Method and apparatus for reporting terminal capabilities in a wireless communication system

Abstract

The present disclosure is a communication method for a terminal in a wireless communication system, and the communication method includes the following steps: receiving, from a base station, a terminal capability information request triggered by a core network, and sending, to the base station, a non-access stratum (NAS) message including a terminal capability identifier, where the terminal capability identifier is allocated by the core network through NAS signaling.

Description

Technical Field

[0001] The present disclosure relates to a method and apparatus for reporting user equipment (UE) capabilities in a wireless communication system. The present disclosure may include a method for a UE to report the UE's capabilities in a wireless communication system. Background Art

[0002] Due to the commercialization of the fourth generation (4G) communication systems, efforts have been made to develop improved fifth generation (5G) communication systems or pre-5G communication systems in order to meet the increasing demand for wireless data traffic. For this purpose, 5G communication systems or pre-5G communication systems are also referred to as ultra 4G network communication systems or post long term evolution (LTE) systems. The 5G system defined by the 3rd Generation Partnership Project (3GPP) is referred to as a New Radio (NR) system. In order to achieve higher data transmission rates, it is being considered to implement the development of communication systems in the super high frequency band millimeter wave (mmWave) such as 60 GHz. In the 5G communication system, beamforming, massive multiple input multiple output (MIMO), full dimensional MIMO (FD-MIMO), array antennas, analog beamforming, and massive antenna technologies have been discussed to mitigate the propagation path loss of radio waves and increase the propagation distance of radio waves in the super high frequency band, and these technologies are also applied to the NR system. For the improvement of the system network, in the 5G communication system, the development of technologies such as evolved small cells, advanced small cells, cloud radio access network (RAN), ultra-dense network, device-to-device (D2D) communication, wireless backhaul, mobile network, cooperative communication, coordinated multi-point (CoMP), and interference cancellation has been completed. In addition, for the 5G system, other technologies have been developed, such as hybrid frequency shift keying (FSK) with quadrature amplitude modulation (QAM) (FQAM) and sliding window superimposed coding (SWSC) as advanced coding modulation (ACM) schemes, and filter bank multi-carrier (FBMC), non-orthogonal multiple access (NOMA), and sparse code multiple access (SCMA) as advanced access schemes.

[0003] The Internet is a human - centered connectivity network where humans generate and consume information, and it is now evolving into the Internet of Things (IoT), in which distributed entities such as objects exchange and process information. The Internet of Everything (IoE) has also emerged, which is a combination of IoT technology and big data processing technology through connections with cloud servers, etc. To implement IoT, various technical elements are required, such as sensing technology, wired / wireless communication and network infrastructure, service interface technology, and security technology, and recently, technologies related to sensor networks for connecting objects, machine - to - machine (M2M), and machine - type communication (MTC), etc., have been studied. Such an IoT environment can provide intelligent Internet technology (IT) services that create new value for human life by collecting and analyzing the data generated between connected objects. Through the integration and combination of existing information technology (IT) and various industries, IoT can be applied to multiple fields, including smart homes, smart buildings, smart cities, smart cars or connected vehicles, smart grids, healthcare, smart appliances, and advanced medical services, etc.

[0004] Therefore, various attempts have been made to apply the 5G communication system to IoT networks. For example, 5G communication has been implemented through schemes such as beamforming, MIMO, and array antennas for applications such as sensor networks, M2M, MTC, etc. Cloud RAN, as an application of big data processing technology, can also be an example of the integration of 5G technology and IoT technology.

[0005] With the development of the aforementioned technologies and wireless communication systems, various services can be provided. Therefore, a way to effectively provide such services is needed. Summary of the Invention

[0006] Technical Problem

[0007] The disclosed embodiments provide an apparatus and method for effectively providing services in a wireless communication system.

[0008] Solution to the Problem

[0009] The disclosed embodiments provide an apparatus and method for effectively providing services in a wireless communication system.

[0010] Advantageous Effects of the Disclosure

[0011] According to the disclosed embodiments, services can be effectively provided in a wireless communication system. Brief Description of the Drawings

[0012] Figure 1a Shows the structure of a Long - Term Evolution (LTE) system according to an embodiment.

[0013] Figure 1bShows the radio protocol architecture in an LTE system according to an embodiment.

[0014] Figure 1c Shows the structure of a next-generation mobile communication system according to an embodiment.

[0015] Figure 1d Shows the radio protocol architecture of a next-generation mobile communication system according to an embodiment.

[0016] Figure 1e Shows a message structure for supporting user equipment (UE) capabilities in a New Radio (NR) or 5th Generation (5G) communication system according to an embodiment.

[0017] Figure 1f Is a view for describing the state in which a UE in an NR or 5G communication system according to an embodiment registers or deregisters in a 5G core network.

[0018] Figure 1g Is a view for describing the operation of identifying UE capabilities according to an embodiment.

[0019] Figure 1h Is a view for describing the operation when the identification of UE capabilities fails according to an embodiment.

[0020] Figure 1i Is a view for describing the operation of providing and applying a UE capability identifier based on a Public Land Mobile Network (PLMN) according to an embodiment.

[0021] Figure 1j Is a view for describing the operation of updating a UE capability identifier based on a PLMN according to an embodiment.

[0022] Figure 1k Is a view for describing the operation of being assigned and updated a UE capability identifier based on a PLMN according to an embodiment.

[0023] Figure 1l Is a block diagram of the structure of a UE according to an embodiment.

[0024] Figure 1m Is a block diagram of the structure of a base station according to an embodiment.

[0025] Figure 2a Shows the structure of an LTE system according to an embodiment.

[0026] Figure 2b Shows the radio protocol architecture in an LTE system according to an embodiment.

[0027] Figure 2c Shows the structure of a next-generation mobile communication system according to an embodiment.

[0028] Figure 2d shows the radio protocol architecture of a next-generation mobile communication system according to an embodiment.

[0029] Figure 2e is a flowchart according to an embodiment for describing a case where a secondary cell group change and a handover request are performed through one radio resource control (RRC) message.

[0030] Figure 2f is a flowchart according to an embodiment for describing the existing UE operation in a case where a secondary cell group change and a handover request are performed through one radio resource control (RRC) message.

[0031] Figure 2g is a flowchart according to an embodiment for describing a method of sequentially performing random access to a primary cell group and a secondary cell group in a case where a secondary cell group change and a handover request are performed through one radio resource control (RRC) message.

[0032] Figure 2h is a block diagram of the structure of a UE according to an embodiment.

[0033] Figure 2i is a block diagram of the structure of a base station according to an embodiment. Detailed Description

[0034] A communication method of a user equipment (UE) in a wireless communication system according to an embodiment of the present disclosure includes: receiving, from a base station, a UE capability information request triggered by a core network, and sending, to the base station, a non-access stratum (NAS) message including a UE capability identifier, where the UE capability identifier is assigned by the core network through NAS signaling.

[0035] The UE capability information request may include radio access technology (RAT) type information, and the UE capability identifier may be configured based on the RAT type information.

[0036] The UE capability identifier may include a UE capability identifier based on a public land mobile network (PLMN) or a UE capability identifier based on a manufacturer.

[0037] Only a certain number of UE capability identifiers based on the PLMN can be stored in the UE, and when the number of UE capability identifiers based on the PLMN exceeds a certain number, the previously stored UE capability identifiers based on the PLMN may be deleted.

[0038] Sending the NAS message including the UE capability identifier may include sending the NAS message including the UE capability identifier based on the manufacturer when the UE is not assigned a UE capability identifier based on the PLMN.

[0039] The communication method may further include determining whether the UE's capability information has changed, and when the UE's capability information has changed, receiving, based on the determined result, a message including information indicating that a new PLMN-based UE capability identifier needs to be updated.

[0040] The communication method may include storing, in the form of a mapping table, a UE capability identifier corresponding to the UE's capability information and the UE's capability information.

[0041] A communication method of an entity in a core network in a wireless communication system according to an embodiment of the present disclosure includes: sending, via a base station, a message requesting UE capability information to the UE, and receiving, via the base station, a NAS message including a UE capability identifier, where the UE capability identifier is assigned by the core network via NAS signaling.

[0042] The UE capability information request may include RAT type information, and the UE capability identifier may be configured based on the RAT type information.

[0043] The communication method may further include: identifying the UE capability identifier, and determining whether UE capability information corresponding to the UE capability identifier is stored, where the UE capability identifier and the UE capability information are stored in the form of a mapping table.

[0044] The UE capability identifier may include a PLMN-based UE capability identifier or a manufacturer-based UE capability identifier.

[0045] Receiving the NAS message including the UE capability identifier may include receiving, when the UE has not been assigned a PLMN-based UE capability identifier, the NAS message including a manufacturer-based UE capability identifier.

[0046] The communication method may further include receiving, based on the determined result, a message including information indicating that a new PLMN-based UE capability identifier needs to be updated when the UE's capability information has changed.

[0047] According to an embodiment of the present disclosure, a UE for providing UE capability information in a wireless communication system includes a transceiver and at least one processor coupled to the transceiver, the processor configured to receive, from a base station, a UE capability information request triggered by a core network, and send, to the base station, a non-access stratum (NAS) message including a UE capability identifier, where the UE capability identifier is assigned by the core network via NAS signaling.

[0048] According to an embodiment of the present disclosure, an entity in a core network that communicates based on UE capability information in a wireless communication system includes a transceiver and at least one processor coupled to the transceiver. The processor is configured to send, via a base station, a message requesting UE capability information to the UE, and receive, via the base station, a non-access stratum (NAS) message including a UE capability identifier, where the UE capability identifier is assigned by the core network via NAS signaling.

[0049] Hereinafter, the operation principle of the present disclosure will be described in detail with reference to the accompanying drawings. In addition, if a detailed description of known functions or elements associated with the present disclosure unnecessarily obscures the subject matter of the present disclosure, such description will be omitted. Further, the terms to be described below are defined in consideration of the functions in the present disclosure and may vary according to the intention or practice of a user or an operator. Therefore, the terms should be defined based on the overall disclosure. As used in the following description, terms for identifying access nodes, terms for referring to network entities, terms for referring to messages, terms for referring to interfaces between network entities, and terms for referring to various identification information are shown for ease of description. Accordingly, the present disclosure is not limited to the terms used below, and other terms indicating targets having equivalent technical meanings may be used.

[0050] Hereinafter, for ease of description, the present disclosure adopts the terms and names defined in the 3rd Generation Partnership Project Long Term Evolution (3GPP LTE) standard. However, the present disclosure is not limited to such terms and names and may equally apply to systems compliant with other standards.

[0051] In the following, embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. When it is determined that the subject matter of the present disclosure is unclear, the specific description of related functions or configurations may be skipped. Terms used herein are defined in consideration of the functions in the present disclosure, and the terms may be replaced with other terms according to the intention or practice of a user or an operator. Therefore, the terms should be defined based on the overall disclosure. In the following, a base station is an entity that performs resource allocation for a terminal, and may be at least one of a gNode B, an evolved Node B (eNode B), a Node B, a base station (BS), a radio access unit, a base station controller, or a node on a network. A terminal may include a user equipment (UE), a mobile station (MS), a cellular phone, a smart phone, a computer, or a multimedia system capable of performing a communication function. In the present disclosure, a downlink (DL) may represent a radio transmission path for a signal transmitted from a base station to a UE, and an uplink (UL) may represent a radio transmission path for a signal transmitted from a UE to a base station. Although embodiments of the present disclosure are described by using a New Radio (NR) system or a Long Term Evolution (LTE) / LTE-Advanced (LTE-A) system as an example, embodiments of the present disclosure may also be applied to other communication systems having a similar technical background or channel form. For example, a fifth generation mobile communication technology (5G, NR) developed after LTE-A may be included in the communication system. In addition, embodiments of the present disclosure may also be applied to other communication systems with some modifications based on the determination of a person skilled in the art within a range that does not substantially deviate from the scope of the present disclosure.

[0052] According to an embodiment, in order to reduce signaling overhead of UE capability reporting in a process in which a UE receives a request for UE capability from a base station and reports the UE capability to the base station, identifier information specified for UEs having the same UE capability may be used to replace the UE capability reporting. The method according to an embodiment may include a UE identifier access method based on a manufacturer and a UE identifier access method based on a Public Land Mobile Network (PLMN). According to an embodiment, the present disclosure may provide an overall operation of a method of using a PLMN-based UE identifier to transfer UE capability.

[0053] When a base station instructs an NR UE to report UE capability for Multi-Radio Access Technology (RAT) (MR)-Dual Connectivity (DC), a UE capability reporting process performed by the UE according to an embodiment may be clearly defined. Therefore, the UE may accurately transfer its capability, and the base station may accurately understand the UE's capability and provide appropriate configuration information.

[0054] Figure 1a The structure of a Long Term Evolution (LTE) system according to an embodiment is shown.

[0055] Reference Figure 1a, the radio access network in the LET system may include next-generation base stations (evolved Node B (eNB), Node B, or base station) 1a-05, 1a-10, 1a-15, and 1a-20, a Mobility Management Entity (MME) 1a-25, and a Serving Gateway (S-GW) 1a-30. A User Equipment (UE or terminal) 1a-35 may be connected to an external network through eNBs 1a-05 to 1a-20 and S-GW 1a-30.

