Terminal and first base station in a wireless communication system and methods thereof

Abstract

The disclosure relates to a communication technology for converging IoT technology with a 5G communication system for supporting a higher data transmission rate beyond a 4G system and a system thereof. Based on the 5G communication technology and IoT-related technology, the disclosure can be applied to intelligent services (e.g., smart home, smart building, smart city, smart car or connected car, health care, digital education, retail business, security and safety-related services, etc.). According to one embodiment of the present invention, a method for a terminal to transmit data packets in a wireless communication system is provided. The method includes the steps of generating a data packet, determining whether to perform duplicated transmission on the data packet, and if it is determined to perform duplicated transmission on the data packet, generating at least two duplicate packets by duplicating the data packet, and transmitting the respective at least two duplicate packets to at least two base stations.

Description

[0001] This application is a divisional application of the patent application with application number 201880006857.0 and title "Method and apparatus for transmitting data packet in wireless communication system" filed on January 15, 2018. TECHNICAL FIELD

[0002] The present disclosure relates to a resource situation reporting scheme in idle mode for supporting vehicle-to-everything (V2X) reliability transmission. Specifically, the present disclosure relates to a method for a vehicle UE to report a resource situation used in idle mode in order to guarantee reliability of data transmission of a vehicle UE when the UE performing vehicle communication (e.g., connected car or V2X) enters idle mode to reduce power consumption in a wireless communication system. In the present disclosure, an example of idle mode can refer to radio resource control (RRC)-idle or RRC-inactive defined in 3GPP.

[0003] Further, the present disclosure relates to transmission and reception of a communication device in a communication system.

[0004] Further, the present disclosure relates to an event and a time-to-trigger (TTT) operation method for UE handover to overcome link instability. BACKGROUND

[0005] To meet increasing demand for wireless data traffic after commercialization of 4th-Generation (4G) communication systems, efforts are being made to develop an improved 5th-Generation (5G) or pre-5G communication system. For this reason, the 5G communication system or pre-5G communication system is also called a beyond 4G network communication system or a post LTE system.

[0006] To achieve high data transmission rates, the 5G communication system is considered to be implemented in a millimeter wave band (e.g., 60 GHz band). To reduce loss of electric waves and increase a transmission distance of the electric waves in the millimeter wave, beamforming, massive MIMO, full dimensional MIMO (FD-MIMO), array antenna, analog beam forming, and large scale antenna techniques are discussed in the 5G communication system.

[0007] Further, in order to improve the network of the system, technologies such as improved small cell, advanced small cell, cloud radio access network (cloud RAN), ultra-dense network, device-to-device communication (D2D), wireless backhaul, mobile network, cooperative communication, coordinated multi-point (CoMP), and reception interference cancellation are being developed in 5G communication systems. Further, in 5G systems, hybrid FSK and QAM modulation (FQAM) and sliding window superposition coding (SWSC), which are an advanced coding modulation (ACM) scheme, and filter bank multi-carrier (FBMC), a non-orthogonal multiple access (NOMA), and sparse code multiple access (SCMA) as an orthogonal multiple access (OMA) scheme are being developed.

[0008] Meanwhile, the Internet is evolving from the human-centered connection network in which people generate and consume information to the Internet of Things (IoT) in which information is exchanged and processed between distributed elements such as things. The Internet of Everything (IoE) technology in which the data processing technology is combined with the IoT technology through connection with a cloud server is now emerging. In order to implement the IoT, technology elements such as a sensing technology, a wired / wireless communication and network infrastructure, a service interface technology, and a security technology are required. Therefore, recent studies are conducted on the technology such as a sensor network, machine to machine (M2M), and machine type communication (MTC) for connection between objects. In the IoT environment, an intelligent Internet technology (IT) service can be provided to create a new value for human life by collecting and analyzing data generated from connected things. The IoT can be applied to a field such as a smart home, a smart building, a smart city, a smart car or connected cars, a smart grid, health care, a smart home appliance, and an advanced medical service through the convergence and combination between the existing information technology (IT) and various industries.

[0009] Therefore, various attempts to apply the 5G communication system to the IoT are being made. For example, the 5G communication technology such as a sensor network, machine to machine, and MTC is implemented by schemes such as beamforming, MIMO, and array antennas. The application of a cloud radio access network (cloud RAN), which is the above-described big data processing technology, can be said to be an example of convergence between the 5G technology and the IoT technology.

[0010] In the 5G system, support of various services is considered compared to the existing 4G system. For example, the most representative services can include enhanced mobile broadband (eMBB), ultra-reliable and low-latency communication (URLLC), massive machine type communication (mMTC), evolved multimedia broadcast / multicast service (eMBMS), etc. A system that provides an URLLC service can be referred to as an URLLC system, and a system that provides an eMBB service can be referred to as an eMBB system. Further, the service and the system can be used interchangeably. SUMMARY

[0011] TECHNICAL PROBLEM

[0012] The disclosure provides a method and apparatus for measuring a state of a resource used in an idle mode and reporting the measured state of the resource when a vehicle UE enters the idle mode in a vehicle communication system.

[0013] Further, the disclosure defines a condition or configuration method for duplicated transmission, and defines a procedure for preventing unnecessary duplicated transmission.

[0014] Further, the disclosure proposes a handover method which can reduce handover failure and ping-pong handover in a system requiring high reliability.

[0015] Solution

[0016] According to an embodiment of the disclosure, when a vehicle UE (or a UE installed inside a vehicle) enters an idle mode, the UE measures a state of a resource used in the idle mode, and reports the measured state to a base station. The base station re-adjusts resource allocation based on the state of the resource used by the vehicle UE in the idle mode.

[0017] According to another embodiment of the disclosure, a method for a UE to transmit data packets in a wireless communication system is provided. The method includes generating a data packet, identifying whether to perform duplicated transmission on the data packet, generating at least two duplicated packets by duplicating the data packet based on a determination of duplicated transmission to be performed on the data packet, and transmitting the at least two duplicated packets to at least two base stations, respectively.

[0018] According to still another embodiment of the disclosure, a terminal in a wireless communication system is provided. The UE includes a transceiver that transmits and receives signals, and a controller configured to generate a data packet, identify whether to perform duplicated transmission on the data packet, generate at least two duplicated packets by duplicating the data packet based on a determination of duplicated transmission to be performed on the data packet, and control the transceiver to transmit the at least two duplicated packets to at least two base stations, respectively.

[0019] According to yet another embodiment of the disclosure, a method performed by a terminal in a wireless communication system is provided, the method including receiving, from a first base station, a radio resource control (RRC) message including at least one packet data convergence protocol (PDCP) configuration information, the PDCP configuration information including PDCP duplication information, generating a first PDCP protocol data unit (PDU) and submitting the first PDCP PDU to a primary radio link control (RLC) entity, generating a second PDCP PDU and submitting the second PDCP PDU to a secondary RLC entity, wherein the second PDCP PDU is a duplicate of the first PDCP PDU, receiving, from the first base station, a first medium access control (MAC) control element (CE) to deactivate PDCP duplication for a data radio bearer (DRB) configured with the PDCP duplication, based on the first MAC CE to deactivate the PDCP duplication, dropping, at the secondary RLC entity, the second PDCP PDU, and transmitting, to the first base station, the first PDCP PDU.

[0020] According to yet another embodiment of the disclosure, a terminal in a wireless communication system is provided, the terminal including a transceiver configured to transmit and receive signals, and a controller coupled to the transceiver and configured to receive, from a first base station, a radio resource control (RRC) message including at least one packet data convergence protocol (PDCP) configuration information, the PDCP configuration information including PDCP duplication information, generate a first PDCP protocol data unit (PDU) and submit the first PDCP PDU to a primary radio link control (RLC) entity, generate a second PDCP PDU and submit the second PDCP PDU to a secondary RLC entity, wherein the second PDCP PDU is a duplicate of the first PDCP PDU, receive, from the first base station, a first medium access control (MAC) control element (CE) to deactivate PDCP duplication for a data radio bearer (DRB) configured with the PDCP duplication, based on the first MAC CE to deactivate the PDCP duplication, drop, at the secondary RLC entity, the second PDCP PDU, and transmit, to the first base station, the first PDCP PDU.

[0021] According to yet another embodiment of the disclosure, a method performed by a first base station in a wireless communication system is provided, the method including transmitting, to a terminal, a radio resource control (RRC) message including at least one packet data convergence protocol (PDCP) configuration information, the PDCP configuration information including PDCP duplication information, transmitting, to the terminal, a first medium access control (MAC) control element (CE) that deactivates PDCP duplication of a data radio bearer (DRB) configured with the PDCP duplication, and receiving, from the terminal via a primary radio link control (RLC) entity of the terminal, a first PDCP protocol data unit (PDU), wherein a first PDCP PDU is generated and submitted to the primary RLC entity, wherein a second PDCP PDU is generated and submitted to a secondary RLC entity, the second PDCP PDU being a duplicate of the first PDCP PDU, and wherein the second PDCP PDU is discarded at the secondary RLC entity based on the first MAC CE that deactivates the PDCP duplication.

[0022] According to yet another embodiment of the disclosure, a first base station in a wireless communication system is provided, the first base station including a transceiver configured to transmit and receive a signal, and a controller coupled to the transceiver and configured to transmit, to a terminal, a radio resource control (RRC) message including at least one packet data convergence protocol (PDCP) configuration information, the PDCP configuration information including PDCP duplication information, transmit, to the terminal, a first medium access control (MAC) control element (CE) that deactivates PDCP duplication of a data radio bearer (DRB) configured with the PDCP duplication, and receive, from the terminal via a primary radio link control (RLC) entity of the terminal, a first PDCP protocol data unit (PDU), wherein a first PDCP PDU is generated and submitted to the primary RLC entity, wherein a second PDCP PDU is generated and submitted to a secondary RLC entity, the second PDCP PDU being a duplicate of the first PDCP PDU, and wherein the second PDCP PDU is discarded at the secondary RLC entity based on the first MAC CE that deactivates the PDCP duplication.

[0023] Advantageous Effects

[0024] According to embodiments of the disclosure, an effect of improving reliability in data transmission between vehicles can be obtained. Further, an effect of reducing battery consumption of a UE because latency taken to acquire resources due to resource congestion or resource collision of the UE in an idle mode or a connected mode (RRC connected mode) is reduced by adjusting resource allocation used in the idle mode (RRC idle or RRC inactive) can be obtained.

[0025] Further, according to embodiments of the disclosure, efficient duplicated transmission is possible in a communication environment having several links.

[0026] Furthermore, embodiments of this disclosure can reduce handover latency and prepare for link loss attributable to sudden signal strength degradation. Therefore, a highly reliable handover method can be provided. Additionally, signaling overhead can be reduced by preventing unnecessary handovers. Attached Figure Description

[0027] Figure 1 This is a diagram illustrating an example of a method for a vehicle UE to use resources under the control of a base station.

[0028] Figure 2 This is a diagram illustrating an example of a method for a vehicle UE to use resources when it enters idle mode under the control of a base station.

[0029] Figure 3 This is a diagram illustrating a method for base station configuration via channel state measurement and reporting by the UE.

[0030] Figure 4 This is a diagram illustrating a method for a UE to determine and perform channel measurements after receiving a channel state measurement configuration message.

[0031] Figure 5 This is a diagram illustrating another example of a method for a UE to determine and perform channel measurements after receiving a channel state measurement configuration message.

[0032] Figure 6 A method for periodically measuring the channel for a UE is shown.

[0033] Figure 7 This illustrates a method for changing the measurement period before a given event occurs in a method for periodically measuring the channel for a UE.

[0034] Figure 8 This paper illustrates a method for changing the measurement period when a given event occurs in a method for periodically measuring the channel for a UE.

[0035] Figure 9 Options for operating the measurement interval in a method for measuring channel state in a UE are shown.

[0036] Figure 10 The following is shown in accordance with this disclosure: Figure 9 The operation of the UE in the embodiment.

[0037] Figure 11 A method for transmitting channel state reports for each UE during base station operation is shown.

[0038] Figure 12 A method for the UE to periodically report the channel state after the UE measures the channel state is shown.

[0039] Figure 13 A method for a UE to report channel status after the UE measures the channel status is shown.

[0040] Figure 14 An operation for a UE to selectively report channel status after the UE measures the channel status is shown.

[0041] Figure 15 A method for a UE to report channel status after a given timing if the UE reports channel status after the UE measures the channel status is shown.

[0042] Figure 16 A method for a UE to report measurement results after a radio resource connection is established between the base station and the UE if the UE reports measurement results after the UE measures the channel status is shown.

[0043] Figure 17 A method for a UE to report channel status before a radio resource connection is established between the base station and the UE if the UE reports measurement results after the UE measures the channel status is shown.

[0044] Figure 18 A method for a UE to report channel status using a configuration request message during a process in which a radio resource connection is established between the base station and the UE during a process in which the UE reports measurement results after the UE measures the channel status is shown.

[0045] Figure 19 A method for a UE to report channel status using a configuration complete message during a process in which a radio resource connection is established between the base station and the UE during a process in which the UE reports measurement results after the UE measures the channel status is shown.

[0046] Figure 20 An example of using resources according to the status of each UE under the control of a base station is shown.

[0047] Figure 21 A method for a UE in an idle state to transmit channel measurement results to a surrounding connected UE and for the surrounding connected UE to directly forward the channel measurement report to a base station is shown.

