Method and apparatus for performing communication in wireless communication system

Abstract

A method and an apparatus for performing communication in a wireless communication system are provided. A method performed by a first terminal in a wireless communication system includes: transmitting a sidelink radio resource control (RRC) message including configuration information related to a sidelink to a second terminal; and receiving a response message of a sidelink RRC message from the second terminal as a response to the sidelink RRC message, where the response message includes a first response message or a second response message, and where the second response message is received in a case where the second terminal does not conform to the configuration information.

Description

[0001] This application is a divisional application of an invention patent application with an application date of January 9, 2020, Chinese application number 202080020569.8, and invention name “Method and device for performing communication in a wireless communication system”. Technical Field

[0002] The present disclosure relates generally to wireless communication systems, and more particularly, to methods and apparatus for performing communications in wireless communication systems. Background Art

[0003] In order to meet the growing demand for wireless data communication volume due to the commercialization of the fourth generation (4G) system and the increase of multimedia services, an improved fifth generation (5G) communication system or a pre-5G communication system is being developed. A "5G communication system" or a "pre-5G communication system" may also be referred to as a "super 4G network communication system" or a "post-Long Term Evolution (LTE) system".

[0004] In order to increase data transmission rate, 5G communication systems are being developed to be implemented in ultra-high frequency bands (millimeter waves (mmWave)) (for example, a frequency band of 60 GHz).

[0005] In order to reduce the path loss of radio waves in such ultra-high frequency bands and increase the transmission distance of radio waves, various technologies for 5G communication systems are being discussed and studied, such as beamforming, massive multiple-input multiple-output (MIMO), full-dimensional MIMO (FD-MIMO), array antennas, analog beamforming, and massive antennas.

[0006] In order to improve the system network performance of the 5G communication system, various technologies have been developed, such as evolved small cells, advanced small cells, cloud radio access networks (RAN), ultra-dense networks, device-to-device communication (D2D), wireless backhaul, mobile networks, cooperative communication, coordinated multi-point (CoMP), interference cancellation. For the 5G communication system, other technologies have been developed, such as frequency shift keying (FSK) and quadrature amplitude modulation (QAM) (FQAM) and sliding window superposition coding (SWSC) as a hybrid of 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.

[0007] The Internet of Things (IoT) is where distributed devices (such as objects) exchange information with each other to process information.

[0008] The Internet of Everything (IoE) technology has also emerged, in which technologies related to the IoT are combined with technologies for processing big data, such as through connection to cloud servers. To implement the IoT, various technical components are used, such as sensor technology, wired / wireless communication and network infrastructure, service interface technology, security technology, etc.

[0009] In recent years, technologies including sensor networks for connecting objects, machine-to-machine (M2M) communication, machine type communication (MTC), etc. have been studied. In the IoT environment, smart Internet technology (IT) services can be provided to collect and analyze data obtained from interconnected objects to create new value in human life. As existing information technology technologies and various industries merge and combine with each other, IoT can be applied to various fields such as smart homes, smart buildings, smart cities, smart cars or connected cars, smart grids, healthcare, smart appliances, high-quality medical services, etc.

[0010] Various attempts are being made to apply 5G communication systems to IoT networks. For example, technologies related to sensor networks, M2M communications, MTC, etc. are being implemented by using 5G communication technologies including beamforming, MIMO, array antennas, etc. The application of the above-mentioned cloud RAN as a big data processing technology can be an example of the fusion of 5G communication technology and IoT technology. Summary of the invention

[0011] Solution to the problem

[0012] An aspect of the present disclosure is to provide a method and apparatus for performing full configuration in a wireless communication system.

[0013] One aspect of the present disclosure provides a method performed by a first terminal in a wireless communication system, the method comprising: sending a sidelink radio resource control (RRC) message including configuration information related to a sidelink to a second terminal; and receiving a response message to the sidelink RRC message from the second terminal as a response to the sidelink RRC message, wherein the response message includes a first response message or a second response message, and wherein the second response message is received if the second terminal cannot comply with the configuration information.

[0014] One aspect of the present disclosure provides a first terminal in a wireless communication system, the terminal comprising: a transceiver; and at least one processor, coupled to the transceiver and configured to: send a sidelink radio resource control (RRC) message including configuration information related to a sidelink to a second terminal, and receive a response message to the sidelink RRC message from the second terminal as a response to the sidelink RRC message, wherein the response message includes a first response message or a second response message, and wherein the second response message is received if the second terminal cannot comply with the configuration information. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] The above and other aspects, features, and advantages of certain embodiments of the present disclosure will become more apparent from the following description in conjunction with the accompanying drawings, in which:

[0016] Figure 1A An LTE system according to an embodiment is shown;

[0017] Figure 1B shows a radio protocol architecture in an LTE system according to an embodiment;

[0018] Figure 1C A next generation mobile communication system according to an embodiment is shown;

[0019] Figure 1D shows a radio protocol architecture of a next generation mobile communication system according to an embodiment;

[0020] Figure 1E is a signal flow diagram illustrating a process in which a user equipment (UE) switches a radio resource control (RRC) connected mode to an RRC idle mode when an evolved Node B (eNB) releases a connection with the UE, and a process in which the UE establishes a connection with the eNB to switch the RRC idle mode to the RRC connected mode according to an embodiment;

[0021] Figure 1F A mobile communication system according to an embodiment is shown;

[0022] Figure 1G is a signal flow diagram illustrating a UE operation procedure when a UE in an RRC connected mode receives an RRCReconfiguration message or an RRCResume message from a next generation Node B (gNB) according to an embodiment;

[0023] Figure 1H is a flowchart illustrating the operation of a UE according to an embodiment;

[0024] Fig. 1I is a flow chart illustrating the operation of a base station according to an embodiment;

[0025] Figure 2A is a signal flow diagram illustrating a process in which a UE switches from an RRC connected mode to an RRC idle mode when an eNB releases a connection with the UE, and a process in which the UE establishes a connection with the eNB to switch from the RRC idle mode to the RRC connected mode according to an embodiment;

[0026] Figure 2B is a signal flow diagram illustrating a process in which a UE in RRC connected mode performs measurement when an eNB or gNB provides a measurement configuration applicable in RRC connected mode to the UE according to an embodiment;

[0027] Figure 2C is a signal flow diagram illustrating a process in which a UE in RRC connected mode performs measurement when an eNB or gNB provides a measurement configuration applicable in RRC connected mode to the UE according to an embodiment;

[0028] Figure 2D is a flowchart illustrating a process in which a UE switches an RRC connected mode to an RRC idle mode when a base station releases a connection with the UE according to an embodiment, and illustrating an operation of the UE when the UE selects a Global System for Mobile Communications (GSM) or Universal Mobile Telecommunications System (UMTS) Terrestrial Radio Access Network (UTRAN) cell in the RRC idle mode;

[0029] Figure 3A illustrates vehicle-to-everything (V2X) communication in a mobile communication system according to an embodiment;

[0030] Figure 3B is a signal flow diagram illustrating a unicast link establishment procedure for New Radio (NR) V2X Side Link (SL) support according to an embodiment;

[0031] Figure 3C is a signal flow diagram illustrating a process of performing NR V2X SL unicast communication via a pre-configured transmit resource pool and / or receive resource pool in an inter-UE scheduled resource allocation mode according to an embodiment;

[0032] Figure 3D is a signal flow diagram illustrating a process of performing NR V2X SL unicast communication via a pre-configured transmit resource pool and / or receive resource pool in an inter-UE autonomous resource selection mode according to an embodiment;

[0033] Figure 3E shows a UE according to an embodiment; and

[0034] Figure 3F A base station according to an embodiment is shown. DETAILED DESCRIPTION

[0035] Another aspect of the present disclosure is to provide a method and apparatus for performing over-the-air measurement of H1 / H2 events in a wireless communication system.

[0036] Another aspect of the present disclosure is to provide a method and apparatus for supporting vehicle communication using preconfigured resources in a wireless communication system.

[0037] According to one aspect of the present disclosure, an operation method for a terminal in a wireless communication system is provided. The operation method includes: receiving a radio resource control (RRC) message from a base station, the RRC message including an indicator about a full configuration process; when at least one data radio bearer (DRB) corresponding to a protocol data unit (PDU) session about the terminal is not included in a DRB addition list included in the RRC message, identifying whether an indicator indicating switching is included in the RRC message; and based on the result of the identification, sending a message to an upper layer indicating the release of user plane resources about the PDU session.

[0038] According to another aspect of the present disclosure, a terminal in a wireless communication system is provided. The terminal includes a transceiver; and at least one processor configured to: receive a radio resource control (RRC) message from a base station, the RRC message including an indicator about a full configuration process; when at least one data radio bearer (DRB) corresponding to a protocol data unit (PDU) session about the terminal is not included in a DRB addition list included in the RRC message, identify whether an indicator indicating switching is included in the RRC message; and based on the result of the identification, send a message to an upper layer indicating the release of user plane resources about the PDU session.

[0039] Hereinafter, the operating principle of the present disclosure will be described with reference to the accompanying drawings. When describing the present disclosure, when the relevant well-known functions or configurations may unnecessarily obscure the essence of the present disclosure, their detailed description may be omitted. In addition, the terms used below are defined in consideration of the functions in the present disclosure, and may have different meanings depending on the intentions of the user or operator, customer. Therefore, these terms should be defined based on the description of the entire specification.

[0040] Throughout the present disclosure, the expression "at least one of a, b, and c" means only a, only b, only c, a and b, a and c, b and c, all of a, b, and c, or variations thereof.

[0041] Examples of the terminal may include UE, a mobile station (MS), a cellular phone, a smart phone, a computer, and a multimedia system capable of performing a communication function.

[0042] A controller may also be called a processor.

[0043] A layer (or layer arrangement) may also be referred to as an entity.

[0044] Here, the terms used to identify access nodes, terms representing network entities, terms representing messages, terms representing interfaces between network entities, terms representing various types of identification information, etc. are exemplified for convenience of description. Therefore, the terms used in the present disclosure are not limited, and other terms representing objects with the same technical meaning may be used.

[0045] In the following, for the convenience of description, the present disclosure uses the terms and names defined by the 3rd Generation Partnership Project Long Term Evolution (3GPP LTE) standard. However, the present disclosure is not limited to these terms and names and can be equally applied to systems that comply with other standards. For the convenience of description, an evolved Node B (eNB) may be interchangeably referred to as a next generation Node B (gNB). That is, a base station described as an eNB may also indicate a gNB.

[0046] Figure 1A An LTE system according to an embodiment is shown.

[0047] refer to Figure 1A , a radio access network (RAN) of an LTE system includes evolved base stations (e.g., evolved Node B (eNB), Node B (NB) 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 UE (or terminal) 1a-35 can access an external network via the eNB 1a-05, 1a-10, 1a-15 or 1a-20 and the S-GW 1a-30.

[0048] The eNB 1a-05, 1a-10, 1a-15 or 1a-20 may correspond to an existing NB of UMTS. The eNB 1a-05, 1a-10, 1a-15 or 1a-20 may be connected to the UE 1a-35 through a radio channel, and may perform complex functions compared to existing base stations. In an LTE system, all user traffic including real-time services such as Voice over Internet Protocol (VoIP) may be provided via a shared channel. Therefore, an entity that schedules UEs by collecting status information such as a buffer status, an available transmission power status, and a channel status of the UE 1a-35 is used, and the eNB 1a-05, 1a-10, 1a-15 or 1a-20 may operate as the entity.

[0049] A single eNB can typically control multiple cells. For example, an LTE system can use a radio access technology such as orthogonal frequency division multiplexing (OFDM) at a bandwidth of 20 MHz to achieve a data rate of 100 Mbps. Adaptive modulation and coding (AMC) can be used to determine the modulation scheme and channel coding rate according to the channel state of the UE 1a-35.

[0050] S-GW 1a-30 may provide a data bearer and may configure or release a data bearer under the control of MME 1a-25. MME 1a-25 is an entity for performing a mobility management function and various control functions for UE 1a-35 and may be connected to eNBs 1a-05, 1a-10, 1a-15, and 1a-20.

[0051] Figure 1B A radio protocol architecture in an LTE system according to an embodiment is shown.

