User equipment and methods thereof, base stations and methods thereof

Abstract

This disclosure provides a user equipment and a method thereof, as well as a base station and a method thereof. The method performed by the user equipment includes: receiving a Radio Resource Control (RRC) message from the base station, the RRC message containing information related to the repeating of Packet Data Convergence Protocol (PDCP) for a radio bearer and / or the activation configuration of the associated Radio Link Control (RLC) entity; and, based on the information, performing the repeating of PDCP for the radio bearer and / or the activation configuration of the associated RLC entity. This improves the communication efficiency and reliability of the wireless communication system.

Description

TECHNICAL FIELD

[0001] The present disclosure relates to the technical field of wireless communication, and more particularly, to a user equipment and method thereof, a base station and method thereof. BACKGROUND

[0002] In September 2018, at the 3rd Generation Partnership Project (3GPP) RAN #81 plenary meeting, Nokia proposed a study item on 5G (or called NR) Industrial Internet of Things (IIOT) (see Non-Patent Literature: RP-182090: Revised SID: Study on NR Industrial Internet of Things (IIoT)), which was approved. One of the goals of this study item is to improve the reliability and reduce the latency of data transmission through data duplication, including: (1) resource-efficient PDCP duplication, such as avoiding unnecessary duplicate transmissions; (2) more than twice PDCP duplication using dual connectivity (DC) or carrier aggregation (CA).

[0003] In Release 15, a bearer supporting PDCP duplication can be configured with at most two RLC entities. The initial state of a bearer configured with PDCP duplication is indicated by the pdcp-Duplication information element (see 3GPP TS 38.331 for the detailed description of this information element) whether the PDCP duplication function is activated or not at the initial time. In carrier aggregation, for a bearer whose initial PDCP duplication function is not activated, its data is transmitted through the logical channel indicated by the primaryPath information element (see 3GPP TS 38.331 for the detailed description of this information element). In dual connectivity, for a bearer whose initial PDCP duplication function is not activated, whether its data is transmitted through the logical channel indicated by the primaryPath information element or in a separate bearer manner is determined according to the amount of data to be transmitted.

[0004] In NR IIOT, to achieve the goal of using dual connectivity or carrier aggregation to implement twice or more than twice PDCP duplication, some manufacturers propose a way to configure multiple RLC entities for a bearer supporting PDCP duplication but activate only some of them each time (i.e., a PDCP entity configured with PDCP duplication delivers PDCP PDUs to two or more RLC entities associated and activated). The network can indicate whether to activate PDCP duplication and / or the activated RLC entity through RRC signaling or medium access control control element (MAC CE). The present disclosure discusses related issues involved in configuring and / or activating / deactivating PDCP duplication and / or RLC entities. SUMMARY

[0005] To solve the above problems in the related art, the disclosure provides a user equipment and a method thereof, a base station and a method thereof, which can perform appropriate PDCP duplication and / or activation configuration of associated RLC entities based on information about PDCP duplication and / or activation configuration of associated RLC entities of a radio bearer, thereby improving communication efficiency and reliability of a wireless communication system.

[0006] According to a first aspect of the disclosure, a method performed by a user equipment includes receiving, from a base station, a radio resource control (RRC) message including information about packet data convergence protocol (PDCP) duplication and / or activation configuration of associated radio link control (RLC) entities of a radio bearer; and based on the information, performing PDCP duplication and / or activation configuration of associated RLC entities of the radio bearer.

[0007] In the above method, in a case where the information does not include a parameter indicating an initial PDCP duplication status of the associated RLC entity, at least one of the following operations can be performed: initial PDCP duplication statuses of all associated RLC entities are activated and / or an initial PDCP duplication status of the corresponding radio bearer is activated; initial PDCP duplication statuses of all associated RLC entities are deactivated and / or an initial PDCP duplication status of the corresponding radio bearer is deactivated; for a signaling radio bearer (SRB), initial PDCP duplication statuses of all associated RLC entities are activated and / or an initial PDCP duplication status of the corresponding SRB is activated; and for a data radio bearer (DRB), initial PDCP duplication statuses of all associated RLC entities are deactivated and / or an initial PDCP duplication status of the corresponding DRB is deactivated.