[0048] Figure 22 An example of a MAC CE configuration used between UE_1 and UE_2 for Figure 21 in an embodiment of

[0049] Figure 23 An example of a MAC subheader configuration used in an embodiment of Figure 21

[0050] ​Figure 24 Methods for an idle UE to send channel measurement results to surrounding connected UEs and for surrounding connected UEs to forward channel measurement reports to a base station through a V2X server are shown.

[0051] Figure 25 Methods for performing a transmission stage of a duplicate transmission are shown.

[0052] Figure 26 Methods for performing a transmission stage of a duplicate transmission for a base station split architecture are shown.

[0053] Figure 27 Methods for performing a transmission stage of a lower layer duplicate transmission are shown.

[0054] Figure 28 Methods for performing a transmission stage of a lower layer duplicate transmission for a base station split architecture are shown.

[0055] Figure 29 Conditions for performing a duplicate transmission are shown.

[0056] Figure 30 Methods for configuring a duplicate transmission in a bearer unit are shown.

[0057] Figure 31 Methods for sending a message to configure a bearer are shown.

[0058] Figure 32 Methods for sending a message to configure a cell for a duplicate transmission are shown.

[0059] Figure 33 Embodiments of a duplicate transmission using a duplicate timer are shown.

[0060] Figure 34 Embodiments of a duplicate transmission using a duplicate timer are shown.

[0061] Figure 35 Examples of performing a duplicate transmission in a retransmission are shown.

[0062] Figure 36 Methods for a transmitter to send data including information indicating whether a duplicate transmission is to be performed when the transmitter sends data are shown.

[0063] Figure 37 A terminal sends information about a state of the terminal to a base station, and the base station configures a communication method based on the information is shown.

[0064] Figure 38 Methods for a transmission stage to perform a duplicate transmission when a radio bearer that forwards original packets and a radio bearer that forwards duplicate packets use the same radio interface are shown.

[0065] Figure 39 A method for performing duplicated transmission in the transmission phase is shown when the radio bearer forwarding original packets and the radio bearer forwarding duplicated packets use different radio interfaces.

[0066] Figure 40 A method for performing duplicated transmission in the transmission phase is shown when the radio bearer forwarding original packets and the radio bearer forwarding duplicated packets use different radio interfaces.

[0067] Figure 41 A method for configuring and performing duplicated transmission is shown.

[0068] Figure 42 A method for configuring and performing duplicated transmission is shown.

[0069] Figure 43 A correlation between Layer 1 (L1) samples, L1 outputs, and time windows is shown.

[0070] Figure 44 A sliding time window for Layer 1 filtering is shown.

[0071] Figure 45 A method for initial signal drop slope determination for network handover triggering for a UE is shown.

[0072] Figure 46 A method for continuous signal drop slope determination for network handover triggering for a UE is shown.

[0073] Figure 47 An example of a serving base station sending a measurement configuration to a UE and the UE performing a UE handover is shown.

[0074] Figure 48 An example of a serving base station sending a measurement configuration to a UE and the UE performing a network handover is shown.

[0075] Figure 49 An example of a UE detecting an event for handover and performing handover upon identifying a signal drop is shown.

[0076] Figure 50 An example of a UE detecting an event for handover and performing handover without a signal drop is shown.

[0077] Figure 51 An example of UE operation when the UE receives a handover command in a method for the UE to detect an event for handover and perform handover using a timer is shown.

[0078] Figure 52An example of the operation of a UE when the UE does not receive a handover command in a method in which the UE detects an event for handover and performs handover using a timer is shown.

[0079] Figure 53 is a diagram illustrating a UE according to an embodiment of the disclosure.

[0080] Figure 54 is a diagram illustrating a base station according to an embodiment of the disclosure. DETAILED DESCRIPTION

[0081] Hereinafter, embodiments of the disclosure are described in detail with reference to the accompanying drawings.

[0082] In describing embodiments, a description of the related art of the disclosure and the content known in the art that is not directly related to the disclosure is omitted in order to make the spirit of the disclosure clearer.

[0083] For the same reason, in the drawings, some elements are enlarged, omitted, or schematically shown. Also, the size of each element cannot accurately reflect its actual size. In the drawings, the same or similar elements are given the same reference numeral.

[0084] The advantages and characteristics of the disclosure and the method for achieving the advantages and characteristics will become more apparent from the embodiments described in detail in conjunction with the accompanying drawings. However, the disclosure is not limited to the disclosed embodiments, but can be implemented in various different ways. The embodiments are provided only to accomplish the disclosure and allow those skilled in the art to understand the category of the disclosure. The disclosure is defined by the category of the claims. Throughout the drawings, the same reference numerals will be used to denote the same or similar elements.

[0085] In the disclosure, it will be understood that each block of the flowchart illustrations and combinations of blocks in the flowchart illustrations can be run by computer program instructions. These computer program instructions can be installed on a processor of a general-purpose computer, a special-purpose computer, or other programmable data processing apparatus, so that the instructions run by the processor of the computer or other programmable data processing apparatus create a means for running the functions specified in the flowchart blocks. These computer program instructions can also be stored in a computer usable or computer readable memory that can instruct the computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer usable or computer readable memory produce an article of manufacture including an instruction means for implementing the functions specified in the flowchart blocks. The computer program instructions can also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer executable process that executes the instructions of the computer or other programmable apparatus to provide steps for running the functions described in the flowchart blocks.

[0086] Furthermore, each block of the flowchart illustrations can represent a module, segment, or portion of code, which comprises one or more executable instructions for implementing the specified logical function(s). It should also be noted that in some alternative implementations, the functions noted in the blocks can occur out of the order noted in the figures. For example, two blocks shown in succession may, in fact, be executed substantially concurrently or the blocks can sometimes be executed in the reverse order, depending upon the functionality involved.

[0087] In this case, the term "unit" used in the present embodiment means a software or hardware component such as a field programmable gate array (FPGA) or an application specific integrated circuit (ASIC), and the "unit" performs a specific function. The "unit" can be advantageously configured to reside on the addressable storage medium and configured to operate on one or more processors. Thus, the "unit" can include, for example, components such as software components, object-oriented software components, class components, and task components, processes, functions, attributes, procedures, subroutines, segments of program code, drivers, firmware, microcode, circuitry, data, databases, data structures, tables, arrays, and variables. The functions provided for the components and "units" can be combined into fewer components and "units" or further separated into additional components and "units". In addition, the components and "units" can be implemented to operate one or more CPUs in a device or a secure multimedia card. In addition, in one embodiment, the "unit" can include one or more processors. The "unit" can include one or more processors.

[0088] <Embodiment 1>

[0089] Hereinafter, operations of a base station and a UE managing idle mode resource congestion are described with reference to various embodiments.

[0090] An idle mode UE can refer to a UE operating in a radio resource control (RRC) idle mode or an RRC inactive mode, and a connected mode UE can refer to a UE operating in an RRC connected mode. In the present disclosure, reference is made to a UE operating in the RRC idle mode as an example of an idle mode UE, but the idle mode UE according to the embodiments of the present disclosure can include a UE operating in the RRC inactive mode. In addition, the present disclosure is described taking a vehicle UE as an example, but the embodiments of the present disclosure can be applied to a pedestrian UE or a road side unit (RSU) UE supporting a vehicle-to-everything (V2X) function.

[0091] Figure 1 is a diagram illustrating an example of a method for a vehicle UE to use resources under the control of a base station.

[0092] Reference is made to Figure 1Under the control of the base station, the UE is in an RRC connected mode or an RRC idle mode depending on the connection situation with the base station. In addition, the base station can allocate resources through which V2X data can be transmitted to the UE (UE1 to UE4) under the control of the base station.

[0093] For example, resource A can be a dedicated resource allocated to UE1 by the base station (e.g., eNB) so that UE1 can transmit V2X data in an RRC connected state. In this case, UE1 can use resource A in an RRC connected mode.

[0094] Resource B can be a common resource allocated to both UE2 and UE4 by the base station (e.g., eNB) available to both UE2 and UE4 so that UE2 and UE4 can transmit V2X data in an RRC connected state. If there is V2X data to be transmitted in an RRC connected state, UE2 and UE4 can use resource B by contention.

[0095] Resource C can be a common resource allocated by the base station (e.g., eNB) through which V2X data is transmitted by the UE in an RRC idle state. If there is V2X data to be transmitted in an RRC idle state, UE3 can use resource C.

[0096] Figure 2 is a diagram illustrating an example of a method for using resources when a vehicle UE enters an idle mode under the control of a base station.

[0097] Referring to Figure 2 , the UE can be converted from an RRC connected mode to an RRC idle mode under the control of the base station in order to reduce power consumption. In addition, the base station can allocate resources through which V2X data can be transmitted to the UE (UE1 to UE5) under the control of the base station.

[0098] For example, resource A can be a dedicated resource allocated to UE1 by the base station (e.g., eNB) so that UE1 can transmit V2X data in an RRC connected state. In this case, resource A is available only in an RRC connected state.

[0099] Resource B can be a common resource available to all UEs 1 to 5, which is allocated by the base station (e.g., eNB) and through which all UEs 1 to 5 can transmit V2X data in an RRC connected state. If there is V2X data to be transmitted in an RRC connected state, the UE can use resource B by contention.

[0100] The resource C can be a common resource available to all UEs 1 to 4, which is allocated by a base station (e.g., eNB), and through which a UE in an RRC idle state can transmit V2X data. If there is V2X data to be transmitted in the RRC idle state, the UEs 1 to 4 can use the resource C.

[0101] As the RRC idle UEs increase, the UEs attempting to use the resource C increase. Accordingly, when the resource C is used, the possibility of collision is higher.

[0102] Figure 3 is a diagram illustrating a method for a base station to configure a UE for channel state measurement and reporting.

[0103] Referring to Figure 3 , the eNB can transmit a channel state reporting configuration message (310) to the UE for indicating a method of measuring a channel (resource) state or a method of reporting a channel state.

[0104] To indicate a method of measuring and reporting a channel (resource) state with respect to the UE, the eNB can include resource pool information (e.g., resource pool ID or zone ID) in the channel state reporting configuration message.

[0105] Further, the channel state reporting configuration message can include information (e.g., support resource pool channel state reporting) indicating whether the UE needs to report channel (resource) state information with respect to a corresponding resource pool.

[0106] Further, the channel state reporting configuration message can include information on a threshold, which is a reference for reporting after the UE measures a channel (resource) state. For example, the threshold can be expressed in units of an energy value (dB). Further, the threshold can have one or more values.

[0107] Further, the channel state reporting configuration message can include information on a timing for measuring a channel (resource). The timing can be periodic timing or event-based timing. For example, when the eNB configures a measurement timing in the UE, the eNB can use the channel state reporting configuration message to configure that the UE should periodically measure a channel based on a paging period or a discontinuous reception (DRX) period. Alternatively, the eNB can include information for selectively measuring a channel by the UE based on a paging period or a DRX period in the channel state reporting configuration message. In another embodiment, the event-based timing can be configured as a case where a channel (resource) state energy value is a threshold or more or a case where a channel (resource) state energy value is a threshold or less.

[0108] Further, the channel state report configuration message can include information about timing for reporting a channel (resource) state of a measurement. For example, the eNB can include type information as information about a channel measurement report period (or timing) of the UE in the channel state report configuration message, indicating that the UE periodically reports a channel (resource) state based on a paging timing, or if there is data to be received at the paging timing, the UE should selectively report a channel (resource) state. If the channel (resource) state is periodically reported based on the paging timing, the period can be a paging period or a positive multiple of the paging period.

[0109] Further, the eNB can inform the UE of a duration for which a channel (resource) should be measured at a timing of measuring the channel (resource). For example, if the duration is set to 100 ms, the UE can measure a channel (resource) for 100 ms at the corresponding timing.

[0110] Alternatively, the eNB can use the channel state report configuration message to indicate a timing at which a channel (resource) should be measured or a timing at which measurement of a channel (resource) should be ended.

[0111] Figure 4 is a diagram illustrating a method for a UE to determine channel measurement and operation after receiving a channel state measurement configuration message.

[0112] Referring to Figure 4 After receiving the channel state measurement configuration message, the UE can identify a channel (resource) to be measured based on information included in the channel state measurement configuration message.

[0113] For example, when the UE receives a channel state measurement configuration message from a base station (410), the UE identifies whether resource information (e.g., resource pool information, resource ID) is included in the channel state measurement configuration message (420). When there is no resource information, the UE measures and reports a channel (resource) state about all V2X resources allocated by the base station (430). When the resource information is included, the UE can measure and report a channel (resource) state about only resources indicated by the resource information (440).

[0114] When the resource information is included in the channel state measurement configuration message and also includes information (e.g., a channel state report support indicator) indicating whether a corresponding resource situation should be measured and reported, the UE identifies whether the resource state must be reported (450), and then measures and reports a channel (resource) state of the corresponding resource.

[0115] In another embodiment, a case in which the resource information is not included in the channel state measurement configuration message and there is a channel state report support indicator can be considered.

[0116] Figure 5 is a diagram illustrating another example of a method for a UE to determine a channel measurement and operate after receiving a channel state measurement configuration message.

[0117] Referring to Figure 5 When the resource information is included in the channel state measurement configuration message, the UE can additionally determine the presence or absence of a channel state report support indicator (550). When the channel state report support indicator is configured, the UE measures a channel state of a resource indicated by the resource information of the channel state measurement configuration message and performs a channel report (540).

[0118] When the resource information is not present in the channel state measurement configuration message, the UE can additionally determine the presence or absence of a channel state report support indicator (560). When the channel state report support indicator is configured, the UE measures a channel state of all or a given resource and performs a channel report (530).