[0056] In Figure 1a , base stations 1a-05 to 1a-20 may correspond to existing Node Bs in a Universal Mobile Telecommunications System (UMTS). An eNB may be connected to UE 1a-35 through a radio channel and play a more complex role than an existing Node B. In the LTE system, each user traffic and real-time services such as Voice over Internet Protocol (VoIP) are provided through a shared channel, which requires means for collecting UE's status information (such as buffer status, available transmit power status, channel status, etc.) and performing scheduling based on the status information. Examples of such devices may be eNBs 1a-05 to 1a-20. Generally, one eNB may control multiple cells. For example, to implement a transmission rate of 100 Mbps, the LTE system may use, for example, Orthogonal Frequency Division Multiplexing (OFDM) as a radio connection scheme in a 20 MHz bandwidth. Similarly, Adaptive Modulation and Coding (AMC) may be used, where the modulation scheme and channel coding rate are determined based on the UE's channel status. S-GW 1a-30 may be a device for providing data bearers and generating or removing data bearers under the control of MME 1a-25. MME 1a-25 may be responsible for various control functions and UE's mobility management functions and may be connected to multiple base stations.

[0057] Figure 1b Shows the radio protocol architecture in the LTE system according to an embodiment.

[0058] Refer to Figure 1b , the radio protocol of the LTE system may respectively include Packet Data Convergence Protocol (PDCP) 1b-05 and 1b-40, Radio Link Control (RLC) 1b-10 and 1b-35, and Medium Access Control (MAC) 1b-15 and 1b-30 at the UE and eNB. PDCP 1b-05 and 1b-40 may be responsible for IP header compression / decompression, etc. The main functions of PDCP may be summarized as follows:

[0059] - Header compression and decompression (only ROHC)

[0060] - Transmission of user data

[0061] - Deliver upper layer PDUs sequentially during the PDCP re - establishment procedure for RLC AM

[0062] - For split bearers in DC (RLC acknowledged mode (AM) only): PDCP PDU routing for transmission and PDCP PDU re - ordering for reception

[0063] - Re - detect lower layer SDUs during the PDCP re - establishment procedure for RLC AM

[0064] - Resend PDCP SDUs upon handover for RLC AM and resend PDCP PDUs during the PDCP data recovery procedure for split bearers in DC

[0065] - Encryption and decryption

[0066] - Timer - based SDU discard in the uplink

[0067] RLC 1b - 10 and 1b - 35 can reconstruct PDCP protocol data units (PDUs) to an appropriate size and perform automatic repeat request (ARQ) operations. The main functions of RLC can be summarized as follows:

[0068] Delivery of upper layer PDUs

[0069] - Error correction via ARQ (for AM data transfer only)

[0070] - Concatenation, segmentation, and reassembly of RLC SDUs (for UM and AM data transfer only)

[0071] - Re - segmentation of RLC data PDUs (for AM data transfer only)

[0072] - Re - ordering of RLC data PDUs (for UM and AM data transfer only)

[0073] - Duplicate detection (for UM and AM data transfer only)

[0074] - Protocol error detection (for AM data transfer only)

[0075] - RLC SDU discard (for UM and AM data transfer only)

[0076] RLC re - establishment

[0077] MAC layer 1b - 15 and 1b - 30 can be connected to multiple RLC layer entities configured in a UE, multiplex RLC PDUs into MAC PDUs, and demultiplex MAC PDUs into RLC PDUs. The main functions of MAC can be summarized as follows:

[0078] - Mapping between logical channels and transport channels

[0079] - Multiplexing MAC SDUs belonging to one or different logical channels into transport blocks (TBs) delivered to the physical layer on a transport channel / Demultiplexing MAC SDUs from transport blocks delivered from the physical layer on a transport channel

[0080] - Scheduling information reporting

[0081] - Error correction by Hybrid Automatic Repeat reQuest (HARQ)

[0082] - Priority handling between logical channels of a UE

[0083] - Priority handling between UEs by means of dynamic scheduling

[0084] - MBMS service identification

[0085] - Transmission format selection

[0086] - Padding

[0087] The physical (PHY) layer 1b - 20 and 1b - 25 can perform channel coding and modulation of the upper layer data, and convert the data into OFDM symbols to transmit the OFDM symbols through a radio channel, or demodulate the OFDM symbols received through the radio channel and perform channel decoding of the OFDM symbols to deliver the OFDM symbols to the upper layer. For further error correction in the physical layer, HARQ is used, where the receiving end sends 1 bit as information on whether a packet sent from the transmitting end has been received. This information can be referred to as HARQ ACK / NACK information. The DL HARQ ACK / NACK information for UL transmission can be transmitted through the physical Hybrid ARQ indicator channel (PHICH) physical channel, and the UL HARQ ACK / NACK information for DL transmission can be transmitted through the physical uplink control channel (PUCCH) or the physical uplink shared channel (PUSCH) physical channel.

[0088] Meanwhile, the aforementioned PHY layer can include one frequency / carrier or multiple frequencies / carriers, and the technique for simultaneously setting multiple frequencies for using them can be called Carrier Aggregation (CA). CA can additionally use a primary carrier and one or multiple secondary carriers instead of using one carrier for communication between a terminal (or UE) and a base station (Evolved UMTS Terrestrial Radio Access Network (E - UTRAN) NodeB or eNB). By using CA, the transmission volume can be innovatively increased to approximately the number of secondary carriers. Meanwhile, in LTE, the cell using the primary carrier in the base station can be called the Primary Cell (PCell), and the cell using the secondary carrier can be called the Secondary Cell (SCell).

[0089] Although not shown, the Radio Resource Control (RRC) layer may exist on the Packet Data Convergence Protocol (PDCP) layer of the UE and the eNB, respectively, and the RRC layer may exchange configuration control messages related to access or measurement of radio resources control.

[0090] Figure 1c The structure of a next-generation mobile communication system according to an embodiment, such as an NR or 5G communication system, is shown.

[0091] Reference Figure 1c , as shown in the figure, the radio access network of the next-generation mobile communication may include an NR NB1c-10 and an NR core network (CN) or a next-generation (NG) CN 1c-05. A New Radio User Equipment (NR UE or UE) 1c-15 may access an external network through the NR NB 1c-10 and the NR CN 1c-05.

[0092] In Figure 1c , the NR NB 1c-10 may correspond to the eNB in the existing LTE system. The NR NB 1c-10 is connected to the NR UE 1c-15 through a radio channel and may provide services more advanced than those of the existing Node B. In the next-generation mobile communication system, all user traffic is served through a shared channel, which requires a device to collect status information, such as the buffer status of the UE, the available transmission power status, and the channel status, and perform scheduling, where the NR NB 1c-10 may be responsible for these functions. One NR NB1c-10 may generally control multiple cells. In the next-generation mobile communication system, compared with the existing LTE, a bandwidth larger than the existing maximum bandwidth may be applied to achieve ultra-high-speed data transmission. In addition, in addition to OFDM, beamforming technology may be further used. Similarly, adaptive modulation and coding (AMC) may be used, where the modulation scheme and the channel coding rate are determined based on the channel status of the UE.

[0093] The NR CN 1c-05 may perform functions such as mobility support, bearer setup, Quality of Service (QoS) setup, etc. The NR CN 1c-05 may be a device that not only performs mobility management functions for the UE but also performs various control functions, and may be connected to multiple base stations. The next-generation mobile communication system may also cooperate with the existing LTE system, where the NR CN 1c-05 may be connected to the MME 1c-25 through a network interface. The MME 1c-25 may be connected to the eNB 1c-30, which is an existing base station.

[0094] Figure 1d The radio protocol architecture of a next-generation mobile communication system according to an embodiment is shown.

[0095] Reference Figure 1d For example, the radio protocol of the next-generation mobile communication system may include NR Service Data Adaptation Protocol (SDAP) 1d-01 and 1d-45, NR PDCP 1d-05 and 1d-40, NR RLC 1d-10 and 1d-35, and NR MAC 1d-15 and 1d-30 at the UE and NR gNB, respectively.

[0096] The main functions of NR SDAP 1d-01 and 1d-45 may include some of the following functions:

[0097] - Transmission of user plane data

[0098] - Mapping between QoS flows and DRBs for both DL and UL

[0099] - Marking QoS flow IDs in both DL and UL packets

[0100] - Reflective QoS flow to DRB mapping for UL SDAP PDUs

[0101] For the SDAP layer entity, it can be set via RRC messages whether the UE uses the header of the SDAP layer entity or the functions of the SDAP layer entity for each PDCP layer entity, each bearer, or each logical channel. When the SDAP header is set, the Network Attachment Storage (NAS) QoS Reflection Configuration 1-bit indicator (NAS Reflection QoS) and the AS QoS Reflection Configuration 1-bit indicator (AS Reflection QoS) can be used to indicate that the UE can update or reconfigure the QoS flows of UL and DL and the mapping information regarding data bearers. The SDAP header may include QoS flow ID information indicating QoS. The QoS information can be used as data processing priority information, scheduling information, etc. to support smooth services.

[0102] The main functions of NR PDCP 1d-05 and 1d-40 may include some of the following functions:

[0103] - Header compression and decompression (ROHC only)

[0104] - Transmission of user data

[0105] - In-sequence delivery of upper layer PDUs

[0106] - Out-of-sequence delivery of upper layer PDUs

[0107] - PDCP PDU reordering for reception

[0108] - Duplicate detection of lower layer SDUs

[0109] - Retransmission of PDCP SDUs

[0110] - Encryption and decryption

[0111] - Timer-based SDU discarding in the uplink

[0112] In the foregoing description, the reordering function of the NR PDCP entity may involve the function of reordering PDCP PDUs received from the lower layer in sequence based on the PDCP sequence number (SN). The reordering function of the NR PDCP entity may include at least one of the following: delivering data to the upper layer in the reordered sequence; delivering data immediately regardless of the order; recording PDCP PDUs lost due to reordering; reporting the status of the lost PDCP PDUs to the transmission side or requesting retransmission of the lost PDCP PDUs.

[0113] The main functions of NR RLC 1d-10 and 1d-35 may include some of the following functions:

[0114] - Transmission of upper layer PDUs

[0115] - In-sequence delivery of upper layer PDUs

[0116] - Out-of-sequence delivery of upper layer PDUs

[0117] - Error correction by ARQ

[0118] - Concatenation, segmentation, and reassembly of RLC SDUs

[0119] - Resegmentation of RLC data PDUs

[0120] - Reordering of RLC data PDUs

[0121] - Duplicate detection

[0122] - Protocol error detection

[0123] - RLC SDU discarding

[0124] - RLC re-establishment

[0125] In the foregoing description, the in-sequence delivery function of the NR RLC entity may involve the function of delivering RLC SDUs received from the lower layer to the upper layer in sequence. When an RLC SDU is received in several parts, the in-sequence delivery of the NR RLC entity may include reassembling and delivering the RLC SDU.

[0126] In-sequence delivery of the NR RLC entity may include at least one of the following functions: the function of reassembling and delivering multiple RLC SDUs when an original RLC SDU is divided into multiple RLC SDUs to be received; the function of rearranging received RLC PDUs based on the RLC SN or PDCP SN; the function of recording lost RLC PDUs by reordering; the function of reporting the status of lost RLC PDUs to the transmitter; the function of requesting retransmission of lost RLC PDUs; the function of delivering only the RLC SDUs before the lost RLC SDU to the upper layer in sequence in the case of RLC SDU loss; the function of delivering all RLC SDUs received before the timer expiration to the upper layer in sequence when the timer expires despite the presence of lost RLC SDUs; or the function of delivering all currently received RLC SDUs to the upper layer in sequence when the timer expires despite the presence of lost RLC SDUs.

[0127] The NR RLC entity may process them in the order of receiving RLC PDUs (in the order of arrival, regardless of the order of sequence numbers or sequence identifiers), and may deliver them to the PDCP entity regardless of the order (out-of-sequence delivery). When the NR RLC entity receives segmentation, the NR RLC entity may receive the segments stored in the buffer or to be received later, reconfigure them into a complete RLC PDU, then process the RLC PDU and deliver it to the PDCP entity. The NR RLC layer may not include a concatenation function, and the concatenation function may be performed in the NR MAC layer or may be replaced by the multiplexing function of the NR MAC layer.

[0128] In the foregoing description, out-of-sequence delivery of the NR RLC entity may involve the function of immediately delivering the RLC SDUs received from the lower layer to the upper layer regardless of the order. The out-of-sequence delivery function may include the function of reassembling and delivering multiple RLC SDUs when an original RLC SDU is divided into multiple RLC SDUs to be received, and the function of recording lost RLC PDUs by storing and reordering the RLC SN or PDCP SN of the received RLC PDUs.