[0008] In the above method, in a case where the information does not include a parameter indicating an initial PDCP duplication status of the associated RLC entity, at least one of the following operations can be performed: initial PDCP duplication statuses of all associated RLC entities are activated and / or an initial PDCP duplication status of the corresponding radio bearer is activated; initial PDCP duplication statuses of all associated RLC entities are deactivated and / or an initial PDCP duplication status of the corresponding radio bearer is deactivated; for a signaling radio bearer (SRB), initial PDCP duplication statuses of all associated RLC entities are activated and / or an initial PDCP duplication status of the corresponding SRB is activated; and for a data radio bearer (DRB), initial PDCP duplication statuses of all associated RLC entities are deactivated and / or an initial PDCP duplication status of the corresponding DRB is deactivated.

[0009] In the above method, in a case where the information does not include a parameter indicating an initial PDCP duplication status of the associated RLC entity, at least one of the following operations can be performed: initial PDCP duplication statuses of all associated RLC entities are activated and / or an initial PDCP duplication status of the corresponding radio bearer is activated; initial PDCP duplication statuses of all associated RLC entities are deactivated and / or an initial PDCP duplication status of the corresponding radio bearer is deactivated; for a signaling radio bearer (SRB), initial PDCP duplication statuses of all associated RLC entities are activated and / or an initial PDCP duplication status of the corresponding SRB is activated; and for a data radio bearer (DRB), initial PDCP duplication statuses of all associated RLC entities are deactivated and / or an initial PDCP duplication status of the corresponding DRB is deactivated.

[0010] In the above method, in a case where the information does not include a parameter indicating an initial PDCP duplication status of the associated RLC entity, at least one of the following operations can be performed: initial PDCP duplication statuses of all associated RLC entities are activated and / or an initial PDCP duplication status of the corresponding radio bearer is activated; initial PDCP duplication statuses of all associated RLC entities are deactivated and / or an initial PDCP duplication status of the corresponding radio bearer is deactivated; for a signaling radio bearer (SRB), initial PDCP duplication statuses of all associated RLC entities are activated and / or an initial PDCP duplication status of the corresponding SRB is activated; and for a data radio bearer (DRB), initial PDCP duplication statuses of all associated RLC entities are deactivated and / or an initial PDCP duplication status of the corresponding DRB is deactivated.

[0011] In the above method, in a case where the information includes a parameter indicating that PDCP duplication is configured when a data radio bearer (DRB) is configured, the parameter includes a parameter indicating an initial PDCP duplication status of an associated RLC entity.

[0012] In the above method, the parameter indicating that PDCP duplication is configured is a parameter configuring uplink data transmission of a PDCP entity associated with more than two RLC entities.

[0013] According to a second aspect of the present disclosure, a user equipment is provided, comprising: a processor; and a memory storing instructions; wherein the instructions, when executed by the processor, perform the above method.

[0014] According to a third aspect of the present disclosure, a method performed by a base station is provided, comprising: generating a radio resource control (RRC) message including information related to configuration of packet data convergence protocol (PDCP) duplication and / or activation of associated radio link control (RLC) entities of a radio bearer in the RRC message; and transmitting the RRC message to a user equipment to configure the user equipment to perform the PDCP duplication and / or the activation of the associated RLC entities of the radio bearer based on the information.

[0015] According to a fourth aspect of the present disclosure, a base station is provided, comprising: a processor; and a memory storing instructions; wherein the instructions, when executed by the processor, perform the above method.

[0016] Inventive Effects

[0017] According to the user equipment and the method thereof, the base station and the method thereof based on the present disclosure, appropriate PDCP duplication and / or activation of associated RLC entities can be performed based on information related to configuration of PDCP duplication and / or activation of associated RLC entities of a radio bearer, so that communication efficiency and reliability of a wireless communication system can be improved. BRIEF DESCRIPTION OF DRAWINGS

[0018] The above and other features of the present disclosure will become more apparent by describing in detail our embodiments thereof with reference made to the accompanying drawings, of which:

[0019] Figure 1 A flowchart representing a method 100 in a user equipment (UE) based on embodiments of the present disclosure.

[0020] Figure 2 A block diagram representing a user equipment 20 based on embodiments of the present disclosure.

[0021] Figure 3 A flowchart representing a method 300 in a base station based on embodiments of the present disclosure.

[0022] Figure 4 FIG. 1 shows a block diagram of a base station 40 according to an embodiment of the disclosure. DETAILED DESCRIPTION

[0023] The present disclosure will be described in detail by making reference to the drawings and specific embodiments. It should be noted that the present disclosure should not be limited to the specific embodiments described below. In addition, detailed descriptions of well-known technology related to the present disclosure are omitted to prevent obscuring the understanding of the present disclosure.

