Method and apparatus for controlling activation of multiple radio link control layer devices in wireless communication system

Abstract

A user equipment (UE) in a wireless communication system and a method performed by the same are provided. The method comprises the following steps: receiving a first message for configuring packet data convergence protocol (PDCP) repetition of a radio bearer from a base station (BS); repeatedly configuring a primary radio link control (RLC) entity and one or more secondary RLC entities for the PDCP; and receiving, from the BS, a second message related to deactivation of the PDCP repetition; identifying whether a separate secondary RLC entity is configured in the one or more secondary RLC entities in the event of deactivating PDCP repetition for the radio bearer; and transmitting a PDCP protocol data unit (PDU) based on the primary RLC entity or the separate secondary RLC entity in a case where the separate secondary RLC entity is configured.

Description

[0001] This application is a divisional application of an application with a filing date of March 25, 2020 and application number 202080020309.0, whose invention name is “Method and apparatus for controlling activation of multiple radio link control layer devices in a wireless communication system”. Technical Field

[0002] The present disclosure relates to a method and apparatus for controlling activation of a plurality of Radio Link Control (RLC) layers in a wireless communication system. Background Art

[0003] After the commercialization of the fourth generation (4G) communication system, in order to meet the growing demand for wireless data services, efforts have been made to develop an evolved fifth generation (5G) system or a pre-5G communication system. For this reason, the 5G or pre-5G communication system is called a "super 4G network" communication system or a "post-long term evolution (post-LTE)" system. The 5G communication system defined in the Third Generation Partnership Project Long Term Evolution (3GPP LTE) is called a new radio (NR) system. In order to achieve high data rates, the implementation of the 5G communication system in an ultra-high frequency or millimeter wave (mmWave) band (e.g., a 60 GHz band) is being considered. In order to reduce the path loss of radio waves in the ultra-high frequency band used for the 5G communication system and increase the transmission distance of the radio waves, various technologies, such as beamforming, massive multiple input multiple output (massive MIMO), full-dimensional multiple input multiple output (FD-MIMO), array antennas, analog beamforming, and massive antennas are being studied and applied to NR systems. In order to improve the system network for 5G communication system, various technologies have been developed, such as evolved small cells, advanced small cells, cloud radio access networks (cloud-RAN), ultra-dense networks, device-to-device communication (D2D), wireless backhaul, mobile networks, cooperative communication, coordinated multi-point (CoMP), interference cancellation, etc. In addition, for 5G communication systems, advanced coding modulation (ACM) technologies such as hybrid frequency shift keying (FSK) and quadrature amplitude modulation (QAM) (FQAM) and sliding window superposition coding (SWSC) have been developed, and advanced access technologies such as filter bank multi-carrier (FBMC), non-orthogonal multiple access (NOMA), sparse code multiple access (SCMA), etc. have been developed.

[0004] The Internet has evolved from a human-based connected network where humans create and consume information to the Internet of Things (IoT), in which distributed elements such as objects exchange information with each other to process information. Internet of Everything (IoE) technology has emerged, in which IoT technology is combined with technology for processing big data, such as by connecting with cloud servers. In order to realize IoT, various technical elements such as sensing technology, wired / wireless communication and network infrastructure, service interface technology, and security technology are required, so that in recent years, technologies related to sensor networks for connecting objects, machine-to-machine (M2M) communication, and machine-type communication (MTC) have been studied. In the IoT environment, smart Internet technology (IT) services can be provided to collect and analyze data obtained from connected objects, thereby creating new value in human life. With the integration and mutual combination of existing information technology (IT) and various industries, IoT may be applied to various fields such as smart homes, smart buildings, smart cities, smart cars or connected cars, smart grids, healthcare, smart appliances, and advanced medical services.

[0005] Various attempts are being made to apply 5G communication systems to IoT networks. For example, 5G communications such as sensor networks, M2M communications, MTC, etc. are implemented by using technologies including beamforming, MIMO, array antennas, etc. Cloud-RAN as an application of the above big data processing technology may be an example of the fusion of 5G communication technology and IoT technology.

[0006] Due to the development of wireless communication systems, there is a need for a method of controlling activation of multiple Radio Link Control (RLC) layers in a system supporting high reliability and low delay services. Summary of the invention

[0007] Technical issues

[0008] Embodiments disclosed herein provide a method and apparatus for controlling activation of multiple radio link control (RLC) layers in a wireless communication system.

[0009] Solution to the problem

[0010] Embodiments disclosed herein may provide a method and apparatus for controlling activation of multiple radio link control (RLC) layers in a wireless communication system.

[0011] According to an embodiment of the present disclosure, a method performed by a user equipment (UE) includes: receiving a first message for configuring a packet data convergence protocol (PDCP) repetition of a wireless bearer from a base station (BS); configuring a primary radio link control (RLC) entity and one or more secondary RLC entities for PDCP repetition; and receiving a second message related to deactivation of PDCP repetition from the BS; in the case of deactivating PDCP repetition for the wireless bearer, identifying whether a separated secondary RLC entity is configured in one or more secondary RLC entities; and in the case of a separated secondary RLC entity being configured, sending a PDCP protocol data unit (PDU) based on the primary RLC entity or the separated secondary RLC entity.

[0012] According to an embodiment of the present disclosure, a user equipment UE in a wireless communication system is provided, the UE comprising: a transceiver and a controller. The controller is configured to: receive a first message for configuring a packet data convergence protocol (PDCP) repetition of a radio bearer from a base station (BS) via the transceiver, configure a primary radio link control (RLC) entity and one or more secondary RLC entities for PDCP repetition, and receive a second message related to deactivation of PDCP repetition from the BS via the transceiver, in the case of deactivating PDCP repetition for a radio bearer, identify whether a separated secondary RLC entity is configured in one or more secondary RLC entities, and in the case of a separated secondary RLC entity being configured, send a PDCP protocol data unit (PDU) based on the primary RLC entity or the separated secondary RLC entity.

[0013] According to an embodiment of the present disclosure, a method performed by a base station (BS) includes: sending a first message to a user equipment (UE) to configure a packet data convergence protocol (PDCP) repetition of a wireless bearer, wherein the first message is associated with a primary radio link control (RLC) entity and configures one or more secondary RLC entities for the PDCP repetition in the UE; sending a second message related to deactivation of the PDCP repetition to the UE; and, in a case where the PDCP repetition is deactivated for the wireless bearer and a separated secondary RLC entity is configured in one or more secondary RLC entities, receiving a PDCP protocol data unit (PDU) sent from the UE based on the primary RLC entity or the separated secondary RLC entity.

[0014] According to an embodiment of the present disclosure, a base station BS in a wireless communication system is provided. The BS includes a transceiver and a controller. The controller is configured to: send a first message for configuring a packet data convergence protocol (PDCP) repetition of a radio bearer to a user equipment (UE) via the transceiver, wherein the first message is associated with a primary radio link control (RLC) entity and configures one or more secondary RLC entities for PDCP repetition in the UE, send a second message related to deactivation of PDCP repetition to the UE via the transceiver, and receive a PDCP protocol data unit (PDU) sent based on the primary RLC entity or the separated secondary RLC entity from the UE via the transceiver when PDCP repetition is deactivated for the radio bearer and a separated secondary RLC entity is configured in one or more secondary RLC entities.

[0015] The beneficial effects of disclosure

[0016] According to the embodiments disclosed herein, activation of multiple radio link control (RLC) layers of a user equipment (UE) in a wireless communication system may be effectively controlled. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1A is a diagram showing a configuration of a Long Term Evolution (LTE) system according to an embodiment of the present disclosure.

[0018] Figure 1B is a diagram showing a radio protocol architecture of an LTE system according to an embodiment of the present disclosure.

[0019] Figure 1C is a diagram illustrating a next generation mobile communication system according to an embodiment of the present disclosure.

[0020] Figure 1D is a diagram showing a radio protocol architecture of a next generation mobile communication system according to an embodiment of the present disclosure.

[0021] Figure 1E It is a diagram for describing the process of a user equipment (UE) transitioning from a radio resource control (RRC) idle mode or an RRC inactive mode to an RRC connected mode, and a base station (BS) configuring a carrier aggregation (CA) technology, a dual connectivity (DC) technology, or a packet repetition technology for the UE according to an embodiment of the present disclosure.

[0022] Figure 1F A protocol entity configured with a packet repetition technique according to an embodiment of the present disclosure is shown.

[0023] Figure 1G A protocol entity configured with a packet repetition technique according to an embodiment of the present disclosure is shown.

[0024] Figure 1HA protocol entity configured with a packet repetition technique according to an embodiment of the present disclosure is shown.

[0025] Fig. 1I Embodiment 1 according to an embodiment of the present disclosure is shown, wherein when multiple radio link control (RLC) entities are configured for a UE configured with a packet repetition transmission technology, some of the multiple configured RLC entities are dynamically activated or deactivated.

[0026] Figure 1J Embodiment 2 according to an embodiment of the present disclosure is shown, in which when multiple RLC entities are configured for a UE configured with a packet repetition transmission technology, some of the multiple configured RLC entities are dynamically activated or deactivated.

[0027] Figure 1K Embodiment 3 according to an embodiment of the present disclosure is shown, in which when multiple RLC entities are configured for a UE configured with a packet repetition transmission technology, some of the multiple configured RLC entities are dynamically activated or deactivated.

[0028] Figure 1L Embodiment 4 according to an embodiment of the present disclosure is shown, in which when multiple RLC entities are configured for a UE configured with a packet repetition transmission technology, some of the multiple configured RLC entities are dynamically activated or deactivated.

[0029] Figure 1M Embodiment 5 according to an embodiment of the present disclosure is shown, in which when multiple RLC entities are configured for a UE configured with a packet repetition transmission technology, some of the multiple configured RLC entities are dynamically activated or deactivated.

[0030] Figure 1N Embodiment 6 according to an embodiment of the present disclosure is shown, in which when multiple RLC entities (or logical channel identifiers) are configured for a UE configured with a packet repetition transmission technology, some of the multiple configured RLC entities are dynamically activated or deactivated.

[0031] Fig.1O Embodiment 7 according to an embodiment of the present disclosure is shown, wherein when multiple RLC entities (or logical channel identifiers) are configured for a UE configured with a packet repetition transmission technology, some of the multiple configured RLC entities are dynamically activated or deactivated.

[0032] Figure 1P Embodiment 8 according to an embodiment of the present disclosure is shown, wherein when multiple RLC entities are configured for a UE configured with a packet repetition transmission technique, all the multiple configured RLC entities are dynamically activated or deactivated.

[0033] Figure 1QThe UE operation proposed in the embodiments of the present disclosure is shown.

[0034] Figure 1R is a block diagram of a configuration of a UE according to an embodiment of the present disclosure.

[0035] Figure 1S is a block diagram of a transmission / reception point (TRP) device in a wireless communication system according to an embodiment of the present disclosure.

[0036] Figure 1T Embodiment 9 according to an embodiment of the present disclosure is shown, in which when multiple RLC entities (or logical channel identifiers) are configured for a UE configured with a packet repetition transmission technology, some of the multiple configured RLC entities are dynamically activated or deactivated. DETAILED DESCRIPTION

[0037] According to an embodiment of the present disclosure, a method for performing communication in a wireless communication system by using multiple radio link control (RLC) entities, performed by a user equipment (UE), includes: receiving a packet repetition configuration of a wireless bearer from a base station (BS) via a radio resource control (RRC) message; configuring multiple RLC entities based on the packet repetition configuration, the multiple RLC entities including a primary RLC entity and one or more secondary RLC entities corresponding to a preset packet data convergence protocol (PDCP) entity; and receiving a media access control control element (MAC CE) for controlling activation or deactivation of one or more secondary RLC entities from the multiple configured RLC entities.

[0038] The MAC CE may include a bearer identifier field for application packet repetition configuration and one or more RLC fields corresponding to one or more secondary RLC entities.

[0039] The MAC CE may have a fixed size, and may be identified by a logical channel identifier of a MAC CE for controlling activation or deactivation of the one or more secondary RLC entities.

[0040] The one or more RLC fields may be respectively mapped to the one or more secondary RLC entities, and the one or more RLC fields may include information for controlling activation or deactivation of the one or more secondary RLC entities respectively corresponding to the one or more RLC fields.

[0041] The one or more RLC fields may be sorted in ascending order based on logical channel identifiers of one or more secondary RLC entities corresponding to the one or more RLC fields, respectively.

[0042] Receiving the MAC CE may include receiving a MAC CE indicating deactivation of all of the one or more secondary RLC entities, and the method further includes deactivating a packet repetition configuration.

[0043] The method may further include operating in a split bearer mode for transmitting different data by using a primary RLC entity of the radio bearer and a preset secondary RLC entity among the one or more secondary RLC entities.

[0044] According to an embodiment of the present disclosure, a method for controlling the activation of multiple radio link control (RLC) entities configured for a user equipment (UE) in a wireless communication system, performed by a base station (BS), includes: sending a packet repetition configuration of a radio bearer via a radio resource control (RRC) message; and sending a media access control control element (MAC CE) for controlling the activation or deactivation of one or more secondary RLC entities among the multiple RLC entities, the multiple entities including a primary RLC entity and one or more secondary RLC entities corresponding to a preset packet data convergence protocol (PDCP) entity configured for the UE.

[0045] The MAC CE may include an identifier field regarding a radio bearer for which packet repetition configuration is configured, and one or more RLC fields corresponding to the one or more secondary RLC entities.

[0046] The MAC CE may have a fixed size, and may be identified due to a logical channel identifier indicating that the MAC CE is a MAC CE for controlling activation or deactivation of the one or more secondary RLC entities.

[0047] The one or more RLC fields may be respectively mapped to the one or more secondary RLC entities, and the one or more RLC fields may include information for controlling activation or deactivation of the one or more secondary RLC entities respectively corresponding to the one or more RLC fields.

[0048] The one or more RLC fields may be sorted in ascending order based on logical channel identifiers of the one or more secondary RLC entities respectively corresponding to the one or more RLC fields.

[0049] The sending of the MAC CE may include indicating deactivation of the packet repetition configuration by indicating deactivation of all one or more secondary RLC entities of the UE.

[0050] According to an embodiment of the present disclosure, a user equipment (UE) for performing communication by using multiple radio link control (RLC) entities in a wireless communication system includes a transceiver and a processor. The processor is combined with the transceiver and is configured to receive a packet repetition configuration of a radio bearer from a base station (BS) via a radio resource control (RRC) message; based on the packet repetition configuration, configure multiple RLC entities, the multiple RLC entities including a primary RLC entity and one or more secondary RLC entities corresponding to a preset packet data convergence protocol (PDCP) entity; and receive a media access control control element (MAC CE) for controlling activation or deactivation of one or more secondary RLC entities from multiple configured RLC entities.

[0051] According to an embodiment of the present disclosure, a base station (BS) for controlling activation of multiple radio link control (RLC) entities configured for a user equipment (UE) in a wireless communication system includes a transceiver and a processor. The processor is combined with the transceiver and is configured to send a packet repetition configuration of a radio bearer via a radio resource control (RRC) message; and send a media access control control element (MAC CE) for controlling activation or deactivation of one or more secondary RLC entities in a plurality of RLC entities, wherein the plurality of entities include a primary RLC entity and one or more secondary RLC entities corresponding to a preset packet data convergence protocol (PDCP) entity configured for the UE.

[0052] Public Mode

[0053] Embodiments of the present disclosure will now be described more fully with reference to the accompanying drawings. In the following description of the embodiments, descriptions of technologies that are well known in the art and not directly related to the present disclosure are omitted. This is to clearly convey the main points of the present disclosure by omitting unnecessary explanations.

[0054] For the same reason, some elements in the accompanying drawings are exaggerated, omitted or schematically shown. In addition, the size of each element does not fully reflect the actual size. In the accompanying drawings, the same or corresponding elements are represented by the same reference numerals.

[0055] The advantages and features of the present disclosure and methods of achieving them will become apparent with reference to the embodiments described in detail below with reference to the accompanying drawings. However, the present disclosure may be implemented in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments of the present disclosure are provided to make the present disclosure thorough and complete and to fully convey the scope of the present disclosure, which is limited only by the claims, to those of ordinary skill in the art. Throughout the specification, the same elements are represented by the same reference numerals.

[0056] It should be understood that each block of the flowchart description and the combination of blocks in the flowchart description can be implemented by computer program instructions. The computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, or other programmable data processing device, so that the instructions executed by the processor of the computer or other programmable data processing device generate a device for performing the functions specified in the flowchart block. The computer program instructions can also be stored in a computer-usable or computer-readable memory, which can guide 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 including an instruction device, which performs the functions specified in the flowchart box. The computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are performed on the computer or other programmable device, thereby generating a computer-implemented process, so that the instructions executed on the computer or other programmable device provide steps for implementing the functions specified in the flowchart block.

[0057] In addition, each block of the flowchart diagram may represent a module, segment or portion of code, which includes one or more executable instructions for performing a specified logical function. It should also be noted that in some alternative implementations, the functions mentioned in the blocks may not occur in order. For example, depending on the functions involved, two blocks shown in succession may actually be executed substantially simultaneously, or the blocks may sometimes be executed in reverse order.

[0058] The term "unit" used in the current embodiment of the present disclosure refers to a software or hardware component that performs a specific task, such as a field programmable gate array (FPGA) or an application specific integrated circuit (ASIC). However, the term "unit" is not meant to be limited to software or hardware. A "unit" can be configured in an addressable storage medium, or configured to operate one or more processors. Therefore, for example, a "unit" can include components, such as software components, object-oriented software components, class components and task components, processes, functions, attributes, procedures, subroutines, program code segments, drivers, firmware, microcodes, circuits, data, databases, data structures, tables, arrays and variables. The functions provided in components and "units" can be combined into fewer components and "units", or can be further divided into additional components and "units". In addition, components and "units" can be implemented as one or more central processing units (CPUs) in an operating device or a secure multimedia card. Similarly, in an embodiment of the present disclosure, a "unit" can include one or more processors.

[0059] Hereinafter, for the convenience of explanation, terms identifying access nodes, terms indicating network entities, terms indicating messages, terms indicating interfaces between network entities, and terms indicating various identification information used in the following description are exemplified. Therefore, the present disclosure is not limited to the terms to be described below, and other terms indicating objects having the same technical meaning may be used.

[0060] For convenience of description, the present disclosure uses the terms and names defined in the 3rd Generation Partnership Project (3GPP) Long Term Evolution (LTE) standard. However, the present disclosure is not limited to these terms and names, and can be applied to communication systems that comply with other standards in the same manner. In the present disclosure, for ease of explanation, evolved Node B (eNB) can be used interchangeably with next-generation Node B (gNB). That is, the base station (BS) described by eNB can represent gNB. In the present disclosure, the term "user equipment (UE)" can represent not only mobile phones, narrowband Internet of Things devices (NB-IoT) and sensors, but also various wireless communication devices.

[0061] In order to support services with high data rates and low transmission delays in next-generation mobile communication systems, it is necessary for the BS to quickly configure carrier aggregation (CA) technology or dual connection (DC) technology for the UE. In addition, in order to support services with higher reliability and lower transmission delays (for example, Industrial IoT (IIoT)), a packet repetition technology can be configured and used, or the CA technology and the DC technology can be configured and used together with the packet repetition technology. In addition, it may be necessary to provide a method that extends the principle of additionally sending two or more repetition data about one data to improve the reliability in the packet repetition technology by additionally sending one repetition data about one data. In addition, it may be necessary to provide dynamically controllable signaling so as to dynamically send zero, one, two, or three repetition data when needed.

[0062] In the present disclosure, a method is provided, which extends the principle that one repeated data about one data is additionally sent to additionally send three repeated data about one data to improve the reliability in the packet repetition technology. In addition, a dynamically controllable signaling is provided for dynamically sending zero, one, two or three repeated data instead of one or three repeated data when needed.

[0063] Therefore, in the present disclosure, a UE configured with a CA technology, a DC technology, or a packet repetition technology is being considered, and the following terms are used to implement the provided method.

[0064] -Primary cell (Pcell): Pcell refers to the serving cell used when the UE first configures a connection with the BS, and the UE configures the connection by sending or receiving some or all radio resource control (RRC) messages using the PCell. In addition, since the PCell always has physical uplink control channel (PUCCH) transmission resources, it can indicate a hybrid automatic repeat request (HARQ) acknowledgment (ACK) or negative acknowledgment (NACK), can always be configured with uplink (UL) and downlink (DL), and can be used as a reference cell for timing advance, i.e., the primary timing advance group (pTAG). For example, after the PCell is configured, in the case where the CA technology is configured and the SCell is thus added, the SCell can perform UL data transmission by referring to the timing advance value of the PCell. In the case where the DC technology is configured, the PCell refers to the PCell of the primary cell group (MCG).

[0065] -Master Cell Group (MCG): MCG refers to a serving cell or a group of cells supported by a BS, i.e., a serving cell used when the UE first configures a connection with the BS, and some or all RRC messages can be sent or received through the MCG when the DC technology is configured.

[0066] - Secondary Cell Group (SCG): When a UE configures a connection with a BS and then adds a cell of another BS other than MCG, SCG refers to a group of cells supported by another BS. In the case where DC technology is configured, SCG can be added to additionally increase the data rate or effectively support the mobility of the UE.

[0067] -Primary Secondary Cell (PScell): In the case where the UE configures a connection with a BS and then configures DC technology to add a group of cells of another BS, the cell corresponding to the PCcell in the SCG is called a PScell.

