can perform functions such as mobility support, bearer configuration, and quality of service (QoS) configuration. The NR CN 305 is a device that performs not only terminal mobility management functions but also various types of control functions and can connect to multiple base stations. Furthermore, next-generation mobile communication systems can link with existing LTE systems, and the NR CN 305 can connect to the MME 325 via a network interface. The MME 325 connects to the eNB 330, which serves as an existing base station.

[0095] Figure 4 This illustration shows a wireless protocol structure in a next-generation mobile communication system according to an embodiment of the present disclosure.

[0096] refer to Figure 4 In the wireless protocols of next-generation mobile communication systems, terminals and NR base stations may include NR Service Data Adaptation Protocol (SDAP) 401 and 445, NR PDCP 405 and 440, NR RLC 410 and 435, NR MAC 415 and 430, and NR PHY devices (or layers) 420 and 425, respectively.

[0097] According to embodiments of this disclosure, the main functions of NR SDAP 401 and 445 may include some of the following functions, but are not limited thereto:

[0098] -Transmission of user plane data

[0099] - Mapping between QoS flows and Data Radio Bearers (DRBs) for both DL and UL

[0100] - Mark the QoS flow identifier (ID) in both DL and UL packets.

[0101] - Mapping of reflective QoS flows to DRB for UL SDAP PDU.

[0102] For SDAP layer devices, a terminal can receive headers via Radio Resource Control (RRC) messages regarding whether to use the SDAP layer device or configurations for whether to use SDAP layer device functionality for each PDCP layer device, each bearer, or each logical channel. When the SDAP header is configured, the terminal can be instructed to update or reconfigure the mapping information for uplink and downlink QoS flows and data bearers using the Non-Access Stratum (NAS) reflective QoS 1-bit indicator and the Access Stratum (AS) reflective QoS 1-bit indicator in the SDAP header. According to embodiments of this disclosure, the SDAP header may include QoS flow ID information indicating QoS. According to embodiments of this disclosure, QoS information can be used as data processing priority, scheduling information, etc., to support smooth service.

[0103] According to embodiments of this disclosure, the main functions of NR PDCP 405 and 440 may include some of the following functions, but are not limited thereto:

[0104] -Header compression and decompression: ROHC only

[0105] -Transmission of user data

[0106] - Sequential transmission of upper-layer PDUs

[0107] -Disordered transmission of upper-layer PDUs

[0108] - Reordering received PDCP PDUs

[0109] -Duplicate detection of lower-level SDUs

[0110] -PDCP SDU retransmission

[0111] - Encryption and decryption

[0112] - Timer-based SDU dropping in the uplink.

[0113] In the above description, the reordering function of an NR PDCP device can refer to the function of rearranging PDCP PDUs received in the lower layer according to the PDCP sequence number (SN). The reordering function of an NR PDCP device may include the function of transmitting data to the upper layer in the rearranged order, the function of transmitting data directly without considering the order, the function of recording lost PDCP PDUs by rearranging the order, the function of reporting the status of lost PDCP PDUs to the sender, and the function of requesting retransmission of lost PDCP PDUs.

[0114] According to embodiments of this disclosure, the main functions of NR RLC 410 and 435 may include some of the following functions, but are not limited thereto:

[0115] -Transmission of upper-layer PDUs

[0116] - Sequential transmission of upper-layer PDUs

[0117] -Disordered transmission of upper-layer PDUs

[0118] - Error correction via ARQ

[0119] Cascading, segmentation, and reassembly of RLC SDUs

[0120] - Resegmentation of RLC data PDUs

[0121] - Reordering of RLC data PDUs

[0122] -Duplicate detection

[0123] -Protocol error detection

[0124] -RLC SDU discard

[0125] -RLC reconstruction.

[0126] In the above description, the sequential delivery function of an NR RLC device can refer to the function of sequentially transmitting RLC SDUs received from a lower layer to an upper layer. When a single RLC SDU is divided into multiple RLC SDUs and the multiple RLC SDUs are received, the sequential delivery function of an NR RLC device can include the function of rearranging and transmitting them.

[0127] The sequential transmission function of the NR RLC device may include: the function of rearranging the received RLC PDUs based on the RLC sequence number (SN) or PDCP sequence number (SN); the function of recording lost RLC PDUs by rearranging the order; the function of reporting the status of lost RLC PDUs to the sender; and the function of requesting the retransmission of lost RLC PDUs.

[0128] When a lost RLC SDU exists, the sequential delivery function of the NR RLC device may include the function of sequentially delivering only the RLC SDUs preceding the lost RLCSDU to the upper layer.

[0129] When a lost RLC SDU exists, but the scheduled timer terminates, the sequential delivery function of the NR RLC device can include the ability to sequentially deliver all RLC SDUs received before the timer starts to the upper layer.