[0024] Some terms related to the present disclosure are described below. Unless otherwise specified, the terms related to the present disclosure are defined as follows.

[0025] RRC: Radio Resource Control

[0026] PDCP: Packet Data Convergence Protocol

[0027] RLC: Radio Link Control. The transmission mode of the RLC entity can be configured as one of a transparent mode TM, an unacknowledged mode UM, or an acknowledged mode AM.

[0028] PDU: Protocol Data Unit

[0029] SDU: Service Data Unit

[0030] In the present disclosure, data received from or transmitted to an upper layer is referred to as an SDU, and data transmitted to or received from a lower layer is referred to as a PDU. For example, data received from or transmitted to an upper layer by a PDCP entity is referred to as a PDCP SDU, and data received from or transmitted to a lower layer (i.e., an RLC entity) by a PDCP entity is referred to as a PDCP PDU (i.e., an RLC SDU). The PDCP PDU is a PDCP control PDU or a PDCP data PDU. The PDCP duplication function defined at present supports PDCP duplication of only a PDCP data PDU, and thus the PDCP duplication described in the present disclosure is for a PDCP data PDU.

[0031] Non-split bearer: In dual connectivity, a bearer in which a radio protocol is located in an MgNB or an SgNB and uses resources of the MgNB or the SgNB. The non-split bearer includes a non-split SRB and a non-split DRB.

[0032] Split bearer, in dual connectivity, a bearer whose radio protocol is located in both MgNB and SgNB and uses resources of both MgNB and SgNB. Split bearer includes split SRB and split DRB.

[0033] PDCP-Config information element: The information element PDCP-Config is used to set configurable PDCP parameters for a signaling radio bearer SRB and / or a data radio bearer DRB.

[0034] PDCP duplication, refers to sending a PDCP PDU twice or more times, the PDCP PDU is sent through RLC entities and / or logical channels associated to different carriers or carrier groups, i.e. the same PDCP PDU is submitted to two or more RLC entities at lower layer. In dual connectivity, the RLC entities and / or logical channels of a radio bearer configured with PDCP duplication belong to (or are respectively associated to) two different MAC entities. When a radio bearer is configured with PDCP duplication, a secondary RLC entity and a secondary logical channel are added for the radio bearer to handle the duplicated PDCP PDUs.

[0035] For a radio bearer configured with PDCP duplication, if PDCP duplication is activated, the transmitting PDCP entity duplicates the PDCP Data PDU and submits the PDCP Data PDU to the associated RLC entities activated for PDCP duplication; otherwise (corresponding to the case that PDCP duplication is not activated), for a non-split bearer, the transmitting PDCP entity submits the PDCP PDU to the primary RLC entity, for a split bearer, if the split secondary RLC entity is configured and the total amount of PDCP data volume and RLC data volume pending for initial transmission (as specified in TS 38.322 [5]) in the primary RLC entity and the split secondary RLC entity is equal to or larger than ul-DataSplitThreshold, the transmitting PDCP entity submits the PDCP PDU to either the primary RLC entity or the split secondary RLC entity, otherwise, the transmitting PDCP entity submits the PDCP PDU to the primary RLC entity. Wherein, the information element (IE) ul-DataSplitThreshold is contained in the PDCP-Config IE, and the specific description of the IE can be found in 3GPP technical specification TS 38.331, which is specifically excerpted as follows:

[0036]

[0037] It should be noted that in the present disclosure, if the transmitting PDCP entity of a split bearer is only associated with two RLC entities, it is considered that the split bearer is configured with a split secondary RLC entity, i.e., the split secondary RLC entity of the split bearer is an RLC entity (or secondary RLC entity) different from the primary RLC entity. For the transmitting PDCP entity or radio bearer configured with PDCP duplication and PDCP duplication is deactivated, the condition of being configured with a split secondary RLC entity can be replaced with the following condition: if the PDCP entity is associated with at least two RLC entities and the RLC entities respectively belong to or are associated to different cell groups (i.e., the primary cell group MCG and the secondary cell group SCG).

[0038] In the present disclosure, if the radio bearer PDCP entity is associated with more than two RLC entities, PDCP duplication is activated means that at least one secondary RLC entity is activated for PDCP duplication or at least one RLC entity other than the primary RLC entity is activated for PDCP duplication.