[0052] refer to Figure 1B , the radio protocol architecture of the LTE system may include the Packet Data Convergence Protocol (PDCP) layers 1b-05 and 1b-40, the Radio Link Control (RLC) layers 1b-10 and 1b-35, and the Medium Access Control (MAC) layers 1b-15 and 1b-30 for the UE and eNB, respectively. The PDCP layer 1b-05 or 1b-40 is responsible for IP header compression / decompression, etc. The main functions of the PDCP layer 1b-05 or 1b-40 can be summarized as follows:

[0053] -Header compression and decompression: Robust Header Compression (ROHC) only

[0054] -Transfer of user data

[0055] - For RLC AM, in-sequence delivery of upper layer PDUs during PDCP reestablishment

[0056] - For split bearers in Dual Connectivity (DC) (supporting RLC Acknowledged Mode (AM) only): PDCP PDU routing for transmission and PDCP PDU reordering for reception

[0057] - For RLC AM, duplicate detection of lower layer service data units (SDUs) during PDCP re-establishment

[0058] - For RLC AM, retransmission of PDCP SDUs at handover and retransmission of PDCP PDUs during PDCP data recovery for split bearers in DC

[0059] -Encryption and decryption

[0060] - Timer-based SDU discard in uplink

[0061] The RLC layer 1b-10 or 1b-35 may perform, for example, an automatic repeat request (ARQ) operation by reconfiguring the PDCP PDU to an appropriate size. The main functions of the RLC layer 1b-10 or 1b-35 may be summarized as follows:

[0062] -Data transfer (transfer of upper layer PDU)

[0063] - Error correction via ARQ (applicable only to AM data transfer)

[0064] - RLC SDU concatenation, segmentation and reassembly (only for unacknowledged mode (UM) and AM data delivery)

[0065] - Re-segmentation of RLC data PDU (only for AM data delivery)

[0066] - Reordering of RLC data PDUs (only for UM and AM data delivery)

[0067] - Duplicate detection (for UM and AM data delivery only)

[0068] -Protocol error detection (for AM data transfer only)

[0069] -RLC SDU discard (only for UM and AM data delivery)

[0070] -RLC reconstruction

[0071] The MAC layer 1b-15 or 1b-30 is connected to multiple RLC layers configured for a single UE, and can multiplex RLC PDUs into MAC PDUs and demultiplex RLC PDUs from MAC PDUs. The main functions of the MAC layer 1b-15 or 1b-30 can be summarized as follows:

[0072] - Mapping between logical channels and transport channels

[0073] - Multiplexing / demultiplexing MAC SDUs belonging to one or more different logical channels into / from a transport block (TB) transmitted to / from the physical layer on a transport channel

[0074] -Dispatch information report

[0075] - Error correction via Hybrid Automatic Repeat Request (HARQ)

[0076] - Priority handling between logical channels of a UE

[0077] - Prioritization between UEs through dynamic scheduling

[0078] -Multimedia Broadcast Multicast Service (MBMS) service identification

[0079] -Transmission format selection

[0080] -filling

[0081] The physical (PHY) layer 1b-20 or 1b-25 can encode and modulate the upper layer data channel into OFDM symbols and send the OFDM symbols through the radio channel, or demodulate the OFDM symbols received through the radio channel, channel-decode the OFDM symbols and transmit the OFDM symbols to the upper layer.

[0082] Figure 1C A next generation mobile communication system according to an embodiment is shown.

[0083] refer to Figure 1C , the RAN of a next generation mobile communication system (e.g., a new radio (NR) or 5G system) may include a new radio node B (NR NB) or a new radio next generation node B (NR gNB) 1c-10 and a new radio core network (NR CN) or a next generation core network (NG CN) 1c-05. A new radio user equipment (NR UE) or UE 1c-15 may access an external network via the NR gNB 1c-10 and the NR CN 1c-05.

[0084] NR gNB 1c-10 can correspond to the eNB of the existing LTE system. NR gNB 1c-10 is connected to NR UE 1c-15 through a radio channel and can provide superior services compared to existing NBs. In the next generation mobile communication system, all user traffic can be provided via a shared channel. Therefore, an entity that schedules UEs by collecting status information such as the buffer status, available transmission power status, and channel status of UE 1c-15 is used, and NR gNB1c-10 can operate as the entity. A single NR gNB can control multiple cells. In the next generation mobile communication system, a bandwidth larger than the maximum bandwidth of LTE can be given to achieve the current ultra-high data rate, and beamforming technology can be added to radio access technologies such as OFDM. In addition, AMC can be used to determine the modulation scheme and channel coding rate according to the channel status of UE 1c-15.

[0085] NR CN 1c-05 can perform functions such as mobility support, bearer establishment, and quality of service (QoS) establishment. NR CN 1c-05 is an entity for performing mobility management functions and various control functions for UE 1c-15, and can be connected to multiple NR gNB 1c-10. The next-generation mobile communication system can cooperate with the existing LTE system, and NR CN 1c-05 can be connected to MME 1c-25 through a network interface. MME 1c-25 can be connected to the existing eNB 1c-30.

[0086] Figure 1D A radio protocol architecture of a next generation mobile communication system according to an embodiment is shown.

[0087] refer to Figure 1D The radio protocol architecture of the next-generation mobile communication system includes the NR Service Data Adaptation Protocol (SDAP) layers 1d-01 and 1d-45, NR PDCP layers 1d-05 and 1d-40, NR RLC layers 1d-10 and 1d-35, and NR MAC layers 1d-15 and 1d-30 for UE and NR gNB, respectively.

[0088] The main functions of NR SDAP layers 1d-01 and 1d-45 may include some of the following functions:

[0089] -Transmission of user plane data

[0090] - Mapping between QoS flows and data radio bearers (DRBs) for downlink (DL) and uplink (UL)

[0091] - Marking QoS flow identifier (ID) in DL and UL packets

[0092] - Mapping of Reflective QoS Flow to DRB for UL SDAP PDU

[0093] Regarding the SDAP layer, the UE can receive settings regarding whether to use the header of the SDAP layer or the functions of the SDAP layer for each PDCP layer, each bearer, or each logical channel via an RRC message for the SDAP layer. When the SDAP header is configured, the UE can indicate the non-access stratum (NAS) reflected QoS1 bit indicator and the access stratum (AS) reflected QoS1 bit indicator of the SDAP header to update or reconfigure the mapping information about the data bearers and QoS flows for UL and DL. The SDAP header may include a QoS flow ID indicating QoS. QoS information can be used as data processing priority information, scheduling information, etc. for supporting smooth services.

[0094] The main functions of the NR PDCP layer 1d-05 or 1d-40 may include some of the following functions:

[0095] -Header compression and decompression: ROHC only

[0096] -Transfer of user data

[0097] - In-sequence delivery of upper layer PDUs

[0098] - Out-of-order delivery of upper layer PDUs

[0099] -PDCP PDU reordering for reception

[0100] - Duplicate detection of lower layer SDU

[0101] -Retransmission of PDCP SDU

[0102] -Encryption and decryption

[0103] - Timer-based SDU discard in uplink

[0104] The reordering function of the NR PDCP layer 1d-05 or 1d-40 may include a function of reordering the PDCP PDU received from the lower layer based on the PDCP sequence number (SN). The reordering function of the NR PDCP layer 1d-05 or 1d-40 may include a function of transmitting the reordered data to the upper layer in sequence, or a function of transmitting the reordered data immediately without considering the sequence, may include a function of recording the lost PDCP PDU by reordering the PDCP PDU, may include a function of reporting the status information of the lost PDCP PDU to the transmitter, or may include a function of requesting retransmission of the lost PDCP PDU.

[0105] The main functions of the NR RLC layer 1d-10 or 1d-35 may include at least some of the following functions:

[0106] - Delivery of upper layer PDU

[0107] - In-sequence delivery of upper layer PDUs

[0108] - Out-of-order delivery of upper layer PDUs

[0109] - Error correction via ARQ

[0110] - RLC SDU splicing, segmentation and reassembly

[0111] - Re-segmentation of RLC data PDU

[0112] - Reordering of RLC data PDUs

[0113] - Duplicate detection

[0114] -Protocol error detection

[0115] -RLC SDU discarded

[0116] -RLC reconstruction

[0117] In-sequence delivery of NR RLC layer 1d-10 or 1d-35 may include a function of delivering an RLC SDU received from a lower layer to an upper layer in sequence. When an RLC SDU is segmented into multiple RLC SDUs and received, in-sequence delivery of NR RLC layer 1d-10 or 1d-35 may include a function of reassembling multiple RLC SDUs and delivering the RLC SDUs.

[0118] The in-sequence transmission of NR RLC layer 1d-10 or 1d-35 may include a function of reordering the received RLC PDU based on the RLC SN or PDCP SN, a function of recording the lost RLC PDU by reordering the RLC PDU, a function of reporting the status information of the lost RLC PDU to the transmitter, or a function of requesting retransmission of the lost RLC PDU.

[0119] In-sequence delivery of NR RLC layer 1d-10 or 1d-35 may include a function of, when there is a lost RLC SDU, delivering only the RLC SDUs preceding the lost RLC SDU in sequence to an upper layer entity. In-sequence delivery of NR RLC layer 1d-10 or 1d-35 may include a function of, when a certain timer expires, delivering in sequence to an upper layer entity all RLC SDUs received before the start of the timer despite the presence of lost RLC SDUs, or a function of, when a certain timer expires, delivering in sequence to an upper layer entity all RLC SDUs received until the current time despite the presence of lost RLC SDUs.

[0120] The NR RLC layer 1d-10 or 1d-35 can process the RLC PDU in the order of reception without considering the sequence number and deliver the RLC PDU to the PDCP entity out of order (out-of-order delivery), and in the case of segmentation, the fragments stored in the buffer or to be received later can be received and delivered to the NR PDCP layer 1d-05 or 1d-40.

[0121] When the NR RLC layer 1d-10 or 1d-35 receives the fragments, the NR RLC layer 1d-10 or 1d-35 may reassemble the fragments received or stored in the buffer into a whole RLC PDU and transmit the RLC PDU to the NR PDCP layer 1d-05 or 1d-40. The NR RLC layer 1d-10 or 1d-35 may not have a splicing function, and the splicing function may be performed by the NR MAC layer 1d-15 or 1d-30, or replaced by a multiplexing function of the NR MAC layer 1d-15 or 1d-30.

[0122] Out-of-order delivery of the NR RLC layer 1d-10 or 1d-35 may mean a function of immediately delivering the RLC SDU received from the lower layer to the upper layer out of order. The out-of-order delivery of the NR RLC layer 1d-10 or 1d-35 may include a function of reassembling a plurality of RLC SDUs segmented from the RLC SDU and transmitting the RLC SDU when the segmented RLC SDU is received. The out-of-order delivery of the NR RLC layer 1d-10 or 1d-35 may include a function of storing the RLC SN or PDCP SN of the received RLC PDU and recording the lost RLC PDU by sorting the RLC PDU.

[0123] The NR MAC layer 1d-15 or 1d-30 may be connected to a plurality of NR RLC layers 1d-10 or 1d-35 configured for a single UE, and main functions of the NR MAC layer 1d-15 or 1d-30 may include at least some of the following functions:

[0124] - Mapping between logical channels and transport channels

[0125] -Multiplexing / demultiplexing of MAC SDU

[0126] -Dispatch information report

[0127] - Error correction through HARQ

[0128] - Priority handling between logical channels of a UE

[0129] - Priority handling between UEs through dynamic scheduling

[0130] -MBMS service logo

[0131] -Transmission format selection

[0132] -filling

[0133] The PHY layer 1d-20 or 1d-25 can encode and modulate the upper layer data channel into OFDM symbols and send the OFDM symbols through the radio channel, or demodulate the OFDM symbols received through the radio channel, channel-decode the OFDM symbols and transmit the OFDM symbols to the upper layer.

[0134] Figure 1E is a signal flow diagram illustrating a process in which a UE switches an RRC connected mode to an RRC idle mode when an eNB releases a connection with the UE, and a process in which the UE establishes a connection with the eNB to switch the RRC idle mode to an RRC connected mode according to an embodiment.

[0135] refer to Figure 1E When a UE that sends or receives data in RRC connected mode does not send or receive data due to a specific reason or at a specific time, the eNB sends an RRCConnectionReleas message to the UE to switch to RRC idle mode (step 1e-01). When generating data to be sent, a UE that has not currently established a connection (hereinafter referred to as an idle mode UE) can perform an RRC connection establishment procedure with the eNB.

[0136] The UE establishes reverse transmission synchronization with the eNB through a random access procedure, and sends an RRCConnectionRequest message to the eNB (step 1e-05). The RRCConnectionRequest message may include the UE identifier, establishment cause, and the like.

[0137] The eNB sends an RRCConnectionSetup message so that the UE establishes an RRC connection (step 1e-10). The RRCConnectionSetup message may include RRC connection configuration information, etc. The RRC connection may also be referred to as a signaling radio bearer (SRB) and may be used during the transmission and reception of RRC messages, which are control messages between the UE and the eNB. The UE that has established the RRC connection sends an RRCConnectionSetupComplete message to the eNB (step 1e-15). The RRCConnectionSetupComplete message may include control messages such as a SERVICEREQUEST message for requesting the MME to configure a bearer for a specific service by the UE.

[0138] The eNB sends a SERVICE REQUEST message included in an RRCConnectionSetupComplete message to the MME (step 1e-20), and the MME may determine whether to provide the service requested by the UE. As a result of the determination, when the service requested by the UE is to be provided, the MME sends an INITIALCONTEXT SETUP REQUEST message to the eNB (step 1e-25). The INITIALCONTEXTSETUP REQUEST message may include QoS information to be applied when configuring the DRB, security information to be applied to the DRB (e.g., security key, security algorithm, etc.), etc.

[0139] The eNB exchanges SecurityModeCommand messages (step 1e-30) and SecurityModeComplete messages (step 1e-35) with the UE to configure the security mode. After configuring the security mode, the eNB sends an RRCConnectionReconfiguration message to the UE (step 1e-40). The RRCConnectionReconfiguration message may include configuration information about DRBs for processing user data, and the UE may configure the DRBs by using the configuration information and send an RRCConnectionReconfigurationComplete message to the eNB (step 1e-45).