[0129] NR MAC 1d-15 and 1d-30 may be connected to multiple NR RLC layer entities configured in a UE, and the main functions of the NR MAC may include some of the following functions:

[0130] - Mapping between logical channels and transmission channels

[0131] - Multiplexing / demultiplexing of MAC SDUs

[0132] - Scheduling information reporting

[0133] -Error correction by HARQ

[0134] -Priority handling between logical channels of a UE

[0135] -Priority handling between UEs by means of dynamic scheduling

[0136] -MBMS service identification

[0137] -Transmission format selection

[0138] -Padding

[0139] The NR PHY layers 1d-20 and 1d-25 can perform channel coding and modulation of the upper layer data, convert the data into OFDM symbols to transmit the OFDM symbols via a radio channel, or demodulate the OFDM symbols received via the radio channel and perform channel decoding of the OFDM symbols to deliver the OFDM symbols to the upper layer.

[0140] Figure 1e Shows a message structure for reporting UE capabilities in an NR or 5G communication system according to an embodiment.

[0141] When the UE 1e-01 is connected to the serving gNB 1e-02, the UE 1e-01 can have a procedure for reporting the capabilities supported by the UE 1e-01 to the serving gNB 1e-02.

[0142] In operation 1e-05, the serving gNB 1e-02 can transmit a UE capability query message requesting a capability report to the connected UE 1e-01. The aforementioned UE capability query message can include a UE capability request of the serving gNB 1e-02 based on the RAT type. The RAT type-based request can include a request for frequency band information according to the priority.

[0143] The above UE capability query message can request multiple RAT types in one RRC message container. At the same time, the serving gNB 1e-02 can send the UE capability query message including the RAT type-based request to the UE 1e-01 multiple times. That is, the UE capability query in operation 1e-05 can be repeated multiple times, and the UE 1e-01 can configure the UE capability information message by matching the responses to the repeated UE capability queries and report the configured UE capability information message. In the next-generation mobile communication system, it is possible to request UE capabilities for MR-DC and NR, LTE, and E-UTRAN NR-DC (EN-DC). In an embodiment, the above UE capability query message can generally be sent in the initial stage after the UE performs the connection, but when required by the base station, the UE capability can be requested under specific conditions.

[0144] UE 1e-01 that has received a UE capability report request from serving gNB 1e-02 can configure UE capabilities based on the RAT type and frequency band information requested from serving gNB 1e-02. Hereinafter, a method for configuring UE capabilities in an NR system performed by UE 1e-01 according to an embodiment will be described.

[0145] The UE can be requested by a UE capability request from a base station to provide some or all of LTE, EN-DC, and NR as RAT types. At the same time, a list of LTE and NR frequency bands can be provided to the UE. In an embodiment, the UE can configure a band combination (BC) for EN-DC and NR stand-alone (SA). That is, based on the frequency bands requested from the base station through FreqBandList, the UE can configure a list of candidate BCs for EN-DC and NR SA. The foregoing operation can be defined as an operation of compiling candidate frequency band combinations. The frequency band priority can be based on the order described in FreqBandList. In an embodiment, regardless of the RAT type, the foregoing operation can be performed once, or can be repeated for each RAT type.

[0146] In the following embodiments, corresponding processes can be performed for each RAT type based on the priority of NR, MR-DC, and then LTE.

[0147] When the "eutra-nr-only" flag or "eutra" flag is set in the RAT type of the UE capability request message, the NR SA BC can be completely removed from the configured candidate BC list. In an embodiment, when the LTE eNB requests "eutra" capabilities, the foregoing operation can be performed.

[0148] Thereafter, the UE can remove the fallback BC from the configured candidate BC list. Here, the fallback BC can correspond to a case where the frequency bands corresponding to at least one SCell are removed from a certain superset BC. The superset BC may be able to cover the fallback BC, so the fallback BC can be omitted. This operation can also be applied to EN-DC, i.e., the LTE frequency band. The BCs remaining after this operation can be the final "candidate BC list".

[0149] The UE can select the BC to be reported by selecting a BC suitable for the requested RAT type from the final "candidate BC list". In this step, the UE can configure the supportedBandCombinationList in a determined order. That is, the UE can configure the BC to be reported and UE capabilities according to a preset RAT type order (nr->eutra-nr->eutra).

[0150] The UE can configure a featureSetCombination for the configured supportedBandCombinationList, and can configure a list of "candidate feature set combinations" in the candidate BC list, and remove the fallback BC list (with the same or lower level of capabilities) from the candidate BC list. In an embodiment, the "candidate feature set combinations" can include all feature set combinations of NR and EUTRA-NR BCs, and can be obtained from the feature set combinations of the UE-NR capabilities and UE-MRDC capabilities containers.

[0151] When the requested RAT type is EUTRA-NR and it has an impact on the supportedBandCombination of EN-DC or MR-DC, the featureSetCombination can be configured according to the corresponding RAT type and can be included in both the UE-MRDC capabilities and UE-NR-capabilities containers. However, the feature sets of NR can only include the UE NR capabilities.

[0152] After the UE capabilities are configured, in operation 1e-10, the UE 1e-01 can transmit a UE capability information message including the UE capabilities to the serving gNB 1e-02. The serving gNB 1e-02 can perform appropriate scheduling and transmit / receive management on the UE 1e-01 based on the UE capabilities received from the UE 1e-01.

[0153] In an embodiment, to reduce the complexity of the existing procedures for requesting and reporting UE capabilities applied to the NR system, a method of replacing UE capability reporting by representing the UE capabilities with an identifier (ID) can be considered. Generally, the UE can configure the same UE capabilities according to the manufacturing number or the model specified by the manufacturer of the UE. In addition, when the base station and the core network have the capabilities of the UE, they can store and use it. When the same UE capabilities are reported in the same UE model, the base station and the core network can always receive the same UE capability reports of the UE model, so as to perform optimization for the corresponding operations. That is, when there is an identifier representing the capabilities of the corresponding UE model and the UE can report this identifier, the base station and the core network can determine this identifier and retrieve the UE capabilities. In an embodiment, there are two options for using the identifier representing the UE capabilities.

[0154] - Manufacturer-based UE capability ID: Each manufacturer and each UE model (or UEs with the same UE capabilities in the manufacturer's UEs) may have an identifier, which may be an identifier uniquely representing the radio link UE capabilities of the UE.

[0155] - PLMN-based UE Capability ID: When the manufacturer-based UE capability ID is not provided or the base station and the core network may not recognize the manufacturer-based UE capability ID, an identifier is needed to replace the manufacturer-based UE capability ID so that the base station and the core network can provide a specific identifier to the UE according to the UE capabilities. The identifier may need to be applicable to the serving PLMN and can be specifically assigned to the PLMN.

[0156] In the present disclosure, according to an embodiment, in the UE capability reporting operation using the foregoing two identifiers, an operation of providing the PLMN-based UE capability ID and identifying the UE capabilities by analyzing the PLMN-based UE capability ID can be proposed.

[0157] Figure 1f is a view for describing the state in which a UE in an NR or 5G communication system according to an embodiment registers or deregisters in a 5G core network.

[0158] In operation 1f-05, until the UE is initially registered in the core network in the NR system, the UE can be in the Registration Management (RM)-NULL state in the core network (a base station or an entity of the core network).

[0159] Thereafter, in operation 1f-20, when the UE is enabled in the N1 mode (the mode of connecting to the 5G core network), the UE can exist in the RM-DERESTERED state of the 5G core network as in operation 1f-10. That is, this may mean that the UE may be connected to the 5G core network but has not completed the connection and registration.

[0160] In operation 1f-30, the UE can attempt an initial connection and registration with the 5G core network. After completing the foregoing operation, the UE can switch to the RM-REGISTERED state of operation 1f-15.

[0161] Thereafter, in operation 1f-40, even when the UE performs a process such as a serving cell change, the UE can maintain the RM-REGISTERED state because this operation is not an initial registration operation.

[0162] In operation 1f-35, when the UE is deregistered, the UE can switch back to the RM-DEREGISTERED state.

[0163] In operation 1f-25, when the N1 mode is disabled in this state, the UE can switch back to the RM-NULL state.

[0164] Figure 1g is a view for describing the operation of identifying UE capabilities according to an embodiment. More specifically, Figure 1gThis is a view according to an embodiment for describing the operation of identifying UE capabilities by using a manufacturer-based UE capability ID.

[0165] In operation 1g-05, a UE 1g-01 in the RRC IDLE state can perform an RRC connection procedure with a certain NR gNB 1g-02.

[0166] In operation 1g-10, after the UE 1g-01 performs the RRC connection procedure, the UE 1g-01 can deliver a NAS message (e.g., ATTACH REQUEST) including a manufacturer-based UE capability ID to the core network (CN) 1g-03 to which the corresponding base station is connected.

[0167] In operation 1g-15, the CN 1g-03 that has received the NAS message can identify the manufacturer-based UE capability ID to determine whether the UE capability corresponding to the identifier is stored and identify the UE capability mapped to the identifier. For the foregoing operation, in the CN 1g-03, the manufacturer-based UE capability ID and the UE capability can exist in the form of a mapping table.

[0168] In operation 1g-20, the UE 1g-01 and the CN 1g-03 can perform a process for setting NAS security (authentication).

[0169] In operation 1g-25, the CN 1g-03 can transmit the UE capability known as the result of identifying the manufacturer-based UE capability ID in operation 1g-15 to the gNB 1g-02. The foregoing message can be included in the INITIAL CONTEXT SETUP REQUEST (NAS message). In the foregoing operation, the CN 1g-03 can transmit the manufacturer-based UE capability ID received from the UE 1g-01 together.

[0170] In operation 1g-30, the gNB 1g-02 can store the UE capability received from the CN 1g-03. The gNB 1g-02 can also reflect the UE capability described in the RRC setup with the UE 1g-01. The gNB 1g-02 can know the UE capability through the foregoing process, and thus can not trigger an operation to request the UE capability from the UE.

[0171] Figure 1h This is a view according to an embodiment for describing the operation when UE capability identification fails. More specifically, Figure 1h This is a view according to an embodiment for describing the operation when UE capabilities cannot be identified by using a manufacturer-based UE capability ID.

[0172] In operation 1h-05, the UE 1h-01 in the RRC IDLE state can perform an RRC connection procedure with a certain NR gNB 1h-02.

[0173] In operation 1h-10, after the UE 1h-01 performs the RRC connection procedure, the UE 1g-01 can deliver a NAS message (e.g., ATTACH REQUEST) including a manufacturer-based UE capability ID to the CN 1h-03 to which the corresponding base station is connected.

[0174] In operation 1h-15, the CN 1h-03 that has received the NAS message can identify the manufacturer-based UE capability ID to determine whether the UE capability corresponding to the identifier is stored. In this case, the CN 1h-03 may not be unable to recover the UE capability mapped to the identifier. For the foregoing operation, in the CN, the manufacturer-based UE capability ID and the UE capability can exist in the form of a mapping table. However, in this process, the manufacturer-based UE capability ID provided by the UE may not be stored in the CN 1h-03, or the CN 1h-03 may not understand the manufacturer-based UE capability ID.

[0175] In operation 1h-20, the UE 1h-01 and the CN 1h-03 can perform a process for setting NAS security (authentication).

[0176] In operation 1h-25, the CN 1h-03 can notify the gNB 1h-02 that the CN 1h-03 does not have the UE capability of the UE 1h-01, and deliver an INITIAL CONTEXT SETUP REQUEST message (NAS message) requesting the UE capability to the gNB 1h-02. In the foregoing operation, the CN 1h-03 can transmit the manufacturer-based UE capability ID received from the UE 1h-01 together. In the foregoing operation, the gNB 1h-02 can identify the manufacturer-based UE capability ID received from the CN 1h-03, and when the gNB 1h-02 has the UE capability information corresponding to the identifier and thus can recover the UE capability, the gNB 1h-02 can notify this to the CN 1h-03. Thereafter, the UE capability request process can be omitted.

[0177] In operation 1h-30, the gNB 1h-02 can identify the UE capability request received from the CN 1h-03 and trigger the UE capability request.

[0178] That is, in operation 1h-35, gNB 1h-02 may transmit a UE capability request message (UECapabilityEnquiry) to UE 1h-01, which includes the RAT type and filtering information for requesting UE capabilities.

[0179] In operation 1h-40, UE 1h-01 may, in response to the UE capability request message received in operation 1h-35, configure UE capabilities by reflecting the RAT type and filtering information, and transmit a UE capability information message (UECapabilityInformation) to gNB 1h-02. In the foregoing operation, UE 1h-01 may include a manufacturer-based UE capability ID in the UECapabilityInformation message.

[0180] In operation 1h-45, gNB 1h-02 may store the UE capability information received from UE 1h-01. When the manufacturer-based UE capability ID is received together from UE 1h-01, gNB 1h-02 may store the corresponding information together.

[0181] In operation 1h-50, gNB 1h-02 may store the UECapabilityInformation message received from UE 1h-01 and transmit it to CN 1h-03. UE capabilities, including filtering information, may be carried by different containers for different RAT types.

[0182] In operation 1h-55, CN 1h-03 may store the received UE capabilities and update the UE capability mapping table including the manufacturer-based UE capability ID and UE capabilities. Thereafter, for UEs providing the manufacturer-based UE capability ID, the stored UE capabilities may be applied.

