KR102016728B1 - Methods for controlling a data redundant transmission and Apparatuses thereof - Google Patents

Abstract

The present disclosure relates to a specific method and apparatus therefor for redundantly transmitting dual or multi connectivity based data. According to an embodiment of the present invention, in a method of duplex transmission of data by a terminal having dual connectivity, radio resource control including configuration information for configuring redundant transmission in a Packet Data Convegence Protocol (PDCP) entity from a base station ) Receiving the message, configuring redundant transmission in the PDCP entity for one or more radio bearers, receiving indication information indicating whether activation of the redundant transmission operation of the configured PDCP entity from the base station and the indication information When instructing the activation, provides a method and apparatus comprising the step of copying the PDCP Protocol Data Unit (PDU) from the PDCP entity to different Radio Link Control (RLC) objects to duplicate transmission of the same data to a plurality of base stations do.

Description

Method and controlling a data redundant transmission and Apparatuses

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

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

Current mobile communication systems such as Long Term Evolution (LTE), LTE-Advanced, 5G, etc. of the 3GPP series require a high-speed large-capacity communication system that can transmit and receive various data such as video and wireless data beyond voice-oriented services. have. In addition, after LTE-Advanced, a technology for a next generation wireless access network for accommodating data transmission and reception of more terminals and providing higher QoS has been developed. For example, development work on a tentative 5G network centered on 3GPP is in progress.

However, even if a next generation wireless access network technology is developed, a terminal and a base station using the existing network technology will exist together, and the terminal will provide a service using the existing network and the next generation network. In particular, in the case of dual connectivity technology in which a terminal maintains a 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 next generation wireless access network technology. It is necessary to provide a service.

However, at present, no specific method and terminal operation for providing dual connectivity by using a base station using an existing network technology and a base station using a next-generation network are not defined.

In addition, there is a need for redundant transmission of data through a plurality of radio paths for low latency, reliable data transmission and transmission, such as URLLC services.

In the above background, 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 is to propose a specific procedure and operation for redundant transmission of data by using the terminal and the base station when configuring a dual connection.

In order to solve the above problems, an embodiment of the present invention provides a method for configuring redundant transmission of data in a Packet Data Convegence Protocol (PDCP) entity from a base station in a method for duplex transmission of data by a terminal having dual connectivity. Receiving a radio resource control (RRC) message including information, configuring redundant transmission in the PDCP entity for one or more radio bearers, and instructions indicating whether to activate the redundant transmission operation of the configured PDCP entity from the base station; Steps for Receiving Information and Instruction When the information indicates activation, copying the PDCP Protocol Data Unit (PDU) from the PDCP entity and passing it to different Radio Link Control (RLC) entities to duplicately transmit the same data to multiple base stations. It provides a method comprising the steps.

In addition, according to an embodiment of the present invention, in which a base station having a dual connection with a terminal receives duplicate data, configuring redundant transmission in a Packet Data Convegence Protocol (PDCP) entity of a terminal for at least one radio bearer. Transmitting a radio resource control (RRC) message including configuration information for the terminal to the terminal; transmitting the indication information indicating whether to activate the duplicate transmission operation of the configured PDCP entity; and when the indication information indicates activation, It provides a method comprising the step of receiving the duplicated data transmitted from the PDCP entity of the terminal through the RLC entity of the base station and the RLC entity of another base station forming a dual connection to the terminal.

In addition, an embodiment is a radio resource control RRC including configuration information for configuring redundant transmission in a Packet Data Convegence Protocol (PDCP) entity from a base station in a terminal having a dual connection for redundant transmission of data ) A receiving unit for receiving a message and indicating indication information indicating whether or not to activate a duplicate transmission operation of a PDCP entity configured from a base station, and a controller and indication information constituting duplicate transmission in a PDCP entity for one or more radio bearers are activated. When indicating to provide a terminal device including a transmitter for copying the PDCP Protocol Data Unit (PDU) from the PDCP entity, and transmits the same data to a plurality of base stations by transferring to a different Radio Link Control (RLC) entity.

In addition, an embodiment is a base station for configuring a dual connection with the terminal and receiving data redundantly, for configuring redundant transmission in the Packet Data Convegence Protocol (PDCP) entity of the terminal for one or more radio bearers When the transmitter and the indication information for transmitting the RRC (Radio Resource Control) message including the configuration information to the terminal and transmitting the indication information indicating whether to activate the duplicate transmission operation of the configured PDCP entity indicates the activation, Provided is a base station apparatus including a receiving unit which duplicates data transmitted from a PDCP entity through an RLC entity of a base station and an RLC entity of another base station constituting a dual connection to the terminal.

The present disclosure provides an effect of quickly transmitting and receiving a large amount of data by configuring a dual connectivity by using a radio resource of a plurality of base stations.

In addition, the present disclosure is to support the redundant transmission of data while minimizing the waste of radio resources in a dual connectivity environment provides an effect of supporting a low latency high reliability data transmission and reception service.

1 is a diagram for exemplarily describing a secondary base station addition procedure according to the related art.
2 is a diagram illustrating an operation of a terminal according to an exemplary embodiment.
3 is a diagram for describing an operation of a base station according to an exemplary 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 illustrates a dual connectivity SRB configuration according to another embodiment.
7 is a diagram for describing a terminal configuration, according to an exemplary embodiment.
8 is a diagram illustrating a configuration of a base station according to an embodiment.

Hereinafter, some embodiments of the present invention will be described in detail through exemplary drawings. In adding reference numerals to the components of each drawing, it should be noted that the same reference numerals are assigned to the same components as much as possible even though they are shown in different drawings. In addition, in describing the present invention, when it is determined that the detailed description of the related well-known configuration or function may obscure the gist of the present invention, the detailed description thereof will be omitted.

In the present specification, the wireless communication system refers to a system for providing various communication services such as voice and packet data. The wireless communication system includes a user equipment (UE) and a base station (BS).

A user terminal is a comprehensive concept of a terminal in a wireless communication, and includes a user equipment (UE) in WCDMA, LTE, HSPA, and IMT-2020 (5G or New Radio), as well as a mobile station (MS) and a UT in GSM. It should be interpreted as a concept that includes a user terminal, a subscriber station (SS), and a wireless device.

A base station or cell generally refers to a station that communicates with a user terminal, and includes a Node-B, an evolved Node-B, an eNB, a gNode-B, and a Low Power Node. ), Sector, site, various types of antennas, base transceiver system (BTS), access point, access point (for example, transmission point, reception point, transmission / reception point), relay node ( It is meant to encompass various coverage areas such as a relay node, a mega cell, a macro cell, a micro cell, a pico cell, a femto cell, a remote radio head (RRH), a radio unit (RU), and a small cell.

Since the various cells listed above have a base station for controlling each cell, the base station may be interpreted in two meanings. 1) the device providing the mega cell, the macro cell, the micro cell, the pico cell, the femto cell, the small cell in relation to the wireless area, or 2) the wireless area itself. In 1) all devices that provide a given radio area are controlled by the same entity or interact with each other to cooperatively configure the radio area to the base station. According to the configuration of the wireless area, a point, a transmission point, a transmission point, a reception point, and the like become one embodiment of a base station. In 2), the base station may indicate the radio area itself that receives or transmits a signal from the viewpoint of the user terminal or the position of a neighboring base station.

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

In the present specification, the user terminal and the base station are used in a comprehensive sense as two entities (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 the terms or words specifically referred to. Do not.

Here, the uplink (Uplink, UL, or uplink) refers to a method for transmitting and receiving data to the base station by the user terminal, the downlink (Downlink, DL, or downlink) means to transmit and receive data to the user terminal by the base station It means the way.

The uplink transmission and the downlink transmission may use a time division duplex (TDD) scheme that is transmitted using different times, and use a frequency division duplex (FDD) scheme, a TDD scheme, and an FDD scheme, which are transmitted using different frequencies. Mixed mode may be used.

In addition, in a wireless communication system, a standard is configured by configuring uplink and downlink based on one carrier or a pair of carriers.

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), a physical downlink shared channel (PDSCH), a physical uplink shared channel (PUSCH), and the like. It is composed of the same data channel to transmit data.

Downlink (downlink) may mean a communication or communication path from the multiple transmission and reception points to the terminal, uplink (uplink) may mean a communication or communication path from the terminal to the multiple transmission and reception points. In this case, in the downlink, the transmitter may be part of multiple transmission / reception points, and the receiver may be part of the terminal. In addition, in uplink, a transmitter may be part of a terminal, and a receiver may be part of multiple transmission / reception points.

Hereinafter, a situation in which a signal is transmitted and received through a channel such as a PUCCH, a PUSCH, a PDCCH, and a PDSCH may be described in the form of 'sending and receiving a PUCCH, a PUSCH, a PDCCH, and a PDSCH.'

Meanwhile, high layer signaling described below includes RRC signaling for transmitting RRC information including an RRC parameter.

The base station performs downlink transmission to the terminals. The base station transmits downlink control information such as scheduling required for reception of a downlink data channel, which is a main physical channel for unicast transmission, and a physical downlink for transmitting scheduling grant information for transmission on an uplink data channel. The control channel can be transmitted. Hereinafter, the transmission and reception of signals through each channel will be described in the form of transmission and reception of the corresponding channel.

There is no limitation on the multiple access scheme applied in the wireless communication system. Time Division Multiple Access (TDMA), Frequency Division Multiple Access (FDMA), Code Division Multiple Access (CDMA), Orthogonal Frequency Division Multiple Access (OFDMA), Non-Orthogonal Multiple Access (NOMA), OFDM-TDMA, OFDM-FDMA, Various multiple access techniques such as OFDM-CDMA can be used. Here, the NOMA includes a sparse code multiple access (SCMA) and a low density spreading (LDS).

One embodiment of the present invention is for asynchronous radio communication evolving to LTE / LTE-Advanced, IMT-2020 via GSM, WCDMA, HSPA, and synchronous radio communication evolving to CDMA, CDMA-2000 and UMB. Can be applied.

In the present specification, a MTC terminal may mean a terminal supporting low cost (or low complexity) or a terminal supporting coverage enhancement. Alternatively, in the present specification, the MTC terminal may mean a terminal defined in a specific category for supporting low cost (or low complexity) and / or coverage enhancement.

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

In this specification, a NB-IoT (NarrowBand Internet of Things) terminal refers to a terminal that supports radio access for cellular IoT. The objectives of NB-IoT technology include improved Indoor coverage, support for large scale low speed terminals, low sensitivity, low cost terminal cost, low power consumption, and optimized network architecture.