[0140] After completing the DRB configuration with the UE, the eNB sends an INITIAL CONTEXT SETUP REQUEST COMPLETE message to the MME (step 1e-50), and upon reception, the MME exchanges an S1 BEARER SETUP message and an S1 BEARER SETUP RESPONSE message with the S-GW to configure the S1 bearer (steps 1e-55 and 1e-60). The S1 bearer is a connection configured between the S-GW and the eNB for data transmission, and corresponds to the DRB in a one-to-one manner.

[0141] After the above process is completed, in steps 1e-65 and 1e-70, the UE can send data to or receive data from the eNB through the S-GW. In this way, the general data transmission process can mainly include three steps: RRC connection establishment, security setup, and DRB configuration. The eNB can send an RRCConnectionReconfiguration message to the UE to renew, add, or change the configuration for a specific reason (step 1e-75).

[0142] Figure 1F A mobile communication system according to an embodiment is shown.

[0143] refer to Figure 1F In the LTE system, SRB or DRB can be configured by using the RRCConnectionReconfiguration message 1f-05. SRB-ToAddModList and DRB-ToAddModList include configuration information of SRB and DRB, respectively. For example, DRB-ToAddModList may generally include eps-beaerID, drb-ID, pdcp-Config, rlc-Config, logical channel ID (LCH-ID), and logicalChannelConfig. SRB-ToReleaseList or DRB-ToReleaseList can be used to release SRB or DRB. That is, DRB-related configuration information can be included. In the original LTE system, carrier aggregation and dual connectivity are not supported. However, by introducing the above-mentioned technology, a new information element (IE) is defined to configure SRB and DRB in SCell. In addition, dual connectivity needs to indicate the bearer type. Therefore, the current RRCConnectionReconfiguration message 1f-05 has a very complex structure.

[0144] In the next generation mobile communication system, the RRC signaling structure is designed to support carrier aggregation and dual connectivity, and supports the central unit-distributed unit (CU-DU) structure from the early version. Therefore, the next generation mobile communication system has an RRC signaling structure that is easier to understand and more efficient than previous systems. General SRB-ToAddModList and DRB-ToAddModList can be used, but unlike before, SRB-ToAddModList and DRB-ToAddModList can only include configuration information related to the SRB ID or DRB ID, PDCP layer and SDAP layer about the SRB or DRB. SRB-ToAddModList and DRB-ToAddModList can be included in RadioBearerConfig (radio bearer configuration) IE1f-10.

[0145] Instead, the configuration information below the RLC layer can be provided by rlc-BearerToAddModList which is a new IE. rlc-BearerToAddModList can be set in cell group units 1f-15 and 1f-20. rlc-BearerToAddModList can generally include LCH-ID, ServedRadioBearer, rlc-Config, and mac-LogicalChannelConfig. Accordingly, in order to use one SRB or DRB, SRB-ToAddModList or DRB-ToAddModList should be configured together with rlc-BearerToAddModList, and the SRB-ToAddModList or DRB-ToAddModList and rlc-BearerToAddModList applied to one SRB or DRB should be mapped (i.e., the srb-ID or drb-ID is mapped by being included in the ServedRadioBearer).

[0146] Figure 1G is a signal flow chart showing the UE operation process when UE 1g-01 in RRC connected mode receives an RRCReconfiguration message or an RRCResume message from gNB 1g-02 according to an embodiment.

[0147] refer to Figure 1G, when specific conditions are met, gNB 1g-02 sends an RRCReconfiguration (RRC reconfiguration) or RRCResume (RRC resume) message with full configuration set to UE 1g-01 (step 1g-05). Full configuration means deleting all previously applied configuration information and applying default configuration information or configuration information newly provided by gNB 1g-02. Full configuration can be used when the UE performs handover (when the UE receives an RRCReconfiguration or RRCResume message including reconfigurationWithSync (reconfiguration with synchronization) from the base station), when the target base station cannot understand the configuration information of the source base station, or when the base station switches basic configuration information rather than extended configuration information relative to the UE.

[0148] Specifically, when a handover is performed on a UE, the source base station may send configuration information provided to the UE to the target base station. The target base station may send only a portion of the received configuration information to be modified to the source base station. The source information may send configuration information applicable to the target base station to the UE. This process can reduce the amount of information to be sent between entities. However, when the source base station is a high version (e.g., Rel-15) and the target base station is a low version (e.g., Rel-8), even when the source base station sends configuration information to the target information, the target base station may not understand the target information provided to the UE. When the version increases, new IEs or fields may be added to compensate for existing functions or support new functions. Such new information cannot be understood by base stations of lower versions.

[0149] Therefore, in this case, the target base station may request the source base station to perform a complete configuration, and all configuration information may be sent to the source base station.

[0150] Here, considering the structure of the above-mentioned NR configuration information, when the base station triggers or does not trigger full configuration for a certain UE by using the RRCReconfiguration or RRCResume message, the RRC message may include one or more of the following information:

[0151] -fullConfig: Indicator indicating to perform a full configuration

[0152] -CellGroupConfig: IE including configuration information of cell group units (primary cell group (MCG) and / or secondary cell group (SCG))

[0153] -masterKeyUpdate: IE containing information for updating the security keys used by the UE in the MCG

[0154] -radioBearerConfig: IE containing configuration information about SRB and / or DRB

[0155] When the full configuration is triggered, in step 1g-10, UE 1g-01 may sequentially perform a zeroth operation, a first operation, and a second operation.

[0156] Operation Zero:

[0157] 1> Except for the supplementary configuration information associated with the MCG cell radio network temporary identifier (C-RNTI) and the master key, all radio configurations of the current dedicated configuration can be released / deleted. This is to delete all configuration information pre-applied by the UE and apply the default configuration information or the configuration information newly provided by the base station.

[0158] 1>When reconfigurationWithSync(switch) is included in spCellConfig which can be included in masterCellGroup,

[0159] 2> All current public radio configurations are released / deleted and default values ​​are available for T310 timers, T311 timers, N310 constants and N311 constants.

[0160] 1> Otherwise (when an RRCReconfiguration message is received that triggers a full configuration after performing the re-establishment procedure),

[0161] 2> The T310 timer value, T311 timer value, N310 constant value, and N311 constant value signaled from ue-TimersAndConstants included in the received SIB1 may be used.

[0162] 1> Apply the default physical channel configuration, the default semi-persistent scheduling / configuration grant configuration or the default MAC main configuration because the UE releases / deletes all configuration information.

[0163] 1> When srb-Identity is explicitly included in srb-ToAddModList which may be included in the radioBearerConfig of the reconfigured SRB,

[0164] 2>The specified configuration can be applied to the SRB regarding the corresponding srb-Identity.

[0165] 2> In addition, default PDCP configuration information, default RLC configuration information and default logical channel configuration information can be applied to the corresponding SRB.

[0166] First operation:

[0167] 1> About the PDU session belonging to the current UE configuration,

[0168] 2> The SDAP entity can be released because the PDU session and the SAP entity have a one-to-one mapping relationship. Therefore, the SDAP entity mapped to the PDU session belonging to the current UE configuration and the corresponding SDAP configuration information can be reconfigured by using the configuration information stored in SRB-ToAddModList and / or DRB-ToAddModList later.

[0169] 2> Each DRB and corresponding drb-identity associated with a PDU session can be released. Here, the UE releases the drb-identity together because the base station can reduce signaling overhead when considering the NR configuration information, and the UE can efficiently release the PDCP entity and RLC bearer. Because there may be one or more drb-identities associated with a PDU session, the UE can perform the DRB release operation through the following two methods:

[0170] - When the base station explicitly includes the drb-identity in the DRB-ToReleaseList, the UE may release the DRB, PDCP entity and RLC bearer corresponding to the indicated drb-identity.

[0171] -When the base station does not include drb-identity in DRB-ToReleaseList, the UE may implicitly release the drb-identity corresponding to each DRB released in association with the PDCU session to release the DRB, PDCP entity and RLC bearer corresponding to the released drb-identity. Therefore, when full configuration is set in the UE, the base station may signal the UE without including DRB-ToReleaseList in the RRCReconfiguration message or the RRCResume message.

[0172] 2> Release each RLC bearer associated with the released DRB or the released drb-identity.

[0173] Here, the operation of releasing the UE of the RLC bearer can be performed via the following two methods:

[0174] -When logicalchannelIdentity is explicitly included in rlc-BearerToReleaseList, the base station may release one or more RLC entities and corresponding logical channels corresponding to logicalchannelIdentity.

[0175] -When logicalchannelIdentity is not explicitly included in rlc-BearerToReleaseList, the base station may release one or more RLC entities corresponding to the logicalchannelIdentity associated with the DRB / drb-identity / PDCP entity released via the above procedure (result of full configuration), as well as the corresponding logical channels. Therefore, when full configuration is set in the UE, the base station may signal the UE without including the BearerToReleaseList in the RRCReconfiguration message or the RRCResume message.

[0176] Second operation:

[0177] 1> When drb-ToAddModList for a PDU session is not included in the PDU session belonging to the current UE configuration:

[0178] 2> When reconfigurationWithSync is included in the RRCReconfiguration or RRCResume message (for example, when operation 1g-05 is performed due to a handover),

[0179] 3> The upper layer may be notified that the user plane resources of the PDU session are released after a successful reconfiguration with a synchronization procedure or after a successful handover procedure. This is because, when the upper layer is notified that the user plane resources of the PDU session are released before a successful reconfiguration with a synchronization procedure or before a successful handover procedure, there is a risk that a NAS message may be sent to the AS before the procedure.

[0180] 2> Otherwise,

[0181] 3> The upper layer can be immediately notified that the user plane resources of the PDU session are released. The above process can be applied in the same way when full configuration is not triggered and an RRCReconfiguration message or an RRCResume message is received from the base station.

[0182] When UE 1g-01 receives the CellGroupConfig IE from gNB 1g-02 via the RRCReconfiguration message or the RRCResume message, the recommended UE operations in operation 1g-15 are as follows:

[0183] Third operation:

[0184] 1>When receiving the spCellConfig IE including reconfigurationWithSync in CellGroupConfig,

[0185] 2> Perform reconfiguration with synchronization procedure, all suspended radio bearers can be resumed, and SCG transmission can be resumed for all radio bearers (when suspended).

[0186] 1>When rlc-BearerToReleaseList IE is received in CellGroupConfig,

[0187] 2> The RLC bearer release process can be executed.

[0188] 1>When rlc-BearerToAddMdList IE is received via CellGroupConfig,

[0189] 2> RLC bearer addition and modification procedures can be performed.

[0190] 1> When mac-CellGroupConfig IE is received via CellGroupConfig,

[0191] 2>The MAC entity can be configured for the corresponding cell group.

[0192] 1>When sCellToReleaseList is received via CellGroupConfig,

[0193] 2> The Scell ​​release process can be executed.

[0194] 1>When spCellConfig is received via CellGroupConfig,

[0195] 2>SpCell can be configured.

[0196] 1>When sCellToAddModList is received via CellGroupConfig,

[0197] 2>Scell ​​addition and modification process can be performed.

[0198] When UE 1g-01 receives the radioBearerConfig IE from gNB 1g-02 via RRCReconfiguration message or RRCResume message, the recommended UE operations in operation 1g-20 are as follows:

[0199] Fourth operation:

[0200] 1>When srb3-ToRelease is included in RadioBearerConfig and configured as true,

[0201] 2>The SRB3 release process can be executed.

[0202] 1>When srb-ToAddModList IE is received via CellGroupConfig,

[0203] 2> The SRB addition or reconfiguration process can be performed.

[0204] 1>When drb-ToReleaseList is received via CellGroupConfig,

[0205] 2>The DRB release process can be executed.

[0206] 1>When drb-ToAddModList is received via CellGroupConfig,

[0207] 2>DRB addition or reconfiguration process can be performed.

[0208] 1> When there are no DRBs associated with all SDAP entities, the SDAP entities can be released.

[0209] 2>When the release process is triggered when receiving reconfigurationWithSync,

[0210] 3> For the PDU session associated with the released SDAP entity, the upper layers may be instructed that the user plane resources are released after a successful reconfiguration with synchronization procedure or a successful handover procedure.

[0211] 2> Otherwise,

[0212] 3> For the PDU session associated with the released SDAP entity, the upper layer may be immediately indicated that the user plane resources are released. For reference, when full configuration is not triggered and an RRCReconfiguration message or an RRCResume message is received from the base station, the above process may be applied in the same manner.

[0213] Figure 1H is a flowchart illustrating the operation of a UE according to an embodiment.

[0214] refer to Figure 1H In step 1h-01, the UE receives an RRC reconfiguration message or an RRC recovery message from the base station.

[0215] In step 1h-02, the UE determines the DRB and DRB identifier to be released from at least one DRB and at least one DRB identifier corresponding to the PDU session of the UE.

[0216] In step 1h-03, the UE releases the determined DRB and the determined DRB identifier.

[0217] Fig. 1I is a flowchart illustrating the operation of a base station according to an embodiment.

[0218] refer to Fig. 1I In step 1i-01, the base station determines whether the UE satisfies the full configuration conditions for reconfiguration of configuration information.