[0068] -Secondary Cell (SCell): After the UE configures a connection with the BS for the first time, the BS additionally configures a cell to configure the CA technology. In this regard, each cell is called an SCell. The SCell may have PUCCH transmission resources configured according to the base station configuration, the SCell may be configured with UL or DL ​​configured according to the base station configuration, or the SCell may be used as a reference cell for the timing advance, the secondary timing advance group (sTAG) according to the base station configuration. For example, after the PCell is configured, the CA technology is configured and the SCell is added and the sTAG is configured, other SCells of the sTAG can perform UL data transmission by referring to the timing advance value of the specified SCell. In the case of configuring the DC technology for the UE, the SCell refers to the SCell of the MCG that does not include the PCell or the SCell of the SCG that does not include the PScell.

[0069] - Primary Radio Link Control (RLC) entity: In case the packet repetition technology is configured, multiple RLC entities may be configured for one Packet Data Convergence Protocol (PDCP) entity, and one RLC entity that is not deactivated but is always used from among the multiple RLC entities is referred to as the primary RLC entity. The PDCP entity is characterized in that the PDCP entity does not repeatedly transmit a PDCP control protocol data unit (PDU) and always transmits the PDCP control PDU to the primary RLC entity.

[0070] -Secondary RLC entity: When the packet repetition technology is configured, multiple RLC entities can be configured for one PDCP entity, and the remaining RLC entities except the primary RLC entity among the multiple RLC entities are each called a secondary RLC entity.

[0071] In the present disclosure, a method for dynamically sending zero, one, two or three packet repetitions is provided to further increase reliability and further reduce the transmission waiting time for UEs configured with CA technology, DC technology or packet repetition technology. That is, a method for sending original data and up to three repeated data when sending specific data is provided.

[0072] In the present disclosure, the BS can configure the packet repetition technology for the UE by applying the DC technology or the CA technology via an RRC message. In detail, the BS can configure multiple RLC entities connected to one media access control (MAC) entity, and can configure multiple RLC entities connected to one PDCP entity, and perform packet repetition. As another method, the BS can configure multiple RLC entities connected to one MCG MAC entity, can configure multiple RLC entities connected to one SCG MAC entity, or can configure multiple RLC entities connected to different MAC entities to be connected to one PDCP entity, and by doing so, packet repetition can be performed.

[0073] In addition, the BS can indicate which RLC entity among multiple RLC entities is the primary RLC entity or the secondary RLC entity by using a logical channel identifier and a bearer identifier in an RRC message. For example, the cell group configuration information can indicate the configuration information of each RLC entity, and can indicate the bearer identifier and the logical channel identifier corresponding to each RLC entity. In addition, the bearer configuration information can indicate the configuration information of each PDCP entity, and can indicate the bearer identifier corresponding to each PDCP entity, and in the case where multiple RLC entities are configured for the PDCP entity or the bearer identifier, the BS can indicate the primary RLC entity by indicating the logical channel identifier corresponding to the primary RLC entity. Therefore, when the UE receives the RRC message, the UE can configure the PDCP entity according to the bearer identifier, can configure multiple RLC entities to be connected to the PDCP entity, multiple RLC entities correspond to the bearer identifier, and can specify the primary RLC entity and multiple secondary RLC entities.

[0074] As another method, when the BS configures multiple RLC entities connected to one PDCP entity for the UE by using an RRC message, the BS can indicate which RLC entity among the multiple RLC entities is the primary RLC entity or the secondary RLC entity by using a logical channel identifier (or SCell identifier) ​​and a bearer identifier. For example, the cell group configuration information can indicate the configuration information of each RLC entity, and can indicate the bearer identifier and the logical channel identifier (or SCell identifier) ​​corresponding to each RLC entity. In addition, the bearer configuration information can indicate the configuration information of each PDCP entity, and can indicate the bearer identifier corresponding to each PDCP entity, and in the case where multiple RLC entities are configured for the PDCP entity or the bearer identifier, the BS can indicate the primary RLC entity by indicating the logical channel identifier (or SCell identifier) ​​corresponding to the primary RLC entity. Therefore, when the UE receives the RRC message, the UE can configure the PDCP entity according to the bearer identifier, can configure multiple RLC entities connected to the PDCP entity, multiple RLC entities correspond to the bearer identifier, and can specify the primary RLC entity and multiple secondary RLC entities by using the logical channel identifier or the SCell identifier.

[0075] As another method, when the BS configures multiple RLC entities connected to one PDCP entity for the UE by using an RRC message, the BS can indicate which RLC entity among the multiple RLC entities is the primary RLC entity or the secondary RLC entity by using a new identifier (e.g., an identifier indicating each RLC entity, such as 0, 1, 2, or 3) and a bearer identifier or a logical channel identifier. For example, the cell group configuration information may indicate the configuration information of each RLC entity, and may indicate a bearer identifier and a logical channel identifier or a new identifier corresponding to each RLC entity. In addition, the bearer configuration information may indicate the configuration information of each PDCP entity, and may indicate a bearer identifier corresponding to each PDCP entity, and in the case where multiple RLC entities are configured for the PDCP entity or the bearer identifier, the BS may indicate the primary RLC entity by indicating a logical channel identifier or a new identifier corresponding to the primary RLC entity. A specific value of the new identifier (e.g., an identifier with the lowest value, i.e., 0) may be defined to indicate the primary RLC entity, and RLC entities with different values ​​may be regarded as secondary RLC entities. Therefore, when the UE receives the RRC message, the UE can configure the PDCP entity according to the bearer identifier, can configure multiple RLC entities connected to the PDCP entity, the multiple RLC entities correspond to the bearer identifier, and can specify the primary RLC entity and multiple secondary RLC entities by using a logical channel identifier or a new identifier.

[0076] As another method, for the packet repetition technology, a primary RLC entity is determined from multiple RLC entities connected to one PDCP entity. At this point, the RLC entity with the lowest identifier value or the highest identifier value (minimum identifier value or maximum identifier value) can be configured as the primary RLC entity, and the remaining RLC entities can be configured as secondary RLC entities. The lowest identifier value or the highest identifier value (minimum identifier value or maximum identifier value) can be determined by using one of the following methods. The PDCP entity is characterized in that the PDCP entity does not apply packet repetition on the PDCP control PDU and always sends the PDCP control PDU to the primary RLC entity. In the case of configuring packet repetition for the PDCP data PDU, the PDCP entity sends the data repetition to a secondary RLC entity different from the primary RLC entity. The following method for determining the primary RLC entity can be applied to UE and BS.

[0077] -Method 1: When a new identifier (e.g., 0, 1, 2, and 3) is configured for each RLC entity connected to one PDCP entity through an RRC message, the lowest value or the highest value of the new identifier may be configured (or considered) as a primary RLC entity, and the remaining RLC entities may be configured as secondary RLC entities. Alternatively, when packet repetition is configured, the lowest value or the highest value of the new identifier may be configured as a primary RLC entity among the RLC entities activated by an RRC message or a MAC control element (CE), the RLC entity being from among a plurality of RLC entities connected to the PDCP entity for which packet repetition is configured, and the remaining RLC entities may be configured as secondary RLC entities. Therefore, when the RLC entity activated by the MAC CE changes, the primary RLC entity may be re-determined based on the new identifier value of the changed and activated RLC entity.

[0078] -Method 2: When configuring a logical channel identifier or SCell identifier for each RLC entity connected to one PDCP entity through an RRC message, the lowest value or the highest value of the logical channel identifier or the SCell identifier may be configured as a primary RLC entity, and the remaining RLC entities may be configured as secondary RLC entities. Alternatively, when configuring packet repetition, the lowest value or the highest value of the logical channel identifier or the SCell identifier may be configured as a primary RLC entity among the RLC entities activated by an RRC message or MAC CE indication, the RLC entity being from among a plurality of RLC entities connected to the PDCP entity for which packet repetition is configured, and the remaining RLC entities may be configured as secondary RLC entities. Therefore, when the RLC entity activated by the MAC CE changes, the primary RLC entity may be re-determined based on the logical channel identifier value or the SCell identifier value of the changed and activated RLC entity.

[0079] -Method 3: When a bearer identifier and a logical channel identifier (or SCell identifier) ​​are configured for each RLC entity connected to one PDCP entity through an RRC message, the lowest value or the highest value of the combined value of the bearer identifier and the logical channel identifier (or SCell identifier) ​​(e.g., [bearer identifier + logical channel identifier] or a binary combination [bearer identifier, logical channel identifier]) may be configured as the primary RLC entity, and the remaining RLC entities may be configured as secondary RLC entities. Alternatively, when packet repetition is configured, the lowest value or the highest value of the combined value of the bearer identifier and the logical channel identifier (or SCell identifier) ​​may be configured as the primary RLC entity among the RLC entities activated by the RRC message or MAC CE indication, the RLC entity being from among the multiple RLC entities connected to the PDCP entity for which packet repetition is configured, and the remaining RLC entities may be configured as secondary RLC entities. Therefore, when the RLC entity activated by the MAC CE changes, the primary RLC entity may be re-determined based on the combined value of the bearer identifier and the logical channel identifier (or SCell identifier) ​​of the changed and activated RLC entity.

[0080] As another method, according to a method of dynamically determining a primary RLC entity from among RLC entities activated from among a plurality of RLC entities connected to a PDCP entity for a packet repetition technique, the RLC entity having the lowest identifier value or the highest identifier value (minimum identifier value or maximum identifier value) among the activated RLC entities may always be configured as a primary RLC entity, and the remaining RLC entities may be configured as secondary RLC entities. The lowest identifier value or the highest identifier value (minimum identifier value or maximum identifier value) may be determined by using one of the following methods. The PDCP entity does not apply packet repetition on the PDCP control PDU, and may always send the PDCP control PDU to the primary RLC entity. In the case where packet repetition is configured for the PDCP data PDU, the PDCP entity may repeatedly send data to a secondary RLC entity different from the primary RLC entity. The following method for determining the primary RLC entity may be applied to both the UE and the BS.

[0081] -Method 1: When a new identifier (e.g., 0, 1, 2, and 3) is configured for each RLC entity connected to one PDCP entity through an RRC message, the lowest value or the highest value of the new identifier may be configured as a primary RLC entity, and the remaining RLC entities may be configured as secondary RLC entities. Alternatively, when packet repetition is configured, the lowest value or the highest value of the new identifier may be configured as a primary RLC entity among the RLC entities activated by an RRC message or MAC CE indication, the RLC entity being from among a plurality of RLC entities connected to the PDCP entity for which packet repetition is configured, and the remaining RLC entities may be configured as secondary RLC entities. Therefore, when the RLC entity activated by the MAC CE changes, the primary RLC entity may be re-determined based on the new identifier value of the changed and activated RLC entity.

[0082] -Method 2: When configuring a logical channel identifier or SCell identifier for each RLC entity connected to one PDCP entity through an RRC message, the lowest value or the highest value of the logical channel identifier or the SCell identifier may be configured as a primary RLC entity, and the remaining RLC entities may be configured as secondary RLC entities. Alternatively, when configuring packet repetition, the lowest value or the highest value of the logical channel identifier or the SCell identifier may be configured as a primary RLC entity among the RLC entities activated by an RRC message or MAC CE indication, the RLC entity being from among a plurality of RLC entities connected to the PDCP entity for which packet repetition is configured, and the remaining RLC entities may be configured as secondary RLC entities. Therefore, when the RLC entity activated by the MAC CE changes, the primary RLC entity may be re-determined based on the logical channel identifier value or the SCell identifier value of the changed and activated RLC entity.

[0083] -Method 3: When a bearer identifier and a logical channel identifier (or SCell identifier) ​​are configured for each RLC entity connected to one PDCP entity through an RRC message, the lowest value or the highest value of the combined value of the bearer identifier and the logical channel identifier (or SCell identifier) ​​(e.g., [bearer identifier + logical channel identifier] or a binary combination [bearer identifier, logical channel identifier]) may be configured as the primary RLC entity, and the remaining RLC entities may be configured as secondary RLC entities. Alternatively, when packet repetition is configured, the lowest value or the highest value of the combined value of the bearer identifier and the logical channel identifier (or SCell identifier) ​​may be configured as the primary RLC entity among the RLC entities activated by the RRC message or MAC CE indication, the RLC entity being from among the multiple RLC entities connected to the PDCP entity for which packet repetition is configured, and the remaining RLC entities may be configured as secondary RLC entities. Therefore, when the RLC entity activated by the MAC CE changes, the primary RLC entity may be re-determined based on the combined value of the bearer identifier and the logical channel identifier (or SCell identifier) ​​of the changed and activated RLC entity.

[0084] The above-mentioned method for identifying the primary RLC entity can also be applied to identifying the secondary RLC entity. When the packet repetition process proposed in the present disclosure is applied, a PDCP entity can repeatedly send data by using a structure in which a primary RLC entity and one or more (e.g., one, two, or three) secondary RLC entities are connected, and it is necessary to identify each of the multiple secondary RLC entities. Only when multiple secondary RLC entities configured for each bearer are identified therebetween, can the BS activate or deactivate each of the multiple secondary RLC entities by using MAC control information (e.g., MAC CE). Therefore, hereinafter, a method for identifying each of the multiple secondary RLC entities configured for a bearer configured with packet repetition is provided.

[0085] -Method 4: When a new identifier (e.g., 0, 1, 2, and 3) is configured for each RLC entity connected to one PDCP entity through an RRC message, the BS or UE may configure (or consider) the lowest value of the value of the new identifier as the primary RLC entity, the remaining RLC entities may be configured as secondary RLC entities, and each secondary RLC entity may be identified based on the new identifier. Optionally, when packet repetition is configured, the BS (or UE) may configure the lowest value of the new identifier as the primary RLC entity among the RLC entities activated by indication of the RRC message or MAC CE, the RLC entity is from among the multiple RLC entities connected to the PDCP entity for which packet repetition is configured, the remaining RLC entities may be configured as secondary RLC entities, and each secondary RLC entity may be identified by mapping each bit of the MAC CE to the secondary RLC entity in ascending order of the new identifier. Therefore, the BS may indicate activation or deactivation regarding the primary RLC entity or the secondary RLC entity by using the MAC CE, and when the UE receives the MAC CE, the UE may activate or deactivate the primary RLC entity or the secondary RLC entity corresponding to the MAC CE. As another method, a new identifier may be allocated only to the secondary RLC entity, and a bearer identifier, a logical channel identifier, or a cell group identifier in the PDCP entity configuration information may be used to indicate the primary RLC entity.

[0086] -Method 5: When a logical channel identifier or SCell identifier is configured for each RLC entity connected to one PDCP entity through an RRC message, the BS (or UE) may configure the lowest value of the value of the logical channel identifier or SCell identifier as a primary RLC entity, may configure the remaining RLC entities as secondary RLC entities, and may identify each secondary RLC entity by using the logical channel identifier or SCell identifier. Alternatively, when packet repetition is configured, the BS (or UE) may configure the lowest value of the logical channel identifier or SCell identifier as a primary RLC entity among the RLC entities activated by indication of an RRC message or MAC CE, the RLC entity being from among a plurality of RLC entities connected to the PDCP entity for which packet repetition is configured, and for the remaining RLC entities, the BS (or UE) may identify each secondary RLC entity by mapping respective bits of the MAC CE to the secondary RLC entity in ascending order of the logical channel identifier or SCell identifier (for example, when a plurality of SCell identifiers are mapped to the RLC entity (logical channel identifier), the lowest SCell identifier or the highest SCell identifier is a reference identifier). Therefore, the BS can indicate activation or deactivation of the primary RLC entity or the secondary RLC entity by using MAC CE, and when the UE receives the MAC CE, the UE can activate or deactivate the primary RLC entity or the secondary RLC entity corresponding to the MAC CE. As another method, the logical channel identifier or the SCell identifier can be used only to identify the secondary RLC entity, and the primary RLC entity can be indicated using the bearer identifier, logical channel identifier, or cell group identifier in the PDCP entity configuration information.

[0087] - Method 6: When a bearer identifier and a logical channel identifier (or SCell identifier (for example, when multiple SCell identifiers are mapped to an RLC entity (logical channel identifier)), the lowest SCell identifier or the highest SCell identifier is a reference identifier) ​​are configured for each RLC entity connected to one PDCP entity through an RRC message, the BS (or UE) may configure (or consider) a lowest value of a bearer identifier and a logical channel identifier (or SCell identifier) ​​combination value (for example, a binary combination of [bearer identifier + logical channel identifier] or [bearer identifier, logical channel identifier]) as a primary RLC entity, and may configure the remaining RLC entities as secondary RLC entities. The BS (or UE) may identify each secondary RLC entity based on the combined value of the bearer identifier and the logical channel identifier (or SCell identifier). Optionally, when packet repetition is configured, the BS (or UE) may configure the lowest value of the combined value of the bearer identifier and the logical channel identifier (or SCell identifier) ​​as the primary RLC entity. The CE indicates a primary RLC entity among the activated RLC entities, the RLC entity being from among a plurality of RLC entities connected to the PDCP entity for which packet repetition is configured, and for the remaining RLC entities, the BS (or UE) can identify each secondary RLC entity by mapping the respective bits of the MAC CE to the secondary RLC entity in ascending order of a combined value of a bearer identifier and a logical channel identifier (or SCell identifier) ​​(e.g., [bearer identifier+logical channel identifier] or a binary combination [bearer identifier, logical channel identifier]). Therefore, the BS can indicate activation or deactivation of the primary RLC entity or the secondary RLC entity by using the MAC CE, and when the UE receives the MAC CE, the UE can activate or deactivate the primary RLC entity or the secondary RLC entity corresponding to the MAC CE. As another method, the bearer identifier and the logical channel identifier (or SCell identifier) ​​can be used only to identify the secondary RLC entity, and the primary RLC entity can be indicated using the bearer identifier, the logical channel identifier, or the cell group identifier in the PDCP entity configuration information.

[0088] - Method 7: When configuring a cell group identifier and a logical channel identifier (or SCell identifier (for example, when multiple SCell identifiers are mapped to an RLC entity (logical channel identifier)), the lowest SCell identifier or the highest SCell identifier is a reference identifier) ​​for each RLC entity connected to one PDCP entity via an RRC message, the BS (or UE) may configure (or consider) the lowest value of a combination value of the cell group identifier and the logical channel identifier (or SCell identifier) ​​(for example, [cell group identifier + logical channel identifier (or SCell identifier)] or a binary combination [cell group identifier, logical channel identifier]]) as a primary RLC entity, and may configure the remaining RLC entities as secondary RLC entities. The BS (or UE) may identify each secondary RLC entity based on the combination value of the cell group identifier and the logical channel identifier (or SCell identifier). Optionally, when group repetition is configured, the BS (or UE) may configure the lowest value of the combination value of the cell group identifier and the logical channel identifier (or SCell identifier) ​​as the primary RLC entity. The CE indicates a primary RLC entity among the activated RLC entities, the RLC entity being from among a plurality of RLC entities connected to a PDCP entity for which packet repetition is configured, and for the remaining RLC entities, the BS (or UE) can identify each secondary RLC entity by mapping the respective bits of the MACCE to the secondary RLC entity in ascending order of a combined value of a cell group identifier and a logical channel identifier (or SCell identifier) ​​(e.g., [cell group identifier+logical channel identifier] or a binary combination [cell group identifier, logical channel identifier]). Therefore, the BS can indicate activation or deactivation of the primary RLC entity or the secondary RLC entity by using the MAC CE, and when the UE receives the MAC CE, the UE can activate or deactivate the secondary RLC entity corresponding to the MAC The primary RLC entity or secondary RLC entity of the CE. As another method, the cell group identifier and the logical channel identifier (or SCell identifier) ​​can be used only to identify the secondary RLC entity, and the primary RLC entity can be indicated using the bearer identifier, logical channel identifier or cell group identifier in the PDCP entity configuration information. As another method, when the packet repetition transmission technology is applied to the DC technology, the BS (or UE) can first map the RLC entities of the MCG (or SCG) to bits in ascending order of the logical channel identifiers, and then the RLC entities of the SCG (or MCG) can be mapped to bits in ascending order of the logical channel identifiers.

[0089] -Method 8: When configuring a cell group identifier, a bearer identifier, or a logical channel identifier for each RLC entity connected to one PDCP entity via an RRC message, the BS (or UE) may configure the lowest value of the combined value of the cell group identifier, the bearer identifier, or the logical channel identifier as the primary RLC entity, and may configure the remaining RLC entities as secondary RLC entities. The BS (or UE) may identify each secondary RLC entity based on the combined value of the cell group identifier, the bearer identifier, or the logical channel identifier. Optionally, when configuring packet repetition, the BS (or UE) may configure the lowest value of the combined value of the cell group identifier, the bearer identifier, or the logical channel identifier as the primary RLC entity among the RLC entities activated by the RRC message or MAC CE indication, the RLC entity being from among the multiple RLC entities connected to the PDCP entity for which packet repetition is configured, and for the remaining RLC entities, the BS (or UE) may identify each secondary RLC entity by mapping the respective bits of the MAC CE to the secondary RLC entity in ascending order of the combined value of the cell group identifier, the bearer identifier, or the logical channel identifier. Therefore, the BS can indicate activation or deactivation of the primary RLC entity or the secondary RLC entity by using MAC CE, and when the UE receives the MAC CE, the UE can activate or deactivate the primary RLC entity or the secondary RLC entity corresponding to the MAC CE. As another method, the cell group identifier and the logical channel identifier (or SCell identifier) ​​can be used only to identify the secondary RLC entity, and the primary RLC entity can be indicated using the bearer identifier, logical channel identifier, or cell group identifier in the PDCP entity configuration information.

[0090] The reason why a method for identifying a secondary RLC entity is needed is that the logical channel identifier assigned to each RLC entity is an identifier that is unique only in one MAC entity. Figure 1G In 1g-02, when the DC technology is configured and the packet repetition transmission technology is configured, RLC entity 1 and RLC entity 2 are connected to one MAC entity and therefore have different logical channel identifiers, and RLC entity 3 and RLC entity 4 are connected to one MAC entity and therefore have different logical channel identifiers. However, RLC entity 1 may have the same logical channel identifier as RLC entity 3 or RLC entity 4 connected to another MAC entity, and RLC entity 2 may have the same logical channel identifier as RLC entity 3 or RLC entity 4 connected to another MAC entity. Therefore, by using only the logical channel identifier, the secondary RLC entities may not be distinguishable from each other.