[0183] Figure 1i is a view for describing operations of providing and applying a PLMN-based UE capability identifier according to an embodiment. More specifically, Figure 1i is a view for describing operations of being provided with a PLMN-based UE capability ID and applying it according to an embodiment.

[0184] In operation 1i-05, UE 1i-01 in the RRC IDLE state may perform an RRC connection procedure with a certain NR gNB 1i-02.

[0185] In operation 1i-10, after the UE 1i-01 performs the RRC connection procedure, the UE 1g-01 may deliver a NAS message (e.g., ATTACH REQUEST) including a manufacturer-based UE capability ID to the CN 1i-03 to which the corresponding base station is connected.

[0186] In operation 1i-15, the CN 1i-03 that has received the NAS message may identify the manufacturer-based UE capability ID to determine whether the UE capability corresponding to the identifier is stored. In this case, the CN 1i-03 may not be unable to retrieve the UE capability mapped to the identifier. For the foregoing operation, in the CN, the manufacturer-based UE capability ID and the UE capability may exist in the form of a mapping table. However, during this process, the manufacturer-based UE capability ID provided by the UE may not be stored in the CN1i-03, or the CN 1i-03 may not understand the manufacturer-based UE capability ID.

[0187] In operation 1i-20, the UE 1i-01 and the CN 1i-03 may perform a process for setting NAS security (authentication).

[0188] In operation 1i-25, the CN 1i-03 may notify the gNB 1i-02 that the CN 1i-03 does not have the UE capability of the UE1i-01 and deliver an INITIAL CONTEXT SETUP REQUEST message (NAS message) requesting the UE capability to the gNB 1h-02. In the foregoing operation, the CN 1i-03 may transmit the manufacturer-based UE capability ID received from the UE 1i-01 together. In the foregoing operation, the gNB 1i-02 may identify the manufacturer-based UE capability ID received from the CN 1i-03, and when the gNB 1i-02 has the UE capability information corresponding to the identifier and thus can retrieve the UE capability, the gNB 1i-02 may notify this to the CN1h-03 (a specific entity of the CN) and omit the subsequent UE capability request process.

[0189] In operation 1i-30, the gNB 1i-012 may identify the UE capability request received from the CN 1i-03 and trigger the UE capability request.

[0190] That is, in operation 1i-35, the gNB 1i-02 may transmit a UE capability request message (UECapabilityEnquiry) to the UE 1i-01, which includes the RAT type and filtering information for requesting the UE capability. The RRC message may also include an indicator indicating whether the UE is capable of providing the UE capability ID.

[0191] In operation 1i-40, when the NG gNB 1i-02 has received an indicator indicating whether the UE 1i-10 can provide a UE capability ID (or an indicator indicating that the manufacturer-based UE capability ID is invalid) and has mapped the PLMN-based UE capability ID to a UE capability request including a RAT type and filtering information, the UE 1i-01 may deliver a UE capability information message (UECapabilityInformation) including the corresponding identifier to the gNB. However, when the UE 1i-01 does not have a PLMN-based UE capability ID mapped to the request of the gNB 1i-02, in operation 1i-40, the UE 1i-01 may configure the UE capability by reflecting the RAT type and filtering information as in the existing UE capability reporting procedure, and transmit the UE capability information message (UECapabilityInformation) to the gNB.

[0192] Subsequent operations may be procedures corresponding to the case where the UE reports UE capabilities, because the UE does not have a mapped PLMN-based UE capability ID in operation 1i-40.

[0193] In operation 1i-45, the UE 1i-01 may know that the gNB 1i-02 does not have the UE capabilities corresponding to the manufacturer-based UE capability ID provided by the UE 1i-01 in the foregoing operation, and may know that the UE 1i-01 can receive a PLMN-based UE capability ID mapped to the UE capabilities transmitted to the gNB 1i-02, because the UE 1i-01 has sent its UE capabilities to the gNB 1i-02. Therefore, in the corresponding operation, the UE 1i-01 may store the UE capability information transmitted in operation 1i-40 in an internal buffer (memory) of the UE 1i-01, and store the RAT type and filtering information related to the UE capability requested by the gNB 1i-02. In addition, the UE may store the registered PLMN information of the serving cell connected in the system information SIB1 received from the corresponding serving cell. In summary, in operation 1i-45, the UE 1i-01 may store the PLMN information, RAT type and filtering information, and the reported UE capabilities as a group.

[0194] In operation 1i-50, the gNB 1i-02 may store the UECapabilityInformation message received from the UE 1i-01 and transmit it to the CN 1i-03. The UE capabilities, including filtering information, may be carried by different containers for different RAT types.

[0195] In operation 1i-55, CN 1i-03 can identify the UE capabilities received in the foregoing operations. When there is a PLMN-based UE capability ID mapped to the UE capabilities for filtering information and the requested RAT type reported by UE 1i-01 in the stored table, CN 1i-03 can assign the corresponding identifier as the PLMN-based UE capability ID. However, when the reported UE capability is a new one that the CN does not have, CN 1i-03 can assign a new PLMN-based UE capability ID.

[0196] In operation 1i-60, CN 1i-03 can transmit the PLMN-based UE capability ID assigned corresponding to the UE capabilities reported by UE 1i-02 to UE 1i-01 via a NAS message (e.g., ATTACH RESPONSE). The foregoing message can include index information for indicating the UE capabilities indicated by the identifier or the RAT type and filtering information mapped to the UE capabilities.

[0197] The reason for the corresponding operations is that operations 1i-35 and 1i-40 can be continuously executed instead of being executed once. For example, according to an embodiment, gNB 1i-02 can transmit an NR UE capability request including an RAT type and filtering information to UE 1i-01 in operation 1i-35, and receive the corresponding UE capabilities from UE1i-01 in operation 1i-40, and then repeat operation 1i-35 again to request EN-DC UE capabilities and receive the UE capability report corresponding to operation 1i-40. In this case, gNB1i-20 may have to assign PLMN-based UE capability IDs for the two continuously received UE capabilities respectively, so that index information for distinguishing UE capabilities can be included (e.g., the first UE capability report can be set to 1, and the second UE capability report can be set to 2), or the filtering information can be transmitted together.

[0198] In operation 1i-55, the method of assigning the PLMN-based UE capability ID performed by CN 1i-03 can apply different operations according to the network implementation. For example, in an embodiment, a UE capability report of a specific UE can be received, and when the number of UE reports providing the same UE capabilities as the corresponding UE capabilities is greater than a predetermined threshold N, the corresponding UE capabilities can be specified, and a PLMN-based UE capability ID can be assigned. That is, an algorithm may be required, in which not only a few UE capability reports are used to assign a specific PLMN-based UE capability ID.

[0199] In operation 1i-65, the UE 1i-01 may map the PLMN-based UE capability ID received from the CN 1i-03 in operation 1i-60 to the UE capability storage group reported and stored by the UE 1i-01 in operation 1i-45, and store them newly. That is, the UE 1i-01 may store the PLMN-based UE capability ID, the registered PLMN information, the RAT type and filtering information, and the reported UE capability in one group, and then use the PLMN-based UE capability ID assigned to represent the UE capability. In addition, in the foregoing operation, the number of PLMN-based UE capability IDs that the UE 1i-01 may store in the foregoing operation may be limited. While storing a set number of PLMN-based UE capability IDs, when the UE 1i-01 needs to store the UE capability for a new PLMN-based UE capability ID, the previously stored PLMN-based UE capability ID and the corresponding UE capability group may be deleted, and an update with new values may be performed. In the foregoing operation, the information of the same PLMN may be left, and the information of different PLMNs may be deleted.

[0200] In operation 1i-70, the CN 1i-03 may send the PLMN-based UE capability ID sent to the UE to the gNB 1i-02 through the N1 message.

[0201] In operation 1i-75, the gNB 1i-02 may store the PLMN-based UE capability ID, the registered PLMN information, the RAT type and filtering information, and the reported UE capability as one group based on the received PLMN-based UE capability ID, the UE capability received in operation 1i-40, and the RAT type and filtering information sent to the UE 1i-01 in operation 1i-35. Thereafter, when the UE 1i-01 uses the PLMN-based UE capability ID assigned to represent the UE capability, the gNB 1i-02 that has received the PLMN-based UE capability ID may not trigger a UE capability request.

[0202] Figure 1j is a view for describing the operation of updating the PLMN-based UE capability identifier according to an embodiment. More specifically, Figure 1j is a view for describing the overall operation of updating the PLMN-based UE capability ID due to UE change when applying the PLMN-based UE capability ID according to an embodiment.

[0203] will be described with reference to Figure 1j The described embodiment may be based on the embodiment described with reference to Figure 1i When the UE completes Figure 1iAfter the UE is assigned a PLMN-based UE capability ID during the process, it can change the UE capabilities corresponding to the PLMN-based UE capability ID in a specific context, so it may be necessary to update the PLMN-based UE capability ID. Reference will be made to Figure 1j The described embodiments are intended to describe and define the overall operations of the UE, gNB, and CN in such a case. As an example of the foregoing case, there can be a Universal Subscriber Identity Module (USIM) replacement of the UE, a change of the UE, a temporary UE capability change (e.g., UE heat dissipation, interference with other wireless functions (e.g., wireless network, Bluetooth, etc.)), and others. Thus, the UE capabilities may be changed when compared with the UE capabilities that the UE has reported, and this may mean that the assigned PLMN-based UE capability ID is no longer valid. In this case, the UE can perform the following process in order to be assigned a new PLMN-based UE capability ID corresponding to the changed UE capabilities.

[0204] In operation 1j-05, the UE 1j-01 in the RRC connected state can trigger a process for updating the PLMN-based UE capability ID in order to be assigned a new PLMN-based UE capability ID corresponding to the UE capability change as described above.

[0205] In operation 1j-10, the UE 1j-01 can perform an RRC release process with the connected NR gNB 1j-02. The foregoing operation can be performed by the UE including a specific cause value in the message for requesting RRCRelease. Alternatively, in the foregoing operation, the UE 1j-01 can send a DETACH REQUEST to the CN 1j-03 to disconnect from the CN 1j-03.

[0206] In operation 1j-15, the UE 1j-01 can perform cell (re)selection to establish a connection with a specific cell.

[0207] In operation 1j-20, after the UE 1j-01 performs an RRC connection process, the UE 1g-01 can transmit a NAS message (e.g., ATTACH REQUEST) including a manufacturer-based UE capability ID or a parameter requesting a new PLMN-based UE capability ID (or an indicator indicating that the UE capability ID does not exist or is invalid) to the CN 1j-03 to which the corresponding base station is connected.

[0208] In operation 1j-25, the CN 1j-03 that has received the NAS message can perform a process for setting NAS security (authentication).

[0209] In operation 1j-30, CN 1j-03 may notify gNB 1j-02 that CN 1j-03 does not have the UE capabilities of UE1j-01, and deliver an INITIAL CONTEXT SETUP REQUEST message (NAS message) requesting UE capabilities to gNB 1h-02. In the foregoing operation, when CN 1j-03 has a manufacturer-based UE capability ID received from UE 1j-01, CN 1j-03 may transmit the manufacturer-based UE capability ID together. In the foregoing operation, gNB 1j-02 may identify the manufacturer-based UE capability ID received from CN 1j-03, and when gNB 1h-02 has UE capability information corresponding to the identifier and can thus restore the UE capabilities, gNB 1j-02 may notify CN 1h-03 of this. Thereafter, the UE capability request process may be omitted.

[0210] In operation 1j-35, gNB 1j-02 may identify the UE capability request received from CN 1j-03 and trigger a UE capability request.

[0211] That is, in operation 1j-40, gNB 1j-02 may transmit a UE capability request message (UECapabilityEnquiry) to UE 1j-01, which includes the RAT type and filtering information for requesting UE capabilities. The RRC message may also include an indicator indicating whether UE 1j-01 is capable of providing a UE capability ID.

[0212] In operation 1j-45, when NG gNB 1j-02 has received an indicator indicating whether UE 1j-01 is capable of providing a UE capability ID (or an indicator indicating that the manufacturer-based UE capability ID is invalid) and has a PLMN-based UE capability ID corresponding to the UE capability request including the RAT type and filtering information, UE 1j-01 may deliver a UE capability information message (UECapabilityInformation) including the corresponding identifier to gNB 1j-02. However, when UE 1j-01 does not have a PLMN-based UE capability ID corresponding to the request of gNB1j-02, in operation 1j-45, UE 1j-01 may configure the UE capabilities by reflecting the RAT type and filtering information as in the existing UE capability reporting process, and transmit a UE capability information message (UECapabilityInformation) to gNB1j-02.

[0213] The following embodiments may be embodiments of a process corresponding to a case where in operation 1j-45, UE 1j-01 reports UE capabilities because UE 1j-01 does not have the corresponding PLMN-based UE capability ID for the UE capabilities.