[0130] When a lost RLC SDU exists, but the predetermined timer terminates, the sequential delivery function of the NR RLC device may include the function of transmitting all RLC SDUs received up to that point in time to the upper layer.

[0131] The NR RLC device can process RLC PDUs in the order they are received, regardless of the sequence number or order number, and can pass the processed RLC PDUs to the NR PDCP device.

[0132] When the NR RLC device receives a segment, the NR RLC can receive the segment stored in the buffer or to be received later, reconfigure the segment into a complete RLC PDU, and then pass it to the NR PDCP device.

[0133] The NR RLC layer may not include cascading functionality and may perform the functions in the NR MAC layer, or may replace the functions with multiplexed functions of the NR MAC layer.

[0134] In the above description, the out-of-order delivery function of an NR RLC device can refer to the function of directly delivering RLC SDUs received from a lower layer to the upper layer regardless of the order. When a single RLC SDU is divided into multiple RLC SDUs and the multiple RLC SDUs are received, the out-of-order delivery function of the NR RLC device can include the function of rearranging and transmitting the multiple RLC SDUs. The out-of-order delivery function of the NR RLC device can include: storing the PDCP SN or RLC SN of each of the received RLC PDUs, arranging the RLC PDUs, and recording lost RLC PDUs.

[0135] According to embodiments of this disclosure, NR MACs 415 and 430 can be connected to several NRRLC layer devices configured in a terminal, and the main functions of the MACs can include, but are not limited to, some of the following:

[0136] - Mapping between logical channels and transmission channels

[0137] - MAC SDU multiplexing / demultiplexing

[0138] - Scheduling Information Report

[0139] - Error correction via HARQ

[0140] Priority processing between logical channels of a UE

[0141] - Prioritization among UEs is performed through dynamic scheduling.

[0142] -MBMS service identifier

[0143] -Transmission format selection

[0144] -filling

[0145] The NR physical layer (NR PHY) 420 and 425 can generate OFDM symbols by performing channel coding and modulating upper-layer data, and transmit them over a wireless channel, or they can perform demodulation and channel decoding on OFDM symbols received over a wireless channel and transmit them to the upper layer.

[0146] Figure 5 The internal structure of a terminal in a wireless communication system according to an embodiment of the present disclosure is shown.

[0147] refer to Figure 5 The terminal may include, but is not limited to, a radio frequency (RF) processor 510, a baseband processor 520, a storage device 530, and a controller 540 including a multi-connection processor 542, and may include, with Figure 5 It can show a relatively small configuration or may include more configurations.

[0148] RF processor 510 can perform functions such as transmitting or receiving signals via a wireless channel, including signal band conversion and amplification. For example, RF processor 510 can upsample a baseband signal provided by baseband processor 520 into an RF band signal, and then transmit the RF band signal through an antenna, and downsample the RF band signal received through the antenna back into a baseband signal. RF processor 510 may include, but is not limited to, transmit filters, receive filters, amplifiers, mixers, oscillators, digital-to-analog converters (DACs), analog-to-digital converters (ADCs), etc. Although... Figure 5 Only a single antenna is shown, but the terminal may include multiple antennas. Additionally, the RF processor 510 may include multiple RF chains. Furthermore, the RF processor 510 can perform beamforming. For beamforming, the RF processor 510 can adjust the phase and amplitude of signals transmitted or received through multiple antennas or antenna elements. The RF processor 510 can also perform MIMO and can receive data from multiple data layers during MIMO operation.

[0149] The baseband processor 520 performs the function of converting between baseband signals and bitstreams according to the physical layer specifications of the system. For example, during data transmission, the baseband processor 520 generates composite symbols by encoding and modulating the transmitted bitstream. Furthermore, during data reception, the baseband processor 520 can reconstruct the received bitstream by demodulating and decoding the baseband signal provided from the RF processor 510. For example, according to an Orthogonal Frequency Division Multiplexing (OFDM) scheme, during data transmission, the baseband processor 520 generates composite symbols by encoding and modulating the transmitted bitstream, maps the composite symbols to subcarriers, and then configures the OFDM symbols by performing an Inverse Fast Fourier Transform (IFFT) operation and cyclic prefix (CP) insertion. Furthermore, during data reception, the baseband processor 520 can segment the baseband signal provided from the RF processor 510 into units of OFDM symbols, reconstruct the signal mapped to the subcarriers by performing a Fast Fourier Transform (FFT) operation, and then reconstruct the received bitstream by demodulating and decoding the signal.

[0150] The baseband processor 520 and RF processor 510 transmit and receive signals as described above. Therefore, each of the baseband processor 520 and RF processor 510 can also be referred to as a transmitter, receiver, transceiver, or communication unit. Furthermore, at least one of the baseband processor 520 and RF processor 510 may include multiple communication modules supporting various different wireless access technologies. Additionally, at least one of the baseband processor 520 and RF processor 510 may include multiple communication modules that process signals in different frequency bands. For example, different wireless access technologies may include wireless local area networks (LANs) (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 NRHz, NRhz) and millimeter wave (mmWave) bands (e.g., 60 GHz). A terminal can transmit signals to or receive signals from a base station using the baseband processor 520 and RF processor 510, and the signals may include control information and data.