[0039] Primary path: also referred to as primary RLC entity, used for transmitting PDCP control PDU and PDCP data PDU, the primary path is configured by the parameter primaryPath carried in the RRC message and cannot be deactivated. The primary path is used to indicate the cell group ID and LCID of the primary RLC entity.

[0040] Secondary path: associated to other RLC entities of the RLC entities of the DRB configured with PDCP duplication, other than the primary path.

[0041] Split secondary RLC entity: in dual connectivity, an RLC entity used for split bearer operation in addition to the primary RLC entity.

[0042] Next, the method in the user equipment UE in the present disclosure is described, in particular, the control method involved in configuring PDCP duplication of a radio bearer in the user equipment UE is described. As an example, Figure 1 The flowchart of the method 100 in the user equipment UE based on the embodiments of the present disclosure is shown in FIG. 1.

[0043] In step S101, the user equipment UE receives from the base station a RRC message (e.g. RRCReconfiguration message) containing information related to the activation configuration of PDCP duplication and / or associated RLC entities for a radio bearer, e.g. parameter PDCP-Config (or parameter moreThanTwoRLC).

[0044] In step S102, the user equipment UE performs the activation configuration of PDCP duplication and / or associated RLC entities for a radio bearer based on the above information.

[0045] In one embodiment, if the parameter duplicationState is absent in the PDCP-Config (or parameter moreThanTwoRLC or the RRC message) contains, at least one of the following operations A~C is performed:

[0046] Operation A: the initial PDCP duplication status of all associated RLC entities is activated (applicable to all radio bearers), and / or the PDCP duplication status of the corresponding radio bearer is activated.

[0047] Operation B: the initial PDCP duplication status of all associated RLC entities is deactivated (applicable to all radio bearers), and / or the PDCP duplication status of the corresponding radio bearer is deactivated.

[0048] Operation C: for SRB, the initial PDCP duplication status of all associated RLC entities is activated and / or the PDCP duplication status of the corresponding SRB is activated; for DRB, the initial PDCP duplication status of all associated RLC entities is deactivated and / or the PDCP duplication status of the corresponding DRB is deactivated.

[0049] In one embodiment, the parameter duplicationState is only applied to DRB, i.e. this parameter can only be contained when PDCP duplication is configured for DRB; when SRB is configured to support PDCP duplication, the parameter duplicationState is not carried in the RRC message or parameter PDCP-Config or parameter moreThanTwoRLC or the UE ignores the value of duplicationState received (in other words, no matter what the value of the parameter duplicationState is, it is always considered that the initial PDCP duplication status of all associated RLC entities is activated).

[0050] In one embodiment, for SRB, if the parameter moreThanTwoRLC is present in the RRC message or parameter PDCP-Config, the initial PDCP duplication status of all associated RLC entities is activated; optionally, if the parameter duplicationState is present in the parameter moreThanTwoRLC, the UE ignores the value of the parameter duplicationState. In other words, no matter what the value of the parameter duplicationState is, it is always considered that the initial PDCP duplication status of all associated RLC entities is activated.

[0051] In one embodiment, when configuring SRB, if the parameter moreThanTwoRLC is present in the RRC message or parameter PDCP-Config, the parameter duplicationState must or necessarily be present in the parameter moreThanTwoRLC. Optionally, the parameter duplicationState indicates that the initial PDCP duplication status of all associated RLC entities is activated.

[0052] In one embodiment, for SRB, if the parameter moreThanTwoRLC is present in the RRC message or parameter PDCP-Config, it is considered that the initial PDCP duplication status of the SRB is activated.

[0053] In one embodiment, when configuring DRB, if the parameter moreThanTwoRLC is present in the RRC message or parameter PDCP-Config, the parameter duplicationState must be present in the parameter moreThanTwoRLC.

[0054] In the embodiments of the present disclosure, the associated RLC entity or all associated RLC entities refer to the PDCP entity associated RLC entity or all associated RLC entities of a radio bearer (except the primary RLC entity, because the parameter duplicationState is not used to indicate the primary RLC entity, and the primary RLC entity cannot be deactivated). The signaling radio bearer SRB includes non-split SRB and split SRB, the data radio bearer DRB includes non-split DRB and split DRB, and the radio bearer includes SRB and DRB.

