KR20180081446A - Methods for controlling a data redundant transmission and Apparatuses thereof - Google Patents

Abstract

The present invention relates to a specific method for redundant transmission of duel- or multi-connectivity-based data and a device thereof. According to an embodiment, the method for redundant transmission of data by a terminal having dual connection comprises: a step of receiving a radio resource control (RRC) message including configuration information for configuring redundant transmission in a packet data convergence protocol (PDCP) entity from a base station; a step of configuring redundant transmission in the PDCP entity for one or more radio bearers; a step of receiving indication information indicating whether to activate a redundant transmission operation of the configured PDCP entity from the base station; and a step of copying a PDCP protocol data unit (PDU) from the PDCP entity, transferring the PDCP PDU to a different radio link control (RLC) entity, and transmitting the same data to a plurality of base stations in a redundant manner if the indication information indicates activation. According to the present invention, it is possible to rapidly transceive a large amount of data.

Description

[0001] The present invention relates to a method and a device for controlling data redundant transmission,

The present disclosure relates to a specific method and apparatus for redundantly transmitting dual or multi-connectivity-based data.

As communications systems evolved, consumers, such as businesses and individuals, used a wide variety of wireless terminals.

In a mobile communication system such as LTE (Long Term Evolution), LTE-Advanced, and 5G of the current 3GPP series, a high-speed and large-capacity communication system capable of transmitting and receiving various data such as video data and wireless data is required beyond a voice- have. In addition, technologies for next generation wireless access networks for accommodating data transmission and reception of more terminals after LTE-Advanced and providing higher QoS are being developed. For example, a development work for a tentative 5G network centering on 3GPP is under way.

However, even if the next generation wireless access network technology is developed, a terminal and a base station using existing network technology will exist together, and a terminal will provide services using an existing network and a next generation network. In particular, in the case of a dual connectivity technology in which a terminal maintains connection with two or more base stations and provides a service, base stations using different network technologies (radio access technology, RAT) are used according to the development of the next generation radio access network technology It is necessary to provide services.

However, at present, a specific method and terminal operation for providing dual connectivity by using a base station using existing network technology and a base station using a next generation network are not defined.

In addition, there is a need to transmit data redundantly through a plurality of radio paths for reliable data transmission and reception with a low delay, such as a URLLC service.

In view of the foregoing, the present disclosure intends to propose a specific procedure and operation for a terminal to perform dual connectivity using a plurality of base stations.

In addition, the present disclosure proposes a specific procedure and operation for redundantly transmitting data when a terminal and a base station form a dual connection.

In order to solve the above-described problems, one embodiment of the present invention provides a method for redundant transmission of data by a terminal having a dual connection, comprising the steps of: configuring redundant transmission in a PDCP (Packet Data Convergence Protocol) Comprising: receiving a Radio Resource Control (RRC) message including information on a PDCP entity, configuring a redundant transmission on a PDCP entity for one or more radio bearers, and instructing whether to activate the redundant transmission operation of the PDCP entity configured by the base station And when the instruction information indicates activation, the PDCP entity copies the PDCP PDU (Protocol Data Unit) and transmits the same to different RLC (Radio Link Control) entities to duplicate the same data to the plurality of base stations The method comprising the steps of:

In addition, one embodiment of the present invention provides a method of receiving data redundantly by a base station having a dual connection with a terminal, the method comprising: configuring a redundant transmission in a PDCP (Packet Data Convergence Protocol) entity of the UE for one or more radio bearers Transmitting an RRC (Radio Resource Control) message including configuration information for the PDCP entity to the UE, transmitting indication information indicating whether to activate the redundant transmission operation of the configured PDCP entity, And duplicating the data copied and transmitted from the PDCP entity of the UE through the RLC entity of the base station and the RLC entity of another base station constituting the dual connection to the UE.

In an exemplary embodiment of the present invention, a UE having a dual connection configured to transmit data redundantly includes a Radio Resource Control (RRC) layer including configuration information for configuring redundant transmission in a Packet Data Convergence Protocol (PDCP) ) Message, and includes a receiving unit for receiving indication information indicating whether to activate the redundant transmission operation of the PDCP entity configured by the base station, a controller for configuring redundant transmission in the PDCP entity for one or more radio bearers, And a transmitter for copying a PDCP PDU (Protocol Data Unit) from a PDCP entity and transferring the PDCP PDU to different RLC (Radio Link Control) entities to duplicate the same data to a plurality of base stations.

In an exemplary embodiment of the present invention, a base station for establishing a dual connection with a mobile station and redundantly receiving data, the base station comprising: a base station for configuring redundant transmission in a PDCP (Packet Data Convergence Protocol) A transmission unit for transmitting an RRC (Radio Resource Control) message including configuration information to the UE, for transmitting indication information indicating whether to activate the redundant transmission operation of the configured PDCP entity, and, if the indication information indicates activation, And a receiver for receiving the data copied and transmitted from the PDCP entity through the RLC entity of the base station and the RLC entity of another base station constituting the dual connection to the terminal.

The present disclosure provides an effect that a terminal transmits and receives a large amount of data quickly by configuring dual connectivity using radio resources of a plurality of base stations.

In addition, the present disclosure provides redundancy transmission of data while minimizing the waste of radio resources in a double connection environment, thereby providing an effect of supporting low-delay and high-reliability data transmission / reception service.

1 is a diagram for explaining a secondary base station addition procedure according to the related art.
2 is a diagram for explaining a terminal operation according to an embodiment.
3 is a diagram for explaining a base station operation according to an embodiment.
4 is a diagram illustrating a dual connectivity SRB configuration according to one embodiment.
5 is a diagram illustrating a dual connectivity SRB configuration according to another embodiment.
6 is a diagram illustrating a dual connectivity SRB configuration according to another embodiment.
7 is a diagram for explaining a terminal configuration according to an embodiment.
8 is a diagram for explaining a base station configuration according to an embodiment.

Hereinafter, some embodiments of the present invention will be described in detail with reference to exemplary drawings. It should be noted that, in adding reference numerals to the constituent elements of the drawings, the same constituent elements are denoted by the same reference symbols as possible even if they are shown in different drawings. In the following description of the present invention, a detailed description of known functions and configurations incorporated herein will be omitted when it may make the subject matter of the present invention rather unclear.

As used herein, a wireless communication system refers to a system for providing various communication services such as voice, packet data, and the like. A wireless communication system includes a user equipment (UE) and a base station (BS).

The user terminal is a comprehensive concept that means a terminal in a wireless communication, and it is a comprehensive concept which means a mobile station (MS) in GSM, a mobile station (MS) in UT (User Terminal), a Subscriber Station (SS), a wireless device, and the like.

A base station or a cell generally refers to a station that communicates with a user terminal and includes a Node-B, an evolved Node-B, a gNode-B, a Low Power Node A sector, a site, various types of antennas, a base transceiver system (BTS), an access point, a point (for example, a transmission point, a reception point, a transmission / reception point) (RRH), a radio unit (RU), and a small cell, as well as a relay cell, a relay node, a megacell, a macrocell, a microcell, a picocell, a femtocell, an RRH,

Since the various cells listed above exist in the base station controlling each cell, the base station can be interpreted into two meanings. Macro cell, micro cell, picocell, femtocell, small cell, or 2) the wireless region itself in connection with the wireless region. 1), all of the devices that interact to configure the wireless area to be cooperatively controlled by the same entity are all pointed to the base station. A point, a transmission / reception point, a transmission point, a reception point, and the like are examples of the base station according to the configuration method of the radio area. 2 may direct the base station to the wireless region itself to receive or transmit signals at the point of view of the user terminal or in the vicinity of the neighboring base station.

In this specification, a cell refers to a component carrier having a coverage of a signal transmitted from a transmission point or a transmission point or a transmission point or a transmission / reception point of a signal transmitted from a transmission / reception point, and a transmission / reception point itself .

Herein, the user terminal and the base station are used in a broad sense as two (uplink or downlink) transmitting and receiving subjects used to implement the technology or technical idea described in the present invention, and are not limited by a specific term or word Do not.

Here, an uplink (UL, or uplink) means a method of transmitting / receiving data to / from a base station by a user terminal, and a downlink (DL or downlink) .

The time division duplex (TDD) scheme, which is transmitted using different time periods, can be used for the uplink and downlink transmission, and a frequency division duplex (FDD) scheme in which different frequencies are used, a TDD scheme and an FDD scheme A hybrid method can be used.

In the wireless communication system, the uplink and the downlink are configured with reference to one carrier or carrier pair to form a standard.

The uplink and the downlink transmit control information through a control channel such as a physical downlink control channel (PDCCH), a physical uplink control channel (PUCCH), and the like. The physical downlink shared channel (PDSCH), the physical uplink shared channel (PUSCH) It is composed of the same data channel and transmits data.

A downlink may refer to a communication or communication path from a multipoint transmission / reception point to a terminal, and an uplink may refer to a communication or communication path from a terminal to a multiple transmission / reception point. At this time, in the downlink, the transmitter may be a part of the multiple transmission / reception points, and the receiver may be a part of the terminal. Also, in the uplink, the transmitter may be a part of the terminal, and the receiver may be a part of multiple transmission / reception points.

Hereinafter, a situation in which a signal is transmitted / received through a channel such as PUCCH, PUSCH, PDCCH, and PDSCH is expressed as 'PUCCH, PUSCH, PDCCH and PDSCH are transmitted and received'.

Meanwhile, the High Layer Signaling described below includes RRC signaling for transmitting RRC information including RRC parameters.

The base station performs downlink transmission to the UEs. The base station includes downlink control information, such as scheduling, required for reception of a downlink data channel, which is a primary physical channel for unicast transmission, and physical downlink control information for transmitting scheduling grant information for transmission in an uplink data channel. A control channel can be transmitted. Hereinafter, the transmission / reception of a signal through each channel will be described in a form in which the corresponding channel is transmitted / received.

There are no restrictions on multiple access schemes applied in wireless communication systems. (TDMA), Frequency Division Multiple Access (FDMA), Code Division Multiple Access (CDMA), Orthogonal Frequency Division Multiple Access (OFDMA), Non-Orthogonal Multiple Access (NOMA) Various multiple access schemes such as OFDM-CDMA can be used. Here, the NOMA includes Sparse Code Multiple Access (SCMA) and Low Density Spreading (LDS).

One embodiment of the present invention relates to asynchronous wireless communications that evolve into LTE / LTE-Advanced, IMT-2020 over GSM, WCDMA, HSPA, and synchronous wireless communications such as CDMA, CDMA- Can be applied.

In this specification, a MTC (Machine Type Communication) terminal may mean a terminal supporting low cost (or low complexity) or a terminal supporting coverage enhancement. Alternatively, the MTC terminal may refer to a terminal defined in a specific category for supporting low cost (or low complexity) and / or coverage enhancement.

In other words, the MTC terminal in this specification may mean a newly defined 3GPP Release-13 low cost (or low complexity) UE category / type for performing LTE-based MTC-related operations. In this specification, the MTC terminal supports the enhanced coverage over the existing LTE coverage, or the UE category / type defined in the existing 3GPP Release-12 or lower that supports the low power consumption, or the newly defined Release-13 low cost low complexity UE category / type. Or a further Enhanced MTC terminal defined in Release-14.

In this specification, NarrowBand Internet of Things (NB-IoT) terminal means a terminal supporting wireless access for cellular IoT. The objectives of NB-IoT technology include improved indoor coverage, support for large-scale low-rate terminals, low latency sensitivity, ultra-low cost, low power consumption, and optimized network architecture.

Enhanced Mobile Broadband (eMBB), massive Machine Type Communication (mMTC), and Ultra Reliable and Low Latency Communication (URLLC) have been proposed as typical usage scenarios in NR (New Radio), which is under discussion in 3GPP.

In this specification, a frequency, a frame, a subframe, a resource, a resource block, a region, a band, a subband, a control channel, a data channel, a synchronization signal, various reference signals, various signals, May be interpreted as past or presently used meanings or various meanings used in the future.

The term " dual connection " as used herein refers to a technique by which a terminal can transmit / receive data by configuring a wireless connection with a plurality of base stations, and describes dual connectivity or multi-connectivity. However, a dual connection or dual connectivity is a term for convenience of description, and the term is not limited.

LTE  LTE Dual Connectivity operation

Conventional LTE technology supports a dual connectivity technology in which a terminal simultaneously uses two base station radio resources. For multiple RX / TX terminals in the RRC Connected state, the dual connectivity operation is configured to utilize the radio resources provided by two different schedulers located connected to two base stations connected via a non-ideal backhaul.

In dual connectivity, a terminal can provide services through two base stations. For example, the terminal can perform communication using the master base station MeNB and the secondary base station SeNB. The master base station may provide a RRC connection to the terminal and may be referred to as a base station for handover, and the secondary base station may refer to a base station that provides additional radio resources to the terminal.

To provide SeNB radio resources to the terminal, an SeNB addition procedure is used to set the terminal context to the SeNB.

