Method and apparatus for controlling duplicate packet transmission in a wireless communication system

Abstract

The present disclosure relates to a method and apparatus for controlling packet duplication transmission in a wireless communication system. According to an embodiment of the present disclosure, a method for controlling packet duplication transmission performed by a user equipment (UE) in a wireless communication system includes: receiving, from a base station, a packet duplication configuration for a radio bearer through a radio resource control (RRC) message; determining whether each of a plurality of radio link control (RLC) entities is configured for uplink packet duplication transmission; and when the packet duplication transmission is activated, performing the packet duplication transmission by using the RLC entity set for uplink packet duplication transmission.

Description

Technical Field

[0001] The present disclosure relates to a method and apparatus for controlling packet duplicate transmission in a wireless communication system. Background Art

[0002] In order to meet the growing demand for wireless data traffic after the commercialization of the fourth generation (4G) communication system, efforts have continued to develop an enhanced fifth generation (5G) communication system or a pre-5G communication system. For this purpose, the 5G or pre-5G communication system is referred to as a super 4G network communication system or a post-long term evolution (LTE) system. The 5G communication system defined by the Third Generation Partnership Project (3GPP) is referred to as a New Radio (NR) system. In order to achieve high data rates, it is being considered to implement the 5G communication system in the ultra-high frequency or millimeter wave (mmWave) band (e.g., 60 GHz band). In order to reduce path loss and increase the transmission distance in the ultra-high frequency band of the 5G communication system, various technologies such as beamforming, massive multiple-input multiple-output (massive MIMO), full-dimension MIMO (FD-MIMO), array antennas, analog beamforming, and large antennas are being discussed and applied to the NR system. In addition, in order to improve the network of the system, for the 5G communication system, various technologies such as advanced small cells, cloud radio access network (cloud RAN), ultra-dense network, device-to-device communication (D2D), wireless backhaul, mobile network, cooperative communication, coordinated multi-point (CoMP), and interference cancellation have been developed. Furthermore, for the 5G communication system, other technologies such as hybrid frequency shift keying (FSK) and quadrature amplitude modulation (QAM) modulation (FQAM) and sliding window superposition coding (SWSC) based on advanced coding modulation (ACM) technology and filter bank multicarrier (FBMC), non-orthogonal multiple access (NOMA), and sparse code multiple access (SCMA) based on advanced access technology have been developed.

[0003] Meanwhile, the Internet has evolved from a human-based network for creating and consuming information to the Internet of Things (IoT) where distributed components such as objects send, receive, and process information. The Internet of Everything (IoE) technology has emerged, combining IoT technology with technologies for processing big data through connection to cloud servers. To implement IoT, various technical elements are required, such as sensing technology, wired / wireless communication, network architecture, service interface technology, and security technology. In recent years, technologies including sensor networks for connecting between objects, machine-to-machine (M2M) communication, and machine type communication (MTC) have been studied. In the IoT environment, intelligent Internet technology (IT) services can be provided to collect and analyze data obtained from connected objects, thus creating new value in human life. Through the integration and combination of existing information technology (IT) and various industries, IoT can be applied to various fields, such as smart homes, smart buildings, smart cities, smart cars or connected vehicles, smart grids, healthcare, smart appliances, and advanced medical services.

[0004] Therefore, various attempts are being made to apply 5G communication systems to IoT networks. For example, 5G communication is achieved through technologies such as beamforming, MIMO, and array antennas, such as sensor networks, M2M communication, and MTC. Cloud RAN, as an application of the above big data processing technology, can be an example of the integration of 5G communication technology and IoT technology.

[0005] Due to the above characteristics and the development of mobile communication systems, various services can be provided, so a method for effectively providing such services is needed. Summary of the Invention

[0006] Solution to the Problem

[0007] According to an embodiment of the present disclosure, a method for a user equipment (UE) to control packet duplication transmission in a wireless communication system includes: receiving, via a radio resource control (RRC) message, a packet duplication configuration for a radio bearer from a base station; determining whether each of a plurality of radio link control (RLC) entities is configured for uplink packet duplication transmission; and when packet duplication transmission is activated, performing packet duplication transmission by using the RLC entity set for uplink packet duplication transmission.

[0008] According to an embodiment of the present disclosure, a user equipment (UE) for controlling packet duplication transmission in a wireless communication system includes: a transceiver; a memory; and at least one processor configured to: receive, from a base station via a radio resource control (RRC) message, a packet duplication configuration for a radio bearer; determine whether each of a plurality of radio link control (RLC) entities is configured for uplink packet duplication transmission; and when the packet duplication transmission is activated, perform the packet duplication transmission by using the RLC entity set for the uplink packet duplication transmission.

[0009] Advantageous Effects

[0010] According to an embodiment of the disclosure, an apparatus and a method capable of effectively providing services in a mobile communication system can be provided. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 The structure of a radio bearer configured with packet duplication transmission according to an embodiment is shown.

[0012] Figure 2 It is a diagram for describing the operation of packet duplication transmission according to an embodiment.

[0013] Figure 3 It is a diagram for describing the operation of packet duplication transmission according to another embodiment.

[0014] Figure 4 It is a diagram showing the operation of performing packet duplication transmission according to an uplink duplication configuration according to an embodiment.

[0015] Figure 5 It is a diagram showing a method for controlling packet duplication activation and deactivation performed by a base station according to an embodiment.

[0016] Figure 6 The format of a packet duplication activation / deactivation message according to an embodiment is shown.

[0017] Figure 7 The format of a packet duplication activation / deactivation message according to another embodiment is shown.

[0018] Figure 8 The format of a packet duplication activation / deactivation message according to another embodiment is shown.

[0019] Figure 9 The format of a packet duplication activation / deactivation message according to another embodiment is shown.

[0020] Figure 10 The format of a packet duplication activation / deactivation message according to another embodiment is shown.

[0021] Figure 11 It is a diagram showing a method for a user equipment (UE) to notify a base station whether the UE has a packet duplication activation function according to an embodiment.

[0022] Figure 12 It is a diagram showing an operation of performing packet duplication transmission according to an embodiment.

[0023] Figure 13 It is a block diagram showing an internal structure of a UE according to an embodiment.

[0024] Figure 14 It is a block diagram showing a configuration of a base station according to an embodiment.

[0025] Figure 15 It shows a structure of a radio bearer provided with packet duplication transmission according to another embodiment.

[0026] Figure 16 It is a diagram showing a method for a base station to control activation and deactivation of packet duplication according to another embodiment.

[0027] Figure 17 It is a diagram showing a method for a base station to control activation and deactivation in carrier aggregation of a cell according to an embodiment.

[0028] Figure 18 It is a diagram for describing a method of applying cell configuration when packet duplication transmission is deactivated according to an embodiment.

[0029] Figure 19 It is a diagram showing a method for applying cell restrictions to packet duplication according to an embodiment.

[0030] Figure 20 It is a diagram for describing an operation of deactivating a cell in a bearer provided with packet duplication according to an embodiment.

[0031] Figure 21 It is a diagram showing an operation of performing packet duplication in a transmitter packet data convergence protocol (PDCP) entity according to an embodiment.

[0032] Figure 22 It is a diagram for describing an operation of deactivating packet duplication transmission according to a specific radio link control (RLC) entity in a bearer configured with packet duplication according to an embodiment.

[0033] Figure 23 It is a diagram for describing an operation of applying cell restrictions when applying two or more cell groups according to an embodiment.

[0034] Figure 24 It is a block diagram showing an internal structure of a UE according to another embodiment.

[0035] Figure 25 is a block diagram showing the configuration of a base station according to another embodiment.

[0036] Figure 26 shows the format of a packet duplication activation / deactivation message according to another embodiment.

[0037] Figure 27 shows the format of a packet duplication activation / deactivation message according to another embodiment.

[0038] Figure 28 shows the format of a packet duplication activation / deactivation message according to another embodiment.

[0039] Figure 29 shows the media access control (MAC) sub-header format of a variable-size MAC control element (CE) according to an embodiment.

[0040] Figure 30 shows the MAC sub-header format of a fixed-size MAC CE according to an embodiment. Detailed Description

[0041] According to an embodiment of the present disclosure, a method for a user equipment (UE) to control packet duplication transmission in a wireless communication system includes: receiving, via a radio resource control (RRC) message, a packet duplication configuration for a radio bearer from a base station; determining whether each of a plurality of radio link control (RLC) entities is configured for uplink packet duplication transmission; and when packet duplication transmission is activated, performing packet duplication transmission by using the RLC entities that are set for uplink packet duplication transmission.

[0042] According to an embodiment of the present disclosure, determining whether each of a plurality of RLC entities is configured for uplink packet duplication transmission may include: receiving, via a media access control control element (MAC CE), information indicating packet duplication activation or deactivation of the plurality of RLC entities from the base station; and determining whether each of the plurality of RLC entities is configured for uplink packet duplication transmission based on the information indicating packet duplication activation or deactivation.

[0043] According to an embodiment of the present disclosure, the information indicating packet duplication activation or deactivation may include: radio bearer identification information including at least one of a radio bearer index or a radio bearer identifier (ID); and a plurality of fields respectively corresponding to the plurality of RLC entities.

[0044] According to an embodiment of the present disclosure, the plurality of fields respectively corresponding to a plurality of RLC entities may be at least one of a plurality of fields respectively corresponding to all RLC entities provided in a radio bearer and a plurality of fields respectively corresponding to RLC entities provided to be used for uplink packet duplication transmission in a packet duplication configuration of the radio bearer.

[0045] According to an embodiment of the present disclosure, an RRC message may include information about an RLC entity to be used for uplink packet duplication transmission among a plurality of RLC entities, and determining whether each of the plurality of RLC entities is configured for uplink packet duplication transmission may include determining whether each of the plurality of RLC entities is configured for uplink packet duplication transmission based on the information about the RLC entity to be used for uplink packet duplication transmission.

[0046] According to an embodiment of the present disclosure, when packet duplication transmission is activated, performing packet duplication transmission by using an RLC entity provided to be used for uplink packet duplication transmission may include: receiving, from a base station through a media access control control element (MAC CE), information indicating packet duplication activation or deactivation of the RLC entity provided to be used for uplink packet duplication transmission; and activating packet duplication transmission when the information indicating packet duplication activation is received.