[0214] In operation 1j-50, UE 1j-01 may know that gNB 1j-02 does not have UE capabilities corresponding to the manufacturer-based UE capability ID provided by UE 1j-01. UE 1j-01 may know that UE 1j-01 can receive a PLMN-based UE capability ID corresponding to the UE capabilities transmitted to gNB 1j-02 because UE 1j-01 has already transmitted its UE capabilities to gNB 1j-02. Thus, in the corresponding operation, UE 1j-01 may store the UE capability information transmitted in operation 1j-45 in the internal buffer (memory) of UE 1i-01, and store the RAT type and filtering information related to the UE capability requested by gNB 1i-02. In addition, UE 1j-01 may store the registered PLMN information of the serving cell connected in the system information SIB1 received from the corresponding serving cell. In summary, in operation 1j-50, UE 1j-01 may store the PLMN information, RAT type and filtering information, and the reported UE capabilities as a group.

[0215] In operation 1j-55, gNB 1j-02 may transmit the UECapabilityInformation message received from UE 1j-01 to CN 1j-03, and may carry the corresponding UE capabilities, including filtering information, in different containers of different RAT types.

[0216] In operation 1j-60, CN 1j-03 may identify the UE capabilities received in the foregoing operations, and when there is a PLMN-based UE capability ID corresponding to the UE capabilities for the filtering information and the requested RAT type reported by UE 1j-01 in the stored table, CN 1j-03 may assign the corresponding identifier as the PLMN-based UE capability ID. However, when the reported UE capabilities are new capabilities that CN 1j-03 does not have, CN 1j-03 may assign a new PLMN-based UE capability ID.

[0217] In operation 1j-65, CN 1j-03 may transmit the PLMN-based UE capability ID assigned corresponding to the UE capabilities reported by UE 1j-02 to UE 1j-01 via a NAS message (e.g., ATTACH RESPONSE). The foregoing message may include index information for indicating the UE capabilities indicated by the identifier or the RAT type and filtering information corresponding to the UE capabilities.

[0218] The reason for the corresponding operation is that operations 1j-40 and 1j-45 can be continuously executed instead of being executed once. For example, gNB 1i-02 can transmit an NR UE capability request including RAT type and filtering information to UE 1j-40 in operation 1i-45, and receive the corresponding UE capability from UE 1j-01, and then repeat operation 1j-40 again to request EN-DC UE capability and receive the UE capability report corresponding to operation 1j-45. In this case, CN 1j-03 may have to allocate a PLMN-based UE capability ID for each of the two continuously received UE capabilities, so that index information for distinguishing UE capabilities can be included and transmitted (for example, the first UE capability report can be set to 1 and the second UE capability report can be set to 2), or the filtering information can be transmitted together.

[0219] In operation 1j-60, the method of allocating a PLMN-based UE capability ID performed by CN 1i-03 can apply different operations according to network implementation. For example, in an embodiment, a UE capability report of a specific UE can be received, and when the number of UE reports providing the same UE capability as the corresponding UE capability is greater than a predetermined threshold N, the corresponding UE capability can be specified, and a PLMN-based UE capability ID can be allocated. That is, an algorithm may be required, in which not only a few UE capability reports are used to allocate a specific PLMN-based UE capability ID.

[0220] In operation 1j-70, UE 1j-01 can map the PLMN-based UE capability ID received from CN 1j-03 in operation 1i-65 to the UE capability storage group reported and stored by UE 1j-01 in operation 1j-50, and store them newly. That is, UE 1j-01 can store the PLMN-based UE capability ID, registered PLMN information, RAT type and filtering information, and the reported UE capability in one group, and then use the PLMN-based UE capability ID allocated to represent the UE capability. In the foregoing operation, the number of PLMN-based UE capability IDs that UE 1j-01 can store may be limited, and while storing a set number of PLMN-based UE capability IDs, when UE 1j-01 needs to store UE capabilities for a new PLMN-based UE capability ID, the previously stored PLMN-based UE capability ID and the corresponding UE capability group can be deleted, and can be updated with new values. In the foregoing operation, the information of the same PLMN can be left, and the information of different PLMNs can be deleted.

[0221] In operation 1j-75, CN 1j-03 may send the PLMN-based UE capability ID sent to UE 1j-01 to gNB 1j-02 via an N1 message.

[0222] In operation 1j-80, gNB 1j-02 may store the PLMN-based UE capability ID, registered PLMN information, RAT type and filtering information, and reported UE capabilities as a group based on the received PLMN-based UE capability ID, the UE capabilities received in operation 1j-45, and the RAT type and filtering information sent to UE 1j-01 in operation 1i-40. Thereafter, when UE 1j-01 uses the PLMN-based UE capability ID assigned to represent UE capabilities, gNB 1j-02 that has received the PLMN-based UE capability ID may not trigger a UE capability request.

[0223] In the above embodiment, when transmitting the UE capability ID via an initial NAS message, the UE has several UE capability IDs (manufacturer-based UE capability ID and PLMN-based UE capability ID), and the UE may transmit all the UE capability IDs. Alternatively, the UE may only report the representative manufacturer-based UE capability ID.

[0224] Figure 1k is a view according to an embodiment for describing operations of allocating and updating a PLMN-based UE capability identifier. More specifically, Figure 1k is a view according to an embodiment for describing the overall operations of allocating and updating a PLMN-based UE capability identifier.

[0225] In operation 1k-05, the UE may camp on a certain serving cell and switch to the RRC connected state.

[0226] In operation 1k-10, after connecting to the corresponding cell, the UE may send the UE capability ID that the UE has to the core network associated with the base station via an NAS message (e.g., an INITIAL ATTACH message). The ID may include a manufacturer-based UE capability ID and a PLMN-based UE capability ID, and when no PLMN-based UE capability ID is assigned, the ID may include a manufacturer-based UE capability ID.

[0227] In operation 1k-15, when the core network or the base station fails to recover the UE capabilities for the UE capability ID sent from the UE, the UE may receive a message requesting a UE capability report via the base station and perform a UE capability report as a response.

[0228] In operation 1k-20, the UE may store the UE capabilities, registered PLMN information, and filtering information (including RAT type) reported in the previous operation.

[0229] In operation 1k-25, when the UE receives a PLMN-based UE capability ID from the core network, the UE may map the stored UE capabilities to the received PLMN-based UE capability ID and manage them in the foregoing operation. That is, in subsequent operations, the representation of the UE capabilities may be replaced with the assigned PLMN-based UE capability ID.

[0230] In operation 1k-30, the UE may determine whether the UE capabilities for the assigned PLMN-based UE capability ID have changed.

[0231] When the UE capabilities have changed, in operation 1k-35, the UE may perform a DETACH or RRC release procedure with the corresponding serving cell and the core network.

[0232] In operation 1k-40, after the UE performs an RRC connection procedure with a specific cell again, the UE may request a new PLMN-based UE capability ID (notifying that the previous PLMN-based UE capability ID must be updated). The foregoing request may be performed in an operation of transmitting a NAS message to the core network after the RRC connected state, and the process of being assigned a new PLMN-based UE capability ID may include 1k-15 to 1k-25.

[0233] When the UE capabilities have changed in operation 1k-30, the UE may apply the PLMN-based UE capability ID assigned in operation 1k-25 to use it instead of the UE capabilities. That is, the UE may transmit the PLMN-based UE capability ID in the RRC IDLE or a new UE capability report request.

[0234] Figure 1l It is a block diagram of the structure of a UE according to an embodiment.

[0235] Reference Figure 1l , a UE according to an embodiment may include a transceiver 1l-05, a controller 1l-10, a multiplexer / demultiplexer 1l-15, various upper layer processors 1l-20 and 1l-25, and a control message processor 1l-30.

[0236] The transceiver 1l-05 receives data and specific control signals through the forward channel carrier of the serving cell, and transmits data and predetermined control signals through the backward channel of the serving cell. When multiple serving cells are set, the transceiver 1l-05 uses the multiple serving cells to perform data transmission and reception as well as control signal transmission and reception. The multiplexer / demultiplexer 1l-15 multiplexes the data generated in the upper layer processors 1l-20 and 1l-25 or the control message processor 1l-30, or demultiplexes the data received from the transceiver 1l-05, so as to transmit the multiplexed or demultiplexed data to the upper layer processors 1l-20 and 1l-25 or the control message processor 1l-30.

[0237] The control message processor 1l-30 can send and receive control messages from the base station and perform necessary operations. Here, the necessary operations can include functions such as processing control messages such as RRC messages and MAC CE, reporting CBR measurement values, and receiving RRC messages for resource pools and UE operations. The upper layer processors 1l-20 and 1l-25 can represent DRB devices and can be configured for each service. Each of the upper layer processors 1l-20 and 1l-25 can process the data generated in user services such as File Transfer Protocol (FTP) or Voice over Internet Protocol (VoIP) to transmit the data to the multiplexer / demultiplexer 1l-15, or process the data transmitted from the multiplexer / demultiplexer 1l-15 to transmit the processed data to the upper layer service application.

[0238] The controller 1l-10 recognizes scheduling instructions received through the transceiver 1l-05, such as UL grants, and controls the transceiver 1l-05 and the multiplexer / demultiplexer 1l-15 to perform UL transmission with appropriate transmission resources at appropriate time points. At the same time, in the above embodiments, the UE includes multiple blocks, and each of these blocks performs different functions, but this is only an embodiment and is not limited thereto. For example, the controller 1I-10 can perform the functions performed by the demultiplexer 1I-15.

[0239] Figure 1m is a block diagram of the structure of a base station according to an embodiment.

[0240] Reference Figure 1m Figure, the base station can include a transceiver 1m-05, a controller 1m-10, a multiplexer / demultiplexer 1m-20, a control message processor 1m-35, various upper layer processors 1m-25 and 1m-30, and a scheduler 1m-15.

[0241] The transceiver 1m-05 can send data and a certain control signal via the DL carrier, and receive data and a certain control signal via the UL carrier. When multiple carriers are configured, the transceiver 1m-05 can use the above-mentioned multiple carriers to perform data transmission and reception as well as control signal transmission and reception. The multiplexer / demultiplexer 1m-20 can multiplex the data generated in the upper layer processors 1m-25 and 1m-30 or the control message processor 1m-35, or demultiplex the data received from the transceiver 1m-05, so as to transfer the multiplexed or demultiplexed data to the upper layer processors 1m-25 and 1m-30, the control message processor 1m-35 or the controller 1m-10. The control message processor 1m-35 can generate a message to be passed to the UE and pass the generated message to the lower layer under the control of the controller. Each of the upper layer processors 1m-25 and 1m-30 can be configured for each UE and each service, and process the data generated in user services such as FTP or VoIP to transfer the data to the multiplexer / demultiplexer 1m-20, or process the data transferred from the multiplexer / demultiplexer 1m-20 to transfer the processed data to the upper layer service application. The scheduler 1m-15 can allocate transmission resources to the UE at an appropriate time point, considering the buffer state of the UE, the channel state and the active time of the UE, and control the transceiver to process the signal sent from the UE or send a signal to the UE.

[0242] According to an embodiment, in the NR system, in order to reduce the signaling overhead of UE capability reporting in the process where the UE receives a request for UE capability from the base station and reports the UE capability to the base station, the identifier information specified for UEs with the same UE capability can be used to replace the UE capability reporting. In particular, the method according to the above embodiment may include a UE identifier access method based on the manufacturer and a UE identifier access method based on the PLMN. The foregoing embodiment may provide an overall operation of a method for using a PLMN-based UE identifier to transfer UE capabilities.

[0243] According to an embodiment of the present disclosure, when the base station instructs the NR UE to report the UE capability for MR-DC, the UE capability reporting process performed by the UE can be clearly defined. Therefore, the UE can accurately transfer its capability, and the base station can accurately understand the capability of the UE and provide appropriate configuration information.

[0244] Embodiments of the present disclosure may propose a method for solving the following problem, where when the UE changes the secondary cell group while performing a handover to a target cell for dual connection with a serving cell in the NR system, the RRC connection completion message transmission of the target cell and the random access operation of the secondary cell group may overlap.

[0245] According to an embodiment, when the UE changes the secondary cell group while performing a handover to a target cell for dual connectivity with the serving cell, the transmission of the RRC connection completion message of the target cell and the random access operation of the secondary cell group may not overlap and may be performed sequentially.

[0246] Figure 2a shows the structure of an LTE system according to an embodiment. Refer to Figure 2a , the radio access network in the LET system may include next-generation base stations (eNBs, Node Bs, or base stations) 2a-05, 2a-10, 2a-15, and 2a-20, a mobility management entity (MME) 2a-25, and a serving gateway (S-GW) 2a-30. A user equipment (UE or terminal) 2a-35 may be connected to an external network through eNBs 2a-05 to 2a-20 and the S-GW 2a-30.

[0247] In Figure 2a , the eNBs 2a-05 to 2a-20 may correspond to existing Node Bs in UMTS. The eNB may be connected to the UE 2a-35 through a radio channel and play a more complex role than the existing Node B. In the LTE system, each user traffic and real-time services such as VoIP are provided through a shared channel, which requires a device for collecting UE state information such as buffer status, available transmit power status, channel status, etc., and performing scheduling based on the state information. An example of such a device may be the eNBs 2a-05 to 2a-20. Generally, one eNB may control multiple cells. For example, to implement a transmission rate of 100 Mbps, the LTE system may use, for example, OFDM as a wireless connection scheme in a 20 MHz bandwidth. Similarly, AMC may be used, where the modulation scheme and channel coding rate are determined based on the UE's channel state. The S-GW 2a-30 may be a device for providing data bearers and generating or removing data bearers under the control of the MME 2a-25. The MME is responsible for various control functions and the UE's mobility management function and may be connected to multiple BSs.