1 is a diagram for explaining a secondary base station addition procedure according to the related art.

Each step will be described with reference to Fig.

1. In step S100, the MeNB 110 requests the SeNB 120 to allocate a radio resource for indicating a characteristic for a particular E-RAB (The MeNB 110 decides to request the SeNB 120 to allocate radio resources for a specific E-RAB, indicating E-RAB characteristics (E-RAB parameters, corresponding to the UP option). In addition, the MeNB 110 uses the MCG configuration (including the security algorithm for the SCG bearer) and the entire UE function for UE function adjustment as the basis for reconstruction by the SeNB 120 in the SCG-ConfigInfo, but does not include the SCG configuration (In addition, MeNB (110) indicates within SCG-ConfigInfo, the MCG configuration (including security algorithm for SCG bearer) and the entire UE capabilities for UE configuration are used on the basis of the reconfiguration by the SeNB 120, , but does not include SCG configuration). The MeNB 110 may provide the latest measurement results for the additional requested SCG cell (The MeNB 110 may provide the latest measurement results for the requested SCG cell). SeNB 120 may reject the request (The SeNB 120 may reject the request).

2. If the RRM entity in the SeNB 120 can approve the resource request through step S101, the RRC entity allocates each radio resource and allocates each transmission network resource according to the bearer option (if the RRM entity in the SeNB (120) is able to request the resource request, it allocates the respective radio resources and, depending on the bearer option, the respective transport network resources). The SeNB 120 may trigger random access and perform synchronization of the SeNB 120 radio resource configuration. (The SeNB 120 triggers Random Access so that synchronization of the SeNB 120 radio resource configuration can be performed). The SeNB 120 provides new radio resources of the SCG of the SCG-Config to the MeNB 110 (The SeNB 120 provides the new radio resource of the SCG in the SCG-Config to the MeNB 110). SCL bearer, together with S1 DL TNL address information for each E-RAB and security algorithm for the SCG bearer (For SCG bearers, together with S1 DL TNL address information for the respective E- RAB and security algorithm, for split bearers X2 DL TNL address information).

3. If the MeNB 110 approves the new configuration through step S102, the MeNB 110 transmits an RRCConnectionReconfiguration message including the new radio resource configuration of the SCG to the UE according to the SCG-Config (If the MeNB Ends the new configuration, the MeNB (110) sends the RRCConnectionReconfiguration message to the UE including the new radio resource configuration of the SCG-Config) .

4. In step S103, the UE 100 applies a new configuration and responds with an RRCConnectionReconfigurationComplete message. If the UE 100 fails to apply (part of) the configuration included in the RRCConnectionReconfiguration message, the UE 100 performs a reconfiguration failure procedure (In case the UE does not comply with the configuration included in the RRCConnectionReconfiguration message, it performs the reconfiguration failure procedure).

5. In step S104, the MeNB 110 informs the SeNB 120 that the UE 100 has successfully completed the reconfiguration procedure (the MeNB 110 informs the SeNB 120 that the UE has completed the reconfiguration procedure successfully).

6. In step S105, the UE 100 performs synchronization with the PSCell of the SeNB 120 (the UE performs synchronization with the PSCell of the SeNB 120). The order in which the UE 100 transmits an RRCConnectionReconfigurationComplete message and performs a random access procedure toward the SCG is not defined ( RRCConnectionReconfigurationComplete message and performs Random Access Procedure to the SCG is not defined). A successful RA procedure for the SCG is not required to successfully complete the RRC connection reconfiguration procedure (the successful RA procedure is not required for a successful completion of the RRC Connection Reconfiguration procedure).

7./8. Through steps S106 and S107, in the case of the SCG bearer, depending on the bearer characteristics of each E-RAB, the MeNB 110 can take steps to minimize service interruption due to dual connection (data transfer, SN state transfer) activation (In case SCG bearers, and depending on the bearer characteristics of the respective E-RABs, the MeNB (110) may take actions to minimize service interruption due to activation of dual connectivity (SN forwarding)).

9.-12. In the case of the SCG bearer through steps S108 to S111, the UP path is updated to the EPC (For SCG bearers, the update of the EPC is performed).

In step S102, when the MeNB 110 sends an RRC connection reconfiguration message including a new radio resource configuration of the secondary cell group, the UE 100 applies a new configuration as in step S103. If the UE 100 can not comply with the (some) configuration included in the RRC connection reconfiguration message, the UE 100 performs the reconfiguration failure procedure.

In the conventional LTE dual connectivity technology provided based on coordination between two LTE base stations, the MeNB 110 can understand the radio resource control (RRC) message of the SeNB 120. Considering the coordination between the UE capabilities and the SeNB 120, the MeNB 110 generates the final RRC message and instructs the UE 100 to efficiently utilize the radio resources of the two base stations . The RRC message could only be provided through the radio interface of the UE 100 and the MeNB 110. [

NR (New Radio)

3GPP is conducting research on next generation / 5G wireless access technology (hereinafter referred to as NR for convenience of explanation). As a requirement for architecture and migration for next-generation wireless access technologies, the RAN architecture needs to support tight interworking between NR and LTE wireless access technologies. Also, dual connectivity techniques can be used between NR base stations in NR radio access technology. Dual connectivity in an NR environment can be defined as multi-connectivity. For example, the multi-connectivity may be defined as the mode of operation of a terminal for utilizing radio resources configured by LTE base stations and / or NR base stations (Multi-Connectivity: mode is configured to utilize radio resources amongst E-UTRA and / or NR provided by multiple distinct schedulers connected via non-ideal backhaul).

The NR radio access technology can also be established at high frequencies (e.g., high frequencies above 6 GHz). In this case, fast SINR drops may occur depending on the link blocking factor in the high frequency band and high transmission loss. This may lead to unnecessary delays or reduce reliability if the NR base station wishes to send control plane RRC messages or user plane data via the NR and the inter-terminal interface. In particular, such a problem makes it difficult to provide services such as Ultra-Reliable Low Latency Communications (URLLC). As an example for solving such a problem, it is possible to transmit the control plane RRC message over one or more radio paths by using RRC diversity technology. As another example for solving such a problem, the user plane data may be redundantly transmitted over one or more wireless paths based on the multi-connectivity.

However, there is a problem that redundant transmission consumes additional radio resources. In other words, redundant transmission over two or more radio paths may be considered as a method for reliably providing a service such as URLLC in a radio access network with a low delay. However, in the case of transmitting the same data, There is a problem of consuming additional radio resources.

It is an object of the present disclosure to solve such a problem to provide a redundant transmission processing method and apparatus capable of efficiently processing a service such as URLLC.

The embodiments described below can be applied not only to the next generation mobile communication (5G mobile communication / NR) terminal but also to any radio access network terminal.

For convenience of explanation, the base station may represent an eNodeB or an LTE base station of an LTE / E-UTRAN or an NR Node, a CU, a DU, or a Node B in a 5G wireless network in which a CU (Central Unit) The gNodeB, the NR base station (CU, DU, or CU and DU) implemented as a single logical entity and the CU and the DU are implemented as a single logical entity, hereinafter referred to as an NR base station for convenience of description, All entities may be included in the scope of this disclosure). Therefore, in the following description, a base station, an NR base station, an LTE base station, and the like are denoted as necessary, and an NR base station and an LTE base station are classified according to a radio access technology. However, these terms are for the convenience of explanation and division, and there is no limitation to the terms.

In order to describe a method for setting up dual connectivity between an LTE base station and an NR base station using different radio access technologies, an LTE base station is described as a master base station and a NR base station is described as a secondary base station Will be described. However, the present disclosure can be applied to dual connectivity between LTE base stations, and the same can be applied to a case where the secondary base station is an LTE base station. Likewise, the present disclosure can be applied even when the NR base station is the master base station and the LTE base station is the secondary base station, and can be applied to dual connectivity between LTE base stations.

Therefore, in the following description, LTE base stations and NR base stations are separately described. When it is necessary to describe operations according to dual connectivity, the LTE base station is described as a master base station (MeNB) and the NR base station is referred to as a secondary base station . The name of each base station is for convenience of understanding, the LTE base station may denote an eNB, and the NR base station may denote a gNB. In other words, the present disclosure describes base stations by distinguishing between base stations using different radio access technologies, and the terms are not limited.

The following scenarios can be considered for core network connection in dual connectivity for NR.

When the NR is integrated in the LTE and connected via EPC, the control plane is connected between the LTE base station and the EPC entity (MME), and the user plane can be separated from the core network or the wireless network.

When a plurality of NR base stations are aggregated and connected through an NG-Core (5G core network), the control plane is connected between the NR base station and the NG-Core control plane entity, and the user plane is connected to the core network or the wireless network Can be separated.

- When LTE is integrated in NR and connected via NG-Core (5G core network), the control plane is connected between the NR base station and the NG-Core control plane entity, and the user plane is connected to the core network or the wireless network Can be separated.

- When NR is integrated in LTE and connected through NG-Core (5G core network), the control plane is connected between the LTE base station and the NG-Core control plane entity, and the user plane is connected to the core network or the wireless network Can be separated.

The dual or multi-connectivity for NR (hereinafter referred to as dual connectivity for convenience of description, but also providing two or more connectivity is also included in the scope of the present disclosure), the following three cases can be considered.

- LTE (Master Node) - NR (Secondary Node)

- NR (Master Node) - NR (Secondary Node)

- NR (Master Node) - LTE (Secondary Node)

For dual / multi-connectivity for NR, the following cases can be considered.

- intra frequency dual / multi-connectivity

- inter frequency dual / multi-connectivity

 The NR base station may add (modify, release or manage) NR cells (cell groups or transmission points or transmission point groups or transmission / reception points or transmission / reception point groups or TRPs or antennas or antenna groups or beams, Measurement control, measurement reporting, NR resource allocation, NR radio bearer addition / correction / release, NR radio resource configuration, and NR mobility control. The NR base station may indicate one or more of the control functions described above for the terminal via an RRC configuration or reconfiguration message.

For example, the LTE RRC entity of the LTE base station and the NR RRC entity of the NR base station can independently designate the corresponding base station radio resource control configuration. In another example, the LTE RRC entity of the LTE base station can instruct the NRT RRC entity of the NR base station to independently configure the corresponding base station radio resource control configuration through the inter-terminal interface between the LTE and the UE. In another example, the LTE RRC entity of the LTE base station and the NR RRC entity of the NR base station can independently designate a corresponding base station radio resource control configuration within a range not exceeding the terminal capability. In another example, the LTE RRC entity of the LTE base station and the NR RRC entity of the NR base station may instruct the corresponding base station radio resource control configuration through adjustment. In another example, an LTE RRC entity of an LTE base station may direct LTE base station radio resource control configuration via an LTE radio link and an NR radio link. In another example, the NR RRC entity of the NR base station may direct the LTE base station radio resource control configuration via the NR radio link and the LTE radio link.

Specific methods for transmitting the above-described radio resource control signaling will be described later.

The terminal and the base station can transmit data redundantly using dual connectivity configured in the terminal to transmit low-delay high-reliability data. That is, the UE can duplicate uplink data through two base stations, and the BS can also duplicate downlink data using another base station that forms a dual connection to the UE. However, when all the data are redundantly transmitted using a plurality of radio paths, limited radio resources are wasted. Accordingly, in the present disclosure, an embodiment of redundant data transmission in order to provide a low-delay high-reliability service while minimizing the waste of limited radio resources is proposed.

For example, on a dual connectivity-based handover, the master base station (or secondary base station) may direct an RRC signaling message to be transmitted over a plurality of paths through a signaling radio bearer configured between two base stations and a terminal.

As another example, the master base station (or the secondary base station) can instruct the terminal configured with the dual connectivity to transmit the user plane data through the plurality of paths through the data radio bearers configured between the two base stations and the terminals.

As another example, the master base station (or the secondary base station) can instruct the terminal configured with the dual connectivity to transmit the user plane data through one path through the data radio bearer phase data configured between the two base stations and the terminals. At this time, it is possible to indicate a condition for switching a specific single path between the redundant transmission and the single path transmission or within multiple paths. For example, the condition may be an uplink data separation threshold. If the data redundancy transmission is not configured and active, and if the data transfer is configured but not activated, if the available PDCP data volumes associated with the two RLC entities and the RLC data volume are less than the corresponding conditions, the PDCP data To the configured single path RLC entity.

Additional radio resources are consumed by redundantly transmitting RRC signaling messages or user plane data on a plurality of radio interfaces. However, it is possible to improve the reliability of the transmission of the control plane message or the transmission of the user plane data. Also, if the secondary base station can transmit the RRC message directly to the mobile station via the air interface, there may be an advantage that data can be transmitted quickly without delaying the backhaul interval between the base stations.

As described above, the multi-path redundant transmission scheme improves the reliability but consumes radio resources due to complexity and redundant transmission. Hereinafter, the description will be made on the basis of the redundant transmission of the RRC message. This is for convenience of explanation, and user plane data redundant transmission can be equally provided. Therefore, user plane data redundant transmission is also included in the scope of the present embodiment. For example, it may be handled by the PDCP entity of the individual radio bearer that processes it per control plane data or user plane data.