[0047] According to an embodiment of the present disclosure, the information about the RLC entity to be used for uplink packet duplication transmission may include at least one of a list of RLC entities to be used for uplink packet duplication transmission, an ID of the RLC entity, a logical channel ID, or a combination of the logical channel ID and a cell group ID.

[0048] According to an embodiment of the present disclosure, when packet duplication transmission is activated, performing packet duplication transmission by using an RLC entity provided to be used for uplink packet duplication transmission may include: receiving, from a base station through a media access control control element (MAC CE), information indicating packet duplication activation or deactivation of a radio bearer; and activating packet duplication transmission when the information indicating packet duplication activation is received.

[0049] According to an embodiment of the present disclosure, a user equipment (UE) for controlling packet duplication transmission in a wireless communication system includes: a transceiver; a memory; and at least one processor configured to: receive, from a base station through a radio resource control (RRC) message, a packet duplication configuration for a radio bearer; determine whether each of a plurality of radio link control (RLC) entities is configured for uplink packet duplication transmission; and perform packet duplication transmission by using an RLC entity provided to be used for uplink packet duplication transmission when packet duplication transmission is activated.

[0050] According to an embodiment of the present disclosure, at least one processor may further be configured to: receive, from a base station, information indicating activation or deactivation of packet duplication for a plurality of RLC entities through a Media Access Control Control Element (MAC CE); and determine, based on the information indicating activation or deactivation of packet duplication, whether each of the plurality of RLC entities is configured for uplink packet duplication transmission.

[0051] According to an embodiment of the present disclosure, the information indicating activation or deactivation of packet duplication may include: radio bearer identification information including at least one of a radio bearer index or a radio bearer ID; and a plurality of fields respectively corresponding to the plurality of RLC entities.

[0052] According to an embodiment of the present disclosure, the plurality of fields respectively corresponding to the plurality of RLC entities may be at least one of a plurality of fields respectively corresponding to all RLC entities provided in a radio bearer and a plurality of fields respectively corresponding to RLC entities provided for uplink packet duplication transmission in a packet duplication configuration of the radio bearer.

[0053] According to an embodiment of the present disclosure, an RRC message may include information about RLC entities to be used for uplink packet duplication transmission among a plurality of RLC entities, and at least one processor may further be configured to determine, based on the information about the RLC entities to be used for uplink packet duplication transmission, whether each of the plurality of RLC entities is configured for uplink packet duplication transmission.

[0054] According to an embodiment of the present disclosure, at least one processor may further be configured to: receive, from a base station, information indicating activation or deactivation of packet duplication for an RLC entity provided for uplink packet duplication transmission through a Media Access Control Control Element (MAC CE); and activate packet duplication transmission when receiving the information indicating activation of packet duplication.

[0055] According to an embodiment of the present disclosure, the information about RLC entities to be used for uplink packet duplication transmission among a plurality of RLC entities includes at least one of a list of RLC entities to be used for uplink packet duplication transmission, an ID of an RLC entity, a logical channel ID, or a combination of a logical channel ID and a cell group ID.

[0056] Disclosed embodiments

[0057] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. When describing the embodiments, descriptions of technical content that is well-known in the technical field to which the present disclosure pertains and that is not directly related to the present disclosure will be omitted. The reason for doing this is to more clearly convey the gist of the present disclosure without obscuring the gist of the present disclosure by omitting unnecessary descriptions.

[0058] For the same reason, some components in the drawings may be shown exaggeratedly, omitted, or shown schematically. In addition, the sizes of the components do not fully reflect their actual sizes. Identical or corresponding components in the drawings are assigned the same reference numerals.

[0059] Referring to the drawings showing the embodiments, the advantages and features of the present disclosure and the methods for realizing them will become clear. However, the present disclosure may be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that the present disclosure will be thorough and complete, and will fully convey the concept of the present disclosure to those of ordinary skill in the art, and the present disclosure is defined only by the scope of the claims. Throughout the specification, the same reference numerals represent the same components.

[0060] It will be understood that the blocks in the process flow diagrams or combinations of the process flow diagrams can be executed by computer program instructions. These computer program instructions can be loaded into the processor of a general-purpose computer, a special-purpose computer, or other programmable data processing devices, so that these instructions executed by the processor of the computer or other programmable data processing devices create means for performing the functions described in the (multiple) flow diagram blocks. The computer program instructions can also be stored in a computer-usable or computer-readable memory capable of guiding the computer or another programmable data processing device to implement functions in a specific manner, so that the instructions stored in the computer-usable or computer-readable memory can also produce a manufactured item containing the instruction means for performing the functions described in the (multiple) flow diagram blocks. The computer program instructions can also be installed in the computer or other programmable data processing devices, so that a series of operation steps are performed on the computer or other programmable data processing devices to create a computer-executable process. Therefore, the instructions can also operate the computer or other programmable data processing devices to provide the steps for performing the functions described in the (multiple) flow diagram blocks.

[0061] In addition, each block may represent a module, a segment, or a part of the code, which includes one or more executable instructions for performing the (multiple) specified logical functions. It should also be noted that in some alternative implementations, the functions mentioned in the blocks may not occur in sequence. For example, according to the corresponding functions, two consecutively shown blocks may actually be executed substantially simultaneously, or sometimes in the reverse order.

[0062] As used herein, the terms "portion", "module", or "unit" refer to a unit that can perform at least one function or operation and can be implemented as a software element or a hardware element such as a field programmable gate array (FPGA) or an application specific integrated circuit (ASIC). However, the terms "portion", "module", or "unit" are not limited to software or hardware. The terms "portion", "module", or "unit" can be configured in an addressable storage medium or can be configured to run on at least one processor. Thus, according to embodiments of the present disclosure, the terms "portion", "module", or "unit" include: elements (such as software elements, object-oriented software elements, class elements, and task elements); programs; functions; attributes; programs; subroutines; program code segments; drivers; firmware; microcode; circuits; data; databases; data structures; tables; arrays, or variables. The functions provided by the elements and "portions", "modules", or "units" can be combined into a smaller number of elements and "portions", "modules", or "units" or can be divided into additional elements and "portions", "modules", or "units". In addition, the elements and "portions", "modules", or "units" can be configured to run on one or more central processing units (CPUs) in a device or a secure multimedia card. In addition, a "portion", "module", or "unit" can include one or more processors.

[0063] In the following description, for ease of explanation only, terms for identifying access nodes, terms for indicating network entities, terms for indicating messages, terms for indicating interfaces between network entities, terms for indicating various types of identification information, etc. are examples. Thus, the present disclosure is not limited to these terms and other terms with technically equivalent meanings can also be used.

[0064] For ease of explanation, the present disclosure uses terms and names defined in the 3rd Generation Partnership Project Long Term Evolution (3GPP LTE) standard or modified terms and names. However, the present disclosure is not limited to these terms and names and can be applied to systems based on other standards in the same manner. In the present disclosure, for ease of explanation, evolved Node B (eNB) and next generation Node B (gNB) can be used interchangeably. That is, a base station called an eNB can indicate a gNB. In the present disclosure, the term user equipment (UE) can represent various wireless communication devices, as well as cellular phones, narrowband Internet of Things (NB-IoT) devices, and sensors.

[0065] Figure 1 The structure of a radio bearer configured with packet duplication transmission according to an embodiment is shown.

[0066] Packet duplication transmission means duplicating a packet and sending the duplicated packet by a transmitter to multiple paths.

[0067] Refer toFigure 1 In a radio bearer structure according to an embodiment, four RLC entities, RLC1 1a-20, RLC2 1a-30, RLC3 1a-40, and RLC4 1a-50, are connected to a Packet Data Convergence Protocol (PDCP) entity, PDCP1 1a-10, to support multiple paths. However, the radio bearer structure is merely an example, and the number of RLC entities connected to the PDCP entity is not limited. In addition, the base station can configure the radio bearer structure according to the radio link and network structure.

[0068] In a radio bearer structure according to an embodiment, the layer that performs packet duplication can be the PDCP entity 1a-10, and the PDCP entity 1a-10 can perform packet duplication and then send the duplicated packets to two or more different RLC entities so that the RLC entities can independently perform packet transmission. Since the radio bearer includes a single PDCP entity regardless of packet duplication, the PDCP entity can correspond to a radio bearer identifier (ID). According to an embodiment, the radio bearer including the PDCP entity PDCP1 1a-10 can be a Data Radio Bearer (DRB) or a Signaling Radio Bearer (SRB).

[0069] The RLC entities, RLC1 1a-20, RLC2 1a-30, RLC3 1a-40, and RLC4 1a-50, can be classified into a primary RLC entity 1a-20 and secondary RLC entities 1a-30, 1a-40, and 1a-50 according to their uses. The primary RLC entity 1a-20 can always perform packet transmission regardless of the activation of packet duplication. The secondary RLC entities 1a-30, 1a-40, and 1a-50 can perform packet transmission only when packet duplication is activated. In addition, according to the setting method, the secondary RLC entities 1a-30, 1a-40, and 1a-50 may not participate in uplink packet transmission.

[0070] In the case of applying a split bearer, when the data to be sent is less than or equal to (or less than) a specific threshold, the transmitter can send the packet only to the primary RLC entity, and when the data is greater than (or greater than or equal to) the specific threshold, the transmitter can send the packet to all the primary RLC entities and the secondary RLC entities.

[0071] The setting of the above detailed operations can be included in at least one of the radio bearer configuration, RLC bearer configuration, PDCP configuration, and RLC configuration in a Radio Resource Control (RRC) configuration message and sent to the UE.

[0072] Figure 2 is a diagram for describing the operation of packet duplication transmission according to an embodiment.

[0073] In the following description, it is assumed that the structure of the radio bearer with packet duplication is Figure 1 the structure of the radio bearer shown.

[0074] Referring to Figure 2 , according to an embodiment, when packet duplication transmission is configured and activated, the transmitter PDCP entity 1b-10 may duplicate packet 1b-60 into a plurality of duplicated packets 1b-70, 1b-80, 1b-90, and 1b-100, and send the duplicated packets 1b-70, 1b-80, 1b-90, and 1b-100 to all pre-configured RLC entities 1b-20, 1b-30, 1b-40, and 1b-50. The RLC entities 1b-20, 1b-30, 1b-40, and 1b-50 may operate in an independent mode. When the RLC entities 1b-20, 1b-30, 1b-40, and 1b-50 operate in the RLC acknowledged mode (AM), the RLC entities 1b-20, 1b-30, 1b-40, and 1b-50 may independently perform ARQ (Automatic Repeat reQuest) operations.