[0219] In step 1i-01, when it is determined that the condition for full configuration is met, the base station sends an RRC reconfiguration message or an RRC recovery message to the UE. The DRB and DRB identifier released from the UE can be determined based on the information included in the RRC reconfiguration message or the RRC recovery message.

[0220] Figure 2A is a signal flow diagram illustrating a process in which a UE switches an RRC connected mode to an RRC idle mode when an eNB releases a connection with the UE, and a process in which the UE establishes a connection with the eNB to switch the RRC idle mode to an RRC connected mode according to an embodiment.

[0221] refer to Figure 2A , when a UE that sends or receives data in RRC connected mode does not send or receive data due to a specific reason or at a specific time, the eNB sends an RRCConnectionReleas message to the UE to switch to RRC idle mode (step 2a-01). Thereafter, when data to be sent is generated, the UE that has not yet established a connection (hereinafter referred to as an idle mode UE) performs an RRC connection establishment process with the eNB. The UE establishes reverse transmission synchronization with the eNB through a random access process and sends an RRCConnectionRequest message to the eNB (step 2a-05). The RRCConnectionRequest message may include an identifier of the UE, an establishment cause, etc.

[0222] The eNB sends an RRCConnectionSetup message so that the UE establishes an RRC connection (step 2a-10). The RRCConnectionSetup message may include RRC connection configuration information, etc. The RRC connection may also be referred to as an SRB and may be used during transmission and reception of an RRC message as a control message between the UE and the eNB.

[0223] The UE that has established the RRC connection sends an RRCConnectionSetupComplete message to the eNB (step 2a-15). When there is flight path information available to the UE, the RRCConnectionSetupComplete message may include flightPathInfoAvailable. In addition, the RRCConnectionSetupComplete message may include a control message, such as a SERVICE REQUEST message for requesting the MME to configure a bearer for a specific service by the UE.

[0224] The eNB sends a SERVICE REQUEST message included in the RRCConnectionSetupComplete message to the MME (step 2a-20), and the MME determines whether to provide the service requested by the UE. As a result of the determination, when the service requested by the UE is to be provided, the MME sends an INITIAL CONTEXT SETUP REQUEST message to the eNB (step 2a-25). The INITIAL CONTEXT SETUP REQUEST message may include QoS information to be applied when configuring the DRB, security information to be applied to the DRB (e.g., security key, security algorithm, etc.), etc.

[0225] The eNB exchanges SecurityModeCommand messages (step 2a-30) and SecurityModeComplete messages (step 2a-35) with the UE to configure the security mode. After configuring the security mode, the eNB sends an RRCConnectionReconfiguration message to the UE (step 2a-40). The RRCConnectionReconfiguration message may include configuration information about DRBs for processing user data, and the UE may configure the DRBs by using the configuration information and send an RRCConnectionReconfigurationComplete message to the eNB (step 2a-45). When there is flight path information available to the UE, the RRCConnectionReconfigurationComplete message may include flightPathInfoAvailable.

[0226] After completing the DRB configuration with the UE, the eNB sends an INITIAL CONTEXT SETUP COMPLETE message to the MME (step 2a-50), and upon reception, the MME may exchange S1 BEARER SETUP messages and S1 BEARER SETUP RESPONSE messages with the S-GW to configure the S1 bearer (steps 2a-55 and 2a-60). The S1 bearer is a connection configured between the S-GW and the gNB for data transmission and corresponds to the DRB in a one-to-one manner.

[0227] After the above process is completed, in steps 2a-65 and 2a-70, the UE can send data to the eNB or receive data from the eNB through the S-GW. In this way, the data transmission process may include three steps: RRC connection establishment, security setting, and DRB configuration.

[0228] In addition, the eNB sends an RRCConnectionReconfiguration message to the UE to renew, add or change the configuration or perform a handover for a specific reason (step 2a-75). When the DRB is configured by applying the information included in the RRCConnectionReconfiguration message and there is flight path information available to the UE, the UE may send an RRCConnectionReconfigurationComplete message to the eNB by including flightPathInfoAvailable.

[0229] Figure 2B is a signal flow diagram showing a process in which a UE in RRC connected mode performs measurement when an eNB or gNB provides a measurement configuration applicable in RRC connected mode to the UE according to an embodiment.

[0230] refer to Figure 2B , the eNB or gNB sends an RRCConnectionReconfiguration message or an RRCConnectionResume message including measurement configuration information (measConfig) applicable in RRC connected mode to the UE (step 2b-01). The measConfig included in the message may include the following information:

[0231] 1. Measurement object: The object to be measured by the UE. For example, the following information can be a measurement object:

[0232] -When the UE accesses an LTE cell, the measurement object may represent a single Evolved Universal Terrestrial Radio Access (E-UTRA) carrier frequency for intra-frequency and inter-frequency measurements, and the base station may configure an offset list, a blacklist cell list, and a whitelist cell list for each cell in association with the corresponding carrier frequency. In the case of inter-RAT NR measurements, the measurement object may represent a single NR carrier frequency, and the base station may configure a list of blacklist cells in association with the corresponding carrier frequency.

[0233] -When the UE accesses an NR cell, the measurement object may indicate the frequency / time position to be measured and the subcarrier spacing of the reference signal used for intra-frequency and inter-frequency measurements, and the base station may configure an offset list, a blacklist cell list, and a whitelist cell list for each cell in association with the corresponding measurement object. In the case of inter-RAT E-UTRA measurements, the measurement object may indicate a single E-UTRA carrier frequency, and the base station may configure an offset list, a blacklist cell list, and a whitelist cell list for each cell in association with the corresponding carrier frequency. When the UE accesses an LTE cell or an NR cell, the UE may perform event evaluation or measurement reporting only on the whitelist cell list, but not on the blacklist cell list.

[0234] 2. Report configuration: a list of report configurations used to send a MeasurementReport message to the UE. For example, the following information can be individual report configurations:

[0235] -Reporting criteria: may include the conditions for the UE to send a MeasurementReport message, and the conditions may be periodic or described in a single event.

[0236] - Reporting format: The values ​​that the UE shall include in the MeasurementReport message and information related thereto (e.g. the number of cells / beams to be reported).

[0237] -RS type: RS used for beam or cell measurement results, such as synchronization signal block (SSB) or channel state information (CSI)-RS.

[0238] 3. Measurement ID: An ID used to identify a measurement object. Each ID can associate a report configuration with a measurement object.

[0239] 4. Quantity configuration: values ​​to be measured by the UE and layer 3 filter coefficients.

[0240] 5. Measurement gap: The period during which the UE measures neighboring cells.

[0241] In step 2b-01, upon receiving an RRCConnectionReconfiguration or RRCConnectionResume message including measConfig, the UE may perform the following series of operations:

[0242] - When the received measConfig includes measObjectToRemoveList, the measurement object removal process may be performed. measObjectToRemoveList may include a list of MeasObjectIDs to be removed.

[0243] -When measObjectToAddModList is included in the received measConfig, the measurement object addition / modification procedure may be performed. measObjectToAddModList may include a list of MeasObjectIDs to be newly added or changed and measObjects of one of the RATs (eg, measObjectEUTRA in the case of LTE).

[0244] -When the received measConfig includes reportConfigToRemoveList, the report configuration removal process may be performed. reportConfigToRemoveList may include a list of ReportConfigIDs to be removed.

[0245] -When the received measConfig includes reportConfigToAddModList, the report configuration adding / modifying process can be performed. reportConfigToAddModList can include reportConfigID or reportConfig list and reportConfig can be one of the following IEs:

[0246] *reportConfigEUTRA: IE including conditions for triggering E-UTRA measurement report events. For example, the base station can configure H1 events and / or H2 events to the UE by using this IE.

[0247] 1) H1 event: (in the air) when the UE's altitude is above an absolute threshold.

[0248] 2) H2 event: (in the air) when the UE's altitude is below an absolute threshold.

[0249] *reportConfigInterRAT: IE including conditions for triggering inter-RAT measurement reporting events.

[0250] -When the received measConfig includes quantityConfig, the quantity configuration procedure may be performed. quantityConfig includes the value to be measured by the UE for each RAT and the layer 3 filter coefficients. For example, the QuantityConfigEUTRA IE applicable to E-UTRA measurements includes RSRP and / or RSRQ and / or CSI RSRP and / or RS-SINR filter coefficients.

[0251] - When the received measConfig includes measIdToRemoveList, the measurement identity removal process may be performed. measIDRemoveList may include a list of MeasIDs (identifiers used to identify measurement configurations and connect measurement objects and report configurations).

[0252] - When the received measConfig includes measIdToAddModList, the measurement identity adding / modifying process may be performed. measIdToAddModList may include a list of MeasID, MeasObjectID, ReportConfigID (measurement report configuration identifier) ​​to be newly added or changed.

[0253] When the eNB or gNB configures the H1 event and / or H2 event to the UE in operation 2b-01, the UE can measure the height (operation 2b-05). Therefore, the UE can determine whether a measurement report is triggered for the H1 event and / or H2 event through the following series of processes.

[0254] - The UE determines whether security is successfully activated (operation 2b-10).

[0255] -The UE may then determine whether one of the following conditions is satisfied for each measID included in measIdList present in VarMeasConfig (measurement configuration information accumulated for measurements to be performed by the UE) as an internal variable:

[0256] *Condition 1: When during timeToTrigger, the entry condition is met with respect to the eventID corresponding to the reportConfig in VarMeasConfig, where the trigger type is set to event, the eventID is set to eventH1, H1Triggered as a UE variable is set to false, and VarMeasConfig is defined for eventH1 (operation 2b-15)

[0257] 1) The newly proposed / defined variable H1Triggered is used to enable the UE to perform the measurement reporting procedure discontinuously until H1Triggered is set to false later as the UE satisfies the entry condition during timeToTrigger by setting the corresponding value to true before / after the UE performs the measurement reporting procedure for the eNB or gNB. This is because the H1 event is triggered based on the height of the UE, so when the variable H1Triggered is not introduced, the UE may meet the entry condition every time during timeToTrigger. As an example, the variable is named H1Triggered and is set to false / true, so its name and setting method are not limited.

[0258] 2) The entry condition of eventH1 can be determined by the following equation (1):

[0259] [Equation 1]

[0260] Inequality H1-1 (entry condition)

[0261] Ms-Hys>Thresh+Offset

[0262] Definitions of parameters used in equation (1) may be based on the 3GPP standard document "36.331: RRC", and the parameters may be included in measConfig.

[0263] *Condition 2: When during timeToTrigger, the entry condition is met relative to the eventID corresponding to the reportConfig in VarMeasConfig, where the trigger type is set to event, the eventID is set to eventH2, H2Triggered as a UE variable is set to false, and VarMeasConfig is defined for eventH2 (operation 2b-15).

[0264] 1) The newly proposed / defined variable H2Triggered is used to indicate that the UE does not continuously perform the measurement reporting process by setting the corresponding value to true when the UE performs the measurement reporting process for the eNB or gNB as the UE meets the entry condition during timeToTrigger, until H2Triggered is set to false later. This is because the H2 event is triggered based on the height of the UE, so when the variable H2Triggered is not introduced, the UE may meet the entry condition every time during timeToTrigger. In the embodiments of the present disclosure, as an example, the variable is named H2Triggered and is set to false / true, so its name and setting method are not limited.

[0265] 2) The entry condition of eventH2 can be determined by the following equation (2):

[0266] [Equation 2]

[0267] Inequality H2-1 (entry condition)

[0268] Ms+Hys<Thresh+Offset

[0269] Definitions of parameters used in equation (2) may be based on the 3GPP standard document "36.331: RRC", and the parameters may be included in measConfig.

[0270] - The UE may include in VarMeasReportList a measurement report entry with respect to the measId that satisfies the condition (condition 1 or condition 2) described in step 2b-15 (step 2b-20).

[0271] - The UE may set numberOfReportsSent in VarMeasReportList to 0 for the measId described in step 2b-20 (step 2b-25).

[0272] -The UE may send a MeasurementReport message to the eNB or gNB by performing a measurement reporting procedure for eventH1 or eventH2 satisfied in step 2b-15. When possible, the MeasurementReport message may include the UE's height coordinates and / or information that the UE's height is set in heightUE (step 2b-30). In addition, before sending the MeasurementReport message, the UE may increase numberOfReportsSent by 1.

[0273] - When condition 1 is met, the UE may configure H1Triggered as true for eventH1, or when condition 2 is met, the UE may configure H2Triggered as true for eventH2 (step 2b-35). Step 2b-35 may be performed before step 2b-20, step 2b-25 or step 2b-30.

[0274] - In step 2b-40, the UE may determine whether one of the following conditions is met:

[0275] *Condition 3: When during timeToTrigger, the leaving condition is met with respect to the eventID corresponding to the reportConfig in VarMeasConfig, where the trigger type is set to event, the eventID is set to eventH1, H1Triggered as a UE variable is set to true, and VarMeasConfig is defined for eventH1 (step 2b-40)

[0276] 2) The exit condition of eventH1 can be determined by the following equation (3):

[0277] [Equation 3]

[0278] Inequality H1-2 (leave condition)

[0279] Ms+Hys<Thresh+Offset

[0280] Definitions of parameters used in equation (3) may be based on the 3GPP standard document "36.331: RRC", and the parameters may be included in measConfig.