In the following description, the case where the UE transmits uplink data will be mainly described, but the same procedure can also be applied when the base station transmits downlink data. In the present specification, the dual connectivity is used in the case where the dual connectivity is configured by a plurality of base stations using NR-NR, NR-LTE or LTE-NR radio access technology, and also includes the meaning of multi-connectivity Should be interpreted as doing.

Hereinafter, operations of a terminal and a base station for data duplication according to an embodiment will be described with reference to FIG. 2 and FIG. 3, and more specific embodiments will be described later.

2 is a diagram for explaining a terminal operation according to an embodiment.

Referring to FIG. 2, a UE according to an exemplary embodiment of the present invention includes an RRC (Radio Resource Control) message including configuration information for configuring redundant transmission in a Packet Data Convergence Protocol (PDCP) entity from a base station (S210). A terminal can form a dual connection (dual connectivity) with a plurality of base stations. The plurality of base stations can be set to use different radio access technologies. For example, the master base station may be the gNB using the NR radio access technology described above, and the secondary base station may be the eNB using the LTE radio access technology. Or the master base station may be an eNB using LTE radio access technology and the secondary base station may be a gNB using NR radio access technology. Or both the master base station and the secondary base station may be gNBs using NR radio access technology. The dual connection can be configured in the terminal by the base station, and the terminal can transmit and receive data using the radio resources configured with each of the plurality of base stations.

A UE having the above-described dual connection can receive a Radio Resource Control (RRC) message including configuration information for configuring redundant transmission in a Packet Data Convergence Protocol (PDCP) entity from a base station. The configuration information may include specific information for supporting the redundant transmission function in the PDCP entity. For example, the configuration information includes a processing operation when duplicated data is received from the PDCP entity, a processing operation when the redundant transmission function is activated or not, an operation indicating two RLC entity configurations associated with the PDCP entity, The PDCP entity may include information for configuring the terminal so that at least one operation of transmitting data having the same PDCP SN through two paths can be performed.

The UE may perform a step of configuring redundant transmission in the PDCP entity for one or more radio bearers (S220). For example, the UE may configure the PDCP entity to transmit data having the same PDCP SN on a plurality of paths based on the configuration information. The UE configures the redundant transmission in the PDCP entity, but can configure it to be in a disabled state. Alternatively, the terminal may configure the redundant transmission function in the PDCP entity to be in the active state. The UE can construct two RLC entities associated with the PDCP entity configured for PDCP redundancy transmission.

Thereafter, the UE may perform a step of receiving indication information indicating whether to activate the redundant transmission operation of the PDCP entity configured by the BS (S230). For example, the indication information may be received via a Medium Access Control Element (MAC). The indication information may include information indicating whether to change the redundant transmission function of the PDCP entity for the radio bearer to perform PDCP redundancy transmission to the active state or to the inactive state. If the indication information indicates activation for a specific radio bearer to perform PDCP redundancy transmission, the MAC entity of the UE can instruct the upper layer to activate the redundancy transmission operation of the PDCP entity for the specific radio bearer. That is, if the indication information received through the MAC CE indicates the activation of the redundant transmission function, the MAC entity of the UE can transmit the indication to the upper layer (for example, the RRC layer or the PDCP layer).

If the indication indicates activation, the terminal copies the PDCP PDU (Protocol Data Unit) from the PDCP entity and transfers the PDCP PDU to a different Radio Link Control (RLC) entity to duplicate the same data to the plurality of base stations (S240). For example, when the redundant transmission function of the PDCP entity is configured (or changed) by the above-described instruction information for a specific radio bearer to perform the PDCP redundancy transmission configured in the UE, the PDCP entity And transmits the same data to the base station through a plurality of radio paths by transferring the data to be transmitted to the base station to a plurality of RLC entities connected to the PDCP entity for a specific radio bearer to perform the PDCP redundancy transmission.

Meanwhile, a plurality of RLC entities may be configured in the UE for each BS constituting the dual connection, and may be associated with one PDCP entity. A plurality of RLC entities may be associated with one corresponding PDCP entity through a radio bearer identifier or a logical channel identifier. Accordingly, when a PDCP entity transmits the same data to a plurality of RLC entities associated with each other, each base station can receive the same data. The master base station receives data through a radio resource between the master base station and the terminal, By receiving the same data, the data transmitted by the terminal can be received redundantly. In this case, the PDCP entity of the base station can remove any of the redundantly received data packets and transmit the data to an upper layer. For example, it is possible to first transmit a received data packet to an upper layer and then to remove a data packet having the same SN received thereafter.

If the PDCP entity instructs the radio bearer to indicate inactivation of the PDCP redundant transmission activation and the PDCP entity re-transmission operation for the radio bearer is configured in the UE, the PDCP entity may select one of the plurality of RLC entities PDCP PDUs. That is, when a redundant transmission function of a PDCP entity is configured for a specific radio bearer to perform a PDCP redundancy transmission to a UE but the corresponding PDCP entity is inactivated, Data can be transmitted only to the RLC entity and data can be transmitted through a single path. It may be an RLC entity configured by default for the corresponding radio bearer. It can be used in various names such as an RLC entity, a primary RLC entity, a default RLC entity, and a first-constructed RLC entity configured for convenience of explanation, and its name is not limited.

In addition, the redundant transmission function described above may be configured only for the data radio bearer (DRB). For example, the redundant transmission function on the PDCP entity is not configured for the signaling radio bearer, but can only be configured for the data radio bearer.

In addition, the indication information may indicate whether to enable the PDCP entity to perform a redundant transmission operation for each of the one or more data radio bearers. For example, the indication information may include information on whether to enable the redundant transmission function in the PDCP entity for each data radio bearer configured in the UE. In this case, the PDCP redundancy transmission function is activated for the specific data radio bearer, but the PDCP redundancy transmission function can be indicated to be inactivated for other data radio bearers. The indication information provided through the MAC CE to indicate whether the corresponding PDCP entity for each of the one or more data radio bearers is to be activated or deactivated is configured to indicate an activation / deactivation state for each radio bearer corresponding to each radio bearer identifier And may include bitmap information.

The above-mentioned base station may be a master base station or a secondary base station.

Accordingly, redundancy transmission is determined for each data radio bearer, thereby minimizing radio resource waste and data processing processing time loss due to redundant transmission. In addition, a redundant transmission function is configured in the UE, and dynamic control effect on radio resources is provided by dynamically controlling activation or deactivation through the MAC CE.

3 is a diagram for explaining a base station operation according to an embodiment.

Referring to FIG. 3, a base station according to an exemplary embodiment includes a Radio Resource Control (RRC) system including configuration information for configuring redundant transmission in a PDCP (Packet Data Convergence Protocol) And transmitting the message to the terminal (S310). The base station can construct a dual connection to the terminal together with other base stations. As described above, the base stations constituting the dual connection can be set to use different radio access technologies. For example, the master base station may be the gNB using the NR radio access technology described above, and the secondary base station may be the eNB using the LTE radio access technology. Or the master base station may be an eNB using LTE radio access technology and the secondary base station may be a gNB using NR radio access technology. Or both the master base station and the secondary base station may be gNBs using NR radio access technology. In addition, the base station in Fig. 3 may be a master base station or a secondary base station.

Meanwhile, the BS may transmit an RRC message including configuration information for configuring redundant transmission in the PDCP entity of the UE to one or more radio bearers to the UE. For example, the configuration information may include specific information for supporting the redundant transmission function in the PDCP entity. For example, the configuration information may include a processing operation when duplicated data is received in the PDCP entity of the terminal, a processing operation in the case where the redundant transmission function is activated or not, an operation of instructing the configuration of two RLC entities associated with the PDCP entity And an operation of transmitting data having the same PDCP SN through the two paths of the PDCP entity of the terminal so that at least one operation can be performed.

The terminal may configure redundant transmissions on the PDCP entity for one or more radio bearers based on the configuration information. For example, the UE may configure the PDCP entity to transmit data having the same PDCP SN on a plurality of paths based on the configuration information. The UE can construct two RLC entities associated with the PDCP entity configured for PDCP redundancy transmission.

Thereafter, the BS may perform a step of transmitting indication information indicating whether to activate the redundant transmission operation of the configured PDCP entity (S320). For example, the indication information may be transmitted via a Medium Access Control Element (MAC). The indication information may include information indicating whether to change the redundant transmission function of the PDCP entity for the radio bearer to perform PDCP redundancy transmission to the active state or to the inactive state.

The BS transmits the data copied and transmitted from the PDCP entity for the corresponding radio bearer of the UE to the RLC entity of the base station and the duplicated data for the UE, The RLC entity of the other base station constituting the connection may perform the step of receiving at step S330. For example, if the indication information indicates activation, the MAC entity of the UE can instruct the upper layer to activate the redundancy transmission operation of the PDCP entity. That is, if the indication information received through the MAC CE indicates the activation of the redundant transmission function, the MAC entity of the UE can transmit the indication to the upper layer (for example, the RRC layer or the PDCP layer).

When the indication information indicates activation, the base station can duplicate data copied from the PDCP entity of the UE through the RLC entity of the base station and the RLC entity of another base station constituting the dual connection to the terminal. In this case, the UE copies the PDCP PDU (Protocol Data Unit) from the PDCP entity for the radio bearer to perform the PDCP re-transmission of the UE, and transmits the PDCP PDU to the different RLC (Radio Link Control) So that the base station can repeatedly receive the same data through a plurality of RLC entities. A plurality of RLC entities configured in the UE may be configured in the UE for each BS configuring the dual connection, and may be linked to one PDCP entity. Similarly, a PDCP entity of a base station may be associated with an RLC entity of a corresponding base station, and may be associated with an RLC entity of another base station constituting a dual connection. A plurality of RLC entities may be associated with one corresponding PDCP entity through a radio bearer identifier or a logical channel identifier.

Accordingly, when the PDCP entity of the UE transmits the same data to a plurality of RLC entities associated with it, the PDCP entity of the base station can receive the same data repeatedly. Specifically, a base station receives data through a radio resource between a base station and a terminal, and can receive the same data from another base station through an inter-base station interface. In this case, the PDCP entity of the base station can remove any of the redundantly received data packets and transmit the data to an upper layer.

Alternatively, if the indication information indicates inactivation and the PDCP entity is configured for a redundant transmission operation, the PDCP entity of the base station can receive data only through the RLC entity of the base station. For example, it is possible to first transmit a received data packet to an upper layer and then to remove a data packet having the same SN received thereafter.

On the other hand, the above-mentioned redundant transmission function may be configured only for the data radio bearer (DRB). For example, the redundant transmission function on the PDCP entity is not configured for the signaling radio bearer, but can only be configured for the data radio bearer.

In addition, the indication information may indicate whether to enable the PDCP entity to perform a redundant transmission operation for each of the one or more data radio bearers. For example, the indication information may include information on whether to enable the redundant transmission function in the PDCP entity for each data radio bearer configured in the UE. In this case, the PDCP redundancy transmission function is activated for the specific data radio bearer, but the PDCP redundancy transmission function can be indicated to be inactivated for other data radio bearers. The indication information provided through the MAC CE to indicate whether the corresponding PDCP entity for each of the one or more data radio bearers is to be activated or deactivated is configured to indicate an activation / deactivation state for each radio bearer corresponding to each radio bearer identifier And may include bitmap information.

In this specification, the PDCP entity, the RLC entity, and the MAC entity are described based on the LTE terminology, but the name may be changed in the NR radio access technology. Therefore, the PDCP entity, the RLC entity, and the MAC entity in the present disclosure are understood to mean the entity performing each function in the LTE radio access technology, and the name is not limited. For example, an RLC entity refers to an entity that receives data from a lower layer and transfers the data to an upper layer, performs data segmentation and reassembly, performs reordering, and the like, and its name is not limited .

As described above, according to the present embodiment, it is possible to minimize the loss of radio resources and data processing processing time due to redundant transmission by determining whether or not the data radio bearers are redundantly transmitted. In addition, a redundant transmission function is configured in the UE, and dynamic control effect on radio resources is provided by dynamically controlling activation or deactivation through the MAC CE.

Hereinafter, a more specific embodiment for performing the redundant transmission function in the PDCP entity will be described for each embodiment. These embodiments may be performed by the terminal and the base station described above, and some or all of the steps in FIG. 2 and FIG. 3 may be omitted, changed, substituted and added according to the following embodiments as necessary.

First Embodiment: Method for configuring the activation / deactivation indication information for redundant transmission over multiple paths.

If it is configured to always operate redundant transmission over a plurality of paths, excess radio resources can be wasted. In order to reduce the radio resource consumption due to the redundant transmission, for example, the function (redundant transmission function) is activated / deactivated or on / off (referred to as enable / disable, on / off, activation / deactivation, etc.) can be used.

The downlink RRC data redundancy transmission enables the base station to efficiently transmit RRC data redundantly in an implementation and transmit data.