[0075] As Figure 2 shown, when four RLC entities 1b-20, 1b-30, 1b-40, and 1b-50 have been configured in the radio bearer, the transmitter PDCP entity 1b-10 may generate four duplicated packets for one packet, and send the four duplicated packets to the four RLC entities 1b-20, 1b-30, 1b-40, and 1b-50 respectively.

[0076] Figure 3 is a diagram for describing the operation of packet duplication transmission according to another embodiment.

[0077] Performing packet duplication and then transmitting the same duplicated packets to multiple paths will reuse radio resources, which may lead to low radio resource utilization efficiency. Therefore, in order to reduce this inefficiency, it may be necessary to adjust the number of packets to be duplicated in radio network management. Additionally, downlink packet duplication transmission completely controlled by the base station and uplink packet duplication transmission controlled by the UE according to the settings of the base station may be performed by using different numbers of RLC entities respectively.

[0078] Referring to Figure 3, some of the pre-configured RLC entities among the RLC entities can perform packet duplication. According to an embodiment, although the transmitter PDCP entity 1c-10 duplicates the packet 1c-100, the transmitter PDCP entity 1c-10 can use three of the four RLC entities 1c-20, 1c-30, 1c-40, and 1c-50, namely RLC 1 1c-20, RLC2 1c-30, and RLC3 1c-40, for packet duplication without using all four RLC entities 1c-20, 1c-30, 1c-40, and 1c-50. Therefore, the RLC entity RLC4 1c-50 may not participate in the packet duplication transmission. Whether each RLC entity will participate in the packet duplication transmission can be configured by the base station. According to the RLC configuration of each RLC entity, the ul-duplication field set to true can indicate that the corresponding RLC entity participates in the packet duplication transmission, and the ul-duplication field set to false can indicate that the corresponding RLC entity does not participate in the packet duplication transmission.

[0079] Whether each RLC entity will participate in the packet duplication transmission can be set by another method. For example, a list of RLC entities to be used for packet duplication can be specified and passed in the PDCP configuration or radio bearer configuration. At this time, the corresponding RLC entity can be specified by specifying the logical channel identifier (LCID). Additionally, in a dual-connection or multi-connection structure, the corresponding RLC entity can be specified by a combination of the logical channel ID and the cell group ID. Furthermore, the ID of the RLC entity (RLC bearer) can be specified.

[0080] Whether the RLC entity participates in the packet duplication transmission indicated by the corresponding ul_duplication field can be changed by a packet duplication activation / deactivation message, which will be described later with reference to Figure 7 , Figure 8 and Figure 10 will be described. According to another embodiment, among the RLC entities for which the ul_duplication field has been set to true, the RLC entities to be actually activated and used for packet duplication transmission can be set.

[0081] Figure 4 is a diagram showing the operation of performing packet duplication transmission according to the uplink replication configuration according to an embodiment.

[0082] In operation 1d-10, packet duplication of a radio bearer can be set. Then, in operation 1d-20, the UE can check the (multiple) RLC entities that are set for uplink packet duplication transmission. According to an embodiment, since each RLC entity corresponds to a logical channel, it can be checked whether each logical channel is configured for uplink packet duplication. At this time, it can be determined whether the RLC entity or the logical channel is configured for uplink packet duplication by checking whether the corresponding ul-duplication field is configured as true or whether the list of RLC entities is used for packet duplication, as described above with reference to Figure 3 described.

[0083] When the RLC entity or the logical channel is configured for uplink packet duplication, in operation 1d-30, when packet duplication is activated, the RLC entity can be used for uplink packet duplication.

[0084] When the RLC entity or the logical channel is not set for uplink packet duplication, in operation 1d-40, when packet duplication is activated, the RLC entity may not be used for uplink packet duplication. In other words, when packet duplication is activated, the transmitter PDCP entity can send the duplicated packets to the RLC entity for packet duplication activation, thereby performing packet duplication transmission.

[0085] Figure 5 is a diagram showing a method for controlling packet duplication activation and deactivation performed by a base station according to an embodiment.

[0086] Packet duplication transmission may increase the consumption of radio resources because the same packet is sent using two or more RLC entities. Therefore, packet duplication transmission may result in low radio resource utilization efficiency. Therefore, it may not be preferable to always perform packet duplication. Therefore, it may be preferable to perform packet duplication transmission as needed. Making packet duplication actually performed in a radio bearer configured with packet duplication is called activation of packet duplication. On the contrary, making packet duplication not performed in a radio bearer configured with packet duplication is called deactivation of packet duplication.

[0087] In operation 1e-10, the base station can send a packet duplication activation / deactivation message to the UE. At this time, a message with the same format can be used for both activation and deactivation, and the activation and deactivation of packet duplication can be distinguished by the value included in the message. The packet duplication activation / deactivation message can indicate the radio bearer for which packet duplication will be activated or deactivated.

[0088] In operation 1e-20, after the UE receives the packet duplication activation / deactivation message, the UE can activate or deactivate packet duplication according to the indication included in the packet duplication activation / deactivation message.

[0089] In the following, reference will be made to Figures 6 to 10 describe in more detail the format of the packet duplication activation / deactivation message. Figure 6 The format of the packet duplication activation / deactivation message according to an embodiment is shown.

[0090] Referring to Figure 6 , the packet duplication activation / deactivation message may have a Media Access Control Control Element (MAC CE) format configured with 1 byte (in other words, 8 bitmaps). The bits of each bitmap may indicate the activation and deactivation status of the packet duplication transmission of a specific radio bearer, where 1 indicates activation and 0 indicates deactivation. In addition, 8 bitmaps may indicate the packet duplication activation and deactivation status of up to 8 radio bearers. The bearers indicated by bits D0 1f-10 to D7 1f-80 respectively may be applied by a preset method. According to an embodiment, the bits may be applied by the MAC entity that has sent the MAC CE in ascending order of the DRB ID of the radio bearer for which packet duplication has been set and for which there is an RLC entity. In addition, the bits may be applied by using the security key corresponding to the cell group to which the MAC entity that has sent the MAC CE belongs and in ascending order of the DRB ID of the radio bearer for which packet duplication has been set.

[0091] Figure 7 The format of the packet duplication activation / deactivation message according to another embodiment is shown.

[0092] Referring to Figure 7 , the packet duplication activation / deactivation message may have a MAC CE format. According to an embodiment, the packet duplication activation / deactivation message may include a DRB index 1g-10 and fields 1g-20, 1g-30, 1g-40, 1g-50, and 1g-60 corresponding to the RLC entity, Li (i = 1, 2, 3, 4, 5). The DRB index 1g-10 may be a preset value that may be applied as one of the following values.

[0093] - Specified in the DRM configuration according to the settings of the base station

[0094] - Applied in ascending order of the DRB ID of the radio bearer for which packet duplication has been set

[0095] - Applied by the MAC entity that has sent the MAC CE in ascending order of the DRB ID of the radio bearer for which packet duplication has been set and for which there is an RLC entity

[0096] - DRB ID value

[0097] The Li fields 1g-20, 1g-30, 1g-40, 1g-50, and 1g-60 may represent corresponding RLC entities, and each of the Li fields 1g-20, 1g-30, 1g-40, 1g-50, and 1g-60 may be set according to its bit value to indicate whether to use the corresponding RLC entity for packet duplication transmission. For example, a value of 1 in the Li field may indicate that the corresponding RLC entity is used for packet duplication transmission, and a value of 0 in the Li field may indicate that the corresponding RLC entity is not used for packet duplication transmission. The Li field may indicate the RLC entity by using a preset value, and the preset value may be applied as one of the following values.

[0098] - Applied in ascending (descending) order of the LCIDs of the primary cell group and then in ascending (descending) order of the LCIDs of the secondary cell group

[0099] - In ascending order of the preset index corresponding to the RLC entity

[0100] - Applied in ascending order of the priority of the corresponding logical channel, and in ascending order of the LCID of the primary cell group in the case of the same priority

[0101] As a result of receiving a packet duplication activation / deactivation message, the UE may determine the (multiple) RLC entities of the DRB to be used for packet duplication transmission and perform packet duplication transmission.

[0102] All RLC entities set in the DRB may have an Li field. In this case, in the Figure 3 radio bearer, all four RLC entities may have an Li field, and each of the four RLC entities may be set with respect to whether to be used for packet duplication transmission. According to another embodiment, only the (multiple) RLC devices in which the ul_duplication field has been set to true as described above with reference to Figure 3 may have a corresponding Li field. In this case, in the Figure 3 radio bearer, three RLC entities in which the up_duplication field has been set to true may have an Li field and may be set with respect to whether to be used for packet duplication transmission.

[0103] Figure 8 Shows the format of a packet duplication activation / deactivation message according to another embodiment.

[0104] Refer to Figure 8, the packet duplication activation / deactivation message may have a MAC CE format. According to an embodiment, the packet duplication activation / deactivation message may include DRB IDs 1h-10 and Li (i = 1, 2, 3, 4, 5, 6, 7, 8) fields 1h-30, 1h-40, 1h-50, 1h-60, 1h-70, 1h-80, 1h-90, and 1h-100 corresponding to RLC entities. Additionally, in some cases, the packet duplication activation / deactivation message may include a reserved (R) bit 1h-20.

[0105] The Li fields 1h-30, 1h-40, 1h-50, 1h-60, 1h-70, 1h-80, 1h-90, and 1h-100 may represent the corresponding RLC entities. Additionally, each of the Li fields 1h-30, 1h-40, 1h-50, 1h-60, 1h-70, 1h-80, 1h-90, and 1h-100 may set whether to use the corresponding RLC entity for packet duplication transmission according to its bit value. For example, a value of 1 in the Li field may indicate that the corresponding RLC entity is used for packet duplication transmission, and a value of 0 in the Li field may indicate that the corresponding RLC entity is not used for packet duplication transmission. The Li field may indicate the RLC entity by using a preset value, which may be applied as one of the following values.

[0106] - Applied in ascending (descending) order of the LCIDs of the primary cell group, and then in ascending (descending) order of the LCIDs of the secondary cell group

[0107] - In ascending order of a preset index corresponding to the RLC entity

[0108] - Applied in ascending order of the priority of the corresponding logical channel, and in ascending order of the LCID of the primary cell group in the case of the same priority

[0109] As a result of receiving the packet duplication activation / deactivation message, the UE may determine the (multiple) RLC entities of the DRB to be used for packet duplication transmission and perform packet duplication transmission.