[0151] Storage device 530 stores data such as basic programs, applications, configuration information, etc., for the operation of the terminal. Specifically, storage device 530 may store information related to the second connection node for performing wireless communication using the second wireless connection technology. Additionally, storage device 530 provides the stored data in response to requests from controller 540. Storage device 530 may include storage media such as read-only memory (ROM), random access memory (RAM), hard disk, optical disc (CD)-ROM, and digital versatile disk (DVD), as well as combinations of storage media. Furthermore, storage device 530 may also include multiple memories.

[0152] Controller 540 controls the overall operation of the terminal. For example, controller 540 transmits or receives signals via baseband processor 520 and RF processor 510. Furthermore, controller 540 records data on and reads data from storage device 530. For this purpose, controller 540 may include at least one processor. For example, controller 540 may include a communication processor (CP) for controlling communications and an application processor (AP) for controlling upper-layer applications such as applications. At least one component of the terminal may be implemented in a single chip.

[0153] According to embodiments of this disclosure, controller 540 can control each element of the terminal to execute a switching method according to embodiments of this disclosure. The following will... Figures 7 to 10 The switching method described in this disclosure is described in the document.

[0154] Figure 6 This is a block diagram illustrating the configuration of an NR base station in a wireless communication system according to an embodiment of the present disclosure.

[0155] refer to Figure 6 The base station includes, but is not limited to, an RF processor 610, a baseband processor 620, a backhaul communication unit 630, a storage device 640, and a controller 650 including a multi-connection processor 652, and the terminal may include... Figure 6 It can show a relatively small configuration or may include more configurations.

[0156] RF processor 610 can perform functions such as transmitting or receiving signals via a wireless channel, including signal band conversion and amplification. For example, RF processor 610 can upsample a baseband signal provided by baseband processor 620 to an RF band signal, transmit the converted RF band signal via an antenna, and downsample a received RF band signal back to a baseband signal. RF processor 610 may include, for example, a transmit filter, receive filter, amplifier, mixer, oscillator, DAC, ADC, etc. Although in Figure 6Only a single antenna is shown, but the RF processor 610 may include multiple antennas. Additionally, the RF processor 610 may include multiple RF chains. Furthermore, the RF processor 610 can perform beamforming. For beamforming, the RF processor 610 can adjust the phase and amplitude of signals transmitted or received through multiple antennas or antenna elements. The RF processor 610 can perform downlink MIMO operation by transmitting data from one or more layers.

[0157] The baseband processor 620 can perform the conversion between baseband signals and bitstreams based on the physical layer specification of the first radio access technology. For example, during data transmission, the baseband processor 620 can generate composite symbols by encoding and modulating the transmitted bitstream. Furthermore, during data reception, the baseband processor 620 can reconstruct the received bitstream by demodulating and decoding the baseband signal provided from the RF processor 610. For example, according to an OFDM scheme, during data transmission, the baseband processor 620 generates composite symbols by encoding and modulating the transmitted bitstream, maps the composite symbols to subcarriers, and then configures the OFDM symbols by performing IFFT operations and CP insertion. Furthermore, during data reception, the baseband processor 620 can segment the baseband signal provided from the RF processor 610 into units of OFDM symbols, reconstruct the signal mapped to the subcarriers by performing FFT operations, and then reconstruct the received bitstream by demodulating and decoding the signal. The baseband processor 620 and the RF processor 610 can transmit and receive signals as described above. Therefore, each of the baseband processor 620 and the RF processor 610 can also be referred to as a transmitter, receiver, transceiver, communication unit, or wireless communication unit. A base station can transmit signals to or receive signals from a terminal using the baseband processor 620 and the RF processor 610, and the signals may include control information and data.

[0158] The backhaul communication unit 630 provides an interface for communicating with other nodes in the network. For example, the backhaul communication unit 630 can convert a bit stream sent from the primary base station to another node, such as a secondary base station, core network, etc., into a physical signal, and can convert a physical signal received from another node into a bit stream. The backhaul communication unit 630 may be included in a communication unit.

[0159] Storage device 640 stores data such as basic programs, applications, and configuration information used for the operation of the main base station. Storage device 640 can store information related to bearers allocated to connected terminals, measurement results reported from connected terminals, etc. Additionally, storage device 640 can store information used as criteria for determining whether to provide multiple connections to terminals. Furthermore, storage device 640 provides the stored data in response to requests from controller 650. Storage device 640 may include storage media such as ROM, RAM, hard disk, CD-ROM, and DVD, as well as combinations of storage media. Additionally, storage device 640 may include multiple memories.