[0091] Therefore, according to an embodiment of the present disclosure, taking into account a bearer identifier, an SCell identifier, or a cell group identifier, as in method 4, method 5, method 6, method 7, or method 8, a BS (or UE) may identify each secondary RLC entity, and may allow a bit of a MAC CE and a corresponding RLC entity (a primary RLC entity or a secondary RLC entity) to be mapped one-to-one based on identification information (e.g., a bearer identifier, an SCell identifier, or a cell group identifier) ​​so as to indicate activation or deactivation by using each bit to indicate 0 or 1. In addition, as in method 4, method 5, method 6, method 7, or method 8, a new RLC identifier may be newly defined, applied, and used based on a bearer identifier, a cell identifier, or a cell group identifier to identify a corresponding RLC entity.

[0092] With respect to multiple RLC entities connected to a PDCP entity of a bearer for which packet repetition is configured using an RRC message, in a case where the UE receives an indication of a change in a primary RLC entity due to an indication of a MAC CE or a change in the primary RLC entity due to an indication of activation or deactivation of each RLC entity relative to multiple RLC entities, the MAC entity that received the MAC CE indicates to the PDCP entity which RLC entity among the multiple RLC entities is the primary RLC entity or the secondary RLC entity, so that the PDCP control data can be correctly sent only to the primary RLC entity during the packet repetition process.

[0093] With respect to a plurality of RLC entities connected to a PDCP entity for which a bearer is configured with packet repetition using an RRC message, in a case where the UE activates only one RLC entity and deactivates all remaining RLC entities (e.g., secondary RLC entities) due to an indication of a MAC CE (i.e., an indication of activation or deactivation of each RLC entity of the plurality of RLC entities), the UE may regard this as deactivation of packet repetition, and the MAC entity that has received the MAC CE indicates to the PDCP entity that the packet repetition technique is deactivated, thereby controlling the PDCP entity to stop application of the packet repetition technique. In a case where only one RLC entity is activated with respect to a plurality of RLC entities, when two or more RLC entities are activated due to receiving a MAC CE (activating a primary RLC entity and at least one secondary RLC entity), the MAC entity that has received the MAC CE indicates to the PDCP entity that packet repetition and the activated RLC entity (e.g., an identifier) ​​are activated, thereby controlling the PDCP entity to apply packet repetition to the activated RLC entity.

[0094] In the case where multiple RLC entities connected to a PDCP entity for a bearer configured with a packet repetition using an RRC message are configured, when the UE autonomously determines which RLC entities are to be activated (or are to be used for transmission of repeated data) or are to be deactivated (or are not to be used for transmission of repeated data) based on channel measurement information of the SCell mapped to the RLC entity, the UE can determine the primary RLC entity from the determined activated RLC entities, and can indicate to the PDCP entity which RLC entity is the primary RLC entity or the secondary RLC entity (or which RLC entities can be used for transmission of repeated data), so that the PDCP entity can correctly process the PDCP control data. In the case where only one RLC entity among the determined activated RLC entities (or RLC entities for transmission of repeated data) is activated (or used for transmission of repeated data), the UE can indicate to the PDCP entity the deactivation of packet repetition, and in the case where two or more RLC entities are to be activated (or used for transmission of repeated data), the UE can indicate to the PDCP entity the activation of packet repetition and the activated RLC entity (or the RLC entity used in repeated data transmission), so that the PDCP entity can perform the packet repetition process. When the UE autonomously determines which RLC entities will be activated (or will be used for transmission of repeated data) or will be deactivated (or will not be used for transmission of repeated data) based on the channel measurement information of the SCell mapped to the RLC entity, the UE can indicate information about the activated RLC entity (or the RLC entity determined to be used for transmission of repeated data) or information about the primary RLC entity or the secondary RLC entity to the BS by using MAC CE, RLC control PDU or PDCP control PDU, thereby notifying the UE of information about application of the packet repetition technology. Therefore, the BS can be notified of which RLC entity receives PDCP control data or whether the packet repetition technology is to be applied.

[0095] Hereinafter, various embodiments of designing a MACCE for applying a packet repetition technique to a plurality of RLC entities are provided.

[0096] As proposed in the present disclosure, in the case where multiple RLC entities connected to a PDCP entity for which a packet repetition technology is configured are configured for the same MAC entity and then the packet repetition technology is applied based on the CA technology, the RLC entity may have a cell mapping restriction, through which the RLC entities are respectively mapped to different PCells, PSCells or SCells, and duplicate data is sent. As proposed in the present disclosure, in the case where multiple RLC entities connected to a PDCP entity for which a packet repetition technology is configured are configured for different MAC entities and then the packet repetition technology is applied based on the DC technology, the RLC entity may have a cell mapping restriction, through which the RLC entities are respectively mapped to different PCells, PSCells or SCells, and duplicate data is sent. As proposed in the present disclosure, some of the multiple RLC entities connected to the PDCP entity for which the packet repetition technology is configured are configured for the same MAC entity, so that the packet repetition technology based on the CA technology can be applied thereto, and some RLC entities are configured for different MAC entities, so that the packet repetition technology based on the DC technology can be applied thereto, and the RLC entities can have cell mapping restrictions, through which the RLC entities are respectively mapped to different PCells, PSCells or SCells in one MAC entity and send repeated data.

[0097] As proposed in the present disclosure, in a case where all or some of the multiple RLC entities connected to a PDCP entity for which a packet repetition technology is configured are configured for one MAC entity and a packet repetition technology based on a CA technology is applied thereto, the RLC entity may have a cell mapping restriction, by which the RLC entities configured for one MAC entity are respectively mapped to different PCells, PSCells, or SCells, and repeat data is sent. In a case where a packet repetition technology based on a CA technology configured for one MAC entity is deactivated, in data transmission, the cell mapping restriction may not be applied to the multiple RLC entities connected to the PDCP entity for which a packet repetition technology is configured, and in a case where a packet repetition technology based on a CA technology configured for one MAC entity is activated, the cell mapping restriction may be applied again to data transmission. As proposed in the present disclosure, in a case where all or some of the multiple RLC entities connected to a PDCP entity for which a packet repetition technology is configured are configured for different MAC entities and a packet repetition technology based on a DC technology is applied thereto, the RLC entities configured for different MAC entities may have a cell mapping restriction, by which the RLC entities are respectively mapped to different PCells, PSCells, or SCells, and repeat data is sent. Even when the packet repetition technology based on the DC technology configured for a different MAC entity is deactivated, the cell mapping restriction regarding the RLC entity connected to the PDCP entity for which the packet repetition technology is configured and connected to the different MAC entity can be continuously applied to data transmission.

[0098] For example, it can be assumed that RLC entity 1 and RLC entity 2 among RLC entity 1, RLC entity 2, RLC entity 3 and RLC entity 4 connected to a PDCP entity configured with a packet repetition technology are connected to MAC entity 1, and RLC entity 3 and RLC entity 4 are connected to MAC entity 2. The RLC entity may be configured with a cell mapping restriction on each MAC entity. In the case where packet repetition is performed based on CA technology via MAC entity 1 by using RLC entity 1 and RLC entity 2, the cell mapping restriction on RLC entity 1 and RLC entity 2 may be applied. However, when packet repetition based on CA technology is deactivated, the cell mapping restriction may not be applied to RLC entity 1 and RLC entity 2. In the case where packet repetition is performed based on DC technology via MAC entity 2 by using RLC entity 1 and RLC entity 3, the cell mapping restriction on RLC entity 1 and RLC entity 3 may be applied. However, even when packet repetition based on CA technology is deactivated, the cell mapping restriction may continue to be applied to RLC entity 1 and RLC entity 2. Because when different MAC entities configure different frequencies, different MAC entities already have multiplexing gains. Therefore, in the case where packet repetition is performed via MAC entity 1 based on the CA technology by using RLC entity 1 and RLC entity 2, and packet repetition is performed via MAC entity 2 based on the DC technology by using RLC entity 3 at the same time, cell mapping restriction may be applied to RLC entity 1, RLC entity 2, and RLC entity 3. However, when packet repetition based on the CA technology and the DC technology is deactivated, the cell mapping restriction is not applied to RLC entity 1 and RLC entity 2, and the cell mapping restriction is continuously applied to RLC entity 3.

[0099] In the present disclosure, an embodiment of configuring one primary RLC entity and configuring up to three secondary RLC entities is considered, and the embodiments provided in the present disclosure can be widely applied to embodiments of configuring one or more primary RLC entities or one or more secondary RLC entities.

[0100] Figure 1A is a diagram showing a configuration of an LTE system according to an embodiment of the present disclosure.

[0101] refer to Figure 1A , the radio access network (RAN) of the LTE system includes multiple evolved Node Bs (eNBs) (or Node Bs or BSs) 1a-05, 1a-10, 1a-15, and 1a-20, a mobility management entity (MME) 1a-25, and a serving gateway (S-GW) 1a-30. UE (or terminal) 1a-35 can access an external network through eNBs 1a-05, 1a-10, 1a-15, or 1a-20 and S-GW 1a-30.

[0102] exist Figure 1A In the LTE system, eNB 1a-05, 1a-10, 1a-15 or 1a-20 may correspond to an existing Node B of a Universal Mobile Telecommunications System (UMTS). The eNB is connected to UE 1a-35 through a wireless channel and performs complex functions compared to the existing Node B. All user traffic data including real-time services such as Voice over Internet Protocol (VoIP) may be served through a shared channel in the LTE system, so an entity for collating the state information of the UE (e.g., buffer state information, available transmission power state information, and channel state information) and performing scheduling may be required, and eNB 1a-05, 1a-10, 1a-15 or 1a-20 may operate as such an entity. One eNB typically controls multiple cells. For example, the LTE system may use a radio access technology such as OFDM at a bandwidth of 20 MHz to achieve a data rate of 100 Mbps. In addition, adaptive modulation and coding (AMC) may be used to determine a modulation scheme and a channel coding rate according to the channel state of the UE. The S-GW 1a-30 is an entity for providing a data bearer, and can establish and release the data bearer by the control of the MME 1a-25. The MME 1a-25 is an entity for performing a mobility management function and various control functions on the UE, and is connected to a plurality of eNBs.

[0103] Figure 1B is a diagram showing a radio protocol architecture of an LTE system according to an embodiment of the present disclosure.

[0104] refer to Figure 1B , the radio protocol architecture of the LTE system may include PDCP entities 1b-05 and 1b-40, RLC entities 1b-10 and 1b-35, and MAC entities 1b-15 and 1b-30 for UE and eNB respectively. The PDCP entity 1b-05 or 1b-40 may perform, for example, IP header compression / decompression. The main functions of the PDCP entity are summarized as follows. However, its functions are not limited thereto.

[0105] -Header compression and decompression: Powerful header compression (ROHC only)

[0106] -Transmission of user data

[0107] - In-sequence delivery of upper layer packet data units (PDUs) during PDCP re-establishment in RLC Acknowledged Mode (AM)

[0108] - For split bearer of DC (supports RLC AM only): PDCP PDU routing for transmission and PDCP PDU reordering for reception

[0109] - Duplicate detection of lower layer service data units (SDUs) during PDCP re-establishment procedure of RLC AM

[0110] - Retransmit PDCP PDUs during handover. For split bearers of DC, retransmit PDCP PDUs during PDCP data recovery of RLC AM.

[0111] -Encryption and decryption

[0112] - Timer-based SDU discard in uplink

[0113] The RLC entity 1b-10 or 1b-35 may perform an automatic repeat request (ARQ) operation by reconfiguring the PDCP PDU to an appropriate size. The main functions of the RLC entity are summarized as follows. However, its functions are not limited thereto.

[0114] -Transmission of upper layer PDU

[0115] - Error correction via ARQ (only applicable to AM data transmission)

[0116] - Concatenation, segmentation and reassembly of RLC SDUs (only for Unacknowledged Mode (UM) and AM data transmission)

[0117] - Re-segmentation of RLC data PDUs (applicable only for AM data transmission)

[0118] - Reordering of RLC data PDUs (applicable only for UM and AM data transmission)

[0119] - Duplicate detection (applicable only for UM and AM data transmission)

[0120] - Protocol error detection (only for AM data transmission)

[0121] -RLC SDU discard (only for UM and AM data transmission)

[0122] -RLC reconstruction

[0123] The MAC entity 1b-15 or 1b-30 can be connected to multiple RLC entities configured for one UE, and can multiplex RLC PDUs into MAC PDUs, and can demultiplex RLC PDUs from MAC PDUs. The main functions of the MAC entity can be summarized as follows. However, its functions are not limited to this.

[0124] - Mapping between logical channels and transport channels

[0125] - Multiplexing MAC SDUs belonging to one or more different logical channels into a transport block (TB) transmitted to or from the physical layer on a transport channel / demultiplexing MAC SDUs belonging to one or more different logical channels from a transport block (TB) transmitted to or from the physical layer on a transport channel

[0126] -Dispatch information report

[0127] - Error correction through Hybrid ARQ (HARQ)

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

[0129] - Prioritization between UEs through dynamic scheduling

[0130] -Multimedia Broadcast / Multicast Service (MBMS) service identifier

[0131] -Transmission format selection

[0132] -filling

[0133] The PHY entity 1b-20 or 1b-25 may encode and modulate the upper layer data channel into an OFDM symbol and transmit the OFDM symbol through a wireless channel, or may demodulate an OFDM symbol received through a wireless channel and channel-decode and transmit the OFDM symbol to an upper layer. However, its function is not limited thereto.

[0134] Figure 1C is a diagram illustrating a next generation mobile communication system according to an embodiment of the present disclosure.

[0135] refer to Figure 1C As shown in the figure, the radio access network of the next generation mobile communication system (hereinafter referred to as NR or 5G communication system) includes a new radio node B (NR gNB, NR NB or gNB) 1c-10 and a new radio core network (NRCN) 1c-05. NRUE (or terminal) 1c-15 can access the external network via NR gNB1c-10 and NR CN 1c-05.

[0136] exist Figure 1CIn the NR gNB 1c-10, the NR gNB 1c-10 may correspond to an existing eNB of the LTE system. The NR gNB1c-10 may be connected to the NR UE 1c-15 through a radio channel and may provide better services than the existing Node B. All user service data may be served through a shared channel in the NR or 5G mobile communication system, and therefore, an entity for collating the buffer status information, available transmission power status information, and channel status information of the UE and performing scheduling may be required, and the NR gNB1c-10 may operate as such an entity. One NR gNB typically controls multiple cells. Compared with the existing LTE system, the NR or 5G communication system may have a larger bandwidth than the maximum bandwidth of the existing LTE system in order to achieve an ultra-high data rate, and may use OFDM as a radio access technology, and may additionally use beamforming technology. In addition, AMC may be used to determine the modulation scheme and channel coding rate according to the channel state of the UE. The NR CN 1c-05 may perform functions such as mobility support, bearer configuration, and quality of service (QoS) configuration. NR CN 1c-05 is an entity for performing mobility management functions and various control functions on NR UE 1c-15 and is connected to multiple base stations. The NR or 5G mobile communication system can cooperate with the existing LTE system, and the NR CN 1c-05 can be connected to the MME 1c-25 through a network interface. The MME 1c-25 can be connected to the existing eNB 1c-30.

[0137] Figure 1D is a diagram showing a radio protocol architecture of an NR or 5G mobile communication system according to an embodiment of the present disclosure.

[0138] refer to Figure 1D , the radio protocol architecture of the NR or 5G mobile communication system may include NR Service Data Adaptation Protocol (SDAP) entities 1d-01 and 1d-45, NR PDCP entities 1d-05 and 1d-40, NR RLC entities 1d-10 and 1d-35, and NR MAC entities 1d-15 and 1d-30 for UE and NR gNB, respectively.

[0139] The main functions of NR SDAP entity 1d-01 or 1d-45 may include the following functions. However, its functions are not limited to these.

[0140] -Transmission of user plane data

[0141] -Mapping between QoS flows and DRBs for DL ​​and UL

[0142] - Marking QoS flow identifier (ID) in DL and UL packets

[0143] -Reflective QoS flow to DRB mapping for UL SDAP PDU

[0144] For the SDAP entity, information about whether to use the header of the SDAP entity or the function of the SDAP entity can be configured for the UE by using an RRC message for each PDCP entity, each bearer, or each logical channel. When the SDAP header of the SDAP entity is configured, the UE can indicate that the UL and DL QoS flows and data bearer mapping information are updated or reconfigured by using a 1-bit non-access stratum (NAS) reflected QoS indicator and a 1-bit access stratum (AS) reflected QoS indicator of the SDAP header. The SDAP header may include QoS flow ID information indicating QoS. The QoS information can be used as data processing priority information or scheduling information for appropriately supporting services.

[0145] The main functions of the NR PDCP layer 1d-05 or 1d-40 may include the following functions. However, its functions are not limited to these.

[0146] -Header compression and decompression: ROHC only

[0147] -Transmission of user data

[0148] - Sequential delivery of upper layer PDUs

[0149] - Out-of-order delivery of upper layer PDUs

[0150] - Reordering of received PDCP PDUs

[0151] - Duplicate detection of lower layer SDU

[0152] -Retransmission of PDCP SDU

[0153] -Encryption and decryption

[0154] - Timer-based SDU discard in uplink

[0155] The reordering function of the NR PDCP entity may include at least one of a function of reordering PDCP PDUs received from a lower layer on the basis of a PDCP sequence number (SN) and a function of delivering the reordered data to a higher layer in sequence. Alternatively, the reordering function of the NR PDCP entity may include at least one of the following functions: a function of delivering the reordered data to an upper layer out of sequence, a function of recording lost PDCP PDUs by reordering received PDCP PDUs, a function of reporting status information of lost PDCP PDUs to a transmitter, and a function of requesting retransmission of lost PDCP PDUs.

[0156] The main functions of the NR RLC entity 1d-10 or 1d-35 may include the following functions. However, its functions are not limited to these.

[0157] -Transmission of upper layer PDU

[0158] - Sequential delivery of upper layer PDUs

[0159] - Out-of-order delivery of upper layer PDUs

[0160] - Error correction via ARQ

[0161] - Concatenation, segmentation and reassembly of RLC SDU

[0162] - Re-segmentation of RLC data PDUs

[0163] - Reordering of RLC data PDUs

[0164] - Duplicate detection

[0165] -Protocol error detection

[0166] -RLC SDU discarded

[0167] -RLC reconstruction

[0168] The sequential delivery function of the NR RLC entity indicates a function of delivering the RLC SDU received from the lower layer to the upper layer in sequence. The sequential delivery function of the NR RLC entity may include at least one of the following functions: a function of reassembling the RLC SDU and transmitting the reassembled RLC SDU when multiple RLC SDUs segmented from one RLC SDU are received; a function of reordering the received RLC PDU based on the RLC SN or PDCP SN; a function of recording the lost RLC PDU by reordering the received RLC PDU; a function of reporting the status information of the lost RLC PDU to the transmitter; a function of requesting retransmission of the lost RLC PDU; a function of delivering only the RLC PDU before the lost RLC SDU in sequence when the lost RLC SDU exists; or a function of delivering all RLC PDUs received before the timer starts to the upper layer in sequence despite the existence of the lost RLC PDU when a certain timer stops.

[0169] The out-of-order delivery function of the NR RLC entity may process the RLC PDU in the order of reception and deliver the RLC PDU to the NR PDCP entity regardless of the SN (out-of-order delivery), and when a segment is received, the NR RLC entity may reassemble the segment with other segments stored in a buffer or received subsequently into a whole RLC PDU, and may deliver the RLC PDU to the NR PDCP entity. According to some embodiments of the present disclosure, the NR RLC entity may not have a connection function, and the connection function may be performed by the NR MAC entity or replaced by a multiplexing function of the NR MAC entity.

[0170] The out-of-order delivery function of the NR RLC may include a function of directly delivering the RLC SDU received from the lower layer to the upper layer out of order. The out-of-order delivery function of the NR RLC entity may include at least one of the following functions: a function of reassembling a plurality of RLC PDUs segmented from one RLC SDU and transmitting the reassembled RLC SDU upon receiving the segmented RLC PDU; or a function of recording the lost RLC PDU by storing the RLC SN or PDCP SN of the received RLC PDU and reordering the received RLC PDU.

[0171] The NR MAC entity can be connected to multiple NR RLC entities configured for one UE, and the main functions of the NR MAC entity may include some of the following functions. However, its functions are not limited to this.

[0172] - Mapping between logical channels and transport channels

[0173] -Multiplexing / demultiplexing of MAC SDU

[0174] -Dispatch information report

[0175] - Error correction through HARQ

[0176] - Priority handling between logical channels of a UE

[0177] - Prioritization between UEs through dynamic scheduling

[0178] -MBMS service logo

[0179] -Transmission format selection

[0180] -filling

[0181] The NR PHY entity 1d-20 or 1d-25 may encode and modulate an upper layer data channel into an OFDM symbol, and may send the OFDM symbol through a wireless channel, or may demodulate and perform channel decoding on an OFDM symbol received through a wireless channel, and may transmit the OFDM symbol to an upper layer.