[0110] All RLC entities set in the DRB may have an Li field. In this case, in the Figure 3 radio bearer, all four RLC entities may have an Li field, and each of the four RLC entities may be set regarding whether to be used for packet duplication transmission. According to another embodiment of the present disclosure, only the RLC entities for which the up_duplication field has been set to true as described above with reference to Figure 3 may have an Li field. In this case, in the Figure 3Among the radio bearers, three RLC entities for which the up_duplication field has been set to true may have the Li field and may be set as to whether to be used for packet duplication transmission.

[0111] Figure 9 Shows the format of a packet duplication activation / deactivation message according to another embodiment.

[0112] Referring to Figure 9 , the packet duplication activation / deactivation message may have a MAC CE format. According to an embodiment, the packet duplication activation / deactivation message may include DRB ID 1i-10 and the number N dup field 1i-20 indicating the number of RLC entities to be used for uplink packet duplication. The DRB ID 1i-10 may represent the ID of the DRB to which the activation / deactivation of packet duplication transmission is to be applied. The UE may receive the MAC CE and then perform packet duplication transmission by using the RLC entity corresponding to the number set in the N dup field 1i-20. The RLC entity to be used for packet duplication transmission among the RLC entities set for the UE may be selected by a preset method as one of the following methods.

[0113] - Apply in ascending (descending) order of the LCIDs of the primary cell group, and then apply in ascending (descending) order of the LCIDs of the secondary cell group to select N dup RLC entities

[0114] - Select N dup RLC entities in ascending order of the preset index corresponding to the RLC entity

[0115] - Apply in ascending order of the priority of the corresponding logical channel, and select N dup RLC entities in ascending order of the LCID of the primary cell group in the case of the same priority

[0116] As a result of receiving the packet duplication activation / deactivation message, the UE may determine the (multiple) RLC devices of the DRB to be used for packet duplication transmission and perform packet duplication transmission.

[0117] Figure 10 Shows the format of a packet duplication activation / deactivation message according to another embodiment.

[0118] Referring to Figure 10 , the packet duplication activation / deactivation message may have a MAC CE format. The format of the packet duplication activation / deactivation message shown in Figures 7 to 9 has been described to indicate the activation / deactivation of packet duplication of a radio bearer. However, the message may be used to set the packet duplication of multiple radio bearers.

[0119] exist Figure 10 In the above reference Figure 7 The three messages 1j-10, 1j-20 and 1j-30, each of which includes a DRB index and a format of a Li field corresponding to an RLC entity, may overlap to construct a MAC CE. However, this is only an example, and the number of overlapping MAC CEs is not limited. The number of overlapping MAC CEs may have been set in advance, may correspond to the number of radio bearers for which packet duplication has been set, or may be variably determined for the radio bearers for which the base station intends to set packet duplication. When a variable size MAC CE format is used, it may be necessary to include the L field (length field) of the MAC subheader.

[0120] In this case, packet duplication may be allowed for the RLC entity of the radio bearer indicated by the DRB index.In addition, the DRB index may be a preset value, which may be applied as one of the following values.

[0121] - Specified in DRM configuration according to the base station settings

[0122] - Applied in ascending order of DRB IDs of the radio bearers for which packet duplication has been set

[0123] - Applied by the MAC entity that has sent the MAC ME in ascending order of the DRB IDs of the radio bearers for which the RLC entity exists and for which packet duplication has been set up

[0124] -DRB ID value

[0125] The Li field may indicate a corresponding RLC entity, and each of the Li fields may set whether to use the corresponding RLC entity for packet copy transmission according to its bit value. For example, a value of 1 in the Li field may indicate that the corresponding RLC entity is used for packet copy transmission, and a value of 0 in the Li field may indicate that the corresponding RLC entity is not used for packet copy transmission. The Li field may indicate an RLC entity by using a preset value, which may be applied as one of the following values.

[0126] - Applied in ascending (descending) order of LCID of primary cell group and then in ascending (descending) order of LCID of secondary cell group

[0127] - In ascending order of the preset index corresponding to the RLC entity

[0128] - Applied in ascending order of priority of the corresponding logical channels, and in ascending order of LCID of the primary cell group in case of the same priority.

[0129] As a result of receiving a packet duplication activation / deactivation message, the UE may determine the (multiple) RLC entities of the DRB to be used for packet duplication transmission and perform packet duplication transmission.

[0130] All RLC entities set in the DRB may have the Li field. In this case, in the Figure 3 radio bearer, all four RLC entities may have the Li field, and each of the four RLC entities may be set as to whether it is used for packet duplication transmission. According to another embodiment, the (multiple) RLC devices in which the ul_duplication field as described above with reference to Figure 3 has been set to true may have a corresponding Li field. In this case, in the Figure 3 radio bearer, the three RLC entities in which the up_duplication field has been set to true may have the Li field and may be set as to whether they are to be used for packet duplication transmission.

[0131] Figure 10 The format of the message shown in Figure 7 is the same as the MAC CE format shown in Figure 8 or Figure 9 shown. However, the message format shown in

[0132] Figure 11 may be used. In addition, a packet duplication activation / deactivation message for a general single radio bearer may be used.

[0132] Figure 11 is a diagram showing a method by which the UE notifies the base station whether the UE has a packet duplication activation function according to an embodiment.

[0133] Since packet duplication transmission is used to reduce latency or improve reliability, such as the packet loss probability, a specific UE may support such a packet duplication transmission function. In this case, the UE may notify the base station whether the UE supports the packet duplication transmission function. At this time, the UE may include information on whether it supports the packet duplication transmission function in the UE capability message 1k-10. In addition, the UE capability message 1k-10 may include at least one piece of information related to the packet duplication transmission of the UE. This information may be as follows.

[0134] - The maximum number of RLC entities that can perform packet duplication in a single radio bearer

[0135] - The maximum number of RLC entities that can be set in a single radio bearer

[0136] - Whether packet duplication transmission using three or more RLC entities is supported

[0137] - The maximum number of radio bearers that can be set with group copy transmission using three or more RLC entities can be configured.

[0138] Figure 12 FIG. is a diagram showing an operation of performing group copy transmission according to an embodiment.

[0139] Referring to Figure 12 , multiple RLC entities can be set for a radio bearer, and the RLC entities can be configured with a primary RLC entity and secondary RLC entities, as Figure 1 shown. In this case, in response to the activation of group copy, the UE can determine the (multiple) RLC devices for which group copy will be set.

[0140] In operation 1l-10, when group copy for a certain radio bearer is set, the process can proceed to operation 1l-20 to determine whether the group copy transmission for the corresponding bearer has been actually activated.

[0141] When it is determined that the group copy transmission has been actually activated, the process can proceed to operation 1l-30, such that the transmitter PDCP entity can copy the packets and send the copied packets to the pre-set primary RLC entity and all secondary RLC entities.

[0142] When it is determined that the group copy transmission has not been actually activated, the process can proceed to operation 1l-40, such that the transmitter PDCP entity can send the packets to the primary RLC entity without copying the packets.

[0143] In the case of applying a split bearer, when the data to be sent is less than or equal to (or less than) a specific threshold, the transmitter PDCP entity can send the packets only to the primary RLC entity, and when the data is greater than (or greater than or equal to) the specific threshold, the transmitter PDCP entity can send the packets to all primary RLC entities and secondary RLC entities. However, when it is determined that the group copy transmission has not been actually activated, the transmitter PDCP entity can refrain from copying the packets.

[0144] Figure 13 FIG. is a block diagram showing the internal structure of a UE according to an embodiment.

[0145] Referring to Figure 13 , the UE can include a transceiver 1m-10, a memory 1m-20, and a processor 1m-30. The transceiver 1m-10, memory 1m-20, and processor 1m-30 of the UE can operate according to the UE's communication method as described above. However, the components of the UE are not limited to the above components. For example, the UE can include more or fewer components than those described above. Additionally, the transceiver 1m-10, memory 1m-20, and processor 1m-30 can be implemented in the form of a single chip.

[0146] The transceiver 1m-10 can send signals to and receive signals from another network entity (e.g., a base station). Herein, the signals can include control information and data. To send and receive signals, the transceiver 1m-10 can be configured with an RF transmitter and an RF receiver. The RF transmitter is used to up-convert the frequency of the signal to be sent and amplify the signal, and the RF receiver is used to perform low-noise amplification of the received signal and down-convert the frequency of the received signal. However, the RF transmitter and the RF receiver are examples of the transceiver 1m-10, and the components of the transceiver 1m-10 are not limited to the RF transmitter and the RF receiver.

[0147] In addition, the transceiver 1m-10 can receive signals through a wireless channel, output the signals to the processor 1m-30, and send the signals output from the processor 1m-30 through the wireless channel. For example, the transceiver 1m-10 can receive system information from a base station and receive a synchronization signal or a reference signal.

[0148] The memory 1m-20 can store programs and data required for the operation of the UE. In addition, the memory 1m-20 can store control information or data included in the signals obtained by the UE. For example, the memory 1m-20 can store the information sent / received through the transceiver 1m-10 and the information generated by the processor 1m-30. The memory 1m-20 can be configured with a storage medium (such as a read-only memory (ROM), a random access memory (RAM), a hard disk, a compact disc read-only memory (CD-ROM), and a digital versatile disc (DVD)) or a combination of storage media.

[0149] The processor 1m-30 can control a series of processes so that the UE operates according to the above embodiments. For example, the processor 1m-30 can control the signal flow between blocks to perform operations according to the above flowcharts. In addition, the processor 1m-30 can include a circuit or an application-specific integrated circuit.

[0150] Figure 14 is a block diagram showing the configuration of a base station according to an embodiment.

[0151] Referring to Figure 14 , the base station can include a transceiver 1n-10, a memory 1n-20, and a processor 1n-30. As described above, the transceiver 1n-10, the memory 1n-20, and the processor 1n-30 of the base station can operate according to the communication method of the base station. However, the components of the base station are not limited to the above components. For example, the base station can include more or fewer components than the above components. The transceiver 1n-10, the memory 1n-20, and the processor 1n-30 can be implemented in the form of a single chip.