[0160] The controller 650 controls the overall operation of the base station. For example, the controller 650 transmits or receives signals via the baseband processor 620 and the RF processor 610 or via the backhaul communication unit 630. Additionally, the controller 650 records data on and reads data from the storage device 640. For this purpose, the controller 650 may include at least one processor. Furthermore, at least one component of the base station may be implemented in a single chip.

[0161] Figure 7 The present disclosure illustrates a sequence of terminal and base station operations in a wireless communication system for transmitting a Random Access Channel (RACH) report, according to embodiments of the present disclosure.

[0162] refer to Figure 7 The radio access state of terminal 705 can be in RRC idle state or RRC inactive state, and then cell reselection can be performed for a specific base station 710. The radio access state of terminal 705 can be changed to RRC connected state by performing a connection operation in operation 715. In the connected mode state, in operation 720, the terminal can receive measurement configuration information from the base station. Therefore, the terminal can receive configuration information about uplink (UL) delay reports. When the configuration information is received, the terminal can measure the delay of the correspondingly configured data radio bearer (DRB) in operation 725, and can perform the operation of reporting the relevant measurement information to base station 710 in operation 728.

[0163] When terminal 705 lacks sufficient resources for uplink data transmission, or when terminal 705 has already received a random access command from the base station in operation 730, the terminal can perform random access in operation 735. Upon completion of the random access procedure, the terminal can generate a RACH report and update or modify the VarRACH-report variable in operation 740.

[0164] Base station 710 can request a RACH report from terminal 705 via a UEInformationRequest message in operation 745. When the message includes an indicator requesting a RACH report, in operation 750, the terminal can identify the currently stored VarRACH-report variable and refer to the RACH report information in the VarRACH-report variable to send a RACH report to the base station. In this case, the terminal can add the content to be sent to a UEInformationResponse message and send the message to the base station in operation 755.

[0165] Figure 8 This illustration shows a sequence of terminal operations in a wireless communication system for transmitting a delay report related to a RACH report, according to embodiments of the present disclosure.

[0166] When the terminal is Figure 7 When the terminal receives measurement configuration information related to uplink (UL) delay reports from the base station, it can receive configuration related to delay measurement in operation 720. In this case, the terminal can perform the following operations.

[0167] refer to Figure 8 The received measurement configuration information may include an uplink delay ratio configuration report indicator (UL-DelayRatioConfig). Additionally, the received measurement configuration information may include multiple DRB identifiers (DRB IDs) and uplink delay threshold information. Furthermore, in operation 805, the received measurement configuration information may include an uplink delay value configuration report indicator (UL-DelayValueConfig).

[0168] When the measurement configuration information includes an uplink delay ratio configuration report indicator or multiple DRB IDs and uplink delay threshold information, the terminal can specify the DRB by using the DRB ID included in the measurement configuration information. Furthermore, in operation 810, uplink delay (UL delay) measurement can be performed in the PDCP entity of the specified DRB.

[0169] When the terminal performs uplink delay measurement in the PDCP entity of the specified DRB, in operation 815, an uplink delay measurement report can be triggered when the following conditions are met.

[0170] In the following description, the ratio may refer to the ratio of the number of packets exceeding the delayThreshold value to the total number of packets generated. A ratio is considered available when it is equal to or greater than the uplink latency ratio included in the measurement configuration information. When this ratio is available, an uplink latency measurement report can be triggered.

[0171] Alternatively, the meaning of "ratio available" can refer to the situation where a ratio value is actually derived from the PDCP. A situation where a value can be derived from the PDCP can be represented as "available in the RRC".

[0172] The received measurement configuration information includes an uplink delay ratio configuration report indicator and the availability of all ratio values ​​for all IDs of the UL delay measurement (these DRBs are specified during measurement configuration). Specifically, all ratio values ​​(each indicating the ratio of the number of packets exceeding the delayThreshold value configured together during measurement configuration to the total number of generated packets) are available (i.e., the ratio value indicating the ratio of the number of packets at each DRB delay to the total number of generated packets).

[0173] The received measurement configuration information includes an uplink delay ratio configuration report indicator, and based on the UL delay measurement value, a representative value for the ratio of all IDs specified in the measurement configuration during DRB is available if it is available. That is, a representative value for the ratio indicating the ratio of the number of packets exceeding the delayThreshold value configured together in the measurement configuration to the total number of generated packets is available (where the representative ratio value may mean the average of the ratio values ​​that each indicates the ratio of the number of packets at each DRB delay to the total number of generated packets).

[0174] - The received measurement configuration information includes an uplink delay ratio configuration report indicator, and, based on the UL delay measurement value, the ratio value of at least one DRB specified during measurement configuration is available, i.e., the ratio of the number of packets exceeding the delayThreshold value configured together during measurement configuration to the total number of generated packets is available (i.e., the ratio value is generated in at least one DRB).