[0281] *Condition 4: When during timeToTrigger, the leaving condition is met with respect to the eventID corresponding to the reportConfig in VarMeasConfig, where the trigger type is set to event, the eventID is set to eventH2, H2Triggered as a UE variable is set to true, and VarMeasConfig is defined for eventH2 (step 2b-40)

[0282] 2) The exit condition of eventH2 can be determined by the following equation (4):

[0283] [Equation 4]

[0284] Inequality H2-2 (leave condition)

[0285] Ms-Hys>Thresh+Offset

[0286] Definitions of parameters used in equation (4) may be based on 3GPP standard document "36.331: RRC", and the parameters may be included in measConfig.

[0287] -When one of the above conditions is met in step 2b-40, when reportOnLeave is set to true in the reporting configuration corresponding to the event (eventH1 or eventH2), the UE may perform a measurement reporting procedure and send a MeasurementReport message to the eNB or gNB. When possible, the MeasurementReport message may include information in which the height coordinates of the UE and / or the height of the UE are set in heightUE. Before sending the MeasurementReport message, the UE may increase numberOfReportsSent by 1. When reportOnLeave is set to false or does not exist with respect to eventH1 and / or eventH2, the UE may not perform the measurement reporting procedure, but immediately perform step 2b-50 (step 2b-45).

[0288] - The UE may set H1Triggered to false in case of eventH1, or set H2Triggered to false in case of eventH2 (step 2b-50). Step 2b-50 may be performed before step 2b-45.

[0289] Figure 2C is a signal flow diagram showing a process in which a UE in RRC connected mode performs measurement when an eNB or gNB provides a measurement configuration applicable in RRC connected mode to the UE according to an embodiment.

[0290] refer to Figure 2C , the eNB or gNB sends an RRCConnectionReconfiguration message or an RRCConnectionResume message including measurement configuration information (measConfig) applicable in RRC connected mode to the UE (step 2c-01). The measConfi included in the message may include the following information:

[0291] 1. Measurement object: The object to be measured by the UE. For example, the following information can be a measurement object:

[0292] -When the UE accesses an LTE cell, the measurement object may represent a single E-UTRA carrier frequency for intra-frequency and inter-frequency measurements, and the base station may configure an offset list, a blacklist cell list, and a whitelist cell list for each cell in association with the corresponding carrier frequency. In the case of inter-RAT NR measurements, the measurement object may represent a single NR carrier frequency, and the base station may configure a list of blacklist cells in association with the corresponding carrier frequency.

[0293] -When the UE accesses an NR cell, the measurement object may indicate the frequency / time position to be measured and the subcarrier spacing of the reference signal used for intra-frequency and inter-frequency measurements, and the base station may configure an offset list, a blacklist cell list, and a whitelist cell list for each cell in association with the corresponding measurement object. In the case of inter-RAT E-UTRA measurement, the measurement object may indicate a single E-UTRA carrier frequency, and the base station may configure an offset list, a blacklist cell list, and a whitelist cell list for each cell in association with the corresponding carrier frequency. When the UE accesses an LTE cell or an NR cell, the UE may perform event evaluation or measurement reporting only on the whitelist cell list, but not on the blacklist cell list.

[0294] 2. Report configuration: a list of report configurations used to send a MeasurementReport message to the UE. For example, the following information can be individual report configurations:

[0295] -Reporting criteria: The conditions under which the UE sends the MeasurementReport message, and the conditions can be periodic or described in a single event.

[0296] - Reporting format: The values ​​that the UE shall include in the MeasurementReport message and information related thereto (e.g. the number of cells / beams to be reported).

[0297] - RS type: RS used for beam or cell measurement results, such as SSB or CSI-RS.

[0298] 3. Measurement ID: An ID used to identify a measurement object. Each ID can associate a report configuration with a measurement object.

[0299] 4. Quantity configuration: values ​​to be measured by the UE and layer 3 filter coefficients.

[0300] 5. Measurement gap: The period during which the UE measures neighboring cells.

[0301] In step 2c-01, upon receiving an RRCConnectionReconfiguration or RRCConnectionResume message including measConfig, the UE may perform the following series of operations:

[0302] - When the received measConfig includes measObjectToRemoveList, the measurement object removal process may be performed. measObjectToRemoveList may include a list of MeasObjectIDs to be deleted.

[0303] -When measObjectToAddModList is included in the received measConfig, the measurement object addition / modification procedure may be performed. measObjectToAddModList may include a list of MeasObjectIDs to be newly added or changed and measObjects of one of the RATs (eg, measObjectEUTRA in the case of LTE).

[0304] -When the received measConfig includes reportConfigToRemoveList, the report configuration removal process may be performed. reportConfigToRemoveList may include a list of ReportConfigIDs to be removed.

[0305] -When the received measConfig includes reportConfigToAddModList, the report configuration adding / modifying process can be performed. reportConfigToAddModList can include reportConfigID or reportConfig list and reportConfig can be one of the following IEs:

[0306] *reportConfigEUTRA: IE including conditions for triggering E-UTRA measurement reporting events. For example, the IE may enable the base station to configure H1 events and / or H2 events to the UE.

[0307] 1) H1 event: (in the air) when the UE's altitude is above an absolute threshold.

[0308] 2) H2 event: (in the air) when the UE's altitude is below an absolute threshold.

[0309] *reportConfigInterRAT: IE including conditions for triggering inter-RAT measurement reporting events.

[0310] -When the received measConfig includes quantityConfig, the quantity configuration procedure may be performed. quantityConfig includes the value to be measured by the UE for each RAT and the layer 3 filter coefficients. For example, the QuantityConfigEUTRA IE applicable to E-UTRA measurements may include RSRP and / or RSRQ and / or CSI RSRP and / or RS-SINR filter coefficients.

[0311] - When the received measConfig includes measIdToRemoveList, the measurement identity removal process may be performed. measIDRemoveList may include a list of MeasIDs (identifiers used to identify measurement configurations and connect measurement objects and report configurations).

[0312] - When the received measConfig includes measIdToAddModList, the measurement identity adding / modifying process may be performed. measIdToAddModList may include a list of MeasID, MeasObjectID, ReportConfigID (measurement report configuration identifier) ​​to be newly added or changed.

[0313] When the eNB or gNB configures the H1 event and / or H2 event to the UE in step 2c-01, the UE may measure the height (step 2c-05). The UE may determine whether a measurement report is triggered for the H1 event and / or H2 event through the following series of processes:

[0314] - The UE determines whether security is successfully activated (step 2c-10).

[0315] - The UE may determine whether one of the following conditions is satisfied for each measID included in the measIdList present in VarMeasConfig (measurement configuration information accumulated for measurements to be performed by the UE) as an internal variable.

[0316] *Condition 1: During timeToTrigger, when the entry condition is met with respect to the eventId corresponding to the reportConfig in VarMeasConfig, where the trigger type is set to event, the eventId is set to eventH1, the entry is not included in the measID for VarMeasReportList, and VarMeasConfig is defined for eventH1 (step 2c-15)

[0317] 1) When an entry is included in measID for VarMeasReportList, condition 1 is not satisfied. This is to enable the UE to perform the measurement reporting procedure discontinuously.

[0318] 2) The entry condition of eventH1 can be determined by the following equation (5):

[0319] [Equation 5]

[0320] Inequality H1-1 (entry condition)

[0321] Ms-Hys>Thresh+Offset

[0322] Definitions of parameters used in equation (5) may be based on 3GPP standard document "36.331: RRC", and the parameters may be included in measConfig.

[0323] *Condition 2:-When during timeToTrigger, the entry condition is met for the eventId corresponding to the reportConfig in VarMeasConfig, where the trigger type is set to event, the eventId is set to eventH2, the entry is not included in the measID for VarMeasReportList, and VarMeasConfig is defined for eventH2 (operation 2c-15)

[0324] 1) When an entry is included in measID for VarMeasReportList, condition 2 is not satisfied. This is to enable the UE to perform the measurement reporting procedure discontinuously.

[0325] 2) The entry condition of eventH2 can be determined by the following equation (6):

[0326] [Equation 6]

[0327] Inequality H2-1 (entry condition)

[0328] Ms+Hys<Thresh+Offset

[0329] Definitions of parameters used in equation (6) may be based on the 3GPP standard document "36.331: RRC", and the parameters may be included in measConfig.

[0330] - The UE may include in VarMeasReportList a measurement report entry with respect to the measId that satisfies the condition (condition 1 or condition 2) described in step 2c-15 (step 2c-20).

[0331] - The UE may set numberOfReportsSent in VarMeasReportList to 0 for the measId described in step 2c-20 (step 2c-25).

[0332] -The UE may send a MeasurementReport message to the eNB or gNB by performing a measurement reporting procedure for eventH1 or eventH2 satisfied in step 2c-15. When possible, the MeasurementReport message may include the UE's height coordinates and / or information that the UE's height is set in heightUE (step 2c-30). Before sending the MeasurementReport message, the UE may increase numberOfReportsSent by 1.

[0333] -In operation 2c-35, the UE may determine whether one of the following conditions is met.

[0334] *Condition 3:- When during timeToTrigger, the leaving condition is met for the eventId corresponding to the reportConfig in VarMeasConfig, where the trigger type is set to event, the eventId is set to eventH1, the entry is included in the measID for VarMeasReportList, and VarMeasConfig is defined for eventH1 (step 2c-35)

[0335] 2) The exit condition of eventH1 can be determined by the following equation (7):

[0336] [Equation 7]

[0337] Inequality H1-2 (leave condition)

[0338] Ms+Hys<Thresh+Offset

[0339] Definitions of parameters used in Equation 3 may be based on 3GPP standard document "36.331: RRC", and the parameters may be included in measConfig settings.

[0340] *Condition 4:- When during timeToTrigger, the leaving condition is met for the eventId corresponding to the reportConfig in VarMeasConfig, where the trigger type is set to event, the eventId is set to eventH2, the entry is included in the measID for VarMeasReportList, and the VarMeasConfig is defined for eventH2 (step 2c-35)

[0341] 2) The exit condition of eventH2 can be determined by the following equation (8):

[0342] [Equation 8]

[0343] Inequality H2-2 (leave condition)

[0344] Ms-Hys>Thresh+Offset

[0345] Definitions of parameters used in equation (8) may be based on 3GPP standard document "36.331: RRC", and the parameters may be included in measConfig.

[0346] - When one of the conditions described in step 2c-40 is met, the UE may remove the measurement report entry included in the VarMeasReportList for the measID.

[0347] -When reportOnLeave is set to true in the reporting configuration corresponding to the event (eventH1 or eventH2) in step 2c-45, a measurement reporting procedure may be performed to send a MeasurementReport message to the eNB or gNB. When possible, the MeasurementReport message may include information in which the height coordinates of the UE and / or the height of the UE are set in heightUE. Before sending the MeasurementReport message, the UE may increase numberOfReportsSent by 1.

[0348] Figure 2D is a flowchart illustrating a process in which a UE switches an RRC connected mode to an RRC idle mode when a base station releases a connection with the UE and the UE selects a Global System for Mobile Communications (GSM) or UTRAN cell in the RRC idle mode according to an embodiment.

[0349] refer to Figure 2D In step 2d-05, after establishing an RRC connection with the NR base station, the UE is in RRC connected mode.

[0350] In step 2d-10, the UE receives an RRC release message (RRCRelease) from the NR base station. RRCRelease may not include suspended configuration information (suspendConfig). RRCRelease may include cell reselection priority configuration information (cellReselectionPriorities). cellReselectionPriorities may include at least one of the following:

[0351] -freqPriorityListEUTRA: One or more LTE frequencies and corresponding priority values

[0352] -freqPriorityListNR: One or more NR frequencies and corresponding priority values

[0353] -t320: t320 timer value

[0354]

[0355] In step 2d-15, the UE transitions to RRC idle mode, and then the UE applies the information configured in step 2d-10. For example, the UE may drive the t320 timer and perform a cell reselection or cell selection procedure based on the configured cellReselectionPriorities.

[0356] In step 2d-20, during RRC idle mode, the UE performs inter-RAT cell selection for a GSM or UTRAN cell from the NR.

[0357] In step 2d-25, when a GSM or UTRAN cell is selected, the UE may not inherit the cellReselectionPriorities and remaining validity time specifically configured from the NR base station in step 2d-10. Alternatively, the UE may inherit the cellReselectionPriorities and validity time for LTE without inheriting the cellReselectionPriorities for NR.

[0358] Figure 3A Vehicle-to-everything (V2X) communication in a mobile communication system according to an embodiment is shown.

[0359] Here, V2X generally refers to communication technology with vehicles via all interfaces, and may include vehicle-to-vehicle (V2V), vehicle-to-infrastructure (V2I), vehicle-to-pedestrian (V2P), and vehicle-to-network (V2N) based on their types and components performing communication.