[0152] The transceiver 1n-10 can send signals to another network entity (e.g., UE) and receive signals from another network entity (e.g., UE). The signals can include control information and data. To send and receive signals, the transceiver 1n-10 can be configured with an RF transmitter and an RF receiver. The RF transmitter is used to up-convert the frequency of the signal to be sent and amplify the signal, and the RF receiver is used to low-noise amplify the received signal and down-convert the frequency of the received signal. However, the RF transmitter and the RF receiver are examples of the transceiver 1n-10, and the components of the transceiver 1n-10 are not limited to the RF transmitter and the RF receiver.

[0153] In addition, the transceiver 1n-10 can receive signals through a wireless channel, output the signals to the processor 1n-30, and send the signals output from the processor 1n-30 through the wireless channel. For example, the transceiver 1n-10 can send system information to the UE and send a synchronization signal or a reference signal to the UE.

[0154] The memory 1n-20 can store programs and data required for the operation of the base station. In addition, the memory 1n-20 can store control information or data included in the signals acquired by the base station. For example, the memory 1n-20 can store information sent / received through the transceiver 1n-10 and information generated by the processor 1n-30. The memory 1n-20 can be configured with a storage medium (such as ROM, RAM, hard disk, CD-ROM, and DVD) or a combination of storage media.

[0155] The processor 1n-30 can control a series of processes so that the base station operates according to the above embodiments of the present disclosure. In addition, the processor 1n-30 can include a circuit or an application-specific integrated circuit.

[0156] Figure 15 The structure of a radio bearer provided with packet duplicate transmission according to another embodiment is shown.

[0157] Packet duplicate transmission means duplicating packets and sending the duplicated packets to multiple paths at the transmitter.

[0158] Referring to Figure 15 , in the radio bearer structure according to the embodiment, four RLC entities RLC12a-20, RLC2 2a-30, RLC3 2a-40, and RLC4 2a-50 are connected to the PDCP entity PDCP1 2a-10 to support multiple paths. However, the radio bearer structure is only an example, and the number of RLC entities connected to the PDCP entity is not limited. In addition, the base station can set the radio bearer structure according to the radio link and the network structure.

[0159] In a radio bearer structure according to an embodiment, the layer that performs packet duplication may be the PDCP entity 2a-10, and the PDCP entity 2a-10 may perform packet duplication and then send the duplicated packets to two or more different RLC entities, enabling the RLC entities to independently perform packet transmission. Since the radio bearer includes the PDCP entity regardless of packet duplication, the PDCP entity may correspond to the radio bearer ID. According to an embodiment, the radio bearer including the PDCP entity PDCP1 2a-10 may be a DRB or an SRB.

[0160] The RLC entities RLC1 2a-20, RLC2 2a-30, RLC3 2a-40, and RLC4 2a-50 may be classified into a primary RLC entity 2a-20 and secondary RLC entities 2a-30, 2a-40, and 2a-50 according to their uses. Regardless of the activation of packet duplication, the primary RLC entity 2a-20 may always perform packet transmission. In addition, the secondary RLC entities 2a-30, 2a-40, and 2a-50 may perform packet transmission in response to the activation of packet duplication. Additionally, according to the setting method, the secondary RLC entities 2a-30, 2a-40, and 2a-50 may not participate in uplink packet transmission.

[0161] In the case of applying a split bearer, when the data to be sent is less than or equal to (or less than) a specific threshold, the transmitter may send the packet only to the primary RLC entity, and when the data is greater than (or greater than or equal to) the specific threshold, the transmitter may send the packet to all the primary RLC entities and the secondary RLC entities.

[0162] Packet duplication transmission may be used for the purpose of increasing the transmission probability by sending packets of the same information to different paths. Therefore, in the case of sending packets to be sent to different RLC entities into the same MAC PDU, the effect may not be obtained. Therefore, by restricting the cells available to the RLC entities, it is possible to prevent packets to be sent to different RLC entities from being sent to the same MAC PDU.

[0163] Refer to Figure 15, the RLC entity RLC1 2a-20 can use only cell 1 2a-60, the RLC entity RLC2 2a-30 can use only cell 2 2a-70 and cell 3 2a-80, the RLC entity RLC3 2a-40 can use only cell 4 2a-90, and the RLC entity RLC4 uses only cell 5 2a-100. Each RLC entity can be mapped to a logical channel, and when a logical channel is established, a list of cells available for the logical channel can be set. The list of cells available for each logical channel is called a cell restriction. The cell restriction can be applied by the following method, in which, after the UE is allocated uplink resources, the RLC entity corresponding to the logical channel configured to use the corresponding cell in the logical channel priority (LCP) operation participates in the cell restriction.

[0164] Settings regarding the above detailed operations can be included in at least one of the RLC configurations in the radio bearer configuration, RLC bearer configuration, PDCP configuration, and RRC configuration messages, and sent to the UE.

[0165] Figure 16 is a diagram showing a method for activating and deactivating control packet replication performed by a base station according to another embodiment.

[0166] Packet replication transmission may increase the consumption of radio resources because the same packet is sent using two or more RLC entities. Therefore, packet replication transmission may result in low radio resource utilization efficiency. Therefore, it may not be preferable to always perform packet replication. Therefore, it may be preferable to perform packet replication transmission as needed. Enabling packet replication to be actually performed in a radio bearer where packet replication has been set is called activation of packet replication. On the contrary, disabling packet replication from being performed in a radio bearer where packet replication has been set is called deactivation of packet replication.

[0167] In operation 2b-10, the base station can send a packet replication activation / deactivation message to the UE. At this time, a message with the same format can be used for activation and deactivation, and the activation and deactivation of packet replication can be distinguished by the value included in the message. The packet replication activation / deactivation message can indicate which radio bearer to activate or deactivate for packet replication.

[0168] In operation 1b-20, after the UE receives the packet replication activation / deactivation message, the UE can activate or deactivate packet replication according to the indication included in the packet replication activation / deactivation message.

[0169] The packet replication activation / deactivation message can update the packet replication status in the RRC configuration, or can be sent in the form of a packet replication activation / deactivation MAC CE.

[0170] Figure 17 Shows a method for controlling activation and deactivation in carrier aggregation of cells performed by a base station according to an embodiment.

[0171] When two or more cells are used in carrier aggregation, the UE may need to continuously use the transceivers of the cells, which increases power consumption. Therefore, when the UE does not need to use multiple cells, the base station can deactivate the cells of the UE. Additionally, when a specific cell is not used for data transmission / reception within a predefined time period, the base station can determine that the corresponding cell is not needed and deactivate the cell.

[0172] In operation 2c-1, the base station can send a cell activation / deactivation message to the UE to activate / deactivate some cells. In both the activation / deactivation performed by the base station through message transmission and the deactivation performed by the determination of the UE, the UE can participate in the activation and deactivation of SCell that is essential for the connection to the base station rather than PCell or PSCell.

[0173] In operation 2c-20, when the UE receives a cell activation / deactivation message within a predefined time period or does not use a specific cell for transmission / reception, the UE can apply the activation / deactivation of the cell.

[0174] Figure 18 Is a diagram for describing a method of applying cell configuration when packet duplication transmission is deactivated according to an embodiment.

[0175] Referring to Figure 18 , when packet duplication transmission is deactivated by a packet duplication activation / deactivation message, the transmitter PDCP entity 2d-10 may no longer need to duplicate packets and transmit the duplicated packets to multiple RLC entities. The transmitter PDCP 2d-10 can transmit the packets to be sent to the primary RLC 2d-20, or can transmit the packets to one of the RLC entities 2d-20, 2d-30, 2d-40, and 2d-50 defined by split bearer operation. When the UE does not perform packet duplication transmission, it may not be necessary to apply the list of cells available to each RLC entity described above with reference to Figure 15 Therefore, when the packet duplication transmission of a radio bearer for which packet duplication has been set is deactivated, all RLC entities of the corresponding radio bearer can use all the cells 2d-60, 2d-70, 2d-80, 2d-90, and 2d-100 set in advance without applying the restrictions of the cell list, as described above with reference to Figure 18 That is to say, the cell restrictions can be not applied.

[0176] Cell restriction may be applied or not applied in units of RLC entities (in other words, in units of logical channels) or in units of radio bearers to which packet duplication has been applied. According to an embodiment, when applying cell restriction in units of RLC units, it may be determined whether to apply cell restriction based on whether packet duplication of the corresponding RLC entity has been activated. That is, cell restriction may be applied only when the corresponding RLC entity is used for packet duplication transmission. Otherwise, cell restriction may not be applied. According to an embodiment, when applying cell restriction in units of radio bearers, packet duplication transmission of all secondary RLC entities belonging to the corresponding radio bearer may be deactivated. In this case, cell restriction may not be applied. In addition, when only one RLC entity to be used for packet duplication is set or activated, packet duplication transmission may be impossible. In this case, cell restriction may not be applied. According to another embodiment, when the base station sends a packet duplication activation / deactivation message to deactivate the packet duplication transmission of the corresponding radio bearer, cell restriction may not be applied. Additionally, when the number of logical channels among the logical channels of the radio bearer for which packet duplication has been set and for which packet duplication has been activated within the same cell group is one or less, cell restriction may not be applied.

[0177] Figure 19 is a diagram showing a method for applying cell restriction to packet duplication according to an embodiment.

[0178] In operation 2e-10, when packet duplication is set in a radio bearer and cell restriction for each logical channel is set, the UE may need to determine whether to apply cell restriction to the RLC entity.

[0179] In operation 2e-20, the UE may determine whether packet duplication of all secondary RLC entities has been deactivated. The UE may determine whether to apply cell restriction to the RLC entity based on this determination.

[0180] When packet duplication of all secondary RLC entities has been deactivated, in operation 2e-30, the UE may send packets to all cells set in the cell group without applying cell restriction.

[0181] When packet duplication of a certain secondary RLC entity has been activated, cell restriction may be required. Therefore, the process may proceed to operation 2e-30 to apply cell restriction.

[0182] In Figure 19 DRB has been described as an example, however, the same operations can also be applied to SRB.

[0183] Figure 20 is a diagram for describing operations for deactivating cells in a bearer for which packet duplication has been set according to an embodiment.

[0184] Reference Figure 20 , assuming and describing the above reference Figure 15 Cell restriction and radio bearer for packet duplication described above. As described above, for packet duplication transmission, a list of cells available for each logical channel, i.e., cell restriction, can be set, and each RLC entity can participate in LCP operation only for cells that it can use to send packets. However, when all cells set as available for a logical channel are deactivated by a deactivation message or the like, the corresponding RLC entity cannot transmit any packets.