[0055] In the embodiments of the present disclosure, the initial PDCP duplication state is the initial uplink PDCP duplication state, which refers to the PDCP duplication state of the associated RLC entity when the UE receives the RRC message and configures the corresponding SRB or DRB, or the PDCP duplication state of the corresponding RLC entity when the corresponding RLC entity is configured, or the PDCP duplication state of the corresponding radio bearer when the corresponding SRB or DRB is configured. The initial PDCP duplication state of the RLC entity is activated, which means that the PDCP entity delivers the PDCP PDU to the RLC entity. The initial PDCP duplication state of the RLC entity is deactivated, which means that the PDCP entity does not deliver the PDCP PDU to the RLC entity.

[0056] The parameters involved in the embodiments of the present disclosure are described below.

[0057] The parameter duplicationState indicates the initial uplink PDCP duplication state for the associated RLC entities. If the value thereof is set to true, the initial PDCP duplication state of the associated RLC entity is activated. The index of this indication (i.e., duplicationState) is determined by the ascending order of the logical channel identification of the RLC entity other than the primary RLC entity in the order of the primary cell group (MCG) first and the secondary cell group (SCG) second. If the duplicationState indicates that the initial PDCP duplication state of at least one associated RLC entity is activated, the initial PDCP duplication state of the corresponding radio bearer is activated; if the duplicationState indicates that the initial PDCP duplication state of all associated RLC entities is deactivated, the initial PDCP duplication state of the corresponding radio bearer is deactivated.

[0058] The parameter moreThanTwoRLC configures the UL data transmission when more than two RLC entities are associated with the PDCP entity; the presence of this parameter indicates that PDCP duplication is configured or the corresponding radio bearer is configured with PDCP duplication.

[0059] According to the method performed by the user equipment described above, appropriate PDCP repetition and / or activation configuration of the associated RLC entities can be performed based on information related to the PDCP repetition of the radio bearer and / or the activation configuration of the associated RLC entities, thereby improving the communication efficiency and reliability of the wireless communication system.

[0060] also, Figure 2 A block diagram of a user equipment 20 according to an embodiment of the present disclosure is shown. Figure 2 As shown, the user equipment 20 includes a processor 201 and a memory 202. The processor 201 may include, for example, a microprocessor, a microcontroller, an embedded processor, etc. The memory 202 may include, for example, volatile memory (such as random access memory, RAM), a hard disk drive (HDD), non-volatile memory (such as flash memory), or other memory systems. Program instructions are stored on the memory 202. When executed by the processor 201, these instructions can perform the methods described in detail in this disclosure within the user equipment.

[0061] Furthermore, as an example, Figure 3 The diagram below illustrates a flowchart of method 300 in a base station based on an embodiment of the present disclosure. In step S301, an RRC message is generated, which contains information related to the PDCP repetition of a radio bearer and / or the activation configuration of the associated RLC entity. In step S302, the RRC message is sent to a user equipment, causing the user equipment to perform PDCP repetition of the radio bearer and / or the activation configuration of the associated RLC entity based on the information.

[0062] According to the method performed by the base station described above, appropriate PDCP repetition and / or activation configuration of associated RLC entities can be performed based on information sent to the user equipment related to the PDCP repetition of the radio bearer and / or the activation configuration of the associated RLC entities, thereby improving the communication efficiency and reliability of the wireless communication system.

[0063] also, Figure 4 A block diagram of a base station 40 according to an embodiment of the present disclosure is shown. Figure 4As illustrated, the base station 40 includes a processor 401 and a memory 402. As described above, the base station 40 in the present disclosure can be any type of base station, including but not limited to a Node B, an enhanced Node B eNB, a 5G communication system base station gNB, or a micro base station, a pico base station, a macro base station, a home base station, etc. The processor 401 can include, for example, a microprocessor, a microcontroller, an embedded processor, etc. The memory 402 can include, for example, a volatile memory (such as a random access memory RAM), a hard disk drive (HDD), a non-volatile memory (such as a flash memory), or other storage systems, etc. The memory 402 stores program instructions thereon. The instructions, when executed by the processor 401, can perform the above-described method in the base station as described in detail in the present disclosure.

[0064] The computer-executable instructions or programs running on the device according to the present disclosure can be programs that control a central processing unit (CPU) to enable a computer to implement the functions of the embodiments of the present disclosure. The programs or information processed by the programs can be temporarily stored in a volatile memory (such as a random access memory RAM), a hard disk drive (HDD), a non-volatile memory (such as a flash memory), or other storage systems.