The base station transmits the RRC message through two paths from the RRC or the PDCP entity.

The terminal receiving the RRC message through the two paths can confirm and process it in the PDCP or RRC. For example, it may first process the received data and discard the duplicated data. For another example, the function of detecting and discarding duplicated data can be performed in the PDCP entity. Specifically, the transmitting side may transmit data having the same PDCP SN through two paths, and the receiving side may detect redundant data based on the PDCP SN. For another example, a PDCP SN with a new PDCP SN is stored. If the PDCP SDU having the same PDCP SN is stored in the UE (or the PDCP entity), the UE discards the PDCP SDU. The base station can indicate the configuration information for the terminal to process this operation.

On the other hand, in order for the UE to efficiently process the uplink RRC data redundancy transmission, it is necessary for the UE to control the RRC or the PDCP entity to transmit the RRC message through two paths by the base station control.

The base station may instruct the terminal to enable / disable the uplink RRC data redundancy transmission. For example, the base station can transmit indication information indicating whether to enable RRC data redundancy transmission to the terminal through the RRC message. The PDCP entity of the UE can be configured to transmit data having the same PDCP SN through two paths.

For example, when instructing the UE by setting the indication information indicating whether the RRC message duplication transmission is enabled, the UE generates the RRC message by transmitting two RRC messages from the PDCP entity, .

In another example, when the BS instructs the UE to set the indication information indicating whether the RRC message duplication transmission is enabled or disabled, the UE generates the RRC message by transmitting one RRC message from the PDCP entity It is possible to transmit it through the path.

In another example, when the base station instructs the terminal to set the information indicating whether to enable the RRC message duplication transmission to be inactivated, when generating the uplink RRC message, the terminal transmits the RRC message to the designated transmission path And the like. The transmission path for this may be pre-configured in the terminal or indicated by the base station. It may be an RLC entity configured by default for the corresponding radio bearer. It can be used in various names such as an RLC entity, a primary RLC entity, a default RLC entity, and a first-constructed RLC entity configured for convenience of explanation, and its name is not limited.

In this manner, the indication information indicating whether the duplicated transmission is activated or not may be indicated to the terminal by higher layer signaling.

Second Embodiment: A method of configuring a timer for enabling / disabling redundant transmission over multiple paths.

If redundant transmission through multiple paths is always operated, excessive radio resources can be wasted.

The downlink RRC data redundancy transmission enables the base station to efficiently transmit RRC data redundantly in an implementation and transmit data.

On the other hand, in order for the UE to efficiently process the uplink RRC data redundancy transmission, it is necessary for the UE to control the RRC or the PDCP entity to transmit the RRC message through two paths by controlling the base station.

If duplicate transmissions are indicated via two paths, it may not be desirable to continue to perform redundant transmissions during the RRC connection. Thus, the base station can indicate a timer for multi-path redundant transmission.

For example, the base station may indicate a redundant transmission activation timer. When the UE receives the RRC message including the redundant transmission activation timer, it starts the corresponding timer. When the uplink RRC message is generated while the timer is operating, the UE may transmit the RRC message through the two transmission paths in the PDCP entity. If the RRC message is generated after the timer expires, the UE can transmit the PDCP entity through one transmission path. The transmission path for this may be pre-configured in the terminal or indicated by the base station. It may be an RLC entity configured by default for the corresponding radio bearer. As described above, the RLC entity, the primary RLC entity, the default RLC entity, and the initial RLC entity configured for convenience of explanation may be used as various names and the names are not limited.

For another example, the base station may indicate a timer for deactivating the redundant transmission when the redundant transmission is activated. After receiving the RRC message including the timer for deactivating the redundant transmission, the UE starts the timer when the redundant transmission is activated according to a specific instruction or condition. When the uplink RRC message is generated while the corresponding timer is operating, the UE may transmit the corresponding RRC message through the two transmission paths from the PDCP entity. If the RRC message is generated after the timer expires, the UE can transmit the PDCP entity through one transmission path.

For example, when the uplink RRC message is generated while the timer for deactivating the redundant transmission is generated, or when the PDCP entity transmits the RRC message through two transmission paths, or when the PDCP entity transmits a redundant transmission It is possible to restart the timer. If the RRC message is generated after the timer expires, the UE can transmit the PDCP entity through one transmission path.

Third Embodiment: A method for indicating activation / deactivation via lower layer information.

The base station can check the radio link quality status of the UE through an RRM measurement report or CQI feedback from the UE. Accordingly, the base station can instruct activation / deactivation of the redundant transmission through the lower layer information.

For example, whether to activate the redundant transmission function in the PDCP entity configured in the UE can be indicated through the MAC CE. That is, if the BS has a redundant transmission function in the PDCP entity, the BS may transmit indication information for instructing activation or deactivation of the corresponding function to the MS, including the MAC CE. The indication information may include information for indicating whether to activate or not for each data radio bearer. When the indication information indicates the activated state, the terminal can transmit data redundantly through a plurality of radio paths. To this end, the PDCP entity may forward the same PDCP PDU to different RLC entities. The indication information provided through the MAC CE to indicate whether the corresponding PDCP entity for each of the one or more data radio bearers is to be activated or deactivated is configured to indicate an activation / deactivation state for each radio bearer corresponding to each radio bearer identifier And may include bitmap information.

For another example, the base station can indicate via the PDCCH indication information indicating whether to activate or not.

In another example, if the UE receives the indication information through the MAC CE or the PDCCH, the UE may transmit the indication information to the RRC or the PDCP layer that processes the redundant transmission.

For another example, the base station may indicate the indication information through the PDCP control data.

Fourth Embodiment: Enabling / Disable  A method for indicating a condition for.

The configuration information indicating the configuration of the RRC message re-transmission to the UE may include condition information for activating / deactivating the RRC data re-transmission. Or the configuration information may include switching information for instructing the terminal to switch the data transmission path between two paths constituted by dual connectivity, and the switching information may include condition information for switching the data transmission path . For convenience of description, the conditions for activating the redundant transmission will be described below. The conditions for instructing to switch the data transmission path between two paths constituted by dual connectivity may be set to be the same or similar. The condition may be included in the above-described condition information.

For example, the reference radio signal quality value for activating the RRC message duplication transmission may be included in the condition information. For example, a terminal may be referred to as a master base station (or a master TRP or a master cell or a PCELL or anchor beam or a best beam, a master base station for convenience of explanation, but any transmission signal on the NR is also included in the scope of the present embodiment) If the quality meets (or exceeds, or is equal to or greater than) the corresponding reference radio quality value, then there is no need to activate the RRC redundant transmission. For example, when the radio quality of the master base station is greater than (or equal to or greater than) the reference value indicated by the base station, the RRC message may be transmitted through one transmission path from the PDCP entity. That is, the corresponding RRC message can be transmitted through the master base station. In another example, the terminal may activate the RRC redundant transmission if the radio quality of the master base station is less than (or equal to or less than) the reference radio quality value. That is, when the radio quality of the master base station is smaller than (or equal to or less than) the threshold value indicated by the base station, the RRC message may be transmitted from the PDCP entity through two transmission paths.

For another example, the condition may be an uplink data separation threshold. If the data redundancy transmission is not configured and activated, and if the data transfer is configured but not activated, if the available PDCP data volumes associated with the two RLC objects and the RLC data volume are less than the corresponding conditions, the PDCP data To the configured single path RLC entity.

In another example, if the radio quality of the secondary base station is greater than (or equal to or greater than) the threshold value indicated by the base station, the RRC message may be transmitted on one transmission path from the PDCP entity. For example, the terminal can transmit data only through the secondary base station.

In another example, the master base station and the secondary base station may be instructed to transmit data via a path that provides better radio quality.

For example, if both the master base station and the secondary base station are smaller than (or equal to or less than) a certain threshold value, the RRC message may be transmitted from the PDCP entity through two transmission paths.

When the condition for activating / deactivating the RRC redundant transmission is satisfied for the above operation, the physical layer can transmit the condition to the upper layer. For example, when transmitting through two transmission paths in the PDCP layer, the physical layer can indicate it as a PDCP entity. Or when the RRC layer transmits through two transmission paths, the physical layer can instruct it to the RRC.

The PDCP entity may activate or deactivate redundant transmissions if indicated by the physical layer that the condition is satisfied.

To this end, the base station may set a threshold of radio quality associated with activation / deactivation, a threshold condition (e.g., a number of quality higher than a threshold, a number of quality lower than a threshold, a number of consecutive out of sync, The uplink data separation data amount threshold value, etc.), a timer for checking a threshold value condition, a period for checking a threshold value condition, an indication condition to an upper layer, and a filtering parameter. For example, an RLM procedure can be used for this purpose. Another example is to use RRM measurements for this. Another example is to use the Beam measurement for this purpose.

The downlink radio quality can be monitored by the UE for a specific cell in the master cell group or for all the cells in the master cell group. This may be for triggering (determining / stopping / canceling / stopping) RRC duplicated transmission or PDCP data (PDCP SDU or PDCP PDU) redundant transmission. Or monitoring may be directed to an upper layer for RRC redundancy transmission or PDCP data redundancy transmission.

Likewise, downlink radio quality can be monitored by the UE for a particular cell in the secondary cell group or for all cells in the secondary cell group. This may be for triggering (determining / stopping / canceling / stopping) RRC duplicated transmission or PDCP data (PDCP SDU or PDCP PDU) redundant transmission. Alternatively, the monitoring may be to indicate to the upper layer a state for RRC redundant transmission or PDCP data redundant transmission.

If the RLM is used, the BS can indicate a threshold value for instructing the upper layer to perform the RLM operation by the physical layer of the UE. The threshold value may be a separate threshold value separate from the threshold value for the conventional general RLM operation.

Through the embodiments described above, it is possible to minimize radio resource waste and data processing processing time loss due to redundant transmission.

Hereinafter, a method of transmitting and processing RRC messages over two wireless links by applying LTE-NR dual connectivity will be described in detail.

For convenience of description, an LTE (Master Node) - NR (Secondary Node) case capable of utilizing well-established LTE coverage will be described below as an example. However, as described above, this is for convenience of description, and the case of a Master Node (NR) - NR (Secondary Node) and an NR (Master Node) - LTE (Secondary Node) is also included in the scope of the present embodiment.

The NR base station can control NR radio resources of the UE. Alternatively, the LTE base station can control the NR radio resources of the UE.

 The NR base station may add (modify, release or manage) NR cells (cell groups or transmission points or transmission point groups or transmission / reception points or transmission / reception point groups or TRPs or antennas or antenna groups or beams, Measurement control, measurement reporting, NR resource allocation, NR radio bearer addition / correction / release, NR radio resource configuration, and NR mobility control. The NR base station may indicate one or more of the control functions described above for the terminal via an RRC configuration or reconfiguration message.

For example, the LTE RRC entity of the LTE base station and the NR RRC entity of the NR base station can independently designate the corresponding base station radio resource control configuration. In another example, the LTE RRC entity of the LTE base station can instruct the NRT RRC entity of the NR base station to independently configure the corresponding base station radio resource control configuration through the inter-terminal interface between the LTE and the UE. In another example, the LTE RRC entity of the LTE base station and the NR RRC entity of the NR base station can independently designate a corresponding base station radio resource control configuration within a range not exceeding the terminal capability. In another example, the LTE RRC entity of the LTE base station and the NR RRC entity of the NR base station may instruct the corresponding base station radio resource control configuration through adjustment. In another example, an LTE RRC entity of an LTE base station may direct LTE base station radio resource control configuration via an LTE radio link and an NR radio link. In another example, the NR RRC entity of the NR base station may direct the LTE base station radio resource control configuration via the NR radio link and the LTE radio link.

If each base station (or terminal) sends one RRC message over two radio links for reliable RRC message transmission (or for any reason), the base station (or terminal) sends the RRC message to two radio links And the corresponding terminal (or base station) should be able to discriminate and process the received signal. The following methods can be used individually or in combination for this purpose.

For convenience of description, the following description will be made of a case where an NR base station (or a terminal) transmits / receives between corresponding terminals (or NR base stations) (for example, when transmitting an NR RRC message through two paths) (For example, an LTE RRC message is forwarded to two paths), another example of MeNB's RRC message is a MeNB-to-UE interface, a SeNB Terminal to the inter-terminal interface) are also included in the scope of the present embodiment.

1. A method of transmitting and receiving through two links in the RRC layer.

The NR RRC entity of the NR base station (or terminal) generates an NR RRC message. Then, the NR RRC message is transmitted through the NR-SRB1 to transmit the generated NR RRC message to the NR base station and the inter-UE wireless link. Or sub-layers. And the NR RRC entity of the NR base station (or terminal) can transmit the NR RRC message to the terminal (or NR RRC) through the LTE base station. For the downlink RRC message, the NR base station (the RRC entity of the NR base station) delivers the NR RRC message including the NR RRC container / NR RRC IEs / NR RRC IEs to the LTE base station. The LTE base station (or the RRC entity of the LTE base station) can transmit an RRC message including the NR RRC container / NR RRC IEs / NR RRC IEs to the UE (or the LTE RRC entity of the UE) through the LTE SRB (LTE SRB1). The LTE RRC entity of the terminal forwards it to the NR RRC entity of the terminal.