As a typical usage scenario in New Radio (NR), which is recently discussed by 3GPP, enhanced Mobile BroadBand (eMBB), massive machine type communication (MMTC), and Ultra Reliable and Low Latency Communication (URLLC) are being raised.

In this specification, frequencies, frames, subframes, resources, resource blocks, regions, bands, subbands, control channels, data channels, synchronization signals, various reference signals, various signals, and various messages related to NR (New Radio). May be interpreted as meaning used in the past or present, or various meanings used in the future.

Dual connection in the present specification refers to a technology in which a terminal may transmit or receive data by configuring a wireless connection with a plurality of base stations, and will be described as a dual connectivity or a multi connectivity. However, 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 for the terminal to use the two base station radio resources at the same time. For multiple RX / TX terminals in the RRC Connected state, the dual connectivity operation is configured to use radio resources provided by two different schedulers located in connection with two base stations connected through non-ideal backhaul.

In dual connectivity, the terminal may provide a service through two base stations. For example, the terminal may perform communication using a master base station (MeNB) and a secondary base station (SeNB). The master base station may provide an RRC connection to the terminal, and may mean a base station that is a reference for handover, and the secondary base station may mean a base station that provides additional radio resources to the terminal.

In order to provide SeNB radio resources to the terminal, a SeNB addition procedure for setting the terminal context to the SeNB is used.

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

Each step will be described with reference to FIG. 1.

1. In step S100, the MeNB 110 requests the SeNB 120 to allocate radio resources to indicate characteristics for a specific 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, TNL address information corresponding to the UP option)). In addition, MeNB 110 uses the MCG configuration (including security algorithm for SCG bearer) and overall UE functions for UE function coordination in SCG-ConfigInfo as a basis for reconfiguration by SeNB 120 but does not include 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 capability coordination to be used as basis for the reconfiguration by the SeNB 120 , but does not include SCG configuration). The MeNB 110 can provide the latest measurement results for the SCG cell (s) requested to be added). 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 transport network resource according to the bearer option (If the RRM entity). in the SeNB (120) is able to admit the resource request, it allocates respective radio resources and, dependent on the bearer option, respective transport network resources). The SeNB 120 triggers random access to 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 the new radio resource of the SCG of SCG-Config to the MeNB 110 (The SeNB 120 provides the new radio resource of SCG in SCG-Config to the MeNB 110). For SCG bearers, together with S1 DL TNL address information for the respective E- along with S1 DL TNL address information for each E-RAB and security algorithm for the SCG bearer. 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 sends an RRCConnectionReconfiguration message to the UE including the new radio resource configuration of the SCG according to the SCG-Config (If the MeNB 110). endorses the new configuration, the MeNB (110) sends the RRCConnectionReconfiguration message to the UE including the new radio resource configuration of SCG according to the SCG-Config) .

4. In step S103, the UE 100 applies the new configuration and responds with a RRCConnectionReconfigurationComplete message (The UE applies the new configuration and replies with 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 is unable to comply with (part of) 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 respect to the PSCell of the SeNB 120 (The UE performs synchronization towards the PSCell of the SeNB 120). The order the UE sends the RRCConnectionReconfigurationComplete message and performs the Random Access procedure towards the SCG is not defined. The successful RA procedure towards the SCG is not required for a successful completion of the RRC Connection Reconfiguration procedure.

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

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

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

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

NR (New Radio)

3GPP is working on the next generation / 5G radio access technology (hereinafter referred to as NR for convenience of explanation). As the architecture for next-generation radio access technologies and the requirements for migration, the RAN architecture needs to support tight interworking between NR and LTE radio access technologies. In addition, dual connectivity technology may be used between NR base stations within the NR radio access technology. Dual connectivity in an NR environment can be defined as multi-connection. For example, multi-connectivity may be defined as an operation mode of a terminal for using a radio resource configured by an LTE base station and / or an NR base station (Multi-Connectivity: Mode of operation whereby a multiple Rx / Tx UE in the connected). mode is configured to utilise radio resources amongst E-UTRA and / or NR provided by multiple distinct schedulers connected via non-ideal backhaul).

NR radio access technology may also be deployed in the high frequency band (eg, high frequency above 6 GHz). In this case, fast SINR drops may occur due to link blockage and high transmission loss in the high frequency band. This may cause unnecessary delay or lower reliability when the NR base station wants to send a control plane RRC message or user plane data through an interface between the NR and the terminal. In particular, these problems make it difficult to provide services such as Ultra-Reliable Low latency Communications (URLLC). For example, in order to solve this problem, the control plane RRC message may be redundantly transmitted through one or more radio paths by using an RRC diversity technique. As another example to solve this problem, the user plane data can be redundantly transmitted through one or more radio paths based on multi-connection.

However, duplicate transmission has a problem of consuming additional radio resources. In other words, in a wireless access network, redundant transmission through two or more wireless paths may be considered as a method for providing reliable, low-latency service such as URLLC. There was a problem of consuming additional radio resources.

Disclosure of Invention The present disclosure devised to solve such a problem is to provide a redundant transmission processing method and apparatus capable of efficiently processing a service such as URLLC.

The embodiments described below may be applied to any wireless access network terminal as well as next generation mobile communication (5G mobile communication / NR) terminal.

For convenience of description, the base station may refer to an eNodeB, an LTE base station of LTE / E-UTRAN, and may be an NR node, a CU, a DU, or a 5G wireless network in which a central unit (CU) and a distributed unit (DU) are separated. GNodeB, NR base station in which CU and DU are implemented as one logical entity (CU, DU, or entity in which CU and DU is implemented as one logical entity, denoted as NR base station for convenience of description) All entities may be included in the scope of the present disclosure). Therefore, hereinafter, referred to as a base station, NR base station, LTE base station, etc. as needed, NR base station and LTE base station is classified according to the radio access technology. However, these terms are for convenience of explanation and division, and the terms are not limited.

In addition, in this specification, in order to describe a method for setting dual connectivity between an LTE base station and a NR base station using different radio access technologies, the LTE base station is described as a master base station as necessary and the NR base station is described as a secondary base station. It is described and described. However, the present disclosure may be applied to dual connectivity between LTE base stations, and may be equally applied to the case where the secondary base station is an LTE base station. Similarly, the present disclosure may be applied to the case where the NR base station is the master base station and the LTE base station is the secondary base station, and may also be applied to the dual connectivity between the LTE base stations.

Accordingly, the following description will be made of the LTE base station and the NR base station, but when it is necessary to specifically describe the operation according to the dual connectivity, the LTE base station is described as the master base station (MeNB), and the NR base station is referred to as the secondary base station (SeNB). List it. The name of each base station is for convenience of understanding, and an LTE base station may mean an eNB, and an NR base station may mean a gNB. That is, the present disclosure describes base stations by distinguishing base stations using different radio access technologies, and the terms are not limited thereto.

In dual connectivity for NR, the core network connection may consider the following scenario.

If the NR is integrated in 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 multiple 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 in the core network or the wireless network. Can be separated.

When LTE is integrated in the NR and connected via the 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 or wireless network. Can be separated.

When the NR is integrated in LTE and connected via 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 in the core network or wireless network. Can be separated.

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

LTE (Master Node)-NR (Secondary Node)

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

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

Dual / multi connectivity for NR may be considered as follows.

intra frequency dual / multi connectivity

-inter frequency dual / multi connectivity

 NR base station adds (modifies or releases or manages) NR cells (denoted as cell group or transmission point or transmission point group or transmission / reception point group or TRP or antenna or antenna group or beam, hereinafter referred to as cell), NR measurement, NR One or more control functions of measurement reporting, NR resource allocation, NR radio bearer addition / modification / release, NR radio resource configuration, and NR mobility control may be performed. The NR base station may instruct one or more control functions described above for the terminal through 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 may independently indicate a corresponding base station radio resource control configuration. As another example, the LTE RRC entity of the LTE base station may indicate a corresponding base station radio resource control configuration independently through the interface between the LTE and the terminal, and the NR RRC entity of the NR base station independently through the interface between the NR and the terminal. As another example, the LTE RRC entity of the LTE base station and the NR RRC entity of the NR base station may independently indicate a corresponding base station radio resource control configuration within a range not exceeding the terminal capability. As another example, the LTE RRC entity of the LTE base station and the NR RRC entity of the NR base station may indicate a corresponding base station radio resource control configuration through coordination. As another example, the LTE RRC entity of the LTE base station may instruct an LTE base station radio resource control configuration through an LTE radio link and an NR radio link. As another example, the NR RRC entity of the NR base station may instruct an LTE base station radio resource control configuration through the NR radio link and the LTE radio link.

Specific methods for the aforementioned radio resource control signaling transmission will be described later.

The terminal and the base station may transmit data redundantly using dual connectivity configured in the terminal in order to transmit the low latency high reliability data. That is, the terminal may duplicately transmit uplink data through two base stations, and the base station may also duplicately transmit downlink data using another base station constituting a dual connection to the terminal. However, when all data is repeatedly transmitted by using a plurality of radio paths, a limited radio resource is wasted. Accordingly, the present disclosure proposes an embodiment in which data is redundantly transmitted in order to provide low latency high reliability service while maximally preventing waste of limited radio resources.

For example, in dual connectivity based handover, the master base station (or secondary base station) may instruct to deliver the RRC signaling message through a plurality of paths through a signaling radio bearer configured between two base stations and the terminal.

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

As another example, the master base station (or the secondary base station) may instruct the user terminal configured with dual connectivity to transmit user plane data through one path through data on the data radio bearer configured between the two base stations and the terminal. In this case, a condition for switching a specific single path in the multiple paths or between the redundant transmission and the single path transmission may be indicated. For example, the condition may be an uplink data separation threshold. If redundant data transfers are not configured and enabled, and if data-redundant transfers are configured but not enabled, then the available PDCP data volume and RLC data volume associated with the two RLC entities are less than those conditions. Can be passed to an RLC entity in a single configured path.

Additional radio resources are consumed by redundantly transmitting RRC signaling messages or user plane data over multiple air interfaces. However, this can improve the reliability of control plane message transmission or user plane data transmission. In addition, if the secondary base station can directly transmit the RRC message to the terminal through the air interface, there may be an advantage that can quickly transmit data without delay of the backhaul interval between base stations.

As described above, the multipath redundant transmission method improves reliability but causes a consumption of radio resources due to complexity and redundant transmission. Hereinafter, the RRC message will be described based on duplicate transmission. This is for convenience of description only and duplicated transmission of user plane data may be provided in the same manner. Therefore, user plane data redundancy transmission is also included in the scope of the present embodiment. For example, this may be handled by the PDCP entity of the individual radio bearer that processes it for each control plane data or user plane data.