[0119] Figure 6 A method for a UE to periodically measure a channel is illustrated.

[0120] If the UE receives timing information in which a channel (resource) state measurement should be performed through a channel state report configuration message of the Figure 3 The present disclosure proposes that the UE autonomously determines a measurement timing and measures a channel (resource) state if the UE does not receive information about a measurement timing from the base station.

[0121] In an example of Figure 6 , the UE can periodically measure a channel (resource) state. For example, the UE can measure a channel (resource) state every timing from T1 to T5.

[0122] T1 to T5 can be a periodic timing determined based on paging or DRX included in channel measurement configuration information (or a channel state report configuration message) received from the base station. If the UE autonomously determines a measurement timing, the measurement timing can be a timing determined based on a paging period or a DRX period of system information received from the base station.

[0123] In addition, if paging or DRX is used to determine a measurement timing, the measurement timing can be a continuous paging or DRX period. For example, the UE can measure a channel state at T1, T2, T3, T4, and T5 timings.

[0124] In another embodiment, if paging or DRX is used to determine a measurement timing, the measurement timing is not continuous and can be a positive multiple of a paging or DRX period. For example, if a channel state is measured in a period that is twice a paging or DRX period, the UE can measure a channel state at T1, T3, and T5 timings.

[0125] Figure 7 A method of changing a measurement period before a given event occurs in a method for a UE to periodically measure a channel is shown.

[0126] The present disclosure proposes that in Figure 3 In the channel status report configuration message shown, when the UE receives information about the timing in which the channel (resource) status measurement should be performed or when no timing information is received from the eNB, the UE autonomously determines the timing of the channel (resource) status measurement and measures the channel (resource) status.

[0127] In Figure 7 In an example, the UE can selectively measure the channel (resource) status. For example, if the change in the measured channel status is not large when the UE measures the channel (resource) in T1 and T2 or an event for reporting the channel (resource) status measurement does not occur (e.g., when the channel busy status is greater than a given threshold Th1 or less than a given threshold Th2), the UE does not measure the channel (resource) status in T3, but can measure the channel (resource) status in T4.

[0128] In addition, if the change in the measured channel status is not large when the channel (resource) status is measured in T4 compared to the channel status measured in T1 and T2 or an event for reporting the channel (resource) status does not occur, the UE does not measure the channel (resource) status in T5 and T6, and can measure the channel (resource) status in T7. In this way, the UE can increase the measurement period when a given event regarding the channel (resource) status does not occur. The timing in which the UE does not perform the measurement can be increased only to a given timing (n). Information about the given timing (n) can be received from the eNB, or the UE can pre-store the given timing (n). For example, if the given timing (n) is 3, the UE can not perform at most 3 channel measurements based on the paging timing. Thereafter, the UE needs to measure the channel.

[0129] Figure 8 A method of changing a measurement period when a given event occurs in a method for a UE to periodically measure a channel is shown.

[0130] The present disclosure proposes that in Figure 3 In the channel status report configuration message shown, when the UE receives information about the timing in which the channel (resource) status measurement should be performed or when no timing information is received from the eNB, the UE autonomously determines the timing of the channel (resource) status measurement and measures the channel (resource) status.

[0131] In Figure 8 In an example, the UE can selectively measure the channel (resource) status.

[0132] For example, referring to the method of Figure 8 , if the difference in the channel (resource) measurement state is not large when the channel is measured in T1 or when no event for reporting the channel (resource) state measurement occurs, the UE does not measure the channel (resource) state in T2, T3, and T4, and can measure the channel (resource) state in T5. After the UE measures the channel (resource) state in T5, when an event that should report the channel (resource) state measurement occurs (for example, when the channel busy state is greater than or less than a given threshold Th1 or Th2 or more or less), the UE can periodically perform measurement during nD timing after T5. For example, if nD is 3, the UE can periodically measure the channel (resource) state in T6, T7, and T8.

[0133] The information about the given timing nD can be received from the eNB, or the UE can pre-store the information.

[0134] In addition, optionally, the information required for the channel (resource) state measurement (for example, the measurement timing T, the period nD that should perform measurement after the given timing) can be configured by the base station, or the UE can have previously stored the corresponding information.

[0135] Figure 9 Options for operating the measurement duration in the method for the UE to measure the channel state are shown.

[0136] The UE can receive information about the channel state measurement reference timing and / or the channel state measurement duration from the eNB. For example, the eNB can indicate T1 (for example, timing synchronized with a paging occasion, timing synchronized with a DRX cycle, timing synchronized with a paging cycle) as the channel measurement reference timing for the UE, and can indicate 100 ms as the channel state measurement duration

[0137] The UE can use the channel state measurement reference timing and the channel state measurement duration to identify the channel state measurement start timing and the channel state measurement end timing.

[0138] The implementation of the channel state measurement start timing and the channel state measurement end timing is, for example, as follows. In Figure 9 , Option 1 is the case where the UE measures the channel state during the previous duration from the channel state measurement reference timing. In this case, the channel measurement start timing T1_1 considering the duration can be obtained based on the difference between the channel state measurement reference timing T1 and the duration option 1 (D01). For example, the channel state measurement start timing T1_1 can be T1-D01. In addition, the channel state measurement end timing T1_2 can be T1.

[0139] In Figure 9Option 2 describes the scenario where the UE measures the channel state during a subsequent duration starting from the channel state measurement reference timing. In this case, the channel measurement start timing T1_1 can be the channel state measurement reference timing T1. Furthermore, the channel measurement end timing T1_2, which takes the duration into account, can be obtained by summing the channel measurement state reference timing T1 and the duration option 2 (D02). For example, the channel state measurement end timing T1_2 can be T1 + D02.

[0140] exist Figure 9 Option 3 involves measuring the channel state by considering the duration before and after the channel state measurement reference timing. In this case, the channel state measurement start timing T1_1', which considers the duration, can be obtained by using the difference between the channel state measurement reference timing T1 and the duration option 3 (D03). For example, the channel state measurement start timing T1_1' could be T1 - (D03 / 2). Furthermore, the channel state measurement end timing T1_2', which considers the duration, can be obtained by using the sum of the channel state measurement reference timing T1 and the duration option 3 (D03). For example, the channel state measurement end timing T1_2' could be T1 + (D03 / 2).

[0141] Duration option 1, duration option 2, and interval option 3 can be indicated by the eNB to the UE, or can be determined by the UE based on channel state measurement reference timing information and duration information.

[0142] Figure 10 The following is shown in accordance with this disclosure: Figure 9 The operation of the UE in the embodiment.

[0143] UE can be Figure 3 The UE configuration method (e.g., in a channel state configuration message) receives information about channel state measurement reference timing (e.g., paging timing) and information about measurement duration (1010). Based on at least one of the channel state measurement reference timing information and information about measurement duration or duration option, the UE can identify the measurement duration. Figure 9 In the embodiment, the timing (1020) for when the UE should start channel state measurement and when the UE should end channel state measurement.

[0144] The UE can receive duration options (1020) from the eNB for calculating the timing at which the UE should start channel state measurement and the timing at which the UE should end channel state measurement, or the UE may have previously stored this interval option.

[0145] After calculating the channel state measurement start timing and the channel state measurement end timing (1020), the UE operates in an idle mode (1030). The UE in the idle mode identifies whether the current timing is the channel state measurement start timing identified in step 1020 (1040). If the current timing is the channel state measurement start timing, the UE starts the channel state measurement (1050). If the current timing is not the channel state measurement start timing, the UE continues to operate in the idle mode (1030). After the UE starts the channel state measurement (1050), the UE identifies whether the current timing is the channel state measurement end timing identified in step 1020 (1060). If the current timing is the channel state measurement end timing, the UE ends the channel state measurement (1070). If the current timing is not the channel state measurement end timing, the UE continues to perform the channel state measurement (1050).

[0146] Figure 11 A method for eNB operation of channel state report transmission periods for each UE is shown.

[0147] Referring to the channel state report configuration method proposed in the present disclosure Figure 3 , the eNB can configure the UE to report the channel state periodically or based on an event. Further, referring to the embodiments of Figure 11 , the eNB provides information so that each UE has a different channel state report period and event timing. The UE can report the channel state at different timings.

[0148] The UE transmits the channel state report at different timings, and thus the eNB can receive the channel state report at consecutive timings.

[0149] For example, if UE1 is configured to transmit a channel state report to the eNB in T1 and T5, UE2 is configured to transmit a channel state report to the eNB in T2 and T6, UE3 is configured to transmit a channel state report to the eNB in T3 and T7, and UE4 is configured to transmit a channel state report to the eNB in T4 and T8, through channel measurement configuration information, the eNB can receive the channel state report consecutively from T1 to T8.

[0150] The paging period or the DRX period can be determined as the report timing so that the eNB can receive the channel state report consecutively because the UE reports the channel state at different timings.

[0151] Further, in order to make the UE report the channel state at different timings for each group, a group of UEs can be designated based on resources and the channel state report timing can be determined, or a group of UEs can be designated for each zone within the eNB and the channel state report timing can be determined.

[0152] Further, the channel status reporting timing can be configured based on a dedicated message or system information.

[0153] Figure 12 A method for a UE to periodically report channel status after the UE measures channel status is shown.

[0154] As shown in Figure 5 to Figure 9 , a UE can measure channel (resource) status and transmit the measurement result to an eNB.

[0155] When the UE receives a configuration type that a channel status report should be periodically transmitted in a channel status reporting configuration message from the eNB, Figure 3 the UE can periodically transmit channel status measurement results based on the configuration information.

[0156] For example, if the eNB has configured that channel status measurement should be periodically reported for the UE, the channel status measurement reporting method of the UE is as follows. If the channel measurement reporting timing of the UE has been configured as a paging timing period, timing 1 becomes a paging timing period. Figure 12 The UE can report channel status results measured in timing 1 to the eNB. Alternatively, the UE can report results measured in a given interval before timing 1 to the eNB.

[0157] The channel status report can include information such as a measured resource pool ID, a channel situation (e.g., busy, not busy, or a channel occupancy state (70%)).

[0158] Figure 13 A method for a UE to report channel status when an event occurs after the UE measures channel status is shown.

[0159] As shown in Figure 5 to Figure 9 , a UE can measure channel (resource) status and transmit the result (channel status report) to an eNB.

[0160] When the UE receives a configuration type that a channel status report should be selectively (based on an event) transmitted in a channel status reporting configuration message from the eNB, Figure 3 the UE can selectively transmit a channel status report based on channel status reporting configuration information provided by the eNB.

[0161] For example, in an embodiment of Figure 13 , if timing 1, timing 2, and timing 3 correspond to a paging period and the eNB configures channel status measurement timing based on the paging period, the UE can measure channel (resource) status in timing 1, timing 2, and timing 3.

[0162] The UE can identify whether there is data to be received from the eNB in timing 3 (for example, the UE identifies whether it will receive data by identifying a physical downlink control channel (PDCCH) and a radio resource control (RRC) message), and after receiving the paging, can transmit the measured channel (resource) result to the eNB in timing 3.

[0163] The channel status report can include information such as a measured resource pool ID, a channel situation (for example, busy, not busy, or a channel occupancy state (70%)).

[0164] Figure 14 Operations of a UE for selectively reporting a channel status after the UE measures a channel status (when an event occurs) are shown.

[0165] The UE can identify a measurement period (1410) in a channel status report configuration message of Figure 3 . For example, the measurement period can be a period based on a paging timing or can be a DRX period. If the current timing is the measurement period timing, the UE can measure a channel (resource) status (1420). After the UE measures the channel (resource) status (1420), the UE can identify whether an event that the channel (resource) status should be reported has occurred (1430).

[0166] For example, the channel status measurement configuration information received from the eNB can include a given threshold (Th1, Th2). When the channel measurement result is greater than the given threshold Th1 or less than the given threshold Th2 or when the channel measurement result is greater than the given threshold Th1 and less than the given threshold Th2, the UE can determine that an event that the channel measurement result should be reported has occurred.

[0167] If the event that the channel measurement result should be reported has occurred (1430) and the UE has checked that there is data to be received from the eNB (1440), for example, if the UE has checked that there is data to be received by identifying a PDCCH indicating a paging signal and an RRC message including the paging signal, the UE can transmit the channel status measurement result to the eNB (1450).

[0168] Figure 15 A method for a UE to report a channel status after a given timing if the UE reports the channel status after the UE measures a channel status when an event occurs is shown.

[0169] As shown in Figure 5 to Figure 9 , after measuring a channel (resource) status, the UE can transmit the result (channel status report) to the eNB.

[0170] If the UE is in Figure 3If the UE receives a configuration type in the channel state report configuration message indicating that channel state reports should be sent selectively (on an event basis), then the UE can selectively send channel state reports based on the channel state report configuration information provided by the eNB.

[0171] For example, in Figure 15 In one embodiment, if timing 1, timing 2, and timing 3 correspond to a paging period and the eNB configures channel state measurement timing based on the paging period, the UE can measure the channel (resource) state during timing 1, timing 2, and timing 3. The UE can identify whether there is data to be received from the eNB during timing 3 (e.g., the UE identifies the presence of data to be received by identifying PDCCH and RRC messages), and can send the channel (resource) measurement results (channel state report) to the eNB after timing 3 for a given nd (e.g., during timings 4 and 5 when nd is 2). In another embodiment, after timing 3, the UE can send the channel (resource) measurement results to the eNB during a corresponding time period after a given nd (e.g., during timing 5 when nd is 2).

[0172] Channel status reports can include information such as the measured resource pool ID, channel status (e.g., busy, not busy, or channel occupancy status (70%)).