The LTE RRC may include an RRC message including a NR RRC container / NR RRC IEs / NR RRC IEs as a transparent container and forward the RRC message to the UE in the RRC reconfiguration message.

In this regard, for example, information for instructing to send the uplink RRC message radio link path to two links may be included in the RRC message and configured in the UE. As another example, information for instructing to copy one uplink RRC message and send it to two links may be included in the RRC message and configured in the terminal. As another example, the RRC message may include indication information for specifying a radio link path of the uplink RRC message to the UE. As another example, information for instructing to copy one uplink RRC message and send it through two radio links may be included in the RRC message and configured in the terminal.

2. A method of transmitting and receiving through two links in the PDCP layer.

The NR RRC entity of the NR base station (or terminal) generates an NR RRC message. Then, the NR RRC message is transmitted through the NR-split SRB1 to transmit the generated NR RRC message to the NR base station and the inter-UE wireless link and between the LTE base station and the inter-UE wireless link. Or sub-layers. The NR RRC entity of the NR base station (or terminal) delivers the generated NR RRC message to the PDCP entity (upper L2 entity).

As an example, a PDCP entity (upper L2 entity) copies a PDCP SDU containing an NR RRC message. Then, the PDCP PDU including one NR RRC message is delivered to the LTE RLC entity. A PDCP PDU containing another NR RRC message is delivered to the NR L2 entity.

Meanwhile, for example, information for instructing to enable the function of sending PDCP data including an uplink RRC message to two radio links in a PDCP (upper L2 entity) may be included in the RRC message and configured in the UE.

Another example is to instruct the upper L2 entity to copy the PDCP SDU / PDU and / or to submit it to the respective lower layer entity to send the PDCP data including the uplink RRC message on the two radio links Information can be included in the RRC message and configured in the terminal.

As another example, the RRC message may include indication information for specifying a radio link path of the uplink RRC message to the UE.

The same copied PDCP data in the peered PDCP entity may be discarded. The base station can configure the UE by instructing the UE to instruct the UE to discard the received PDCP PDU / SDU including the same RRC message.

For another example, the NR RRC entity of the NR base station (or terminal) generates an NR RRC message. And copies it. The NR RRC entity forwards the generated NR RRC message to the NR RRC message through the NR-split SRB 1 to transmit the generated NR RRC message to the NRB inter-UE wireless link and the LTE base station and the inter-UE wireless link. Or sub-layers. The NR RRC entity of the NR base station (or terminal) delivers the generated NR RRC message to the PDCP entity (upper L2 entity). The PDCP entity transmits the PDCP SDU including the received RRC message and the path of the PDCP SDU including the next received RRC message differently from the LTE base station wireless link and the NR base station wireless link.

Here, the case where the NR base station is the master base station has been described as an example, but the same can be applied to the case where the LTE base station is the master base station. In this case, the split SRB may be branched from the PDCP entity of the LTE base station, and the PDCP entity of the LTE base station may perform copying and discarding of the PDCP data.

3. How to add the RRC message identification / sequence number field.

The RRC message is sent over two radio links at the transmitting end for reliable RRC message transmission (or for any reason), and for the same RRC message received over the two radio links, the redundant RRC message at the receiving end is distinguished Duplicate RRC messages can be discarded / dropped / removed / discarded. The base station can configure information for instructing the terminal.

The RRC message at the transmitting end (base station or terminal) may include identification information for distinguishing the same RRC message. For example, identification information for distinguishing RRC messages is incremented each time a new RRC message is generated. And when the largest value is reached, it can be cycled back to the smallest value. For example, if the value is 0 to 3 (or 1 to 4), the first RRC message starts from 0 (or 1) and increases by one. If the third RRC message reaches 3 (or 4) ).

Upon receipt of the RRC message including the same RRC message identification information as that of the previously received RRC message, the receiver (corresponding terminal or base station) can dispatch / drop / remove / discard the corresponding RRC message.

Upon receiving the RRC message including the same RRC message identification information as the previously received RRC message, the receiving end (corresponding terminal or base station) can transmit a confirmation message to the transmitting end.

The base station may configure the terminal with information for instructing to include the RRC message identification information in the RRC message. The UE can recognize that the RRC message identification information is included when the corresponding information is configured.

4. How to use transaction identifier.

The RRC message is sent over two radio links at the transmitting end for reliable RRC message transmission (or for any reason), and for the same RRC message received over the two radio links, the redundant RRC message at the receiving end is distinguished Duplicate RRC messages can be discarded / dropped / removed / discarded. The base station can configure information for instructing the terminal.

The duplicated RRC message can be discriminated and discarded / dropped / removed / discarded by using the Transaction identifier included in the RRC message.

The terminal, if included, sets the RRC transaction Identifier in the response message equal to the RRC transaction Identifier contained in the message received from the base station that triggers the response message.

In order to distinguish the RRC messages that do not trigger the response message from the RRC message, the RRC message that does not trigger the response message can be transmitted including the transaction identifier. For example, a Transaction identifier may be included in a MeasurementReport message. As another example, all RRC messages can be transmitted including a transaction identifier.

Upon receipt of the RRC message including the same Transaction Identifier as the previously received RRC message, the receiving end (corresponding terminal or base station) can dispatch / drop / remove / discard the corresponding RRC message.

When the RRC message including the same RRC message identification information as the previously received RRC message is received by the receiving end (corresponding terminal or base station), the receiving end can transmit an acknowledgment message to the transmitting end.

In the following, an embodiment for configuring dual connectivity and transmitting RRC signaling will be described. That is, specific methods for transmitting the radio resource control signaling to the UE will be described. The following methods can be used independently or in combination for RRC signaling transmission. For convenience of explanation, the signaling radio bearer is described, but the data radio bearer can be configured the same or similar.

1. Using LTE Base Station SRB (Signaling Radio Bearer)

For example, the NR base station can transmit an NR RRC message (for example, an RRC message generated by the NR base station) to the UE through the LTE base station. To this end, the NR base station (or the RRC entity of the NR base station) for the downlink RRC message delivers the NR RRC message including the NR RRC container / NR RRC IEs / NR RRC IEs to the LTE base station. The LTE base station (or the RRC entity of the LTE base station) can transmit an RRC message including the NR RRC container / NR RRC IEs / NR RRC IEs to the UE (or the RRC entity of the UE) through the LTE SRB. The LTE RRC may include an RRC message including a NR RRC container / NR RRC IEs / NR RRC IEs as a transparent container and forward the RRC message to the UE in the RRC reconfiguration message.

This method is advantageous in that the RRC configuration information of the NR base station can be transmitted to the UE while reducing the change of the LTE base station. However, this method increases the delay due to data transmission between the LTE base station and the NR base station. In addition, the NR base station must receive an acknowledgment message of the NR RRC configuration of the UE from the LTE base station. This also causes delays.

For example, when the UE transmits an RRC message including the NR RRC Container / NR RRC IEs / NR RRC IEs to the UE (or the RRC entity of the UE), the LTE base station transmits the RRC entity It may be instructed to transmit a reconfiguration acknowledgment message.

For example, the LTE RRC entity of the UE receiving the RRC message including the NR RRC container / NR RRC IEs / NR RRC IEs through the LTE SRB forwards / submits it to the NR RRC entity. The NR RRC entity applies the new configuration. The NR RRC entity responds with an RRC reconfiguration acknowledgment message through the interface between the UE and the NR base station.

For another example, the RRC entity of the UE receiving the RRC message including the NR RRC container / NR RRC IEs / NR RRC IEs via LTE SRB applies a new configuration. The RRC entity of the UE responds to the RRC reconfiguration acknowledgment message through the interface between the UE and the NR base station.

The RRC reconfiguration message (or the RRC message including the NR RRC container / NR RRC IEs / NR RRC IEs) may include information for indicating this operation of the terminal by the NR base station (or LTE base station).

For example, the RRC reconfiguration message (or the RRC message including the NR RRC container / NR RRC IEs / NR RRC IEs) may include information for instructing the terminal to create / enable / activate the NR RRC entity.

Alternatively, if the UE receives an RRC message (or an RRC message including information indicating the initial NR configuration) including the NR RRC container / NR RRC IEs / NR RRC IEs, The RRC entity may enable / activate the NR additional configuration (or the terminal may establish / create the NR RRC entity).

In another example, if the UE receives an RRC message including information indicating the release of the NR radio resource, the UE can disable / deactivate / release the NR RRC entity.

For example, the RRC reconfiguration message (or the RRC message including the NR RRC container / NR RRC IEs / NR RRC IEs) instructs the terminal to transmit an RRC confirmation message through the interface between the UE and the NR base station in the NR RRC entity Lt; / RTI > information.

For example, the RRC reconfiguration message (or the RRC message including the NR RRC container / NR RRC IEs / NR RRC IEs) may be transmitted from the NR RRC entity to the NR And may include base station SRB configuration information.

2. SRB configuration through NR base station

For example, the NR base station can transmit the NR RRC message to the UE through the interface between the NR base station and the UE. For this purpose, the NR base station can configure the SRB (for example, SRB1) between the UE and the NR base station when configuring the LTE-NR dual connectivity to the terminal (or configuring the NR additional radio resource). This means that the NR base station determines to add SRB (for example, SRB1) between the UE and the NR base station to the corresponding UE and generates configuration information for the SRB. For reference, in the conventional LTE, SRB1 is performed in the RRC connection setup, but SRB1 between the NR base station and the UE (for convenience of description, a signaling radio bearer configured to transmit data through the interface between the NR base station and the UE will be referred to as NR- But not limited to that term.) The configuration can be configured via an RRC reconfiguration message (configuring NR additional radio resources) that make up LTE-NR dual connectivity.

When security is activated, all RRC messages on NR-SRB1 (or SRB1 / SRB2) must be integrity protected and ciphered by PDCP (or L2 entity on NR). LTE-NR dual connectivity may be considered to apply for RRC Connected terminals. Therefore, all RRC messages on the NR-SRB1 must be integrity protected and ciphered by the PDCP (or upper L2 entity on the NR).

To this end, for NR-SRB1, security must always be activated from the start. An LTE base station should not configure its bearer before activating security for this bearer. An LTE base station should not request the addition of NR base stations before activating the security. The NR base station can set NR-SRB1 according to the NR base station addition request of the LTE base station.

For example, when requesting the addition of the NR base station, the LTE base station transmits (or calculates and transmits) the NR base station key (e.g., NR-K _eNB ) to the NR base station. The NR base station selects the integrity protection algorithm and the ciphering algorithm. Then, the selected integrity protection algorithm and the cipher algorithm (or the integrity protection algorithm and the identification information for the cipher algorithm) for serving the NR-SRB1 to the UE are transmitted to the UE through the LTE base station. The LTE base station (or the NR base station) indicates to the terminal a counter (SCG Counter or NR Counter) for calculating a key value associated with the NR-SRB1. The terminal calculates the NR base station key. The terminal _computes a key value (NR-K _RRCint , NR-K _RRCenc ) associated with the NR-SRB1. The UE configures the lower layer (PDCP or L2 entity on the NR) to apply the integrity protection algorithm, the cipher algorithm, NR-K _RRCint , and NR-K _RRCenc .

4 is a diagram illustrating a dual connectivity SRB configuration according to one embodiment.

For example, the L2 entity of the NR 450 of FIG. 4 may be comprised of one or two entities that redistribute the LTE MAC entity functionality of the LTE 400 entity. Although FIG. 4 shows an example in which the LTE-RRC entity and the NR-RRC entity are configured in the terminal 410, the RRC entity / layer in the terminal 410 is also included in the scope of the present invention.

If the RRC entity / layer is configured as one in the UE 410, data can be transmitted through the NR-SRB1 for the RRC message received from the NR base station 450 and for the corresponding response RRC message. If the UE 410 has two RRC entities, data may be transmitted through the NR-SRB1 for the RRC message received from the NR base station 450 and for the response RRC message corresponding thereto. NR base station 450 may preferentially process NR-SRB1 over DRB. For example, it is possible to specify a specific logical channel identification (NRC) value for NR-SRB1. For another example, a logical channel identity value (e.g., 1) such as SRB1 may be specified for NR-splitSRB1. For another example, an SRB-identity value (for example, 1) such as SRB1 can be specified for NR-SRB1. For another example, you can specify a logical / channel configuration value (such as priority (1 or 2), prioritizedBitRate (infinite)) that is the same as / similar to SRB1 for NR-SRB1. In another example, it may include the same logical channel identification information as SRB1 but may include information for identifying the terminal as SCG SRB1.

For example, SRB1 and other logical channel identification information but may include the same logical channel configuration information as SRB1.