Meanwhile, the following description will focus on a case in which a terminal transmits uplink data, but the same procedure may be applied to a case in which a base station transmits downlink data. In addition, the dual connectivity in the present specification is described as a meaning that is applied to each, if 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.

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

2 is a diagram illustrating an operation of a terminal according to an exemplary embodiment.

2, a terminal according to an embodiment receives a radio resource control (RRC) message including configuration information for configuring redundant transmission in a Packet Data Convegence Protocol (PDCP) entity from a base station It may be performed (S210). The terminal may configure dual connectivity (dual connectivity) with a plurality of base stations. The plurality of base stations can be configured to use different radio access technologies. For example, the master base station may be a gNB using the aforementioned NR radio access technology, and the secondary base station may be an eNB using an LTE radio access technology. Alternatively, 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. Alternatively, both the master base station and the secondary base station may be gNBs using NR radio access technology. Dual connectivity may be configured in a terminal by a base station, and the terminal may transmit and receive data using radio resources configured with each of a plurality of base stations.

The terminal configured with the above-described dual connectivity may receive a Radio Resource Control (RRC) message including configuration information for configuring redundant transmission in a Packet Data Convegence Protocol (PDCP) entity from the base station. 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 duplicate data is received from a PDCP entity, a processing operation when a duplicate transmission function is activated or not, an operation of instructing configuration of two RLC entities associated with the PDCP entity, and The PDCP entity may include information for configuring the terminal so that at least one of the operations of transmitting data having the same PDCP SN through two paths may be performed.

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

Thereafter, the terminal may perform an operation of receiving indication information indicating whether to activate the duplicate transmission operation of the PDCP entity configured from the base station (S230). For example, the indication information may be received through a medium access control element (MAC CE). The indication information may include information indicating whether to change a duplicate transmission function of a PDCP entity to an activated state or an inactive state for a radio bearer configured to perform PDCP redundant transmission configured in a terminal. If the indication information indicates activation for a specific radio bearer to perform PDCP duplication, the MAC entity of the terminal may indicate activation of a duplicate transmission operation of the PDCP entity for the specific radio bearer to a higher layer. In other words, when the indication information received through the MAC CE indicates activation of the redundant transmission function, the MAC entity of the terminal may transmit the indication information to an upper layer (eg, an RRC layer or a PDCP layer) to indicate the indication.

When the indication information indicates activation, the UE may copy the PDCP protocol data units (PDUs) from the PDCP entity and transfer the same data to a plurality of base stations by transferring them to different Radio Link Control (RLC) entities. It may be (S240). For example, when a duplicate transmission function of a PDCP entity is configured (or changed) by the above-described indication information, for a specific radio bearer to perform PDCP duplication configured in a terminal, the PDCP entity for the specific radio bearer The UE may transmit the same data to the base station through a plurality of radio paths by copying data for transmission to the base station and transferring the data to a plurality of RLC entities connected to the PDCP entity for a specific radio bearer to perform PDCP duplication.

Meanwhile, the plurality of RLC entities may be configured in the terminal for each base station constituting the dual connectivity, and may be associated with one PDCP entity. The plurality of RLC entities may be associated with one corresponding PDCP entity through a radio bearer identifier or logical channel identifier. Therefore, when the PDCP entity delivers the same data to a plurality of associated RLC entities, each base station may receive the same data, and the master base station receives data through radio resources between the master base station and the terminal, and from the secondary base station Also, by receiving the same data, the data transmitted by the terminal can be repeatedly received. In this case, the PDCP entity of the base station may remove any one of the duplicately received data packets and transmit data to the upper layer. For example, the first received data packet may be delivered to a higher layer, and then the data packet having the same SN received may be removed.

If the PDCP entity indicates that the indication information for activating PDCP duplication for the radio bearer is inactive, and the duplex transmission operation of the PDCP entity is configured for the radio bearer, the PDCP entity is configured as one of a plurality of RLC entities. PDCP PDUs may be delivered. That is, if a duplicate transmission function in a PDCP entity is configured for a specific radio bearer for performing PDCP redundant transmission to a terminal, but the corresponding function is inactive, the PDCP entity may include one of a plurality of RLC entities configured for dual connectivity. Data can be delivered over a single path by passing data only to the RLC entity. This may be an RLC entity configured by default for the radio bearer. It may be used under various names, such as an RLC entity, a primary RLC entity, a default RLC entity, an initial configuration RLC entity, etc., for convenience of description, and the name is not limited.

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

In addition, the indication information may indicate whether the duplication transmission operation of the PDCP entity is activated to 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 terminal. In this case, the PDCP redundant transmission function is activated for a specific data radio bearer, but the PDCP redundant transmission function may be indicated with an inactive state. The indication information provided through the MAC CE to indicate whether the corresponding PDCP entity activates the redundant transmission operation for each of the one or more data radio bearers is for indicating an activation / deactivation state for each radio bearer corresponding to each radio bearer identifier. It may include bitmap information.

The base station described above may be a master base station or a secondary base station.

In this way, by determining whether or not redundant transmission for each data radio bearer, it is possible to minimize radio resource waste and data processing processing time loss due to redundant transmission. In addition, the redundant transmission function is configured in the terminal, but by dynamically controlling the activation through the MAC CE, it provides a dynamic management effect on the radio resources.

3 is a diagram for describing an operation of a base station according to an exemplary embodiment.

Referring to FIG. 3, a base station according to an embodiment includes radio resource control (RRC) including configuration information for configuring redundant transmission in a Packet Data Convegence Protocol (PDCP) entity of a terminal for one or more radio bearers. The transmitting of the message to the terminal may be performed (S310). The base station may configure a dual connection with the terminal along with other base stations. As described above, the base stations constituting the dual connection may be configured to use different radio access technologies. For example, the master base station may be a gNB using the aforementioned NR radio access technology, and the secondary base station may be an eNB using an LTE radio access technology. Alternatively, 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. Alternatively, both the master base station and the secondary base station may be gNBs using NR radio access technology. 3 may be a master base station or a secondary base station.

Meanwhile, the base station may transmit an RRC message including configuration information for configuring redundant transmission in the PDCP entity of the terminal for one or more radio bearers. 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 be a processing operation when duplicate data is received from a PDCP entity of a terminal, a processing operation when receiving a duplicate transmission function or not, and an operation of instructing configuration of two RLC entities associated with a PDCP entity. And information for configuring the terminal so that at least one of the operations of transmitting data having the same PDCP SN by the PDCP entity of the terminal through two paths may be performed.

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

Thereafter, the base station may perform the step of transmitting the indication information indicating whether to activate the duplicate transmission operation of the configured PDCP entity (S320). For example, the indication information may be transmitted through a medium access control element (MAC CE). The indication information may include information indicating whether to change the duplicate transmission function of the PDCP entity to an activated state or an inactive state for the radio bearer configured to perform PDCP redundant transmission configured in the terminal.

When the base station indicates the activation of the indication information through the MAC CE for the radio bearer to perform PDCP duplication transmission, the duplicated data transmitted from the PDCP entity for the corresponding radio bearer of the terminal is transmitted to the RLC entity of the base station and the terminal A duplicate reception may be performed through an RLC entity of another base station configuring a connection (S330). For example, when the indication information indicates activation, the MAC entity of the terminal may indicate activation of a redundant transmission operation of the PDCP entity to a higher layer. In other words, when the indication information received through the MAC CE indicates activation of the redundant transmission function, the MAC entity of the terminal may transmit the indication information to an upper layer (eg, an RRC layer or a PDCP layer) to indicate the indication.

When the indication information indicates the activation, the base station may duplicately receive data copied and transmitted from the PDCP entity of the terminal through the RLC entity of the base station and the RLC entity of another base station forming a dual connection to the terminal. In this case, the terminal copies the PDCP PDU (Protocol Data Unit) from the PDCP entity for the radio bearer to perform PDCP duplication of the terminal and delivers it to different RLC (Radio Link Control) entities configured for the radio bearer. Allows the base station to receive the same data over multiple RLC entities. The plurality of RLC entities configured in the terminal may be configured in the terminal for each base station constituting the dual connection and may be associated with one PDCP entity. Similarly, the PDCP entity of the base station may be associated with the RLC entity of the base station and may be associated with the RLC entity of another base station configuring a dual connection. The 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 terminal transmits the same data to a plurality of linked RLC entities, the PDCP entity of the base station may repeatedly receive the same data. In detail, the base station may receive data through a radio resource between the base station and the terminal, and may receive the same data from another base station through an interface between the base stations. In this case, the PDCP entity of the base station may remove any one of the duplicately received data packets and transmit data to the upper layer.

On the contrary, when the indication information indicates deactivation and the redundant transmission operation of the PDCP entity is configured in the terminal, the PDCP entity of the base station may receive data only through the RLC entity of the base station. For example, the first received data packet may be delivered to a higher layer, and then the data packet having the same SN received may be removed.

Meanwhile, the above-described redundant transmission function may be configured only for the data radio bearer (DRB). For example, the redundant transmission function in the PDCP entity may not be configured for the signaling radio bearer, but may be configured only for the data radio bearer.

In addition, the indication information may indicate whether the duplication transmission operation of the PDCP entity is activated to 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 terminal. In this case, the PDCP redundant transmission function is activated for a specific data radio bearer, but the PDCP redundant transmission function may be indicated with an inactive state. The indication information provided through the MAC CE to indicate whether the corresponding PDCP entity activates the redundant transmission operation for each of the one or more data radio bearers is for indicating an activation / deactivation state for each radio bearer corresponding to each radio bearer identifier. It may include bitmap information.

In the present specification, the PDCP entity, the RLC entity, and the MAC entity are described based on LTE terminology. However, 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 should be understood to mean an 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 delivers the data to a higher layer, performs data segmentation and reassembly functions, and performs functions such as reordering. .

As described above, according to the present embodiment, by determining whether to transmit duplicate data for each data radio bearer, it is possible to minimize radio resource waste and data processing processing time loss due to duplicate transmission. In addition, the redundant transmission function is configured in the terminal, but by dynamically controlling the activation through the MAC CE, it provides a dynamic management effect on the radio resources.

Hereinafter, various embodiments for performing the redundant transmission function in the aforementioned PDCP entity will be described by dividing the embodiments. The embodiments may be performed by the above-described terminal and base station, and as required, some or all of the steps in FIGS. 2 and 3 may be omitted, changed, replaced, or added according to the following embodiments.