[0248] Figure 2b shows the radio protocol architecture in an LTE system according to an embodiment.

[0249] Refer to Figure 2b , the radio protocol of the LTE system may include PDCPs 2b-05 and 2b-40, RLCs 2b-10 and 2b-35, and MACs 2b-15 and 2b-30 at the UE and the eNB, respectively. The PDCPs 2b-05 and 2b-40 may be responsible for IP header compression / decompression, etc. The main functions of the PDCP may be summarized as follows:

[0250] - Header compression and decompression (only ROHC)

[0251] - Transmission of user data

[0252] - Sequentially deliver upper layer PDUs during the PDCP re - establishment procedure for RLC AM

[0253] - For split bearers in DC (RLC AM only): PDCP PDU delivery for transmission and PDCP PDU re - ordering for reception

[0254] - Repeatedly detect lower layer SDUs during the PDCP re - establishment procedure of RLC AM

[0255] - For RLC AM, re - send PDCP SDUs during handover, and for split bearers in DC, re - send PDCP PDUs during the PDCP data recovery procedure

[0256] - Encryption and decryption

[0257] - Timer - based SDU discard in the uplink

[0258] RLC 2b - 10 and 2b - 35 can reconstruct PDCP PDUs into appropriate sizes and perform ARQ operations. The main functions of RLC can be summarized as follows:

[0259] - Transmission of upper layer PDUs

[0260] - Error correction via ARQ (only for AM data transmission)

[0261] - Concatenation, segmentation, and reassembly of RLC SDUs (only for UM and AM data transmission)

[0262] - Re - segmentation of RLC data PDUs (only for AM data transmission)

[0263] - Re - ordering of RLC data PDUs (only for UM and AM data transmission)

[0264] - Repeated detection (only for UM and AM data transmission)

[0265] - Protocol error detection (only for AM data transmission)

[0266] - RLC SDU discard (only for UM and AM data transmission)

[0267] - RLC re - establishment

[0268] The MAC layers 2b-15 and 2b-30 can be connected to multiple RLC layer entities configured in a UE, multiplex RLC PDUs into MAC PDUs, and demultiplex MAC PDUs into RLC PDUs. The main functions of the MAC can be summarized as follows:

[0269] - Mapping between logical channels and transport channels

[0270] - Multiplexing MAC SDUs belonging to one or different logical channels into a TB delivered to the physical layer on a transport channel / Demultiplexing MAC SDUs from a TB delivered from the physical layer on a transport channel

[0271] - Scheduling information reporting

[0272] - Error correction by HARQ

[0273] - Priority handling between the logical channels of a UE

[0274] - Priority handling between UEs by means of dynamic scheduling

[0275] - MBMS service identification

[0276] - Transmission format selection

[0277] - Padding

[0278] The physical (PHY) layers 2b-20 and 2b-25 can perform channel coding and modulation of the upper layer data, and convert the data into OFDM symbols to transmit the OFDM symbols through the radio channel, or demodulate the OFDM symbols received through the radio channel and perform channel decoding of the OFDM symbols to deliver the OFDM symbols to the upper layer.

[0279] For further error correction in the physical layer, HARQ is used, where the receiving end sends 1 bit as information on whether a packet sent from the sending end has been received. This information can be referred to as HARQ ACK / NACK information. The DL HARQ ACK / NACK information for UL transmission is transmitted through the PHICH physical channel, and the UL HARQ ACK / NACK information for DL transmission is transmitted through the PUCCH or PUSCH physical channels.

[0280] Meanwhile, the aforementioned PHY layer may include one frequency / carrier or multiple frequencies / carriers, and the technique for simultaneously setting multiple frequencies for using them may be referred to as CA. CA may alternatively use a primary carrier and one or more secondary carriers instead of using one carrier for communication between a terminal (or UE) and a base station (E-UTRAN NodeB or eNB). By using CA, the transmission volume can be innovatively increased to approximately the number of secondary carriers. Meanwhile, in LTE, the cell using the primary carrier in the base station may be referred to as a PCell, and the cell using the secondary carrier may be referred to as an SCell.

[0281] Although not shown, the RRC layer may exist on the PDCP layer of the UE and the eNB, respectively. The aforementioned RRC layer may exchange configuration control messages related to RRC connection and measurement.

[0282] Figure 2c The structure of a next-generation mobile communication system according to an embodiment is shown.

[0283] Reference Figure 2c , as shown in the figure, the radio access network of a next-generation mobile communication (hereinafter, NR or 5G) system may include an NR NB 2c-10 and an NR core network (CN) or a next-generation (NG) CN2c-05. A new radio user equipment (NR UE or UE) 2c-15 may access an external network through the NR NB 2c-10 and the NR CN 2c-05.

[0284] In Figure 2cIn this context, NR NB 2c-10 can correspond to the eNB in the existing LTE system. NR NB 2c-10 can be connected to NR UE 2c-15 via a radio channel and can provide services that are more advanced than those of the existing Node B. In the next-generation mobile communication system, all user traffic is served via a shared channel, which requires a device to collect status information such as the buffer status, available transmission power status, and channel status of the UE and perform scheduling, where NR NB 2c-10 can be responsible for these functions. One NR NB 2c-10 can typically control multiple cells. To achieve ultra-high-speed data transmission compared to the LTE system, the next-generation mobile communication system can have a maximum bandwidth that is larger than the existing maximum bandwidth and can adopt beamforming technology in addition to OFDM as the radio access technology. Similarly, AMC can be used, where the modulation scheme and channel coding rate are determined based on the channel status of the UE. NR CN2c-05 can perform functions such as mobility support, bearer setup, QoS setup, etc. NR CN 2c-05 can be a device that not only performs mobility management functions for the UE but also performs various control functions and can be connected to multiple base stations. The next-generation mobile communication system can also cooperate with the existing LTE system, where NR CN 2c-05 can be connected to MME 2c-25 via a network interface. MME 2c-25 can be connected to eNB 2c-30, which is an existing base station.

[0285] Figure 2d Fig. shows the radio protocol architecture of a next-generation mobile communication system according to an embodiment.

[0286] Refer to Figure 2d , the radio protocol of the next-generation mobile communication system can include NRSDAP 2d-01 and 2d-45, NR PDCP 2d-05 and 2d-40, NR RLC 2d-10 and 2d-35, and NR MAC 2d-15 and 2d-30 at the UE and NR gNB, respectively.

[0287] The main functions of NR SDAP 2d-01 and 2d-45 can include some of the following functions:

[0288] - Transmission of user plane data

[0289] - Mapping between QoS flows and DRBs for both DL and UL

[0290] - Marking the QoS flow ID in both DL and UL packets

[0291] - Reflective QoS flow to DRB mapping of UL SDAP PDUs

[0292] For the foregoing SDAP layer entity, via the RRC message, it is possible to set, for each PDCP layer entity, each bearer, or each logical channel, whether the UE uses the header of the SDAP layer entity or the function of the SDAP layer entity, and when the SDAP header is set, the network attached storage (NAS) QoS reflection configuration 1-bit indicator (NAS reflected QoS) and the AS QoS reflection configuration 1-bit indicator (AS reflected QoS) can be used to indicate that the UE can update or reconfigure the QoS flows of the UL and DL and the mapping information regarding the data bearer. The SDAP header may include QoS flow ID information indicating QoS. The QoS information can be used as data processing priority information, scheduling information, etc. to support smooth services.

[0293] The main functions of NR PDCP 2d-05 and 2d-40 may include some of the following functions:

[0294] - Header compression and decompression: (only ROHC)

[0295] - Transmission of user data

[0296] - In-sequence delivery of upper layer PDUs

[0297] - Out-of-sequence delivery of upper layer PDUs

[0298] - PDCP PDU reordering for reception

[0299] - Duplicate detection of lower layer SDUs

[0300] - Retransmission of PDCP SDUs

[0301] - Encryption and decryption

[0302] - Timer-based SDU discard in the uplink

[0303] In this document, the reordering of the NR PDCP entity may involve the function of reordering the PDCP PDUs received from the lower layer in sequence based on the PDCP SN and delivering the data to the upper layer in the reordered sequence. The reordering function of the NR PDCP device may include at least one of the following: delivering the data to the upper layer in the reordered sequence; delivering the data immediately regardless of the order; recording the PDCP PDUs lost due to reordering; reporting the status of the lost PDCP PDUs to the transmission side or requesting retransmission of the lost PDCP PDUs.

[0304] The main functions of NR RLC 2d-10 and 2d-35 may include some of the following functions:

[0305] - Transmission of upper layer PDUs

[0306] -In-sequence delivery of upper-layer PDUs

[0307] -Out-of-sequence delivery of upper-layer PDUs

[0308] -Error correction via HARQ

[0309] -Concatenation, segmentation, and reassembly of RLC SDUs

[0310] -Resegmentation of RLC data PDUs

[0311] -Reordering of RLC data PDUs

[0312] -Duplicate detection

[0313] -Protocol error detection

[0314] -RLC SDU discard

[0315] -RLC re-establishment

[0316] In this document, the in-sequence delivery function of the NR RLC entity may involve the function of delivering RLC SDUs received from the lower layer to the upper layer in sequence. When an RLC SDU is segmented into several RLC SDUs and then several RLC SDUs are received, the in-sequence delivery of the NR RLC entity may include the function of reassembling and delivering several RLC SDUs.

[0317] The in-sequence delivery of the NR RLC entity may include at least one of the following: reordering the received RLC PDUs based on the RLC sequence number (SN) or PDCPSN; reordering records of PDCP PDUs lost due to reordering; reporting the status of lost PDCP PDUs to the transmission side or requesting retransmission of lost PDCP PDUs. When there are any lost RLC SDUs, the in-sequence delivery function of the NR RLC entity may include the function of delivering the RLC SDUs before the lost RLC SDU to the upper layer in sequence.

[0318] The in-sequence delivery function may further include: the function of delivering, when a certain timer expires, all the RLC SDUs received before the start of the timer to the upper layer in sequence, despite the presence of RLC SDUs, or the function of delivering all the RLC SDUs received up to the current time when a certain timer expires, despite the presence of RLC SDUs. The NR RLC entity may process RLC PDUs in the order of reception (arrival order, independent of the order of SNs), and transmit the RLC PDUs to the PDCP entity in an out-of-sequence manner. For segmentation, the NR RLC entity may receive segments stored in the buffer or segments to be received later, may reconstruct the segments into a complete RLC PDU, may process the RLC PDU, and may transmit the RLC PDU to the PDCP entity. The NR RLC layer may not include the concatenation function, and the concatenation function may be performed in the NR MAC layer or may be replaced by the multiplexing function of the NR MAC layer.

[0319] In this document, the out-of-sequence delivery of the NR RLC entity may include the function of immediately delivering the RLC SDUs received from the lower layer to the upper layer regardless of the order. The out-of-sequence delivery function of the RLC entity may include at least one of the following: the function of reassembling and delivering multiple RLC SDUs when an original RLC SDU is divided into multiple RLC SDUs to be received; or the function of recording the lost RLC PDUs by storing and reordering the RLC SNs or PDCP SNs of the received RLC PDUs.

[0320] NR MAC 2d-15 and 2d-30 may be connected to multiple NR RLC layer entities configured in a UE, and the main functions of the NR MAC may include some of the following functions:

[0321] - Mapping between logical channels and transmission channels

[0322] - Multiplexing / demultiplexing of MAC SDUs

[0323] - Scheduling information reporting

[0324] - Error correction by HARQ

[0325] - Priority handling between logical channels of a UE

[0326] - Priority handling between UEs by means of dynamic scheduling

[0327] - MBMS service identification

[0328] - Transmission format selection

[0329] - Padding

[0330] The NR PHY layers 2d-20 and 2d-25 can perform channel coding and modulation of the upper layer data, convert the data into OFDM symbols to transmit the OFDM symbols via a radio channel, or demodulate the OFDM symbols received via the radio channel, and perform channel decoding of the OFDM symbols to deliver the OFDM symbols to the upper layer.

[0331] Figure 2e is a flowchart according to an embodiment for describing a case where a secondary cell group change and a handover request are performed by one RRC message.

[0332] In an embodiment of the present disclosure, it may be assumed that when a handover occurs, especially in the MR-DC context, a change of a secondary node (SN) is indicated and thus occurs simultaneously. In an embodiment, the overall UE operation may be described, in which the handover can be performed without problems in such a context. That is, in the method according to an embodiment, when a handover and an SN change are indicated simultaneously, the random access to the master node (MN) to be changed and the random access to the SN to be changed can be sequentially performed to reduce the interruption between the two nodes. Figure 2e is an overall flowchart in the foregoing context and can be directly applied to an embodiment. In addition, in Figure 2e for example, even in the MR-DC context, it may be assumed to be connected to an NR cell as an MN especially to a 5G core network. In this case, the SN may be an NR cell or an LTE cell. That is, in the embodiment described with reference to Figure 2e NR-E-UTRA (NE)-DC and NR-DC can be applied.