[0065] The computer-executable instructions or programs for implementing the functions of the embodiments of the present disclosure can be recorded on a computer-readable storage medium. The corresponding functions can be implemented by causing a computer system to read the programs recorded on the recording medium and execute the programs. The so-called "computer system" here can be a computer system embedded in the device and can include an operating system or hardware (such as a peripheral device). The "computer-readable storage medium" can be a semiconductor recording medium, an optical recording medium, a magnetic recording medium, a short-time dynamic storage program recording medium, or any other computer-readable recording medium.

[0066] The various features or functional modules of the device used in the above-described embodiments can be implemented or executed by a circuit (for example, a single-chip or multi-chip integrated circuit). The circuit designed to perform the functions described in the specification can include a general-purpose processor, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA), or other programmable logic devices, discrete gates or transistor logic, discrete hardware components, or any combination thereof. The general-purpose processor can be a microprocessor, or any existing processor, controller, microcontroller, or state machine. The above-mentioned circuit can be a digital circuit or an analog circuit. In the case of the emergence of new integrated circuit technologies that replace existing integrated circuits due to advances in semiconductor technology, one or more embodiments of the present disclosure can also be implemented using these new integrated circuit technologies.

[0067] Furthermore, the present disclosure is not limited to the above-described embodiments. Although various examples of the embodiments have been described, the present disclosure is not limited thereto. Fixed or non-mobile electronic devices installed indoors or outdoors can be used as terminal devices or communication devices, such as AV devices, kitchen devices, cleaning devices, air conditioners, office devices, vending machines, and other home appliances.

[0068] As described above, the embodiments of the present disclosure have been described in detail with reference to the accompanying drawings. However, the specific configuration is not limited to the above-described embodiments, and the present disclosure includes any design modification without departing from the gist of the present disclosure. In addition, various modifications can be made to the present disclosure within the scope of the claims, and embodiments obtained by appropriately combining the technical means disclosed in the different embodiments are also included in the technical scope of the present disclosure. Furthermore, components described in the above-described embodiments having the same effects can be substituted for each other.

Claims

1. A user equipment (UE), comprising: a processor; and a memory storing instructions, wherein the instructions, when executed by the processor, perform: receiving, from a base station, a radio resource control (RRC) message; and determining whether packet data convergence protocol (PDCP) duplication is activated or deactivated for a data radio bearer (DRB) based on whether the RRC message includes an indication that at least one associated radio link control (RLC) entity other than a primary RLC entity is activated for PDCP duplication for the DRB, wherein the determining comprises: determining that the PDCP duplication is activated if the indication included in the RRC message indicates that at least one associated RLC entity other than the primary RLC entity is activated for PDCP duplication for the DRB; and determining that the PDCP duplication is deactivated if the RRC message does not include the indication that at least one associated RLC entity other than the primary RLC entity is activated for PDCP duplication for the DRB. the indication is configured only for the DRB.

2. The UE of claim 1, wherein, 3.A base station, comprising: a processor; and a memory storing instructions, wherein the instructions, when executed by the processor, perform: generating a radio resource control (RRC) message; and transmitting, to a user equipment (UE), the RRC message, wherein the UE determines whether packet data convergence protocol (PDCP) duplication is activated or deactivated for a data radio bearer (DRB) based on whether the RRC message includes an indication that at least one associated radio link control (RLC) entity other than a primary RLC entity is activated for PDCP duplication for the DRB, wherein: the UE determines that the PDCP duplication is activated if the indication included in the RRC message indicates that at least one associated RLC entity other than the primary RLC entity is activated for PDCP duplication for the DRB; and the UE determines that the PDCP duplication is deactivated if the RRC message does not include the indication that at least one associated RLC entity other than the primary RLC entity is activated for PDCP duplication for the DRB. the indication is configured only for the DRB. 5.A method performed by a base station, comprising:

4. The base station of claim 3, wherein, generating a radio resource control (RRC) message; and transmitting, to a user equipment (UE), the RRC message, wherein the UE determines whether packet data convergence protocol (PDCP) duplication is activated or deactivated for a data radio bearer (DRB) based on whether the RRC message includes an indication that at least one associated radio link control (RLC) entity other than a primary RLC entity is activated for PDCP duplication for the DRB, wherein: the UE determines that the PDCP duplication is activated if the indication included in the RRC message indicates that at least one associated RLC entity other than the primary RLC entity is activated for PDCP duplication for the DRB; and ​ ​ ​ In case the RRC message does not comprise an indication indicating that at least one associated RLC entity other than the primary RLC entity is activated for PDCP duplication of the DRB, the UE determines that the PDCP duplication is deactivated.

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