The NR base station 450 can perform the NR cell / cell group / transmission point / transmission point group / transmission / reception point / transmission / reception point group / TRP / antenna / antenna group / beam addition / modification / NR RRC message including control information of one or more of resource allocation, NR radio bearer addition / correction / release, NR radio resource configuration, and NR mobility control to the UE 410. The NR base station (or RRC entity of the NR base station) 450 for the downlink RRC message may forward the NR RRC message including the NR RRC container / NR RRC IEs / NR RRC IEs to the UE 410 via NR-SRB1 .

When the UE receives an NR RRC message (for example, an RRC Connection Reconfiguration message) through the NR-SRB 1, the UE can apply the new configuration by using the following methods individually or in combination. The NR RRC message includes radio resource configuration information for the NR base station. For example, as described above, in the case of dual connectivity, the NR RRC message may include secondary base station (NR base station) radio resource configuration information.

2-1) Applying a new configuration through one RRC object in the terminal

The UE can configure NR radio resources through the RRC entity.

In the conventional LTE dual connectivity, when the MeNB sends an RRC message including a new radio resource configuration of the SCG to the UE, if the UE can not comply with the configuration included in the RRC connection reconfiguration message, the UE performs a reconfiguration failure procedure do.

In LTE, the reconfiguration failure procedure is performed as follows.

If the terminal can not comply with the (some) configuration included in the RRC connection reconfiguration message, the terminal continues to use the configuration it uses before receiving the RRC connection reconfiguration message. If security is not activated, it performs an action leaving RRC_CONNECTED with the cause of release as other. Otherwise initiates a connection re-establishment procedure.

As described above, in the conventional LTE, the reconfiguration failure causes a service interruption by switching the terminal into an idle mode or performing an RRC connection reset procedure.

On the other hand, due to the nature of NR, there is room for various reasons to fail in NR radio resource configuration process. Therefore, when a failure occurs in the NR radio resource configuration process for any reason, it may be ineffective to switch the terminal to the idle mode or perform the RRC connection re-establishment procedure.

As an example for improving this, if the UE fails to compose the NR configuration included in the NR RRC message (or can not comply with the NR configuration included in the NR RRC message for any reason), the UE does not trigger the reconfiguration failure procedure . That is, NR RRC configuration failure can be prevented from triggering LTE RRC configuration failure. For example, if the NR RRC configuration fails, the UE transmits an RRC message (for example, an SCG failure information message, a UE assistance message, or an NR failure information / NR status message to be newly defined) including the cause of the NR RRC configuration failure to the NR base station Lt; / RTI > For example, if the NR RRC configuration fails, the UE transmits an RRC message (for example, an SCG failure information message, a UE assistance message, or an NR failure information / NR status message to be newly defined) including the cause of the NR RRC configuration failure to the LTE base station Lt; / RTI > That is, when the UE fails to configure the radio resource of the secondary base station using the RRC message received through the SRB of the secondary base station, the UE can transmit the failure information to the master base station.

Hereinafter, this will be described in more detail.

The received RRC message includes configuration information (e.g., NR cell configuration information, NR bearer configuration information, control information for NR random access, NR measurement configuration information, NR mobility control, and NR radio resources And one or more pieces of configuration information). Hereinafter, for convenience of explanation, configuration information for further modifying NR base stations in dual connectivity or information for reconstructing NR radio resources through the secondary base station SRB is referred to as secondary base station radio resource configuration information, NR radio resource configuration information, NR configuration information Or configuration information.

For example, when the RRCConnectionReconfiguration message received through the master base station SRB includes NR radio resource configuration information, the terminal (e.g., terminal RRC entity) performs the NR configuration.

As another example, when the RRCConnectionReconfiguration message received through the secondary base station SRB includes the NR radio resource configuration information, the terminal (e.g., the terminal RRC entity) performs the NR configuration.

In each of the examples described above, if the UE can not comply with the NR configuration, the UE continues to use the (NR) configuration prior to receiving the RRC connection reconfiguration message (before receiving the NR configuration information).

Alternatively, if the terminal (RRC) can not comply with the NR configuration, suspend / suspend / suspend / release use of NR radio resources. The NR radio resource may include at least one of a secondary cell group DRB (Data Radio Bearer), a secondary cell group SRB, a secondary cell group portion of a split DRB, and a secondary cell group portion of a split SRB.

Or if the terminal (RRC) can not comply with the NR configuration, the RRC sends an RRC message to the LTE base station including the cause of the NR RRC configuration failure. The LTE base station delivers this to the NR base station.

Alternatively, if the RRC can not comply with the NR configuration, the RRC may directly transmit an RRC message including the cause of the NR RRC configuration failure to the NR base station through the interface between the terminal and the NR base station.

2-2) Applying a new configuration through two RRC objects in the terminal

As described above, NRs can independently include LTE and other evolutionary features. The LTE RRC and the NR RRC can be configured to effectively implement this in the terminal.

In the conventional LTE dual connectivity, when the MeNB sends an RRC message including a new radio resource configuration of the SCG to the UE, if the UE can not comply with the configuration included in the RRC connection reconfiguration message, the UE performs a reconfiguration failure procedure do. In LTE, the reconfiguration failure procedure is performed as follows.

If the terminal can not comply with the (some) configuration included in the RRC connection reconfiguration message, the terminal continues to use the configuration it uses before receiving the RRC connection reconfiguration message. If security is not enabled, it performs an action that leaves RRC_CONNECTED with the cause of the release as other. Otherwise initiates a connection re-establishment procedure.

As described above, in the conventional LTE, the reconfiguration failure causes a service interruption by switching the terminal into an idle mode or performing an RRC connection reset procedure.

On the other hand, due to the nature of NR, there is room for various reasons to fail in NR addition process. Therefore, it is inefficient to switch the terminal to the idle mode or perform the RRC connection reset procedure when a failure occurs in the NR addition process for any reason.

In order to improve this, for example, the UE may not trigger the reconfiguration failure procedure if the NR configuration included in the NR RRC message fails (or can not comply with the NR configuration included in the NR RRC message for some reason) . NR RRC configuration failure may not trigger LTE RRC configuration failure. If the NR RRC configuration fails, the UE transmits an RRC message (for example, an SCG failure information message, a UE assistance message, an NR failure information / NR status message to be newly defined) including the cause of the NR RRC configuration failure to the NR base station As shown in FIG. Or if the terminal (RRC) can not comply with the NR configuration, the RRC sends an RRC message to the LTE base station including the cause of the NR RRC configuration failure. The LTE base station delivers this to the NR base station.

Hereinafter, this will be described in more detail.

If the received RRCConnectionReconfiguration message includes configuration information for configuring NR radio resources, the terminal (NR RRC) performs the NR configuration.

Alternatively, if the terminal (NR RRC) can not comply with the NR configuration, the terminal continues to use the (NR) configuration before receiving the RRC connection reconfiguration message (before the NR RRC receives the NR configuration information).

Or if the terminal (NR RRC) can not comply with the NR configuration, suspend / stop / suspend / release NR radio resource use. The NR radio resource may include at least one of a secondary cell group DRB (Data Radio Bearer), a secondary cell group SRB, a secondary cell group portion of a split DRB, and a secondary cell group portion of a split SRB.

Alternatively, if the terminal (NR RRC) can not comply with the NR configuration, it releases the NR radio resource

Alternatively, if the terminal (NR RRC) can not comply with the NR configuration, the NR RRC indicates an NR reconfiguration failure to the LTE RRC. The LTE RRC sends an RRC message to the LTE base station that includes the cause of the NR RRC configuration failure. The LTE base station delivers this to the NR base station.

Alternatively, if the terminal (NR RRC) can not comply with the NR configuration, the NR RRC directly transmits an RRC message including the cause of the NR RRC configuration failure to the NR base station through the interface between the terminal and the NR base station.

Another example of NR radio link failure will be described below.

When a radio link problem (failure) is detected on the NR physical layer, the UE can point the NR physical layer failure to the RRC entity. The RRC entity may indicate to the LTE base station via the LTE SRB an RRC message containing the cause of the failure for the NR physical layer failure.

3. SRB configuration through NR base station and LTE base station

The NR may include LTE and other wireless communication features, and the LTE base station may not understand the RRC message generated by the NR base station.

The NR base station includes NR cell / cell group / transmission point / transmission point group / transmission / reception point / transmission / reception point group / TRP / antenna / antenna group / beam addition / modification / release / management, NR measurement, NR measurement report, NR resource allocation, The NR RRC message including at least one control information of NR radio bearer addition / correction / release, NR radio resource configuration, and NR mobility control may be directly sent to the UE.

However, NR can be constructed even at high frequencies (e.g., high frequencies above 6 GHz). In this case, fast SINR drops may occur depending on the link blocking factor in the high frequency band and high transmission loss. And can cause problems when sending NR RRCs. To overcome this problem, NR RRC messages can be sent using both the NR base station and the terminal interface, and the LTE base station and the terminal interface.

5 is a diagram illustrating a dual connectivity SRB configuration according to another embodiment.

Referring to FIG. 5, when configuring the LTE-NR dual connectivity (or configuring the NR additional radio resource) to the UE 510, the NR base station 550 determines whether the UE 510 is an LTE base station (E.g., SRB1 type) that can use both the SRB 500 and the NRB 550. An SRB that can use both the LTE base station 500 and the NR base station 550 (for convenience of description, a signaling radio bearer configuring the NR base station to use both the LTE base station and the NR base station will be referred to as NR-split SRB1 hereinafter) .) Configuration can be configured through an RRC reconfiguration message (re-configuring LTE-NR dual connectivity) (configuring NR additional radio resources).

When security is activated, all RRC messages on NR-splitSRB1 must be integrity protected and ciphered by PDCP (or L2 entity on NR). The LTE-NR dual connectivity may be considered to apply to the RRC Connected terminal 510. Therefore, all RRC messages on NR-splitSRB1 must be integrity protected and ciphered by PDCP (or L2 entity on top of NR).

To this end, for NR-splitSRB1, security must always be activated from the start. NR base station 550 should not set this bearer until it activates security. The LTE base station 500 should not request the addition of the NR base station 550 before activating the security. Or the NR base station 550 should not request the addition of NR-split SRB1 to the LTE base station 500 before activating the security. The NR base station 550 can set NR-split SRB1 according to the NR base station addition request of the LTE base station 500. [ Or the NR base station 550 may set NR-split SRB1 as needed.

For example, when requesting the addition of the NR base station, the LTE base station 500 transmits (or calculates and delivers) the NR base station key (NR-K _eNB ) to the NR base station 550, for example. The NR base station 550 selects the integrity protection algorithm and the cipher algorithm. The selected integrity protection algorithm and the cipher algorithm (or the integrity protection algorithm and the identification information about the cipher algorithm) to service the NR-splitSRB1 are transmitted to the terminal 510 through the LTE base station 500 do. The LTE base station 500 (or NR base station 550) indicates a counter (SCG Counter or NR Counter) for the terminal 510 to calculate a key value associated with the NR-split SRB1. The terminal 510 calculates the NR base station key. The UE 510 calculates a key value (NR-K _RRCint , NR-K _RRCenc ) associated with the NR-SRB1. The UE 510 configures the lower layer (the L2 entity on the PDCP or the NR) to apply the integrity protection algorithm, the cipher ring algorithm, the NR-K _RRCint , and the NR-K _RRCenc .

For example, the NR base station 550 may instruct the LTE base station 500 to configure NR-split SRB1. The LTE base station 500 may not understand the NR RRC container / NR RRC IEs of the NR base station 550 as described above. Therefore, the NR base station 550 may include in the signaling message on the interface between the NR base station 550 and the LTE base station 500 information for instructing the LTE base station 500 to configure the NR-split SRB1. Upon receiving the information for instructing the LTE base station 500 to configure the NR-split SRB1, the LTE base station 500 can instruct the terminal 510 to configure NR-split SRB1. The LTE base station 500 may instruct the terminal 510 to process the NR-split SRB1 in preference to the DRB. For example, a specific logical channel identity value may be specified for NR-splitSRB1. The terminal 510 can preferentially process the logical channel specified by the NR-split SRB1 in comparison with the DRB. For another example, a logical channel identification (logical channel identification) value (1) such as SRB1 can be specified for NR-splitSRB1. For another example, NR-splitSRB1 can be instructed to be processed with the same priority as SRB1. For another example, it may indicate information to indicate that it is a signaling bearer for NR-splitSRB1. For another example, NR-splitSRB1 may be assigned a different logical channel identity value than SRB1, but may specify information to be processed with the same priority as SRB1. For example, the same logical channel configuration information as SRB1. For another example, an SRB-identity value (e.g., 1) such as SRB1 may be specified for NR-splitSRB1. For another example, you can specify a similar / similar logical channel configuration value (for example, priority (1 or 2), prioritizedBitRate (infinite)) to SRB1 for NR-splitSRB1. Other examples include the same logical channel identification information as SRB1, but the terminal may include information for identifying entities for NR-split SRB1.

For example, SRB1 and other logical channel identification information but may include the same logical channel configuration information as SRB1.