[0182] In the present disclosure, a bearer may include an SRB and a DRB, where SRB stands for a signaling radio bearer and DRB stands for a data radio bearer. A UM DRB indicates that the DRB is configured to use an RLC entity operating in an unacknowledged mode (UM), and an acknowledged mode (AM) DRB indicates that the DRB is configured to use an RLC entity operating in AM. SRB0 refers to an undecoded SRB configured for the MCG of the UE, through which the UE exchanges RRC messages with the BS. SRB1 refers to an encrypted SRB configured for the MCG of the UE, through which the BS and the UE exchange RRC messages for establishing important connections. SRB2 refers to an encrypted SRB configured for the MCG of the UE, through which the BS and the UE establish a connection and exchange RRC messages related to NAS. SRB3 refers to an encrypted SRB configured for the SCG of the UE, through which the UE can send RRC messages directly to the MCG via the SCG MAC entity. A separated SRB refers to an SRB through which one PDCP entity exists in an MCG or SCG and two RLC entities are connected to one PDCP entity to perform data transmission and reception, wherein one RLC entity is connected to an MCG MAC entity and the other RLC entity is connected to an SCG MAC entity.

[0183] Figure 1E It is a diagram for describing the process of UE switching from RRC idle mode or RRC inactive mode to RRC connected mode, and BS configuring CA technology, DC technology or packet repetition technology for UE in the next generation mobile communication system according to an embodiment of the present disclosure.

[0184] refer to Figure 1E , due to some reasons, the BS may switch the RRC connection mode of the UE connected to the network to the RRC idle mode or the RRC inactive mode. Some reasons may include the BS lacking scheduling resources, stopping data transmission or reception with the UE for a certain period of time, etc.

[0185] The BS may send an RRCRelease message to the UE, thereby instructing the UE to transition to the RRC idle mode or the RRC inactive mode. The BS may instruct the UE to transition to the RRC inactive mode by using an indicator (suspend-config) included in the RRCRelease message. When the indicator (suspend-config) is not included in the RRCRelease message, the UE may transition to the RRC idle mode (1e-05).

[0186] When a UE that has transitioned to RRC idle mode or RRC inactive mode requests connection to a network for some reason, the UE may perform a random access procedure, may receive a random access response, may request an RRC connection establishment, may receive an RRC message, and may thus perform an RRC connection establishment (1e-10, 1e-15, 1e-20, 1e-25, 1e-30, 1e-35, and 1e-40).

[0187] The UE establishes reverse transmission synchronization with the BS through a random access procedure and sends an RRCSetupRequest message or an RRCResumeRequest message (when the UE is in RRC inactive mode) to the BS (1e-25). The RRCSetupRequest message or the RRCResumeRequest message (when the UE is in RRC inactive mode) may include the UE identifier, establishment cause, etc.

[0188] The BS sends an RRCSetup message or an RRCResume message (when the UE is in RRC inactive mode) to allow the UE to establish an RRC connection (1e-30). The RRCSetup message or the RRCResume message (when the UE is in RRC inactive mode) may include at least one of configuration information for each logical channel, configuration information for each bearer, configuration information for the RLC entity, and configuration information for the MAC entity.

[0189] The RRCSetup message or the RRCResume message (when the UE is in RRC inactive mode) can allocate a bearer identifier (e.g., an SRB identifier or a DRB identifier) ​​for each bearer and can indicate the configuration of the PDCP entity, the RLC entity, the MAC entity, and the PHY entity relative to each bearer. In addition, the RRCSetup message or the RRCResume message (when the UE is in RRC inactive mode) can configure the packet repetition transmission technology.

[0190] The BS may configure a packet repetition technique for the UE by applying the DC technique or the DC technique via an RRC message. In detail, the BS may configure a plurality of RLC entities connected to one MAC entity, and may configure a plurality of RLC entities connected to one PDCP entity, and perform packet repetition.

[0191] As another method, the BS may configure multiple RLC entities connected to one MCG MAC entity to be connected to one PDCP entity, may configure multiple RLC entities connected to one SCG MAC entity to be connected to one PDCP entity, or may configure multiple RLC entities connected to different MAC entities to be connected to one PDCP entity, and by doing so, packet repetition can be performed.

[0192] In addition, the BS can indicate which RLC entity among multiple RLC entities is the primary RLC entity or the secondary RLC entity by using a logical channel identifier and a bearer identifier in an RRC message. For example, the cell group configuration information can indicate the configuration information of each RLC entity, and can indicate the bearer identifier and the logical channel identifier corresponding to each RLC entity. In addition, the bearer configuration information can indicate the configuration information of each PDCP entity, and can indicate the bearer identifier corresponding to each PDCP entity, and in the case where multiple RLC entities are configured for the PDCP entity or the bearer identifier, the BS can indicate the primary RLC entity by indicating the logical channel identifier corresponding to the primary RLC entity. Therefore, when the UE receives the RRC message, the UE can configure the PDCP entity according to the bearer identifier, can configure multiple RLC entities to be connected to the PDCP entity, multiple RLC entities correspond to the bearer identifier, and can specify the primary RLC entity and multiple secondary RLC entities.

[0193] As another method, when the BS configures multiple RLC entities connected to one PDCP entity by using an RRC message, the BS can indicate which RLC entity among the multiple RLC entities is the primary RLC entity or the secondary RLC entity by using a logical channel identifier (or SCell identifier) ​​and a bearer identifier. For example, the cell group configuration information can indicate the configuration information of each RLC entity, and can indicate the bearer identifier and the logical channel identifier (or SCell identifier) ​​corresponding to each RLC entity. In addition, the bearer configuration information can indicate the configuration information of each PDCP entity, and can indicate the bearer identifier corresponding to each PDCP entity, and in the case where multiple RLC entities are configured for the PDCP entity or the bearer identifier, the BS can indicate the primary RLC entity by indicating the logical channel identifier (or SCell identifier) ​​corresponding to the primary RLC entity. Therefore, when the UE receives the RRC message, the UE can configure the PDCP entity according to the bearer identifier, can configure multiple RLC entities connected to the PDCP entity, multiple RLC entities correspond to the bearer identifier, and can specify the primary RLC entity and multiple secondary RLC entities by using the logical channel identifier or the SCell identifier.

[0194] As another method, when the BS configures multiple RLC entities connected to one PDCP entity by using an RRC message, the BS can indicate which RLC entity among the multiple RLC entities is a primary RLC entity or a secondary RLC entity by using a new identifier (e.g., an identifier indicating each RLC entity, such as 0, 1, 2, or 3) and a bearer identifier or a logical channel identifier. For example, the cell group configuration information may indicate configuration information of each RLC entity, and may indicate a bearer identifier and a logical channel identifier or a new identifier corresponding to each RLC entity. In addition, the bearer configuration information may indicate configuration information of each PDCP entity, and may indicate a bearer identifier corresponding to each PDCP entity, and in the case where multiple RLC entities are configured for a PDCP entity or a bearer identifier, the BS may indicate the primary RLC entity by indicating a logical channel identifier or a new identifier corresponding to the primary RLC entity. A specific value of the new identifier (e.g., an identifier with the lowest value, i.e., 0) may be defined to indicate a primary RLC entity, and RLC entities with different values ​​may be regarded as secondary RLC entities. Therefore, when the UE receives the RRC message, the UE can configure the PDCP entity according to the bearer identifier, can configure multiple RLC entities connected to the PDCP entity, the multiple RLC entities correspond to the bearer identifier, and can specify the primary RLC entity and multiple secondary RLC entities by using a logical channel identifier or a new identifier.

[0195] As another method, for the packet repetition technology, a primary RLC entity is determined from multiple RLC entities connected to one PDCP entity. At this point, the RLC entity with the lowest identifier value or the highest identifier value (minimum identifier value or maximum identifier value) can be configured as the primary RLC entity, and the remaining RLC entities can be configured as secondary RLC entities. The lowest identifier value or the highest identifier value (minimum identifier value or maximum identifier value) can be determined by using one of the above methods. The PDCP entity does not apply packet repetition on the PDCP control PDU, and the PDCP control PDU can always be sent to the primary RLC entity. In the case of configuring packet repetition for the PDCP data PDU, the PDCP entity can repeatedly send data to a secondary RLC entity that is different from the primary RLC entity. The following method for determining the primary RLC entity can be applied to UE and BS.

[0196] The UE that establishes an RRC connection sends an RRCSetupComplete message or an RRCResumeComplete message (when the UE is in RRC inactive mode) to the BS (1e-40). The RRCSetupComplete message or the RRCResumeComplete message (when the UE is in RRC inactive mode) may include a control message of SERVICE REQUEST, which is requested by the UE to the Access and Mobility Function (AMF) or MME to perform bearer configuration for a specific service. The BS may send a SERVICE REQUEST message included in the RRCConnectionSetupComplete message or the RRCResumeComplete message to the AMF or MME (when the UE is in RRC inactive mode), and the AMF or MME may determine whether to provide the service requested by the UE.

[0197] As a result of the determination, when the AMF or MME determines to provide the service requested by the UE, the AMF or MME sends an initial context setup request (INITIAL CONTEXT SETUP REQUEST) message to the BS. The initial context setup request message may include quality of service (QoS) information to be applied to the DRB configuration, security information to be applied to the DRB (e.g., security keys, security algorithms, etc.), etc.

[0198] The BS transmits and receives a SecurityModeCommand message and a SecurityModeComplete message to and from the UE to configure security, and when configuration of the security is completed, the BS transmits an RRCConnectionReconfiguration message to the UE (1e-45).

[0199] The RRCConnectionReconfiguration message may allocate a bearer identifier (eg, an SRB identifier or a DRB identifier) ​​for each bearer, and may indicate configuration of a PDCP entity, an RLC entity, a MAC entity, and a PHY entity for each bearer.

[0200] In addition, the RRCConnectionReconfiguration message can configure additional SCells to configure CA technology for the UE, or can provide and configure additional SCG configuration information to configure DC technology.

[0201] The RCConnectionReconfiguration message may include configuration information about the DRB to process user data, and the UE may configure the DRB by using the configuration information about the DRB, and may send an RRCConnectionReconfigurationComplete message to the BS (1e-45). After the BS completes the DRB configuration with the UE, the BS may send an Initial Context Setup Complete message to the AMF or MME, and may complete the connection (1e-50).

[0202] In addition, the RRCConnectionReconfiguration message may configure the packet repetition transmission technique. In the present disclosure, the BS may configure the packet repetition technique for the UE by applying the DC technique or the CA technique via an RRC message.

[0203] In detail, the BS may configure a plurality of RLC entities connected to one MAC entity, and may configure a plurality of RLC entities connected to one PDCP entity, and perform packet repetition.

[0204] As another method, the BS may configure multiple RLC entities connected to one MCG MAC entity to be connected to one PDCP entity, may configure multiple RLC entities connected to one SCG MAC entity to be connected to one PDCP entity, or may configure multiple RLC entities connected to different MAC entities to be connected to one PDCP entity, and by doing so, packet repetition can be performed.

[0205] In addition, the BS can indicate which RLC entity among multiple RLC entities is the primary RLC entity or the secondary RLC entity by using a logical channel identifier and a bearer identifier in an RRC message. For example, the cell group configuration information can indicate the configuration information of each RLC entity, and can indicate the bearer identifier and the logical channel identifier corresponding to each RLC entity. In addition, the bearer configuration information can indicate the configuration information of each PDCP entity, and can indicate the bearer identifier corresponding to each PDCP entity, and in the case where multiple RLC entities are configured for the PDCP entity or the bearer identifier, the BS can indicate the primary RLC entity by indicating the logical channel identifier corresponding to the primary RLC entity. Therefore, when the UE receives the RRC message, the UE can configure the PDCP entity according to the bearer identifier, can configure multiple RLC entities to be connected to the PDCP entity, multiple RLC entities correspond to the bearer identifier, and can specify the primary RLC entity and multiple secondary RLC entities.

[0206] As another method, when the BS configures multiple RLC entities connected to one PDCP entity by using an RRC message, the BS can indicate which RLC entity among the multiple RLC entities is the primary RLC entity or the secondary RLC entity by using a logical channel identifier (or SCell identifier) ​​and a bearer identifier. For example, the cell group configuration information can indicate the configuration information of each RLC entity, and can indicate the bearer identifier and the logical channel identifier (or SCell identifier) ​​corresponding to each RLC entity. In addition, the bearer configuration information can indicate the configuration information of each PDCP entity, and can indicate the bearer identifier corresponding to each PDCP entity, and in the case where multiple RLC entities are configured for the PDCP entity or the bearer identifier, the BS can indicate the primary RLC entity by indicating the logical channel identifier (or SCell identifier) ​​corresponding to the primary RLC entity. Therefore, when the UE receives the RRC message, the UE can configure the PDCP entity according to the bearer identifier, can configure multiple RLC entities connected to the PDCP entity, multiple RLC entities correspond to the bearer identifier, and can specify the primary RLC entity and multiple secondary RLC entities by using the logical channel identifier or the SCell identifier.

[0207] As another method, when the BS configures multiple RLC entities connected to one PDCP entity by using an RRC message, the BS can indicate which RLC entity among the multiple RLC entities is a primary RLC entity or a secondary RLC entity by using a new identifier (e.g., an identifier indicating each RLC entity, such as 0, 1, 2, or 3) and a bearer identifier or a logical channel identifier. For example, the cell group configuration information may indicate configuration information of each RLC entity, and may indicate a bearer identifier and a logical channel identifier or a new identifier corresponding to each RLC entity. In addition, the bearer configuration information may indicate configuration information of each PDCP entity, and may indicate a bearer identifier corresponding to each PDCP entity, and in the case where multiple RLC entities are configured for a PDCP entity or a bearer identifier, the BS may indicate the primary RLC entity by indicating a logical channel identifier or a new identifier corresponding to the primary RLC entity. A specific value of the new identifier (e.g., an identifier with the lowest value, i.e., 0) may be defined to indicate a primary RLC entity, and RLC entities with different values ​​may be regarded as secondary RLC entities. Therefore, when the UE receives the RRC message, the UE can configure the PDCP entity according to the bearer identifier, can configure multiple RLC entities connected to the PDCP entity, the multiple RLC entities correspond to the bearer identifier, and can specify the primary RLC entity and multiple secondary RLC entities by using a logical channel identifier or a new identifier.

[0208] As another method, for the packet repetition technology, a primary RLC entity is determined from multiple RLC entities connected to one PDCP entity. At this point, the RLC entity with the lowest identifier value or the highest identifier value (minimum identifier value or maximum identifier value) can be regarded as and therefore configured as a primary RLC entity, and the remaining RLC entities can be regarded as and therefore configured as secondary RLC entities. The lowest identifier value or the highest identifier value (minimum identifier value or maximum identifier value) can be determined by using one of the above methods. The PDCP entity does not apply packet repetition on the PDCP control PDU, and the PDCP control PDU can always be sent to the primary RLC entity. In the case of configuring packet repetition for the PDCP data PDU, the PDCP entity can repeatedly send data to a secondary RLC entity different from the primary RLC entity. The following method for determining the primary RLC entity can be applied to UE and BS.

[0209] When the above process is completed, the UE sends data to the BS or receives data from the BS through the core network (1e-55 and 1e-60). According to an embodiment, the data transmission process can be broadly composed of three operations, namely, RRC connection establishment, security configuration, and DRB configuration. In addition, for some reasons, the BS can send an RRC connection reconfiguration message to newly perform or add configuration for the UE (1e-65). For example, the BS can perform the addition, release, or change of the configuration of the SCell in the CA technology, and can change, release, or add the SCG configuration in the DC technology.

[0210] The process of the BS configuring CA technology or DC technology for the UE can be summarized as follows. After the BS establishes a connection with the BS, the BS configures frequency measurement configuration information for the UE in RRC connection mode, and then the UE performs frequency measurement based on the frequency measurement configuration information and reports the measurement results to the BS. Subsequently, the BS can configure the configuration information about the additional SCell through an RRC message based on the frequency measurement results of the UE to configure the CA technology for the UE, and can activate, deactivate or deactivate the SCell by sending a MAC CE. In addition, the BS can configure the configuration information about the additional secondary cell group based on the frequency measurement results of the UE to configure the DC technology for the UE. In the above, the packet repetition transmission technology can also be configured.

[0211] Figure 1F A protocol entity configured with a packet repetition technique according to an embodiment of the present disclosure is shown.

[0212] exist Figure 1F In the embodiment, the BS can configure the packet repetition technology (1f-01) for the UE by applying the CA technology via an RRC message. In detail, the BS can configure multiple RLC entities 1f-10 and 1f-15 connected to one MAC entity 1f-20, and can configure multiple RLC entities connected to one PDCP entity 1f-05, and perform packet repetition.

[0213] exist Figure 1F In the embodiment, the BS can configure the packet repetition technology for the UE by applying the DC technology via an RRC message. Specifically, the BS can configure multiple RLC entities 1f-30 and 1f-35 connected to different MAC entities 1f-40 and 1f-45 to connect to one PDCP entity 1f-25 and perform packet repetition.

[0214] Figure 1G and 1H A protocol entity for which another packet repetition technique is configured according to an embodiment of the present disclosure is shown.

[0215] In this disclosure, Figure 1G and 1HAs shown, an embodiment is considered in which one primary RLC entity is configured and at most three secondary RLC entities are configured. However, the embodiments of the present disclosure can be widely applied to embodiments in which one or more primary RLC entities or one or more secondary RLC entities are configured.

[0216] In this disclosure, Figure 1H As shown, when multiple RLC entities (or logical channel identifiers) are configured for a UE configured with packet repetition transmission technology, a method for dynamically activating (or indicating the execution of repetition transmission) some RLC entities 1h-05, 1h-20, 1h-25 and 1h-35 among the multiple configured RLC entities or deactivating (or indicating the stop of repetition transmission) some RLC entities 1h-10, 1h-15, 1h-30 and 1h-40 is provided. According to an embodiment of the present disclosure, the main RLC entity may not be deactivated. In the present disclosure, when multiple RLC entities (or logical channel identifiers) are configured for a UE configured with packet repetition transmission technology, an embodiment 1 of dynamically activating (or indicating the execution of repetition transmission) some RLC entities or deactivating (or indicating the stop of repetition transmission) some RLC entities from multiple configured RLC entities is provided. Embodiment 1 is characterized in that, when the DC technology is configured, the MCG BS configures the MCG MAC entity connected to the UE and the activation and deactivation of the RLC entity for which the packet repetition transmission technology is configured, and the SCGBS configures the SCG MAC entity connected to the UE and the activation and deactivation of the RLC entity for which the packet repetition transmission technology is configured.

[0217] Fig. 1I Embodiment 1 of the embodiment of the present disclosure is shown, when multiple RLC entities (or logical channel identifiers) are configured for a UE configured with packet repetition transmission technology, some RLC entities among the multiple configured RLC entities are dynamically activated (or instructed to perform repetition transmission), or some RLC entities are deactivated (or instructed to stop repetition transmission).

[0218] Embodiment 1-1 1i-01 of the present disclosure proposes a method for defining a new MAC CE, and dynamically activating (or instructing to perform repeated transmission) some RLC entities among multiple RLC entities or deactivating (or instructing to stop repeated transmission) some RLC entities based on the MACCE.

[0219] In Embodiment 1-1 1i-01, a separate logical channel identifier may be allocated to the proposed MAC CE, and the L field may not exist in the MAC header of the MAC CE. However, the present disclosure is not limited thereto. In addition, the MAC header and the MAC CE may have a fixed size. However, the present disclosure is not limited thereto. In Embodiment 1-1 1i-01, a bitmap (e.g., D0 to D7) is introduced to the MAC CE, and the bits of the bitmap may be respectively mapped to the bearer identifier value of the bearer in ascending order (or descending order), wherein the packet repetition technology is configured for the bearer. That is, each bit of the bitmap may indicate a bearer for which the packet repetition technology is configured. In addition, four bits corresponding to each bit of the bitmap may be configured (or allocated) to the MAC CE (e.g., L00, L01, L02, and L03 bits corresponding to D0), and thus may indicate multiple RLC entities connected to the bearer for which the packet repetition technology is configured. The four bits corresponding to each bit of the bitmap may be respectively mapped to the logical channel identifier value (or new identifier value) configured for each RLC entity in ascending order (or descending order). As another method, four bits corresponding to each bit of the bitmap may be respectively mapped to all SCell identifier values ​​mapped to the logical channel identifier of the corresponding RLC entity in ascending order (or descending order).

[0220] The bearer identifier may be configured as a natural number between 0 and 31 or 1 and 32 or a binary number corresponding thereto, and the logical channel identifier may be configured as a natural number between 0 and 63 or a binary number corresponding thereto. In the case where D1 is configured as 1 or D0 is configured as 0, the L00, L01, L02, and L03 fields corresponding to D0 may be filled with zeros. Conversely, in the case where D1 is configured as 0 or D0 is configured as 1, the L10, L11, L12, and L13 fields corresponding to D1 may be filled with zeros, and the same may apply to other fields. In the above description, when the L field is 0 (or 1), this may indicate that the secondary RLC entity corresponding thereto will be deactivated, and when the L field is 1 (or 0), this may indicate that the secondary RLC entity corresponding thereto will be activated.

[0221] As another method, in Example 1-1, the bitmap may not be used. Fig. 1IThe MAC CE may have only an L field, and method 1, method 2, method 3, method 4, method 5, method 6, method 7 or method 8 proposed in the present disclosure may be used so that the position of the L field in the MAC CE structure or the sub-index of the L field may be respectively mapped to the bearer identifier value of the RLC entity or bearer in ascending order (or descending order), where the packet repetition technology is configured for the bearer. That is, the position of the L field or the sub-index of the L field may indicate a bearer for which the packet repetition technology is configured. In addition, the four bits corresponding to the bearer may be configured to indicate multiple RLC entities connected to the bearer for which the packet repetition technology is configured. By using method 1, method 2, method 3, method 4, method 5, method 6, method 7 or method 8 proposed in the present disclosure, these four bits may be mapped to the corresponding RLC entity.