[0175] According to embodiments of this disclosure, in operation 805, the received measurement configuration information may have a UL delay ratio configuration report indicator.

[0176] When the received measurement configuration information includes multiple DRB IDs, the terminal can specify the DRB based on the DRB-ID included in the measurement configuration information. Additionally, in operation 810, the terminal can perform UL delay measurement in the PDCP entity of the specified DRB.

[0177] When a terminal performs a UL delay measurement in the PDCP entity of a specified DRB, a UL delay measurement report can be triggered if the following conditions are met.

[0178] In the following description, a delay value is considered available when the UL delay measurement is equal to or greater than the value configured according to the uplink delay value included in the measurement configuration information.

[0179] Alternatively, the availability of a delay value can mean the situation where the delay value is actually derived from the PDCP. A situation where a value can be derived from the PDCP can be represented as being available in the RRC.

[0180] The received measurement configuration information includes an uplink latency value configuration report indicator, and is based on the UL latency measurement value for all IDs specified during measurement configuration, with the latency value being available for each DRB.

[0181] The received measurement configuration information includes an uplink latency value configuration report indicator, and a representative latency value is available based on the UL latency measurement values ​​of the DRBs specified during measurement configuration for all IDs (wherein, the representative latency value may refer to the average latency value measured for each DRB).

[0182] In the above scenario, during operation 815, the terminal can generate a measurement report, include the corresponding delay ratio values ​​(multiple) or delay values ​​(multiple) in the measurement report, and send it to the base station.

[0183] Figure 9 This illustration shows a sequence of terminal operations in a wireless communication system for generating RACH reports and managing related VarRACH-report variables, according to embodiments of the present disclosure.

[0184] Once the terminal has completed random access with respect to the base station, it can generate a RACH report and update or manage the VarRACH-report variable.

[0185] refer to Figure 9 When a terminal has completed random access under Operation 905, it can generate a report related to the completed RACH. Each RACH report may include the following:

[0186] -RACH Purpose: This refers to the purpose for which the terminal performs random access. There are various situations in which a terminal performs random access. Due to insufficient uplink resources for Measurement Report (MR) transmission, or to acquire uplink resources for other purposes, the terminal may perform random access. In this case, the purpose value can be configured as "noPUCCHResourceAvailable". Alternatively, when the base station has already indicated random access to the terminal via the Physical Downlink Control Channel (PDCCH), the purpose value can be configured as "pdcchOrder". Alternatively, depending on the purpose of the purpose value, it can be configured based on the following: "accessRelated" for initial access, "beamFailureRecovery" for notifying the network of beam failures, "reconfigurationWithSync" and "ulUnSynchronized" for target cell access during handover, "schedulingRequestFailure" for notifying of scheduling request failures, "sCellAdditionTAAdjustment" for SCell addition and timing adjustments, and "requestForOtherSI" for requesting system information.

[0187] - Cell Identifier: This indicates the identifier of the cell in which the terminal has performed random access, and may include the cell identifier. The cell identifier may include the Public Land Mobile Network (PLMN) identifier of the cell in which RACH has been completed, as well as the corresponding cell identifier. A combination of the Physical Cell ID and the Base Station ID can be an example of a cell identifier. Alternatively, the cell identifier can be a specific identifier that can uniquely distinguish a cell within the PLMN. Additionally, the cell identifier may refer to the Cell Global Identifier (NR CGI).

[0188] -absoluteFrequencyPointA: This indicates the absolute frequency location information of the cell where random access was performed, and can be the absolute frequency location of a reference resource block.

[0189] -locationAndBandwidth: This is a value represented as an integer and can be the bandwidth of the frequency domain location and bandwidth portion associated with the random access resources used by the UE.

[0190] -subcarrierSpacing: This refers to the subcarrier spacing information used in the bandwidth portion (BWP) of random access already performed at the terminal.

[0191] -msg1-FrequencyStart: This is an integer value and can be the offset of the lowest Physical Random Access Channel (PRACH) transmission timing in the frequency domain relative to the Physical Resource Block (PRB) 0 of the UL BWP.

[0192] -msg1-SubcarrierSpacing: This refers to the subcarrier spacing of the PRACH resource information.

[0193] -perRACHInfoList: This refers to information representing detailed information about each trial during random access, in chronological order. This can represent detailed information about the reference signal considered at each trial. This field can include detailed information about consecutive random access trials using the same Continuous Synchronization Block (SSB) or Channel State Information Reference Signal (CSI-RS). The details include the number of preamble codes sent to the corresponding RS for each SSB or CSI-RS, whether contention occurred in each period when the preamble code was sent to the corresponding RS, and information indicating the downlink reference signal received power (RSRP) strength of the RS in the corresponding period.