[0333] The UE 2e-01 can be connected to the serving cell of the source MN 2e-02, communicate with the source SN 2e-03 via the DC setup, and may trigger a handover due to a specific reason. The specific reason may include a case where the channel measurement value in an adjacent cell is higher than a specific threshold when compared with the current serving cell.

[0334] In operation 2e-10, the serving cell of the source MN 2e-02 that has determined the handover can transmit a handover request message to request a handover to the cell of the target MN 2e-05 to which the handover is to be performed. When requesting a handover, an SN change process (SCG change) can be performed. This may include that the change from the source SN 2e-03 to another target SN 2e-04 needs to be processed simultaneously with the handover.

[0335] In operation 2e-15, the target MN 2e-05 that has received the handover request can transmit an SN addition request message to the target SN 2e-04.

[0336] In operation 2e-20, the target SN 2e-04 may transmit a corresponding response message.

[0337] In operation 2e-25, the target MN 2e-05 may transmit a handover request confirmation message to the source MN 2e-02 in response to the handover.

[0338] In operation 2e-30, the source MN 2e-02 that has received the handover request confirmation message may transmit an SN release message to the source SN 2e-03 in which the DC is set.

[0339] In operation 2e-35, the source SN 2e-02 may transmit an SN release request confirmation message regarding the SN release request.

[0340] In operation 2e-40, the source MN 2e-02 that has confirmed that the handover can be performed through the foregoing process may transmit an RRCReconfiguration message to the UE 2e-01 to indicate the handover request. The RRCReconfiguration message may include the configuration of the new primary cell group and secondary cell group through the handover, and these configurations may include a reconfigurationWithSync field that includes the parameters required for synchronization due to the handover and the parameters required for the handover operation.

[0341] The information configured in the foregoing reconfigurationWithSync field may include serving cell configuration information regarding the PCell and PSCell, radio network temporary identifier (RNTI), T304 timer, etc., and RACH resource information regarding the random access channel (RACH) resources capable of performing random access.

[0342] The UE 2e-01 that has received the RRCReconfiguration message indicating both the handover and the SN change in operation 2e-40 may perform a random access to the target MN 2e-05 in operation 2e-45.

[0343] In operation 2e-50, the UE 2e-01 may transmit an RRCReconfigurationComplete message to the target MN 2e-05 and indicate the completion of the handover.

[0344] After completing the foregoing operations, in operation 2e-55, the UE may perform a random access procedure for target SN 2e-04. However, when operations 2e-45 to 2e-55 reflect the current standard, handover and SN change may occur simultaneously, such that the random access to target MN 2e-05 and the random access to target SN 2e-04 may be interrupted. Alternatively, the transmission of the RRCReconfigurationComplete message to target MN 2e-05 and the random access to target SN 2e-04 may be interrupted.

[0345] In this case, the expected random access operation is not correctly performed, such that the handover process may not be perfectly executed. That is, in an embodiment of the present disclosure, when handover and SN change are indicated simultaneously, the random access to the MN to be changed and the random access to the SN to be changed may be sequentially performed to reduce the interruption between the two nodes. Reference will be made to Figure 2f and Figure 2g for a more detailed description of the existing UE operations and the detailed UE operations according to the embodiment.

[0346] In operation 2e-60, target MN 2e-05 may transmit an SN reconfiguration complete message indicating reconfiguration completion to target SN 2e-04 based on the response indicating that the handover and SN change are completed received from UE 2e-01 in operation 2e-50.

[0347] In operation 2e-65, source SN 2e-03 may transmit the amount of data transmitted from the source SN in the secondary RAT to source MN 2e-02.

[0348] In operation 2e-70, source MN 2e-03 may transmit the secondary RAT report transmitted from the SN to the access and mobility management function (AMF) 2e-07.

[0349] In operation 2e-75, source MN 2e-03 may transmit the data packet received from the UE before the handover and the sequence number information of the transmitted data packet to target MN 2e-05.

[0350] In operation 2e-80, source MN 2e-03 may transmit the DL data packet received through the user plane function (UPF) 2e-06 to target MN 2e-05.

[0351] In operation 2e-85, target SN 2e-05 may transmit a message requesting to change the data path of the user plane to AMF 2e-07.

[0352] In operation 2e-90, the AMF 2e-07 may send a bearer information modification to the UPF 2e-06.

[0353] In operation 2e-95, the UPF 2e-06 may create and indicate a new MN-terminated bearer path.

[0354] In operation 2e-100, the UPF 2e-06 may send the newly created SN-terminated bearer path to the target SN 2e-04.

[0355] In operation 2e-105, the AMF 2e-07 may notify the target MN 2e-05 of the completion of the path change. In operation 2e-110, the target MN 2e-05 may request the release of the UE context from the source MN 2e-02. And in operation 2e-115, the source MN 2e-02 may confirm the request and request the release of the UE context from the source SN 2e-03.

[0356] Figure 2f is a flowchart for describing the existing UE operations in the case where a secondary cell group change and a handover request are performed by one RRC message according to an embodiment.

[0357] In reference Figure 2f In the described embodiment, for the case where a handover occurs especially in the MR-DC context and at the same time a change of the SN is indicated, the current standard can be described. In the method according to the embodiment, in the above handover context, the random access to the target MN and the random access to the target SN are performed simultaneously. That is, in the method according to the embodiment, when a handover and an SN change are indicated simultaneously, the random access to the MN to be changed and the random access to the SN to be changed are performed simultaneously, resulting in an interruption between the two nodes.

[0358] In operation 2f-05, the UE may receive an RRCReconfiguration message indicating a handover from the source MN to the target MN. The RRCReconfiguration message may include the configuration of the newly configured primary cell group and secondary cell group through the handover, and these configurations may include a reconfigurationWithSync field, which includes the parameters required for synchronization due to the handover and the parameters required for the handover operation. The information configured in the above reconfigurationWithSync field may include the serving cell configuration information about the PCell and PSCell, RNTI, T304 timer, etc., and the RACH resource information about the RACH resources capable of performing random access.

[0359] When receiving the above RRCReconfiguration message, subsequent procedures may consider the internal operations of the UE.

[0360] In operation 2f-10, the UE may identify the masterCellGroup configuration information of the MN included in the received RRCReconfiguration message and apply this information. That is, in the corresponding operation, the UE may execute the ReconfigurationwithSync configuration information, which is the configuration information for switching to the target MN, and this operation may include starting the received T304 timer (dedicated to the PCell).

[0361] In operation 2f-15, when the MasterKeyUpdate field for the MN is included in the above RRCReconfiguration message, the UE may perform the operation of updating the key KgNB for MN encryption.

[0362] In operation 2f-20, when the mrdc-SecondarySellGroup configuration is included in the above RRCReconfiguration message, that is, included in the configuration information of the SCG in the DC context (NR SCG or LTE SCG configuration is possible), the masterCellGroup configuration information for the SN included therein may be applied. That is, the RRCReconfiguration message may include the configuration information of the SN changed during the handover, and the T304 timer dedicated to the PSCell of the SN may be started when executing the ReconfigurationwithSync configuration information.

[0363] In 2f-25, when the sk-Counter information is included in the configuration information of the foregoing SCG, the UE may perform a key update operation on the SN.

[0364] In operation 2f-30, when there is a corresponding configuration, the UE may execute additional configuration information, such as radiobearerConfig and measConfig for the SN.

[0365] In operation 2f-35, the UE may generate an SN-dedicated RRCReconfigurationComplete message as a response to the reconfiguration information dedicated to the SN in the configured MR-DC and include it in the nr-SCG-Response (or eutra-SCG-Response) message.

[0366] In operation 2f-40, the UE can identify the reconfiguration information of the remaining MN and execute this information. That is, in the corresponding operation, when there is a corresponding configuration, additional configuration information such as radiobearerConfig and measConfig for the MN can be executed.

[0367] In operation 2f-45, the UE can generate an RRCReconfigurationComplete message as a response to the received RRCReconfiguration message and transmit this message to the lower layer. The above RRCReconfigurationComplete message can include an nr-SCG-Response (or eutra-SCG-Response) generated in octet form in operation 2f-35. In the above operation, the UE can be instructed via RRC to perform a random access to the target PCell and perform a random access to the target PCell.

[0368] In operation 2f-50, the UE can be instructed via RRC to perform a random access to the target PSCell and perform a random access to the target PSCell. However, operation 2f-45 and operation 2f-50 can be performed simultaneously, and the random access to the target PCell and the random access to the target PSCell can be interrupted.

[0369] In an embodiment, when the random access preamble transmission can occur simultaneously in the MN and the SN, the MN can maintain the transmission power with priority, but in this case, the SN may be affected. That is, there may be a loss in power transmission, so the UL coverage may not be guaranteed, resulting in a failure in random access. When the transmission of the RRCReconfigurationComplete message and the transmission of the SN random access preamble occur simultaneously, the SN random access preamble can have priority, such that the transmission of the RRCReconfigurationComplete that must be sent to the target MN may fail or be delayed. This is because the priority of the PRACH transmission is higher than that of the PUSCH transmission.

[0370] After completing the foregoing random access procedures for the target MN and the target SN, in operation 2f-55, the target MN MAC layer can indicate the completion of the random access and stop the T304 timer of the PCell.

[0371] Similarly, in operation 2f-60, the target SN MAC layer can indicate the completion of the random access and stop the T304 timer of the PSCell.

[0372] Figure 2gIt is a flowchart for describing a method of sequentially performing random access to a primary cell group and a secondary cell group in a case where a secondary cell group change and a handover request are performed through one RRC message according to an embodiment.

[0373] In an embodiment of the present disclosure, for a case where a handover occurs especially in an MR-DC context and at the same time a change of SN is indicated, the current standard can be described. In the method according to the embodiment, in the above handover context, random access to the target MN and random access to the target SN are sequentially performed. According to the embodiment, when a handover and an SN change are indicated simultaneously, random access to the MN to be changed and random access to the SN to be changed can be sequentially performed, thereby reducing the interruption between the two nodes.

[0374] In operation 2g-05, the UE may receive an RRCReconfiguration message indicating a handover from the source MN to the target MN. The RRCReconfiguration message may include configuration of a newly configured primary cell group and secondary cell group through the handover, and these configurations may include a reconfigurationWithSync field, which includes parameters required for synchronization due to the handover and parameters required for the handover operation. Information configured in the above reconfigurationWithSync field may include serving cell configuration information about the PCell and PSCell, RNTI, T304 timer, etc., and RACH resource information about RACH resources capable of performing random access.

[0375] When the above RRCReconfiguration message is received, the subsequent process may be regarded as an internal operation of the UE.

[0376] In operation 2g-10, the UE may identify the masterCellGroup configuration information of the MN included in the received RRCReconfiguration message and apply the information. That is, in the corresponding operation, the UE may execute the ReconfigurationwithSync configuration information, which is the configuration information for handover to the target MN, and this operation may include starting the received T304 timer (dedicated to the PCell).

[0377] In operation 2g-15, when a MasterKeyUpdate field for the MN is included in the above RRCReconfiguration message, the UE may perform an operation of updating the key KgNB for MN encryption.

[0378] In operation 2g-20, when the mrdc-SecondarySellGroup configuration is included in the above RRCReconfiguration message, that is, included in the configuration information of the SCG in the DC context (NR SCG or LTE SCG configuration is possible), the masterCellGroup configuration information for the SN included therein can be applied. That is, the above RRCReconfiguration message can include the configuration of the SN to be changed in the handover, so that the UE can execute the ReconfigurationwithSync configuration information. However, in the corresponding operation, even when the T304 timer dedicated to the SN's PSCell is included, the UE may not execute this timer. This is because when performing sequential random access operations on the target MN and the target SN, there is a time interval between the start of the T304 timer of the PSCell and the actual start of the random access in the target SN, thus defeating the purpose of the T304 operation to determine the UE operation by determining the time required for the handover process.

[0379] Although described in the following operations, in the embodiments of the present disclosure, after the handover process (random access) is completed in the target MN, random access can be started in the target SN, so that when the random access starts in the target SN, the T304 timer of the PSCell can be started.

[0380] In 2g-25, when the sk-Counter information is included in the configuration information of the foregoing SCG, the UE can perform a key update operation on the SN.

[0381] In operation 2g-30, when there is a corresponding configuration, additional configuration information such as radiobearerConfig and measConfig for the SN can be executed.

[0382] In operation 2g-35, the UE can generate an SN-dedicated RRCReconfigurationComplete message as a response to the SN-dedicated reconfiguration information in the configured MR-DC and include it in the nr-SCG-Response (or eutra-SCG-Response) message.

[0383] In operation 2g-40, the UE can identify the reconfiguration information of the remaining MN and execute this information. That is, in the corresponding operation, when there is a corresponding configuration, additional configuration information such as radiobearerConfig and measConfig for the MN can be executed.