[0173] Figure 16 This paper illustrates a method for the UE to report measurement results after establishing a radio resource connection between the eNB and the UE, if the UE reports the measurement results after measuring the channel state.

[0174] like Figure 3 to Figure 15 As shown, the UE can report the measurement results to the eNB after measuring the channel state. To report the measurement results, the UE switches from idle mode to connected mode, and the UE has the resources allocated to it.

[0175] Specifically, refer to Figure 16 The UE identifies whether the channel is already occupied (1610). An idle UE can initiate a random access operation for connection with the eNB (1620). The UE performs uplink synchronization with the eNB by executing the random access operation (1620) and transitions to RRC connection mode through the RRC connection establishment procedure (1630). Thereafter, the UE receives uplink resources allocated by the eNB for channel result reporting and can report the channel status (1640).

[0176] In addition, channel state reports can be sent via measurement report messages (i.e., one of the RRC messages), or they can be sent as separate RRC messages or separate MAC control element (CE) messages.

[0177] Figure 17 A method for a UE to report a channel status is shown if the UE reports the measurement results after the UE measures the channel status before a radio resource connection is established between the eNB and the UE.

[0178] As shown in Figure 3 to Figure 15 , after the UE measures the channel status, the UE can send the measurement results to the eNB. To report the measurement results, the UE transitions from an idle mode to a connected mode and the UE has resources allocated to it.

[0179] In particular, referring to Figure 17 , the UE identifies whether the channel is occupied (1710). The UE in an idle state can send a channel status report through some connection establishment procedure for a connection with the eNB. Some connection establishment procedures can include a step of sending an uplink resource during a random access procedure. For example, the UE can send a random access preamble to the eNB (1720). The eNB can use the random access preamble to identify an uplink timing and can inform the UE of the allocated uplink resource through a random access response by allocating an uplink resource available to the UE (1730).

[0180] After receiving the random access response, the UE can send the channel (resource) status measurement results to the eNB through the allocated uplink resource (1740).

[0181] Thereafter, the UE can perform an RRC connection establishment procedure with the eNB (1750).

[0182] Figure 18 A method for a UE to report a channel status using a configuration request message is shown in a procedure for establishing a radio resource connection between an eNB and the UE if the UE reports the measurement results after the UE measures the channel status.

[0183] As shown in Figure 3 to Figure 15 , after the UE measures the channel status, it can report the measurement results to the eNB. To report the measurement results, the UE transitions from an idle mode to a connected mode and the UE has resources allocated to it.

[0184] In particular, referring to Figure 18, the UE identifies whether the channel has been occupied (1810). The UE in the idle state can start a random access operation for connection with the eNB (1820). The UE can perform uplink synchronization with the eNB by performing the random access operation (1820), and then can transition to the RRC connected mode through an RRC connection establishment procedure (1830 to 1850). For example, the UE transmits an RRC connection request message to the eNB (1830). In response thereto, the eNB transmits an RRC connection setup message to the UE (1840). Finally, the UE transmits an RRC connection complete message to the eNB (1850).

[0185] In an embodiment of the disclosure, Figure 18 , the UE can transmit the reported channel (resource) measurement result to the eNB through the RRC connection request message in the RRC connection establishment procedure (1830 to 1850).

[0186] Figure 19 A method for a UE to report a channel state using a configuration complete message in a procedure of establishing a radio resource connection between an eNB and the UE if the UE reports a measurement result after measuring a channel state of the UE is illustrated.

[0187] As illustrated in FIG. 19, Figure 3 to Figure 15 , after the UE measures a channel state, it can report a measurement result to the eNB. To report the measurement result, the UE transitions from an idle mode to a connected mode, and the UE has a resource allocated thereto.

[0188] Specifically, referring to FIG. 19, Figure 19 , the UE identifies whether the channel has been occupied (1910). The UE in the idle state can start a random access operation for connection with the eNB (1920). After the UE performs uplink synchronization with the eNB by performing the random access operation (1920), the UE can transition to the RRC connected mode through an RRC connection establishment procedure (1930 to 1950). For example, the UE transmits an RRC connection request message to the eNB (1930). In response thereto, the eNB transmits an RRC connection setup message to the UE (1940). Finally, the UE transmits an RRC connection complete message to the eNB (1950).

[0189] In an embodiment of the disclosure, Figure 19 , the UE can transmit the reported channel (resource) measurement result to the eNB through the RRC connection complete message in the RRC connection establishment procedure (1930 to 1950).

[0190] Figure 20 An example of using resources according to a state of each UE under the control of an eNB is illustrated.

[0191] Figure 20 Embodiments of the present disclosure show a state of resources used in the current V2X. For example, referring to Figure 20 , there are V2X UEs UE1 and UE2 in an RRC idle state, and there is a V2X UE UE3 in an RRC connected state. UE2 can transmit data to UE3 using a PC5 interface, or can receive data from UE.

[0192] For example, Tx pool 1 allocated by the eNB can be a common resource used by UE1 and UE2 in the RRC idle state, and Tx pool 2 can be a resource used by UE3 in the RRC connected state. In addition, the RX resource pool can be a resource that can be commonly received by UE1, UE2, and UE3. The V2X UE can receive data in the RRC connected state or the RRC idle state using the RX resource pool.

[0193] Figure 21 A method for an idle UE to transmit channel measurement results to surrounding connected UEs and for the surrounding connected UEs to forward the channel measurement report directly to the eNB is shown.

[0194] In embodiments of the present disclosure, Figure 21 UE_1 is a V2X UE in an RRC idle state, and UE_2 is a V2X UE in an RRC connected state.

[0195] As shown in Figure 3 to Figure 15 , after UE_1 measures the channel (resource) state, it can report the measurement results. UE_1 can transmit the measurement results to surrounding UEs using a channel for V2X (e.g., a PC5 interface). The UEs peripheral to UE_1 can receive the measurement results transmitted by UE_1. The measurement results transmitted by UE_1 can be included in an application signal, a MAC subheader, or a MAC CE and transmitted.

[0196] The UE can identify whether the channel measurement results are included in the application signal, the MAC subheader, or the MAC CE.

[0197] Upon receiving the channel measurement results from UE_1 (2110), UE_2 determines whether to forward the channel measurement results to the eNB (2120). If a channel measurement result forwarding condition is satisfied, UE_2 can forward the channel measurement results received from UE_1 to the eNB (2130).

[0198] The channel measurement result forwarding condition can include at least one of a case where UE_2 is in a connected state, a case where UE_2 has a measured resource pool, a case where channel measurement results have been received from UE_1 for a given number or more, a case where UE_2 is a V-UE (vehicle UE), or a case where UE_2 is a P-UE (pedestrian UE) capable of partial sensing.

[0199] If the forwarding of the channel measurement result is determined, UE_2 can transmit the channel measurement result of UE_1 to the eNB (2130). UE_2 can transmit the channel measurement result of UE_1 through an RRC message or a MAC CE message, such as a measurement report message.

[0200] Figure 22 An example of a MAC CE configuration between UE_1 and UE_2 used in an embodiment of Figure 21 An example of a MAC CE configuration between UE_1 and UE_2 used in an embodiment of

[0201] Referring to Figure 22 , the MAC CE configuration, for example, a V2X channel status report MAC CE, can include a resource ID and a channel busy ratio, and the corresponding contents can be configured individually or in multiple configurations. When the V2X channel status report MAC CE is received from another UE (UE_1), the corresponding UE (UE_2) can determine whether to forward the channel measurement result received in the V2X channel status report MAC CE to the eNB. The channel measurement result forwarding condition can include at least one of a case where the UE (UE_2) has a resource pool, a case where a given number or more of channel measurement results have been received from a different UE (UE_1), a case where the UE (UE_2) is a V-UE, or a case where the UE (UE_2) is a P-UE capable of partial sensing.

[0202] In addition, a logical channel ID (LCID) for V2X channel status reporting can be configured in the MAC for the V2X channel status report MAC CE.

[0203] Figure 23 An example of a MAC subheader configuration used in an embodiment of Figure 21 An example of a MAC subheader configuration used in an embodiment of

[0204] In an embodiment of Figure 23In the V2X MAC sub-header, V indicates version and R indicates reserved bits. For example, if the 4-bit V and 1-bit R are 11111, the corresponding message could be a V2X channel state report message that needs to be forwarded to the eNB. For example, if the version and reserved bits are 11111, the channel state report information may already be included in the MAC Service Data Unit (SDU). Alternatively, the version and reserved bits can indicate whether the MAC SDU includes a Cooperation-Aware Message (CAM) or a Distributed Environment Notification Message (DENM) as a channel state report. For example, the reason for using the channel state report can be defined as a DENM message format. In this case, the DENM message can include the channel state report in the reason and the channel state result in the sub-reason. Alternatively, the data can be configured with a MAC SDU, and the sub-header can indicate that the configured MAC SDU is a channel measurement result.

[0205] In another embodiment, if the reserved bit is 11110, the channel busy ratio, i.e., the measurement result of the UE's channel (resource), and the measured resource ID may have been included in the V2X MAC subheader.

[0206] Figure 24 Methods for an idle UE to send channel measurement results to surrounding connected UEs and for surrounding connected UEs to forward channel measurement reports to an eNB via a V2X server are illustrated.

[0207] exist Figure 24 In the embodiment, UE_1 is a V2X UE in the RRC idle state, and UE_2 is a V2X UE in the RRC connected state.

[0208] like Figure 3 to Figure 15 As shown, UE_1 can report measurement results of channel (resource) status. UE_1 can use a channel for V2X (e.g., PC5 interface) to send the measurement results to surrounding UEs (2410). UEs surrounding UE_1 can receive the measurement results (2410) sent by UE_1. The measurement results sent by UE_1 can be sent as V2X control messages or user data formats.

[0209] As an example of user data format, measurement results can be transmitted as CAM or DENM used in Intelligent Transportation Systems (ITS). The reason for using the channel state report can be defined in the DENM message format. In this case, the DENM message can include the channel state report in the reason and the channel state result in the sub-reason. Alternatively, the data can be configured with a MAC SDU, and the sub-header can indicate that the configured MAC SDU is a channel measurement result.

[0210] For example, if the MAC subheader includes information indicating that a channel measurement result has been included in the MAC SDU, a surrounding UE (UE_2) that has received the channel measurement result from the UE (UE_1) in the idle state can know whether the corresponding message should be forwarded to the V2X server based on the MAC subheader.

[0211] The channel measurement result forwarding condition can include at least one of a case where the UE_2 is in a connected state, a case where the UE_2 has a measured resource pool, a case where the channel measurement result has been received from the UE_1 for a given number or more, a case where the UE_2 is a V-UE, or a case where the UE_2 is a P-UE capable of partial sensing.

[0212] After the UE_2 determines to forward the channel measurement result to the V2X server (2420), the UE_2 can transmit the eNB ID to which the UE_2 is connected together with the channel measurement result to the V2X server (2430).

[0213] When the channel measurement result and the eNB ID transmitted by the UE_2 are received (2430), the V2X server can transmit the channel measurement result information to the eNB to which the UE_2 is connected based on the eNB ID (2440).

[0214] <Embodiment 2>

[0215] Figure 25 A method for a transmission phase to perform duplicated transmission is shown.

[0216] Reference Figure 25 A packet data convergence protocol (PDCP) protocol data unit (PDU) can be duplicated and transmitted based on long term evolution (LTE) dual connectivity. A transmitter can insert a PDCP header that arrives at the transmitter into a PDCP service data unit (SDU) to be transmitted, and then can transmit the packet to a master cell group (MCG) and a secondary cell group (SCG) by duplicating the packet. Thereafter, in each radio link control (RLC) sublayer, an RLC header is independently inserted, and a transmission procedure can be performed.

[0217] Figure 26 A method for a transmission phase to perform duplicated transmission is shown.

[0218] Reference Figure 26, the eNB functions have been divided and implemented as a central unit (CU) and a distributed unit (DU). Specifically, the PDCP is implemented in the CU, and the RLC is implemented in the DU. The RLC PDU can be duplicated and transmitted. The transmitter can insert the PDCP header that arrives at the transmitter into the PDCP SDU to be transmitted, and then can transmit the packet by duplicating the packet through multiple DUs (DU1 and DU2). Thereafter, in each radio link control (RLC) sublayer, the RLC header is independently inserted, and a transmission procedure can be performed.

[0219] Figure 27 A method for a transmission phase to perform lower layer duplication transmission is shown.

[0220] Referring to Figure 27 , the RLC PDU can be duplicated and transmitted based on LTE carrier aggregation (CA). After the transmitter inserts the PDCP header that arrives at the transmitter into the PDCP SDU to be transmitted and inserts some or all of the RLC header, the transmitter can transmit the packet by duplicating the packet through each carrier (two or more of PCell or SCell). In this case, some or all of the RLC header of the transmitted packet is the same.

[0221] Figure 28 A method for a transmission phase to perform lower layer duplication transmission is shown.

[0222] Referring to Figure 28 , the eNB functions have been divided and implemented as a CU and a DU. Specifically, the function for adding a fixed header of the PDCP and the RLC is implemented in the CU, and some of the remaining functions are implemented in the DU. The RLC PDU can be duplicated and transmitted. After the transmitter inserts the PDCP header that arrives at the transmitter into the PDCP SDU to be transmitted and inserts some or all of the RLC header, the transmitter can transmit the packet by duplicating the packet through multiple DUs (DU1 and DU2). Some or all of the RLC header of the transmitted packet is the same.