[0222] For example, when the L field has "a" and "b" as sub-indexes (e.g., L_(a, b), 1i-01), the sub-index "a" can indicate the a-th bearer in ascending order of the bearer identifier, and the sub-index "b" can indicate each of the three bits, and can indicate the b-th RLC entity (e.g., a secondary RLC entity) by using method 4, method 5, method 6, method 7, or method 8 proposed in the present disclosure. Therefore, when a bearer having 5 as a bearer identifier and a bearer having 8 as a bearer identifier in which the packet repetition technique is configured for the UE, the primary RLC entity and the secondary RLC entity corresponding to the bearer having 5 as a bearer identifier may be mapped to L_(0,0), L_(0,1), L_(0,2), and L_(0,3) and thus may have a value of 0 or 1, the primary RLC entity and the secondary RLC entity corresponding to the bearer having 8 as a bearer identifier may be mapped to L_(1,0), L_(1,1), L_(1,2), and L_(1,3) and thus may have a value of 0 or 1, and all remaining L field values ​​are not used and are filled with a value of 0. A maximum of eight bearers for which packet repetition is configured may be configured.

[0223] The bearer identifier (e.g., 5 bits) can be configured as a natural number between 0 and 31 or 1 and 32 or a binary number corresponding thereto, the logical channel identifier (e.g., 6 bits) can be configured as a natural number between 0 and 63 or a binary number corresponding thereto, and the cell group identifier (e.g., 2 bits) can be configured as a natural number between 0 and 3 or 1 and 4 or a binary number corresponding thereto.

[0224] Embodiment 1-2 1i-02 proposed in the present disclosure may have the same features as embodiment 1-1 1i-01, and a separate logical channel identifier may be assigned to MAC CE. In addition, according to an embodiment of the present disclosure, there may be no L field in the MAC header for MAC CE. However, the present disclosure is not limited to this. In addition, the MAC header may have a fixed size, but the MAC CE may have a flexible size. However, the present disclosure is not limited to this. Compared with embodiment 1-1 1i-01, in embodiment 1-21i-02, four bits corresponding to the bearer identifier that is not configured as 1 but configured as 0 in the bitmap field may be skipped. In detail, when D1 and D0 of the bitmap are configured as 0, 1 bit of the L00, L01, L02, L03, L10, L11, L12, and L13 fields in the L field located adjacent to the bitmap may be skipped. That is, when D2 and D3, D4 and D5, or D6 and D7 are each configured to 0, 1 bit may be skipped, and the L field located adjacent to the bitmap may indicate the 4 bits corresponding to the lowest D field in which 1 is configured. In addition, when D1 is configured to 1 or D0 is configured to 0, the L00, L01, L02, and L03 fields corresponding to D0 may be filled with zeros. Conversely, in the case where D1 is configured to 0 or D0 is configured to 1, the L10, L11, L12, and L13 fields corresponding to D1 may be filled to zero, and the same may be applied to other fields.

[0225] Figure 1J Embodiment 2 of the embodiment of the present disclosure is shown, when multiple RLC entities (or logical channel identifiers) are configured for a UE configured with packet repetition transmission technology, some RLC entities among the multiple configured RLC entities are dynamically activated (or instructed to perform repetition transmission), or some RLC entities are deactivated (or instructed to stop repetition transmission).

[0226] In the present disclosure, when multiple RLC entities (or logical channel identifiers) are configured for a UE configured with a packet repetition transmission technology, an embodiment 2 is provided for dynamically activating (or instructing to perform repetition transmission) some RLC entities or deactivating (or instructing to stop repetition transmission) some RLC entities from multiple configured RLC entities. In embodiment 2, when the DC technology is configured, the MCG BS can configure the activation and deactivation of the RLC entity connected to the MCG MAC entity of the UE and configured with the packet repetition transmission technology, and the SCG BS can configure the activation and deactivation of the RLC entity connected to the SCG MAC entity of the UE and configured with the packet repetition transmission technology.

[0227] Embodiment 2-1 1j-01 of the present disclosure proposes a method for defining a new MAC CE, and dynamically activating (or instructing to perform repeated transmission) some RLC entities among multiple RLC entities or deactivating (or instructing to stop repeated transmission) some RLC entities based on the MACCE.

[0228] In Embodiment 2-1 1j-01, a separate logical channel identifier (or a new identifier) ​​may be allocated to the proposed MAC CE, and the L field may not exist in the MAC header of the MAC CE. However, the present disclosure is not limited thereto. In addition, the MAC header and the MAC CE may have a fixed size. However, the present disclosure is not limited thereto. In Embodiment 2-1 1j-01, a bitmap (e.g., D0 to D7) is introduced to the MAC CE, and the bits of the bitmap may be respectively mapped to the bearer identifier values ​​of the bearers in ascending (or descending) order, wherein the packet repetition technology is configured for the bearers. That is, each bit of the bitmap may indicate a bearer for which the packet repetition technology is configured. In addition, three bits corresponding to each bit of the bitmap may be configured (or allocated) to the MAC CE (e.g., L00, L01, and L02 corresponding to D0), and thus may indicate multiple secondary RLC entities connected to the bearer for which the packet repetition technology is configured. Because the primary RLC entity may not be deactivated, the MAC CE may indicate the activation or deactivation of only the secondary RLC entity. The three bits of the MAC CE may be respectively mapped to the logical channel identifier value (or new identifier value) configured for the corresponding secondary RLC entity in ascending order (or descending order). As another method, the three bits may be respectively mapped to the SCell identifier value of the logical channel identifier mapped to each secondary RLC entity in ascending order (or descending order).

[0229] The bearer identifier can be configured as a natural number between 0 and 31 or 1 and 32 or a binary number corresponding thereto, and the logical channel identifier can be configured as a natural number between 0 and 63 or a binary number corresponding thereto. When D1 is configured as 1 or D0 is configured as 0, the L00, L01, and L02 fields corresponding to D0 can be filled with zero. On the contrary, when D1 is configured as 0 or D0 is configured as 1, the L10, L11, and L12 fields corresponding to D1 can be filled with zero, and the same can be applied to other fields. In addition, the R field cannot be used as a reserved field. In the above description, when the L field is 0 (or 1), this can indicate that the corresponding secondary RLC entity will be deactivated, and when the L field is 1 (or 0), this can indicate that the corresponding secondary RLC entity will be activated.

[0230] As another method, in embodiment 2-1, a bitmap may not be used, only the L field may be included in 1j-01, and method 1, method 2, method 3, method 4, method 5, method 6, method 7 or method 8 proposed in the present disclosure may be used, so that the position of the L field in the MAC CE structure or the sub-index of the L field can be respectively mapped to the RLC entity or the bearer identifier value of the bearer in ascending order (or descending order), wherein the packet repetition technology is configured for the bearer. That is, the position of the L field or the sub-index of the L field can indicate a bearer for which the packet repetition technology is configured. In addition, the three bits corresponding to the bearer can be configured to indicate multiple secondary RLC entities connected to the bearer for which the packet repetition technology is configured. By using method 4, method 5, method 6, method 7 or method 8 proposed in the present disclosure, the three bits can be mapped to the corresponding RLC entity. According to an embodiment of the present disclosure, three bits can indicate multiple secondary RLC entities connected to the bearer for which the packet repetition technology is configured. Because the primary RLC entity may not be deactivated, the BS may only indicate the activation or deactivation of the secondary RLC entity.

[0231] For example, when the L field has "a" and "b" as sub-indexes (e.g., L_(a, b), 1j-01), the sub-index "a" can indicate the a-th bearer in ascending order of the bearer identifiers, and the sub-index "b" can indicate each of the three bits, and can indicate the b-th RLC entity (e.g., a secondary RLC entity) by using method 4, method 5, method 6, method 7, or method 8 proposed in the present disclosure. Therefore, when a bearer having 5 as a bearer identifier and a bearer having 8 as a bearer identifier for which a packet repetition technique is configured for the UE are configured, the primary RLC entity and the secondary RLC entity corresponding to the bearer having 5 as a bearer identifier may be mapped to L_(0,0), L_(0,1), and L_(0,2) and thus may have a value of 0 or 1, the primary RLC entity and the secondary RLC entity corresponding to the bearer having 8 as a bearer identifier may be mapped to L_(1,0), L_(1,1), and L_(1,2) and thus may have a value of 0 or 1, and all remaining L field values ​​are not used and are filled with a value of 0. A maximum of eight bearers for which packet repetition is configured may be configured.

[0232] The bearer identifier (e.g., 5 bits) can be configured as a natural number between 0 and 31 or 1 and 32 or a binary number corresponding thereto, the logical channel identifier (e.g., 6 bits) can be configured as a natural number between 0 and 63 or a binary number corresponding thereto, and the cell group identifier (e.g., 2 bits) can be configured as a natural number between 0 and 3 or 1 and 4 or a binary number corresponding thereto.

[0233] Embodiment 2-2 1j-02 proposed in the present disclosure may have the same features as embodiment 2-1 1j-01, and a separate logical channel identifier (or a new identifier) ​​may be assigned to the MAC CE. In addition, according to an embodiment of the present disclosure, the L field may not exist in the MAC header for the MAC CE. However, the present disclosure is not limited to this. In addition, the MAC header may have a fixed size, but the MAC CE may have a variable size. However, the present disclosure is not limited to this. Compared with embodiment 2-1 1j-01, in embodiment 2-2 1j-02, four bits of the reserved bits corresponding to the bearer identifier that is not configured as 1 but configured as 0 in the bitmap field may be skipped. In detail, when D1 and D0 of the bitmap are configured to 0, 1 bit of the L00, L01, L02, R, L10, L11, L12 and R fields in the L field located adjacent to the bitmap may be skipped. That is, when D2 and D3, D4 and D5, or D6 and D7 are each configured to 0, 1 bit can be skipped, and the R field or L field located next to the bitmap can indicate the four bits corresponding to the lowest D field for which 1 is configured. In addition, when D1 is configured to 1 or D0 is configured to 0, the L00, L01, and L02 fields corresponding to D0 can be filled with zeros. On the contrary, when D1 is configured to 0 or D0 is configured to 1, the L10, L11, and L12 fields corresponding to D1 can be filled to zero, and the same can be applied to other fields. In addition, the R field cannot be used as a reserved field.

[0234] Figure 1K Embodiment 3 of the embodiment of the present disclosure is shown, when multiple RLC entities (or logical channel identifiers) (or new identifiers) are configured for a UE configured with packet repetition transmission technology, some RLC entities among the multiple configured RLC entities are dynamically activated (or instructed to perform repetition transmission), or some RLC entities are deactivated (or instructed to stop repetition transmission).

[0235] In the present disclosure, when multiple RLC entities (or logical channel identifiers) are configured for a UE configured with a packet repetition transmission technology, an embodiment 3 is provided for dynamically activating (or instructing to perform repetition transmission) some RLC entities or deactivating (or instructing to stop repetition transmission) some RLC entities from multiple configured RLC entities. In embodiment 3, when the DC technology is configured, the MCG BS or SCG BS can configure the activation and deactivation of the RLC entity connected to the MCG MAC entity of the UE and configured with the packet repetition transmission technology, and the MCG BS or SCG BS can configure the activation and deactivation of the RLC entity connected to the SCG MAC entity of the UE and configured with the packet repetition transmission technology.

[0236] Embodiment 3-1 1k-01 of the present disclosure proposes a method for defining a new MAC CE, and dynamically activating (or instructing to perform repeated transmission) some RLC entities among multiple RLC entities or deactivating (or instructing to stop repeated transmission) some RLC entities based on the MACCE.

[0237] In Example 3-1 1k-01, a separate logical channel identifier may be allocated to the proposed MAC CE, and the L field may not exist in the MAC header of the MAC CE. However, the present disclosure is not limited to this. In addition, the MAC header and the MAC CE may have a fixed size. However, the present disclosure is not limited to this. In Example 3-1 1k-01, a bitmap (e.g., D0 to D7) is introduced to the MAC CE, and the bits of the bitmap may be mapped to the bearer identifier values ​​of the bearers in ascending (or descending) order, respectively, where the packet repetition technology is configured for the bearers. That is, each bit of the bitmap may indicate a bearer for which the packet repetition technology is configured. In addition, three bits corresponding to each bit of the bitmap may be configured (or allocated) to the MAC CE (e.g., L00, L01, and L02 corresponding to D0), and thus may indicate multiple secondary RLC entities connected to the bearer for which the packet repetition technology is configured. Because the primary RLC entity may not be deactivated, the MAC CE may indicate the activation or deactivation of only the secondary RLC entity. The three bits of the MAC CE may be respectively mapped to the logical channel identifier value (or new identifier value) configured for the corresponding secondary RLC entity in ascending order (or descending order). As another method, the three bits may be respectively mapped to the SCell identifier value of the logical channel identifier mapped to each secondary RLC entity in ascending order (or descending order).

[0238] The bearer identifier may be configured as a natural number between 0 and 31 or 1 and 32 or a binary number corresponding thereto, and the logical channel identifier (or a new identifier value) may be configured as a natural number between 0 and 63 or a binary number corresponding thereto. In the case where D1 is configured as 1 or D0 is configured as 0, the L00, L01, and L02 fields corresponding to D0 may be filled with zeros. Conversely, in the case where D1 is configured as 0 or D0 is configured as 1, the L10, L11, and L12 fields corresponding to D1 may be filled with zeros, and the same may be applied to other fields.

[0239] In addition, the G field can indicate the cell group to which the logical channel identifier (or a new identifier value) is connected. For example, when the G field is connected to the MCG, the value of the G field may be 0 (or 1), and when the G field is connected to the SCG, the value of the G field may be 1 (or 0). Therefore, the MCG BS and the SCG BS can not only activate and deactivate the RLC entity connected to the MCG MAC entity of the UE, but also activate and deactivate the RLC entity connected to the SCG MAC entity. In the above description, when the L field is 0 (or 1), this may indicate that the secondary RLC entity corresponding thereto will be deactivated, and when the L field is 1 (or 0), this may indicate that the secondary RLC entity corresponding thereto will be activated.

[0240] As another method, in Embodiment 3-1, a bitmap may not be used, only the L field may be included in 1k-01, and Method 1, Method 2, Method 3, Method 4, Method 5, Method 6, Method 7 or Method 8 proposed in the present disclosure may be used, so that the position of the L field in the MAC CE structure or the sub-index of the L field may be respectively mapped to the bearer identifier value of the RLC entity or the bearer in ascending order (or descending order), wherein the packet repetition technology is configured for the bearer. That is, the position of the L field or the sub-index of the L field may indicate a bearer for which the packet repetition technology is configured. In addition, the three bits corresponding to the bearer may be configured to indicate a plurality of secondary RLC entities connected to the bearer for which the packet repetition technology is configured. By using Method 4, Method 5, Method 6, Method 7 or Method 8 proposed in the present disclosure, the three bits may be mapped to the corresponding RLC entity. According to an embodiment of the present disclosure, the three bits may indicate a plurality of secondary RLC entities connected to the bearer for which the packet repetition technology is configured. Because the primary RLC entity may not be deactivated, the BS may indicate the activation or deactivation of only the secondary RLC entity.

[0241] For example, when the L field has "a" and "b" as sub-indexes (e.g., L_(a, b), 1k-01), the sub-index "a" can indicate the a-th bearer in ascending order of the bearer identifiers, and the sub-index "b" can indicate each of the three bits, and can indicate the b-th RLC entity (e.g., a secondary RLC entity) by using method 4, method 5, method 6, method 7, or method 8 proposed in the present disclosure. Therefore, when a bearer having 5 as a bearer identifier and a bearer having 8 as a bearer identifier in which the packet repetition technique is configured for the UE, the primary RLC entity and the secondary RLC entity corresponding to the bearer having 5 as a bearer identifier may be mapped to L_(0,0), L_(0,1), and L_(0,2) and thus may have a value of 0 or 1, the primary RLC entity and the secondary RLC entity corresponding to the bearer having 8 as a bearer identifier may be mapped to L_(1,0), L_(1,1), and L_(1,2) and thus may have a value of 0 or 1, and all remaining L field values ​​are not used and are filled with a value of 0. A maximum of eight bearers for which packet repetition is configured may be configured.

[0242] The bearer identifier (e.g., 5 bits) can be configured as a natural number between 0 and 31 or 1 and 32 or a binary number corresponding thereto, the logical channel identifier (e.g., 6 bits) can be configured as a natural number between 0 and 63 or a binary number corresponding thereto, and the cell group identifier (e.g., 2 bits) can be configured as a natural number between 0 and 3 or 1 and 4 or a binary number corresponding thereto.

[0243] Embodiment 3-2 1k-02 proposed in the present disclosure may have the same features as embodiment 3-1 1k-01, and a separate logical channel identifier may be allocated to the MAC CE. In addition, according to an embodiment of the present disclosure, the L field may not exist in the MAC header for the MAC CE. However, the present disclosure is not limited to this. In addition, the MAC header may have a fixed size, but the MAC CE may have a variable size. Compared with embodiment 3-1 1k-01, in embodiment 3-2 1k-02, four bits of the G field corresponding to the bearer identifier that is not configured as 1 but configured as 0 in the bitmap field may be skipped. In detail, when D1 and D0 of the bitmap are configured to 0, 1 bit of the L00, L01, L02, R, L10, L11, L12, and R fields in the L field located adjacent to the bitmap may be skipped. That is, when D2 and D3, D4 and D5, or D6 and D7 are each configured to 0, 1 bit may be skipped, and the G field or L field located adjacent to the bitmap may indicate the four bits corresponding to the lowest D field for which 1 is configured. In addition, when D1 is configured to 1 or D0 is configured to 0, the L00, L01, and L02 fields corresponding to D0 may be filled with zeros. Conversely, in the case where D1 is configured to 0 or D0 is configured to 1, the L10, L11, and L12 fields corresponding to D1 may be filled to zero, and the same may be applied to other fields.

[0244] Figure 1L Embodiment 4 of the embodiment of the present disclosure is shown, when multiple RLC entities (or logical channel identifiers) (or new identifiers) are configured for a UE configured with packet repetition transmission technology, some RLC entities among the multiple configured RLC entities are dynamically activated (or instructed to perform repetition transmission), or some RLC entities are deactivated (or instructed to stop repetition transmission).

[0245] In the present disclosure, when multiple RLC entities (or logical channel identifiers) are configured for a UE configured with a packet repetition transmission technology, an embodiment 4 is provided for dynamically activating (or instructing to perform repetition transmission) some RLC entities or deactivating (or instructing to stop repetition transmission) some RLC entities from multiple configured RLC entities. In embodiment 4, when the DC technology is configured, the MCG BS can configure the activation and deactivation of the RLC entity of the MCG MAC entity connected to the UE and for which the packet repetition transmission technology is configured, and the SCG BS can configure the activation and deactivation of the RLC entity of the SCG MAC entity connected to the UE and for which the packet repetition transmission technology is configured.

[0246] Embodiment 4-1 11-01 of the present disclosure proposes a method for defining a new MAC CE, and dynamically activating (or instructing to perform repeated transmission) some RLC entities among multiple RLC entities or deactivating (or instructing to stop repeated transmission) some RLC entities based on the MACCE.

[0247] In Example 4-1 11-01, a separate logical channel identifier may be allocated to the proposed MAC CE, and the L field may not exist in the MAC header of the MAC CE. However, the present disclosure is not limited to this. In addition, the MAC header and the MAC CE may have a fixed size. However, the present disclosure is not limited to this. In Example 4-1 11-01, a bitmap (e.g., D0 to D7) is introduced to the MAC CE, and the bits of the bitmap may be mapped to the bearer identifier values ​​of the bearers in ascending (or descending) order, respectively, where the packet repetition technology is configured for the bearers. That is, each bit of the bitmap may indicate a bearer for which the packet repetition technology is configured. In addition, three bits corresponding to each bit of the bitmap may be configured (or allocated) (e.g., L00, L01, and L01 corresponding to D0), and thus may indicate multiple secondary RLC entities connected to the bearer for which the packet repetition technology is configured. Because the primary RLC entity may not be deactivated, the MAC CE may only indicate the activation or deactivation of the secondary RLC entity. The three bits may be respectively mapped to a logical channel identifier value (or a new identifier value), which is configured for the corresponding secondary RLC entity in ascending order (or descending order). As another method, the three bits may be respectively mapped to the SCell identifier value of the logical channel identifier mapped to each secondary RLC entity in ascending order (or descending order).

[0248] The bearer identifier may be configured as a natural number between 0 and 31 or 1 and 32 or a binary number corresponding thereto, and the logical channel identifier (or a new identifier value) may be configured as a natural number between 0 and 63 or a binary number corresponding thereto. In the case where D1 is configured as 1 or D0 is configured as 0, the L00, L01, and L02 fields corresponding to D0 may be filled with zeros. Conversely, in the case where D1 is configured as 0 or D0 is configured as 1, the L10, L11, and L12 fields corresponding to D1 may be filled with zeros, and the same may be applied to other fields.

[0249] In addition, the P field is a field used to dynamically indicate that an existing primary RLC entity is changed to a secondary RLC entity, the existing primary RLC entity is connected to a bearer for which a packet repetition transmission technology is configured and corresponds to the D field, and another secondary RLC entity is changed to a new primary RLC entity. For example, when the P field is configured to 1, the MAC CE may not indicate activation and deactivation of an RLC entity connected to a bearer for which a packet repetition transmission technology is configured and corresponds to the D field, but may indicate configuration or change of a new primary RLC entity for the bearer. That is, in the case where the P field is configured to 1 and the L field of the three L fields corresponding to the D field is configured to 1, this situation may mean that the secondary RLC entity corresponding to the L field configured to 1 will be configured as a new primary RLC entity, and the existing primary RLC entity will be changed to a secondary RLC entity.

[0250] In addition, considering the logical channel identifier (or new identifier value) of the secondary RLC entity that is newly changed due to the P field, the L field corresponding to the D field can be mapped again in ascending order (or descending order). When the P field is configured to 0, the MAC CE can indicate the activation and deactivation of the RLC entity connected to the bearer for which the packet repetition transmission technology is configured and corresponding to the D field. In addition, the MAC CE can indicate that when the L field is 0 (or 1), the secondary RLC entity corresponding thereto will be deactivated, and when the L field is 1 (or 0), the secondary RLC entity corresponding thereto will be activated.