[0185] According to an embodiment, when cell 4 2f-90 set to be available to RLC3 2f-40 is deactivated, RLC3 2f-40 may not have a cell through which packets can be transmitted. Therefore, in this case, the transmitter PDCP entity 2f-10 may no longer transmit packets to RLC3 2f-40. In addition, the transmitter PDCP entity 2f-10 may indicate that packets waiting for transmission in RLC3 2f-40 are discarded. However, in some cases, RLC3 2f-40 may maintain packets for retransmission. Packets can continue to be retransmitted without being applied to cell restrictions. According to an embodiment, RLC3 2f-40 can be reestablished. This operation may be the same as an operation not used in packet replication of RLC3 2f-40 (i.e., a packet replication deactivation operation of RLC3 2f-40).

[0186] Figure 21 is a diagram illustrating an operation of performing packet duplication in a transmitter PDCP entity according to an embodiment.

[0187] As mentioned above Figure 20 As described, the cells available to each RLC device, in other words, the logical channels may be deactivated and thus unavailable. In this case, the packet duplication operation of the transmitter PDCP entity may be changed.

[0188] In operation 2g-10, when the packet duplication of the radio bearer is set and activated, the process may proceed to operation 2g-20, and the transmitter PDCP entity may check whether the RLC entity to be used for packet duplication has at least one activated cell, and transmit the duplicated packet to the RLC entity having at least one activated cell. Through this operation, the RLC entity that does not have a cell to be used may be prevented from performing data processing operations unnecessarily.

[0189] Figure 22 is a diagram for describing an operation of packet duplication transmission deactivation according to a specific RLC entity in a bearer configured with packet duplication according to an embodiment.

[0190] ReferenceFigure 22 Assume the cell restrictions and radio bearers for packet duplication described above with reference to Figure 15 . When a specific one of the RLC entities that are set such that the UE can participate in packet duplication is deactivated, the cells available for the corresponding logical channel may no longer transmit data. Thus, not using some of the active cells may result in consumption of radio resources. Therefore, it may be effective to have other cells of the same radio bearer use these cells.

[0191] According to an embodiment, assume a case where packet duplication of RLC2 2h-30 is deactivated (2h-110). In other words, RLC2 2h-30 may not participate in packet duplication transmission, and the transmitter PDCP entity may not send any duplicated packets to RLC2 2h-30. In this case, cells 2 2h-70 and 3 2h-80 that are set to be available for RLC2 2h-30 may be used by another RLC device. According to an embodiment, the RLC entity that will use the cells available for the deactivated RLC entity may change. For example, the primary RLC entity may use the cells available for the deactivated RLC device. In addition, among different secondary RLC entities in the same cell group, the RLC entity having the highest or lowest logical channel ID may use the cells available for the deactivated RLC device. Further, after the RLC entity is deactivated by RRC configuration in the base station, the RLC entity may be configured to use the cells of the deactivated RLC entity.

[0192] Figure 23 is a diagram for describing an operation of applying cell restrictions when applying two or more cell groups according to an embodiment.

[0193] With reference to Figure 23 assume the cell restrictions and radio bearers for packet duplication described above with reference to Figure 15 . In a dual-connectivity structure, the connection to multiple base stations may be performed in units of cell groups. That is, a cell group may include at least one cell and correspond to a MAC entity and a base station. In this case, logical channels belonging to different cell groups, that is, RLC entities belonging to different cell groups may not perform transmission together because the RLC entities use different MAC entities. When only one RLC entity performs packet duplication in a cell group, the cell restrictions as shown in Figure 23 may not need to be maintained for packet duplication. Therefore, when the number of RLC entities for packet duplication in the same cell group is one or less despite activation of packet duplication transmission of the radio bearer, the cell restrictions may not be applied.

[0194] According to an embodiment, RLC1 2i-20 and RLC2 2i-30 may operate in cell group 1 2i-110, where RLC1 2i-20 may use cell 1 2i-60, and RLC2 2i-30 may use cell 2 2i-70 and cell 3 2i-80. RLC3 2i-40 and RLC4 2i-50 may operate in cell group 2 2i-120, where RLC3 2i-40 may use cell 4 2i-90, and RLC4 2i-50 may use cell 5 2i-100. For example, when RLC3 2i-40 is not used for packet duplication transmission and RLC4 2i-50 is used for packet duplication transmission through RRC configuration or activation / deactivation settings, RLC4 2i-50 may use both cell 5 2i-100 and cell 4 2i-90 set to cell group 2 2i-120, rather than only using cell 5 2i-100 available to itself.

[0195] Figure 24 is a block diagram showing the internal structure of a UE according to another embodiment.

[0196] Referring to Figure 24 , the UE may include a transceiver 2j-10, a memory 2j-20, and a processor 2j-30. The transceiver 2j-10, memory 2j-20, and processor 2j-30 of the UE may operate according to the communication method of the UE as described above. However, the components of the UE are not limited to the above components. For example, the UE may include more or fewer components than the above components. In addition, the transceiver 2j-10, memory 2j-20, and processor 2j-30 may be implemented in the form of a single chip.

[0197] The transceiver 2j-10 may send signals to another network entity (e.g., a base station) and receive signals from another network entity (e.g., a base station). Here, the signals may include control information and data. To send and receive signals, the transceiver 2j-10 may be configured with an RF transmitter and an RF receiver. The RF transmitter is used to up-convert the frequency of the signal to be sent and amplify the signal, and the RF receiver is used to low-noise amplify the received signal and down-convert the frequency of the received signal. However, the RF transmitter and the RF receiver are embodiments of the transceiver 2j-10, and the components of the transceiver 2j-10 are not limited to the RF transmitter and the RF receiver.

[0198] In addition, the transceiver 2j-10 may receive signals through a wireless channel, output the signals to the processor 2j-30, and send the signals output from the processor 1m-30 through the wireless channel. For example, the transceiver 2j-10 may receive system information from a base station and receive a synchronization signal or a reference signal.

[0199] The memory 2j-20 may store programs and data required for the operation of the UE. Additionally, the memory 2j-20 may store control information or data included in signals obtained by the UE. For example, the memory 2j-20 may store information transmitted / received through the transceiver 2j-10, as well as information generated by the processor 2j-30. The memory 2j-20 may be configured with a storage medium (such as ROM, RAM, hard disk, CD-ROM, and DVD) or a combination of storage media.

[0200] The processor 2j-30 may control a series of processes such that the UE operates according to the above-described embodiments of the present disclosure. For example, the processor 2j-30 may control the signal flow between blocks to perform operations according to the above flowcharts. Additionally, the processor 2j-30 may include a circuit or an application-specific integrated circuit.

[0201] Figure 25 is a block diagram showing the configuration of a base station according to another embodiment.

[0202] Referring to Figure 25 , the base station may include a transceiver 2k-10, a memory 2k-20, and a processor 2k-30. The transceiver 2k-10, memory 2k-20, and processor 2k-30 of the base station may operate according to the communication method of the base station described above. However, the components of the base station are not limited to the above components. For example, the base station may include more or fewer components than the above components. The transceiver 2k-10, memory 2k-20, and processor 2k-30 may be implemented in the form of a single chip.

[0203] The transceiver 2k-10 may send signals to another network entity (e.g., UE) and receive signals from another network entity (e.g., UE). The signals may include control information and data. To send and receive signals, the transceiver 2k-10 may be configured with an RF transmitter and an RF receiver. The RF transmitter is used to up-convert the frequency of the signal to be sent and amplify the signal, and the RF receiver is used to low-noise amplify the received signal and down-convert the frequency of the received signal. However, the RF transmitter and RF receiver are embodiments of the transceiver 2k-10, and the components of the transceiver 2k-10 are not limited to the RF transmitter and RF receiver.

[0204] Additionally, the transceiver 2k-10 may receive signals through a wireless channel, output the signals to the processor 2k-30, and send the signals output from the processor 2k-30 through the wireless channel. For example, the transceiver 2k-10 may send system information to the UE and send a synchronization signal or a reference signal to the UE.

[0205] The memory 2k-20 can store programs and data required for the operation of the base station. Additionally, the memory 2k-20 can store control information or data included in signals acquired by the base station. For example, the memory 2k-20 can store information transmitted / received through the transceiver 2k-10 and information generated by the processor 2k-30. The memory 2k-20 can be configured with a storage medium (such as ROM, RAM, hard disk, CD-ROM, and DVD) or a combination of storage media.

[0206] The processor 2k-30 can control a series of processes such that the base station operates according to the above embodiments of the present disclosure. In addition, the processor 2k-30 can include a circuit or an application-specific integrated circuit.

[0207] Figure 26 The format of a packet duplication activation / deactivation message according to another embodiment is shown.

[0208] Referring to Figure 26 , the packet duplication activation / deactivation message can have a MAC CE format. According to an embodiment, the packet duplication activation / deactivation message can include a DRB index 1o-10 and Li (i = 1, 2, 3, 4, 5) fields 1o-20, 1o-30, 1o-40, and 1o-50 corresponding to RLC entities. The DRB index 1o-10 can be a preset value, which can be applied as one of the following values.

[0209] - Specified in the DRM configuration according to the settings of the base station

[0210] - Applied in ascending order of the DRB ID of the radio bearer for which packet duplication has been set

[0211] - Applied in ascending order of the DRB ID of the radio bearer for which there is an RLC entity and packet duplication has been set by the MAC entity that has sent the MAC ME

[0212] - The DRB ID value

[0213] The Li fields 1o-20, 1o-30, 1o-40, and 1o-50 can represent the corresponding RLC entities, and each of the Li fields 1o-20, 1o-30, 1o-40, and 1o-50 can set whether to use the corresponding RLC entity for packet duplication transmission according to its bit value. For example, a value of 1 in the Li field can represent that the corresponding RLC entity is used for packet duplication transmission, and a value of 0 in the Li field can represent that the corresponding RLC entity is not used for packet duplication transmission. The Li field can indicate the RLC entity by using a preset value, which can be applied as one of the following values.

[0214] -Apply in ascending (descending) order of the LCIDs of the primary cell group and then in ascending (descending) order of the LCIDs of the secondary cell group

[0215] -In ascending order of the preset index corresponding to the RLC entity

[0216] -Apply in ascending order of the priorities of the corresponding logical channels, and in ascending order of the LCIDs of the primary cell group in the case of the same priority

[0217] As a result of receiving the packet duplication activation / deactivation message, the UE can determine the RLC device(s) of the DRB to be used for packet duplication transmission and perform packet duplication transmission.