4. SRB configuration through LTE base station and NR base station

The NR may include LTE and other wireless communication features, and the LTE base station may not understand the RRC message generated by the NR base station.

The NR base station includes NR cell / cell group / transmission point / transmission point group / transmission / reception point / transmission / reception point group / TRP / antenna / antenna group / beam addition / modification / release / management, NR measurement, NR measurement report, NR resource allocation, An NR RRC message including control information of at least one of NR radio bearer addition / correction / release, NR radio resource configuration, and NR mobility control to the UE directly.

However, NR can be constructed even at high frequencies (e.g., high frequencies above 6 GHz). In this case, high SINR drops may occur due to high link loss and high transmission loss, and may cause problems when sending NR RRC. To overcome this problem, NR RRC messages can be sent using both the NR base station and the terminal interface, and the LTE base station and the terminal interface.

On the other hand, it may be desirable to transmit some uplink or downlink RRC messages first through the LTE base station for reliability.

6 is a diagram illustrating a dual connectivity SRB configuration according to another embodiment.

Referring to FIG. 6, when LTE-NR dual connectivity is configured in the terminal 610 (when NR additional radio resources are configured), the LTE base station 600 determines that the terminal 610 is an LTE base station 600, (For example, SRB1 type) capable of using both NRBs 650 and NRBs 650 can be configured. An SRB that can use both the LTE base station 600 and the NR base station 650 (hereinafter, a signaling radio bearer for configuring the LTE base station to use both the LTE base station and the NR base station for convenience of description is referred to as LTE-splitSRB1) .) Configuration can be configured through an RRC reconfiguration message (re-configuring LTE-NR dual connectivity) (configuring NR additional radio resources).

All RRC messages on LTE-splitSRB1 must be integrity protected and ciphered by PDCP.

For this, for LTE-splitSRB1, security must always be activated from the start. The LTE base station 600 should not set this bearer until it activates the security. The LTE base station 600 should not request the addition of the NR base station 650 before activating the security. The NR base station 650 may set the NR configuration for the LTE-split SRB1 according to the indication information included in the NR base station addition request of the LTE base station 600. [

For example, when requesting the addition of the NR base station, the LTE base station 600 delivers the information for instructing the LTE-split SRB1 to the NR base station 650 to configure. The NR base station 650 transmits information (e.g., one or more of logaical channel configuration, logical channel identity, and rlcconfig) for configuring the NR part of the LTE-split SRB1 to the terminal 610 through the LTE base station 600. [ For example, the NR base station 650 may instruct the LTE base station 600 to confirm the configuration of the LTE-split SRB1. The LTE base station 600 may not understand the NR RRC container / NR RRC IEs of the NR base station 650 as described above. Therefore, the NR base station 650 may include in the signaling message on the interface between the NR base station 650 and the LTE base station 600 the indication information for confirming the LTE-split SRB1 configuration to the LTE base station 600. [ Upon receiving the information for instructing the LTE base station 600 to configure the LTE-split SRB1, the LTE base station 600 can instruct the terminal 610 to configure the LTE part of the LTE-split SRB1. The LTE base station 600 may preferentially process LTE-splitSRB1 over DRB. For example, it is possible to specify a specific logical channel identity value for LTE-splitSRB1. The terminal 610 can preferentially process the logical channel specified by the LTE-splitSRB1 in comparison with the DRB. For another example, a logical channel identification (logical channel identification) value (1) such as SRB1 can be specified for NR-splitSRB1 (or SRB1 or SRB2).

NR base station 650 may preferentially process LTE-split SRB1 over DRB. For example, it is possible to specify a specific logical channel identity value for LTE-splitSRB1. The terminal 610 can preferentially process the logical channel specified by the LTE-splitSRB1 in comparison with the DRB. For another example, a logical channel identification value (1) such as SRB1 may be specified for LTE-splitSRB1 (or may be configured as SRB1 or SRB2). For another example, for LTE-splitSRB1, It is possible to indicate information for processing with the same priority. For another example, it may indicate information to indicate that it is a signaling bearer for LTE-splitSRB1. For another example, an SRB-identity value (e.g., 1) such as SRB1 may be specified for LTE-splitSRB1. For another example, you can specify a similar / similar logical channel configuration value (for example, priority (1 or 2), prioritizedBitRate (infinite)) to SRB1 for LTE-splitSRB1. As another example, LTE-splitSRB1 can be processed like SRB1, so that it may not have a separate configuration. Other examples include the same logical channel identification information as SRB1 but may include information for the terminal to identify entities for LTE-split SRB1.

For example, SRB1 and other logical channel identification information but may include the same logical channel configuration information as SRB1.

However, the LTE base station 600 is configured to designate the path of the RRC signaling message in the PDCP entity as the LTE base station 600 and the NR base station 650 (or LTE base station 600 and NR base station 650 and two base stations) Information can be instructed to the terminal.

Hereinafter, a processing method when the UE receives different RRC messages will be described in detail.

Through the above-described embodiments, the LTE radio resource control entity of the LTE base station and the NR radio resource entity of the NR base station can independently designate the corresponding base station radio resource control configuration. Alternatively, the LTE radio resource control entity of the LTE base station and the NR radio resource entity of the NR base station can independently designate the corresponding base station radio resource control configuration within a range not exceeding the terminal capability through the above-described embodiments. Alternatively, through the above-described embodiments, the LTE radio resource control entity of the LTE base station and the NR radio resource entity of the NR base station can instruct the corresponding base station radio resource control configuration through adjustment. Alternatively, through the above-described embodiments, the LTE radio resource control entity of the LTE base station can instruct the LTE base station radio resource control configuration through the LTE radio link and the NR radio link. Or, through the embodiments described above, the NR radio resource control entity of the NR base station may indicate the LTE base station radio resource control configuration through the NR radio link and the LTE radio link.

The LTE base station can instruct the UE to indicate an NRC base station radio resource configuration (related to the NR base station radio resource configuration or affecting NR base station radio resource configuration) to the UE. For example, the LTE base station may transmit an RRC message to the terminal, which includes information indicating an NR-configuration release of the NR base station.

For example, if the UE is set to release the NRB radio resource in the RRC message received from the LTE base station, the UE releases the entire NRB radio resource except for the DRB configuration. If the current terminal configuration includes one or more split or SCG DRBs and the received RRC reconfiguration message includes radio resource configuration dedicated information including further modified DRB information (drb-ToAddModList) Reconfigure split or SCG DRB.

As another example, if the UE is set to release the NR base station radio resource in the RRC message received from the LTE base station, the UE releases the entire NR base station radio resource.

When the LTE base station indicates to the UE an RRC message indicating the NR radio resource configuration (affecting NR radio station configuration related to the NR radio station configuration), the NR base station indicates the NR radio station configuration RRC message to the UE.

For example, the NR base station may include one or more of NR radio resources, NR radio resource configuration, NR radio resource configuration, NR radio resource configuration, NR radio resource allocation, NR radio resource allocation, The RRC message indicating the resource configuration can be instructed to the terminal.

For example, the UE may receive another RRC message before it receives one RRC message and completes its application.

1. When receiving an NR radio resource release from an LTE base station

If the UE configures the NR base station radio resource according to the RRC message received from the NR base station, the UE transmits an RRC message including information for instructing release of the NR base station radio resource (NR-configuration) from the LTE base station The UE can perform one or more of the following operations.

- The UE can perform radio resource release of the NR base station.

- The terminal uses the RRC message before it receives the RRC message that is being executed when the radio resource release of the NR base station is received from the LTE base station by stop / stop / cancel / hold / drop / pause / override / , And can release the radio resource of the NR base station.

- The terminal uses the RRC message that is received from the LTE base station after the release of the radio resource of the NR base station is stopped, stopped, canceled / pending / dropped / paused / overridden / To the NR base station, an RRC message including information indicating that a return has occurred.

- The radio resource of the NR base station can be configured sequentially in order of the RRC message received in the terminal. Accordingly, the UE can receive the RRC message, complete the operation for configuring the RRC message, and perform radio resource release of the NR base station.

If the NRB radio resource is set to be released in the RRC message received from the LTE base station, the UE releases the entire NR base station radio resource except for the DRB configuration.

- If the current terminal configuration includes one or more split or SCG DRBs and the received RRC reconfiguration message contains radio resource configuration dedicated information including additional modified DRB information (drb-ToAddModList) Reconfigure split or SCG DRB accordingly.

The base station (LTE base station or NR base station) can be configured by instructing the terminal to instruct the above-mentioned operation.

2. When receiving an NR radio resource release from the NR base station

If the UE configures the NRB radio resource according to the RRC message received from the LTE base station, the UE transmits an RRC message including information for instructing release of the NR base station radio resource (NR-configuration) from the NR base station The UE can perform one or more of the following operations.

- The UE can perform radio resource release of the NR base station.

- The UE uses the RRC message before it receives the RRC message that is being executed when it is received from the NR base station and the RRC message being executed is received / suspended / , And can release the radio resource of the NR base station.

- The terminal uses the NR radio base station radio resource release from the NR base station before it receives the RRC message that is being executed and stops the operation of the RRC message which is being executed, such as stop / stop / cancel / hold / drop / pause / To the LTE base station, an RRC message including information indicating that a feedback has occurred.

- The radio resource of the NR base station can be configured sequentially in order of the RRC message received in the terminal. Accordingly, the UE can receive the RRC message, complete the operation for configuring the RRC message, and perform radio resource release of the NR base station.

If the radio resource of the NR base station is set to be released in the RRC message received from the NR base station, the UE releases the entire NR base station radio resource except for the DRB configuration.

- If the current terminal configuration includes one or more split or SCG DRBs and the received RRC reconfiguration message contains radio resource configuration dedicated information including additional modified DRB information (drb-ToAddModList) Reconfigure split or SCG DRB accordingly.

The base station (LTE base station or NR base station) can be configured by instructing the terminal to instruct the above-mentioned operation.

3. When receiving different RRC messages except for releasing NR radio resources

If the UE configures the NRB radio resource in accordance with the RRC message received from the LTE base station, the RRC including the information for instructing the NR base station to add / modify / configure the NR base station radio resource (NR-configuration) Message, the terminal may perform one or more of the following operations. (Or information for instructing the UE to add / modify / configure the NR base station radio resource (NR-configuration) from the LTE base station when the UE configures the NR base station radio resource according to the RRC message received from the NR base station The UE can perform one or more of the following operations:

- The radio resource of the NR base station can be configured sequentially in order of the RRC message received in the terminal. Accordingly, the UE receives the RRC message and completes the operation for configuring the RRC message, and can perform radio resource configuration of the NR base station according to the received RRC message.

- to process the RRC message received from the master base station (e.g., LTE base station) first. The UE informs the secondary base station (for example, the NR base station) that the RRC configuration instruction is used before the reception of the RRC message in suspension / stop / cancel / hold / drop / To a secondary base station (e.g., an NR base station).

- It is possible to preferentially process the RRC message received from the NR base station. The UE transmits an RRC message including information indicating that a return to the configuration used by the LTE base station before the RRC configuration indication is received before receiving the RRC message of stop / stop / cancel / hold / drop / override / NR base station.

The base station (LTE base station or NR base station) can be configured by instructing the terminal to instruct the above-mentioned operation.

As described herein, the present disclosure provides an effect of minimizing unnecessary waste of radio resources and data processing time when the UE performs data redundancy transmission through a plurality of different radio paths. In addition, the present disclosure has an effect that the terminal can process the duplicated transmission efficiently through two different radio paths. LTE-NR LTE-NR for tight interworking between NRs, can effectively handle radio resource control signaling of NR base stations for dual connectivity operation. Also, there is an effect that the base station can distinguish RRC messages using two different radio access links.

Hereinafter, a terminal and a base station apparatus capable of performing a part or all of the embodiments described with reference to Figs. 1 to 6 will be described with reference to the drawings.

7 is a diagram for explaining a terminal configuration according to an embodiment.

Referring to FIG. 7, a UE 700 having a dual connection configured to transmit data redundantly includes an RRC (Radio Resource Control) module 700 including configuration information for configuring redundant transmission in a PDCP (Packet Data Convergence Protocol) Control unit 730 for receiving indication information indicating whether to activate the PDCP entity for the redundant transmission operation of the PDCP entity configured by the base station, and a controller for configuring the redundant transmission in the PDCP entity for the at least one radio bearer 710) and a transmitter 720 for copying a PDCP PDU (Protocol Data Unit) from a PDCP entity and transferring the PDCP PDU to different RLC (Radio Link Control) entities to transmit the same data to a plurality of base stations 720 ).

The controller 710 can configure a dual connection (dual connectivity) with a plurality of base stations. The plurality of base stations can be set to use different radio access technologies. For example, the master base station may be the gNB using the NR radio access technology described above, and the secondary base station may be the eNB using the LTE radio access technology. Or the master base station may be an eNB using LTE radio access technology and the secondary base station may be a gNB using NR radio access technology. Or both the master base station and the secondary base station may be gNBs using NR radio access technology.