[0251] As another method, in embodiment 4-1, a bitmap may not be used, only the L field may be included in 11-01, and method 1, method 2, method 3, method 4, method 5, method 6, method 7 or method 8 proposed in the present disclosure may be used, so that the position of the L field in the MAC CE structure or the sub-index of the L field may be respectively mapped to the RLC entity or the bearer identifier value of the bearer in ascending order (or descending order), wherein the packet repetition technology is configured for the bearer. That is, the position of the L field or the sub-index of the L field may indicate a bearer for which the packet repetition technology is configured. In addition, the three bits corresponding to the bearer may be configured to indicate multiple secondary RLC entities connected to the bearer for which the packet repetition technology is configured. By using method 4, method 5, method 6, method 7 or method 8 proposed in the present disclosure, the three bits may be mapped to the corresponding RLC entity. According to an embodiment of the present disclosure, three bits may indicate multiple secondary RLC entities connected to the bearer for which the packet repetition technology is configured. Because the primary RLC entity may not be deactivated, the BS may only indicate the activation or deactivation of the secondary RLC entity.

[0252] For example, when the L field has "a" and "b" as sub-indexes (e.g., L_(a, b), 1l-01), the sub-index "a" can indicate the ath bearer in ascending order of the bearer identifiers, and the sub-index "b" can indicate each of the three bits, and can indicate the bth RLC entity (e.g., a secondary RLC entity) by using method 4, method 5, method 6, method 7, or method 8 proposed in the present disclosure. Therefore, when a bearer having 5 as a bearer identifier and a bearer having 8 as a bearer identifier for which the packet repetition technique is configured for the UE, the primary RLC entity and the secondary RLC entity corresponding to the bearer having 5 as a bearer identifier may be mapped to L_(0,0), L_(0,1) and L_(0,2) and thus may have a value of 0 or 1, the primary RLC entity and the secondary RLC entity corresponding to the bearer having 8 as a bearer identifier may be mapped to L_(1,0), L_(1,1) and L_(1,2) and thus may have a value of 0 or 1, and all remaining L field values ​​are not used and are filled with a value of 0. A maximum of eight bearers for which packet repetition is configured may be configured.

[0253] The bearer identifier (e.g., 5 bits) can be configured as a natural number between 0 and 31 or 1 and 32 or a binary number corresponding thereto, the logical channel identifier (e.g., 6 bits) can be configured as a natural number between 0 and 63 or a binary number corresponding thereto, and the cell group identifier (e.g., 2 bits) can be configured as a natural number between 0 and 3 or 1 and 4 or a binary number corresponding thereto.

[0254] Embodiment 4-2 11-02 proposed in the present disclosure may have the same features as embodiment 4-1 11-01, and a separate logical channel identifier may be allocated to the MAC CE. In addition, according to an embodiment of the present disclosure, the L field may not exist in the MAC header for the MAC CE. However, the present disclosure is not limited to this. In addition, the MAC header may have a fixed size, but the MAC CE may have a variable size. Compared with embodiment 4-1 11-01, in embodiment 4-2 11-02, four bits of the reserved bits corresponding to the bearer identifier that is not configured as 1 but configured as 0 in the bitmap field may be skipped. In detail, when D1 and D0 of the bitmap are configured as 0, 1 bit of the L00, L01, L02, P, L10, L11, L12 and P fields in the L field located next to the bitmap may be skipped. That is, when D2 and D3, D4 and D5, or D6 and D7 are each configured to 0, 1 bit can be skipped, and the G field or L field located adjacent to the bitmap can indicate the four bits corresponding to the lowest D field for which 1 is configured. In addition, when D1 is configured to 1 or D0 is configured to 0, the L00, L01, and L02 fields corresponding to D0 can be filled with zero. On the contrary, in the case where D1 is configured to 0 or D0 is configured to 1, the L10, L11, and L12 fields corresponding to D1 can be filled to zero, and the same can be applied to other fields. In the above description, when the L field is 0 (or 1), this can indicate that the secondary RLC entity corresponding thereto will be deactivated, and when the L field is 1 (or 0), this can indicate that the secondary RLC entity corresponding thereto will be activated.

[0255] Figure 1M Embodiment 5 of the embodiment of the present disclosure is shown, when multiple RLC entities (or logical channel identifiers) (or new identifier values) are configured for a UE configured with packet repetition transmission technology, some RLC entities are dynamically activated (or instructed to perform repetition transmission) or some RLC entities are deactivated (or instructed to stop repetition transmission) from multiple configured RLC entities.

[0256] In the present disclosure, when multiple RLC entities (or logical channel identifiers) (or new identifier values) are configured for a UE configured with a packet repetition transmission technology, an embodiment 5 is provided for dynamically activating (or instructing to perform repetition transmission) some RLC entities or deactivating (or instructing to stop repetition transmission) some RLC entities from multiple configured RLC entities. In embodiment 5, when the DC technology is configured, the MCG BS may configure the activation and deactivation of the RLC entity connected to the MCG MAC entity of the UE and configured with the packet repetition transmission technology, and the SCG BS may configure the activation and deactivation of the RLC entity connected to the SCG MAC entity of the UE and configured with the packet repetition transmission technology. Alternatively, the BS may not indicate the activation and deactivation of multiple RLC entities connected to multiple bearers for which the packet repetition transmission technology is configured, but may indicate the activation and deactivation of multiple RLC entities connected to the bearers for which the packet repetition transmission technology is configured according to each bearer.

[0257] Embodiment 5-1 1m-01 of the present disclosure proposes a method for defining a new MAC CE, and dynamically activating (or instructing to perform repeated transmission) some RLC entities among multiple RLC entities or deactivating (or instructing to stop repeated transmission) some RLC entities based on the MACCE.

[0258] In Example 5-1 1m-01, a separate logical channel identifier may be allocated to the proposed MAC CE, and the L field may not exist in the MAC header of the MAC CE. However, the present disclosure is not limited to this. In addition, the MAC header and the MAC CE may have a fixed size. However, the present disclosure is not limited to this. In Example 5-1 1m-01, the maximum number of configurable packet repetition techniques is limited to, for example, 8, and the bearer identifier values ​​of the bearers for which the packet repetition transmission technique is configured may be mapped to 0 to 7 in ascending (or descending) order, respectively. In addition, a 3-bit bearer index field (DRB index) is defined and indicates a value of 0 to 7, thereby indicating the bearer for which the packet repetition transmission technique is configured. In addition, the four bits corresponding to the bearer index field (e.g., L1, L2, L3, and L4) may be configured to indicate multiple RLC entities connected to the bearer for which the packet repetition technique is configured. These four bits may be respectively mapped to logical channel identifier values ​​(or new identifier values), which are configured for the respective RLC entities in ascending (or descending) order. As another method, the four bits may be respectively mapped to the SCell identifier value mapped to the logical channel identifier of the corresponding RLC entity in ascending order (or descending order). In the above description, when the L field is 0 (or 1), this may indicate that the secondary RLC entity corresponding thereto will be deactivated, and when the L field is 1 (or 0), this may indicate that the secondary RLC entity corresponding thereto will be activated.

[0259] Embodiment 5-2 1m-02 of the present disclosure proposes a method for defining a new MAC CE, and dynamically activating (or instructing to perform repeated transmission) some RLC entities among multiple RLC entities or deactivating (or instructing to stop repeated transmission) some RLC entities based on the MACCE.

[0260] In Example 5-2 1m-02, a separate logical channel identifier may be allocated to the proposed MAC CE, and the L field may not exist in the MAC header of the MAC CE. However, the present disclosure is not limited to this. In addition, the MAC header and the MAC CE may have a fixed size. However, the present disclosure is not limited to this. In Example 5-2 1m-02, the maximum number of configurable packet repetition techniques is limited to 8, and the bearer identifier values ​​of the bearers for which the packet repetition transmission technique is configured may be mapped to 0 to 7 in ascending (or descending) order, respectively. In addition, a 3-bit bearer index field (DRB index) is defined and indicates a value of 0 to 7, thereby indicating the bearer for which the packet repetition transmission technique is configured. In addition, the four bits corresponding to the bearer index field (e.g., L1, L2, L3, and L4) may be configured to indicate multiple RLC entities connected to the bearer for which the packet repetition technique is configured. These four bits may be respectively mapped to logical channel identifier values ​​(or new identifier values), which are configured for the respective RLC entities in ascending (or descending) order. As another method, the four bits may be respectively mapped to SCell identifier values ​​mapped to the logical channel identifier of the corresponding RLC entity in ascending order (or descending order).

[0261] In addition, the P field may be defined and used as in Example 4-1 11-01. The P field is a field used to dynamically indicate that an existing primary RLC entity is changed to a secondary RLC entity, the existing primary RLC entity is connected to a bearer for which a packet repetition transmission technology is configured and corresponds to a bearer index field, and another secondary RLC entity is changed to a new primary RLC entity. For example, when the P field is configured to 1, the MAC CE may not indicate the activation and deactivation of the RLC entity connected to the bearer for which a packet repetition transmission technology is configured and corresponds to the bearer index field, but may indicate that a new primary RLC entity is configured or changed for the bearer. That is, in the case where the P field is configured to 1 and the L field of the four L fields corresponding to the bearer index field is configured to 1, this situation may mean that the secondary RLC entity corresponding to the L field configured to 1 will be configured as a new primary RLC entity, and the existing primary RLC entity will be changed to a secondary RLC entity. In addition, considering the logical channel identifier (or new identifier value) of the secondary RLC entity that is newly changed due to the P field, the L field corresponding to the bearer index field can be mapped again in ascending order (or descending order). When the P field is configured to 0, the MACCE can indicate the activation and deactivation of the RLC entity connected to the bearer for which the packet repetition transmission technology is configured and which corresponds to the bearer index field. When the L field is 0 (or 1), this can indicate that the secondary RLC entity corresponding to it will be deactivated, and when the L field is 1 (or 0), this can indicate that the secondary RLC entity corresponding to it will be activated.

[0262] Embodiment 5-3 1m-03 of the present disclosure proposes a method for defining a new MAC CE, and dynamically activating (or instructing to perform repeated transmission) some RLC entities among multiple RLC entities or deactivating (or instructing to stop repeated transmission) some RLC entities based on the MACCE.

[0263] In Example 5-3 1m-03, a separate logical channel identifier may be allocated to the proposed MAC CE, and the L field may not exist in the MAC header of the MAC CE. However, the present disclosure is not limited to this. In addition, the MAC header and the MAC CE may have a fixed size. However, the present disclosure is not limited to this. In Example 5-3 1m-03, the maximum number of configurable packet repetition techniques is limited to 8, and the bearer identifier values ​​of the bearers for which the packet repetition transmission technique is configured may be mapped to 0 to 7 in ascending (or descending) order, respectively. In addition, a 3-bit bearer index field (DRB index) is defined and indicates a value of 0 to 7, thereby indicating the bearer for which the packet repetition transmission technique is configured. In addition, the three bits corresponding to the bearer index field (e.g., L1, L2, and L3) may be configured to indicate multiple secondary RLC entities connected to the bearer for which the packet repetition technique is configured. Because the primary RLC entity may not be deactivated, the MAC CE may only indicate the activation or deactivation of the secondary RLC entity. The three bits may be respectively mapped to a logical channel identifier value (or a new identifier value), which is configured for the corresponding secondary RLC entity in ascending order (or descending order). As another method, the three bits may be respectively mapped to the SCell identifier value of the logical channel identifier mapped to each secondary RLC entity in ascending order (or descending order).

[0264] In addition, the P field may be defined and used as in Example 4-1 11-01. The P field is a field used to dynamically indicate that an existing primary RLC entity is changed to a secondary RLC entity, the existing primary RLC entity is connected to a bearer for which a packet repetition transmission technology is configured and corresponds to a bearer index field, and indicates that another secondary RLC entity is changed to a new primary RLC entity. For example, when the P field is configured to 1, the MAC CE may not indicate the activation and deactivation of the RLC entity connected to the bearer for which a packet repetition transmission technology is configured and corresponds to the bearer index field, but may indicate that a new primary RLC entity is configured or changed for the bearer. That is, in the case where the P field is configured to 1 and the L field of the four L fields corresponding to the bearer index field is configured to 1, this situation may mean that the secondary RLC entity corresponding to the L field configured to 1 will be configured as a new primary RLC entity, and the existing primary RLC entity will be changed to a secondary RLC entity. In addition, considering the logical channel identifier (or new identifier value) of the secondary RLC entity that is newly changed due to the P field, the L field corresponding to the bearer index field can be mapped again in ascending order (or descending order). When the P field is configured to 0, the MAC CE can indicate the activation and deactivation of the RLC entity connected to the bearer for which the packet repetition transmission technology is configured and which corresponds to the bearer index field. When the L field is 0 (or 1), this can indicate that the secondary RLC entity corresponding to it will be deactivated, and when the L field is 1 (or 0), this can indicate that the secondary RLC entity corresponding to it will be activated.

[0265] Embodiment 5-4 1m-04 of the present disclosure proposes a method for defining a new MAC CE, and dynamically activating (or instructing to perform repeated transmission) some RLC entities among multiple RLC entities or deactivating (or instructing to stop repeated transmission) some RLC entities based on the MACCE.

[0266] In Example 5-4 1m-04, a separate logical channel identifier may be allocated to the proposed MAC CE, and the L field may not exist in the MAC header of the MAC CE. However, the present disclosure is not limited to this. In addition, the MAC header and the MAC CE may have a fixed size. However, the present disclosure is not limited to this. In Example 5-4 1m-04, the bearer identifier (DRB ID) field configured with the packet repetition transmission technology may be defined to directly indicate the bearer configured with the packet repetition transmission technology. In addition, the three bits corresponding to the bearer identifier field (e.g., L1, L2, and L3) may be configured to indicate multiple secondary RLC entities connected to the bearer for which the packet repetition technology is configured. Because the primary RLC entity may not be deactivated, the MACCE may only indicate the activation or deactivation of the secondary RLC entity. The three bits may be respectively mapped to logical channel identifier values ​​(or new identifier values), which are configured in ascending order (or descending order) for the corresponding secondary RLC entity. As another method, the three bits may be respectively mapped in ascending order (or descending order) to the SCell identifier value of the logical channel identifier mapped to each secondary RLC entity. When the L field is 0 (or 1), this may indicate that the secondary RLC entity corresponding thereto is to be deactivated, and when the L field is 1 (or 0), this may indicate that the secondary RLC entity corresponding thereto is to be activated.

[0267] The BS or UE in Embodiment 5-1, Embodiment 5-2, Embodiment 5-3 or Embodiment 5-4 has the efficient MAC CE proposed in the present disclosure, and can map each bit to the primary RLC entity or the secondary RLC entity. In addition, the BS or UE can map each RLC entity to a bit by using Method 1, Method 2, Method 3, Method 4, Method 5, Method 6 or Method 6 proposed in the present disclosure until each RLC entity is activated or deactivated.

[0268] According to Example 5-1, Example 5-2, Example 5-3 or Example 5-4 of the efficient MAC CE proposed in the present disclosure, the MAC CE can be composed of a MAC header and multiple bits, each bit indicating bearer indication information and an L field, and can jointly indicate the activation or deactivation of multiple bearer RLC entities at one time.

[0269] Figure 1N Embodiment 6 of the embodiment of the present disclosure is shown, when multiple RLC entities (or logical channel identifiers) (or new identifier values) are configured for a UE configured with packet repetition transmission technology, some RLC entities among the multiple configured RLC entities are dynamically activated (or instructed to perform repetition transmission), or some RLC entities are deactivated (or instructed to stop repetition transmission).

[0270] Embodiment 6 (1n-01 and 1n-02) of the present disclosure proposes a method of defining a new field in a MAC header, and dynamically activating (or instructing to perform repeated transmission) some RLC entities among multiple configured RLC entities based on MAC CE, or deactivating (or instructing to stop repeated transmission) some RLC entities.

[0271] In Example 6 (1n-01 and 1n-02), when the DC technology is configured, the MCG BS may configure the MCG MAC entity connected to the UE and the activation and deactivation of the RLC entity for which the packet repetition transmission technology is configured, and the SCG BS may configure the SCG MAC entity connected to the UE and the activation and deactivation of the RLC entity for which the packet repetition transmission technology is configured. In addition, the BS may not indicate the activation and deactivation of multiple RLC entities connected to multiple bearers configured with the packet repetition transmission technology, but may indicate the activation and deactivation of multiple RLC entities connected to bearers configured with the packet repetition transmission technology according to each logical channel (or each new identifier).

[0272] The principles of Embodiment 1 (1i-01 and 1i-02), Embodiment 2 (1j-01 and 1j-02), Embodiment 3 (1k-01 and 1k-02), Embodiment 4 (1l-01 and 1l-02) or Embodiment 5 (1m-01, 1m-02, 1m-03 and 1m-04) may be applied to Embodiment 6 of the present disclosure, and the P field or the G field proposed in the aforementioned embodiments may be indicated in the MAC header. In addition, since the MAC header includes a logical channel identifier, a 1-bit indicator (A / D) may be defined in the MAC header to indicate whether to activate and deactivate the RLC entity corresponding to the logical channel.

[0273] Fig.1O Embodiment 7 according to the present disclosure is shown, in which when multiple RLC entities (or logical channel identifiers) (or new identifier values) are configured for a UE configured with packet repetition transmission technology, some RLC entities are dynamically activated (or instructed to perform repetition transmission) or some RLC entities are deactivated (or instructed to stop repetition transmission) from the multiple configured RLC entities.

[0274] As described below, embodiment 7 (1o-01, 1o-02 and 1o-03) according to the present disclosure is provided, wherein when multiple RLC entities (or logical channel identifiers) are configured for a UE configured with packet repetition transmission technology, some of the multiple configured RLC entities are dynamically activated (or instructed to perform repetition transmission) or some RLC entities are deactivated (or instructed to stop repetition transmission). In embodiment 7 (1o-01, 1o-02 and 1o-03), when DC technology is configured, the MCG BS may configure the activation and deactivation of the RLC entity connected to the UE and configured with the packet repetition transmission technology, and the SCGBS may configure the activation and deactivation of the RLC entity connected to the UE and configured with the packet repetition transmission technology. Alternatively, the MCG BS or the SCG BS may indicate the MCG MAC entity or the SCG MAC entity by defining the G field. Furthermore, activation and deactivation of a plurality of RLC entities connected to a plurality of bearers configured with a packet repetition transmission technique may be performed once with respect to an RLC entity configured with a packet repetition transmission technique and connected to a MAC entity.

[0275] Embodiment 7-1 of the present disclosure proposes a method for defining a new MAC CE, and dynamically activating (or instructing to perform repeated transmission) some RLC entities among multiple RLC entities or deactivating (or instructing to stop repeated transmission) some RLC entities based on the MAC CE.

[0276] In Example 7-1, a separate logical channel identifier may be allocated to the proposed MAC CE, and the L field may not exist in the MAC header of the MAC CE. However, the present disclosure is not limited to this. In addition, the MAC header and the MAC CE may have a fixed size. However, the present disclosure is not limited to this. In Example 7-1, the bearer configured with the packet repetition technology may not be indicated. That is, multiple L bits (for example, 16) may be defined, and multiple L fields may indicate multiple RLC entities connected to one MAC entity (MCG MAC entity or SCG MAC entity) of the UE, and therefore connected to all bearers for which the packet repetition technology is configured. The corresponding L field may be mapped in ascending (or descending) order to the logical channel identifier value (or new identifier value) configured for all RLC entities connected to one MAC entity (MCG MAC entity or SCG MAC entity) and therefore connected to all bearers for which the packet repetition technology is configured. As another approach, the corresponding L field can be mapped in ascending (or descending) order to the Scell ​​identifier value (SCell index) mapped to the logical channel identifier configured for a MAC entity (MCG MAC entity or SCG MAC entity) and therefore connected to all RLC entities configured with packet repetition technology.

[0277] In addition, the P field may be defined and used as in Example 4-1 11-01. The P field is a field used to dynamically indicate that an existing primary RLC entity is changed to a secondary RLC entity, the existing primary RLC entity is connected to a bearer for which a packet repetition transmission technology is configured and corresponds to a MAC entity, and indicates that another secondary RLC entity is changed to a new primary RLC entity. For example, when the P field is configured to 1, the MAC CE may not indicate the activation and deactivation of an RLC entity connected to a bearer for which a packet repetition transmission technology is configured and corresponds to a MAC entity, but may indicate that a new primary RLC entity is configured or changed for the bearer. That is, in the case where the P field is configured to 1 and an L field in the L field is configured to 1, this situation may mean that the secondary RLC entity corresponding to the L field configured to 1 will be configured as a new primary RLC entity, and the existing primary RLC entity will be changed to a secondary RLC entity. In addition, considering the logical channel identifier (or new identifier value) of the secondary RLC entity that is newly changed due to the P field, the L field corresponding to the bearer index field may be mapped again in ascending (or descending) order. When the P field is configured to 0, the MAC CE may indicate the activation and deactivation of the RLC entity connected to the bearer for which the packet repetition transmission technology is configured. In the above description, when the L field is 0 (or 1), this may indicate that the secondary RLC entity corresponding thereto will be deactivated, and when the L field is 1 (or 0), this may indicate that the secondary RLC entity corresponding thereto will be activated. In addition, the cell group (MCG or SCG) may be indicated by defining the G field.

[0278] Embodiment 7-2 of the present disclosure proposes a method for defining a new MAC CE, and dynamically activating (or instructing to perform repeated transmission) some RLC entities among multiple RLC entities or deactivating (or instructing to stop repeated transmission) some RLC entities based on the MAC CE.