[0223] Figure 29 A condition to perform duplication transmission is shown.

[0224] Generally, if the channel state is good, the need for duplication transmission can be low. Therefore, in Figure 29In an embodiment of FIG. 29, it is assumed that the duplicate transmission is performed when the channel status is less than a given threshold. The transmitter performs the duplicate transmission only when the channel status value is less than a given threshold (2920), while monitoring the channel status (2910). If not, the transmitter does not perform the duplicate transmission (2930). The channel status value can be any one of a received power value such as a received signal strength indication (RSSI), a reference signal received power (RSRP), or a reference signal received quality (RSRQ) used in a communication network, or a channel status value such as a channel quality indicator (CQI) or a rank indicator (RI). The threshold value can be predetermined or can be configured in the communication network (eNB, etc.).

[0225] If two or more links performing the duplicate transmission have different channel statuses, a representative value of the channel status can be set to the minimum value or the maximum value of the channel status or a combination of the two values. Whether to perform the duplicate transmission can be determined based on the representative value.

[0226] Figure 30 A method of configuring a duplicate transmission in a bearer unit is shown.

[0227] Reference Figure 30 In an embodiment of FIG. 30, the UE identifies whether to allow the duplicate transmission for a corresponding bearer by identifying a bearer setup (3010). In this case, the bearer can be any one of various bearers based on LTE such as a data radio bearer (DRB), a signaling radio bearer (SRB), and an EPS bearer. The bearer setup can be identified based on the contents of a corresponding message when an RRC connection setup message, an RRC connection reestablishment message, or an RRC connection reconfiguration message is transmitted. If the duplicate transmission for the corresponding bearer is allowed, the transmitter can transmit the corresponding bearer by duplicating the corresponding bearer (3020). If not, the transmitter cannot randomly perform the duplicate transmission, can select only one path, and can perform transmission (3030).

[0228] Further, in some embodiments, the duplicate transmission can be performed only when the channel status value is less than the threshold with respect to a bearer configured to activate only the duplicate transmission based on the bearer setup, as in an embodiment of FIG. 29, but, in combination with an embodiment of FIG. 30, does not always perform the duplicate transmission and allows the duplicate transmission. Figure 30 Figure 29 In an embodiment of FIG. 29, it is assumed that the duplicate transmission is performed when the channel status is less than a given threshold. The transmitter performs the duplicate transmission only when the channel status value is less than a given threshold (2920), while monitoring the channel status (2910). If not, the transmitter does not perform the duplicate transmission (2930). The channel status value can be any one of a received power value such as a received signal strength indication (RSSI), a reference signal received power (RSRP), or a reference signal received quality (RSRQ) used in a communication network, or a channel status value such as a channel quality indicator (CQI) or a rank indicator (RI). The threshold value can be predetermined or can be configured in the communication network (eNB, etc.).

[0229] Figure 31 A method of transmitting a message configuring a bearer is shown.

[0230] Reference Figure 31 In an embodiment of FIG. 31, the base station transmits a bearer setup message to the terminal (3110).

[0231] ​The bearer setup message can include at least one of information indicating whether duplication transmission is allowed for a corresponding bearer, information about in which layer or sublayer duplication transmission is allowed (e.g., PDCP or RLC), information about a threshold of a channel state in which duplication transmission is allowed, information about a duplication discard timer, information about a quantity of channel states for duplication transmission, information about a maximum PDU (or SDU) size of a bearer, or information of a number of retransmissions when duplication transmission is performed.

[0232] The information indicating whether duplication transmission is allowed can indicate whether duplication transmission should always be performed, whether it can be determined whether duplication transmission will be performed if necessary, or whether duplication transmission is prohibited. In addition, the information indicating whether duplication transmission is allowed can indicate whether duplication transmission is allowed at an automatic repeat request (ARQ) or hybrid ARQ (HARQ) initial transmission or whether duplication transmission is allowed at an ARQ or HARQ retransmission.

[0233] The information about a quantity of channel states for duplication transmission can include RSRP, RSRQ, RSSI, or a modulation and coding scheme (MCS) index. In addition, the information about a quantity of channel states for duplication transmission can indicate which value of a minimum (min), a maximum (max), or an average value will be used.

[0234] The information about a number of retransmissions when duplication transmission is performed can indicate a number of retransmissions per or a total number of retransmissions.

[0235] The terminal and the base station can determine how duplication transmission will be performed based on Figure 31 a bearer setup message. The bearer setup message can be transmitted through an RRC connection setup, RRC connection reestablishment, or RRC connection reconfiguration message.

[0236] Figure 32 A method of transmitting a message to configure a cell for duplication transmission is shown.

[0237] Referring to Figure 32 , the base station transmits a cell configuration message to the terminal (3210). In this case, the cell can be a cell concept of LTE, a Pcell, an SCell, etc.

[0238] The cell configuration message can include at least one of information indicating whether duplication transmission is allowed, information about a threshold of a channel state in which duplication transmission is allowed, information about a duplication discard timer, information about a quantity of channel states for duplication transmission, information about a maximum PDU (or SDU) size of a cell, or information about a number of retransmissions when duplication transmission is performed.

[0239] The information indicating whether to allow duplicated transmission can indicate whether duplicated transmission should always be performed, whether it can be determined whether duplicated transmission will be performed if necessary, or whether duplicated transmission is prohibited. Also, the information indicating whether to allow duplicated transmission can indicate whether duplicated transmission is allowed at ARQ or HARQ initial transmission or whether duplicated transmission is allowed at ARQ or HARQ retransmission.

[0240] The information on the channel state amount for duplicated transmission can include RSRP, RSRQ, RSSI, or an MCS index. Also, the information on the channel state amount for duplicated transmission can indicate which of a minimum, a maximum, or an average value of several links will be used.

[0241] The information on the number of retransmissions when duplicated transmission is performed can indicate each retransmission number or a total retransmission number.

[0242] The terminal and the base station can determine how duplicated transmission will be performed based on a cell configuration message of Figure 31 The cell configuration message can be transmitted through an RRC connection setup, an RRC connection reestablishment, or an RRC connection reconfiguration message.

[0243] Figure 33 Embodiments of duplicated transmission using a duplicated timer are illustrated. Figure 34 Embodiments of duplicated transmission using a duplicated timer are illustrated.

[0244] When duplicated transmission is performed, the time taken to transmit data can be different due to a difference between times when physical resources (e.g., physical resource blocks (PRBs)) are allocated. When such a time difference occurs, if transmission of corresponding data is not performed through another path until the duplicated timer expires after a transmission timing operation of first transmitted data, data transmission can be configured not to be performed. If transmission of data does not satisfy a latency requirement after the duplicated timer expires, unnecessary transmission can be prevented. In Figure 33 In an example of Figure 34 In an example of

[0245] In the case of retransmission, retransmission is performed before the duplicated timer expires, but retransmission can not be performed after the duplicated timer expires.

[0246] Figure 35 Examples in which duplicated transmission is performed in retransmission are illustrated.

[0247] Re-transmission in ARQ or HARQ is performed based on reception of a negative acknowledgement (NACK) including that a NACK is considered to have been received although an ACK is not received within a given time. Figure 35 As shown in FIG. 6, if a NACK is received with respect to initially transmitted data, duplicated transmission can be performed on the corresponding data at retransmission.

[0248] Figure 36 A method for a transmitter to transmit data including information indicating whether duplicated transmission is to be performed when the transmitter transmits the data is shown.

[0249] If the transmitter performs duplicated transmission in a given case, it can be difficult for a receiver to know whether duplicated transmission is currently performed. In this case, the transmitter can transmit a header including data, the header including an indicator or index indicating that duplicated transmission is performed. The indicator can be a 1-bit indicator that distinguishes between a packet indicating that duplicated transmission is performed and a packet indicating that duplicated transmission is not performed, and can be information indicating how many duplicated transmissions are performed or where duplicated transmission is performed.

[0250] Figure 37 A terminal is shown to transmit information about a state of the terminal to a base station, and the base station configures a communication method based on the information.

[0251] Due to the implementation method, the size of data that the terminal can maximally transmit and receive can be limited. Only when the terminal transmits information about a state (e.g., capability) of the terminal to the base station (3710), the base station can establish a link connection (3720) considering the state of the terminal. The message for the state report of the terminal can be an RRC message. The message can include a buffer capacity of the terminal or information (e.g., an indicator) about a maximum data size that can be processed by the terminal. The base station can establish a connection (3720) with the terminal based on such a message, and can configure Figure 31 a maximum PDU (or SDU) size of a bearer setup message of Figure 32 a cell configuration message of. Furthermore, the base station can generate a downlink data packet by limiting a maximum PDU (or SDU) size based on the state of the terminal, and can transmit the downlink data packet to the terminal.

[0252] In new radio (NR), a technique for duplicating and transmitting a packet is discussed in order to improve reliability of data transmission. Accordingly, each entity of an access stratum (AS) duplicates a packet and transmits the duplicated packet using the same radio interface or different radio interfaces. A side that receives the duplicated packet identifies that the received packet has been duplicated according to the duplication method, removes remaining duplicated packets except for only one packet among the duplicated packets, and transmits the one packet to a higher layer.

[0253] Figure 38 A method for a transmission phase to perform duplicated transmission is shown when the radio bearer that forwards original packets and the radio bearer that forwards duplicated packets use the same radio interface.

[0254] Wherein the radio bearer that forwards original packets can be referred to as a primary radio bearer, and wherein the radio bearer that forwards duplicated packets can be referred to as a secondary radio bearer. The primary radio bearer and the secondary radio bearer can be referred to as a primary RLC bearer and a secondary RLC bearer. Furthermore, packet transmission can be performed regardless of whether duplicated transmission is performed for the primary radio bearer.

[0255] With reference to Figure 38 embodiments, duplication is performed in PDCP. The original packets and the duplicated packets can be sent to the eNB through the same radio interface. Furthermore, a given time delay that can be imposed between the packets forwarded as primary radio bearers and the packets forwarded as secondary radio bearers can be reduced with respect to the UE. The eNB that receives the duplicated packets is the same, and the duplicated packets can go through the same L1 / L2 stack.

[0256] Figure 39 A method for a transmission phase to perform duplicated transmission is shown when the radio bearer that forwards original packets and the radio bearer that forwards duplicated packets use different radio interfaces. Figure 40 A method for a transmission phase to perform duplicated transmission is shown when the radio bearer that forwards original packets and the radio bearer that forwards duplicated packets use different radio interfaces.

[0257] With reference to Figure 39 and Figure 40 embodiments, the primary radio bearer and the secondary radio bearer can use different radio interfaces. Specifically, Figure 39 A DC style is shown with different L1 / L2 stacks other than PDCP, and Figure 40 A CA style is shown where the L2 stack is shared other than the PHY. In the DC style, such as Figure 39 shown, the original packets and the duplicated packets can be sent per cell group. In the CA style, such as Figure 40 shown, the original packets and the duplicated packets can be sent per component carrier (CC).

[0258] In the case of Figure 40 , the primary radio bearer and the secondary radio bearer can be sent in different CCs. The L2 packets sent in each CC are the same, but the redundancy version of HARQ can be different for each CC. If the redundancy version of HARQ is different, the reception phase needs to aggregate the received transport blocks (TBs) through the HARQ algorithm.

[0259] When the eNB transmits a duplication transmission activation signal or a deactivation signal to the UE, the UE can perform duplication transmission or stop duplication transmission by considering the corresponding signal. The duplication transmission activation signal and the deactivation signal can be transmitted using a MAC CE, an RLC control PDU, a PDCP control PDU, an RRC connection reconfiguration message, or a DCI of a DL control channel.

[0260] The eNB can transmit the duplication transmission activation signal or the deactivation signal according to the following conditions.

[0261] First, this is a case in which duplication transmission is required to satisfy Ultra-Reliable and Low-Latency Communication (URLLC) requirements. When the service characteristics of a given UE are URLLC, the eNB transmits a duplication transmission activation signal, and when the URLLC service ends, the eNB transmits a duplication transmission deactivation signal.

[0262] Second, if the size of a packet is large, the signal quality is not good, there is a margin in another radio interface, i.e., a CC resource, or there is a margin in a cell group resource, the eNB can transmit a duplication activation signal.

[0263] Figure 41 A method of configuring and performing duplication transmission is shown. Figure 42 A method of configuring and performing duplication transmission is shown.

[0264] Figure 41 A case in which a base station controls duplication timing using an activation command is shown. Referring to Figure 41 , a first base station transmits a duplication capable bearer setup message to a terminal (4110). If it is identified that duplication conditions are satisfied, the first base station transmits a duplication activation command message to the terminal (4120). When the duplication activation command message is received, the terminal can start duplication transmission. The terminal transmits data to the first base station on a primary bearer (4130) and transmits data to a second base station on a secondary bearer (4140). If the duplication conditions are not satisfied during the duplication transmission is performed, the first base station transmits a duplication deactivation command message to the terminal (4150). When the duplication deactivation command message is received, the terminal stops performing duplication transmission. The terminal performing packet duplication transmission can mean that packets are transmitted from a PDCP layer of the terminal to two or more RLC or MAC layers. The terminal stopping performing duplication transmission can mean that packets are transmitted from the PDCP layer of the terminal to one RLC or MAC layer. The one RLC or MAC layer can be an RLC or MAC layer of the primary bearer.