First embodiment: A method for configuring redundant transmission / activation indication information through multiple paths.

Configuring redundant transmissions over multiple paths to operate at all times can waste radio resources excessively. As an example of a method for reducing radio resource consumption due to redundant transmission, the function (duplicate transmission function) is activated / deactivated or on / off (in the present specification, for convenience of description, denoted as enable / disable, enable / disable, can also be expressed in other terms such as on / off, activation / deactivation, etc.).

In the downlink RRC data transmission, the base station efficiently transmits the data by determining the RRC data transmission over the implementation (implementation).

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

The UE that receives the RRC message through the two paths may check and process it in PDCP or RRC. For example, it may first process the received data and discard the duplicate data. In another example, the function of detecting and discarding duplicate data may 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 duplicate data based on the PDCP SN. For another example, store a PDCP SN with a new PDCP SN. Then, if the PDCP SDU having the same PDCP SN is stored in the terminal (or PDCP entity), the terminal discards the PDCP SDU. The base station may indicate configuration information for the terminal to process such an operation.

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

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

For example, when instructing the terminal by setting the indication information indicating whether to activate the duplicate transmission of the RRC message to activate, when the terminal generates an uplink RRC message, the corresponding RRC message to the two transmission paths in the PDCP entity Can be sent via

For another example, when the base station instructs the terminal by setting the indication information indicating whether to activate the RRC message duplication transmission to the deactivation, when the terminal generates an uplink RRC message, the terminal transmits one RRC message in the PDCP entity Can be sent over the path.

For another example, when the base station instructs the terminal by setting information indicating whether to activate the RRC message duplication transmission to inactive, when the terminal generates an uplink RRC message, the terminal transmits the corresponding RRC message specified in the PDCP entity Can be sent through. The transmission path for this may be preconfigured in the terminal or indicated by the base station. This may be an RLC entity configured by default for the radio bearer. It may be used under various names, such as an RLC entity, a primary RLC entity, a default RLC entity, an initial configuration RLC entity, etc., for convenience of description, and the name is not limited.

As such, the indication information indicating whether the above-described redundant transmission is activated may be indicated to the terminal by higher layer signaling.

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

Redundant transmissions over multiple paths can always waste radio resources excessively.

In the downlink RRC data transmission, the base station efficiently transmits the data by determining the RRC data transmission over the implementation (implementation).

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

If redundant transmission is indicated through two paths, it may be undesirable to allow continuous transmission to continue during the corresponding RRC connection. Accordingly, the base station may indicate a timer for multi-path redundant transmission.

For example, the base station may indicate a duplicate transmission activation timer. When the terminal receives the RRC message including the duplicate transmission activation timer, the terminal starts the timer. When the uplink RRC message is generated while the corresponding timer is running, the UE may transmit the corresponding RRC message through two transmission paths in the PDCP entity. When the RRC message is generated after the timer expires, the terminal may transmit the PDCP entity through one transmission path. The transmission path for this may be preconfigured in the terminal or indicated by the base station. This may be an RLC entity configured by default for the radio bearer. As described above, the RLC entity, primary RLC entity, default RLC entity, initial configuration RLC entity, etc., which are configured for convenience of description, may be used under various names, and the names thereof are not limited.

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

For another example, the UE may generate a duplicate RRC message while a timer for deactivating duplicate transmission is generated, or transmit the corresponding RRC message through two transmission paths in the PDCP entity or duplicate transmission in the PDCP entity. When dealing with this, you can force the timer to restart. When the RRC message is generated after the corresponding timer expires, the terminal may transmit the PDCP entity through one transmission path.

Third Embodiment: Method of Instructing Activation / Deactivation Through Lower Layer Information.

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

For example, whether to activate the duplicate transmission function in the PDCP entity configured in the terminal may be indicated through the MAC CE. That is, if a duplicate transmission function in the PDCP entity is configured in the terminal, the base station may transmit the indication information indicating activation or deactivation of the corresponding function to the terminal. The indication information may include information for indicating whether to activate for each data radio bearer. When the indication information indicates the activation state, the terminal may transmit data repeatedly through a plurality of radio paths. To this end, the PDCP entity may deliver the same PDCP PDU to different RLC entities. The indication information provided through the MAC CE to indicate whether the corresponding PDCP entity activates the redundant transmission operation for each of the one or more data radio bearers is for indicating an activation / deactivation state for each radio bearer corresponding to each radio bearer identifier. It may include bitmap information.

For another example, the base station may indicate the indication information indicating whether to activate through the PDCCH.

For another example, when the terminal receives the indication information through the MAC CE or PDCCH, the terminal may transmit the indication information to the RRC or PDCP layer that processes the duplicate transmission.

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

Fourth Embodiment: Activating / Duplicate Redundancy Function Deactivate  How to dictate the conditions for.

The configuration information indicating the configuration of the RRC message redundant transmission to the terminal may include condition information for activating / deactivating the RRC data redundant transmission. Alternatively, the configuration information may include switching information for instructing the terminal to switch the data transmission path between two paths configured with dual connectivity, and the switching information may include condition information for switching the data transmission path. . For convenience of explanation, the following describes a condition for activating redundant transmission. The conditions for instructing to switch the data transmission path between two paths configured as dual connectivity may also be set identically or similarly. The condition may be included in the condition information described above.

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

For another example, the condition may be an uplink data separation threshold. If the redundant data transfer is not configured and enabled, and if the data-secure transfer is configured but not enabled, then the available PDCP data volume and RLC data volume associated with the two RLC objects are less than those conditions. Can be passed to an RLC entity in a single configured path.

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

As another example, the master base station and the secondary base station may be instructed to transmit data through a path providing a better radio quality.

As another example, when both the master base station and the secondary base station are smaller (or less than or equal to) a specific threshold, the RRC message may be transmitted through the two transmission paths in the PDCP entity.

If the condition for activating / deactivating RRC redundant transmission for this operation is satisfied, the physical layer may transmit it to the higher layer. For example, when the PDCP layer transmits through two transmission paths, the physical layer may indicate this to the PDCP entity. Alternatively, when the RRC layer transmits through two transmission paths, the physical layer may indicate this to the RRC.

If the PDCP entity indicates from the physical layer that the corresponding condition is satisfied, the PDCP entity may activate or deactivate redundant transmission.

To this end, the base station determines the threshold of radio quality associated with activation / deactivation, the threshold condition (e.g., the number of quality above the threshold, the number of quality below the threshold, the number of consecutive out of sync, the number of consecutive in sync). , Uplink data separation data amount threshold, etc.), a timer for checking the threshold condition, a period for checking the threshold condition, and an indication condition and filtering parameters to the upper layer may be indicated to the terminal. For example, you can use an RLM procedure for this. As another example, RRM measurements can be used for this. For another example, beam measurements can be used for this.

The downlink radio quality may be monitored by the terminal for a specific cell in the master cell group or all cells in the master cell group. This may be for triggering (determining / stopping / releasing / stopping) RRC redundant transmission or PDCP data (PDCP SDU or PDCP PDU) redundant transmission. Alternatively, the monitoring may be for indicating a state for an RRC redundant transmission or PDCP data redundant transmission to a higher layer.

Similarly, downlink radio quality may be monitored by the terminal for a specific cell in the secondary cell group or all cells in the secondary cell group. This may be for triggering (determining / stopping / releasing / stopping) RRC redundant transmission or PDCP data (PDCP SDU or PDCP PDU) redundant transmission. Alternatively, the monitoring may be for indicating a state for an RRC redundant transmission or PDCP data redundant transmission to a higher layer.

If the RLM is used, the base station may indicate a threshold for indicating the physical layer of the terminal to the upper layer in performing the RLM operation. The threshold value may be a separate threshold value separate from the threshold value for existing 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 an RRC message through two radio links by applying LTE-NR dual connectivity will be described in detail.

For convenience of explanation, hereinafter, a case of LTE (Master Node)-NR (Secondary Node) that can utilize well-established LTE coverage will be described. However, as described above, this is for convenience of description and the case of Master Node (NR)-Secondary Node (NR), Master Node (NR)-Secondary Node (LTE) is also included in the scope of the present embodiment.

The NR base station may control the NR radio resource of the terminal. Alternatively, the LTE base station may control the NR radio resources of the terminal.

 NR base station adds (modifies or releases or manages) NR cells (denoted as cell group or transmission point or transmission point group or transmission / reception point group or TRP or antenna or antenna group or beam, hereinafter referred to as cell), NR measurement, NR One or more control functions of measurement reporting, NR resource allocation, NR radio bearer addition / modification / release, NR radio resource configuration, and NR mobility control may be performed. The NR base station may instruct one or more control functions described above for the terminal through 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 may independently indicate a corresponding base station radio resource control configuration. As another example, the LTE RRC entity of the LTE base station may indicate a corresponding base station radio resource control configuration independently through the interface between the LTE and the terminal, and the NR RRC entity of the NR base station independently through the interface between the NR and the terminal. As another example, the LTE RRC entity of the LTE base station and the NR RRC entity of the NR base station may independently indicate a corresponding base station radio resource control configuration within a range not exceeding the terminal capability. As another example, the LTE RRC entity of the LTE base station and the NR RRC entity of the NR base station may indicate a corresponding base station radio resource control configuration through coordination. As another example, the LTE RRC entity of the LTE base station may instruct an LTE base station radio resource control configuration through an LTE radio link and an NR radio link. As another example, the NR RRC entity of the NR base station may instruct an LTE base station radio resource control configuration through 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. Sending through and corresponding terminal (or base station) should be able to distinguish and receive it. To this end, the following methods can be used individually or in combination.

For convenience of explanation, hereinafter, the NR base station (or terminal) transmits and receives between corresponding terminals (or NR base stations) (for example, when transmitting NR RRC messages in two paths). Alternatively, when a terminal transmits and receives between corresponding terminals (or LTE base stations) (for example, when transmitting an LTE RRC message through two paths), for example, an RRC message of an MeNB is transmitted between an MeNB and a terminal, In case of transmission to the terminal-to-terminal interface), the scope of this embodiment is also included.

1. Method of transmitting and receiving on two links in RRC layer.

The NR RRC entity of the NR base station (or terminal) generates an NR RRC message. The NR RRC message is transmitted through the NR-SRB1 to transfer the generated NR RRC message to the radio link between the NR base station and the terminal. Or submit to lower tier. The NR RRC entity of the NR base station (or terminal) may deliver an 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) forwards the NR RRC message including the NR RRC container / NR RRC IEs / NR RRC IEs to the LTE base station. An LTE base station (or an RRC entity of an LTE base station) may deliver an RRC message including an NR RRC container / NR RRC IEs / NR RRC IEs to a terminal (or an LTE RRC entity of the terminal) through an LTE SRB (LTE SRB1). The LTE RRC entity of the terminal transfers this to the NR RRC entity of the terminal.