[0279] In Example 7-2, a separate logical channel identifier may be allocated for the proposed MAC CE, and the L field may not exist in the MAC header of the MAC CE. However, the present disclosure is not limited to this. In addition, the MAC header and the MAC CE may have a fixed size. However, the present disclosure is not limited to this. In Example 7-2, the bearer configured with the packet repetition technology may not be indicated. That is, multiple L bits (for example, 16) may be defined, and multiple L fields may indicate multiple RLC entities connected to a MAC entity (MCG MAC entity or SCG MAC entity) connected to the UE and therefore connected to all bearers for which the packet repetition technology is configured. The corresponding L field may be mapped in ascending (or descending) order to the logical channel identifier value (or new identifier value) configured for all secondary RLC entities connected to one MAC entity (MCG MAC entity or SCG MAC entity) and therefore connected to all bearers for which the packet repetition technology is configured. As another method, the corresponding L field may be mapped in ascending (or descending) order to the SCell identifier value (Scell ​​index) mapped to the logical channel identifier configured for all secondary RLC entities connected to one MAC entity (MCG MAC entity or SCG MAC entity) and therefore connected to all bearers configured with the packet repetition technology. Because the primary RLC entity may not be deactivated, the L field may only indicate the secondary RLC entity. That is, unlike Example 7-1, in Example 7-2, the L field may only indicate the secondary RLC entity.

[0280] In addition, the P field may be defined and used as in Example 4-1 11-01. The P field is a field used to dynamically indicate that an existing primary RLC entity is changed to a secondary RLC entity, the existing primary RLC entity is connected to a bearer for which a packet repetition transmission technology is configured and corresponds to a MAC entity, and indicates that another secondary RLC entity is changed to a new primary RLC entity. For example, when the P field is configured to 1, the MAC CE may not indicate the activation and deactivation of an RLC entity connected to a bearer for which a packet repetition transmission technology is configured and corresponds to a MAC entity, but may indicate that a new primary RLC entity is configured or changed for the bearer. That is, in the case where the P field is configured to 1 and an L field in the L field is configured to 1, this situation may mean that the secondary RLC entity corresponding to the L field configured to 1 will be configured as a new primary RLC entity, and the existing primary RLC entity will be changed to a secondary RLC entity. In addition, considering the logical channel identifier (or new identifier value) of the secondary RLC entity that is newly changed due to the P field, the L field corresponding to the bearer index field may be mapped again in ascending (or descending) order. When the P field is configured to 0, the MAC CE may indicate the activation and deactivation of the RLC entity connected to the bearer for which the packet repetition transmission technology is configured. In the above description, when the L field is 0 (or 1), this may indicate that the secondary RLC entity corresponding thereto will be deactivated, and when the L field is 1 (or 0), this may indicate that the secondary RLC entity corresponding thereto will be activated. In addition, the cell group (MCG or SCG) may be indicated by defining the G field.

[0281] Figure 1P Embodiment 8 of an embodiment of the present disclosure is shown, in which when multiple RLC entities (or logical channel identifiers) are configured for a UE configured with packet repetition transmission technology, all configured RLC entities are dynamically activated (or instructed to perform repetition transmission) or deactivated (or instructed to stop repetition transmission).

[0282] As described below, embodiment 8 according to the present disclosure is provided, in which when multiple RLC entities (or logical channel identifiers) are configured for a UE configured with a packet repetition transmission technology, all configured RLC entities are dynamically activated (or instructed to perform repetition transmission) or deactivated (or instructed to stop repetition transmission). In embodiment 8, when the DC technology is configured, the MCG BS can configure the MCG MAC entity connected to the UE and the activation and deactivation of the RLC entity for which the packet repetition transmission technology is configured, and the SCG BS can configure the SCG MAC entity connected to the UE and the activation and deactivation of the RLC entity for which the packet repetition transmission technology is configured.

[0283] Embodiment 8 1p-01 of the present disclosure proposes a method for defining a new MAC CE, and dynamically activating (or indicating to perform repeated transmission) or deactivating (or indicating to stop repeated transmission) all multiple secondary RLC entities based on the MAC CE. In Embodiment 8, a separate logical channel identifier may be assigned to the proposed MAC CE, and the L field may not exist in the MAC header of the MAC CE. However, the present disclosure is not limited to this. In addition, the MAC header and the MAC CE may have a fixed size. However, the present disclosure is not limited to this. In Embodiment 8, only the bearer configured with the packet repetition technology may be indicated, and the logical channel identifier or the SCell identifier may not be indicated.

[0284] In detail, in Example 8, for an MCG MAC entity (SCG MAC or MCGMAC), the maximum number of configurable packet repetition technologies is limited to 8, and the bearer identifier value of the bearer configured with the packet repetition transmission technology can be mapped to each bit of a 1-byte bitmap with a length of 8 bits in ascending order (or descending order).

[0285] When each bit of the bitmap indicates 0 (or 1), the secondary RLC entities connected to the bearer for which the packet repetition technology is configured and corresponding to the bits of the bitmap can all be deactivated, and when each bit indicates 1 (or 0), the secondary RLC entities connected to the bearer for which the packet repetition technology is configured and corresponding to the bits of the bitmap can all be activated.

[0286] That is, the number of packet repetitions to be performed on the bearer configured with the packet repetition technique, or the number of secondary RLC entities to be configured, may be determined by the following method: Figure 1E The configuration of the RRC message shown in FIG. 1 is determined by the configuration of the RRC message shown in FIG. 1 , and the MAC CE can indicate activation or deactivation of all secondary RLC entities connected to the bearer configured with packet repetition. By doing so, the MAC CE can have a simple structure, and can prevent the situation where only some of the multiple secondary RLC entities are activated or deactivated, thereby reducing the complexity of implantation of the UE and the BS.

[0287] For example, the BS may configure one RLC entity and three secondary RLC entities for the first bearer by using an RRC message, and may configure one RLC entity and two secondary RLC entities for the second bearer by using an RRC message. According to the configuration of the RRC message, the UE may receive the RRC message, and may configure one RLC entity and three secondary RLC entities for the first bearer, and may configure one RLC entity and two secondary RLC entities for the second bearer. In the case where the UE receives a MAC CE, when the MAC CE indicates 0 (or 1) with respect to the first bearer, the UE may deactivate all three secondary RLC entities connected to the first bearer, and when the MAC CE indicates 1 (or 0), the UE may activate all three secondary RLC entities connected to the first bearer. When the MAC CE indicates 0 (or 1) with respect to the second bearer, the UE may deactivate all two secondary RLC entities connected to the second bearer, and when the MAC CE indicates 1 (or 0), the UE may activate all two secondary RLC entities connected to the second bearer.

[0288] Figure 1T Embodiment 9 according to the present disclosure is shown, in which when multiple RLC entities (or logical channel identifiers) are configured for a UE configured with packet repetition transmission technology, all configured RLC entities are dynamically activated (or instructed to perform repetition transmission) or deactivated (or instructed to stop repetition transmission).

[0289] Embodiment 9 according to the present disclosure is provided as follows, wherein when multiple RLC entities (or logical channel identifiers) are configured for a UE configured with a packet repetition transmission technology, all configured RLC entities are dynamically activated (or instructed to perform repetition transmission) or deactivated (or instructed to stop repetition transmission). According to embodiment 9, when the DC technology is configured, the MCG BS can configure the MCG MAC entity connected to the UE and the activation and deactivation of the RLC entity for which the packet repetition transmission technology is configured, and the SCGBS can configure the SCG MAC entity connected to the UE and the activation and deactivation of the RLC entity for which the packet repetition transmission technology is configured.

[0290] Embodiment 9 1t-01 of the present disclosure proposes a method for defining a new MAC CE, and dynamically activating (or instructing to perform repeated transmission) or deactivating (or instructing to stop repeated transmission) some RLC entities among multiple RLC entities based on the MAC CE. In embodiment 9, a separate logical channel identifier (or a new identifier) ​​may be allocated to the new MAC CE, the L field may not exist in the MAC header of the MAC CE, and the MAC header and the MAC CE may have a fixed size.

[0291] The MAC CE 1t-01 in Example 9 may be Figure 1TThe structure shown has only the L field, and the position of the L field in the MAC CE structure or the sub-index of the L field can be mapped to the RLC entity or the bearer identifier value of the bearer in ascending order (or descending order) by using the method 1, method 2, method 3, method 4, method 5, method 6, method 7 or method 8 proposed in the present disclosure, wherein the packet repetition technology is configured for the bearer. That is, the position of the L field or the sub-index of the L field can indicate a bearer for which the packet repetition technology is configured. In addition, the three bits corresponding to the bearer can be configured to indicate multiple secondary RLC entities connected to the bearer for which the packet repetition technology is configured. By using the method 4, method 5, method 6, method 7 or method 8 proposed in the present disclosure, the three bits can be mapped to the corresponding RLC entity. The three bits can indicate multiple secondary RLC entities connected to the bearer for which the packet repetition technology is configured. Because the main RLC entity may not be deactivated, the BS may only indicate the activation or deactivation of the secondary RLC entity.

[0292] For example, when the L field has "a" and "b" as sub-indexes (e.g., L_(a, b), 1t-01), the sub-index "a" can indicate the a-th bearer in ascending order of the bearer identifier, and the sub-index "b" can indicate each of the three bits, and can indicate the b-th RLC entity (e.g., a secondary RLC entity) by using method 4, method 5, method 6, method 7, or method 8 proposed in the present disclosure. Therefore, when a bearer having 5 as a bearer identifier and a bearer having 8 as a bearer identifier of the packet repetition technique are configured for the UE, the primary RLC entity and the secondary RLC entity corresponding to the bearer having 5 as a bearer identifier may be mapped to L_(0, 0), L_(0, 1), and L_(0, 2) and thus may have a value of 0 or 1, the primary RLC entity and the secondary RLC entity corresponding to the bearer having 8 as a bearer identifier may be mapped to L_(1, 0), L_(1, 1), and L_(1, 2) and thus may have a value of 0 or 1, and all remaining L field values ​​are not used and are filled with a value of 0. A maximum of eight bearers for which packet repetition is configured may be configured.

[0293] The bearer identifier (e.g., 5 bits) can be configured as a natural number between 0 and 31 or 1 and 32 or a binary number corresponding thereto, the logical channel identifier (e.g., 6 bits) can be configured as a natural number between 0 and 63 or a binary number corresponding thereto, and the cell group identifier (e.g., 2 bits) can be configured as a natural number between 0 and 3 or 1 and 4 or a binary number corresponding thereto.

[0294] According to Embodiment 1, Embodiment 2, Embodiment 3, Embodiment 4, Embodiment 5, Embodiment 6, Embodiment 7, Embodiment 8 or Embodiment 9 of the efficient MAC CE proposed in the present disclosure, the BS or UE may map each bit to a primary RLC entity or a secondary RLC entity. In addition, when the BS (or UE) activates or deactivates each RLC entity, the BS (or UE) may map each bit to the RLC entity by using Method 1, Method 2, Method 3, Method 4, Method 5, Method 6 or Method 6 proposed in the present disclosure.

[0295] In addition, the P field or the G field proposed in the present disclosure may be indicated in the MAC header. Since the MAC header includes a logical channel identifier, the MAC header may indicate activation and deactivation by defining a 1-bit indicator in the MAC header.

[0296] In addition, in the aforementioned embodiment, a new field may be defined in a MAC CE, an RRC message, or a MAC header to indicate that packet repetition is not performed in a bearer configured with packet repetition, and data is sent by distributing multiple different data to multiple RLC entities, thereby increasing the data rate. This method may also be applied to a packet repetition technology configured using a DC technology or a packet repetition technology configured using a CA technology.

[0297] In the aforementioned embodiment, when the activation and deactivation of multiple secondary RLC entities are indicated by MAC CE or MAC header, when all secondary RLC entities configured for bearers applying packet repetition technology are deactivated, the UE can stop packet repetition transmission and can operate as a normal bearer.

[0298] In the aforementioned embodiment, in the case where activation and deactivation of multiple secondary RLC entities are indicated by MAC CE or MAC header, when the secondary RLC entity configured for the bearer to which the packet repetition technique is applied is deactivated and thus only one secondary RLC entity is activated (for example, in the case where two secondary RLC entities among three activated or configured secondary RLC entities are deactivated, in the case where one secondary RLC entity among two activated or configured secondary RLC entities is deactivated, or in the case where one activated or configured secondary RLC entity is activated), the UE may receive an indication to deactivate one secondary RLC entity. That is, the MAC CE may indicate deactivation of all configured secondary RLC entities through an RRC message, or the UE may receive an indication to deactivate packet repetition for the bearer in such a manner that the MAC CE may indicate deactivation of all configured secondary RLC entities through an RRC message.

[0299] In the case where the UE receives an indication to deactivate a secondary RLC entity, the MAC CE indicates the deactivation of all configured secondary RLC entities through an RRC message, or the MAC CE indicates the deactivation of all configured secondary RLC entities through an RRC message so as to deactivate packet repetition with respect to the bearer, when the configuration of the primary RLC entity of the bearer for which packet repetition transmission is configured and the secondary RLC entity that was most recently deactivated (or has the minimum or maximum logical channel identifier value) or the secondary RLC entity preconfigured for the split bearer has the same configuration as the split bearer of the DC technology (i.e., when the primary RLC entity and the secondary RLC entity are connected to different MAC entities (MCG MAC or SCG MAC), or when the secondary RLC entity is connected to a MAC entity (e.g., SCG MAC) different from the MAC entity to which the first RLC entity is connected), the UE may stop packet repetition with respect to the bearer for which packet repetition transmission is performed, and may perform a fallback by which the bearer operates as a split bearer of the DC technology, and thus sends data by distributing a plurality of different data to different RLC entities (the primary RLC entity and the secondary RLC entity) so as to increase the data rate.

[0300] As another method, a preset indicator may be defined, configured, and indicated in an RRC message or MAC CE, and may indicate that a secondary RLC entity pre-configured to be used as a separate bearer is applied to the proposed packet repetition technique. Alternatively, the packet repetition technique may always be applied by using a preset indicator. Alternatively, the packet repetition technique may always be applied without a preset indicator.

[0301] In the aforementioned case, even when the UE receives an indication to perform deactivation on the secondary RLC entity, when the secondary RLC entity operates in acknowledgement mode (AM mode), the UE can continuously retransmit data for which no RLC acknowledgment (ACK) regarding successful transmission has been received from among the transmitted data, and can continuously send configured RLC PDUs that have not yet been sent.

[0302] In addition, in the aforementioned case, even when the UE receives an indication to perform deactivation on the secondary RLC entity, when the secondary RLC entity operates in an unconfirmed mode (UM mode), the UE may continuously transmit the configured RLC PDU that has not yet been transmitted. In addition, even when the UE receives an indication to perform deactivation on the secondary RLC entity, the UE may continuously receive DL data from the BS via the secondary RLC entity. In addition, in the case where the deactivated secondary RLC entity is activated, the UE may not initialize the RLC sequence number that has been used, and may configure the data to be transmitted by allocating the RLC sequence number that has not yet been transmitted.

[0303] Referring to FIG. 1 , when the BS configures a packet repetition technique for each bearer of the UE, in order to reduce the waiting time caused by the activation of the secondary RLC entity connected to the bearer configured with the packet repetition technique, when the BS configures the secondary RLC entity to be connected to the bearer through an RRC message, the BS can indicate the activation of each secondary RLC entity. That is, when the BS defines a preset indicator and configures the secondary RLC entity through an RRC message, the BS can activate or deactivate each secondary RLC entity. In addition, the BS and the UE can operate when they think that the configured secondary RLC entity will be activated.

[0304] According to the method proposed in the present disclosure, when the BS configures the packet repetition technology for each bearer of the UE, the BS can configure the configuration information about multiple RLC entities through RRC messages, which RLC entities are connectable and available relative to the PDCP entity of each bearer, and can configure which RLC entities among the multiple RLC entities will be activated. In addition, a method for designing a new MAC CE is provided for dynamically indicating which RLC entities among multiple configured RLC entities will be activated or deactivated. The present disclosure provides a description of an additional embodiment, wherein, when the BS indicates to the UE whether to activate and deactivate each of the multiple RLC entities of the bearer configured with the packet repetition transmission technology, by using the MAC CE, the MAC entity of the UE indicates whether to activate and deactivate the RLC entity of the PDCP entity of the UE, so that the PDCP entity can continuously apply or stop applying packet repetition to the RLC entity. That is, when the PDCP entity obtains (or receives) an indication from the MAC entity, which indicates that a certain RLC entity is deactivated, the PDCP entity does not perform packet repetition on the deactivated RLC entity, does not send (or indicate) a duplicate data discard indication to the deactivated RLC entity, which duplicate data discard indication occurs due to the successful transmission of duplicate data by another RLC entity, and can instruct the deactivated RLC entity to discard all data and stop packet repetition transmission to the deactivated RLC entity.

[0305] However, when the timer for each packet for selective repetition is running or the timer for determining whether to release repeated transmission is running, the PDCP entity may stop the timer for each packet for selective repetition or the timer for determining whether to release repeated transmission. In addition, when the PDCP entity receives an indication from the MAC entity indicating that a certain RLC entity is activated, the PDCP entity may re-perform packet repetition on the activated RLC entity, and when the timer for selective repetition is set or the timer for determining whether to release repeated transmission is set, the PDCP entity may start the timer.

[0306] The timer for selective repetition data or the timer for determining whether to release repeated transmission may be triggered when the repeated data is sent for the first time. When another RLC entity cannot send repeated data before the timer for selective repetition data or the timer for determining whether to release repeated transmission expires, repeated transmission may be released for the corresponding data, and the timer for selective repetition data or the timer for determining whether to release repeated transmission may be run for each data. The timer for selective repetition data or the timer for determining whether to release repeated transmission may be stopped after the successful transmission of the repeated data is confirmed, and repeated transmission of the corresponding data may be stopped. That is, the PDCP entity for the bearer configured with the packet repetition transmission technology may perform each of the activation process and the deactivation process on each RLC entity configured for the bearer configured with the packet repetition transmission technology in response to the indication of the MAC entity of the UE.

[0307] In addition, when the BS configures multiple RLC entities for each bearer (or PDCP entity) configured with the packet repetition technology, the BS can configure which cell or frequency is used to send repeated data to be processed and configured by each RLC entity, so that the corresponding repeated data can be sent via different cells, so that the BS and the UE can each have a multiplexing gain. Therefore, in the present disclosure, the BS can configure mapping information for the UE via an RRC message so that data is sent to each specific cell, the data is generated by multiple RLC entities connected to the PDCP entity for which the packet repetition technology is configured, or the data corresponds to the logical channel identifier of each RLC entity.

[0308] Therefore, hereinafter, when an RLC entity is configured via an RRC message for a bearer for which a packet repetition technique is configured or a packet repetition transmission technique is activated for a bearer (or PDCP entity) for which an RLC entity is configured, a method performed by a UE autonomously and dynamically activates or deactivates each RLC entity based on signal measurement information or channel measurement information about a cell mapped to each RLC entity. Specifically, the BS may configure cell information and preset conditions for activating or deactivating each RLC entity, cell information mapped to each RLC entity, or a logical identifier corresponding to each RLC entity through an RRC message.

[0309] According to an embodiment of the present disclosure, the preset condition may be a condition for deactivating the RLC entity corresponding to the cell when the channel measurement information or signal strength (for example, signal-to-noise ratio (SNR), signal-to-interference-plus-noise ratio (SINR), reference signal received power (RSRP), reference signal received quality (RSRQ), etc.) of the cell is less than a threshold configured in the RRC message, or a condition for activating the RLC entity corresponding to the cell when the channel measurement information or the signal strength of the cell is greater than the threshold.

[0310] In addition, according to an embodiment of the present disclosure, the preset condition can specifically configure a method for measuring signal strength or a channel measurement method corresponding to a cell, can configure activation and deactivation rules, and can be extended to various embodiments. As described above, in the case where the UE autonomously performs activation or deactivation of the RLC entity based on channel measurement information about each cell, when the channel of a specific cell is very poor, it is difficult to successfully receive even if transmission is attempted, so that the UE can deactivate the RLC entity corresponding to the specific cell, thereby preventing unnecessary waste of transmission resources. When the channel of a specific cell is equal to or greater than the preset signal strength, the UE can activate the RLC entity corresponding to the specific cell, and thus can achieve low transmission waiting time and high reliability gain due to repeated transmission.

[0311] In addition, according to an embodiment of the present disclosure, when the UE autonomously activates or deactivates the RLC entity based on measurement information about a channel or signal of a cell mapped to the RLC entity of the UE, the MAC entity of the UE may indicate to the PDCP entity of the UE whether to activate or deactivate the RLC entity, so as to allow the PDCP entity to determine whether to continue to apply or stop packet repetition to the RLC entity. That is, when the PDCP entity receives an indication from the MAC entity, the indication indicating that a certain RLC entity is deactivated, the PDCP entity does not perform packet repetition on the deactivated RLC entity, does not indicate a duplicate data discard indication to the deactivated RLC entity, the duplicate data discard indication occurs due to the successful transmission of duplicate data by another RLC entity, and may instruct the deactivated RLC entity to discard all data and stop packet repetition transmission to the deactivated RLC entity. However, when a timer for each packet is running for selective repetition or a timer for determining whether to release repeated transmission is running, the PDCP entity may stop the timer for each packet for selective repetition or the timer for determining whether to release repeated transmission. In addition, when the PDCP entity receives an indication from the MAC entity indicating that a certain RLC entity is activated, the PDCP entity can re-perform packet repetition on the RLC entity, and when the timer for selective repetition is set or the timer for determining whether to release repeated transmission is set, the PDCP entity can start the timer for selective repetition or the timer for determining whether to release repeated transmission.