[0194] The terminal can generate a RACH report in operation 910, or update or modify the VarRACH-Report described below in operation 920. When the Equivalent Public Land Mobile Network (EPLMN) list currently stored in the terminal is the same as the plmnIdentityList stored in the existing VarRACH-Report variable, or when the ELMN list currently stored in the terminal is included in the plmnIdentityList stored in the existing VarRACH-Report variable, the terminal can add the generated RACH-report to the existing RACH-ReportList stored in the VarRACH-Report report. Alternatively, the terminal may not change the plmnIdentityList of the VarRACH-Report variable.

[0195] When the EPLMN list currently stored in the terminal is different from the plmnIdentityList stored in the existing VarRACH-Report variable, or when the EPLMN list currently stored in the terminal is not included in the plmnIdentityList stored in the existing VarRACH-Report variable, the terminal can refresh all RACH-reports stored in the RACH-report list of the existing VarRACH-Report variable and re-add the most recent RACH report generated in operation 910 to the RACH-ReportList of the VarRACH-Report variable. Additionally, in operation 920, the terminal can replace the plmnIdentityList of VarRACH-Report with the EPLMN list currently stored in the terminal.

[0196] According to another embodiment of this disclosure, in operation 925, when a predetermined time has elapsed, the terminal can discard the RACH report generated based on each random access test from the VarRACH-Report list.

[0197] Figure 10 This illustration shows a sequence of terminal operations in a wireless communication system for generating RACH reports and managing related VarRACH-report variables, according to embodiments of the present disclosure.

[0198] Once the terminal has completed random access with respect to the base station, it can generate a RACH report and update or manage the VarRACH-report variable.

[0199] refer to Figure 10 When a terminal has completed random access in Operation 1005, the terminal can generate a report related to the completed RACH. Each RACH report may include the following content.

[0200] -RACH Purpose: This refers to the purpose for which the terminal performs random access. There are various situations in which a terminal performs random access. Due to insufficient uplink resources for Measurement Report (MR) transmission, or to acquire uplink resources for other purposes, the terminal may perform random access. In this case, the purpose value can be configured as "noPUCCHResourceAvailable". Alternatively, when the base station has already indicated random access to the terminal via PDCCH, the purpose value can be configured as "pdcchOrder". Alternatively, depending on the purpose of the purpose value, it can be configured based on the following: "accessRelated" for initial access, "beamFailureRecovery" for notifying the network of beam failures, "reconfigurationWithSync" and "ulUnSynchronized" for target cell access during handover, "schedulingRequestFailure" for notifying of scheduling request failures, "sCellAdditionTAAdjustment" for SCell addition and timing adjustments, and "requestForOtherSI" for requesting system information.

[0201] - Cell Identifier: This indicates the identifier of the cell in which the terminal has performed random access, and may include the cell identifier. The cell identifier may include the PLMN identifier of the cell in which RACH has been completed, as well as the corresponding cell identifier. A combination of the physical cell ID and the base station ID can be an example of a cell identifier. Alternatively, the cell identifier can be a specific identifier that can uniquely distinguish a cell within the PLMN. Additionally, the cell identifier may refer to NR CGI.

[0202] -absoluteFrequencyPointA: This indicates the absolute frequency location information of the cell where random access was performed, and can be the absolute frequency location of a reference resource block.

[0203] -locationAndBandwidth: This is a value represented as an integer and can be the bandwidth of the frequency domain location and bandwidth portion associated with the random access resources used by the UE.

[0204] -subcarrierSpacing: This refers to the subcarrier spacing information used in the BWP that has already performed random access at the terminal.

[0205] -msg1-FrequencyStart: This is a value represented as an integer and can be the offset of the lowest PRACH transmission timing in the frequency domain relative to PRB 0 of the UL BWP.

[0206] -msg1-SubcarrierSpacing: This refers to the subcarrier spacing of the PRACH resource information.

[0207] -perRACHInfoList: This refers to information representing detailed information about each trial during random access, in chronological order. This can represent detailed information about the reference signal considered at each trial. This field can include detailed information about consecutive random access trials for the same consecutive SSB or CSI-RS. The details include the number of preamble codes sent to the corresponding RS for each SSB or CSI-RS, whether contention occurred in each period when the preamble codes were sent to the corresponding RS, and indicators of the downlink RSRP receive strength of the RS in the corresponding period.

[0208] The terminal can generate a RACH report in operation 1010, or update or modify the VarRACH-Report described below in operation 1020. The terminal can add the EPLMN list to individual entries based on the RACH report generated in the plmnIdentityList of the VarRACH-report. Additionally, the terminal can add the generated RACH report to the RACH report list of the VarRACH-report. Elements added to the plmnIdentityList and elements added to the RACH report list should be related to each other. For example, the two elements should have the same entry order.