[0265] Figure 42 A case in which a base station transmits an activation command including information about duplication conditions or duplication to a terminal and the terminal performs or stops duplication transmission based on the information about the duplication conditions or duplication is shown. Referring toFigure 42 The first base station transmits a duplication activation command message including information on a duplication condition or duplication to the terminal (4210). When the duplication condition is satisfied, the terminal can start duplication transmission. The terminal transmits data to the first base station on a primary bearer (4220) and transmits data to the second base station on a secondary bearer (4230). If the duplication condition is not satisfied while performing duplication transmission, the terminal stops performing packet transmission. The first base station transmits a duplication deactivation command message to the terminal (4240). The terminal performing packet duplication transmission can mean that packets are transmitted from the PDCP layer of the terminal to two or more RLC or MAC layers. The terminal stopping performing duplication transmission can mean that packets are transmitted from the PDCP layer of the terminal to one RLC or MAC layer. The one RLC or MAC layer can be an RLC or MAC layer of the primary bearer.

[0266] Figure 41 The information on the duplication condition identified by the base station in the embodiment of Figure 42 The duplication condition or duplication transmitted from the base station to the terminal in the embodiment can include the following. The duplication condition can include content on a duplication transmission execution time indicating whether duplication transmission will start now or will start after a given time. The duplication condition can include content on resources indicating where resources for duplication transmission are located (location based on time and frequency). The duplication condition can include a target to which duplication will be performed, indicating on which bearer or logical channel duplication transmission will be performed. The duplication condition can include information limiting available resources, indicating which CC will be used. For example, the information limiting available resources can indicate a given carrier of a CC included now as a carrier indicator field (CIF), such as CA, or can include a PCell or SCell ID. The information limiting available resources can include information indicating which SCG will be used, for example, an ID corresponding to the SCG. The duplication condition can include information on a layer performing duplication. For example, the duplication condition can include information providing notification of high-level duplication using an SCG, low-level duplication using a CC, duplication performed in a MAC, or duplication performed in a PHY. In addition, the PHY can transmit HARQ by retransmitting a duplicated packet in the case of feedback without a NACK packet. The duplication condition can include a threshold value of a packet size, such that duplication transmission is performed only when the packet size is the threshold value or more. The duplication condition can include a threshold value of a channel state, such that duplication transmission is performed only when the channel state of a serving cell is the threshold value or more.

[0267] The base station can perform a reception operation suitable for the capability or support optimal resource scheduling only when it knows the capability of the terminal with respect to duplicated transmission. The UE capability information message including information about the duplicated transmission capability of the terminal can include at least one of information about the size of a packet to be duplicated, information about an uplink bandwidth or a simultaneous reception bandwidth of the terminal capable of simultaneous transmission when different radio interfaces are used, a transmission power value that can be radiated to each radio interface when simultaneous transmission, or service information that can be accommodated by the corresponding terminal. For example, a terminal requiring a URLLC service can transmit service information that can be accommodated by the corresponding terminal to the base station. The base station can determine whether duplication of packets is required based on the information.

[0268] When the terminal establishes a bearer with the base station, it can establish a primary radio bearer and a secondary radio bearer, respectively. Alternatively, the terminal can establish a radio link to be primarily transmitted and a radio link to be secondarily transmitted on one radio bearer. In the present disclosure, the terms of the primary radio bearer and the secondary radio bearer are used for convenience of description.

[0269] After receiving the duplication deactivation command, the terminal continues to transmit data on the primary radio bearer, identifies a buffer of the secondary radio bearer with respect to the secondary radio bearer, and if there is a small amount of data in the buffer, can immediately discard the duplicated packets within the buffer, or if there is a large amount of data in the buffer, can transmit the packets that are now being transmitted and discard the remaining packets. Alternatively, the UE can transmit the packets that have been duplicated for both the primary bearer and the secondary bearer, and can transmit the original packets without duplicating the packets through a single radio interface after a timing at which the deactivation command is received.

[0270] In an embodiment of Figure 41 and Figure 42 , whether duplication transmission can be made can be configured at the time of establishing a bearer. The terminal can immediately perform duplication after establishing a bearer, and can perform duplication after receiving a duplication activation command. However, duplication is performed on the corresponding bearer or logical channel after receiving the duplication activation command. If a preparation time is required to perform duplication transmission, duplication can be performed after a given time. When a duplication deactivation command is received, the terminal does not perform duplication.

[0271] In an embodiment of Figure 41 and Figure 42 , a duplication activation command and a duplication condition can be combined and applied. In addition, the duplication condition can be included and configured in a bearer establishment or a duplication activation command.

[0272] <Embodiment 3>

[0273] The disclosure proposes a handover method capable of reducing handover (HO) failure and ping-pong in a system requiring high reliability. Embodiments of the disclosure can be used as a handover method for solving link instability in a high frequency system. The disclosure can provide an event and timing for a UE to determine to perform handover when it satisfies network handover and handover conditions to attach to a target cell, and the UE determines which type of handover will be performed when the UE attached to the target cell handovers coexist based on a handover command from the network.

[0274] For example, the disclosure can provide a method of requiring an event to first generate a handover type according to a situation of a UE by introducing a new measurement configuration factor (e.g., a slope), which is different from an existing handover method of starting handover based only on a current value of a received signal. According to the method proposed in the disclosure, unnecessary measurement reporting and handover signaling overhead due to unnecessary measurement reporting that can occur due to performing unnecessary handover can be prevented.

[0275] It is highly likely that network handover uses event A3 based on a relative value, and UE handover uses event A5 based on an absolute value. Event A3 and event A5 are the same as handover events used in an LTE system. When sudden signal quality degradation of a serving cell of a UE occurs in a high frequency system, event A3 and A5 occur almost simultaneously. Therefore, event A3 using a relative value is highly likely to occur earlier than event A5 based on a minimum value. Therefore, if a signal strength drops to a minimum quality or lower due to sudden occurrence of signal degradation, UE handover using event A5 can occur, but network handover using event A3 can be first triggered. In this case, there is a problem in that it can be unnecessary to perform measurement reporting and handover-related signaling for performing network handover of a serving eNB and a target eNB.

[0276] Figure 43 Correlation between layer 1 (L1) samples, L1 output, and time window is shown.

[0277] Figure 43 The time window of is not contiguous in time. Each L1 sample can be a value per beam, or can be an average or linear sum of values for a given beam. The values can be measured based on a reference signal per beam, or can be measured based on a UE-specific reference signal. The UE can derive one value by averaging or linearly summing the L1 sample values during the time window. The derived value can be defined as the L1 output. In this case, the time window can be contiguous in time, or can be non-contiguous in time. In the case of a non-contiguous time window, the L1 output occurs in the time window period. In the case of L3 filtering, the UE can derive one L3 output by weighted summing two consecutive L1 outputs, and can consider the L3 output in determining a handover event.

[0278] Figure 44 A sliding time window is shown for layer 1 filtering.

[0279] Configured in a partially continuous sliding window format Figure 44 The time window. In this case, the L1 output occurs within the same time period as the L1 sampling. The L1 output can occur within a given time period. An L3 filtered value is generated for each L1 output via L3 filtering. According to the Radio Resource Management (RRM) method, the measurement can be either the L1 output or the L3 filtered value.

[0280] In embodiments of this disclosure, the method for setting the slope value to be applied when performing a handover for the serving eNB is as follows.

[0281] The serving eNB can configure events, slope values, and two Time-to-Trigger (TTI) values ​​for Type 1 handover. Type 1 handover can include either network handover or UE handover. The slope value can be used as a condition for the UE to determine the TTT value to use. Each of the two TTT values ​​can be applied when the difference between two time-continuous measurements (which can be L1 or L3 output values ​​according to the RRM method) measured by the UE is greater than or less than the slope value. The set of parameters configured in the UE by the serving eNB can be {a, TTT1, TTT2}. In this case, “a” is the slope value and can be in dBm / ms, W / ms, or mW / ms. The UE can determine whether the slope of the received signal strength reduction is greater than the slope value “a” by comparing the current L3 value with the previous L3 value, based on how much the received signal strength has decreased.

[0282] According to embodiments of this disclosure, the entry conditions for a UE to begin handover can satisfy the following two conditions. If a Type 1 handover event (either for network handover or UE handover) is triggered and the increase or decrease in the L3 output value during the L3 output period by comparing t0 (the L3 output value before the current step) and t1 (the current L3 output value) is greater than a threshold "a", then the UE can perform a Type 2 handover event by applying TTT2. If a Type 1 event (either for network handover or UE handover) is triggered and the L3 output value by comparing t0 (the L3 output value before the current step) and t1 (the current L3 output value) is less than a threshold "a", then the UE can perform a Type 1 handover event by applying TTT1. The L3 output value can be a value converted in milliseconds.

[0283] Events used in LTE systems can be applied to Type 1 handover events. In LTE systems, a UE can use a measurement report trigger event to report measurements to the eNB. For example, if the eNB is configured to use a measurement report trigger event as A1, the UE can configure the difference between the serving eNB's measurement signal and a given offset to be greater than a given threshold as an entry condition. Furthermore, the UE can configure the sum of the serving eNB's measurement signal and a given offset to be less than a given threshold as a departure condition. The given offset value can include hysteresis offset, etc.

[0284] In another embodiment, if the eNB is configured that the UE should use a measurement report trigger event as A2, the UE can configure the sum of the serving eNB's measurement signal and a given offset to be less than a given threshold as an entry condition. Furthermore, the UE can configure the difference between the serving eNB's measurement signal and the given offset to be greater than a given threshold as a departure condition. The given offset value may include hysteresis offset, etc.

[0285] In another embodiment, if the eNB is configured that the UE should use the measurement report trigger event as A3, the UE can configure the sum of the measurement signal of the neighboring eNB and the given offset Of_1 to be greater than the sum of the measurement signal of the serving eNB and the given offset Of_2 as an entry condition. Furthermore, the UE can configure the sum of the measurement signal of the neighboring eNB and the given offset Of_1 to be less than the sum of the measurement signal of the serving eNB and the given offset Of_2 as a departure condition. The given offset Of_1 and the given offset Of_2 may include frequency-dependent offsets, cell-dependent offsets, or hysteresis offsets.

[0286] In another embodiment, if the eNB is configured to use the measurement report trigger event as A4, the UE can configure the sum of the measurement signal of the neighboring eNB and a given offset of_1 to be greater than a given threshold as an entry condition. Furthermore, the UE can configure the sum of the measurement signal of the neighboring eNB and a given offset of_2 to be less than a given threshold as a departure condition. The given offset of_1 and given offset of_2 may include frequency-dependent offsets, cell-dependent offsets, or hysteresis offsets.

[0287] In another embodiment, if the eNB is configured that the UE should use a measurement report trigger event as A5, the UE can configure an entry condition where the sum of the serving eNB's measurement signal and a given offset of_1 is less than a given threshold Th1 and the sum of the neighboring eNB's measurement signal and a given offset of_2 is greater than a given threshold Th2. Furthermore, the UE can configure a departure condition where the difference between the serving eNB's measurement signal and a given offset of_1 is greater than a given threshold Th1 and the sum of the neighboring eNB's measurement signal and a given offset of_3 is less than a given threshold Th2. The given offset of_1 may include a hysteresis offset, and the given offsets of_2 and_3 may include frequency-dependent offsets, cell-dependent offsets, or hysteresis offsets.

[0288] Figure 45 A method for determining the initial signal descent slope for network handover triggering of a UE is shown.

[0289] exist Figure 45 In this embodiment, Type 1 handover can signify network handover. The UE identifies the Type 1 handover event and the slope of each L3 output time. That is, the UE identifies whether the decrease in the L3 output value adjacent to the Type 1 handover event is greater than or less than a given threshold. For example, when the Type 1 handover event condition meets the entry condition, the UE identifies whether the decrease from the L3 output value one step prior to the L3 output value at the corresponding time is greater than or less than the product of the threshold and the L3 output time period.

[0290] When the decrease in the L3 output value is greater than the product of a given threshold "a" and the L3 output period, the UE sets the TTT to TTT1. If the Type 1 handover event condition meets the entry condition and remains so during TTT1, the UE can determine that a Type 1 handover event has occurred. If the Type 1 handover event condition does not meet the entry condition during TTT1, the UE can continuously perform the operation of comparing the decrease in two consecutive L3 output values ​​with the product of a given threshold "a" and the L3 output period. When the decrease in the L3 output value is less than the product of a given threshold "a" and the L3 output period, the UE sets the TTT to TTT2. The UE identifies whether the Type 1 handover event condition continues to meet the entry condition during TTT2. If the Type 1 handover event condition continues to meet the entry condition, the UE can execute the Type 1 handover event after TTT2 terminates. Figure 45 In one embodiment, the UE can identify the slope of a continuous signal strength change at a time when the Type 1 handover condition is met, and can selectively apply a Time Transition (TTI) based on the slope. If the Type 1 handover condition is not met during the selected TTI, the UE can initialize the TTI and return to the start step.

[0291] TTT1 can be set to a larger value than TTT2, resulting in an increased TTT value for Type 1 handover events when signal strength deteriorates suddenly. If the UE recognizes a Type 2 handover event when applying TTT to a Type 1 handover event, the UE will not perform a handover procedure based on the Type 1 handover event, but may perform a handover procedure based on the Type 2 handover event. In this case, Type 1 handover can mean network handover, and Type 2 handover can mean UE handover. The TTT values ​​(TTT1, TTT2) and slope value "a" to be applied to a Type 1 handover can be determined based on the priority assigned to the handover type. The TTT values ​​(TTT1, TTT2) and slope value "a" can be set based on eNB operation values ​​or provider operation values. The set TTT values ​​(TTT1, TTT2) and slope value "a" can be sent to the UE via UE-specific messages or using methods previously configured in the UE, such as system information broadcast messages, RRC configuration messages, or measurement configuration messages.