[0218] All RLC entities set in the DRB can have the Li field. In this case, in the Figure 3 radio bearer, all four RLC entities can have the Li field, and each of the four RLC entities can be set regarding whether it is used for packet duplication transmission. According to another embodiment, only the RLC device(s) in which the ul_duplication field has been set to true as described above with reference to Figure 3 can have the corresponding Li field. In this case, in the Figure 3 radio bearer, the three RLC entities in which the up_duplication field has been set to true can have the Li field and can be set regarding whether they are to be used for packet duplication transmission.

[0219] According to another embodiment, the number of RLC entities set in the DRB in which packet duplication transmission has been set can be the same as the number of Li fields. In the Figure 26 embodiment, four Li fields 1o-20, 1o-30, 1o-40, and 1o-50 have been set. Setting the four Li fields can indicate a state where the number of RLC entities set in the corresponding DRB is 4. For example, when the number of RLC entities set in the corresponding DRB is 3, Li fields L1, L2, and L3 can be provided. Then, a reserved (R) field 1o-60 can be included to fill the byte length. This means filling the R bits such that Figure 26 the length of the packet duplication activation / deactivation message shown in is the byte length, i.e., a multiple of 8 bits. The value of the R bits can be set to a predefined value, or the UE can ignore the predefined value.

[0220] In a dual-connectivity configuration, it is not necessary to indicate in the packet duplication activation / deactivation message sent to a specific cell group whether all RLC entities are used for packet duplication transmission. For example, the MAC CE sent to the master cell group (MCG) may indicate whether only the RLC entities configured in the MCG are used for packet duplication transmission. In this case, the number of Li fields may be the same as the number of RLC entities whose use for packet duplication transmission in the corresponding MAC CE is indicated. For example, in a radio bearer for which packet duplication transmission has been configured, when the number of RLC entities configured in the MCG is 2, the number of Li fields may be 2, and the remaining fields may be R fields.

[0221] According to another embodiment, the Li field may be set to the maximum number of RLC entities configurable for each radio bearer, and it may be determined whether the actually configured RLC entities are used for packet duplication based on the actual Li fields. For example, when four RLC entities are actually configurable, four Li fields L1 1o-10, L2 1o-20, L3 1o-30, and L4 1o-40 may be provided. When the number of actually configured RLC entities is 3, the Li fields L1 1o-10, L2 1o-20, and L3 1o-30 may be used to indicate whether the corresponding RLC entities are used for packet duplication transmission. Since the Li field L4 does not have a corresponding RLC device, the Li field L4 may be set to a predefined value of 0 or 1, and the UE may ignore this predefined value.

[0222] Since Figure 26 the packet duplication activation / deactivation message has a fixed size of 1 byte, the packet duplication activation / deactivation message may be a fixed-size MAC CE. In this case, the fixed-size MAC CE may have a MAC sub-header for the fixed-size MAC CE, which will be described later with reference to Figure 30 this.

[0223] Figure 27 Fig. shows the format of the packet duplication activation / deactivation message according to another embodiment.

[0224] Referring to Figure 27 this, the packet duplication activation / deactivation message may have a MAC CE format. In Figure 27 this, as referred to in Figure 26The three messages 1p-10, 1p-20, and 1p-30, each having a DRB index, an Li field corresponding to an RLC entity, and an R field as a reserved field for padding the byte length, may overlap to construct a MAC CE. However, this is only an example, and the number of overlapping MAC CEs is not limited. The number of MAC CEs to be overlapped may be variably determined by the base station for the radio bearers for which the base station intends to set packet duplication. When included in Figure 27 the packet duplication activation / deactivation message and the number of radio bearers controlling packet duplication transmission is variable, a variable-size MAC CE may be used. In this case, the variable-size MAC CE may have a MAC sub-header for the variable-size MAC CE, which will be described with reference to Figure 29 . However, embodiments of the application method for the Li field and the R field may be the same as the example described above with reference to Figure 26 .

[0225] In this case, packet duplication of the RLC entity of the radio bearer indicated by the DRB index may be allowed. The DRB index may be a preset value, which may be applied as one of the following values.

[0226] - Specified in the DRM configuration according to the setting of the base station

[0227] - Applied in ascending order of the DRB IDs of the radio bearers for which packet duplication has been set

[0228] - Applied by the MAC entity that has sent the MAC ME in ascending order of the DRB IDs of the radio bearers for which there are RLC entities and packet duplication has been set

[0229] - DRB ID value

[0230] The Li field may represent the corresponding RLC entity, and each Li field may be set according to its bit value whether to use the corresponding RLC entity for packet duplication transmission. For example, a value of 1 in the Li field may indicate that the corresponding RLC entity is used for packet duplication transmission, and a value of 0 in the Li field may indicate that the corresponding RLC entity is not used for packet duplication transmission. The Li field may indicate the RLC entity by using a preset value, which may be applied as one of the following values.

[0231] - Applied in ascending (descending) order of the LCIDs of the primary cell group and then in ascending (descending) order of the LCIDs of the secondary cell group

[0232] - In ascending order of a preset index corresponding to the RLC entity

[0233] -Applied in ascending order of the priorities of the corresponding logical channels, and in ascending order of the LCIDs of the master cell group in the case of the same priority

[0234] As a result of receiving a packet duplication activation / deactivation message, the UE may determine the (multiple) RLC devices of the DRB that will be used for packet duplication transmission and perform packet duplication transmission.

[0235] All RLC entities set in the DRB may have an Li field. In this case, in the Figure 3 radio bearer, all four RLC entities may have an Li field, and each of the four RLC entities may be set regarding whether it is used for packet duplication transmission. According to another embodiment, only the (multiple) RLC devices for which the ul_duplication field has been set to true as described above with reference to Figure 3 may have a corresponding Li field. In this case, in the Figure 3 radio bearer, the three RLC entities for which the up_duplication field has been set to true may have an Li field and may be set regarding whether they are to be used for packet duplication transmission.

[0236] According to another embodiment, the number of RLC entities set in the DRB for which packet duplication transmission has been set may be the same as the number of Li fields. In the Figure 27 embodiment, four Li fields have been set for each of all radio bearers. This may indicate that the number of RLC entities set in the corresponding DRB is 4. For example, when the number of RLC entities set in the corresponding DRB is 3, Li fields L1, L2, and L3 may be provided. Then, a Reserved (R) field may be included to fill the byte length. This means filling the R bits such that Figure 27 the length of the packet duplication activation / deactivation message shown in is a byte length, i.e., a multiple of 8 bits. The value of the R bits may be set to a predefined value, or the UE may ignore the predefined value.

[0237] In a dual-connectivity structure, it may not be indicated in the packet duplication activation / deactivation message sent to a specific cell group whether all RLC entities are used for packet duplication transmission. For example, the MAC CE sent to the MCG may indicate whether only the RLC entities set in the MCG are used for packet duplication transmission. In this case, the number of Li fields may be the same as the number of RLC entities indicated as being used for packet duplication transmission in the corresponding MAC CE. For example, in a certain radio bearer for which packet duplication transmission has been set, when the number of RLC entities set in the MCG is 2, the number of Li fields may be 2, and the remaining fields may be R fields.

[0238] According to another embodiment, the Li field may be set to the maximum number of RLC entities that can be set for each radio bearer, and it may be determined whether to use the actually set RLC entities for packet duplication based on the actual Li field. For example, when four RLC entities are actually settable, four Li fields L1, L2, L3, and L4 may be provided. When the number of actually set RLC entities is 3, the Li fields L1, L2, and L3 may be used to indicate whether to use the corresponding RLC entities for packet duplication transmission. However, since the Li field L4 does not have a corresponding RLC device, the Li field L4 may be set to a predefined value of 0 or 1, and the UE may ignore this predefined value.

[0239] Figure 28 Shows the format of a packet duplication activation / deactivation message according to another embodiment.

[0240] Referring to Figure 28 , the packet duplication activation / deactivation message may have a MAC CE format. In Figure 28 , as referred to above with reference to Figure 26 , three messages 1q-10, 1q-20, and 1q-30 each having a DRB index and a Li field corresponding to an RLC entity as shown above may overlap to construct a MAC CE. However, this is only an example, and the number of overlapping MAC CEs is not limited. The number of MAC CEs to be overlapped may be variably determined by the base station for the radio bearers for which the base station intends to set packet duplication. When the number of radio bearers that are included in the packet duplication activation / deactivation message in Figure 28 and that will control packet duplication transmission is variable, a variable-size MAC CE may be used. In this case, the variable-size MAC CE may have a MAC sub-header for the variable-size MAC CE, which will be described in Figure 29 . However, the embodiments of the application method for the Li field and the R field may be the same as the example described above with reference to Figure 26 .

[0241] In the embodiment of Figure 28 , the reserved (R) fields 1q-40, 1q-41, and 1q-42 have been used in the last bit of the MAC CE to fill the byte length of the entire message. That is, the DRB index and the Li field may list the values of all radio bearers indicated in the corresponding packet duplication activation / deactivation message. Figure 28 The application method of the DRB index and the Li field shown in the embodiment is the same as that described above with reference to Figure 27 .

[0242] Figure 29Shows the MAC sub - header format of a variable - size MAC CE according to an embodiment. The MAC sub - header can be located in front of the MAC CE to notify the information included in the subsequent MAC CE. The variable - size MAC CE can mean a MAC CE with a non - fixed length. The MAC sub - header can include a Length (L) field 1r - 40 to notify the length of the subsequent MAC CE. Additionally, the MAC sub - header can have a Reserved (R) field 1r - 10, an F field 1r - 20, and an LCID field 1r - 30. The F field 1r - 20 can be a field for notifying the length of the L field 1r - 40. When the F field 1r - 20 is 0, this can indicate that the L field 1r - 40 is 1 byte, and when the F field 1r - 20 is 1, this can indicate that the L field 1r - 40 is 2 bytes. In Figure 29 the embodiment, the value of the F field 1r - 20 is 0, and the length of the L field 1r - 40 is 1 byte. The LCID field 1r - 30 can include a value representing the type of the subsequent MAC CE. When a packet duplication activation / de - activation message follows the LCID field 1r - 30, the LCID field 1r - 30 can have an LCID value representing the packet duplication activation / de - activation message.