[0209] According to another embodiment of this disclosure, when the EPLMN lists used for multiple generated RACH reports are the same, the corresponding RACH report can be associated with an EPLMN regardless of the order of the entries, and the ID of the EPLMN list associated with each RACH report can be given.

[0210] According to another embodiment of this disclosure, when a predetermined time has elapsed, the terminal can discard the RACH report generated according to each random access trial from the VarRACH-Report. In this case, the EPLMN list associated with each discarded RACH report can also be discarded in operation 1025.

[0211] Figure 11 This illustration shows a sequence of terminal operations in a wireless communication system for transmitting all RACH reports stored in variables related to RACH report transmission, according to embodiments of the present disclosure.

[0212] refer to Figure 11In operation 1105, the terminal can receive a UEInformationRequest message from the base station (or, the UEInformationRequest message can be replaced by a pre-defined RRC-specific signaling message). When the message received in operation 1110 includes an indicator requesting a RACH report (RACH-ReportReq) and VarRACH-report includes any content, in operation 1115, the terminal can determine whether the registered PLMN (RPLMN) is included in the plmnIdentityList of VarRACH-Report.

[0213] When the terminal's RPLMN is currently included in the plmnIdentityList of VarRACH-Report, during operation 1120, when the UEInformationResponse message is generated, the terminal can add the RACH-Report list stored in VarRACH-Report to the message. When the successful transmission of the UEInformationResponse message is recognized from the lower layer, the terminal can discard the contents of the corresponding RACH-Report list.

[0214] Figure 12 This illustrates a sequence of terminal operations in a wireless communication system for transmitting a portion of a RACH report stored in variables related to RACH report transmission, according to embodiments of the present disclosure.

[0215] When it has already been executed in the previous operation Figure 10 When performing operation 1020, the following examples can be executed.

[0216] refer to Figure 12 In operation 1205, the terminal can receive a UEInformationRequest message from the base station (or, the UEInformationRequest message can be replaced by a pre-defined RRC-specific signaling message). When the message received in operation 1210 includes an indicator requesting a RACH report (RACH-ReportReq) and the VarRACH report includes any content, in operation 1215, the terminal can determine whether the terminal's RPLMN is currently included in the plmnIdentityList of the VarRACH-Report.

[0217] When the terminal's RPLMN is currently included in the plmnIdentityList of the VarRACH-Report, in operation 1220, when generating the UEInformationResponse message, the terminal may include in the response message the RACH report associated with the entry in the plmnIdentityList of the VarRACH-report (or entries in the RACH-report list in the same order) to which the RPLMN is currently included. In this case, the plmnIdentityList of the corresponding entry may also be included in the UEInformationResponse along with each associated RACH report. When the successful transmission of the UEInformationResponse message is recognized from the lower layer, the terminal may discard the contents of the plmnIdentityList and the corresponding RACH-Report from the VarRACH-Report variable.

[0218] Figure 13a This illustrates a sequence of terminal operations related to RACH reporting in a wireless communication system according to an embodiment of the present disclosure.

[0219] Figure 13b This illustrates a sequence of terminal operations related to RACH reporting in a wireless communication system according to an embodiment of the present disclosure.

[0220] refer to Figure 13a When the terminal enters the RRC connection state in operation 1305, the terminal can receive measurement configuration information from the base station in operation 1310. The configuration information may include indicators that indicate the UL delay ratio or UL delay value.

[0221] The UL delay ratio configuration information may include multiple DRB IDs and UL delay threshold information used to determine the ratio for each DRB. When indicators are included, in operation 1315, the terminal can measure the UL delay in the PDCP entity of the DRB specified by each DRB ID. When the ratio value is derived from all PDCP entities, in operation 1325, the terminal can begin the measurement reporting operation.

[0222] The UL delay value configuration information can also include multiple DRB IDs. When the terminal receives the UL delay value configuration information, it can measure the UL delay in the PDCP entity of the DRB specified by each DRB ID. When the delay value is derived from all PDCP entities, the terminal can begin the measurement reporting operation in operation 1325. Operation 1320 can be performed by operations other than those described above. Figure 8 The operation shown is used instead.

[0223] When a terminal initiates a measurement report operation and there are no uplink resources available for transmission, in operation 1330, the terminal can perform random access to request resources. Upon completion of random access in operation 1335, the terminal can generate a RACH report in operation 1340 and manage the Var-RACH report in operation 1345. Operation 1340 can be used... Figure 9 Operation 910 in Figure 10 Operation 1010 or other embodiments described above can be used instead. Because RACH execution is caused by a shortage of resources for MR transmission, noPUCCHResourceAvailable can be included in the destination field of the RACH report.

[0224] Operation 1345 can be used Figure 9 Operation 920 in Figure 10 Alternatively, operation 1020 or other embodiments described above may be used.