[0312] When repeated data is transmitted for the first time, a timer for each packet for selective repetition or a timer for determining whether to release repeated transmission may be triggered, and when another RLC entity cannot transmit repeated data until the timer for each packet for selective repetition or the timer for determining whether to release repeated transmission expires, repeated transmission may be released for the corresponding data, and a timer for each packet for selective repetition or a timer for determining whether to release repeated transmission may be run for each data. When successful transmission of repeated data is confirmed, the timer for each packet for selective repetition or the timer for determining whether to release repeated transmission is stopped, and repeated transmission of the data is stopped.

[0313] In the above description, the PHY entity may notify the MAC entity of channel measurement information or signal strength information about each cell, or may instruct the MAC entity whether to activate or deactivate each cell. When the MAC entity is instructed or determines activation and deactivation of each of a plurality of RLC entities configured with a packet repetition transmission technology through channel information or signal strength information about each cell, the PDCP entity may indicate whether to activate and deactivate each RLC entity.

[0314] In addition, if the activation and deactivation of the RLC entity is changed, the MAC entity can trigger a buffer status report, and thus can report again the amount of data that can be sent by the UE to the BS (for example, again taking into account the amount of data to be repeatedly transmitted, the buffer status report can be configured). This is because whether the RLC entity is activated may affect the amount of data to be repeatedly transmitted. The MAC entity can then exclude the logical channel of the deactivated RLC entity from the logical channel prioritization (LCP) process so that UL transmission resources are not allocated to the logical channel.

[0315] However, as described above, in the case where the UE autonomously activates or deactivates each RLC entity, based on the measurement information about the channel or signal of the cell mapped to each RLC entity, the BS cannot identify which RLC entity is activated or deactivated with respect to the bearer configured with the packet repetition transmission technology, and thus it is difficult to implement scheduling for the BS. Therefore, a new MACCE, a new RLC control PDU, or a new PDCP control PDU may be defined, and thus the UE may indicate to the BS which RLC entities the UE has activated or deactivated with respect to the bearer configured with the packet repetition transmission technology.

[0316] According to an embodiment of the present disclosure, for a method of indicating whether a plurality of RLC entities connected to each bearer are activated and deactivated by using a new MAC CE, the MAC CE may be configured as follows: Fig. 1I , Figure 1J , Figure 1K , Figure 1L , Figure 1M , Figure 1N , Fig.1O and Figure 1P The method in is designed, and the UE can indicate to the BS whether multiple RLC entities connected to each bearer for which the packet repetition technology is configured are activated and deactivated.

[0317] In addition, according to an embodiment of the present disclosure, in the case of defining a new RLC control PDU, the RLC control PDU can be configured by receiving an indication of whether to activate and deactivate each RLC entity from a MAC entity, and an indicator indicating activation or deactivation can be defined in the RLC control PDU so as to indicate the activation or deactivation of each RLC entity to the BS.

[0318] In addition, according to an embodiment of the present disclosure, in the case of indicating a PDCP control PDU, a PDCP entity for which a packet repetition transmission technique is configured may be configured by receiving an activation and deactivation indication from a MAC entity, and may be configured according to the following example: Fig. 1I , Figure 1J , Figure 1K , Figure 1L , Figure 1M , Figure 1N , Fig.1O and Figure 1P The PDCP control PDU is designed using the method in , and the UE can indicate to the BS whether multiple RLC entities connected to each bearer for which the packet repetition technology is configured are activated and deactivated.

[0319] In the following, the BS may configure a timer value to the UE via an RRC message, wherein the timer value is used for each bearer for which a packet repetition transmission technology is configured, or for each RLC entity for which a packet repetition transmission technology is configured, so that the MAC entity or PDCP entity of the UE operates the timer, and when the timer expires, the UE may deactivate multiple RLC entities configured for the bearer, or deactivate each of the multiple RLC entities configured for the bearer.

[0320] In the case where the UE operates the timer as described above, the BS can also operate the timer operated by the UE, so even when the RLC entity of the bearer configured with the packet repetition transmission technology is deactivated due to the expiration of the timer, the BS can recognize the deactivation of the RLC entity without an indication from the UE. A method for determining whether to activate and deactivate an RLC entity to which the timer-based packet repetition technology is applied is provided below.

[0321] Method 1: The BS may configure a timer for each bearer for which the packet repetition transmission technology is configured for the UE. Then, the PDCP entity or MAC entity of the UE may operate the timer for each bearer, and when the activation of the packet repetition transmission technology regarding the bearer is indicated via an RRC message or a MAC CE, the PDCP entity or MAC entity of the UE may start the timer. When the activation of the packet repetition transmission technology is re-indicated via an RRC message or a MAC CE, the PDCP entity or MAC entity of the UE may restart the timer. In addition, when the deactivation of the packet repetition transmission technology regarding the bearer is indicated via an RRC message or a MAC CE, the PDCP entity or MAC entity of the UE may stop the timer. When the timer expires, the PDCP entity or MAC entity of the UE may deactivate multiple RLC entities for the bearers for which the packet repetition transmission technology is configured. In addition, when the MAC entity operates the timer, the MAC entity may indicate to the PDCP entity the activation and deactivation of the packet repetition for the bearer for which the packet repetition transmission is configured, a buffer status report may be triggered, and a new buffer status report may be configured and sent to the BS.

[0322] Method 2: The BS may configure the UE with a timer for each RLC entity configured for a bearer for which the packet repetition transmission technology is configured. Then, the PDCP entity or MAC entity of the UE may operate the timer of each RLC entity, and when the activation of the packet repetition transmission technology for each RLC entity is indicated via an RRC message or a MAC CE, the PDCP entity or the MAC entity may start the timer. When the activation of the packet repetition transmission technology is re-indicated via an RRC message or a MAC entity, the PDCP entity or the MAC entity of the UE may restart the timer. In addition, when the deactivation of the packet repetition transmission technology for the bearer or each RLC entity is indicated via an RRC message or a MAC CE, the PDCP entity or the MAC entity of the UE may stop the timer. When the timer expires, the PDCP entity or the MAC entity of the UE may deactivate each RLC entity for which the packet repetition transmission technology is configured and which corresponds to the bearer of the timer. In addition, when the MAC entity operates the timer, the MAC entity may indicate to the PDCP entity the activation and deactivation of the packet repetition for the bearer for which the packet repetition transmission is configured, a buffer status report may be triggered, and a new buffer status report may be configured and sent to the BS.

[0323] Figure 1Q The UE operations proposed in this disclosure are shown.

[0324] In the present disclosure, when a packet repetition technique is configured for a UE by using an RRC message, the UE can configure the packet repetition technique for the indicated bearer and can configure multiple RLC entities (1q-05). When the BS indicates activation and deactivation of multiple RLC entities to the UE based on the embodiment proposed in the present disclosure (1q-10), the UE can activate or deactivate the corresponding secondary RLC entity according to the indication (1q-15). When a change of the primary RLC entity is indicated, the UE can change the primary RLC entity according to the indication.

[0325] Figure 1R is a block diagram of a configuration of a UE according to an embodiment of the present disclosure.

[0326] refer to Figure 1R , the UE may include a radio frequency (RF) processor 1r-10, a baseband processor 1r-20, a memory 1r-30, and a controller 1r-40.

[0327] The RF processor 1r-10 can perform functions of sending and receiving signals through a radio channel, such as frequency band conversion and amplification of signals. That is, the RF processor 1r-10 can up-convert the baseband signal provided from the baseband processor 1r-20 into an RF band signal, and then can send the RF band signal through an antenna, and can down-convert the RF band signal received through the antenna into a baseband signal. For example, the RF processor 1r-10 may include a transmitting filter, a receiving filter, an amplifier, a mixer, an oscillator, a digital-to-analog converter (DAC), an analog-to-digital converter (ADC), etc. However, the present disclosure is not limited thereto. Although in Figure 1R Only one antenna is shown in the figure, but the UE may include multiple antennas. The RF processor 1r-10 may include multiple RF chains. The RF processor 1r-10 can perform beamforming. For beamforming, the RF processor 1r-10 can adjust the phase and strength of signals to be sent or received through multiple antennas or antenna elements. The RF processor 1r-10 can perform MIMO operations and can receive multiple layers in MIMO operations. The RF processor 1r-10 can perform receive beam scanning by appropriately configuring multiple antennas or antenna elements, or can adjust the direction and beam width of the receive beam to coordinate with the transmit beam through the control of the controller 1r-40.

[0328] The baseband processor 1r-20 can convert between baseband signals and bit streams based on the physical entity specifications of the system. For example, for data transmission, the baseband processor 1r-20 can generate complex symbols by encoding and modulating the transmitted bit stream. For data reception, the baseband processor 1r-20 can reconstruct the received bit stream by demodulating and decoding the baseband signal provided from the RF processor 1r-10. For example, according to the OFDM scheme, for data transmission, the baseband processor 1r-20 can generate complex symbols by encoding and modulating the transmitted bit stream, the complex symbols can be mapped to subcarriers, and then OFDM symbols can be configured by performing an inverse fast Fourier transform (IFFT) and a cyclic prefix (CP) insertion. For data reception, the baseband processor 1r-20 can segment the baseband signal provided from the RF processor 1r-10 into OFDM symbol units, the signal mapped to the subcarrier can be reconstructed by performing a fast Fourier transform (FFT), and then the received bit stream can be reconstructed by demodulating and decoding the signal.

[0329] The baseband processor 1r-20 and the RF processor 1r-10 send and receive signals as described above. Therefore, the baseband processor 1r-20 and the RF processor 1r-10 may also be referred to as a transmitter, a receiver, a transceiver or a communicator. At least one of the baseband processor 1r-20 and the RF processor 1r-10 may include multiple communication modules to support a variety of different radio access technologies. At least one of the baseband processor 1r-20 and the RF processor 1r-10 may include different communication modules to process signals of different frequency bands. For example, different radio access technologies may include LTE networks, NR networks, etc. Different frequency bands may include ultra-high frequency (SHF) (e.g., 2.5GHz, 5GHz) bands and millimeter wave (mmWave) (e.g., 60GHz) bands. The UE may send signals to the BS and receive signals from the BS by using the baseband processor 1r-20 and the RF processor 1r-10. At this point, the signal may include control information and data.

[0330] The memory 1r-30 may store basic programs, applications, and data for UE operation, such as configuration information. The memory 1r-30 may provide stored data according to a request of the controller 1r-40. The memory 1r-30 may include any storage medium or a combination of storage media, such as a read-only memory (ROM), a random access memory (RAM), a hard disk, a compact disk (CD)-ROM, and a digital versatile disk (DVD). The memory 1r-30 may include a plurality of memories.

[0331] The controller 1r-40 can control the overall operation of the UE. For example, the controller 1r-40 can send and receive signals through the baseband processor 1r-20 and the RF processor 1r-10. The controller 1r-40 can record data on the memory 1r-30 or read data from the memory 1r-30. To this end, the controller 1r-40 may include at least one processor. For example, the controller 1r-40 may include a communication processor (CP) for controlling communications and an application processor (AP) for controlling upper layers such as applications. According to an embodiment of the present disclosure, the controller 1r-40 may include a multi-connection processor 1r-42 configured to process a multi-connection mode. According to the aforementioned embodiment, the controller 1r-40 can activate or deactivate multiple RLC entities, and can control each element in the UE to change the main RLC entity.

[0332] Figure 1S is a block diagram of a transmission / reception point (TRP) device in a wireless communication system according to an embodiment of the present disclosure.

[0333] According to an embodiment of the present disclosure, the TRP may be a BS. However, the present disclosure is not limited thereto, and the TRP may be an entity in the network that is capable of transmitting and receiving. Figure 1S , the BS may include an RF processor 1s-10, a baseband processor 1s-20, a communicator 1s-30, a memory 1s-40 and a controller 1s-50.

[0334] The RF processor 1s-10 can perform functions of sending and receiving signals through a radio channel, such as frequency band conversion and amplification of signals. The RF processor 1s-10 can up-convert the baseband signal provided from the baseband processor 1s-20 into an RF band signal, and then can transmit the RF band signal through an antenna, and can down-convert the RF band signal received through the antenna into a baseband signal. For example, the RF processor 1s-10 may include a transmit filter, a receive filter, an amplifier, a mixer, an oscillator, a DAC, an ADC, etc. However, the present disclosure is not limited thereto. Although in Figure 1S Only one antenna is shown in the figure, but the BS may include multiple antennas. The RF processor 1s-10 may include multiple RF chains. In addition, the RF processor 1s-10 may perform beamforming. For beamforming, the RF processor 1s-10 may adjust the phase and strength of a signal to be sent or received through multiple antennas or antenna elements. The RF processor 1s-10 may perform DL MIMO operations by sending one or more layers.

[0335] The baseband processor 1s-20 can convert between baseband signals and bit streams based on the physical entity specifications of the radio access technology. For example, for data transmission, the baseband processor 1s-20 can generate complex symbols by encoding and modulating the bit stream. For data reception, the baseband processor 1s-20 can reconstruct the received bit stream by demodulating and decoding the baseband signal provided from the RF processor 1s-10. For example, according to the OFDM scheme, for data transmission, the baseband processor 1s-20 can generate complex symbols by encoding and modulating the transmission bit stream, the complex symbols can be mapped to subcarriers, and then OFDM symbols can be configured by performing IFFT and CP insertion. For data reception, the baseband processor 1s-20 can segment the baseband signal provided from the RF processor 1s-10 into OFDM symbol units, the signal mapped to the subcarrier can be reconstructed by performing FFT, and then the received bit stream can be reconstructed by demodulating and decoding the signal. The baseband processor 1s-20 and the RF processor 1s-10 can send and receive signals as described above. In this way, the baseband processor 1s-20 and the RF processor 1s-10 can also be called a transmitter, a receiver, a transceiver, a communicator or a wireless communicator.

[0336] The communicator 1s-30 may provide an interface for communicating with other nodes in the network. The BS may send and receive signals to and from the UE by using the baseband processor 1s-20 and the RF processor 1s-10. At this point, the signal may include control information and data. According to an embodiment of the present disclosure, the communicator 1s-30 may be a backhaul communicator.

[0337] The memory 1s-40 can store basic programs, applications and data for BS operation, such as configuration information. In particular, the memory 1s-40 can store, for example, information about the bearers allocated to the connected UE and measurement results reported from the connected UE. The memory 1s-40 can store standard information for determining whether to provide a dual connection to the UE or release a dual connection from the UE. The memory 1s-40 can provide stored data according to the request of the controller 1s-50. The memory 1s-40 may include any storage medium or a combination of storage media, such as ROM, RAM, hard disk, CD-ROM and DVD. The memory 1s-40 may include multiple memories.

[0338] The controller 1s-50 can control the overall operation of the BS. For example, the controller 1s-50 can send and receive signals through the baseband processor 1s-20 and the RF processor 1s-10 or the communicator 1s-30. The controller 1s-50 can record data on the memory 1s-40 or read data from the memory 1s-40. To this end, the controller 1s-50 may include at least one processor. According to an embodiment of the present disclosure, the controller 1s-50 may include a multi-connection processor 1s-52 configured to process a multi-connection mode process.

[0339] The methods according to the embodiments of the present disclosure described herein or in the following claims may be implemented as hardware, software, or a combination of hardware and software.

[0340] When implemented as software, a computer-readable storage medium storing one or more programs (e.g., software modules) may be provided. One or more programs stored in the computer-readable storage medium are configured to be executed by one or more processors in an electronic device. One or more programs include instructions that instruct the electronic device to perform a method according to an embodiment of the present disclosure as described herein or in the following claims.

[0341] The program (e.g., software module or software) may be stored in a non-volatile memory, including RAM or flash memory, ROM, electrically erasable programmable read-only memory (EEPROM), a magnetic disk storage device, a CD-RO, a digital versatile disk (DVD), another optical storage device, or a cassette tape. Alternatively, the program may be stored in a memory that includes a combination of some or all of the above storage media. A plurality of such memories may be included.

[0342] In addition, the program can be stored in an attachable storage device that can be accessed through any communication network or combination thereof such as the Internet, an intranet, a local area network (LAN), a wide area network LAN (WLAN), and a storage area network (SAN). Such a storage device can access the electronic device through an external port. In addition, an additional storage device on a communication network can access the electronic device.

[0343] In the above-mentioned embodiment of the present disclosure, according to the embodiment of the present disclosure, one or more elements included in the present disclosure are expressed in singular or plural form. However, for the case assumed for the convenience of description, the singular or plural form is appropriately selected, the present disclosure is not limited to the singular or plural form, and the element expressed in the singular form may include multiple elements, and the element expressed in the plural form may include a single element.

[0344] It should be understood that the embodiments disclosed in the specification and the drawings should be considered only as descriptive, not restrictive. That is, it will be understood by those of ordinary skill in the art that various changes can be made in form and detail based on the technical concepts of the present disclosure. In addition, when necessary, the embodiments of the present disclosure can be combined to achieve. For example, the BS and the UE can operate in a manner that a part of an embodiment of the present disclosure is combined with a part of another embodiment of the present disclosure. In addition, modifications based on the technical scope of the embodiment can be applied to various systems, such as frequency division duplex (FDD) LTE systems, time division duplex (TDD) LTE systems, 5G or NR systems, etc.

Claims

1. A method performed by a user equipment (UE), the method comprising: receiving a first message of a packet data convergence protocol (PDCP) repetition configuring a radio bearer from a base station (BS); reconfiguring a primary radio link control (RLC) entity and one or more secondary RLC entities for PDCP; and receiving, from the BS, a second message related to deactivation of PDCP duplication; identifying, in case PDCP repetition is deactivated for a radio bearer, whether a separate secondary RLC entity is configured in one or more secondary RLC entities; as well as In case a separate secondary RLC entity is configured, a PDCP protocol data unit (PDU) is transmitted based on the primary RLC entity or the separate secondary RLC entity.

2. The method according to claim 1, wherein: The first message includes information indicating a logical channel identifier (LCID) of a detached secondary RLC entity for fallback to a detached bearer operation.

3. The method according to claim 1, wherein: The primary RLC entity is associated with a first cell group, and the separate secondary RLC entity is associated with a second cell group different from the first cell group.

4. The method of claim 1, wherein the primary RLC entity is not deactivated and one or more secondary RLC entities are all deactivated.

5. The method according to claim 1, further comprising: One or more duplicate PDCP PDUs in one or more secondary RLC entities are discarded.

6. A method performed by a base station (BS), the method comprising: sending a first message to a user equipment (UE) to configure a packet data convergence protocol (PDCP) repetition of a radio bearer, wherein the first message is associated with a primary radio link control (RLC) entity and configures one or more secondary RLC entities for PDCP repetition in the UE; sending a second message related to deactivation of PDCP duplication to the UE; and In case that PDCP repetition is deactivated for a radio bearer and a separate secondary RLC entity is configured in one or more secondary RLC entities, a PDCP protocol data unit (PDU) transmitted based on a primary RLC entity or a separate secondary RLC entity is received from a UE.

7. The method according to claim 6, wherein: The first message includes information indicating a logical channel identifier (LCID) of a detached secondary RLC entity for fallback to a detached bearer operation.

8. The method according to claim 6, wherein: The primary RLC entity is associated with a first cell group, and the separate secondary RLC entity is associated with a second cell group different from the first cell group.

9. The method of claim 6, wherein the primary RLC entity is not deactivated and one or more secondary RLC entities are all deactivated.

10. The method according to claim 6, wherein: One or more duplicate PDCP PDUs in one or more secondary RLC entities are discarded.

11. A user equipment UE in a wireless communication system, the UE comprising: transceiver; and Controller, configured as: receiving, via the transceiver, from a base station (BS) a first message for configuring a packet data convergence protocol (PDCP) repetition of a radio bearer, reconfiguring a primary radio link control (RLC) entity and one or more secondary RLC entities for PDCP, and receiving, via the transceiver, from the BS a second message related to deactivation of PDCP repetition, identifying whether a separate secondary RLC entity is configured in one or more secondary RLC entities in case PDCP repetition is deactivated for the radio bearer, and In case a separate secondary RLC entity is configured, a PDCP protocol data unit (PDU) is transmitted based on the primary RLC entity or the separate secondary RLC entity.

12. The UE according to claim 11, wherein: The first message includes information indicating a logical channel identifier (LCID) of a detached secondary RLC entity for fallback to a detached bearer operation.

13. The UE according to claim 11, wherein: The primary RLC entity is associated with a first cell group, and the separate secondary RLC entity is associated with a second cell group different from the first cell group.

14. The UE of claim 11, wherein the primary RLC entity is not deactivated and the one or more secondary RLC entities are all deactivated.

15. The UE according to claim 11, wherein the controller is further configured to: One or more duplicate PDCP PDUs in one or more secondary RLC entities are discarded.

16. A base station BS in a wireless communication system, the BS comprising: transceiver; and Controller, configured as: sending, via the transceiver, to a user equipment (UE) a first message configuring a packet data convergence protocol (PDCP) repetition of a radio bearer, wherein the first message is associated with a primary radio link control (RLC) entity and configures one or more secondary RLC entities for PDCP repetition in the UE, sending, via the transceiver, to the UE a second message related to deactivation of PDCP repetition, and In case that PDCP repetition is deactivated for a radio bearer and a separate secondary RLC entity is configured in one or more secondary RLC entities, a PDCP protocol data unit (PDU) transmitted based on a primary RLC entity or a separate secondary RLC entity is received from a UE via the transceiver.

17. The BS according to claim 16, wherein: The first message includes information indicating a logical channel identifier (LCID) of a detached secondary RLC entity for fallback to a detached bearer operation.

18. The BS according to claim 16, wherein: The primary RLC entity is associated with a first cell group, and the separate secondary RLC entity is associated with a second cell group different from the first cell group.

19. The BS of claim 16, wherein the primary RLC entity is not deactivated and the one or more secondary RLC entities are all deactivated.

20. The BS according to claim 16, wherein: One or more duplicate PDCP PDUs in one or more secondary RLC entities are discarded.

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