[0360] refer to Figure 3A , the eNB / gNB 3a-01 may include at least one of a vehicle terminal 3a-05 or 3a-10 or a pedestrian mobile terminal 3a-15 located within a V2X-supporting cell 3a-02. V2X may be supported via a UMTS air (Uu) interface. For example, the vehicle terminals 3a-05 and 3a-10 may perform cellular communication with the eNB / gNB 3a-01 by using the vehicle terminal-base station UL / DL 3a-30 and 3a-35, and the pedestrian mobile terminal 3a-15 may perform cellular communication with the eNB / gNB 3a-01 by using the pedestrian terminal-base station UL / DL 3a-50.

[0361] V2X can be supported via the PC5 interface. V2X via the PC5 interface can perform V2X side link (SL) communication by using the terminal-terminal SL 3a-20 or 3a-25. For example, a vehicle terminal 3a-05 within the E-UTRA / NR coverage can send or receive V2X data packets via SL 3a-20, 3a-50, 3a-25 or 3a-60 as a transmission channel with another vehicle terminal 3a-10 or 3a-45 or a pedestrian mobile terminal 3a-15 or 3a-55 based on a resource allocation mode (scheduled resource allocation or UE autonomous resource selection) or pre-configured resources.

[0362] Scheduling resource allocation (mode 1 or mode 3) may include a method in which a base station allocates resources used in SL transmission to an RRC-connected terminal in a dedicated scheduling manner. Scheduling resource allocation may be effective in interference management and resource pool management (dynamic allocation, semi-persistent transmission, etc.) because the base station is able to manage the resources of the SL. When there is data to be sent to other UEs, a UE in RRC connected mode may send information indicating the presence of data to be sent to other UEs to the base station by using an RRC message or a MAC control element (CE). For example, the RRC message may include a SidelinkUEInformation or UEAssistanceInformation message, and the MAC CE may include a new format of a buffer status report MAC CE (including at least an indicator notifying a buffer status report for V2X communication and information about the size of data buffered for SL communication).

[0363] UE autonomous resource selection (mode 2 or mode 4) may be a method in which the base station provides the UE with a SL transmission and reception resource pool for V2X via system information or an RRC message (e.g., an RRCReconfiguration message or a PC5-RRC message), and the UE selects the resource pool according to a determined rule. UE autonomous resource selection may belong to one or more of the following resource allocation modes:

[0364] -UE autonomously selects sidelink resources for transmission

[0365] -UE helps other UEs to select sidelink resources

[0366] -UE is configured with NR configuration grant for sidelink transmission

[0367] -UE schedules other UEs’ sidelink transmissions

[0368] The resource selection methods of the UE may include area mapping, sensing-based resource selection, and random selection.

[0369] Even within the coverage of E-UTRA / NR, the UE may not be able to perform scheduling resource allocation or UE autonomous resource selection, in which case the UE may perform V2X SL communication via a preconfigured SL transmit and receive resource pool (preconfiguration resources). For example, the Preconfiguration resources may refer to v2x-CommRxPoolList in SL-V2X-Preconfiguration and / or v2x-CommTxPoolList or p2x-CommTxPoolList in SL-V2X-Preconfiguration.

[0370] A vehicle terminal 3a-45 that is not within the E-UTRA / NR coverage can perform V2X SL communication with another vehicle terminal 3a-65 or a pedestrian mobile terminal 3a-55 via SL 3a-70 or 3a-75 based on SL Preconfiguration resources.

[0371] Because LTE is mainly designed for basic safety services, LTE SL communication is designed so that one UE performs a process of establishing a separate session with another specific UE, or is supported only by a broadcast transmission type without performing a SL connection establishment process. However, V2X SL communication can be designed to provide basic safety services and various improved services (e.g., autonomous driving services, platooning services, remote driving services, and in-vehicle infotainment) in the next generation mobile communication (NR). Therefore, NR V2X SL communication can be designed to support a broadcast transmission type, as well as a unicast and / or multicast transmission type.

[0372] Figure 3B is a signal flow diagram illustrating a unicast link establishment process for NR V2X SL support according to an embodiment.

[0373] refer to Figure 3B , the vehicle terminal 3b-01 performs a discovery process with another vehicle terminal or pedestrian mobile terminal 3b-02 in step 3b-05 to establish a unicast link. Therefore, the destination layer 2 ID (or the destination ID of the target UE) for NR V2X SL of the other vehicle terminal or pedestrian mobile terminal 3b-02 can be obtained.

[0374] In step 3b-10, the vehicle terminal 3b-01 performs an upper layer connection establishment process by sending a DIRECT_COMMUNICATION_REQUEST message to another vehicle terminal or a pedestrian mobile terminal 3b-02. The DIRECT_COMMUNICATION_REQUEST message may be a PC5 signaling message generated in the PC5 signaling protocol.

[0375] In step 3b-15, the vehicle terminal 3b-01 performs the AS layer connection establishment process by sending a PC5-RRC message to another vehicle terminal or a pedestrian mobile terminal 3b-02. Here, the time point for sending the PC5-RRC message in operation 3b-15 is proposed. The PC5-RRC message can be:

[0376] -Sent simultaneously with the DIRECT_COMMUNICATION_REQUEST message,

[0377] -Sent by multiplexing with the DIRECT_COMMUNICATION_REQUEST message,

[0378] - Sent after sending a DIRECT_COMMUNICATION_REQUEST message,

[0379] - Sent after receiving a DIRECT_SECURITY_MODE_COMMAND message,

[0380] -Sent simultaneously with the DIRECT_SECURITY_MODE_COMPLETE message,

[0381] - sent by multiplexing with the DIRECT_SECURITY_MODE_COMPLETE message,

[0382] - after sending a DIRECT_SECURITY_MODE_COMPLETE message, or

[0383] - Sent after receiving a DIRECT_COMMUNICATION_ACCEPT message.

[0384] The message may include some or all of the following information as the RC5 RRC message of step 3b-15 generated via RRC.

[0385] - Indicator or IE indicating whether to use reconfiguration of the sending resource pool and / or receiving resource pool:

[0386] ■Through an indicator or IE, two UEs determine whether to use a preconfigured transmit resource pool and / or receive resource pool, or a separate transmit / receive pool, when transmitting and receiving V2X data packets via NR V2X SL unicast, based on the resource allocation mode (scheduled resource allocation (mode 1 or mode 3) and / or UE autonomous resource selection (mode 2 or mode 4)). For example, the indicator or IE can be expressed in the form of true / false or Boolean, or in the form of an integer or enumeration.

[0387] ■The preconfigured transmission resource pool may represent the v2x-CommTxPoolList or p2x-CommTxPoolList included in the SL-V2X-Preconfiguration IE, and the preconfiguration reception resource pool may represent the v2x-CommRxPoolList included in the SL-V2X-Preconfiguration IE.

[0388] - Indicator or IE indicating whether the link is established for one-to-one (unicast) and / or one-to-relay (unicast) and / or one-to-many (groupcast and / or multicast and / or broadcast) purposes:

[0389] ■ Through an indicator or IE, it is determined that the NR V2X SL communication will be performed between two UEs via one-to-one unicast. For example, the indicator or IE can be expressed in the form of an integer or an enumeration.

[0390] -IEs related to 5G QoS Indicator (5QI) or V2X QoS Indicator (VQI) indicating QoS related information:

[0391] ■Through this IE, QoS information for the desired V2X service during NR V2X SL communication can be indicated via unicast between two UEs. For example, this IE can include a list of 5QIs or VQIs.

[0392] - IEs including prose per-packet priority (PPPP) and / or prose per-packet reliability (PPPR) indicating QoS related information or traffic pattern information;

[0393] ■Through this IE, QoS information for the desired V2X service during NR V2X SL communication can be indicated via unicast between two UEs. For example, this IE can include PPPPInfoSL and / or reliabilityInfoListSL and / or SL-V2X-PacketDuplicationConfig and / or trafficPatternInfoListSL.

[0394] -Pre-configure some resource pool information IE in the sending resource pool and / or receiving resource pool:

[0395] ■Through this IE, two UEs can perform NR V2X SL communication via unicast by using part of the resource pools in the preconfigured transmission resource pool and / or reception resource pool. For example, this IE can be the transmission resource pool v2x-CommTxPoolList or p2x-CommTxPoolList and / or v2x-CommRxPoolList or reception resource pool v2x-CommTxPoolList included in SL-V2X-Preconfiguration.

[0396] - IE including separate SL transmission / reception resource pool information by resource allocation mode (scheduled resource allocation (mode 1 or mode 3) or UE autonomous resource selection (mode 2 or mode 4)):

[0397] ■When this IE is included, the two UEs may determine that the NR V2X SL communication will be performed via unicast by using the separate transmit / receive resource pool included in this IE. For example, the separate SL transmit / receive resource pool may represent part or all of the transmit / receive resource pools included in the system information or RRCReconfiguration message.

[0398] ■When this IE is empty (not present), the two UEs may implicitly determine that the NR V2X SL communication will be performed via unicast using preconfigured transmit resources and / or receive resources.

[0399] -V2X Tx Profile List IE supported by vehicle terminal 3f-01:

[0400] ■ Through this IE, the UE can indicate the supported transport formats (e.g., Rel-15, Rel-16 or Rel-17).

[0401] ■Through this IE, the QAM, MAC table, etc. supported by the UE can be indicated.

[0402] - New timer:

[0403] ■This timer can be driven when sending a PC5-RRC message.

[0404] ■The timer can be stopped when a PC5-RRC message is received from another vehicle terminal or pedestrian mobile terminal 3b-02.

[0405] ■When no PC5-RRC message is received from another vehicle terminal or pedestrian mobile terminal 3b-02 until the timer expires, the AS layer can notify the upper layer that the AS layer connection establishment process failed. Here, the AS layer can also notify the AS layer of the reason for the failure of the connection establishment process.

[0406] ■When the upper layer is notified from the AS layer that the AS layer connection establishment process has failed, the upper layer can release the unicast link that has been established or is about to be established without a separate signaling process. Alternatively, in order to release the unicast link that has been established or is about to be established, the upper layer can send a PC5 signaling message generated in the PC5-signaling protocol to another vehicle terminal or pedestrian mobile terminal 3b-02. For example, the PC5 signaling message can be a disconnect request message.

[0407] ■When no PC5-RRC message is received from another vehicle terminal or pedestrian mobile terminal 3b-02 until the timer expires, the upper layer may send a PC5-RRC message (e.g., PC5-RRC Release) to the other vehicle terminal or pedestrian mobile terminal 3b-02 to release the established or to-be-established unicast link.

[0408] ■When the PC5-RRC message is not received from another vehicle terminal or pedestrian mobile terminal 3b-02 until the timer expires, the vehicle terminal 3b-01 can resend the PC5-RRC message to another vehicle terminal or pedestrian mobile terminal 3b-02.

[0409] When receiving the DIRECT_COMMUNICATION_REQUEST message in step 3b-10, another vehicle terminal or pedestrian mobile terminal 3b-02 may perform the direct security mode control process by sending a DIRECT_SECURITY_MODE_COMMAND message to the vehicle terminal 3b-01 in step 3b-20. The DIRECT_SECURITY_MODE_COMMAND message may be a PC5 signaling message generated in the PC5 signaling protocol.

[0410] When another vehicle terminal or pedestrian mobile terminal 3b-02 receives a PC5-RRC message from the vehicle terminal 3b-01, in response, the other vehicle terminal or pedestrian mobile terminal 3b-02 may send a PC5-RRC message to the vehicle terminal 3b-01 (step 3b-25). In the present disclosure, the time point for sending the PC5-RRC message in operation 3b-25 is proposed. The PC5-RRC message may be:

[0411] - immediately after receiving the PC5-RRC message in operation 3b-15,

[0412] - before sending a DIRECT_SECURITY_MODE_COMMAND message,

[0413] -Sent simultaneously with the DIRECT_SECURITY_MODE_COMMAND message,

[0414] - sent by multiplexing with the DIRECT_SECURITY_MODE_COMMAND message,

[0415] - Sent after sending a DIRECT_SECURITY_MODE_COMMAND message,

[0416] - Sent after receiving a DIRECT_SECURITY_MODE_COMPLETE message,

[0417] -Sent simultaneously with the DIRECT_COMMUNICATION_ACCEPT message,

[0418] - sent by multiplexing with a DIRECT_COMMUNICATION_ACCEPT message, or

[0419] - Sent after a DIRECT_COMMUNICATION_ACCEPT message is sent.

[0420] The message may include some or all of the following information as the RC5 RRC message of step 3b-25 generated via RRC:

[0421] - An indicator or IE that explicitly indicates whether to use reconfiguration of the sending resource pool and / or receiving resource pool:

[0422] ■Through an indicator or IE, two UEs determine whether to use a preconfigured transmit resource pool and / or receive resource pool, or a separate transmit / receive pool, when transmitting and receiving V2X data packets via NR V2X SL unicast, based on the resource allocation mode (scheduled resource allocation (mode 1 or mode 3) and / or UE autonomous resource selection (mode 2 or mode 4)). For example, the indicator or IE can be expressed in the form of true / false or Boolean, or in the form of an integer or enumeration.

[0423] ■For example, the pre-configured transmission resource pool may represent v2x-CommTxPoolList or p2x-CommTxPoolList included in the SL-V2X-Preconfiguration IE, and the pre-configured reception resource pool may represent v2x-CommRxPoolList included in the SL-V2X-Preconfiguration IE.