[0225] refer to Figure 13b When the serving base station instructs the terminal to trigger random access via PDCCH after RACH execution is complete, RACH report generation and VarRACH-Report management are completed in operation 1350, and the terminal can perform random access in operation 1355. When random access is completed in operation 1360, the terminal can generate a RACH report. In this case, the destination can be indicated as "pdcchOrder", and the remaining operations can be the same as in operation 1340. Additionally, in operation 1365, the terminal can perform VarRACH-Report management based on the generated RACH report.

[0226] When the terminal receives a UEInformationRequest message from the base station shortly after operation 1370, in operation 1375, the terminal can identify whether the message includes an indicator requesting a RACH report. If the UEInformationRequest message includes the indicator requesting a RACH report, in operation 1380, the terminal can identify whether the RPLMN is currently included in the plmnIdentityList of VarRACH-report. If the RPLMN is not included in the plmnIdentityList of VarRACH-report, the terminal can include the current VarRACH-Report from the RACH-report list in the UEInformationResponse message in operation 1385, and send it to the base station in operation 1390. Operation 1380 can use... Figure 11 Operations 1115 and 1120 in the middle Figure 12Operations 1215 and 1220, or other embodiments described above, may be used instead. In operation 1395, when the terminal has successfully sent a RACH report to the base station, the terminal may discard the contents of the VarRACH-Report included in the transmission.

[0227] 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 therein without departing from the spirit and scope of this disclosure as defined by the appended claims and their equivalents.

Claims

1. A method performed by a terminal in a wireless communication system, the method comprising: performing a random access procedure with a base station; based on the completed random access procedure, identifying whether public land mobile network (PLMN) information associated with the terminal is not included in a PLMN identification list stored in a variable for a random access report; in case that the PLMN information is not included in the PLMN identification list stored in the variable for the random access report, clearing first information for the random access report stored in the variable for the random access report; and adding second information for the random access report associated with the completed random access procedure to the variable for the random access report, wherein the PLMN identification list stored in the variable for the random access report is set to the PLMN information associated with the terminal. The PLMN information associated with the terminal includes information on equivalent PLMNs stored in the terminal.

2. The method of claim 1, wherein, In case that the PLMN information is included in the PLMN identification list stored in the variable for the random access report, the second information for the random access report associated with the completed random access procedure is added to the variable for the random access report without being cleared.

3. The method of claim 1, wherein, 4.The method of claim 1, The information on the random access report includes information on a cell identification and information on a purpose of the random access. wherein 5.The method of claim 1, the method further comprising: receiving, from the base station, a request message for terminal information; and transmitting, to the base station, a response message in response to the request message, wherein the response message is generated based on the information on the random access report included in the variable for the random access report. 6.The method of claim 4, The information on the purpose of the random access includes information for a first random access, information on a beam failure recovery, information for accessing a target cell during handover, and information on uplink synchronization. 7.The method of claim 4, wherein The information on the cell identification is associated with a cell global identification (CGI). 8.The method of claim 4, the method further comprising: wherein in case that a predetermined time elapses, discarding, from the variable for the random access report, the information on the random access report according to each random access trial. 9.A terminal in a wireless communication system, the terminal comprising: a transceiver; and at least one processor configured to: perform a random access procedure with a base station, based on the completed random access procedure, identify whether public land mobile network (PLMN) information associated with the terminal is not included in a PLMN identification list stored in a variable for a random access report, ​ ​ ​ in case that the PLMN information is not included in a PLMN identity list stored in a variable for random access reporting, clearing first information for random access reporting stored in the variable for random access reporting, and adding second information for random access reporting associated with the completed random access procedure to the variable for random access reporting, wherein a PLMN identity list stored in the variable for random access reporting is set to the PLMN information associated with the terminal.

10. The terminal according to claim 9, wherein The PLMN information associated with the terminal includes information on equivalent PLMNs stored in the terminal.

11. The terminal according to claim 9, wherein in case that the PLMN information is included in a PLMN identity list stored in the variable for random access reporting, the second information for random access reporting associated with the completed random access procedure is added to the variable for random access reporting without being cleared. 12.The terminal of claim 9, wherein, The information on the random access report includes information on a cell identity and information on a purpose of the random access. 13.The terminal of claim 9, the at least one processor configured to: receive, via the transceiver, a request message for terminal information from the base station, and transmit, via the transceiver, a response message to the base station in response to the request message, wherein the response message is generated based on the information on the random access report included in the variable for random access reporting. 14.The terminal of claim 12, wherein The information on the purpose of the random access includes information for a first random access, information on a beam failure recovery, information for accessing a target cell during handover, and information on uplink out-of-sync. 15.The terminal of claim 12, wherein The information on the cell identity is associated with a cell global identity (CGI). 16.The terminal of claim 12, the at least one processor configured to: in case that a predetermined time elapses, discard the information on random access report according to each random access trial from the variable for random access reporting.

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