The LTE RRC may transmit an RRC message including an NR RRC container / NR RRC IEs / NR RRC IEs as a transparent container in an RRC reconfiguration message to a terminal.

In this regard, as an example, the UE may include information for indicating to send the radio link path of one uplink RRC message to two links in the RRC message. As another example, information for instructing copying of one uplink RRC message to be transmitted to two links may be included in the RRC message and configured in the terminal. As another example, indication information for designating a radio link path of an uplink RRC message may be included in the RRC message and configured in the terminal. As another example, information for instructing copying one uplink RRC message to be transmitted to two radio links may be included in the RRC message and configured in the terminal.

2. How to send and receive over two links at the PDCP layer.

The NR RRC entity of the NR base station (or terminal) generates an NR RRC message. The NR RRC message is transmitted through the NR-splitSRB1 to deliver the generated NR RRC message to the radio link between the NR base station and the terminal and the radio link between the LTE base station and the terminal. Or submit to lower tier. 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. The PDCP PDU including one NR RRC message is delivered to the LTE RLC entity. The PDCP PDU containing another NR RRC message is delivered to the NR L2 entity.

Meanwhile, as an example, the terminal may include information for instructing to enable a function for transmitting PDCP data including an uplink RRC message to two radio links in an uplink L2 entity (PDCP).

Another example is to instruct a PDCP (upper L2 entity) to copy and / or submit PDCP SDUs / PDUs to each associated lower layer entity to send PDCP data including uplink RRC messages to the two radio links. The information may be included in the RRC message and configured in the terminal.

As another example, indication information for designating a radio link path of an uplink RRC message may be included in the RRC message and configured in the terminal.

The same copied PDCP data in the peered PDCP entity may be discarded. The base station may be configured by instructing the terminal instructing the terminal to discard the PDCP PDU / SDU received the same RRC message and duplicately received.

In another example, the NR RRC entity of the NR base station (or terminal) generates an NR RRC message. And copy it. The NR RRC entity delivers the generated NR RRC message through the NR-splitSRB1 to deliver the generated NR RRC message to the radio link between the NR base station and the terminal and the radio link between the LTE base station and the terminal. Or submit to lower tier. 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 differently and the path (LTE base station radio link and NR base station radio link) of the PDCP SDU including the next received RRC message.

Herein, the case where the NR base station is the master base station has been described as an example, but the same may 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 copy and discard PDCP data.

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

For reliable RRC message transmission (or for any reason), the transmitting end sends RRC messages over two radio links, and for the same RRC message received over two radio links, the receiving end distinguishes duplicate RRC messages. Duplicate RRC messages can be discarded / dropped / removed / discarded. The base station may configure information for indicating this to the terminal.

In the transmitting end (base station or terminal), the RRC message may include identification information to distinguish the same RRC message. For example, identification information for distinguishing the RRC message is incremented each time a new RRC message is generated. And when you reach the largest value, you can cycle back to the smallest value. For example, if you have a value from 0 to 3 (or 1 to 4), the first RRC message starts at 0 (or 1) and increments by one. When 3 (or 4) is reached, the next RRC message is again 0 (or 1). Is cycled to

When the receiving end (corresponding terminal or base station) receives the RRC message including the same RRC message identification information as the previously received RRC message, it may discard / drop / remove / discard the corresponding RRC message.

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

The base station may configure the terminal with information for indicating that the RRC message includes the RRC message identification information. If the corresponding information is configured, the terminal may recognize that the RRC message identification information is included.

4. How to use Transaction identifier.

For reliable RRC message transmission (or for any reason), the transmitting end sends RRC messages over two radio links, and for the same RRC message received over two radio links, the receiving end distinguishes duplicate RRC messages. Duplicate RRC messages can be discarded / dropped / removed / discarded. The base station may configure information for indicating this to the terminal.

By using the transaction identifier included in the RRC message, duplicate RRC messages can be distinguished and discarded, dropped, removed, or discarded.

The terminal, if included, sets the same RRC transaction identifier as the RRC transaction identifier included in the message received from the base station triggering the response message in the response message.

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

When the receiving end (corresponding terminal or base station) receives an RRC message including the same Transaction identifier as the previously received RRC message, it may discard / drop / remove / discard the corresponding RRC message.

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

Meanwhile, an embodiment of configuring dual connectivity and transmitting RRC signaling will be described below. That is, specific methods for the aforementioned radio resource control signaling transmission to the terminal will be described. For the RRC signaling transmission, the following methods may be used independently or in combination. For the convenience of description, the signaling radio bearer will be described, but the data radio bearer may be configured in the same or similar manner.

1.Use LTE base station SRB (Signaling wireless bearing)

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

This method has an advantage in that the RRC configuration information of the NR base station can be delivered to the terminal with little change in 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 should receive a confirmation message for the NR RRC configuration of the terminal from the LTE base station. This is also a factor that causes delay.

As an example to improve this, when the UE transmits an RRC message including an NR RRC container / NR RRC IEs / NR RRC IEs to the UE (or an RRC entity of the UE), the RRC entity of the UE directly RRC to the NR base station. Instruct to send a reconfiguration confirmation 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 delivers / submits it to the NR RRC entity. The NR RRC entity applies the new configuration. The NR RRC entity responds to the RRC reconfiguration acknowledgment message via the interface between the terminal and the NR base station.

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

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

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

For another example, if the terminal receives an RRC message (or an RRC message including information indicating an initial NR configuration setup) including the NR RRC container / NR RRC IEs / NR RRC IEs, the terminal NR The RRC entity may enable / activate the NR additional configuration (or the terminal may set / create the NR RRC entity).

For another example, if the terminal receives an RRC message including information indicating NR radio resource release, the terminal may allow the NR RRC entity to disable / deactivate / deactivate.

As another example, an RRC reconfiguration message (or an RRC message including NR RRC container / NR RRC IEs / NR RRC IEs) may instruct the terminal to transmit an RRC confirmation message through an interface between the terminal and the NR base station in an NR RRC entity. It may include information for.

For another example, the RRC reconfiguration message (or RRC message including NR RRC container / NR RRC IEs / NR RRC IEs) is an NR for the terminal to transmit the RRC confirmation message through the interface between the terminal and the NR base station in the NR RRC entity It may include the base station SRB configuration information.

2. SRB configuration through NR base station

For example, the NR base station may transmit an NR RRC message to the terminal through an interface between the NR base station and the terminal. To this end, when configuring the LTE-NR dual connectivity (or when configuring the NR additional radio resources), the NR base station may configure an SRB (eg, SRB1) between the terminal and the NR base station. This means that the NR base station determines the addition of an SRB (eg, SRB1) between the terminal and the NR base station for the corresponding terminal and generates configuration information therefor. For reference, in the conventional LTE, SRB1 was performed in an RRC connection configuration, but SRB1 between the NR base station and the terminal (hereinafter, for convenience of description, a signaling radio bearer configured to transmit data through an interface between the NR base station and the terminal is referred to as NR-SRB1). The configuration may be configured through an RRC reconfiguration message constituting LTE-NR dual connectivity (constituting NR additional radio resources).

Once security is activated, all RRC messages on the NR-SRB1 (or SRB1 / SRB2) must be integrity protected and ciphered by the PDCP (or L2 entity on the 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 (parent) L2 entity on the NR).

For this purpose, for NR-SRB1, security must always be activated from the start. The LTE base station should not set up the bearer before activating security for this bearer. The LTE base station should not request the addition of an NR base station before activating security. The NR base station may set the NR-SRB1 according to the request for adding the NR base station from the LTE base station.

For example, when requesting addition of an NR base station, the LTE base station forwards (or computes and delivers) the NR base station key (eg, NR-K _eNB ) to the NR base station. The NR base station selects an integrity protection algorithm and a ciphering algorithm. Then, the LTE base station transmits the selected integrity protection algorithm and the ciphering algorithm (or the identification information on the integrity protection algorithm and the ciphering algorithm) to service the NR-SRB1 for the terminal to the terminal. The LTE base station (or NR base station) instructs the terminal to the counter (SCG Counter or NR Counter) for calculating the key value associated with the NR-SRB1. The terminal calculates the NR base station key. The terminal calculates a key value associated with NR-SRB1 (NR-K _RRCint , NR-K _RRCenc ). The terminal is configured such that the lower layer (PDCP or L2 entity on NR) applies an integrity protection algorithm, a _ciphering 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 composed of the RLC entity of the LTE 400, one or two entities that redistribute the LTE MAC entity function. In FIG. 4, an example in which an LTE-RRC object and an NR-RRC object are configured in the terminal 410, respectively, is also included in the scope of the present invention.

If a single RRC entity / layer is configured in the terminal 410, data may 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 two RRC entities are configured in the terminal 410, data may be transmitted through the NR-SRB1 for the RRC message received from the NR base station 450 and for the corresponding response RRC message. The NR base station 450 may preferentially process the NR-SRB1 over the DRB. For example, a specific logical channel identification value may be designated for NR-SRB1. For another example, a logical channel identification value (for example, 1) such as SRB1 may be specified for NR-splitSRB1. As another example, an SRB-identity value (eg, 1), such as SRB1, may be specified for NR-SRB1. As another example, logical channel configuration values (e.g., priority (1 or 2), prioritisedBitRate (infinite)) such as / similar to SRB1 may be specified for NR-SRB1. For another example, the same logical channel identification information as SRB1 may be included, but the terminal may include information for identifying that the terminal is SCG SRB1.

In another example, it may include logical channel identification information different from SRB1, but may include the same logical channel configuration information as SRB1.

NR base station 450, NR cell / cell group / transmission point / transmission point group / transmission and reception point / transmission and reception point group / TRP / antenna / antenna group / beam addition / modification / release / management, NR measurement, NR measurement reporting, NR An NR RRC message including one or more control information of resource allocation, NR radio bearer addition / modification / release, NR radio resource configuration, and NR mobility control may be sent to the terminal 410. For the downlink RRC message, the NR base station (or the RRC entity of the NR base station) 450 may deliver the NR RRC message including the NR RRC container / NR RRC IEs / NR RRC IEs to the terminal 410 through the NR-SRB1. .

When the terminal receives an NR RRC message (eg, an RRC Connection Reconfiguration message) through the NR-SRB1, the terminal may apply a 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) How to apply a new configuration through one RRC entity in the terminal

The terminal may configure the NR radio resource through the RRC entity.