[0424] - Indicator or IE indicating a response to establishing a link for one-to-one (unicast) and / or one-to-relay (unicast) and / or one-to-many (groupcast and / or multicast and / or broadcast) purposes:

[0425] ■Through this indicator or IE, a response or rejection regarding performing NR V2XSL communication between two UEs through one-to-one unicast can be indicated. For example, the indicator or IE can be represented in the form of an integer or enumeration.

[0426] -IEs related to 5G QoS Indicator (5QI) or V2X QoS Indicator (VQI) indicating QoS related information:

[0427] ■Through this IE, QoS information for the desired V2X service during NR V2X SL communication can be indicated via unicast between two UEs. For example, this IE can include a list of 5QIs or VQIs.

[0428] - IEs including PPPP and / or PPPP indicating QoS related information or traffic pattern information:

[0429] ■Through this IE, QoS information for the desired V2X service during NR V2X SL communication can be indicated via unicast between two UEs. For example, this IE can include PPPPInfoSL and / or reliabilityInfoListSL and / or SL-V2X-PacketDuplicationConfig and / or trafficPatternInfoListSL.

[0430] -Pre-configure some resource pool information IE in the sending resource pool and / or receiving resource pool:

[0431] ■Through this IE, two UEs can perform NR V2X SL communication via unicast by using part of the resource pools in the preconfigured transmission resource pool and / or reception resource pool. For example, this IE can be the transmission resource pool v2x-CommTxPoolList or p2x-CommTxPoolList and / or v2x-CommRxPoolList or reception resource pool v2x-CommTxPoolList included in SL-V2X-Preconfiguration.

[0432] - IE including separate SL transmission / reception resource pool information by resource allocation mode (scheduled resource allocation (mode 1 or mode 3) or UE autonomous resource selection (mode 2 or mode 4));

[0433] ■When this IE is included, two UEs can determine that NR V2X SL communication will be performed via unicast by using a separate transmit / receive resource pool included in this IE.

[0434] ■A separate SL transmit / receive resource pool may represent part or all of the transmit / receive resource pools included in the system information or the RRCReconfiguration message. For example, a separate SL transmit / receive resource pool may be part or all of the transmit / receive resource pool information (v2x-CommTxPool and / or v2x-CommTxPoolNormalCommon and / or p2x-CommTxPoolNormalPool and / or v2x-CommTxPoolExceptional and / or v2x-InterFreqInfoList IE) included in the SL-V2X-ConfigCommon IE in the system information, or part or all of the transmit / receive resource pool information in the sl-V2X-ConfigDedicated IE in the RRCReconfiguration message.

[0435] ■When this IE is empty (not present), the two UEs may implicitly determine that the NR V2X SL communication will be performed via unicast using preconfigured transmit resources and / or receive resources.

[0436] Another vehicle terminal or pedestrian mobile terminal 3b-02 may determine that the PC5-RRC message is not successfully received from the vehicle terminal 3b-01. Another vehicle terminal or pedestrian mobile terminal 3b-02 may determine that the PC5-RRC message is not successfully received in at least one of the following situations.

[0437] ■When decoding of the PC5-RRC message received in operation 3f-15 fails (e.g., integrity check fails) based on the security algorithm (integrity protection algorithm and / or encryption algorithm) to be used in the AS layer via the direct security mode process and the security key derived therefrom.

[0438] ■When the (partial) configuration included in the PC5-RRC message received in operation 3b-15 cannot be complied with.

[0439] When another vehicle terminal or pedestrian mobile terminal 3b-02 determines that the PC5-RRC message has not been successfully received from the vehicle terminal 3b-01, in response, the other vehicle terminal or pedestrian mobile terminal 3b-02 sends a PC5-RRC message to the vehicle terminal 3b-01 (step 3b-25). For example, the PC5-RRC message may be a message for releasing a unicast link that has been established or is to be established (e.g., a PC5-RRC release message). The message may include a reason for releasing the link (ReleaseCause). Alternatively, the PC5-RRC message may be a message indicating that the PC5-RRC message has not been successfully received from the vehicle terminal 3b-01 (e.g., a PC5-RRC reject message). The PC5-RRC message may include the reason (RejectCause) for not successfully receiving the PC5-RRC message. When the (partial) configuration information included in the PC5-RRC message cannot be applied or complies with, the PC5-RC message may include corresponding information.

[0440] When the vehicle terminal 3b-01 receives a PC5-RRC message indicating that the PC5-RRC message sent from another vehicle terminal or the pedestrian mobile terminal 3b-02 in step 3b-15 is not successfully received, the vehicle terminal 3b-01 may perform at least one of the following in step 3b-40:

[0441] ■The PC5-RRC message may be retransmitted to another vehicle terminal or pedestrian mobile terminal 3b-02 to perform the AS layer connection establishment process. When information that cannot be applied or conforms to the configuration information is included in the PC5-RRC message in step 3b-25, the vehicle terminal 3b-01 may send the PC5-RRC message to another vehicle terminal or pedestrian mobile terminal 3b-02 by changing or not including the corresponding configuration information. In other words, in step 3b-40, the vehicle terminal 3b-01 may send the PC5-RRC message to another vehicle terminal or pedestrian mobile terminal 3b-02 by modifying the configuration information included in the PC5-RRC message sent in step 3b-15.

[0442] ■The AS layer of the vehicle terminal 3b-01 can instruct the upper layer to release the unicast link. The vehicle terminal 3b-01 can send a PC5-Signaling message to another vehicle terminal or a pedestrian mobile terminal 3b-02 to release the unicast link that has been established or is about to be established. For example, the PC5-Signaling message can be a disconnection request message.

[0443] ■The AS layer of the vehicle terminal 3b-01 can instruct the upper layer to release the unicast link, and release the unicast link that has been established or is to be established without the need for a separate signaling process.

[0444] When another vehicle terminal or pedestrian mobile terminal 3b-02 successfully receives the PC5-RRC message in step 3b-40, in response, the other vehicle terminal or pedestrian mobile terminal 3b-02 may send a PC5-RRC message to the vehicle terminal 3b-01 in step 3b-40.

[0445] When another vehicle terminal or pedestrian mobile terminal 3b-02 receives a disconnect request message as a PC5-Signaling message in step 3b-40, in step 3b-45, the other vehicle terminal or pedestrian mobile terminal 3b-02 may send a disconnect response message to the vehicle terminal 3b-01 in response.

[0446] Figure 3C is a signal flow diagram illustrating a process of performing NR V2X SL unicast communication via a pre-configured transmission resource pool and / or reception resource pool in an inter-UE scheduling resource allocation mode according to an embodiment.

[0447] refer to Figure 3C In step 3c-05, the vehicle terminal 3c-01 performs a discovery process with another vehicle terminal or a pedestrian mobile terminal 3c-02, and in step 3c-10, performs a unicast link establishment process for NR V2X SL communication. The unicast link establishment process can be performed via the above-mentioned embodiments of the present disclosure.

[0448] When the V2X packet is generated in step 3c-15, the vehicle terminal 3c-01 can perform NR V2X SL unicast with another vehicle terminal or pedestrian mobile terminal 3c-02.

[0449] When operating in a scheduling resource allocation mode (mode 1 or mode 3), in step 3c-20, the vehicle terminal 3c-01 requests transmission resources for performing NR V2X SL unicast from the base station 3c-03. That is, the vehicle terminal 3c-01 can request transmission resources by sending an RRC message (e.g., SidelinkUEInformation or UEAssistInfomration) or MAC CE to the base station 3c-03. In response, the base station 3c-03 can allocate V2X transmission resources to the vehicle terminal 3c-01 via a dedicated RRC message (step 3c-25). For example, the dedicated RRC message can be an RRC connection reconfiguration message (RRCReconfiguration message). The vehicle terminal 3c-01 can select resources from the resources indicated by the self-base station 3c-03 or the exception resources (exception pool), and send V2X data to another vehicle terminal or pedestrian mobile terminal 3c-02 (step 3c-30). Here, the exception pool can represent a resource pool that is pre-configured to be selected in specific circumstances rather than in general circumstances. Steps 3c-20 and 3c-25 may be performed before step 3c-10. In this case, the vehicle terminal 3c-01 may perform NR V2X SL unicast communication by sending the resources indicated from the base station 3c-03 via a dedicated RRC message in step 3c-10 to another vehicle terminal or pedestrian mobile terminal 3c-02 via a PC5-RRC message.

[0450] In order to perform NR V2X SL unicast communication based on the scheduling resource allocation mode and through the preconfigured transmission resource pool and / or reception resource pool, the vehicle terminal 3c-01 sends a PC5-RRC message or a PC5 MAC CE to another vehicle terminal or a pedestrian mobile terminal 3c-02 (step 3c-35). NR V2X SL unicast communication is performed through the preconfigured transmission resource pool and / or reception resource pool in the scheduling resource allocation mode due to one or more of the following reasons:

[0451] -When a UE in RRC connected mode transitions to RRC inactive mode or RRC idle mode. For example:

[0452] ■When receiving the RRCRelease message from the base station,

[0453] ■When the RRC reconfiguration process fails (Reconfiguration Failure), or

[0454] ■When an RRCReject message is received from the base station.

[0455] -Beyond the coverage of E-UTRA / NR

[0456] The PC5-RRC message or PC5 MAC CE message may include some or all of the following information:

[0457] - An indicator or IE that explicitly indicates whether to use reconfiguration of the sending resource pool and / or receiving resource pool.

[0458] ■Through the indicator or IE, the two UEs may determine that the V2X data packets are to be transmitted and received via NR V2X SL unicast by using the preconfigured transmit resource pool and / or receive resource pool. For example, the indicator or IE may be expressed in the form of true / false or Boolean, or in the form of an integer or enumeration.

[0459] ■For example, the pre-configured transmission resource pool may represent v2x-CommTxPoolList or p2x-CommTxPoolList included in the SL-V2X-Preconfiguration IE, and the pre-configured reception resource pool may represent v2x-CommRxPoolList included in the SL-V2X-Preconfiguration IE.

[0460] -Preconfiguration sends the resource pool and / or receives part of the resource pool information IE in the resource pool.

[0461] ■Through this IE, two UEs can perform NR V2X SL communication via unicast by using part of the resource pools in the preconfigured transmission resource pool and / or reception resource pool. For example, this IE can be the transmission resource pool v2x-CommTxPoolList or p2x-CommTxPoolList and / or v2x-CommRxPoolList or reception resource pool v2x-CommTxPoolList included in SL-V2X-Preconfiguration.

[0462] - IE including separate SL transmission / reception resource pool information by resource allocation mode (scheduled resource allocation (mode 1 or mode 3) or UE autonomous resource selection (mode 2 or mode 4)).

[0463] ■When this IE is empty (not present), the two UEs may implicitly determine that the NR V2X SL communication will be performed via unicast using preconfigured transmit resources and / or receive resources.

[0464] In step 3c-40, when a V2X packet is generated, the vehicle terminal 3c-01 performs NR V2X SL unicast with another vehicle terminal or pedestrian mobile terminal 3c-02 by using a preconfigured transmission resource pool and / or reception resource pool.

[0465] Figure 3D is a signal flow diagram illustrating a process of performing NR V2X SL unicast communication via a pre-configured transmit resource pool and / or receive resource pool in an inter-UE autonomous resource selection mode according to an embodiment.

[0466] refer to Figure 3D In step 3d-05, the vehicle terminal 3d-01 performs a discovery process with another vehicle terminal or a pedestrian mobile terminal 3d-02, and in step 3d-10, performs a unicast link establishment process for NR V2X SL communication. The unicast link establishment process can be performed via the above-mentioned embodiments of the present disclosure.

[0467] When the V2X packet is generated in step 3d-15, the vehicle terminal 3d-01 performs NR V2X SL unicast with another vehicle terminal or pedestrian mobile terminal 3d-02.

[0468] When operating in UE autonomous resource selection mode (mode 2 or mode 4), the vehicle terminal 3d-01 can perform V2X SL unicast data transmission and reception with another vehicle terminal or pedestrian mobile terminal 3d-02 by using the system information or RRC message (e.g., RRCReconfiguration message) sent by the base station 3d-03 in step 3d-20 and / or the SL transmission and reception resource pool received via the inter-UE PC5-RRC message in step 3d-25. Steps 3d-20 and / or 3d-25 can be performed before step 3d-15.

[0469] In order to perform NR V2X SL unicast communication through a preconfigured transmission resource pool and / or reception resource pool based on the UE autonomous resource selection mode, the vehicle terminal 3d-01 may send a PC5-RRC message or a PC5-MAC CE to another vehicle terminal or a pedestrian mobile terminal 3d-02 (step 3d-35). NR V2X SL unicast communication is performed through a preconfigured transmission resource pool and / or reception resource pool in the UE autonomous resource selection mode due to one or more of the following reasons:

[0470] -When a UE in RRC connected mode transitions to RRC inactive mode or RRC idle mode. For example,

[0471] ■When receiving the RRCRelease message from the base station,

[0472] ■When the RRC reconfiguration process fails (Reconfiguration Failure), or

[0473] ■When an RRCReject message is received from the base station.