[0292] Figure 46 The determination of the continuous signal descent slope for network handover triggering of the UE is shown.

[0293] exist Figure 46 In this embodiment, the UE identifies whether the difference between the value before each L3 output time and the current value is greater than or less than the product of a given threshold "a" and the L3 output time period. When the difference between the previous value and the current value is greater than the product, the UE can set the Type 1 switching TTI to TTT1. When the difference between the previous L3 value and the current L3 value is less than the product of the given threshold "a" and the L3 output time period, the UE can set the Type 1 switching TTI to TTT2. The UE can use the continuous values ​​of the L3 output at each time to measure the slope. When the slope changes, the UE can set the Type 1 switching TTI to a new value (TTT1 or TTT2) based on the above conditions according to the changed timing. By setting the TTT value based on the slope, the switching process according to Type 1 switching and the switching process according to Type 2 switching can be executed.

[0294] In another embodiment, the UE can identify the slope value of the L3 output from the moment the entry condition for a Type 1 handover event is met to a given time interval. When the slope of the L3 output value is greater than a given threshold, the UE can set the TTT to TTT1. When the slope of the L3 output value is less than the given threshold, the UE can set the TTT to TTT2. That is, if the slope value is large or small for a given time, the UE does not identify the slope value of the remaining TTT duration, but can determine whether the Type 1 handover entry condition is met for the remaining TTT duration. If it is determined that the Type 1 handover entry condition is met for the remaining TTT duration, the UE can perform a Type 1 handover procedure after the TTT expires.

[0295] In this scenario, the given time can be set based on a time period or the number of two consecutive L3 output pairs, or it can be a value received from the eNB. For example, when two consecutive L3 output pairs are 1, the UE can identify whether the decrease in L3 output is greater than or less than the product of the threshold "a" and the L3 time period based on the first determination, and can determine whether the Type 1 handover event condition meets the entry condition. The UE can then perform... Figure 45 The operation.

[0296] If the Type 2 handover event condition is met during the TTT operation period, the UE will not perform a Type 1 handover operation and may perform a Type 2 handover operation. Type 1 and Type 2 handover events can use at least one of A1, A2, A3, A4, and A5 of the LTE system. Furthermore, TT1 and TTT2 can be set to eNB operation values ​​or provider operation values ​​and can be sent to the UE via UE-specific messages—such as system information broadcast messages, RRC configuration messages, or measurement configuration messages—or using methods previously configured in the UE.

[0297] It can be used Figure 45 and Figure 46 The UE performs a Type 1 handover using the operation described in the embodiment. The events and parameters for determining to perform a Type 2 handover can operate independently. For example, the UE can determine to perform a Type 2 handover during the operation of determining to perform a Type 1 handover, and can perform the handover process with the serving eNB and the target eNB based on the handover type at which the handover execution begins.

[0298] According to embodiments of this disclosure, the UE can apply Type 1 handover events and parameters to network handover, and can also apply Type 2 handover events and parameters to UE handover. The UE can apply UE handover events and parameters simultaneously with the network handover events and parameters. If UE handover is performed first, the UE can perform the process of using one of the candidate target cells to access the network and establishing an RRC connection through the corresponding target cell.

[0299] Alternatively, the UE can apply UE handover events and parameters simultaneously with network handover events and parameters. If network handover is performed first, the UE can perform the process of sending a measurement report to the current serving cell, accessing the target cell after receiving a handover command from the serving cell, and establishing an RRC connection through the corresponding target cell.

[0300] Figure 47 An example is shown where the serving eNB sends the measurement configuration to the UE and the UE performs a UE handover.

[0301] refer to Figure 47 The serving eNB sends a measurement configuration message to the UE (4710). The measurement configuration message provides parameters including events, slope values, and TTT (TTT1, TTT2) associated with type 1 handover (e.g., network handover (NW HO)) and parameters including events and TTT associated with type 2 handover (e.g., UE handover (UE HO)). TTT1 can be set to a TTT value that is longer than TTT2.

[0302] The UE that has already received the measurement configuration message can execute according to Figure 45 and Figure 46 The algorithm in this embodiment is used to identify the generation of a Type 1 handover event or a Type 2 handover event. When the magnitude of the decrease in measured signal strength is greater than the slope value by comparing the magnitude of the decrease in measured signal strength and the slope value (i.e., in the case of a sharp drop), the UE can apply a Time Limit to Time (TTT) as TTT1 (long TTT). The UE can monitor whether a Type 1 handover event occurs during TTT1. Furthermore, when TTT1 is in operation, the UE can apply a Time Limit to Time (TTI) to a Type 2 handover event. When a Type 2 handover event occurs during TTT, the UE can perform a Type 2 handover.

[0303] If a UE handover (Type 2 handover) event occurs at the same time as the UE monitors a network handover (Type 1 handover) event, the UE will not receive the serving cell's measurement report and handover command, and can directly execute the connection procedure with the target cell (4720).

[0304] exist Figure 47 In this embodiment, the type 1 switching related parameters may include events, slope values ​​for each event, TTT1 values ​​for each event, and TTT2 values ​​for each event. Figure 47 In another embodiment, the type 1 switching-related parameters may include events, slope values ​​for each event, TTT1 values, and TTT2 values. Figure 47 In another embodiment, the type 1 switching-related parameters may include an event, a slope value, a TTT1 value, and a TTT2 value.Figure 47 In another embodiment, type 2 switching-related parameters may include events and the TTT value for each event. Figure 47 In another embodiment, the type 2 switching-related parameters may include events and TTT values.

[0305] Figure 48 An example is shown where the serving eNB sends a measurement configuration to the UE and the UE performs a network handover.

[0306] refer to Figure 48 The serving eNB sends a measurement configuration message to the UE (4810). The measurement configuration message may include events and parameters for both Type 1 and Type 2 handover. In one embodiment, Type 1 handover may include network handover, and Type 2 handover may include UE handover. The measurement configuration may include network handover events, slope values, long TTT (TTT1) and short TTT (TTT2), and UE handover events and TTT.

[0307] UEs that have already received the measurement configuration message can apply Figure 45 and Figure 46 The algorithm states that if, by comparing the magnitude of the decrease in measured signal strength with the slope value, the magnitude of the decrease in measured signal strength is less than the slope value (i.e., in the case of a slow decrease), then the UE can apply TTT2 (short TTT) to the type 1 handover event.

[0308] If a Type 1 handover event has occurred but no Type 2 handover event has occurred by the time TTT2 expires, the UE performs a Type 1 handover. For example, the UE can determine that a network handover event has occurred and can send a Measurement Report (MR) to the serving eNB (4820). The serving cell and the target cell perform a handover preparation procedure (4830) together and send a handover command to the UE (4840). The UE can then perform a procedure to establish a connection to the target cell based on the handover command.

[0309] According to another embodiment, when a Type 1 handover event occurs and the UE therefore sends a measurement report to the serving eNB, the UE can drive a timer. When the UE receives a handover command from the serving cell while the timer is operating, the UE can perform a network handover based on the configuration information of the handover command. If no handover command is received from the serving cell before the timer expires, the UE can select one of the candidate target cells identified by measurement as the target cell and can establish a connection with the corresponding cell. The UE can obtain the radio interface configuration values ​​for attaching to the new target cell in advance through the handover preparation process. The UE can access the new target cell based on the previously obtained information and can perform additional radio resource configuration.

[0310] If the cell / eNB separates and installs the Central Unit (CU) and Distributed Unit (DU) functions, the CU can store resource configuration information for the UE. If the UE performs a handover between other DUs associated with the same CU, and if the UE does not receive a handover command after the measurement report until the timer expires, the UE can select a target DU cell and use the resources used in the serving DU cell while establishing a connection with the selected target DU cell.

[0311] The above description outlines a UE handover event configuration method for the serving eNB to notify the UE of multiple TTT values ​​for each slope during a handover operation. The following describes a method for performing network handover or UE handover, where the serving eNB configures slope values ​​and network handover events or serving eNB configuration information such as slope values, network handover events, and slope measurement time / sample count.

[0312] If the serving cell sends a slope value "a" to be applied to the network handover event via a measurement configuration message, and the network handover event meets the entry conditions during TTT, the UE compares the slope of the signal strength decrease with the value "a". When the slope of the signal strength decrease is greater than the value "a", the UE can perform a UE handover. When the slope of the signal strength decrease is less than the value "a", the UE can send a measurement report to the eNB and start a timer. When the UE receives a handover command from the serving cell before the timer expires, the UE can perform a network handover. If no handover command is received from the serving cell before the timer expires, the UE can perform a UE handover. If a UE handover is performed, the UE can select one of the candidate target cells determined based on the previously measured report as the target cell. The UE handover event may not be configured by the serving eNB. The serving eNB and the UE can pre-determine candidate target cells to prepare for the UE handover and can pre-execute measurement configurations for performing the handover and the corresponding measurement reports. The UE can be pre-configured with Random Access Channel (RACH) configuration, information about the beam used during access, information about RLC or PDCP configuration, and access information about candidate target cells, such as security key information in the target cell.

[0313] When a network handover event is triggered, the UE can perform a network handover or a UE handover based on the slope. The comparison between the slope and the threshold "a" can be performed in units of L3 output periods.

[0314] exist Figure 49 to Figure 52 In the embodiments described, it is assumed that Type 1 handover is network handover, and Type 2 handover is UE handover. However, different handover algorithms can be applied to either Type 1 or Type 2 handover.

[0315] Figure 49 An example is shown where the UE detects an event for handover and performs a handover when the identification signal decreases.

[0316] refer to Figure 49 The serving eNB can send measurement configuration information (4910) to the UE for discovering candidate target cells. The measurement configuration information may include events and parameters required for each handover type. For example, the serving eNB can send configuration information allowing the UE to use signal strength-based A1, A3, or A5 events for Type 1 handover. After the UE measures the signal strength of surrounding eNBs, the UE can discover eNBs / cells that meet the configuration events (4920). The UE can report the signal strength measurement results to the serving eNB (4930). The serving eNB can select candidate target eNBs based on the measurement results. The serving eNB can obtain the resources and configuration information required by the UE to perform handover and reconnection for the selected candidate target eNB (4940). The serving eNB can send the information required for handover and reconnection to the candidate target eNB (4950). Furthermore, the serving eNB can send event configuration information for performing Type 1 handover to the candidate target eNB. The event configuration information includes at least one of an event for slope comparison, a slope value "a", or an evaluation time T. Furthermore, the event configuration information may include parameters required for each event, whether reporting is periodic or per event, which TTT value will be used, and what type of event will be used. The UE can perform a Type 1 handover based on the event configuration information. When an event for Type 1 handover occurs during the TTT and the slope of the decrease in signal strength measured for a given T interval or a given number of samples is greater than the value "a" (4960), the UE can select one of the candidate target cells received in step 4950. Metrics for selecting a target cell can be pre-configured in the UE. For example, the UE can select a cell that is a candidate target cell and has the best signal strength. The UE can use the radio resource configuration information (4970) of the selected target cell to perform a connection establishment procedure (4980) with the target cell. For example, the UE can perform an RRC connection reconfiguration or RRC connection reconstruction procedure with the target cell.

[0317] At the same time, Figure 49 In the embodiments shown, although the transmission of event configuration information required for the measurement and execution of Type 1 handover is illustrated in each of steps 4910 and 4950, the event configuration information required for the measurement and execution of Type 1 handover may be transmitted together in either step 4910 or step 4950. Furthermore, the configuration information may include a list of candidate target cells configured by the serving eNB.

[0318] Figure 50 An example is shown where the UE detects an event for handover and performs a handover when there is no signal decline.

[0319] exist Figure 50 In this embodiment, the eNB and UE can perform the same operation. Figure 49 The operations from steps 4910 to 4950. That is, Figure 50 Steps 5010 to 5050 correspond to Figure 49 Steps 4910 to 4950. If a Type 1 handover event is triggered, the entry condition is met during the TTT, and the descent slope of the received signal is less than a given threshold "a" during a given evaluation time T (5060), the UE can send a measurement report used to trigger the event to the serving eNB (5070). The serving eNB can perform a handover preparation procedure with the target eNB based on the UE's measurement report. The serving eNB can determine the target eNB based on the handover preparation procedure and can send a handover command to the UE including information about the target eNB (5080). The UE can perform connection establishment with the target eNB based on the information included in the handover command (5090). The UE can use the radio resource configuration information included in the handover command.

[0320] At the same time, Figure 50 In the embodiments described, although the transmission of event configuration information required for the measurement and execution of Type 1 handover in each of steps 5010 and 5050 has been illustrated, the event configuration information required for the measurement and execution of Type 1 handover may be transmitted together in either step 5010 or step 5050. Furthermore, the configuration information may include a list of candidate target cells configured by the serving eNB.

[0321] Figure 51 An example of the UE's operation is shown when the UE receives a handover command in a method for the UE to detect a handover event using a timer and perform a handover.

[0322] exist Figure 51 In this embodiment, the eNB and UE can perform the same operation. Figure 49 The operations from steps 4910 to 4950. That is, Figure 51 Steps 5110 to 5150 correspond to Figure 49Steps 4910 to 4950. If a network handover event is triggered, the entry condition is met during the TTT, and the descent slope of the received signal is less than a given threshold "a" (5160) during a given evaluation time T, the UE may send a measurement report (5170) to the serving eNB to trigger the event. The UE may start a timer for the measurement report from the timing of sending the measurement report (5180). The serving eNB may perform a handover preparation procedure with the target eNB based on the UE's measurement report. The serving eNB may determine the target eNB based on the handover preparation procedure and may send a handover command (5190) to the UE including information about the target eNB. When the handover command is received from the serving eNB before the timer for the measurement report expires, the UE may perform connection establishment with the target eNB based on the information included in the handover command (5200). The UE may use the radio resource configuration information included in the handover command.