In the conventional LTE dual connectivity, when the MeNB sends an RRC message including the new radio resource configuration of the SCG to the terminal, the terminal performs the reconfiguration failure procedure if the terminal cannot comply with the (partial) configuration included in the RRC connection reconfiguration message. do.

The reconfiguration failure procedure in LTE is performed as follows.

If the terminal cannot comply with the (partial) configuration included in the RRC connection reconfiguration message, the terminal continues to use the configuration used before receiving the RRC connection reconfiguration message. If the security is not activated, the operation of leaving RRC_CONNECTED is performed with the cause of release as other. If not, initiate the connection re-establishment procedure.

As described above, the reconfiguration failure in LTE has caused service interruption by switching the terminal to idle mode or performing an RRC connection reconfiguration procedure.

On the other hand, the NR, due to its nature, may fail due to various reasons in the NR radio resource configuration process. Therefore, when a failure occurs in the NR radio resource configuration process for any reason, it may be inefficient to switch the terminal to the idle mode or perform an RRC connection resetting procedure.

As an example to improve this, if the UE fails in the NR configuration included in the NR RRC message (or for some reason cannot comply with the NR configuration included in the NR RRC message), the UE does not trigger the reconfiguration failure procedure. You can do that. That is, it is possible to prevent the NR RRC configuration failure from triggering the LTE RRC configuration failure. For example, if NR RRC configuration fails, the UE sends an RRC message (for example, an SCG failure information message, a UE assistance message, or a newly defined NR failure information / NR status message) including the cause of the NR RRC configuration failure to the NR base station. Can transmit In another example, if NR RRC configuration fails, the UE sends an RRC message (for example, an SCG failure information message, a UE assistance message, or a newly defined NR failure information / NR status message) including the cause of the NR RRC configuration failure to the LTE base station. Can transmit That is, the terminal may transmit the failure information to the master base station when the radio resource configuration of the secondary base station fails using the RRC message received through the SRB of the secondary base station.

This will be described in more detail below.

The received RRC message includes configuration information for configuring an NR radio resource (eg, NR cell configuration information, NR bearer configuration information, control information for NR random access, NR measurement configuration information, NR mobility control, and NR radio resource only). One or more of the configuration information). Hereinafter, for convenience of description, configuration information for additionally modifying an NR base station in dual connectivity or information for reconfiguring NR radio resources through the secondary base station SRB may include secondary base station radio resource configuration information, NR radio resource configuration information, and NR configuration information. Or as configuration information.

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

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

In each of the above examples, if the terminal cannot follow the NR configuration, the terminal continues to use the (NR) configuration used before receiving the RRC connection reconfiguration message (before receiving the NR configuration information).

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

Or, if the terminal RRC cannot follow the NR configuration, the RRC transmits an RRC message including the cause of the NR RRC configuration failure to the LTE base station. The LTE base station forwards this to the NR base station.

Alternatively, if the terminal RRC cannot follow 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 an interface between the terminal and the NR base station.

2-2) How to apply a new configuration through two RRC entities in the terminal

As mentioned above, the NR can include LTE and other evolutionary features independently. In order to implement this effectively in the UE, LTE RRC and NR RRC may be configured.

In the conventional LTE dual connectivity, when the MeNB sends an RRC message including the new radio resource configuration of the SCG to the terminal, the terminal performs the reconfiguration failure procedure if the terminal cannot comply with the (partial) configuration included in the RRC connection reconfiguration message. do. The reconfiguration failure procedure in LTE is performed as follows.

If the terminal cannot follow the (partial) configuration included in the RRC connection reconfiguration message, the terminal continues to use the configuration used before receiving the RRC connection reconfiguration message. If security is not activated, RRC_CONNECTED is performed with the cause of release as other. If not, initiate the connection re-establishment procedure.

As described above, the reconfiguration failure in LTE has caused service interruption by switching the terminal to idle mode or performing an RRC connection reconfiguration procedure.

On the other hand, NR, due to its nature, may have various reasons for failure in the NR addition process. Therefore, when a failure occurs in the NR addition process for any reason, it may be inefficient to switch the terminal to the idle mode or perform the RRC connection resetting procedure.

As an example to improve this, the UE may not trigger a reconfiguration failure procedure if the NR configuration included in the NR RRC message fails (or if the NR configuration included in the NR RRC message for some reason cannot be followed). . It is possible to ensure that the NR RRC configuration failure does not trigger the LTE RRC configuration failure. If the NR RRC configuration fails, the UE sends an RRC message (for example, an SCG failure information message, a UE assistance message, a newly defined NR failure information / NR status message) including the cause of the NR RRC configuration failure to the NR base station (or LTE base station). Can be sent. Or, if the terminal RRC cannot follow the NR configuration, the RRC transmits an RRC message including the cause of the NR RRC configuration failure to the LTE base station. The LTE base station forwards this to the NR base station.

This will be described in more detail below.

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

Or, if the terminal NR RRC cannot follow the NR configuration, the terminal continues to use the (NR) configuration used before the RRC connection reconfiguration message is received (before the NR RRC receives the NR configuration information).

Or if the terminal (NR RRC) can not follow the NR configuration, suspend / interrupt / stop / release the NR radio resource use. The NR radio resource may include at least one of a secondary cell group DRB (secondary cell group DRB), a secondary cell group SRB, a secondary cell group part of a split DRB, and a secondary cell group part of a split SRB.

Or, if the terminal (NR RRC) can not follow the NR configuration, release the NR radio resources

Or, if the terminal (NR RRC) can not follow the NR configuration, the NR RRC indicates the NR reconfiguration failure to the LTE RRC. The LTE RRC sends an RRC message including the cause of the NR RRC configuration failure to the LTE base station. The LTE base station forwards this to the NR base station.

Or, if the terminal (NR RRC) can not follow the NR configuration, the NR RRC directly transmits the 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.

Hereinafter, another example of NR radio link failure will be described.

When detecting a radio link problem (failure) on the NR physical layer, the terminal may indicate 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 failure for the NR physical layer failure.

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

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

NR base station NR cell / cell group / transmission point / transmission point group / transmission and reception point / transmission and reception point group / TRP / antenna / antenna group / beam addition / modification / release / management, NR measurement, NR measurement reporting, NR resource allocation, An NR RRC message including one or more control information of NR radio bearer addition / modification / release, NR radio resource configuration, and NR mobility control may be directly sent to the terminal.

However, NR can also be built in the high frequency band (eg, high frequency above 6 GHz). In this case, fast SINR drops may occur due to high frequency band link blockage and high transmission loss. And it can cause problems when sending NR RRC. To compensate for this problem, the NR RRC message can be sent using both the interface between the NR base station and the terminal and the interface between the LTE base station and the terminal.

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

Referring to FIG. 5, for example, when configuring the LTE-NR dual connectivity to the terminal 510 (or configuring the NR additional radio resource), the NR base station 550 may be configured as the terminal 510 by the LTE base station ( It is possible to configure an SRB (eg, SRB1 type) that can use both 500 and NR base station 550. SRB that can use both LTE base station 500 and NR base station 550 (For convenience of description, a signaling radio bearer configured so that the NR base station can use both the LTE base station and the NR base station will be referred to as NR-splitSRB1.) The configuration may be configured via an RRC reconfiguration message that (re) configures LTE-NR dual connectivity (which constitutes an NR additional radio resource).

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

For this purpose, for NR-splitSRB1, security must always be activated from the start. The 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 security. Alternatively, the NR base station 550 should not request the LTE base station 500 to add the NR-splitSRB1 before activating security. The NR base station 550 may set NR-splitSRB1 according to a request for adding an NR base station of the LTE base station 500. Alternatively, the NR base station 550 may set NR-splitSRB1 as needed.

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

For another example, the NR base station 550 may indicate the information for configuring the NR-splitSRB1 to the LTE base station 500. As described above, the LTE base station 500 may not understand the NR RRC container / NR RRC IEs of the NR base station 550. Accordingly, the NR base station 550 may include information for instructing the LTE base station 500 to configure NR-splitSRB1 in a signaling message on an interface between the NR base station 550 and the LTE base station 500. When the LTE base station 500 receives the information for instructing to configure the NR-splitSRB1, the LTE base station 500 may instruct the terminal 510 to configure the information for configuring the NR-splitSRB1. The LTE base station 500 may instruct the terminal 510 to preferentially process the NR-splitSRB1 over the DRB. For example, a specific logical channel identification value may be designated for NR-splitSRB1. The terminal 510 may preferentially process the logical channel designated as NR-splitSRB1 over the DRB. For another example, a logical channel identification value (1) such as SRB1 may be specified for NR-splitSRB1. As another example, information for processing NR-splitSRB1 at the same priority as SRB1 may be indicated. For another example, information for indicating that the signaling bearer may be indicated for NR-splitSRB1. For example, logical channel identification information different from SRB1 is specified for NR-splitSRB1, but information for processing at the same priority as SRB1 may be indicated. For example, it may include the same logical channel configuration information as SRB1. For another example, an SRB-identity value (eg, 1), such as SRB1, may be specified for NR-splitSRB1. For another example, a logical channel configuration value (eg priority (1 or 2), prioritisedBitRate (infinite)) such as / similar to SRB1 may be specified for NR-splitSRB1. For example, the same logical channel identification information as SRB1 may be included, but the terminal may include information for identifying an entity for NR-split SRB1.

In another example, it may include logical channel identification information different from SRB1, 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 other wireless communication features than LTE, and the LTE base station may not understand the RRC message generated by the NR base station.

NR base station NR cell / cell group / transmission point / transmission point group / transmission and reception point / transmission and reception point group / TRP / antenna / antenna group / beam addition / modification / release / management, NR measurement, NR measurement reporting, NR resource allocation, An NR RRC message including one or more control information of NR radio bearer addition / modification / release, NR radio resource configuration, and NR mobility control may be directly sent to the terminal.

However, NR can also be built in the high frequency band (eg, high frequency above 6 GHz). In this case, high frequency band link blockage and high transmission loss can cause fast SINR drops and cause problems when sending NR RRC. To compensate for this problem, the NR RRC message can be sent using both the interface between the NR base station and the terminal and the interface between the LTE base station and the terminal.

On the other hand, some uplink or downlink RRC message may be preferably delivered first through the LTE base station for reliability.

6 illustrates a dual connectivity SRB configuration according to another embodiment.