[0474] -Beyond the coverage of E-UTRA / NR

[0475] The PC5-RRC message or PC5 MAC CE message may include some or all of the following information:

[0476] - An indicator or IE that explicitly indicates whether to use reconfiguration of the sending resource pool and / or receiving resource pool.

[0477] ■Through the indicator or IE, the two UEs may determine that the V2X data packets are to be transmitted and received via NR V2X SL unicast by using the preconfigured transmit resource pool and / or receive resource pool. For example, the indicator or IE may be expressed in the form of true / false or Boolean, or in the form of an integer or enumeration.

[0478] ■For example, the pre-configured transmission resource pool may represent v2x-CommTxPoolList or p2x-CommTxPoolList included in the SL-V2X-Preconfiguration IE, and the pre-configured reception resource pool may represent v2x-CommRxPoolList included in the SL-V2X-Preconfiguration IE.

[0479] -Pre-configure part of the resource pool information IE in the sending resource pool and / or the receiving resource pool.

[0480] ■Through this IE, two UEs can perform NR V2X SL communication via unicast by using part of the resource pools in the preconfigured transmission resource pool and / or reception resource pool. For example, this IE can be the transmission resource pool v2x-CommTxPoolList or p2x-CommTxPoolList and / or v2x-CommRxPoolList or reception resource pool v2x-CommTxPoolList included in SL-V2X-Preconfiguration.

[0481] - IE including separate SL transmission / reception resource pool information by resource allocation mode (scheduled resource allocation (mode 1 or mode 3) or UE autonomous resource selection (mode 2 or mode 4)).

[0482] ■When this IE is empty (not present), the two UEs may implicitly determine that the NR V2X SL communication will be performed via unicast using preconfigured transmit resources and / or receive resources.

[0483] In step 3d-40, when a V2X packet is generated, the vehicle terminal 3d-01 can perform NR V2X SL unicast with another vehicle terminal or pedestrian mobile terminal 3d-02 by using a preconfigured sending resource pool and / or receiving resource pool.

[0484] Figure 3E A UE according to an embodiment is shown.

[0485] refer to Figure 3E , the UE includes a radio frequency (RF) processor 3e-10, a baseband processor 3e-20, a storage device 3e-30, and a controller 3e-40. The RF processor 3e-10 can perform functions such as frequency band conversion, amplification, etc. of signals sent and received via a radio channel. In other words, the RF processor 3e-10 can up-convert the baseband signal provided from the baseband processor 3e-20 to an RF band signal, and then send the RF band signal through an antenna, and can down-convert the RF band signal received by the antenna to a baseband signal. For example, the RF processor 3e-10 may 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). Although only a single antenna is shown in FIG. 3e, the UE may include multiple antennas. In addition, the RF processor 3e-10 may include multiple RF chains. In addition, the RF processor 3e-10 may perform beamforming. For beamforming, the RF processor 3e-10 may adjust the phase and amplitude of the signal sent or received by multiple antennas or antenna elements. The RF processor 3e-10 can perform MIMO and can receive multiple layers of data in MIMO operation. Under the control of the controller 3e-40, the RF processor 3e-10 can perform receive beam scanning by appropriately configuring multiple antennas or antenna elements, or adjust the direction and beam width of the receive beam to coordinate with the transmit beam.

[0486] The baseband processor 3e-20 can convert between baseband signals and bit streams based on the physical layer specifications of the system. For example, for data transmission, the baseband processor 3e-20 can generate complex symbols by encoding and modulating the transmission bit stream. For data reception, the baseband processor 3e-20 can reconstruct the received bit stream by demodulating and decoding the baseband signal provided from the RF processor 3e-10. For example, according to the OFDM scheme, for data transmission, the baseband processor 3e-20 can generate complex symbols by encoding and modulating the transmission bit stream, map the complex symbols to subcarriers, and then configure OFDM symbols by performing an inverse fast Fourier transform (IFFT) operation and a cyclic prefix (CP) insertion. For data reception, the baseband processor 3e-20 can divide the baseband signal provided from the RF processor 3e-10 in units of OFDM symbols, reconstruct the signal mapped to the subcarrier by performing a fast Fourier transform (FFT) operation, and then reconstruct the received bit stream by demodulating and decoding the signal.

[0487] The baseband processor 3e-20 and the RF processor 3e-10 can send and receive signals as described above. Therefore, each of the baseband processor 3e-20 and the RF processor 3e-10 can be referred to as a transmitter, a receiver, a transceiver, or a communicator. At least one of the baseband processor 3e-20 or the RF processor 3e-10 may include a plurality of communication modules to support a variety of different radio access technologies. In addition, at least one of the baseband processor 3e-20 or the RF processor 3e-10 may include a plurality of communication modules to process signals of different frequency bands. For example, different radio access technologies may include LTE networks, NR networks, and the like. Different frequency bands may include ultra-high frequency (SHF) (e.g., 2.5 GHz and 5 GHz) bands and millimeter wave (e.g., 60 GHz) bands.

[0488] The storage device 3e-30 can store data used for the above-mentioned base station operation, such as basic programs, applications and configuration information. The storage device 3e-30 can provide the stored data according to the request of the controller 3e-40.

[0489] The controller 3e-40 can control the overall operation of the UE. For example, the controller 3e-40 can send and receive signals through the baseband processor 3e-20 and the RF processor 3e-10. The controller 3e-40 can record data on the storage device 3e-30 and read data from the storage device 3e-30. In this regard, the controller 3e-40 may include at least one processor. For example, the controller 3e-40 may include a communication processor (CP) that performs communication control and an application processor (AP) that controls a higher layer (such as an application). The controller 3e-40 may include a multi-connection processor 3e-42 that executes a process for operating in a multi-connection mode.

[0490] Figure 3F A base station according to an embodiment is shown.

[0491] refer to Figure 3F The base station may include at least one transmit receive point (TRP). The base station includes an RF processor 3f-10, a baseband processor 3f-20, a communicator 3f-30, a storage device 3f-40 and a controller 3f-50.

[0492] The RF processor 3f-10 can perform functions such as signal band conversion and amplification for sending and receiving signals through a radio channel. In other words, the RF processor 3f-10 up-converts the baseband signal provided by the baseband processor 3f-20 into an RF band signal, and then sends the RF band signal through an antenna, and can down-convert the RF band signal received through the antenna into a baseband signal. For example, the RF processor 3f-10 may include a transmission filter, a reception filter, an amplifier, a mixer, an oscillator, a DAC, and an ADC.

[0493] Despite Figure 3F Only a single antenna is shown in FIG. 1 , but a base station may include multiple antennas.

[0494] In addition, the RF processor 3f-10 may include multiple RF chains. In addition, the RF processor 3f-10 may perform beamforming. For beamforming, the RF processor 3f-10 may adjust the phase and amplitude of a signal sent or received through multiple antennas or antenna elements. The RF processor 3f-10 may perform DL MIMO operations by transmitting at least one layer.

[0495] The baseband processor 3f-20 can convert between baseband signals and bit streams based on the physical layer specifications of the first radio access technology. For example, for data transmission, the baseband processor 3f-20 can generate complex symbols by encoding and modulating the transmitted bit stream. For data reception, the baseband processor 3f-20 can reconstruct the received bit stream by demodulating and decoding the baseband signal provided from the RF processor 3f-10. For example, according to the OFDM scheme, for data transmission, the baseband processor 3f-20 can generate complex symbols by encoding and modulating the transmitted bit stream, map the complex symbols to subcarriers, and then configure the OFDM symbols via IFFT and CP insertion.

[0496] For data reception, the baseband processor 3f-20 can divide the baseband signal provided from the RF processor 3f-10 in units of OFDM symbols, reconstruct the signal mapped to the subcarriers by performing FFT, and then reconstruct the received bit stream by demodulating and decoding the signal. The baseband processor 3f-20 and the RF processor 3f-10 can send and receive signals as described above.

[0497] Thus, each of the baseband processor 3f-20 and the RF processor 3f-10 may be referred to as a transmitter, a receiver, a transceiver, a communicator, or a wireless communicator.

[0498] The communicator 3f-30 can provide an interface for communicating with other nodes in the network. For example, the communicator 3f-30 can convert a bit string sent from a base station to another node (such as an auxiliary base station or a core network) into a physical signal, and convert a physical signal received from another node into a bit string.

[0499] The storage device 3f-40 can store data used for the above-mentioned base station operation, such as basic programs, applications, and configuration information. In particular, the storage device 3f-40 can store information about the bearer allocated to the connected UE, the measurement report sent from the connected UE, etc. The storage device 3f-40 can store standard information for determining whether to provide multiple connections to the UE or release multiple connections from the UE. The storage device 3f-40 can provide the stored data according to the request of the controller 3f-50.

[0500] The controller 3f-50 can control the overall operation of the base station. For example, the controller 3f-50 can send and receive signals through the baseband processor 3f-20 and the RF processor 3f-10 or through the communicator 3f-30. The controller 3f-50 can record data on the storage device 3f-40 and read data from the storage device 3e-30. In this regard, the controller 3f-50 may include at least one processor. The controller 3f-50 may include a multi-connection processor 3f-52 that executes a process for operating in a multi-connection mode.

[0501] The methods according to the above-described embodiments of the present disclosure may be implemented in hardware, software, or a combination of hardware and software.

[0502] When these methods are implemented in software, a computer-readable recording medium having one or more programs (software modules) recorded thereon may be provided. One or more programs recorded on the computer-readable recording medium are configured to be executable by one or more processors in the device. One or more programs include instructions for executing the methods of the embodiments of the present disclosure described in the claims or detailed description.

[0503] The program (e.g., software module or software) may be stored in a random access memory (RAM), a nonvolatile memory including flash memory, a read-only memory (ROM), an electrically erasable programmable read-only memory (EEPROM), a magnetic disk storage device, a compact disk ROM (CD-ROM), a digital versatile disk (DVD), another type of optical storage device, or a cassette tape. Alternatively, the program may be stored in a storage system that includes a combination of some or all of the above memory devices. Furthermore, each memory device may include multiple.

[0504] The program may also be stored in an attachable storage device that can be accessed via a communication network such as the Internet, an intranet, a local area network (LAN), a wireless LAN (WLAN), or a storage area network (SAN), or a combination thereof. The storage device may be connected to an apparatus according to an embodiment of the present disclosure via an external port. Another storage device on the communication network may also be connected to an apparatus that performs an embodiment of the present disclosure.

[0505] In the above-mentioned embodiment of the present disclosure, according to the embodiment, the elements included in the present disclosure are expressed in singular or plural form. However, the singular or plural form is appropriately selected for the convenience of explanation, and the present disclosure is not limited thereto. Therefore, the elements expressed in plural form may also be configured as a single element, and the elements expressed in singular form may also be configured as multiple elements.

[0506] While the present disclosure has been particularly shown and described with reference to certain embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made without departing from the spirit and scope of the present disclosure as defined, for example, by the appended claims and their equivalents.

Claims

1. A method performed by a first terminal in a wireless communication system, the method comprising: Sending a sidelink radio resource control RRC message including configuration information related to the sidelink to the second terminal; as well as receiving, from the second terminal, a response message to the sidelink RRC message as a response to the sidelink RRC message, The response message includes a first response message or a second response message, and Wherein, when the second terminal cannot comply with the configuration information, the second response message is received.

2. The method according to claim 1, further comprising: A timer associated with the transmission of the sidelink RRC message is started.

3. The method according to claim 2, further comprising: When the first terminal receives the first response message or the second response message, the timer is stopped.

4. The method according to claim 1, further comprising: Based on a failure indication received from lower layers, the unicast link is released.

5. The method according to claim 4, wherein: In case the integrity check fails, the unicast link is released.

6. The method according to claim 4, wherein: Upon expiration of a timer associated with the transmission of the sidelink RRC message, the unicast link is released.

7. The method according to claim 4, wherein: The releasing of the unicast link includes: Sending a PC5 signaling message for releasing the unicast link to the second terminal.

8. A first terminal in a wireless communication system, the terminal comprising: Transceiver; and at least one processor coupled to the transceiver and configured to: sending a sidelink radio resource control (RRC) message including sidelink-related configuration information to the second terminal, and receiving, from the second terminal, a response message to the sidelink RRC message as a response to the sidelink RRC message, The response message includes a first response message or a second response message, and Wherein, when the second terminal cannot comply with the configuration information, the second response message is received.

9. The first terminal according to claim 8, wherein: The at least one processor is further configured to: A timer associated with transmission of the sidelink RRC message is started.

10. The first terminal according to claim 9, wherein: The at least one processor is further configured to: When the first terminal receives the first response message or the second response message, the timer is stopped.

11. The first terminal according to claim 8, wherein: The at least one processor is further configured to: Based on a failure indication received from lower layers, the unicast link is released.

12. The first terminal according to claim 11, wherein: In case the integrity check fails, the unicast link is released.

13. The first terminal according to claim 11, wherein: Upon expiration of a timer associated with the transmission of the sidelink RRC message, the unicast link is released.

14. The terminal according to claim 11, wherein: The at least one processor is further configured to: Sending a PC5 signaling message for releasing the unicast link to the second terminal.

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