In addition, the controller 710 may configure the PDCP entity to transmit data having the same PDCP SN on a plurality of paths based on the configuration information. The controller 710 configures redundant transmission in the PDCP entity, and configures the redundant transmission in the inactive state. Alternatively, the control unit 710 may configure the redundant transmission function in the PDCP entity to be in an active state.

Meanwhile, the configuration information received by the receiver 730 may include specific information for supporting the redundant transmission function in the PDCP entity. For example, the configuration information includes a processing operation when duplicated data is received from the PDCP entity, a processing operation when the redundant transmission function is activated or not, and a processing operation when the PDCP entity receives data having the same PDCP SN through two paths And may include information for configuring the terminal so that at least one operation among the operations to be performed can be performed.

Also, the receiver 730 can receive the instruction information through the Medium Access Control Element (MAC). The indication information may include information indicating whether the redundant transmission function of the PDCP entity configured in the terminal is changed to the active state or the inactive state. If the indication information indicates activation, the MAC entity of the UE can instruct the upper layer to activate the redundancy transmission operation of the PDCP entity. That is, when the indication information received through the MAC CE indicates the activation of the redundant transmission function, the MAC entity of the UE can transmit the indication to the upper layer (for example, the RRC layer) and instruct the upper layer.

When the instruction information instructs activation, the transmitting unit 820 transmits PDCP PDUs copied from the PDCP entity to different RLC (Radio Link Control) entities, thereby transmitting the same data to a plurality of base stations .

For example, when the redundant transmission function of the PDCP entity configured in the UE is configured (or changed) by the above-described indication information, the PDCP entity copies the data for transmission to the Node B, RLC entity, the transmitter 820 can transmit the same data to the base station through a plurality of radio paths.

Meanwhile, a plurality of RLC entities may be configured in the UE for each BS constituting the dual connection, and may be associated with one PDCP entity. The PDCP entity may transmit a PDCP PDU to any one of a plurality of RLC entities when the indication information indicates inactivation and a redundant transmission operation of the PDCP entity is configured in the terminal. That is, when the UE is configured to have a redundant transmission function in the PDCP entity but the corresponding function is in the inactive state, the PDCP entity transmits data to only one of the plurality of RLC entities configured for dual connection, ) Can perform data transmission over a single path.

On the other hand, the above-mentioned redundant transmission function may be configured only for the data radio bearer (DRB). For example, the redundant transmission function on the PDCP entity is not configured for the signaling radio bearer, but can only be configured for the data radio bearer.

In addition, the indication information may indicate whether to enable the PDCP entity to perform a redundant transmission operation for each of the one or more data radio bearers. For example, the indication information may include information on whether to enable the redundant transmission function in the PDCP entity for each data radio bearer configured in the UE. In this case, the PDCP redundancy transmission function is activated for the specific data radio bearer, but the PDCP redundancy transmission function can be indicated to be inactivated for other data radio bearers. The above-mentioned base station may be a master base station or a secondary base station.

In addition, the control unit 710 controls the overall operation of the terminal 700 in accordance with the above-described exemplary embodiments by forming a double connection with a plurality of base stations and transmitting data to the base station in a redundant manner . The receiving unit 730 receives the downlink control information, data, and a message from the base station through the corresponding channel, and the transmitting unit 720 transmits the uplink control information, data, and message to the base station through the corresponding channel.

8 is a diagram for explaining a base station configuration according to an embodiment.

Referring to FIG. 8, a base station 800 that forms a dual connection with a terminal and receives data redundantly constitutes a redundant transmission in a PDCP (Packet Data Convergence Protocol) entity of the terminal for one or more radio bearers A transmitter 820 for transmitting an RRC (Radio Resource Control) message including configuration information for the PDCP entity to the UE, a transmitter 820 for transmitting indication information indicating whether to activate the redundant transmission operation of the configured PDCP entity, A receiver 830 for receiving data copied from the PDCP entity of the UE through the RLC entity of the base station and the RLC entity of another base station constituting the dual connection to the UE.

As described above, the control unit 810 can form a dual connection to the terminal together with other base stations. In addition, the base stations constituting the dual connection can be configured to use different radio access technologies.

The transmitting unit 820 may transmit an RRC message including configuration information for configuring redundant transmission in the PDCP entity of the UE to one or more radio bearers to the UE. For example, the configuration information may include specific information for supporting the redundant transmission function in the PDCP entity. For example, the configuration information includes a processing operation when duplicated data is received from the PDCP entity of the terminal, a processing operation when the redundant transmission function is activated or not, and a processing operation when the PDCP entity of the terminal receives the same PDCP SN through two paths And information for configuring the terminal so that at least one operation among the operations for transmitting the data having the same information can be performed.

In addition, the transmitting unit 820 may perform a step of transmitting indication information indicating whether to activate the redundant transmission operation of the configured PDCP entity (S320). For example, the indication information may be transmitted through a Medium Access Control Element (MAC). The indication information may include information indicating whether the redundant transmission function of the PDCP entity configured in the terminal is changed to the active state or the inactive state.

When the instruction information indicates activation, the receiving unit 830 can duplicate the data copied from the PDCP entity of the UE through the RLC entity of the base station and the RLC entity of another base station constituting the dual connection to the UE . In this case, the UE copies the PDCP PDU (Protocol Data Unit) from the PDCP entity of the UE and transfers the PDCP PDU to the different RLC entity configured in the UE, so that the Node B 800 duplicates the same data through a plurality of RLC entities So that it can be received. A plurality of RLC entities configured in the UE may be configured in the UE for each BS configuring the dual connection, and may be linked to one PDCP entity. Similarly, the PDCP entity of the base station 800 may be associated with the RLC entity of the corresponding base station 800 and may also be associated with the RLC entity of the other base station constituting the dual connection. Specifically, the receiving unit 830 receives data through the radio resource between the base station and the terminal, and can receive the same data from other base stations through the inter-base station interface. Alternatively, if the indication information indicates inactivation and the PDCP entity is configured for a redundant transmission operation, the receiver 830 can receive data only through the RLC entity of the base station.

On the other hand, the above-mentioned redundant transmission function may be configured only for the data radio bearer (DRB). For example, the redundant transmission function on the PDCP entity is not configured for the signaling radio bearer, but can only be configured for the data radio bearer.

In addition, the indication information may indicate whether to enable the PDCP entity to perform a redundant transmission operation for each of the one or more data radio bearers. For example, the indication information may include information on whether to enable the redundant transmission function in the PDCP entity for each data radio bearer configured in the UE. In this case, the PDCP redundancy transmission function is activated for the specific data radio bearer, but the PDCP redundancy transmission function can be indicated to be inactivated for other data radio bearers.

In addition, the control unit 810 may be configured to form a dual connection to a plurality of base stations and a terminal according to the above-described exemplary embodiments, to control uplink data transmission of the terminal, to receive redundantly transmitted data And controls the operation of the base station 800 as a whole. The transmitting unit 820 and the receiving unit 830 are used to transmit and receive signals, messages, and data necessary for performing the above-described embodiments to and from the terminal and the secondary base station.

The standard content or standard documents referred to in the above-mentioned embodiments constitute a part of this specification, for the sake of simplicity of description of the specification. Therefore, it is to be understood that the content of the above standard content and portions of the standard documents are added to or contained in the scope of the present invention.

The foregoing description is merely illustrative of the technical idea of the present invention, and various changes and modifications may be made by those skilled in the art without departing from the essential characteristics of the present invention. Therefore, the embodiments disclosed in the present invention are intended to illustrate rather than limit the scope of the present invention, and the scope of the technical idea of the present invention is not limited by these embodiments. The scope of protection of the present invention should be construed according to the following claims, and all technical ideas within the scope of equivalents should be construed as falling within the scope of the present invention.

Claims (22)

A method for redundant data transmission in a terminal having a dual connection,
Receiving a Radio Resource Control (RRC) message including configuration information for configuring redundant transmission in a Packet Data Convergence Protocol (PDCP) entity from a base station;
Configuring redundant transmissions on the PDCP entity for one or more radio bearers;
Receiving, from the base station, indication information indicating whether to activate the redundant transmission operation of the configured PDCP entity; And
And copying the PDCP PDU (Protocol Data Unit) from the PDCP entity to another RLC entity when the indication information indicates activation, thereby duplicatively transmitting the same data to the plurality of base stations Way. The method according to claim 1,
The terminal configured with the double connection,
And configured to transmit and receive data to and from the plurality of base stations set to use different radio access technologies. The method according to claim 1,
The instruction information includes:
Characterized in that it is received via a MAC Control Element (MAC). The method according to claim 1,
Wherein the step of receiving the instruction information comprises:
And when the indication information indicates activation, the MAC entity indicates to the upper layer the activation of the redundant transmission operation of the PDCP entity. The method according to claim 1,
Wherein the PDCP entity comprises:
Wherein the PDCP PDU is delivered to any one of the plurality of RLC entities when the indication information indicates inactivation and the PDCP entity is configured to perform a redundant transmission operation. The method according to claim 1,
Wherein the one or more radio bearers are data radio bearers,
Wherein the indication information indicates whether or not to activate the redundant transmission operation of the PDCP entity in each of the one or more data radio bearers. A method for receiving data redundantly by a base station having a dual connection with a terminal,
Transmitting a Radio Resource Control (RRC) message including configuration information for configuring redundant transmission in a Packet Data Convergence Protocol (PDCP) entity of the UE to one or more radio bearers to the UE;
Transmitting indication information indicating whether to activate the redundant transmission operation of the configured PDCP entity; And
If the indication information indicates activation, duplicating data received from the PDCP entity of the UE through the RLC entity of the base station and the RLC entity of another base station constituting a dual connection to the UE How to. 8. The method of claim 7,
The other base station,
Wherein the base station is configured to use a different radio access technology than the base station and to configure the dual connection with the base station for the terminal. 8. The method of claim 7,
The instruction information includes:
And transmitted via a MAC Control Element (MAC). 8. The method of claim 7,
The PDCP entity of the base station,
Wherein the data is received only through the RLC entity of the base station when the indication information indicates inactivation and a redundant transmission operation of the PDCP entity is configured in the UE. 8. The method of claim 7,
Wherein the one or more radio bearers are data radio bearers,
Wherein the indication information indicates whether or not to activate the redundant transmission operation of the PDCP entity in each of the one or more data radio bearers. In a terminal having a dual connection configured to transmit data redundantly,
Receiving an RRC (Radio Resource Control) message including configuration information for configuring redundant transmission in a Packet Data Convegence Protocol (PDCP) entity from a base station, receiving an RRC (Radio Resource Control) message from the base station, A reception unit for receiving the instruction information indicating whether or not the received instruction information is present;
A controller for configuring redundant transmissions on the PDCP entity for one or more radio bearers; And
And a transmitter for copying the PDCP PDU (Protocol Data Unit) from the PDCP entity to the different RLC (Radio Link Control) entity when the indication information indicates activation, and transmitting the identical data to the plurality of base stations Terminal. 13. The method of claim 12,
The terminal configured with the double connection,
And configured to transmit and receive data with the plurality of base stations set to use different radio access technologies. 13. The method of claim 12,
The instruction information includes:
(MAC Control Element). ≪ Desc / Clms Page number 13 > 13. The method of claim 12,
Wherein,
And controls the MAC entity to indicate an activation of a redundant transmission operation of the PDCP entity to an upper layer when the indication information indicates activation. 13. The method of claim 12,
Wherein the PDCP entity comprises:
Wherein the PDCP entity transfers the PDCP PDU to any one of the plurality of RLC entities when the indication information indicates inactivation and a redundant transmission operation of the PDCP entity is configured. 13. The method of claim 12,
Wherein the one or more radio bearers are data radio bearers,
Wherein the indication information indicates whether or not to activate the redundant transmission operation of the PDCP entity to each of the one or more data radio bearers. 1. A base station for establishing a dual connection with a terminal and receiving data redundantly,
A Radio Resource Control (RRC) message including configuration information for configuring redundant transmission in a Packet Data Convegence Protocol (PDCP) entity of one or more RBs of a UE to a UE, A transmission unit for transmitting indication information indicating whether to activate the redundant transmission operation; And
And a receiving unit for receiving data copied and transmitted from the PDCP entity of the UE through the RLC entity of the base station and the RLC entity of another base station constituting the dual connection to the UE when the indication information indicates activation . 19. The method of claim 18,
The other base station,
Wherein the base station is configured to use a different radio access technology than the base station and to configure the dual connection with the base station for the terminal. 19. The method of claim 18,
The instruction information includes:
And a MAC Control Element (MAC). 19. The method of claim 18,
The PDCP entity of the base station,
Wherein the data is received only through the RLC entity of the base station when the indication information indicates inactivation and the PDCP entity is configured to perform a redundant transmission operation on the UE. 19. The method of claim 18,
Wherein the one or more radio bearers are data radio bearers,
Wherein the indication information indicates whether or not to activate the redundancy transmission operation of the PDCP entity in each of the one or more data radio bearers.

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