Referring to FIG. 6, for example, when configuring the LTE-NR dual connectivity in the terminal 610 (when configuring an NR additional radio resource), the LTE base station 600 is a terminal 610 is an LTE base station 600 It is possible to configure an SRB (e.g. of type SRB1) that can use both the and NR base station 650. SRB that can use both LTE base station 600 and NR base station 650 (For convenience of description, a signaling radio bearer configured so that the LTE base station can use both the LTE base station and the NR base station will be referred to as LTE-splitSRB1. The configuration may be configured via an RRC reconfiguration message that (re) configures LTE-NR dual connectivity (which constitutes NR additional radio resources).

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

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

For example, when requesting addition of an NR base station, the LTE base station 600 transmits information to the NR base station 650 to indicate configuration of the LTE-splitSRB1. The NR base station 650 transfers information (for example, one or more information of logaicalchannelconfig, logicalchannelIdentity, and rlcconfig) for configuring the NR part of the LTE-splitSRB1 to the terminal 610 through the LTE base station 600. For another example, the NR base station 650 may instruct the LTE base station 600 information for confirming the configuration of the LTE-splitSRB1. As described above, the LTE base station 600 may not understand the NR RRC container / NR RRC IEs of the NR base station 650. Accordingly, 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-splitSRB1 configuration to the LTE base station 600. When the LTE base station 600 receives information for instructing to configure the LTE-splitSRB1, the LTE base station 600 may instruct the terminal 610 to configure information for configuring the LTE part of the LTE-splitSRB1. The LTE base station 600 may allow the LTE-splitSRB1 to be processed in preference to the DRB. For example, a specific logical channel identification value may be designated for LTE-splitSRB1. The terminal 610 may be configured to process the logical channel designated as LTE-splitSRB1 in preference to the DRB. For another example, a logical channel identification value (1) such as SRB1 may be specified for NR-splitSRB1 (or may be configured as SRB1 or SRB2).

The NR base station 650 may allow the LTE-splitSRB1 to take priority over the DRB. For example, a specific logical channel identification value may be designated for LTE-splitSRB1. The terminal 610 may be configured to process the logical channel designated as LTE-splitSRB1 in preference to the DRB. As another example, a logical channel identity value (1), such as SRB1, may be specified for LTE-splitSRB1 (or may be configured as SRB1 or SRB2). For example, SRB1 may be configured for LTE-splitSRB1. Information for processing at the same priority may be indicated. For another example, information for indicating that the signaling bearer may be indicated for LTE-splitSRB1. For another example, an SRB-identity value (eg, 1), such as SRB1, may be specified for LTE-splitSRB1. For another example, a logical channel configuration value (eg priority (1 or 2), prioritisedBitRate (infinite)), such as SRB1, may be specified for LTE-splitSRB1. For another example, since the LTE-splitSRB1 may be treated like the SRB1, a separate configuration may not be performed. For example, the same logical channel identification information as SRB1 may be included, but the terminal may include information for identifying an entity for LTE-split SRB1.

In another example, it may include logical channel identification information different from SRB1, but may include the same logical channel configuration information as SRB1.

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

On the other hand, when the terminal receives different RRC message will be described in detail for the processing method.

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

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

As an example, if the terminal is set to release the NR base station radio resources in the RRC message received from the LTE base station, the terminal releases the entire (NR) base station radio resources except the DRB configuration. If the current terminal configuration includes one or more split or SCG DRBs, and if the received RRC reconfiguration message includes radio resource configuration only information including the DRB information (drb-ToAddModList) to be further modified, according to the DRB information to be further modified. Reconfigure split or SCG DRB.

As another example, if the terminal is set to release the NR base station radio resources in the RRC message received from the LTE base station, the terminal releases the entire (NR) base station radio resources.

When the LTE base station directs the RRC message to the terminal indicating the NR base station radio resource configuration (which affects the NR base station radio resource configuration / affects the NR base station radio resource configuration), the NR base station indicates the NR base station radio resource configuration The RRC message may be indicated to the terminal.

For example, an NR base station may have at least one of NR cell addition (modification or release or management), NR measurement, NR measurement reporting, NR resource allocation, NR radio bearer addition / modification / release, NR radio resource configuration and NR mobility control. An RRC message indicating resource configuration may be indicated to the terminal.

For example, the UE may receive another RRC message before receiving one RRC message and completing application thereof.

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

If the terminal configures the NR base station radio resource according to the RRC message received from the NR base station, the RRC message including information indicating that the terminal releases the NR base station radio resource (NR-configuration) from the LTE base station If receiving the terminal, the terminal may perform one or more of the following operations.

The terminal may perform radio resource release of the NR base station.

When the NR base station radio resource release is received from the LTE base station, the terminal stops the operation of the RRC message being performed before receiving / stopping / canceling / dropping / pausing / override / running the RRC message. Return to NR base station radio resource release.

The UE is configured to use the NR base station radio resource release from the LTE base station before receiving / stopping / canceling / holding / dropping / pausing / override / running RRC message. An RRC message including information indicating that a return has occurred may be transmitted to the NR base station.

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

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

If the current UE configuration includes one or more split or SCG DRBs, and if the received RRC reconfiguration message includes radio resource configuration only information including DRB information (drb-ToAddModList) to be modified further, the DRB information to be modified Reconfigure split or SCG DRB accordingly.

The base station (LTE base station or NR base station) may be configured by instructing the terminal with information for instructing the above-described operation.

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

If the terminal configures the NR base station radio resource according to the RRC message received from the LTE base station, the RRC message including information indicating that the terminal releases the NR base station radio resource (NR-configuration) from the NR base station If receiving the terminal, the terminal may perform one or more of the following operations.

The terminal may perform radio resource release of the NR base station.

When the NR base station radio resource release is received from the NR base station, the terminal stops the operation of the RRC message being performed before receiving / receiving / stopping / pausing / override / running the RRC message. Return to NR base station radio resource release.

-UE is configured to use the NR base station radio resource release is received from the NR base station before receiving the stop / stop / cancel / hold / drop / pause / override / performing RRC message in progress An RRC message including information indicating that reversion has occurred may be transmitted to the LTE base station.

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

If the NR base station radio resource is set to release in the RRC message received from the NR base station, the terminal releases the entire NR base station radio resource except for the DRB configuration.

If the current UE configuration includes one or more split or SCG DRBs, and if the received RRC reconfiguration message includes radio resource configuration only information including DRB information (drb-ToAddModList) to be modified further, the DRB information to be modified Reconfigure split or SCG DRB accordingly.

The base station (LTE base station or NR base station) may be configured by instructing the terminal with information for instructing the above-described operation.

3. When different RRC messages are received except for NR radio resource release

If the terminal configures the NR base station radio resources according to the RRC message received from the LTE base station, the RRC including information indicating the terminal to add / modify / configure the NR base station radio resources (NR-configuration) from the NR base station If the message is received, the terminal may perform one or more of the following operations. (Or if the terminal configures the NR base station radio resources according to the RRC message received from the NR base station, the terminal includes information indicating the NR base station addition / modification / configuration from the LTE base station If the RRC message is received, the UE may perform one or more of the following operations.)

-The NR base station radio resources may be sequentially configured in the order of the RRC message received by the terminal. Accordingly, the UE may first receive an RRC message received and complete an operation for configuring the RRC message, and then configure an NR base station radio resource according to the received RRC message.

It is possible to first process the RRC message received from the master base station (eg LTE base station). The UE indicates to the secondary base station (e.g., NR base station) that the reversion to the configuration used before the RRC configuration instruction receives an interrupt / stop / cancel / drop / drop / override / running RRC message has occurred. The RRC message including the may transmit to the secondary base station (for example, the NR base station).

May first process the RRC message received from the NR base station. The UE sends an RRC message including information indicating that an RRC configuration indication by the LTE base station is returned to the configuration used before receiving an interruption / stop / cancel / drop / override / running RRC message. It can transmit to the NR base station.

The base station (LTE base station or NR base station) may be configured by instructing the terminal with information for instructing the above-described operation.

As described herein, the present disclosure provides an effect of minimizing unnecessary waste of radio resources and data processing time when the terminal performs data redundant transmission through a plurality of different radio paths. In addition, the present disclosure has an effect that the terminal can be processed to efficiently perform redundant transmission through two different radio paths. It is possible to effectively handle the radio resource control signaling of the NR base station for the LTE-NR dual connectivity operation that supports tight interworking between LTE and NR. In addition, there is an effect that the base station can process the RRC message using two different radio access links.

Hereinafter, a terminal and a base station apparatus capable of performing some 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 describing a terminal configuration, according to an exemplary embodiment.

Referring to FIG. 7, a terminal 700 having a dual connection for redundant transmission of data includes a radio resource including configuration information for configuring redundant transmission in a Packet Data Convegence Protocol (PDCP) entity from a base station. A control unit configured to receive a message and receive indication information indicating whether activation of a duplicate transmission operation of a PDCP entity configured from a base station is performed, and a control unit configured to configure duplicate transmission in a PDCP entity for at least one radio bearer ( 710) and when the indication information indicates the activation, the transmitter 720 for copying the PDCP Protocol Data Unit (PDU) from the PDCP entity and forwarded to different Radio Link Control (RLC) entities to duplicately transmit the same data to a plurality of base stations. ) May be included.

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

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

On the other hand, 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 may include processing operation when duplicate data is received from a PDCP entity, processing operation when receiving a duplicate transmission function, and data in which the PDCP entity has the same PDCP SN through two paths. It may include information for configuring the terminal so that at least one of the transmitting operations can be performed.

In addition, the receiver 730 may receive indication information through a medium access control control element (MAC CE). The indication information may include information indicating whether to change the redundant transmission function of the PDCP entity configured in the terminal to an activated state or an inactive state. If the indication information indicates activation, the MAC entity of the terminal may indicate activation of a duplicate transmission operation of the PDCP entity to a higher layer. That is, when the indication information received through the MAC CE indicates activation of the redundant transmission function, the MAC entity of the terminal may transmit the indication to the upper layer (eg, the RRC layer) to indicate the activation.

When the indication information indicates activation, the transmitter 820 may transfer PDCP protocol data units (PDUs) copied from the PDCP entity to different Radio Link Control (RLC) entities and transmit the same data to a plurality of base stations. .

For example, when the redundant transmission function of the PDCP entity configured in the terminal is configured (or changed) by the above-described indication information, the PDCP entity copies data for transmission to the base station, and the plurality of PDCP entities connected to the PDCP entity. By transmitting to the RLC entity, the transmitter 820 may deliver the same data to the base station through a plurality of radio paths.