[0243] Figure 30 Shows the MAC sub - header format of a fixed - size MAC CE according to an embodiment. The MAC sub - header can be located in front of the MAC CE to notify the information included in the subsequent MAC CE. The fixed - size MAC CE can mean a MAC CE with a fixed length. Therefore, the MAC sub - header of the fixed - size MAC CE may not need Figure 29 the L field 1r - 40 as shown. Thus, the MAC sub - header of the fixed - size MAC CE can include a Reserved (R) field 1s - 10, an F field 1s - 20, and an LCID field 1s - 30. The F field 1s - 20 can be a field for notifying the length of the L field. In Figure 30 the embodiment, the L field may not be needed. Therefore, the F field 1s - 20 can be set to the value 0, and the UE can ignore the F field 1s - 20. The LCID field 1s - 30 can be a value representing the type of the subsequent MAC CE. When a packet duplication activation / de - activation message follows the LCID field 1s - 30, the LCID field 1s - 30 can have an LCID value representing the packet duplication activation / de - activation message.

[0244] The method according to the embodiments of the present disclosure described in the claims or its specification can be implemented in hardware, software, or a combination of hardware and software.

[0245] When these methods are implemented in software, a computer-readable storage medium storing at least one program (software module) can be provided. The at least one program stored in the computer-readable storage medium can be configured to be executed by at least one processor within the electronic device. The at least one program can include instructions that cause the electronic device to execute the methods according to the embodiments of the present disclosure described in the claims or their specifications.

[0246] The program (software module or software) can be stored in a RAM, non-volatile memory including flash memory, ROM, electrically erasable programmable ROM (EEPROM), magnetic disk storage device, CD-ROM, DVD, or other types of optical storage device, and magnetic tape cartridges. Optionally, the program can be stored in a memory configured as a combination of partial or all memories. Multiple such memories can be included.

[0247] In addition, the program can be stored in an attachable storage device, which can be accessed through a communication network such as the Internet, intranet, local area network (LAN), wireless LAN (WLAN), or storage area network (SAN), or a communication network configured in combination. The storage device can access the device implementing the embodiments of the present disclosure through an external port. In addition, a separate storage device on the communication network can also access the device implementing the embodiments of the present disclosure.

[0248] In the embodiments of the present disclosure, the components included in the present disclosure are represented in singular or plural forms. However, for convenience, the singular or plural expression is selected to suit the presented situation, and the present disclosure is not limited to the singular or plural forms. The components represented in multiple forms can be configured as a single component, or the components represented in singular form can be configured as multiple components.

[0249] Meanwhile, the embodiments of the present disclosure disclosed in this specification and the drawings are intended to easily describe the technical content of the present disclosure and help understand specific examples of the present disclosure, rather than to limit the scope of the present disclosure. That is, it will be obvious to those skilled in the art that other modified examples can be implemented based on the technical spirit of the present disclosure. In addition, the embodiments can be combined and used as needed. For example, some parts of the embodiments of the present disclosure can be combined to operate the base station and the UE. In addition, the embodiments can operate in various communication systems, such as frequency division duplex long term evolution (FDD LTE) systems, time division duplex long term evolution (TDD LTE) systems, and 5G or NR systems, and other modified examples based on the technical concepts of the embodiments can be executable.

Claims

1. A terminal for controlling packet replication in a wireless communication system, the terminal comprising: Transceiver; and at least one processor, coupled to the transceiver and configured to: receive, from a base station, a duplicate activation / deactivation media access control (MAC) control element (CE) associated with a plurality of secondary radio link control (RLC) entities for a data radio bearer (DRB), and in a case where the duplicate activation / deactivation MAC CE associated with the plurality of secondary RLC entities for the DRB indicates duplicate activation of at least one of the plurality of secondary RLC entities for the DRB, duplicate a first packet data convergence protocol (PDCP) packet for the at least one secondary RLC entity, and deliver the first PDCP packet to a primary RLC entity and deliver the duplicated first PDCP packet to the at least one secondary RLC entity, wherein the duplicate activation / deactivation MAC CE associated with the plurality of secondary RLC entities for the DRB includes an identifier of the DRB and a plurality of RLC fields regarding the DRB, and wherein an RLC field among the plurality of RLC fields regarding the DRB corresponds to a secondary RLC entity among the plurality of secondary RLC entities and indicates an activation or deactivation state of PDCP duplication regarding the secondary RLC entity corresponding to the RLC field.

2. The terminal according to claim 1, wherein, The at least one processor is further configured to: send, to the base station, capability information indicating whether duplicate transmission is supported by using more than two RLC entities.

3. The terminal according to claim 1, wherein, The at least one processor is further configured to: receive, from the base station via radio resource control (RRC) signaling, duplicate configuration information including duplicate status information of PDCP regarding a plurality of secondary RLC entities; identify, based on the duplicate configuration information, at least one RLC entity for packet duplicate transmission from among the plurality of secondary RLC entities; and duplicate a second PDCP packet for the identified at least one RLC entity and deliver the duplicated second PDCP packet to the identified at least one RLC entity.

4. The terminal according to claim 3, wherein, The duplicate configuration information includes a plurality of duplicate fields corresponding to the plurality of secondary RLC entities, wherein, in a case where a first duplicate field among the plurality of duplicate fields is set to "true", PDCP duplication for a secondary RLC entity corresponding to the first duplicate field is activated, and in a case where the first duplicate field is set to "false", PDCP duplication for a secondary RLC entity corresponding to the first duplicate field is deactivated.

5. The terminal according to claim 3, wherein, A corresponding RLC entity for PDCP duplication is designated based on a logical channel identifier (ID) of the plurality of secondary RLC entities.

6. The terminal according to claim 1, wherein, The plurality of RLC fields regarding the DRB are identified in ascending order of the logical channel ID in a primary cell group (MCG) and a secondary cell group (SCG).

7. The terminal according to claim 1, wherein, The at least one processor is further configured to: activate PDCP duplication of a secondary RLC entity corresponding to the RLC field in a case where the RLC field is set to 1, and deactivate PDCP duplication of a secondary RLC entity corresponding to the RLC field in a case where the RLC field is set to 0.

8. The terminal according to claim 1, wherein, The primary RLC entity cannot be deactivated.

9. The terminal according to claim 1, wherein, The at least one processor is further configured to: The secondary RLC entity indicated by the PDCP entity to be deactivated discards all replicated PDCP packets.

10. The terminal according to claim 1, wherein, The at least one processor is further configured to: receive logical channel configuration information from a base station, the logical channel configuration information including information associated with at least one cell used by a logical channel, and determine that the information associated with at least one cell used by the logical channel is not applied when none or only one of a plurality of RLC entities including a primary RLC entity and the plurality of secondary RLC entities remains active.

11. The terminal according to claim 1, wherein, The at least one processor is further configured to: receive logical channel configuration information from a base station, the logical channel configuration information including information associated with cell restrictions mapped to a logical channel; wherein, when none or only one of a plurality of RLC entities including a primary RLC entity and the plurality of secondary RLC entities remains active in a cell group, the cell restrictions are not applied regardless of the information associated with the cell restrictions mapped to the logical channel.

12. A method for controlling packet replication in a wireless communication system, executed by a terminal, the method comprising: receive a duplicate activation / deactivation media access control (MAC) control element (CE) associated with a plurality of secondary radio link control (RLC) entities for a data radio bearer (DRB) from a base station, and in a case where the duplicate activation / deactivation MAC CE associated with the plurality of secondary RLC entities for the DRB indicates duplicate activation of at least one secondary RLC entity among the plurality of secondary RLC entities for the DRB, duplicate a first packet data convergence protocol (PDCP) packet for the at least one secondary RLC entity, deliver the first PDCP packet to the primary RLC entity, and deliver the duplicated first PDCP packet to at least one secondary RLC entity, wherein the duplicate activation / deactivation MAC CE associated with the plurality of secondary RLC entities for the DRB includes an identifier of the DRB and a plurality of RLC fields regarding the DRB, and wherein an RLC field among the plurality of RLC fields regarding the DRB corresponds to a secondary RLC entity among the plurality of secondary RLC entities and indicates an activation or deactivation state of PDCP duplication for the secondary RLC entity.

13. The method according to claim 12, further comprising: send to the base station capability information indicating whether duplicate transmission is supported by using more than two RLC entities.

14. The method according to claim 12, further comprising: receive, via radio resource control (RRC) signaling from a base station, duplicate configuration information including an indication of a PDCP duplication state of a plurality of secondary RLC entities; identify, based on the duplicate configuration information, at least one RLC entity for packet duplicate transmission from among the plurality of secondary RLC entities; duplicate a second PDCP packet for the identified at least one RLC entity; and deliver the duplicated second PDCP packet to the identified at least one RLC entity.

15. The method according to claim 14, wherein, The duplicate configuration information includes a plurality of duplicate fields corresponding to the plurality of secondary RLC entities, wherein, in a case where a first duplicate field among the plurality of duplicate fields is set to "true", PDCP duplication for the secondary RLC entity corresponding to the first duplicate field is activated, and in a case where the first duplicate field is set to "false", PDCP duplication for the secondary RLC entity corresponding to the first duplicate field is deactivated.

16. The method according to claim 12, wherein, The multiple RLC fields regarding the DRB are identified in ascending order of the logical channel ID in the order of the master cell group (MCG) and the secondary cell group (SCG).

17. The method according to claim 12, the method further comprising: When the RLC field is set to 1, activate the PDCP duplication of the secondary RLC entity corresponding to the RLC field, and When the RLC field is set to 0, deactivate the PDCP duplication of the secondary RLC entity corresponding to the RLC field.

18. The method according to claim 12, wherein, The primary RLC entity cannot be deactivated.

19. The method according to claim 12, further comprising: Receive logical channel configuration information from the base station, including information associated with at least one cell used by the logical channel; and When none or only one of the multiple RLC entities including the primary RLC entity and the multiple secondary RLC entities remains active, determine that the information associated with at least one cell used by the logical channel is not applied.

20. The method according to claim 12, further comprising: Receive logical channel configuration information from the base station, including information associated with the cell restriction mapped to the logical channel, wherein when none or only one of the multiple RLC entities including the primary RLC entity and the multiple secondary RLC entities remains active in the cell group, the cell restriction is not applied regardless of the information associated with the cell restriction mapped to the logical channel.

Images