[0323] At the same time, Figure 51 In the embodiments described, although the transmission of event configuration information required for the measurement and execution of Type 1 handover in each of steps 5110 and 5150 has been illustrated, the event configuration information required for the measurement and execution of Type 1 handover may be transmitted together in either step 5110 or step 5150. Furthermore, the configuration information may include a list of candidate target cells configured by the serving eNB.

[0324] Figure 52 An example of the UE's operation is shown when the UE does not receive a handover command in a method for the UE to detect handover events using a timer and perform a handover.

[0325] exist Figure 52 In this embodiment, the eNB and UE can perform the same operation. Figure 51 The operations from steps 5110 to 5180. That is, Figure 52 Steps 5210 to 5280 and Figure 51 Steps 5110 to 5180 are the same. If no handover command is received from the serving eNB before the timer for the measurement report driven in step 5280 expires, the UE can select one of the candidate target eNBs (5290). As an example of a metric used to select one of the candidate target eNBs, the UE can select the cell that belongs to the candidate target cell and has the best signal strength. The UE can use the previously obtained radio resource configuration information about the target eNB to perform connection establishment with the selected target eNB (5300).

[0326] At the same time, Figure 52In the embodiments described, although the transmission of event configuration information required for the measurement and execution of Type 1 handover in each of steps 5210 and 5250 has been illustrated, the event configuration information required for the measurement and execution of Type 1 handover may be transmitted together in either step 5210 or step 5250. Furthermore, the configuration information may include a list of candidate target cells configured by the serving eNB.

[0327] Additionally, separate events can be defined for UE handover. For example, the eNB can configure the following UE handover event configuration factors.

[0328] S1: When the rate of decline of the serving cell (beam) during TTT is “a” or greater (parameter: a, TTT).

[0329] S2: When the rate of decrease of neighboring cells (beams) during TTT is “a” or greater (parameters: a, TTT).

[0330] S3: When the descent rate of the serving cell (beam) during TTT is “a” or greater and the descent rate of the neighboring cell (beam) during TTT is “b” or greater (parameters: a, b, TTT).

[0331] The serving eNB can configure events for UE handover. For example, an entry condition could be: signal value (L3 output) in serving cell t0 - signal value (L3 output) in serving cell t1 > threshold "a" × L3 output time period. If the entry condition is met during the TTT (Time To Time), the UE can perform a UE handover. If the entry condition for a UE handover event is met, the UE can postpone the application of the network handover event until the TTI used for the UE handover event expires.

[0332] Figure 53 This is a diagram illustrating a UE according to an embodiment of the present disclosure.

[0333] refer to Figure 53 UE 5300 may include a transceiver 5310 and a controller 5330. Controller 5330 may include at least one processor. Transceiver 5310 and controller 5330 may be electrically connected. Controller 5330 may control transceiver 5310 to send and receive signals. Controller 5330 sending and / or receiving signals, information, messages, etc. may be interpreted as controller 5330 controlling transceiver 5310 to send and / or receive signals, information, messages, etc.

[0334] UE 5300 can transmit and / or receive signals via transceiver 5310. Controller 5330 can control the overall operation of UE 5300. Furthermore, controller 5330 can control signals transmitted via... Figure 1 to Figure 52 The described UE operation.

[0335] Figure 54 This is a diagram illustrating an eNB according to an embodiment of the present disclosure.

[0336] refer to Figure 54 The eNB 5400 may include a transceiver 5410 and a controller 5430. The controller 5430 may include at least one processor. The transceiver 5410 and the controller 5430 may be electrically connected. The controller 5430 can control the transceiver 5410 to send and receive signals. The content of signals, information, messages, etc., sent and / or received by the controller 5430 can be interpreted as indicating that the controller 5430 controls the transceiver 5410 to send and / or receive signals, information, messages, etc.

[0337] Base station 5400 can transmit and / or receive signals via transceiver 5410. Controller 5430 can control the overall operation of base station 5400. Furthermore, controller 5430 can control the transmission of signals via... Figure 1 to Figure 52 The description of eNB operations.

[0338] Furthermore, the embodiments disclosed in the specification and accompanying drawings are merely specific examples provided to facilitate the description and understanding of this disclosure, and are not intended to limit the scope of this disclosure. Therefore, in addition to the disclosed embodiments, the scope of this disclosure should be interpreted to include all changes or modifications derived from the technical spirit of this disclosure.

Claims

1. A method performed by a terminal in a wireless communication system, the method comprising: The radio resource control (RRC) message is received from the first base station. The RRC message includes at least one packet data convergence protocol (PDCP) configuration information, and the PDCP configuration information includes PDCP replication information. Generate the first PDCP protocol data unit (PDU) and submit the first PDCP PDU to the main radio link control (RLC) entity; Generate a second PDCP PDU and submit the second PDCP PDU to the auxiliary RLC entity, wherein the second PDCP PDU is a copy of the first PDCPPDU; The first Media Access Control (MAC) control element CE receives the first Media Access Control (MAC) control element CE from the first base station to deactivate the data radio bearer DRB configured with PDCP replication; Based on the first MAC CE that deactivates PDCP replication, the second PDCP PDU is discarded in the secondary RLC entity; as well as Send the first PDCP PDU to the first base station.

2. The method according to claim 1, in, At least one PDCP configuration information corresponds to each DRB, and The PDCP replication information indicates whether the corresponding DRB is configured for PDCP replication.

3. The method according to claim 1, wherein, The generation of the first PDCP PDU and the generation of the second PDCP PDU include: Receive a second MAC CE from the first base station that activates the DRB configured with PDCP replication; and The first PDCP PDU and the second PDCP PDU are generated based on the second MAC CE that activates PDCP replication.

4. The method according to claim 3, further comprising: The third and fourth PDCP PDUs of DRB are generated based on the second MAC CE, wherein the fourth PDCP PDU is a copy of the third PDCP PDU; Based on the second MAC CE, submit the third PDCP PDU to the primary RLC entity and submit the fourth PDCP PDU to the secondary RLC entity; as well as Before receiving the first MAC CE, a third PDCP PDU is sent to the first base station, and a fourth PDCPPDU is sent to the second base station.

5. The method according to claim 1, wherein, The first MAC CE also includes: Receive the first MAC CE from the first base station to deactivate PDCP replication; Generate the fifth PDCP PDU of the DRB, wherein the first MAC CE based on deactivating PDCP replication does not generate a PDCP PDU as a replica of the fifth PDCP PDU; and Submit the fifth PDCP PDU to the main RLC entity.

6. A terminal in a wireless communication system, the terminal comprising: A transceiver is configured to send and receive signals; as well as The controller, coupled to the transceiver, is configured as follows: A Radio Resource Control (RRC) message is received from the first base station. This RRC message includes at least one Packet Data Convergence Protocol (PDCP) configuration information, which contains PDCP replication information. Generate the first PDCP Protocol Data Unit (PDU) and submit the first PDCP PDU to the Master Radio Link Control (RLC) entity. Generate a second PDCP PDU and submit the second PDCP PDU to the secondary RLC entity, wherein the second PDCP PDU is a copy of the first PDCP PDU. The first Media Access Control (MAC) control element CE receives the first PDCP copy of the data radio bearer DRB configured with PDCP copy from the first base station to deactivate the PDCP copy. Based on the first MAC CE of deactivating PDCP replication, the second PDCP PDU is discarded in the secondary RLC entity, and Send the first PDCP PDU to the first base station.

7. The terminal according to claim 6, in, At least one PDCP configuration information corresponds to each DRB, and The PDCP replication information indicates whether the corresponding DRB is configured for PDCP replication.

8. The terminal according to claim 6, wherein, The controller is also configured as follows: Receive a second MAC CE from the first base station that activates the DRB configured with PDCP replication; and The first PDCP PDU and the second PDCP PDU are generated based on the second MAC CE that activates PDCP replication.

9. The terminal according to claim 8, wherein, The controller is also configured as follows: The third and fourth PDCP PDUs of DRB are generated based on the second MAC CE that activates PDCP replication, wherein the fourth PDCP PDU is a copy of the third PDCP PDU; Based on the second MAC CE, submit the third PDCP PDU to the primary RLC entity and submit the fourth PDCP PDU to the secondary RLC entity; as well as Before receiving the first MAC CE, a third PDCP PDU is sent to the first base station, and a fourth PDCPPDU is sent to the second base station.

10. The terminal according to claim 6, wherein, The controller is also configured as follows: Receive the first MAC CE from the first base station to deactivate PDCP replication; Generate the fifth PDCP PDU of DRB, wherein the first MAC CE based on deactivating PDCP replication does not generate a PDCP PDU as a replication of the fifth PDCP PDU; as well as Submit the fifth PDCP PDU to the main RLC entity.

11. A method performed by a first base station in a wireless communication system, the method comprising: Send a Radio Resource Control (RRC) message to the terminal. The RRC message includes at least one Packet Data Convergence Protocol (PDCP) configuration information, which contains PDCP replication information. Send the first Media Access Control (MAC) control element (CE) of the data radio bearer DRB configured with PDCP replication to the terminal to deactivate PDCP replication; as well as The terminal receives the first PDCP protocol data unit (PDU) from the terminal via the main radio link control RLC entity. The first PDCP PDU is generated and submitted to the main RLC entity. In this process, a second PDCP PDU is generated and submitted to the secondary RLC entity. The second PDCP PDU is a copy of the first PDCP PDU. In this process, the first MAC CE based on deactivating PDCP replication is used, and the second PDCP PDU is discarded in the auxiliary RLC entity.

12. The method according to claim 11, in, At least one PDCP configuration information corresponds to each DRB, and The PDCP replication information indicates whether the corresponding DRB is configured for PDCP replication.

13. The method of claim 11, further comprising: Send a second MAC CE to the terminal to activate the PDCP replication of the DRB configured with PDCP replication. Specifically, based on the second MAC CE that activates PDCP replication, the first PDCP PDU and the second PDCP PDU are generated.

14. The method of claim 13, further comprising: Receives a third PDCP PDU from the terminal via the terminal's primary RLC entity. Specifically, based on the second MAC CE, the third and fourth PDCP PDUs of the DRB are generated, wherein the fourth PDCP PDU is a copy of the third PDCP PDU. Specifically, based on the second MAC CE, the third PDCP PDU was submitted to the primary RLC entity, and the fourth PDCP PDU was submitted to the secondary RLC entity. The fourth PDCP PDU is sent to the second base station via the terminal's auxiliary RLC entity.

15. The method of claim 11, further comprising: The fifth PDCP PDU is received from the terminal via the terminal's main RLC entity. In this process, the fifth PDCP PDU of the DRB is generated, wherein the first MAC CE based on deactivating PDCP replication does not generate a PDCP PDU as a copy of the fifth PDCP PDU, and Among them, the fifth PDCP PDU was submitted to the main RLC entity.

16. A first base station in a wireless communication system, the first base station comprising: A transceiver is configured to send and receive signals; as well as The controller, coupled to the transceiver, is configured as follows: A Radio Resource Control (RRC) message is sent to the terminal. This RRC message includes at least one Packet Data Convergence Protocol (PDCP) configuration information, which contains PDCP replication information. Sending the first Media Access Control (MAC) control element (CE) to the terminal to deactivate the data radio bearer DRB configured for PDCP replication, and... The terminal receives the first PDCP protocol data unit (PDU) from the terminal via the main radio link control RLC entity. The first PDCP PDU is generated and submitted to the main RLC entity. In this process, a second PDCP PDU is generated and submitted to the secondary RLC entity. The second PDCP PDU is a copy of the first PDCP PDU. In this process, the first MAC CE based on deactivating PDCP replication is used, and the second PDCP PDU is discarded in the auxiliary RLC entity.

17. The first base station according to claim 16, in, At least one PDCP configuration information corresponds to each DRB, and The PDCP replication information indicates whether the corresponding DRB is configured for PDCP replication.

18. The first base station according to claim 16, in, The controller is also configured as follows: Send a second MAC CE to the terminal to activate the PDCP replication of the DRB configured with PDCP replication, and Specifically, based on the second MAC CE that activates PDCP replication, the first PDCP PDU and the second PDCP PDU are generated.

19. The first base station according to claim 18, in, The controller is also configured as follows: Receives a third PDCP PDU from the terminal via the terminal's primary RLC entity. Specifically, based on the second MAC CE, the third and fourth PDCP PDUs of the DRB are generated, wherein the fourth PDCP PDU is a copy of the third PDCP PDU. Specifically, based on the second MAC CE, the third PDCP PDU was submitted to the primary RLC entity, and the fourth PDCP PDU was submitted to the secondary RLC entity. The fourth PDCP PDU is sent to the second base station via the terminal's auxiliary RLC entity.

20. The first base station according to claim 16, wherein, The controller is also configured as follows: The fifth PDCP PDU is received from the terminal via the terminal's main RLC entity. In this process, the fifth PDCP PDU of the DRB is generated, wherein the first MAC CE based on deactivating PDCP replication does not generate a PDCP PDU as a copy of the fifth PDCP PDU, and Among them, the fifth PDCP PDU was submitted to the main RLC entity.

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