Meanwhile, the plurality of RLC entities may be configured in the terminal for each base station constituting the dual connectivity, and may be associated with one PDCP entity. When the indication information indicates deactivation and the redundant transmission operation of the PDCP entity is configured in the terminal, the PDCP entity may deliver the PDCP PDU to any one of the plurality of RLC entities. That is, if a duplicate transmission function in the PDCP entity is configured in the terminal, but the corresponding function is inactive, the PDCP entity transfers data only to one RLC entity among a plurality of RLC entities configured for dual connection, and the transmitter 820 ) May perform data transmission over a single path.

Meanwhile, the above-described redundant transmission function may be configured only for the data radio bearer (DRB). For example, the redundant transmission function in the PDCP entity may not be configured for the signaling radio bearer, but may be configured only for the data radio bearer.

In addition, the indication information may indicate whether the duplication transmission operation of the PDCP entity is activated to 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 terminal. In this case, the PDCP redundant transmission function is activated for a specific data radio bearer, but the PDCP redundant transmission function may be indicated with an inactive state. The base station described above may be a master base station or a secondary base station.

In addition, the controller 710 forms a dual connection with the plurality of base stations according to the above-described embodiments of the present invention, and controls the overall operation of the terminal 700 according to the overlapping data transmission to the base station. . In addition, the receiver 730 receives downlink control information, data, and messages from the base station through the corresponding channel, and the transmitter 720 transmits uplink control information, data, and messages to the base station through the corresponding channel.

8 is a diagram illustrating a configuration of a base station according to an embodiment.

Referring to FIG. 8, the base station 800 constituting dual connectivity with the terminal and receiving data redundantly configures redundant transmission in a Packet Data Convegence Protocol (PDCP) entity of the terminal for one or more radio bearers. A transmitter 820 for transmitting a radio resource control (RRC) message including configuration information for the terminal to the terminal, and for transmitting the indication information indicating whether to activate the duplicate transmission operation of the configured PDCP entity and the indication information indicating the activation In this case, the receiver may include a receiving unit 830 that duplicates the data transmitted from the PDCP entity of the terminal through the RLC entity of the base station and the RLC entity of another base station constituting a dual connection to the terminal.

As described above, the controller 810 may configure a dual connection to the terminal together with the other base station. In addition, the base stations constituting the dual connection may be set to use different radio access technology.

The transmitter 820 may transmit an RRC message including configuration information for configuring redundant transmission in the PDCP entity of the terminal for one or more radio bearers. 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 duplicate data is received from a PDCP entity of a terminal, a processing operation when a duplicate transmission function is activated or not, and a PDCP entity of a terminal through the two paths. It may include information for configuring the terminal so that at least one of the operation of transmitting the excitation data can be performed.

In addition, the transmitter 820 may perform the step of transmitting the indication information indicating whether to activate the duplicate transmission operation of the configured PDCP entity (S320). For example, the indication information may be transmitted through a medium access control control element (MAC CE). The indication information may include information indicating whether to change the redundant transmission function of the PDCP entity configured in the terminal to an activated state or an inactive state.

When the indication information indicates activation, the receiver 830 may duplicately receive data copied and transmitted from the PDCP entity of the terminal through the RLC entity of the base station and the RLC entity of another base station forming a dual connection to the terminal. . In this case, the terminal copies the PDCP protocol data unit (PDCP PDU) from the PDCP entity of the terminal and delivers it to different Radio Link Control (RLC) entities configured in the terminal, so that the base station 800 duplicates the same data through a plurality of RLC entities. To receive it. The plurality of RLC entities configured in the terminal may be configured in the terminal for each base station constituting the dual connection and may be associated with one PDCP entity. Similarly, the PDCP entity of the base station 800 may be associated with the RLC entity of the base station 800, and may also be associated with the RLC entity of another base station configuring a dual connection. In detail, the receiver 830 may receive data through a radio resource between the base station and the terminal, and may also receive the same data from another base station through an interface between the base stations. On the contrary, when the indication information indicates deactivation and the redundant transmission operation of the PDCP entity is configured in the terminal, the reception unit 830 may receive data only through the RLC entity of the base station.

Meanwhile, the above-described redundant transmission function may be configured only for the data radio bearer (DRB). For example, the redundant transmission function in the PDCP entity may not be configured for the signaling radio bearer, but may be configured only for the data radio bearer.

In addition, the indication information may indicate whether the duplication transmission operation of the PDCP entity is activated to 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 terminal. In this case, the PDCP redundant transmission function is activated for a specific data radio bearer, but the PDCP redundant transmission function may be indicated with an inactive state.

In addition, the control unit 810 forms a dual connection to the plurality of base stations and the terminal according to the above-described embodiments of the present invention, controls the uplink data redundant transmission of the terminal, and receives the redundantly transmitted data The overall operation of the base station 800 according to the control. In addition, the transmitter 820 and the receiver 830 are used to transmit and receive signals, messages, and data necessary for performing the above-described embodiments with the terminal and the secondary base station.

The standard contents or standard documents mentioned in the above embodiments are omitted to simplify the description of the specification and form a part of the present specification. Therefore, the addition of the contents of the standard and part of the standard documents to the specification or the description in the claims should be interpreted as falling within the scope of the present invention.

The above description is merely illustrative of the technical idea of the present invention, and those skilled in the art to which the present invention pertains may make various modifications and changes without departing from the essential characteristics of the present invention. Therefore, the embodiments disclosed in the present invention are not intended to limit the technical spirit of the present invention but to describe the present invention, and the scope of the technical idea of the present invention is not limited by these embodiments. The protection scope of the present invention should be interpreted by the following claims, and all technical ideas within the equivalent scope should be interpreted as being included in the scope of the present invention.

Claims (22)

In a method of duplex transmission of data by a terminal configured with a dual connection,
Receiving a Radio Resource Control (RRC) message containing configuration information for configuring redundant transmission in a Packet Data Convegence Protocol (PDCP) entity from a base station;
Configuring redundant transmission in the PDCP entity for one or more radio bearers;
Receiving indication information indicating whether to activate a duplicate transmission operation of the configured PDCP entity from the base station; And
If the indication information indicates the activation, copying the PDCP Protocol Data Unit (PDU) PPD (Protocol Data Unit) in the PDCP entity, and transmitting to different radio link control (RLC) entities, including transmitting the same data to a plurality of base stations, ,
The at least one radio bearer is a data radio bearer,
The instruction information is,
And instructing whether the PDCP entity activates a redundant transmission operation for each of the one or more data radio bearers, and is received through a MAC control element (MAC CE). The method of claim 1,
The terminal configured with the dual connection,
And transmit and receive data with the plurality of base stations configured to use different radio access technologies. delete The method of claim 1,
Receiving the indication information,
And if the indication information indicates activation, then the MAC entity further comprises instructing activation of a redundant transmission operation of the PDCP entity to a higher layer. The method of claim 1,
The PDCP entity is
And when the indication information indicates deactivation and a duplicate transmission operation of the PDCP entity is configured, delivering the PDCP PDU to any one of the plurality of RLC entities. delete In the method for receiving duplicated data by the base station configured with a dual connection with the terminal,
Transmitting a Radio Resource Control (RRC) message including configuration information for configuring redundant transmission in a Packet Data Convegence Protocol (PDCP) entity of a terminal for one or more radio bearers;
Transmitting indication information indicating whether to activate a duplicate transmission operation of the configured PDCP entity; And
If the indication information indicates activation, receiving the duplicated data transmitted from the PDCP entity of the terminal through the RLC entity of the base station and the RLC entity of another base station forming a dual connection to the terminal; But
The at least one radio bearer is a data radio bearer,
The instruction information is,
A method for indicating whether or not a duplicate transmission operation of the PDCP entity is activated for each of the one or more data radio bearers, and is transmitted through a MAC control element (MAC CE). The method of claim 7, wherein
The other base station,
And configured to use a different radio access technology from the base station, and configuring the dual connection with the base station for the terminal. delete The method of claim 7, wherein
PDCP entity of the base station,
And when the indication information indicates deactivation and a duplicate transmission operation of the PDCP entity is configured in the terminal, data is received only through the RLC entity of the base station. delete In a terminal configured with a dual connection for transmitting redundant data,
Receive a Radio Resource Control (RRC) message containing configuration information for configuring redundant transmission in a Packet Data Convegence Protocol (PDCP) entity from a base station, and activate a duplicate transmission operation of a PDCP entity configured from the base station. A receiving unit which receives instruction information indicating whether or not;
A control unit for configuring redundant transmission in the PDCP entity for one or more radio bearers; And
When the indication information indicates the activation, the PDCP includes a transmitter for copying a PDCP protocol data unit (PDU) PDU (PDU) data to different RLC (Radio Link Control) entity to transmit the same data to a plurality of base stations redundantly; ,
The at least one radio bearer is a data radio bearer,
The instruction information is,
A terminal for indicating whether or not to activate the duplicate transmission operation of the PDCP entity for each of the at least one data radio bearer, and is received through a MAC Control Element (MAC CE). The method of claim 12,
The terminal configured with the dual connection,
And a terminal configured to transmit and receive data with the plurality of base stations configured to use different radio access technologies. delete The method of claim 12,
The control unit,
And when the indication information indicates activation, controlling the MAC entity to indicate activation of a duplicate transmission operation of the PDCP entity to a higher layer. The method of claim 12,
The PDCP entity is
And when the indication information instructs deactivation and a duplicate transmission operation of the PDCP entity is configured, delivering the PDCP PDU to any one of the plurality of RLC entities. delete In the base station forming a dual connection with the terminal and receiving the data redundantly,
Transmitting a Radio Resource Control (RRC) message including configuration information for configuring redundant transmission in a Packet Data Convegence Protocol (PDCP) entity of a terminal for one or more radio bearers, and transmitting the configured PDCP entity A transmitter for transmitting indication information indicating whether to activate a duplicate transmission operation; And
When the indication information indicates the activation, the receiving unit for receiving duplicated data transmitted from the PDCP entity of the terminal through the RLC entity of the base station and the RLC entity of another base station forming a dual connection to the terminal; But
The at least one radio bearer is a data radio bearer,
The indication information is a base station for each of the one or more data radio bearer indicating whether or not to enable the duplicate transmission operation of the PDCP entity, and is transmitted via a MAC Control Element (MAC CE). The method of claim 18,
The other base station,
And a base station configured to use a different radio access technology from the base station, and configuring the dual connection with the base station for the terminal. delete The method of claim 18,
PDCP entity of the base station,
And when the indication information indicates deactivation and a duplicate transmission operation of the PDCP entity is configured in the terminal, data is received only through the RLC entity of the base station. delete

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