[0384] In operation 2g-45, the UE may generate an RRCReconfigurationComplete message as a response to the received RRCReconfiguration message and transmit the message to the lower layer. The above RRCReconfigurationComplete message may include an nr-SCG-Response (or eutra-SCG-Response) generated in octet form in operation 2g-35. In the foregoing operation, the UE may be instructed via RRC to perform random access to the target PCell and perform random access to the target PCell.

[0385] In operation 2g-50, the UE may determine whether the RRCReconfigurationComplete message transmitted to the target MN has been completely transmitted and then perform the next operation. That is, in operation 2g-50, the UE may receive a Layer 2 ACK confirmation (ACK) message regarding the RRCReconfigurationComplete message and then perform the corresponding operation, followed by the process described below.

[0386] After receiving the Layer 2 ACK message regarding the RRCReconfigurationComplete message, in operation 2g-55, the UE may start the T304 timer of the PSCell.

[0387] In operation 2g-60, the UE may perform random access to the target PSCell. Through the above sequential process, random access and handover operations for the target MN and the target SN may not be performed simultaneously, thereby preventing interruption of the random access preamble transmission of the MN and the SN.

[0388] After completing the foregoing random access process for the target MN and the target SN, in operation 2g-65, the target MN MAC layer may indicate the completion of random access and stop the T304 timer of the PCell.

[0389] Similarly, in operation 2f-70, the target SN MAC layer may indicate the completion of random access and stop the T304 timer of the PSCell.

[0390] Figure 2h is a block diagram of the structure of a UE according to an embodiment.

[0391] Reference Figure 2h , the UE may include an RF processor 2h-10, a baseband processor 2h-20, a memory 2h-30, and a controller 2h-40.

[0392] The RF processor 2h-10 can perform functions such as transmitting and receiving signals through a wireless channel, such as frequency band conversion and amplification. That is, the RF processor 2h-10 can up-convert the baseband signal provided by the baseband processor 2h-20 into an RF band signal, transmit the RF band signal through an antenna, and down-convert the RF band signal received through the antenna into a baseband signal. For example, the RF processor 2h-10 can include a transmit filter, a receive filter, an amplifier, a mixer, an oscillator, a digital-to-analog converter (DAC), and an analog-to-digital converter (ADC), etc. Although one antenna is shown in the foregoing figures, the UE may also include multiple antennas. The RF processor 2h-10 can include multiple RF chains. The RF processor 2h-10 can perform beamforming. For beamforming, the RF processor 2h-10 can adjust the phase and magnitude of the signals transmitted and received through multiple antennas or antenna elements. The RF processor can also perform MIMO and can receive multiple layers when performing MIMO operations.

[0393] The baseband processor 2h-20 can perform the conversion between the baseband signal and the bit stream according to the physical layer standard of the system. For example, during data transmission, the baseband processor 2h-20 can generate complex symbols by encoding and modulating the transmitted bit stream. During data reception, the baseband processor 2h-20 can recover the received bit stream by demodulating and decoding the baseband signal provided by the RF processor 2h-10. For example, when using OFDM, during data transmission, the baseband processor 2h-20 can generate complex symbols by encoding and modulating the transmitted bit stream, map the complex symbols to subcarriers, and construct OFDM symbols by IFFT and CP insertion. In addition, during data reception, the baseband processor 2h-20 divides the baseband signal provided by the RF processor 2h-10 into OFDM symbol units, recovers the signals mapped to subcarriers by FFT, and recovers the received bit stream by demodulating and decoding.

[0394] The baseband processor 2h-20 and the RF processor 2h-10 can transmit and receive signals as described above. Therefore, the baseband processor 2h-20 and the RF processor 2h-10 can also be represented by a transmitter, a receiver, a transceiver, or a communicator. In addition, at least one of the baseband processor 2h-20 and the RF processor 2h-10 can include multiple communication modules to support multiple different radio access technologies.

[0395] In addition, at least one of the baseband processor 2h-20 and the RF processor 2h-10 may include a plurality of communication modules for processing signals in different frequency bands. For example, different radio access technologies may include wireless LAN (e.g., IEEE 802.11) and cellular networks (e.g., LTE), etc. In addition, different frequency bands may include super high frequency (SHF, e.g., 2. NRHz, NRhz) bands and millimeter wave (mm-wave, e.g., 60 GHz) bands.

[0396] The memory 2h-30 may store data, such as basic programs for UE operation, application programs, and configuration information, etc. In particular, the memory 2h-30 may store information related to the second connection node to perform wireless communication by using the second wireless connection technology. The memory 2h-30 provides the stored data in response to a request from the controller 2h-40.

[0397] The controller 2h-40 may control the overall operation of the UE. For example, the controller 2h-40 may transmit and receive signals through the baseband processor 2h-20 and the RF processor 2h-10. The controller 2h-40 may record and read data in the memory 2h-30. To this end, the controller 2h-40 may include at least one processor. For example, the controller 2h-40 may include a communication processor (CP) for performing communication control and an application processor (AP) for controlling the upper layer such as application programs.

[0398] Figure 2i is a block diagram of the structure of a base station according to an embodiment.

[0399] Reference Figure 2i , the base station may include an RF processor 2i-10, a baseband processor 2i-20, a backhaul communicator 2i-30, a memory 2i-40, and a controller 2i-50.

[0400] The RF processor 2i-10 may perform functions such as frequency band conversion and amplification for transmitting and receiving signals through a wireless channel. That is, the RF processor 2i-10 may up-convert the baseband signal provided by the baseband processor 2i-20 into an RF band signal, transmit the RF band signal through an antenna, and down-convert the RF band signal received through the antenna into a baseband signal. For example, the RF processor 2i-10 may include a transmit filter, a receive filter, an amplifier, a mixer, an oscillator, a DAC, and an ADC, etc. Although Figure 2iOnly one antenna is shown, but RF processor 2i-10 may also include multiple antennas. RF processor 2i-10 may include multiple RF chains. RF processor 2i-10 may perform beamforming. For beamforming, RF processor 2i-10 may adjust the phase and magnitude of signals transmitted and received through multiple antennas or antenna elements. RF processor 2h-10 may perform downlink MIMO operations by transmitting one or more layers.

[0401] Baseband processor 2i-20 may perform conversion between baseband signals and bitstreams according to the physical layer standards of the first radio connection technology. For example, during data transmission, baseband processor 2i-20 may generate complex symbols by encoding and modulating the transmitted bitstream. During data reception, baseband processor 2i-20 may recover the received bitstream by demodulating and decoding the baseband signal provided by RF processor 2i-10. For example, when using OFDM, during data transmission, baseband processor 2i-20 may generate complex symbols by encoding and modulating the transmitted bitstream, map the complex symbols to subcarriers, and construct OFDM symbols by IFFT and CP insertion. Additionally, during data reception, baseband processor 2i-20 divides the baseband signal provided by RF processor 2i-10 into OFDM symbol units, recovers the signals mapped to subcarriers by FFT, and recovers the received bitstream by demodulating and decoding. Baseband processor 2i-20 and RF processor 2i-10 may transmit and receive signals as described above. Thus, baseband processor 2i-20 and RF processor 2i-10 may also be represented by a transmitter, receiver, transceiver, communicator, or wireless communicator.

[0402] Backhaul communicator 2i-30 may provide an interface to perform communication with other nodes in the network. That is, backhaul communicator 2i-30 may convert the bitstream to be sent to another node (e.g., secondary base station, core network, etc.) into a physical signal, and convert the physical signal received from another node into a bitstream.

[0403] Memory 2i-40 may store data, such as basic programs, application programs, and configuration information for the operation of the primary base station, etc. Specifically, memory 2i-40 may store information about the bearers allocated to connected UEs and the measurement results reported by the connected UEs. Memory 2i-40 may store information that is the criterion for determining whether to provide or stop multiple connections to the UE. Memory 2i-40 provides the stored data at the request of controller 2i-50.

[0404] The controller 2i-50 can control the overall operation of the master base station. For example, the controller 2i-50 can send and receive signals through the baseband processor 2i-20 and the RF processor 2i-10 or through the backhaul communicator 2i-30. The controller 2i-50 can record and read data in the memory 2i-40. To this end, the controller 2i-50 can include at least one processor.

[0405] Meanwhile, the embodiments disclosed in this specification and the drawings are provided to easily describe the present disclosure and help understand the present disclosure, and are not intended to limit the scope of the present disclosure. In other words, it will be obvious to those of ordinary skill in the art that various changes can be made without departing from the scope of the present disclosure. In addition, the embodiments of the present disclosure can be implemented in combination. For example, the base station and the UE can be managed by combining some parts of an embodiment of the present disclosure with another embodiment of the present disclosure. Although the embodiments of the present disclosure have been described based on the frequency division duplex (FDD) LTE system, modifications based on the technical spirit of the embodiments can also be performed in other systems such as the time division duplex (TDD) LTE system, 5G or NR system.

Claims

1. A communication method for a user equipment (UE) in a wireless communication system, the communication method comprising: Receiving, from a base station, a UE capability information request message, the UE capability information request message including radio access technology (RAT) type information associated with at least one of New Radio (NR), Evolved Universal Terrestrial Radio Access Network (EUTRA), or EUTRA-NR; and Sending, to the base station, a non-access stratum (NAS) message including a UE capability identifier, wherein the UE capability identifier is allocated by a core network via NAS signaling and is a PLMN-specific UE capability identifier among a plurality of PLMN-specific UE capability identifiers, and wherein a plurality of PLMN-specific UE capability identifiers including a predetermined number of PLMN-specific UE capability identifiers are stored in the UE.

2. The communication method according to claim 1, wherein the UE capability identifier is configured based on the RAT type information.

3. The communication method according to claim 1, further comprising storing a PLMN-specific UE capability identifier, Among them, and deleting a previously stored PLMN-specific UE capability identifier when the number of the plurality of PLMN-specific UE capability identifiers exceeds the predetermined number.

4. The communication method according to claim 1 further comprises: Sending a NAS message including a manufacturer-specific UE capability identifier when the UE is not allocated with the PLMN-specific UE capability identifier.

5. The communication method according to claim 1, further comprising: Determining whether the capability information of the UE has changed; and Based on the determined result, sending a message including information indicating that a new PLMN-specific UE capability identifier needs to be updated.

6. The communication method according to claim 1, wherein, The UE capability identifier corresponds to UE capability information, and wherein mapping information between the UE capability information and the UE capability identifier is stored.

7. A communication method for an entity in a core network in a wireless communication system, the communication method comprising: Sending, to a user equipment UE, a UE capability information request message including radio access technology (RAT) type information associated with at least one of New Radio (NR), Evolved Universal Terrestrial Radio Access Network (EUTRA), or EUTRA-NR; and Receiving, via a base station, a non-access stratum (NAS) message including a UE capability identifier, wherein the UE capability identifier is allocated by the core network via NAS signaling and is a PLMN-specific UE capability identifier among a plurality of PLMN-specific UE capability identifiers, and wherein a plurality of PLMN-specific UE capability identifiers including a predetermined number of PLMN-specific UE capability identifiers are stored in the UE.

8. The communication method according to claim 7, wherein The UE capability identifier is configured based on the RAT type information.

9. The communication method according to claim 7, wherein, The UE capability identifier corresponds to UE capability information, and wherein mapping information between the UE capability information and the UE capability identifier is stored.

10. The communication method according to claim 7 further comprises: In a case where the UE is not allocated a PLMN-specific UE capability identifier, receive a NAS message including a manufacturer-specific UE capability identifier.

11. The communication method according to claim 7 further includes: Receive a message based on a determination of whether the UE's capability information has changed, the message including information indicating a need to update a new PLMN-specific UE capability identifier.

12. A user equipment (UE) in a wireless communication system, the UE comprising: A transceiver; And At least one processor coupled to the transceiver and configured to: Receive a UE capability information request message from a base station, the UE capability information request message including radio access technology (RAT) type information associated with at least one of New Radio (NR), Evolved Universal Terrestrial Radio Access Network (EUTRA), or EUTRA-NR, and Send a non-access stratum (NAS) message including a UE capability identifier to the base station, Wherein the UE capability identifier is allocated by a core network via NAS signaling and is a PLMN-specific UE capability identifier included in a plurality of PLMN-specific UE capability identifiers, and Wherein a plurality of PLMN-specific UE capability identifiers including a predetermined number of PLMN-specific UE capability identifiers are stored in the UE.

13. An entity in a core network in a wireless communication system, the entity comprising: A transceiver; And At least one processor coupled to the transceiver and configured to: Send a UE capability information request message to a user equipment (UE), the UE capability information request message including radio access technology (RAT) type information associated with at least one of New Radio (NR), Evolved Universal Terrestrial Radio Access Network (EUTRA), or EUTRA-NR, and Receive a non-access stratum (NAS) message including a UE capability identifier via a base station, Wherein the UE capability identifier is allocated by the core network via NAS signaling and is a PLMN-specific UE capability identifier included in a plurality of PLMN-specific UE capability identifiers, and Wherein a plurality of PLMN-specific UE capability identifiers including a predetermined number of PLMN-specific UE capability identifiers are stored in the UE.

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